Imported Upstream version 1.2.0b
[debian/splat] / splat.cpp
index 2fe6fd42a616996b8233deeb5be5e240693427ba..119551071b19919bf3723bc1f47952a86923acfb 100644 (file)
--- a/splat.cpp
+++ b/splat.cpp
@@ -1,9 +1,17 @@
 /****************************************************************************
-*                    SPLAT: A Terrain Analysis Program                     *
-*             Copyright John A. Magliacane, KD2BD 1997-2004                *
-*                       Last update: 24-Jan-2004                           *
+*      SPLAT: An RF Signal Propagation Loss and Terrain Analysis Tool       *
+*                        Last update: 15-Mar-2007                          *
 *****************************************************************************
+*           Project started in 1997 by John A. Magliacane, KD2BD           *
+*****************************************************************************
+*                                                                          *
+*     Extensively modified by J. D. McDonald in Jan. 2004 to include        *
+*    the Longley-Rice propagation model using C++ code from NTIA/ITS.      *
 *                                                                          *
+*              See: http://flattop.its.bldrdoc.gov/itm.html                 *
+*                                                                          *
+*****************************************************************************
+*                                                                           *
 * This program is free software; you can redistribute it and/or modify it   *
 * under the terms of the GNU General Public License as published by the     *
 * Free Software Foundation; either version 2 of the License or any later    *
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License     *
 * for more details.                                                        *
 *                                                                          *
-*****************************************************************************
-*                                                                          *
-*     Extensively modified by J. D. McDonald in Jan. 2004 to include        *
-*    the Longley-Rice propagation model using C++ code from NTIA/ITS.      *
-*                                                                          *
-*              See: http://elbert.its.bldrdoc.gov/itm.html                  *
-*                                                                          *
 *****************************************************************************
  g++ -Wall -O3 -s -lm -lbz2 -fomit-frame-pointer itm.cpp splat.cpp -o splat 
 *****************************************************************************/
 #define ARRAYSIZE 30025
 #endif
 
-char string[255], sdf_path[255], opened=0, *splat_version={"1.1.0"};
+char   string[255], sdf_path[255], opened=0, *splat_version={"1.2.0b"};
 
 double TWOPI=6.283185307179586, HALFPI=1.570796326794896,
        PI=3.141592653589793, deg2rad=1.74532925199e-02,
        EARTHRADIUS=20902230.97, METERS_PER_MILE=1609.344,
-       METERS_PER_FOOT=0.3048, earthradius, max_range=0.0;
-
-int    min_north=0, max_north=0, min_west=0, max_west=0,
-       max_elevation=0, min_elevation=0, bzerror;
-
-struct site { double lat;
-             double lon;
-             double alt;
-             char name[50];
-           };
-
-struct { float lat[ARRAYSIZE];
-         float lon[ARRAYSIZE];
-         float elevation[ARRAYSIZE];
-         float distance[ARRAYSIZE];
-         int length;
-       } path;
-
-struct { int min_north;
-        int max_north;
-        int min_west;
-        int max_west;
-        int max_el;
-        int min_el;
-        short data[1200][1200];
-        unsigned char mask[1200][1200];
-       } dem[MAXSLOTS];
-
-struct {
-       double eps_dielect; 
-       double sgm_conductivity; 
-       double eno_ns_surfref;
-       double frq_mhz; 
-       double conf; 
-       double rel;
-       int radio_climate;  
-       int pol;
-       } LR;
+       METERS_PER_FOOT=0.3048, KM_PER_MILE=1.609344, earthradius,
+       max_range=0.0;
+
+int    min_north=90, max_north=-90, min_west=360, max_west=-1,
+       max_elevation=-32768, min_elevation=32768, bzerror, maxdB=230;
+
+unsigned char got_elevation_pattern=0, got_azimuth_pattern=0, metric=0;
+
+struct site {  double lat;
+               double lon;
+               float alt;
+               char name[50];
+           }   site;
+
+struct path {  double lat[ARRAYSIZE];
+               double lon[ARRAYSIZE];
+               double elevation[ARRAYSIZE];
+               double distance[ARRAYSIZE];
+               int length;
+           }   path;
+
+struct dem {   int min_north;
+               int max_north;
+               int min_west;
+               int max_west;
+               int max_el;
+               int min_el;
+               short data[1200][1200];
+               unsigned char mask[1200][1200];
+           }   dem[MAXSLOTS];
+
+struct LR {    double eps_dielect; 
+               double sgm_conductivity; 
+               double eno_ns_surfref;
+               double frq_mhz; 
+               double conf; 
+               double rel;
+               int radio_climate;  
+               int pol;
+               float antenna_pattern[361][1001];
+          }    LR;
 
 double elev_l[ARRAYSIZE+10];
 
@@ -122,13 +126,35 @@ double arccos(double x, double y)
        return result;
 }
 
+int ReduceAngle(double angle)
+{
+       /* This function normalizes the argument to
+          an integer angle between 0 and 180 degrees */
+
+       double temp;
+
+       temp=acos(cos(angle*deg2rad));
+
+       return (int)rint(temp/deg2rad);
+}
+
 char *dec2dms(double decimal)
 {
        /* Converts decimal degrees to degrees, minutes, seconds,
           (DMS) and returns the result as a character string. */
-       int degrees, minutes, seconds;
-       double a, b, c, d;
+
+       char    sign;
+       int     degrees, minutes, seconds;
+       double  a, b, c, d;
+
+       if (decimal<0.0)
+       {
+               decimal=-decimal;
+               sign=-1;
+       }
+
+       else
+               sign=1;
 
        a=floor(decimal);
        b=60.0*(decimal-a);
@@ -146,7 +172,7 @@ char *dec2dms(double decimal)
                seconds=59;
 
        string[0]=0;
-       sprintf(string,"%d%c %d\' %d\"", degrees, 176, minutes, seconds);
+       sprintf(string,"%d%c %d\' %d\"", degrees*sign, 176, minutes, seconds);
        return (string);
 }
 
@@ -158,8 +184,8 @@ int OrMask(double lat, double lon, int value)
           the mask based on the latitude and longitude of the area
           pointed to. */
 
-       int x, y, indx, minlat, minlon;
-       char found;
+       int     x, y, indx, minlat, minlon;
+       char    found;
 
        minlat=(int)floor(lat);
        minlon=(int)floor(lon);
@@ -176,8 +202,10 @@ int OrMask(double lat, double lon, int value)
                y=(int)(1199.0*(lon-floor(lon)));
 
                dem[indx].mask[x][y]|=value;
+
                return (dem[indx].mask[x][y]);
        }
+
        else
                return -1;
 }
@@ -196,9 +224,9 @@ double GetElevation(struct site location)
           represented by the digital elevation model data in memory.
           Function returns -5000.0 for locations not found in memory. */
 
-       char found;
-       int x, y, indx, minlat, minlon;
-       double elevation;
+       char    found;
+       int     x, y, indx, minlat, minlon;
+       double  elevation;
 
        elevation=-5000.0;
 
@@ -212,6 +240,7 @@ double GetElevation(struct site location)
        {
                if (minlat==dem[indx].min_north && minlon==dem[indx].min_west)
                {
+
                        elevation=3.28084*dem[indx].data[x][y];
                        found=1;
                }
@@ -220,12 +249,41 @@ double GetElevation(struct site location)
        return elevation;
 }
 
+int AddElevation(double lat, double lon, double height)
+{
+       /* This function adds a user-defined terrain feature
+          (in meters AGL) to the digital elevation model data
+          in memory.  Does nothing and returns 0 for locations
+          not found in memory. */
+
+       char    found;
+       int     x, y, indx, minlat, minlon;
+
+       minlat=(int)floor(lat);
+       minlon=(int)floor(lon);
+
+       x=(int)(1199.0*(lat-floor(lat)));
+       y=(int)(1199.0*(lon-floor(lon)));
+
+       for (indx=0, found=0; indx<MAXSLOTS && found==0; indx++)
+       {
+               if (minlat==dem[indx].min_north && minlon==dem[indx].min_west)
+               {
+
+                       dem[indx].data[x][y]+=(short)rint(height);
+                       found=1;
+               }
+       }
+       
+       return found;
+}
+
 double Distance(struct site site1, struct site site2)
 {
        /* This function returns the great circle distance
           in miles between any two site locations. */
 
-       double lat1, lon1, lat2, lon2, distance;
+       double  lat1, lon1, lat2, lon2, distance;
 
        lat1=site1.lat*deg2rad;
        lon1=site1.lon*deg2rad;
@@ -242,8 +300,8 @@ double Azimuth(struct site source, struct site destination)
        /* This function returns the azimuth (in degrees) to the
           destination as seen from the location of the source. */
 
-       double dest_lat, dest_lon, src_lat, src_lon,
-              beta, azimuth, diff, num, den, fraction;
+       double  dest_lat, dest_lon, src_lat, src_lon,
+               beta, azimuth, diff, num, den, fraction;
 
        dest_lat=destination.lat*deg2rad;
        dest_lon=destination.lon*deg2rad;
@@ -289,10 +347,10 @@ double Azimuth(struct site source, struct site destination)
        return (azimuth/deg2rad);               
 }
 
-double ElevationAngle(struct site local, struct site remote)
+double ElevationAngle(struct site source, struct site destination)
 {
        /* This function returns the angle of elevation (in degrees)
-          of the remote location as seen from the local site.
+          of the destination as seen from the source location.
           A positive result represents an angle of elevation (uptilt),
           while a negative result represents an angle of depression
           (downtilt), as referenced to a normal to the center of
@@ -300,10 +358,10 @@ double ElevationAngle(struct site local, struct site remote)
           
        register double a, b, dx;
 
-       a=GetElevation(remote)+remote.alt+earthradius;
-       b=GetElevation(local)+local.alt+earthradius;
+       a=GetElevation(destination)+destination.alt+earthradius;
+       b=GetElevation(source)+source.alt+earthradius;
 
-       dx=5280.0*Distance(local,remote);
+       dx=5280.0*Distance(source,destination);
 
        /* Apply the Law of Cosines */
 
@@ -313,24 +371,35 @@ double ElevationAngle(struct site local, struct site remote)
 void ReadPath(struct site source, struct site destination)
 {
        /* This function generates a sequence of latitude and
-          longitude positions between a source location and
-          a destination along a great circle path, and stores
-          elevation and distance information for points along
-          that path in the "path" structure for later use. */
+          longitude positions between source and destination
+          locations along a great circle path, and stores
+          elevation and distance information for points
+          along that path in the "path" structure. */
 
-       double azimuth, distance, lat1, lon1, beta,
-              den, num, lat2, lon2, total_distance;
-       int x1, y1, c;
-       struct site tempsite;
-
-       c=0;
+       int     c;
+       double  azimuth, distance, lat1, lon1, beta, den, num,
+               lat2, lon2, total_distance, x, y, path_length,
+               increment;
+       struct  site tempsite;
 
        lat1=source.lat*deg2rad;
        lon1=source.lon*deg2rad;
+
+       lat2=destination.lat*deg2rad;
+       lon2=destination.lon*deg2rad;
+
        azimuth=Azimuth(source,destination)*deg2rad;
+
        total_distance=Distance(source,destination);
 
-       for (distance=0; distance<=total_distance; distance+=0.04)
+       x=68755.0*acos(cos(lon1-lon2));         /* 1200 samples per degree */
+       y=68755.0*acos(cos(lat1-lat2));         /* 68755 samples per radian */
+
+       path_length=sqrt((x*x)+(y*y));          /* Total number of samples */
+
+       increment=total_distance/path_length;   /* Miles per sample */
+
+       for (distance=0, c=0; distance<=total_distance; distance+=increment)
        {
                beta=distance/3959.0;
                lat2=asin(sin(lat1)*cos(beta)+cos(azimuth)*sin(beta)*cos(lat1));
@@ -363,30 +432,102 @@ void ReadPath(struct site source, struct site destination)
                lat2=lat2/deg2rad;
                lon2=lon2/deg2rad;
 
-               x1=(int)(1199.0*(lat2-floor(lat2)));
-               y1=(int)(1199.0*(lon2-floor(lon2)));
+               if (c<ARRAYSIZE)
+               {
+                       path.lat[c]=lat2;
+                       path.lon[c]=lon2;
+                       tempsite.lat=lat2;
+                       tempsite.lon=lon2;
+                       path.elevation[c]=GetElevation(tempsite);
+                       path.distance[c]=distance;
+                       c++;
+               }
+       }
+
+       /* Make sure exact destination point is recorded at path.length-1 */
 
-               path.lat[c]=lat2;
-               path.lon[c]=lon2;
-               tempsite.lat=lat2;
-               tempsite.lon=lon2;
-               path.elevation[c]=GetElevation(tempsite);
-               path.distance[c]=distance;
+       if (c<ARRAYSIZE)
+       {
+               path.lat[c]=destination.lat;
+               path.lon[c]=destination.lon;
+               path.elevation[c]=GetElevation(destination);
+               path.distance[c]=total_distance;
                c++;
        }
 
-       /* Make sure exact destination point is recorded at path.length-1 */
+       if (c<ARRAYSIZE)
+               path.length=c;
+       else
+               path.length=ARRAYSIZE-1;
+}
+
+double ElevationAngle2(struct site source, struct site destination, double er)
+{
+       /* This function returns the angle of elevation (in degrees)
+          of the destination as seen from the source location, UNLESS
+          the path between the sites is obstructed, in which case, the
+          elevation angle to the first obstruction is returned instead.
+          "er" represents the earth radius. */
+
+       int     x;
+       char    block=0;
+       double  source_alt, destination_alt, cos_xmtr_angle,
+               cos_test_angle, test_alt, elevation, distance,
+               source_alt2, first_obstruction_angle=0.0;
+       struct  path temp;
+
+       temp=path;
+
+       ReadPath(source,destination);
+
+       distance=5280.0*Distance(source,destination);
+       source_alt=er+source.alt+GetElevation(source);
+       destination_alt=er+destination.alt+GetElevation(destination);
+       source_alt2=source_alt*source_alt;
+
+       /* Calculate the cosine of the elevation angle of the
+          destination (receiver) as seen by the source (transmitter). */
+
+       cos_xmtr_angle=((source_alt2)+(distance*distance)-(destination_alt*destination_alt))/(2.0*source_alt*distance);
+
+       /* Test all points in between source and destination locations to
+          see if the angle to a topographic feature generates a higher
+          elevation angle than that produced by the destination.  Begin
+          at the source since we're interested in identifying the FIRST
+          obstruction along the path between source and destination. */
+       for (x=2, block=0; x<path.length && block==0; x++)
+       {
+               distance=5280.0*path.distance[x];
+
+               test_alt=earthradius+path.elevation[x];
+
+               cos_test_angle=((source_alt2)+(distance*distance)-(test_alt*test_alt))/(2.0*source_alt*distance);
 
-       x1=(int)(1199.0*(destination.lat-floor(destination.lat)));
-       y1=(int)(1199.0*(destination.lon-floor(destination.lon)));
+               /* Compare these two angles to determine if
+                  an obstruction exists.  Since we're comparing
+                  the cosines of these angles rather than
+                  the angles themselves, the sense of the
+                  following "if" statement is reversed from
+                  what it would be if the angles themselves
+                  were compared. */
+
+               if (cos_xmtr_angle>cos_test_angle)
+               {
+                       block=1;
+                       first_obstruction_angle=((acos(cos_test_angle))/deg2rad)-90.0;
+               }
+       }
+
+       if (block)
+               elevation=first_obstruction_angle;
 
-       path.lat[c]=destination.lat;
-       path.lon[c]=destination.lon;
-       path.elevation[c]=GetElevation(destination);
-       path.distance[c]=total_distance;
-       c++;
+       else
+               elevation=((acos(cos_xmtr_angle))/deg2rad)-90.0;
+
+       path=temp;
 
-       path.length=c;
+       return elevation;
 }
 
 double AverageTerrain(struct site source, double azimuthx, double start_distance, double end_distance)
@@ -399,9 +540,9 @@ double AverageTerrain(struct site source, double azimuthx, double start_distance
           memory to complete the survey (critical error), then
           -9999.0 is returned. */
  
-       int c, samples, endpoint;
-       double beta, lat1, lon1, lat2, lon2, num, den, azimuth, terrain=0.0;
-       struct site destination;
+       int     c, samples, endpoint;
+       double  beta, lat1, lon1, lat2, lon2, num, den, azimuth, terrain=0.0;
+       struct  site destination;
 
        lat1=source.lat*deg2rad;
        lon1=source.lon*deg2rad;
@@ -490,9 +631,9 @@ double haat(struct site antenna)
           error occurs, such as a lack of SDF data to complete the
           survey, -5000.0 is returned. */
 
-       int azi, c;
-       char error=0;
-       double terrain, avg_terrain, haat, sum=0.0;
+       int     azi, c;
+       char    error=0;
+       double  terrain, avg_terrain, haat, sum=0.0;
 
        /* Calculate the average terrain between 2 and 10 miles
           from the antenna site at azimuths of 0, 45, 90, 135,
@@ -522,6 +663,27 @@ double haat(struct site antenna)
        }
 }
 
+float LonDiff(float lon1, float lon2)
+{
+       /* This function returns the short path longitudinal
+          difference between longitude1 and longitude2 
+          as an angle between -180.0 and +180.0 degrees.
+          If lon1 is west of lon2, the result is positive.
+          If lon1 is east of lon2, the result is negative. */
+
+       float diff;
+
+       diff=lon1-lon2;
+
+       if (diff<=-180.0)
+               diff+=360.0;
+
+       if (diff>=180.0)
+               diff-=360.0;
+
+       return diff;
+}
+
 void PlaceMarker(struct site location)
 {
        /* This function places text and marker data in the mask array
@@ -546,7 +708,7 @@ void PlaceMarker(struct site location)
        lat=location.lat;
        lon=location.lon;
 
-       if (lat<xmax && lat>xmin && lon<ymax && lon>ymin)
+       if (lat<xmax && lat>xmin && (LonDiff(lon,ymax)<0.0) && (LonDiff(lon,ymin)>0.0))
        {
                p1=1.0/1200.0;
                p3=3.0/1200.0;
@@ -561,7 +723,7 @@ void PlaceMarker(struct site location)
                /* Is Marker Position Clear Of Text Or Other Markers? */
 
                for (x=lat-p3; (x<=xmax && x>=xmin && x<=lat+p3); x+=p1)
-                       for (y=lon-p3; (y<=ymax && y>=ymin && y<=lon+p3); y+=p1)
+                       for (y=lon-p3; (LonDiff(y,ymax)<=0.0) && (LonDiff(y,ymin)>=0.0) && (LonDiff(y,lon+p3)<=0.0); y+=p1)
                                occupied|=(GetMask(x,y)&2);
 
                if (occupied==0)
@@ -573,7 +735,7 @@ void PlaceMarker(struct site location)
 
                        label_length=p1*(double)(strlen(location.name)<<3);
 
-                       if (((lon+label_length)<=ymax) && (lon-label_length)>=ymin)
+                       if ((LonDiff(lon+label_length,ymax)<=0.0) && (LonDiff(lon-label_length,ymin)>=0.0))
                        {
                                /* Default: Centered Text */
 
@@ -638,7 +800,7 @@ void PlaceMarker(struct site location)
 
                        if (ok2print==0)
                        {
-                               if ((lon-label_length)>=ymin)
+                               if (LonDiff(lon-label_length,ymin)>=0.0)
                                {
                                        /* Position Text To The
                                           Right Of The Marker */
@@ -703,7 +865,7 @@ void PlaceMarker(struct site location)
                           coordinates that describe the placement of the text
                           on the map. */
        
-                       if (ok2print && textx!=0.0 && texty!=0.0)
+                       if (ok2print)
                        {
                                /* Draw Text */
 
@@ -720,6 +882,7 @@ void PlaceMarker(struct site location)
                                                        if (byte&c)
                                                                OrMask(x,y,2);
                                        }
+
                                        x-=p1;
                                        y=texty;
                                }
@@ -728,7 +891,7 @@ void PlaceMarker(struct site location)
                                   On Location Specified */
        
                                for (x=lat-p3; (x<=xmax && x>=xmin && x<=lat+p3); x+=p1)
-                                       for (y=lon-p3; (y<=ymax && y>=ymin && y<=lon+p3); y+=p1)
+                                       for (y=lon-p3; (LonDiff(y,ymax)<=0.0) && (LonDiff(y,ymin)>=0.0) && (LonDiff(y,lon+p3)<=0.0); y+=p1)
                                                OrMask(x,y,2);
                        }
                }
@@ -746,10 +909,9 @@ double ReadBearing(char *input)
           embedded within the numbers expressed in the
           input string.  Decimal seconds are permitted. */
  
-       double bearing=0.0;
-       char string[20];
-       int a, b, length, degrees, minutes;
-       double seconds;
+       double  seconds, bearing=0.0;
+       char    string[20];
+       int     a, b, length, degrees, minutes;
 
        /* Copy "input" to "string", and ignore any extra
           spaces that might be present in the process. */
@@ -759,7 +921,7 @@ double ReadBearing(char *input)
 
        for (a=0, b=0; a<length && a<18; a++)
        {
-               if ((input[a]!=32 && input[a]!='\n') || (input[a]==32 && input[a+1]!=32 && b!=0))
+               if ((input[a]!=32 && input[a]!='\n') || (input[a]==32 && input[a+1]!=32 && input[a+1]!='\n' && b!=0))
                {
                        string[b]=input[a];
                        b++;
@@ -782,12 +944,16 @@ double ReadBearing(char *input)
        if (b==2)  /* Degree, Minute, Second Format (40 08 23) */
        {
                sscanf(string,"%d %d %lf",&degrees, &minutes, &seconds);
-               bearing=(double)degrees+((double)minutes/60)+(seconds/3600);
+
+               bearing=(double)abs(degrees)+((double)abs(minutes)/60)+(fabs(seconds)/3600);
+
+               if ((degrees<0) || (minutes<0) || (seconds<0.0))
+                       bearing=-bearing;
        }
 
        /* Anything else returns a 0.0 */
 
-       if (bearing>360.0 || bearing<0.0)
+       if (bearing>360.0 || bearing<-90.0)
                bearing=0.0;
 
        return bearing;
@@ -803,10 +969,10 @@ struct site LoadQTH(char *filename)
           or 'm', or by the word "meters" or "Meters", in which
           case meters is assumed, and is handled accordingly. */
 
-       int x;
-       char string[50], qthfile[255];
-       struct site tempsite;
-       FILE *fd=NULL;
+       int     x;
+       char    string[50], qthfile[255];
+       struct  site tempsite;
+       FILE    *fd=NULL;
 
        for (x=0; filename[x]!='.' && filename[x]!=0 && x<250; x++)
                qthfile[x]=filename[x];
@@ -817,8 +983,8 @@ struct site LoadQTH(char *filename)
        qthfile[x+3]='h';
        qthfile[x+4]=0;
 
-       tempsite.lat=0.0;
-       tempsite.lon=0.0;
+       tempsite.lat=91.0;
+       tempsite.lon=361.0;
        tempsite.alt=0.0;
        tempsite.name[0]=0;
 
@@ -862,219 +1028,608 @@ struct site LoadQTH(char *filename)
                if (string[x]=='M' || string[x]=='m')
                {
                        string[x]=0;
-                       sscanf(string,"%lf",&tempsite.alt);
+                       sscanf(string,"%f",&tempsite.alt);
                        tempsite.alt*=3.28084;
                }
 
                else
                {
                        string[x]=0;
-                       sscanf(string,"%lf",&tempsite.alt);
+                       sscanf(string,"%f",&tempsite.alt);
                }
        }
 
        return tempsite;
 }
 
-int LoadSDF_SDF(char *name)
+void LoadPAT(char *filename)
 {
-       /* This function reads uncompressed SPLAT Data Files (.sdf)
-          containing digital elevation model data into memory.
-          Elevation data, maximum and minimum elevations, and
-          quadrangle limits are stored in the first available
-          dem[] structure. */
-
-       int x, y, data, indx, minlat, minlon, maxlat, maxlon;
-       char found, free_slot=0, line[20], sdf_file[255], path_plus_name[255];
-       FILE *fd;
+       /* This function reads and processes antenna pattern (.az
+          and .el) files that correspond in name to previously
+          loaded SPLAT! .lrp files.  */
+
+       int     a, b, w, x, y, z, last_index, next_index, span;
+       char    string[255], azfile[255], elfile[255], *pointer=NULL;
+       float   az, xx, elevation, amplitude, rotation, valid1, valid2,
+               delta, azimuth[361], azimuth_pattern[361], el_pattern[10001],
+               elevation_pattern[361][1001], slant_angle[361], tilt,
+               mechanical_tilt, tilt_azimuth, tilt_increment, sum;
+       FILE    *fd=NULL;
+       unsigned char read_count[10001];
 
-       for (x=0; name[x]!='.' && name[x]!=0 && x<250; x++)
-               sdf_file[x]=name[x];
+       for (x=0; filename[x]!='.' && filename[x]!=0 && x<250; x++)
+       {
+               azfile[x]=filename[x];
+               elfile[x]=filename[x];
+       }
 
-       sdf_file[x]=0;
+       azfile[x]='.';
+       azfile[x+1]='a';
+       azfile[x+2]='z';
+       azfile[x+3]=0;
 
-       /* Parse filename for minimum latitude and longitude values */
+       elfile[x]='.';
+       elfile[x+1]='e';
+       elfile[x+2]='l';
+       elfile[x+3]=0;
 
-       sscanf(sdf_file,"%d:%d:%d:%d",&minlat,&maxlat,&minlon,&maxlon);
+       rotation=0.0;
 
-       sdf_file[x]='.';
-       sdf_file[x+1]='s';
-       sdf_file[x+2]='d';
-       sdf_file[x+3]='f';
-       sdf_file[x+4]=0;
+       /* Load .az antenna pattern file */
 
-       /* Is it already in memory? */
+       fd=fopen(azfile,"r");
 
-       for (indx=0, found=0; indx<MAXSLOTS && found==0; indx++)
+       if (fd!=NULL)
        {
-               if (minlat!=0 && minlon!=0)
+               /* Clear azimuth pattern array */
+
+               for (x=0; x<=360; x++)
                {
-                       if (minlat==dem[indx].min_north && minlon==dem[indx].min_west && maxlat==dem[indx].max_north && maxlon==dem[indx].max_west)
-                               found=1;
+                       azimuth[x]=0.0;
+                       read_count[x]=0;
                }
-       }
 
-       /* Is room available to load it? */
 
-       if (found==0)
-       {       
-               for (indx=0, free_slot=0; indx<MAXSLOTS && free_slot==0; indx++)
-                       if (dem[indx].max_north==0 && dem[indx].max_west==0)
-                               free_slot=1;
-       }
+               /* Read azimuth pattern rotation
+                  in degrees measured clockwise
+                  from true North. */
 
-       indx--;
+               fgets(string,254,fd);
+               pointer=strchr(string,';');
 
-       if (free_slot && found==0 && indx>=0 && indx<MAXSLOTS && minlat!=0 && minlon!=0)
-       {
-               strncpy(path_plus_name,sdf_path,255);
-               strncat(path_plus_name,sdf_file,255);
+               if (pointer!=NULL)
+                       *pointer=0;
 
-               fd=fopen(path_plus_name,"rb");
+               sscanf(string,"%f",&rotation);
 
-               if (fd!=NULL)
+
+               /* Read azimuth (degrees) and corresponding
+                  normalized field radiation pattern amplitude
+                  (0.0 to 1.0) until EOF is reached. */
+
+               fgets(string,254,fd);
+               pointer=strchr(string,';');
+
+               if (pointer!=NULL)
+                       *pointer=0;
+
+               sscanf(string,"%f %f",&az, &amplitude);
+
+               do
                {
-                       fprintf(stdout,"Loading \"%s\" into slot %d...",path_plus_name,indx+1);
-                       fflush(stdout);
+                       x=(int)rintf(az);
 
-                       fgets(line,19,fd);
-                       sscanf(line,"%d",&dem[indx].max_west);
+                       if (x>=0 && x<=360 && fd!=NULL)
+                       {
+                               azimuth[x]+=amplitude;
+                               read_count[x]++;
+                       }
 
-                       fgets(line,19,fd);
-                       sscanf(line,"%d",&dem[indx].min_north);
+                       fgets(string,254,fd);
+                       pointer=strchr(string,';');
 
-                       fgets(line,19,fd);
-                       sscanf(line,"%d",&dem[indx].min_west);
+                       if (pointer!=NULL)
+                               *pointer=0;
 
-                       fgets(line,19,fd);
-                       sscanf(line,"%d",&dem[indx].max_north);
+                       sscanf(string,"%f %f",&az, &amplitude);
 
-                       for (x=0; x<1200; x++)
-                               for (y=0; y<1200; y++)
-                               {
-                                       fgets(line,19,fd);
-                                       sscanf(line,"%d",&data);
-                                       dem[indx].data[x][y]=data;
+               } while (feof(fd)==0);
 
-                                       if (data>dem[indx].max_el)
-                                               dem[indx].max_el=data;
+               fclose(fd);
 
-                                       if (dem[indx].min_el==0)
-                                               dem[indx].min_el=data;
-                                       else
-                                       {
-                                                if (data<dem[indx].min_el)
-                                                       dem[indx].min_el=data;
-                                       }
-                               }
 
-                       fclose(fd);
+               /* Handle 0=360 degree ambiguity */
 
-                       if (min_elevation==0)
-                               min_elevation=dem[indx].min_el;
+               if ((read_count[0]==0) && (read_count[360]!=0))
+               {
+                       read_count[0]=read_count[360];
+                       azimuth[0]=azimuth[360];
+               }
 
-                       else
-                       {
-                               if (dem[indx].min_el<min_elevation)
-                                       min_elevation=dem[indx].min_el;
-                       }
+               if ((read_count[0]!=0) && (read_count[360]==0))
+               {
+                       read_count[360]=read_count[0];
+                       azimuth[360]=azimuth[0];
+               }
 
-                       if (dem[indx].max_el>max_elevation)
-                               max_elevation=dem[indx].max_el;
+               /* Average pattern values in case more than
+                   one was read for each degree of azimuth. */
 
-                       if (dem[indx].max_north>max_north)
-                               max_north=dem[indx].max_north;
+               for (x=0; x<=360; x++)
+               {
+                       if (read_count[x]>1)
+                               azimuth[x]/=(float)read_count[x];
+               }
 
-                       if (dem[indx].max_west>max_west)
-                               max_west=dem[indx].max_west;
+               /* Interpolate missing azimuths
+                  to completely fill the array */
 
-                       if (min_north==0)
-                               min_north=dem[indx].min_north;
-                       else
+               last_index=-1;
+               next_index=-1;
+
+               for (x=0; x<=360; x++)
+               {
+                       if (read_count[x]!=0)
                        {
-                               if (dem[indx].min_north<min_north)
-                                       min_north=dem[indx].min_north;
+                               if (last_index==-1)
+                                       last_index=x;
+                               else
+                                       next_index=x;
                        }
 
-                       if (min_west==0)
-                               min_west=dem[indx].min_west;
-                       else
+                       if (last_index!=-1 && next_index!=-1)
                        {
-                               if (dem[indx].min_west<min_west)
-                                       min_west=dem[indx].min_west;
-                       }
+                               valid1=azimuth[last_index];
+                               valid2=azimuth[next_index];
 
-                       fprintf(stdout," Done!\n");
-                       fflush(stdout);
-                       return 1;
+                               span=next_index-last_index;
+                               delta=(valid2-valid1)/(float)span;
+
+                               for (y=last_index+1; y<next_index; y++)
+                                       azimuth[y]=azimuth[y-1]+delta;
+
+                               last_index=y;
+                               next_index=-1;
+                       }
                }
 
-               else
-                       return -1;
-       }
+               /* Perform azimuth pattern rotation
+                  and load azimuth_pattern[361] with
+                  azimuth pattern data in its final form. */
 
-       else
-               return 0;
-}
+               for (x=0; x<360; x++)
+               {
+                       y=x+(int)rintf(rotation);
 
-char *BZfgets(BZFILE *bzfd, unsigned length)
-{
-       /* This function returns at most one less than 'length' number
-          of characters from a bz2 compressed file whose file descriptor
-          is pointed to by *bzfd.  In operation, a buffer is filled with
-          uncompressed data (size = BZBUFFER), which is then parsed
-          and doled out as NULL terminated character strings every time
-          this function is invoked.  A NULL string indicates an EOF
-          or error condition. */
+                       if (y>=360)
+                               y-=360;
 
-       static int x, y, nBuf;
-       static char buffer[BZBUFFER+1], output[BZBUFFER+1];
-       char done=0;
+                       azimuth_pattern[y]=azimuth[x];
+               }
 
-       if (opened!=1 && bzerror==BZ_OK)
-       {
-               /* First time through.  Initialize everything! */
+               azimuth_pattern[360]=azimuth_pattern[0];
 
-               x=0;
-               y=0;
-               nBuf=0;
-               opened=1;
-               output[0]=0;
+               got_azimuth_pattern=255;
        }
 
-       do
+       /* Read and process .el file */
+
+       fd=fopen(elfile,"r");
+
+       if (fd!=NULL)
        {
-               if (x==nBuf && bzerror!=BZ_STREAM_END && bzerror==BZ_OK && opened)
+               for (x=0; x<=10000; x++)
                {
-                       /* Uncompress data into a static buffer */
-
-                       nBuf=BZ2_bzRead(&bzerror, bzfd, buffer, BZBUFFER);
-                       buffer[nBuf]=0;
-                       x=0;
+                       el_pattern[x]=0.0;
+                       read_count[x]=0;
                }
 
-               /* Build a string from buffer contents */
+               /* Read mechanical tilt (degrees) and
+                  tilt azimuth in degrees measured
+                  clockwise from true North. */  
 
-               output[y]=buffer[x];
+               fgets(string,254,fd);
+               pointer=strchr(string,';');
 
-               if (output[y]=='\n' || output[y]==0 || y==(int)length-1)
-               {
-                       output[y+1]=0;
-                       done=1;
-                       y=0;
-               }
+               if (pointer!=NULL)
+                       *pointer=0;
 
-               else
-                       y++;
-               x++;
+               sscanf(string,"%f %f",&mechanical_tilt, &tilt_azimuth);
 
-       } while (done==0);
+               /* Read elevation (degrees) and corresponding
+                  normalized field radiation pattern amplitude
+                  (0.0 to 1.0) until EOF is reached. */
 
-       if (output[0]==0)
-               opened=0;
+               fgets(string,254,fd);
+               pointer=strchr(string,';');
 
-       return (output);
-}
+               if (pointer!=NULL)
+                       *pointer=0;
+
+               sscanf(string,"%f %f", &elevation, &amplitude);
+
+               while (feof(fd)==0)
+               {
+                       /* Read in normalized radiated field values
+                          for every 0.01 degrees of elevation between
+                          -10.0 and +90.0 degrees */
+
+                       x=(int)rintf(100.0*(elevation+10.0));
+
+                       if (x>=0 && x<=10000)
+                       {
+                               el_pattern[x]+=amplitude;
+                               read_count[x]++;
+                       }
+
+                       fgets(string,254,fd);
+                       pointer=strchr(string,';');
+
+                       if (pointer!=NULL)
+                               *pointer=0;
+
+                       sscanf(string,"%f %f", &elevation, &amplitude);
+               }
+
+               fclose(fd);
+
+               /* Average the field values in case more than
+                  one was read for each 0.01 degrees of elevation. */
+
+               for (x=0; x<=10000; x++)
+               {
+                       if (read_count[x]>1)
+                               el_pattern[x]/=(float)read_count[x];
+               }
+
+               /* Interpolate between missing elevations (if
+                  any) to completely fill the array and provide
+                  radiated field values for every 0.01 degrees of
+                  elevation. */
+
+               last_index=-1;
+               next_index=-1;
+
+               for (x=0; x<=10000; x++)
+               {
+                       if (read_count[x]!=0)
+                       {
+                               if (last_index==-1)
+                                       last_index=x;
+                               else
+                                       next_index=x;
+                       }
+
+                       if (last_index!=-1 && next_index!=-1)
+                       {
+                               valid1=el_pattern[last_index];
+                               valid2=el_pattern[next_index];
+
+                               span=next_index-last_index;
+                               delta=(valid2-valid1)/(float)span;
+
+                               for (y=last_index+1; y<next_index; y++)
+                                       el_pattern[y]=el_pattern[y-1]+delta;
+
+                               last_index=y;
+                               next_index=-1;
+                       }
+               }
+
+               /* Fill slant_angle[] array with offset angles based
+                  on the antenna's mechanical beam tilt (if any)
+                  and tilt direction (azimuth). */
+
+               if (mechanical_tilt==0.0)
+               {
+                       for (x=0; x<=360; x++)
+                               slant_angle[x]=0.0;
+               }
+
+               else
+               {
+                       tilt_increment=mechanical_tilt/90.0;
+
+                       for (x=0; x<=360; x++)
+                       {
+                               xx=(float)x;
+                               y=(int)rintf(tilt_azimuth+xx);
+
+                               while (y>=360)
+                                       y-=360;
+
+                               while (y<0)
+                                       y+=360;
+
+                               if (x<=180)
+                                       slant_angle[y]=-(tilt_increment*(90.0-xx));
+
+                               if (x>180)
+                                       slant_angle[y]=-(tilt_increment*(xx-270.0));
+                       }
+               }
+
+               slant_angle[360]=slant_angle[0];   /* 360 degree wrap-around */
+
+               for (w=0; w<=360; w++)
+               {
+                       tilt=slant_angle[w];
+
+                       /** Convert tilt angle to
+                           an array index offset **/
+
+                       y=(int)rintf(100.0*tilt);
+
+                       /* Copy shifted el_pattern[10001] field
+                          values into elevation_pattern[361][1001]
+                          at the corresponding azimuth, downsampling
+                          (averaging) along the way in chunks of 10. */
+
+                       for (x=y, z=0; z<=1000; x+=10, z++)
+                       {
+                               for (sum=0.0, a=0; a<10; a++)
+                               {
+                                       b=a+x;
+
+                                       if (b>=0 && b<=10000)
+                                               sum+=el_pattern[b];
+                                       if (b<0)
+                                               sum+=el_pattern[0];
+                                       if (b>10000)
+                                               sum+=el_pattern[10000];
+                               }
+
+                               elevation_pattern[w][z]=sum/10.0;
+                       }
+               }
+
+               got_elevation_pattern=255;
+       }
+
+       for (x=0; x<=360; x++)
+       {
+               for (y=0; y<=1000; y++)
+               {
+                       if (got_elevation_pattern)
+                               elevation=elevation_pattern[x][y];
+                       else
+                               elevation=1.0;
+
+                       if (got_azimuth_pattern)
+                               az=azimuth_pattern[x];
+                       else
+                               az=1.0;
+
+                       LR.antenna_pattern[x][y]=az*elevation;
+               }
+       }
+}
+
+int LoadSDF_SDF(char *name)
+{
+       /* This function reads uncompressed SPLAT Data Files (.sdf)
+          containing digital elevation model data into memory.
+          Elevation data, maximum and minimum elevations, and
+          quadrangle limits are stored in the first available
+          dem[] structure. */
+
+       int     x, y, data, indx, minlat, minlon, maxlat, maxlon;
+       char    found, free_slot=0, line[20], sdf_file[255],
+               path_plus_name[255];
+       FILE    *fd;
+
+       for (x=0; name[x]!='.' && name[x]!=0 && x<250; x++)
+               sdf_file[x]=name[x];
+
+       sdf_file[x]=0;
+
+       /* Parse filename for minimum latitude and longitude values */
+
+       sscanf(sdf_file,"%d:%d:%d:%d",&minlat,&maxlat,&minlon,&maxlon);
+
+       sdf_file[x]='.';
+       sdf_file[x+1]='s';
+       sdf_file[x+2]='d';
+       sdf_file[x+3]='f';
+       sdf_file[x+4]=0;
+
+       /* Is it already in memory? */
+
+       for (indx=0, found=0; indx<MAXSLOTS && found==0; indx++)
+       {
+               if (minlat==dem[indx].min_north && minlon==dem[indx].min_west && maxlat==dem[indx].max_north && maxlon==dem[indx].max_west)
+                       found=1;
+       }
+
+       /* Is room available to load it? */
+
+       if (found==0)
+       {       
+               for (indx=0, free_slot=0; indx<MAXSLOTS && free_slot==0; indx++)
+                       if (dem[indx].max_north==-90)
+                               free_slot=1;
+       }
+
+       indx--;
+
+       if (free_slot && found==0 && indx>=0 && indx<MAXSLOTS)
+       {
+               /* Search for SDF file in current working directory first */
+
+               strncpy(path_plus_name,sdf_file,255);
+
+               fd=fopen(path_plus_name,"rb");
+
+               if (fd==NULL)
+               {
+                       /* Next, try loading SDF file from path specified
+                          in $HOME/.splat_path file or by -d argument */
+
+                       strncpy(path_plus_name,sdf_path,255);
+                       strncat(path_plus_name,sdf_file,255);
+
+                       fd=fopen(path_plus_name,"rb");
+               }
+
+               if (fd!=NULL)
+               {
+                       fprintf(stdout,"Loading \"%s\" into slot %d...",path_plus_name,indx+1);
+                       fflush(stdout);
+
+                       fgets(line,19,fd);
+                       sscanf(line,"%d",&dem[indx].max_west);
+
+                       fgets(line,19,fd);
+                       sscanf(line,"%d",&dem[indx].min_north);
+
+                       fgets(line,19,fd);
+                       sscanf(line,"%d",&dem[indx].min_west);
+
+                       fgets(line,19,fd);
+                       sscanf(line,"%d",&dem[indx].max_north);
+
+                       for (x=0; x<1200; x++)
+                               for (y=0; y<1200; y++)
+                               {
+                                       fgets(line,19,fd);
+                                       sscanf(line,"%d",&data);
+
+                                       dem[indx].data[x][y]=data;
+
+                                       if (data>dem[indx].max_el)
+                                               dem[indx].max_el=data;
+
+                                       if (data<dem[indx].min_el)
+                                               dem[indx].min_el=data;
+                               }
+
+                       fclose(fd);
+
+                       if (dem[indx].min_el<min_elevation)
+                               min_elevation=dem[indx].min_el;
+
+                       if (dem[indx].max_el>max_elevation)
+                               max_elevation=dem[indx].max_el;
+
+                       if (max_north==-90)
+                               max_north=dem[indx].max_north;
+
+                       else if (dem[indx].max_north>max_north)
+                               max_north=dem[indx].max_north;
+
+                       if (min_north==90)
+                               min_north=dem[indx].min_north;
+
+                       else if (dem[indx].min_north<min_north)
+                               min_north=dem[indx].min_north;
+
+                       if (max_west==-1)
+                               max_west=dem[indx].max_west;
+
+                       else
+                       {
+                               if (abs(dem[indx].max_west-max_west)<180)
+                               {
+                                       if (dem[indx].max_west>max_west)
+                                               max_west=dem[indx].max_west;
+                               }
+
+                               else
+                               {
+                                       if (dem[indx].max_west<max_west)
+                                               max_west=dem[indx].max_west;
+                               }
+                       }
+
+                       if (min_west==360)
+                               min_west=dem[indx].min_west;
+
+                       else
+                       {
+                               if (abs(dem[indx].min_west-min_west)<180)
+                               {
+                                       if (dem[indx].min_west<min_west)
+                                               min_west=dem[indx].min_west;
+                               }
+
+                               else
+                               {
+                                       if (dem[indx].min_west>min_west)
+                                               min_west=dem[indx].min_west;
+                               }
+                       }
+
+                       fprintf(stdout," Done!\n");
+                       fflush(stdout);
+                       return 1;
+               }
+
+               else
+                       return -1;
+       }
+
+       else
+               return 0;
+}
+
+char *BZfgets(BZFILE *bzfd, unsigned length)
+{
+       /* This function returns at most one less than 'length' number
+          of characters from a bz2 compressed file whose file descriptor
+          is pointed to by *bzfd.  In operation, a buffer is filled with
+          uncompressed data (size = BZBUFFER), which is then parsed
+          and doled out as NULL terminated character strings every time
+          this function is invoked.  A NULL string indicates an EOF
+          or error condition. */
+
+       static int x, y, nBuf;
+       static char buffer[BZBUFFER+1], output[BZBUFFER+1];
+       char done=0;
+
+       if (opened!=1 && bzerror==BZ_OK)
+       {
+               /* First time through.  Initialize everything! */
+
+               x=0;
+               y=0;
+               nBuf=0;
+               opened=1;
+               output[0]=0;
+       }
+
+       do
+       {
+               if (x==nBuf && bzerror!=BZ_STREAM_END && bzerror==BZ_OK && opened)
+               {
+                       /* Uncompress data into a static buffer */
+
+                       nBuf=BZ2_bzRead(&bzerror, bzfd, buffer, BZBUFFER);
+                       buffer[nBuf]=0;
+                       x=0;
+               }
+
+               /* Build a string from buffer contents */
+
+               output[y]=buffer[x];
+
+               if (output[y]=='\n' || output[y]==0 || y==(int)length-1)
+               {
+                       output[y+1]=0;
+                       done=1;
+                       y=0;
+               }
+
+               else
+                       y++;
+               x++;
+
+       } while (done==0);
+
+       if (output[0]==0)
+               opened=0;
+
+       return (output);
+}
 
 int LoadSDF_BZ(char *name)
 {
@@ -1083,10 +1638,10 @@ int LoadSDF_BZ(char *name)
           maximum and minimum elevations, and quadrangle limits are
           stored in the first available dem[] structure. */
 
-       int x, y, data, indx, minlat, minlon, maxlat, maxlon;
-       char found, free_slot=0, sdf_file[255], path_plus_name[255];
-       FILE *fd;
-       BZFILE *bzfd;
+       int     x, y, data, indx, minlat, minlon, maxlat, maxlon;
+       char    found, free_slot=0, sdf_file[255], path_plus_name[255];
+       FILE    *fd;
+       BZFILE  *bzfd;
 
        for (x=0; name[x]!='.' && name[x]!=0 && x<247; x++)
                sdf_file[x]=name[x];
@@ -1111,11 +1666,8 @@ int LoadSDF_BZ(char *name)
 
        for (indx=0, found=0; indx<MAXSLOTS && found==0; indx++)
        {
-               if (minlat!=0 && minlon!=0)
-               {
-                       if (minlat==dem[indx].min_north && minlon==dem[indx].min_west && maxlat==dem[indx].max_north && maxlon==dem[indx].max_west)
-                               found=1;
-               }
+               if (minlat==dem[indx].min_north && minlon==dem[indx].min_west && maxlat==dem[indx].max_north && maxlon==dem[indx].max_west)
+                       found=1;
        }
 
        /* Is room available to load it? */
@@ -1123,20 +1675,33 @@ int LoadSDF_BZ(char *name)
        if (found==0)
        {       
                for (indx=0, free_slot=0; indx<MAXSLOTS && free_slot==0; indx++)
-                       if (dem[indx].max_north==0 && dem[indx].max_west==0)
+                       if (dem[indx].max_north==-90)
                                free_slot=1;
        }
 
        indx--;
 
-       if (free_slot && found==0 && indx>=0 && indx<MAXSLOTS && minlat!=0 && minlon!=0)
+       if (free_slot && found==0 && indx>=0 && indx<MAXSLOTS)
        {
-               strncpy(path_plus_name,sdf_path,255);
-               strncat(path_plus_name,sdf_file,255);
+               /* Search for SDF file in current working directory first */
+
+               strncpy(path_plus_name,sdf_file,255);
 
                fd=fopen(path_plus_name,"rb");
                bzfd=BZ2_bzReadOpen(&bzerror,fd,0,0,NULL,0);
 
+               if (fd==NULL || bzerror!=BZ_OK)
+               {
+                       /* Next, try loading SDF file from path specified
+                          in $HOME/.splat_path file or by -d argument */
+
+                       strncpy(path_plus_name,sdf_path,255);
+                       strncat(path_plus_name,sdf_file,255);
+
+                       fd=fopen(path_plus_name,"rb");
+                       bzfd=BZ2_bzReadOpen(&bzerror,fd,0,0,NULL,0);
+               }
+
                if (fd!=NULL && bzerror==BZ_OK)
                {
                        fprintf(stdout,"Loading \"%s\" into slot %d...",path_plus_name,indx+1);
@@ -1151,65 +1716,83 @@ int LoadSDF_BZ(char *name)
                                for (y=0; y<1200; y++)
                                {
                                        sscanf(BZfgets(bzfd,20),"%d",&data);
+
                                        dem[indx].data[x][y]=data;
 
                                        if (data>dem[indx].max_el)
                                                dem[indx].max_el=data;
 
-                                       if (dem[indx].min_el==0)
+                                       if (data<dem[indx].min_el)
                                                dem[indx].min_el=data;
-                                       else
-                                       {
-                                                if (data<dem[indx].min_el)
-                                                       dem[indx].min_el=data;
-                                       }
                                }
 
                        fclose(fd);
 
                        BZ2_bzReadClose(&bzerror,bzfd);
 
-                       if (min_elevation==0)
+                       if (dem[indx].min_el<min_elevation)
                                min_elevation=dem[indx].min_el;
-
-                       else
-                       {
-                               if (dem[indx].min_el<min_elevation)
-                                       min_elevation=dem[indx].min_el;
-                       }
        
                        if (dem[indx].max_el>max_elevation)
                                max_elevation=dem[indx].max_el;
 
-                       if (dem[indx].max_north>max_north)
+                       if (max_north==-90)
                                max_north=dem[indx].max_north;
 
-                       if (dem[indx].max_west>max_west)
-                               max_west=dem[indx].max_west;
+                       else if (dem[indx].max_north>max_north)
+                               max_north=dem[indx].max_north;
+
+                       if (min_north==90)
+                               min_north=dem[indx].min_north;
 
-                       if (min_north==0)
+                       else if (dem[indx].min_north<min_north)
                                min_north=dem[indx].min_north;
+
+                       if (max_west==-1)
+                               max_west=dem[indx].max_west;
+
                        else
                        {
-                               if (dem[indx].min_north<min_north)
-                                       min_north=dem[indx].min_north;
+                               if (abs(dem[indx].max_west-max_west)<180)
+                               {
+                                       if (dem[indx].max_west>max_west)
+                                               max_west=dem[indx].max_west;
+                               }
+
+                               else
+                               {
+                                       if (dem[indx].max_west<max_west)
+                                               max_west=dem[indx].max_west;
+                               }
                        }
 
-                       if (min_west==0)
+                       if (min_west==360)
                                min_west=dem[indx].min_west;
+
                        else
                        {
-                               if (dem[indx].min_west<min_west)
-                                       min_west=dem[indx].min_west;
+                               if (abs(dem[indx].min_west-min_west)<180)
+                               {
+                                       if (dem[indx].min_west<min_west)
+                                               min_west=dem[indx].min_west;
+                               }
+
+                               else
+                               {
+                                       if (dem[indx].min_west>min_west)
+                                               min_west=dem[indx].min_west;
+                               }
                        }
 
                        fprintf(stdout," Done!\n");
                        fflush(stdout);
                        return 1;
                }
+
                else
                        return -1;
        }
+
        else
                return 0;
 }
@@ -1225,9 +1808,9 @@ char LoadSDF(char *name)
           exists for the region requested, and that the region
           requested must be entirely over water. */
 
-       int x, y, indx, minlat, minlon, maxlat, maxlon;
-       char found, free_slot=0;
-       int  return_value=-1;
+       int     x, y, indx, minlat, minlon, maxlat, maxlon;
+       char    found, free_slot=0;
+       int     return_value=-1;
 
        /* Try to load an uncompressed SDF first. */
 
@@ -1250,11 +1833,8 @@ char LoadSDF(char *name)
 
                for (indx=0, found=0; indx<MAXSLOTS && found==0; indx++)
                {
-                       if (minlat!=0 && minlon!=0)
-                       {
-                               if (minlat==dem[indx].min_north && minlon==dem[indx].min_west && maxlat==dem[indx].max_north && maxlon==dem[indx].max_west)
-                                       found=1;
-                       }
+                       if (minlat==dem[indx].min_north && minlon==dem[indx].min_west && maxlat==dem[indx].max_north && maxlon==dem[indx].max_west)
+                               found=1;
                }
 
                /* Is room available to load it? */
@@ -1262,13 +1842,13 @@ char LoadSDF(char *name)
                if (found==0)
                {       
                        for (indx=0, free_slot=0; indx<MAXSLOTS && free_slot==0; indx++)
-                               if (dem[indx].max_north==0 && dem[indx].max_west==0)
+                               if (dem[indx].max_north==-90)
                                        free_slot=1;
                }
 
                indx--;
 
-               if (free_slot && found==0 && indx>=0 && indx<MAXSLOTS && minlat!=0 && minlon!=0)
+               if (free_slot && found==0 && indx>=0 && indx<MAXSLOTS)
                {
                        fprintf(stdout,"Region  \"%s\" assumed as sea-level into slot %d...",name,indx+1);
                        fflush(stdout);
@@ -1278,6 +1858,8 @@ char LoadSDF(char *name)
                        dem[indx].min_west=minlon;
                        dem[indx].max_north=maxlat;
 
+                       /* Fill DEM with sea-level topography */
+
                        for (x=0; x<1200; x++)
                                for (y=0; y<1200; y++)
                                {
@@ -1293,26 +1875,52 @@ char LoadSDF(char *name)
                        if (dem[indx].max_el>max_elevation)
                                max_elevation=dem[indx].max_el;
 
-                       if (dem[indx].max_north>max_north)
+                       if (max_north==-90)
                                max_north=dem[indx].max_north;
 
-                       if (dem[indx].max_west>max_west)
-                               max_west=dem[indx].max_west;
+                       else if (dem[indx].max_north>max_north)
+                               max_north=dem[indx].max_north;
+
+                       if (min_north==90)
+                               min_north=dem[indx].min_north;
 
-                       if (min_north==0)
+                       else if (dem[indx].min_north<min_north)
                                min_north=dem[indx].min_north;
+
+                       if (max_west==-1)
+                               max_west=dem[indx].max_west;
+
                        else
                        {
-                               if (dem[indx].min_north<min_north)
-                                       min_north=dem[indx].min_north;
+                               if (abs(dem[indx].max_west-max_west)<180)
+                               {
+                                       if (dem[indx].max_west>max_west)
+                                               max_west=dem[indx].max_west;
+                               }
+
+                               else
+                               {
+                                       if (dem[indx].max_west<max_west)
+                                               max_west=dem[indx].max_west;
+                               }
                        }
 
-                       if (min_west==0)
+                       if (min_west==360)
                                min_west=dem[indx].min_west;
+
                        else
                        {
-                               if (dem[indx].min_west<min_west)
-                                       min_west=dem[indx].min_west;
+                               if (abs(dem[indx].min_west-min_west)<180)
+                               {
+                                       if (dem[indx].min_west<min_west)
+                                               min_west=dem[indx].min_west;
+                               }
+
+                               else
+                               {
+                                       if (dem[indx].min_west>min_west)
+                                               min_west=dem[indx].min_west;
+                               }
                        }
 
                        fprintf(stdout," Done!\n");
@@ -1331,10 +1939,10 @@ void LoadCities(char *filename)
           the locations and names of the cities and site locations
           read on topographic maps generated by SPLAT! */
 
-       int x, y, z;
-       char input[80], str[3][80];
-       struct site city_site;
-       FILE *fd=NULL;
+       int     x, y, z;
+       char    input[80], str[3][80];
+       struct  site city_site;
+       FILE    *fd=NULL;
 
        fd=fopen(filename,"r");
 
@@ -1370,15 +1978,155 @@ void LoadCities(char *filename)
                        city_site.lon=ReadBearing(str[2]);
                        city_site.alt=0.0;
 
-                       PlaceMarker(city_site);
+                       PlaceMarker(city_site);
+
+                       fgets(input,78,fd);
+               }
+
+               fclose(fd);
+               fprintf(stdout,"Done!\n");
+               fflush(stdout);
+       }
+
+       else
+               fprintf(stderr,"*** ERROR: \"%s\": not found!\n",filename);
+}
+
+void LoadUDT(char *filename)
+{
+       /* This function reads a file containing User-Defined Terrain
+          features for their addition to the digital elevation model
+          data used by SPLAT!.  Elevations in the UDT file are evaluated
+          and then copied into a temporary file under /tmp.  Then the
+          contents of the temp file are scanned, and if found to be unique,
+          are added to the ground elevations described by the digital
+          elevation data already loaded into memory. */
+
+       int     i, x, y, z, fd=0;
+       char    input[80], str[3][80], tempname[15], *pointer=NULL;
+       double  latitude, longitude, height, templat, templon,
+               tempheight, one_pixel;
+       FILE    *fd1=NULL, *fd2=NULL;
+
+       strcpy(tempname,"/tmp/XXXXXX\0");
+       one_pixel=1.0/1200.0;
+
+       fd1=fopen(filename,"r");
+
+       if (fd1!=NULL)
+       {
+               fd=mkstemp(tempname);
+               fd2=fopen(tempname,"w");
+
+               fgets(input,78,fd1);
+
+               pointer=strchr(input,';');
+
+               if (pointer!=NULL)
+                       *pointer=0;
+
+               fprintf(stdout,"Reading \"%s\"... ",filename);
+               fflush(stdout);
+
+               while (feof(fd1)==0)
+               {
+                       /* Parse line for latitude, longitude, height */
+
+                       for (x=0, y=0, z=0; x<78 && input[x]!=0 && z<3; x++)
+                       {
+                               if (input[x]!=',' && y<78)
+                               {
+                                       str[z][y]=input[x];
+                                       y++;
+                               }
+
+                               else
+                               {
+                                       str[z][y]=0;
+                                       z++;
+                                       y=0;
+                               }
+                       }
+
+                       latitude=ReadBearing(str[0]);
+                       longitude=ReadBearing(str[1]);
+
+                       /* Remove <CR> and/or <LF> from antenna height string */
+
+                       for (i=0; str[2][i]!=13 && str[2][i]!=10 && str[2][i]!=0; i++);
+
+                       str[2][i]=0;
+
+                       /* The terrain feature may be expressed in either
+                          feet or meters.  If the letter 'M' or 'm' is
+                          discovered in the string, then this is an
+                          indication that the value given is expressed
+                          in meters.  Otherwise the height is interpreted
+                          as being expressed in feet.  */
+
+                       for (i=0; str[2][i]!='M' && str[2][i]!='m' && str[2][i]!=0 && i<48; i++);
+
+                       if (str[2][i]=='M' || str[2][i]=='m')
+                       {
+                               str[2][i]=0;
+                               height=rint(atof(str[2]));
+                       }
+
+                       else
+                       {
+                               str[2][i]=0;
+                               height=rint(3.28084*atof(str[2]));
+                       }
+
+                       if (height>0.0)
+                               fprintf(fd2,"%f, %f, %f\n",latitude, longitude, height);
+
+                       fgets(input,78,fd1);
+
+                       pointer=strchr(input,';');
+
+                       if (pointer!=NULL)
+                               *pointer=0;
+               }
+
+               fclose(fd1);
+               fclose(fd2);
+               close(fd);
+
+               fprintf(stdout,"Done!\n");
+               fflush(stdout);
+
+               fd1=fopen(tempname,"r");
+               fd2=fopen(tempname,"r");
+
+               fscanf(fd1,"%lf, %lf, %lf", &latitude, &longitude, &height);
+
+               for (y=0; feof(fd1)==0; y++)
+               {
+                       rewind(fd2);
+
+                       fscanf(fd2,"%lf, %lf, %lf", &templat, &templon, &tempheight);
+
+                       for (x=0, z=0; feof(fd2)==0; x++)
+                       {
+                               if (x>y)
+                                       if (fabs(latitude-templat)<=one_pixel && fabs(longitude-templon)<=one_pixel)
+                                               z=1;
+
+                               fscanf(fd2,"%lf, %lf, %lf", &templat, &templon, &tempheight);
+                       }
+
+                       if (z==0)
+                               AddElevation(latitude, longitude, height);
 
-                       fgets(input,78,fd);
+                       fscanf(fd1,"%lf, %lf, %lf", &latitude, &longitude, &height);
                }
 
-               fclose(fd);
-               fprintf(stdout,"Done!\n");
-               fflush(stdout);
+               fclose(fd1);
+               fclose(fd2);
+               unlink(tempname);
        }
+
        else
                fprintf(stderr,"*** ERROR: \"%s\": not found!\n",filename);
 }
@@ -1391,11 +2139,11 @@ void LoadBoundaries(char *filename)
           the coordinates that describe the boundaries of cities,
           counties, and states. */
 
-       int x;
-       double lat0, lon0, lat1, lon1;
-       char string[80];
-       struct site source, destination;
-       FILE *fd=NULL;
+       int     x;
+       double  lat0, lon0, lat1, lon1;
+       char    string[80];
+       struct  site source, destination;
+       FILE    *fd=NULL;
 
        fd=fopen(filename,"r");
 
@@ -1415,7 +2163,7 @@ void LoadBoundaries(char *filename)
                        do
                        {
                                sscanf(string,"%lf %lf", &lon1, &lat1);
-                       
+
                                lon0=fabs(lon0);
                                lon1=fabs(lon1);
 
@@ -1445,6 +2193,7 @@ void LoadBoundaries(char *filename)
                fprintf(stdout,"Done!\n");
                fflush(stdout);
        }
+
        else
                fprintf(stderr,"*** ERROR: \"%s\": not found!\n",filename);
 }
@@ -1457,12 +2206,12 @@ void ReadLRParm(char *txsite_filename)
           is not found, then the file "splat.lrp" is read from the
           current working directory.  Failure to load this file will
           result in the default parameters hard coded into this
-          being used and written to "splat.lrp". */
+          function to be used and written to "splat.lrp". */
 
-       double din;
-       char filename[255], lookup[256], string[80];
-       int iin, ok=0, x;
-       FILE *fd=NULL, *outfile=NULL;
+       double  din;
+       char    filename[255], string[80], *pointer=NULL;
+       int     iin, ok=0, x;
+       FILE    *fd=NULL, *outfile=NULL;
 
        /* Default parameters in case things go bad */
 
@@ -1487,20 +2236,6 @@ void ReadLRParm(char *txsite_filename)
        filename[x+3]='p';
        filename[x+4]=0;
 
-       /* Small lookup table to parse file, pass
-          numeric data, and ignore comments. */
-
-       for (x=0; x<=255; x++)
-               lookup[x]=0;
-
-       /* Valid characters */
-
-       for (x=48; x<=57; x++)
-               lookup[x]=x;
-
-       lookup[32]=32;
-       lookup[46]='.';
-
        fd=fopen(filename,"r");
 
        if (fd==NULL)
@@ -1515,10 +2250,10 @@ void ReadLRParm(char *txsite_filename)
        {
                fgets(string,80,fd);
 
-               for (x=0; lookup[(int)string[x]] && x<20; x++)
-                       string[x]=lookup[(int)string[x]];
+               pointer=strchr(string,';');
 
-               string[x]=0;
+               if (pointer!=NULL)
+                       *pointer=0;
 
                ok=sscanf(string,"%lf", &din);
 
@@ -1528,10 +2263,10 @@ void ReadLRParm(char *txsite_filename)
 
                        fgets(string,80,fd);
 
-                       for (x=0; lookup[(int)string[x]] && x<20; x++)
-                               string[x]=lookup[(int)string[x]];
+                       pointer=strchr(string,';');
 
-                       string[x]=0;
+                       if (pointer!=NULL)
+                               *pointer=0;
 
                        ok=sscanf(string,"%lf", &din);
                }
@@ -1542,10 +2277,10 @@ void ReadLRParm(char *txsite_filename)
 
                        fgets(string,80,fd);
 
-                       for (x=0; lookup[(int)string[x]] && x<20; x++)
-                               string[x]=lookup[(int)string[x]];
+                       pointer=strchr(string,';');
 
-                       string[x]=0;
+                       if (pointer!=NULL)
+                               *pointer=0;
 
                        ok=sscanf(string,"%lf", &din);
                }
@@ -1556,10 +2291,10 @@ void ReadLRParm(char *txsite_filename)
 
                        fgets(string,80,fd);
 
-                       for (x=0; lookup[(int)string[x]] && x<20; x++)
-                               string[x]=lookup[(int)string[x]];
+                       pointer=strchr(string,';');
 
-                       string[x]=0;
+                       if (pointer!=NULL)
+                               *pointer=0;
 
                        ok=sscanf(string,"%lf", &din);
                }
@@ -1570,10 +2305,10 @@ void ReadLRParm(char *txsite_filename)
 
                        fgets(string,80,fd);
 
-                       for (x=0; lookup[(int)string[x]] && x<20; x++)
-                               string[x]=lookup[(int)string[x]];
+                       pointer=strchr(string,';');
 
-                       string[x]=0;
+                       if (pointer!=NULL)
+                               *pointer=0;
 
                        ok=sscanf(string,"%d", &iin);
                }
@@ -1584,10 +2319,10 @@ void ReadLRParm(char *txsite_filename)
 
                        fgets(string,80,fd);
 
-                       for (x=0; lookup[(int)string[x]] && x<20; x++)
-                               string[x]=lookup[(int)string[x]];
+                       pointer=strchr(string,';');
 
-                       string[x]=0;
+                       if (pointer!=NULL)
+                               *pointer=0;
 
                        ok=sscanf(string,"%d", &iin);
                }
@@ -1598,10 +2333,10 @@ void ReadLRParm(char *txsite_filename)
 
                        fgets(string,80,fd);
 
-                       for (x=0; lookup[(int)string[x]] && x<20; x++)
-                               string[x]=lookup[(int)string[x]];
+                       pointer=strchr(string,';');
 
-                       string[x]=0;
+                       if (pointer!=NULL)
+                               *pointer=0;
 
                        ok=sscanf(string,"%lf", &din);
                }
@@ -1612,18 +2347,21 @@ void ReadLRParm(char *txsite_filename)
 
                        fgets(string,80,fd);
 
-                       for (x=0; lookup[(int)string[x]] && x<20; x++)
-                               string[x]=lookup[(int)string[x]];
+                       pointer=strchr(string,';');
 
-                       string[x]=0;
+                       if (pointer!=NULL)
+                               *pointer=0;
 
                        ok=sscanf(string,"%lf", &din);
                }
 
+               fclose(fd);
+
                if (ok)
+               {
                        LR.rel=din;
-
-               fclose(fd);
+                       LoadPAT(filename);
+               }
        } 
 
        if (fd==NULL)
@@ -1634,21 +2372,13 @@ void ReadLRParm(char *txsite_filename)
                outfile=fopen("splat.lrp","w");
 
                fprintf(outfile,"%.3f\t; Earth Dielectric Constant (Relative permittivity)\n",LR.eps_dielect);
-
                fprintf(outfile,"%.3f\t; Earth Conductivity (Siemens per meter)\n", LR.sgm_conductivity);
-
                fprintf(outfile,"%.3f\t; Atmospheric Bending Constant (N-Units)\n",LR.eno_ns_surfref);
-
                fprintf(outfile,"%.3f\t; Frequency in MHz (20 MHz to 20 GHz)\n", LR.frq_mhz);
-
                fprintf(outfile,"%d\t; Radio Climate\n",LR.radio_climate);
-
                fprintf(outfile,"%d\t; Polarization (0 = Horizontal, 1 = Vertical)\n", LR.pol);
-
                fprintf(outfile,"%.2f\t; Fraction of situations\n",LR.conf);
-
                fprintf(outfile, "%.2f\t; Fraction of time\n",LR.rel);
-
                fprintf(outfile,"\nPlease consult SPLAT! documentation for the meaning and use of this data.\n");
 
                fclose(outfile);
@@ -1660,98 +2390,6 @@ void ReadLRParm(char *txsite_filename)
                fprintf(stderr,"Longley-Rice default parameters have been assumed for this analysis.\n");
 }
 
-struct site los(struct site source, struct site destination)
-{
-       /* This function determines whether a line-of-sight path
-          unobstructed by terrain exists between source (transmitter)
-          and destination (receiver) based on the geographical
-          locations of the two sites, their respective antenna
-          heights above ground, and the terrain between them.
-          A site structure is returned upon completion.  If the
-          first character of site.name is ' ', then a clear path
-          exists between source and destination.  If the first
-          character is '*', then an obstruction exists, and the
-          site.lat and site.lon elements of the structure provide
-          the geographical location of the obstruction. */
-          
-       int x;
-       char block;
-       struct site test, blockage;
-       register double distance, tx_alt, rx_alt,
-                cos_xmtr_angle, cos_test_angle, test_alt;
-
-       ReadPath(source,destination);
-
-       distance=5280.0*Distance(source,destination);
-       tx_alt=earthradius+source.alt+GetElevation(source);
-       rx_alt=earthradius+destination.alt+GetElevation(destination);
-
-       /* Elevation angle of the xmtr (source) as seen by the rcvr */
-
-       cos_xmtr_angle=((rx_alt*rx_alt)+(distance*distance)-(tx_alt*tx_alt))/(2.0*rx_alt*distance);
-
-       /* Determine the elevation angle of each discrete location
-          along the path between the receiver and transmitter.
-
-          Since obstructions are more likely due to terrain effects
-          closest to the receiver rather than farther away, we start
-          looking for potential obstructions from the receiver's
-          location, and work our way towards the transmitter.
-          This loop is broken when the first obstruction is
-          detected.  If we can travel all the way to the transmitter
-          without detecting an obstruction, then we have a clear
-          unobstructed path between transmitter and receiver. */
-
-       for (x=path.length-1, block=0; x>0 && block==0; x--)
-       {
-               /* Build a structure for each test
-                  point along the path to be surveyed. */
-
-               test.lat=path.lat[x];
-               test.lon=path.lon[x];
-
-               /* Measure the distance between the
-                  test point and the receiver locations */
-
-               distance=5280.0*Distance(test,destination);
-               test_alt=earthradius+path.elevation[x];
-
-               /* Determine the cosine of the elevation of the test
-                  point as seen from the location of the receiver */
-
-               cos_test_angle=((rx_alt*rx_alt)+(distance*distance)-(test_alt*test_alt))/(2.0*rx_alt*distance);
-
-               /* If the elevation angle to the test point (as seen from
-                  the receiver) is greater than the elevation angle to the
-                  transmitter (as seen by the receiver), then we have a
-                  path obstructed by terrain.  Note: Since we're comparing
-                  the cosines of these angles rather than the angles
-                  themselves (eliminating the call to acos() saves
-                  considerable time), the following "if" statement is
-                  reversed from what it would normally be if the angles
-                  were compared. */
-
-               if (cos_xmtr_angle>cos_test_angle)
-               {
-                       block=1;
-                       blockage.lat=path.lat[x];
-                       blockage.lon=path.lon[x];
-                       blockage.alt=path.elevation[x];
-                       blockage.name[0]='*';
-               }
-       }
-
-       if (block==0)
-       {
-               blockage.lat=0.0;
-               blockage.lon=0.0;
-               blockage.alt=0.0;
-               blockage.name[0]=' ';
-       }
-
-       return blockage;
-}
-
 void PlotPath(struct site source, struct site destination, char mask_value)
 {
        /* This function analyzes the path between the source and
@@ -1794,7 +2432,7 @@ void PlotPath(struct site source, struct site destination, char mask_value)
                                cos_test_angle=((rx_alt*rx_alt)+(distance*distance)-(test_alt*test_alt))/(2.0*rx_alt*distance);
 
                                /* Compare these two angles to determine if
-                                  a blockage exists.  Since we're comparing
+                                  an obstruction exists.  Since we're comparing
                                   the cosines of these angles rather than
                                   the angles themselves, the following "if"
                                   statement is reversed from what it would
@@ -1810,39 +2448,145 @@ void PlotPath(struct site source, struct site destination, char mask_value)
        }
 }
 
-void PlotLRPath(struct site source, struct site destination)
+void PlotLRPath(struct site source, struct site destination, FILE *fd)
 {
-       /* This function plots the RF signal path loss
-          between source and destination points based
-          on the Longley-Rice propagation model. */
-
-       char strmode[100];
-       int x, y, errnum;
-       double loss;
+       /* This function plots the RF path loss between source and
+          destination points based on the Longley-Rice propagation
+          model, taking into account antenna pattern data, if available. */
+
+       char    block=0, strmode[100];
+       int     x, y, errnum;
+       double  loss, azimuth, pattern=0.0, 
+               source_alt, dest_alt, source_alt2, dest_alt2,
+               cos_xmtr_angle, cos_test_angle=0.0, test_alt,
+               elevation, distance=0.0, four_thirds_earth;
+       struct  site temp;
 
        ReadPath(source,destination);
-       elev_l[1]=0.04*METERS_PER_MILE;
+
+       four_thirds_earth=EARTHRADIUS*(4.0/3.0);
+
+       /* Copy elevations along path into the elev_l[] array. */
 
        for (x=0; x<path.length; x++)
-               elev_l[x+2]=path.elevation[x]*METERS_PER_FOOT;  
-        
-       for (y=0; y<path.length; y++)
+               elev_l[x+2]=path.elevation[x]*METERS_PER_FOOT;
+
+       /* Since the only energy the Longley-Rice model considers
+          reaching the destination is based on what is scattered
+          or deflected from the first obstruction along the path,
+          we first need to find the location and elevation angle
+          of that first obstruction (if it exists).  This is done
+          using a 4/3rds Earth radius to match the model used by
+          Longley-Rice.  This information is required for properly
+          integrating the antenna's elevation pattern into the
+          calculation for overall path loss.  (Using path.length-1
+          below avoids a Longley-Rice model error from occuring at
+          the destination point.) */
+
+       for (y=2; (y<(path.length-1) && path.distance[y]<=max_range); y++)
        {
-               /* Test this point only if it
-                  has not already been tested. */
+               /* Process this point only if it
+                  has not already been processed. */
 
-               if (GetMask(path.lat[y],path.lon[y])==0 && 0.04*y<=max_range)
+               if (GetMask(path.lat[y],path.lon[y])==0)
                {
-                       elev_l[0]=y+1;
+                       distance=5280.0*path.distance[y];
+                       source_alt=four_thirds_earth+source.alt+path.elevation[0];
+                       dest_alt=four_thirds_earth+destination.alt+path.elevation[y];
+                       dest_alt2=dest_alt*dest_alt;
+                       source_alt2=source_alt*source_alt;
+
+                       /* Calculate the cosine of the elevation of
+                          the receiver as seen by the transmitter. */
+
+                       cos_xmtr_angle=((source_alt2)+(distance*distance)-(dest_alt2))/(2.0*source_alt*distance);
+
+                       if (got_elevation_pattern || fd!=NULL)
+                       {
+                               /* If no antenna elevation pattern is available, and
+                                  no output file is designated, the following code
+                                  that determines the elevation angle to the first
+                                  obstruction along the path is bypassed. */
+
+                               for (x=2, block=0; (x<y && block==0); x++)
+                               {
+                                       distance=5280.0*path.distance[x];
+                                       test_alt=four_thirds_earth+path.elevation[x];
+
+                                       /* Calculate the cosine of the elevation
+                                          angle of the terrain (test point)
+                                          as seen by the transmitter. */
+
+                                       cos_test_angle=((source_alt2)+(distance*distance)-(test_alt*test_alt))/(2.0*source_alt*distance);
+
+                                       /* Compare these two angles to determine if
+                                          an obstruction exists.  Since we're comparing
+                                          the cosines of these angles rather than
+                                          the angles themselves, the sense of the
+                                          following "if" statement is reversed from
+                                          what it would be if the angles themselves
+                                          were compared. */
+
+                                       if (cos_xmtr_angle>cos_test_angle)
+                                               block=1;
+                               }
+
+                               /* At this point, we have the elevation angle
+                                  to the first obstruction (if it exists). */
+                       }
+
+                       /* Determine attenuation for each point along the
+                          path using Longley-Rice's point_to_point mode
+                          starting at y=2 (number_of_points = 1), the
+                          shortest distance terrain can play a role in
+                          path loss. */
+                       elev_l[0]=y-1;  /* (number of points - 1) */
+
+                       /* Distance between elevation samples */
+                       elev_l[1]=METERS_PER_MILE*(path.distance[y]-path.distance[y-1]);
 
                        point_to_point(elev_l,source.alt*METERS_PER_FOOT, 
-                       destination.alt*METERS_PER_FOOT,
-                       LR.eps_dielect, LR.sgm_conductivity, LR.eno_ns_surfref,
-                       LR.frq_mhz, LR.radio_climate, LR.pol, LR.conf, LR.rel,
-                       loss, strmode, errnum);
+                       destination.alt*METERS_PER_FOOT, LR.eps_dielect,
+                       LR.sgm_conductivity, LR.eno_ns_surfref, LR.frq_mhz,
+                       LR.radio_climate, LR.pol, LR.conf, LR.rel, loss,
+                       strmode, errnum);
+
+                       if (block)
+                               elevation=((acos(cos_test_angle))/deg2rad)-90.0;
+
+                       else
+                               elevation=((acos(cos_xmtr_angle))/deg2rad)-90.0;
+
+                       temp.lat=path.lat[y];
+                       temp.lon=path.lon[y];
 
-                       /* Note: PASS BY REFERENCE ... loss and errnum are pass
-                       by reference, only used in this file by this function */
+                       azimuth=(Azimuth(source,temp));
+
+                       if (fd!=NULL)
+                       {
+                               /* Write path loss data to output file */
+
+                               fprintf(fd,"%.7f, %.7f, %.3f, %.3f, %.2f\n",path.lat[y], path.lon[y], azimuth, elevation, loss);
+                       }
+
+                       /* Integrate the antenna's radiation
+                          pattern into the overall path loss. */
+
+                       x=(int)rint(10.0*(10.0-elevation));
+
+                       if (x>=0 && x<=1000)
+                       {
+                               azimuth=rint(azimuth);
+
+                               pattern=(double)LR.antenna_pattern[(int)azimuth][x];
+
+                               if (pattern!=0.0)
+                               {
+                                       pattern=20.0*log10(pattern);
+                                       loss-=pattern;
+                               }
+                       }
 
                        if (loss>225.0)
                                loss=225.0;
@@ -1857,7 +2601,7 @@ void PlotLRPath(struct site source, struct site destination)
                        OrMask(path.lat[y],path.lon[y],((unsigned char)(loss))<<3);
                }
 
-               else if (GetMask(path.lat[y],path.lon[y])==0 && 0.04*y>max_range)
+               else if (GetMask(path.lat[y],path.lon[y])==0 && path.distance[y]>max_range)
                        OrMask(path.lat[y],path.lon[y],1);
        }
 }
@@ -1873,7 +2617,7 @@ void PlotCoverage(struct site source, double altitude)
           of a topographic map when the WritePPM() function
           is later invoked. */
 
-       double lat, lon, one_pixel;
+       float lat, lon, one_pixel;
        static unsigned char mask_value;
        int z, count;
        struct site edge;
@@ -1893,16 +2637,19 @@ void PlotCoverage(struct site source, double altitude)
 
        count=0;        
 
-       fprintf(stdout,"\nComputing line-of-sight coverage of %s with an RX antenna\nat %.2f feet AGL:\n\n 0%c to  25%c ",source.name,altitude,37,37);
+       fprintf(stdout,"\nComputing line-of-sight coverage of %s with an RX antenna\nat %.2f %s AGL:\n\n 0%c to  25%c ",source.name,metric?altitude*METERS_PER_FOOT:altitude,metric?"meters":"feet",37,37);
        fflush(stdout);
 
        /* 18.75=1200 pixels/degree divided by 64 loops
           per progress indicator symbol (.oOo) printed. */
 
-       z=(int)(18.75*(max_west-min_west));
+       z=(int)(18.75*ReduceAngle(max_west-min_west));
 
-       for (lon=min_west, x=0; lon<=max_west; lon+=one_pixel)
+       for (lon=min_west, x=0; (LonDiff(lon,max_west)<=0.0); lon+=one_pixel)
        {
+               if (lon>=360.0)
+                       lon-=360.0;
+
                edge.lat=max_north;
                edge.lon=lon;
                edge.alt=altitude;
@@ -1955,10 +2702,13 @@ void PlotCoverage(struct site source, double altitude)
        fprintf(stdout,"\n50%c to  75%c ",37,37);
        fflush(stdout);
 
-       z=(int)(18.75*(max_west-min_west));
+       z=(int)(18.75*ReduceAngle(max_west-min_west));
 
-       for (lon=min_west, x=0; lon<=max_west; lon+=one_pixel)
+       for (lon=min_west, x=0; (LonDiff(lon,max_west)<=0.0); lon+=one_pixel)
        {
+               if (lon>=360.0)
+                       lon-=360.0;
+
                edge.lat=min_north;
                edge.lon=lon;
                edge.alt=altitude;
@@ -2027,7 +2777,7 @@ void PlotCoverage(struct site source, double altitude)
        }
 }
 
-void PlotLRMap(struct site source, double altitude)
+void PlotLRMap(struct site source, double altitude, char *plo_filename)
 {
        /* This function performs a 360 degree sweep around the
           transmitter site (source location), and plots the
@@ -2040,8 +2790,9 @@ void PlotLRMap(struct site source, double altitude)
 
        int z, count;
        struct site edge;
-       double lat, lon, one_pixel;
+       float lat, lon, one_pixel;
        unsigned char symbol[4], x;
+       FILE *fd=NULL;
 
        one_pixel=1.0/1200.0;
 
@@ -2053,21 +2804,35 @@ void PlotLRMap(struct site source, double altitude)
        count=0;
 
        fprintf(stdout,"\nComputing Longley-Rice coverage of %s ", source.name);
-       fprintf(stdout,"out to a radius\nof %.2f miles with an RX antenna at %.2f feet AGL:\n\n 0%c to  25%c ",max_range,altitude,37,37);
+
+       fprintf(stdout,"out to a radius\nof %.2f %s with an RX antenna at %.2f %s AGL:\n\n 0%c to  25%c ",metric?max_range*KM_PER_MILE:max_range,metric?"kilometers":"miles",metric?altitude*METERS_PER_FOOT:altitude,metric?"meters":"feet",37,37);
        fflush(stdout);
 
+       if (plo_filename[0]!=0)
+               fd=fopen(plo_filename,"wb");
+
+       if (fd!=NULL)
+       {
+               /* Write header information to output file */
+
+               fprintf(fd,"%d, %d\t; max_west, min_west\n%d, %d\t; max_north, min_north\n",max_west, min_west, max_north, min_north);
+       }
+
        /* 18.75=1200 pixels/degree divided by 64 loops
           per progress indicator symbol (.oOo) printed. */
 
-       z=(int)(18.75*(max_west-min_west));
+       z=(int)(18.75*ReduceAngle(max_west-min_west));
 
-       for (lon=min_west, x=0; lon<=max_west; lon+=one_pixel)
+       for (lon=min_west, x=0; (LonDiff(lon,max_west)<=0.0); lon+=one_pixel)
        {
+               if (lon>=360.0)
+                       lon-=360.0;
+
                edge.lat=max_north;
                edge.lon=lon;
                edge.alt=altitude;
 
-               PlotLRPath(source,edge);
+               PlotLRPath(source,edge,fd);
                count++;
 
                if (count==z) 
@@ -2095,7 +2860,7 @@ void PlotLRMap(struct site source, double altitude)
                edge.lon=min_west;
                edge.alt=altitude;
 
-               PlotLRPath(source,edge);
+               PlotLRPath(source,edge,fd);
                count++;
 
                if (count==z) 
@@ -2115,15 +2880,18 @@ void PlotLRMap(struct site source, double altitude)
        fprintf(stdout,"\n50%c to  75%c ",37,37);
        fflush(stdout);
 
-       z=(int)(18.75*(max_west-min_west));
+       z=(int)(18.75*ReduceAngle(max_west-min_west));
 
-       for (lon=min_west, x=0; lon<=max_west; lon+=one_pixel)
+       for (lon=min_west, x=0; (LonDiff(lon,max_west)<=0.0); lon+=one_pixel)
        {
+               if (lon>=360.0)
+                       lon-=360.0;
+
                edge.lat=min_north;
                edge.lon=lon;
                edge.alt=altitude;
 
-               PlotLRPath(source,edge);
+               PlotLRPath(source,edge,fd);
                count++;
 
                if (count==z)
@@ -2151,7 +2919,7 @@ void PlotLRMap(struct site source, double altitude)
                edge.lon=max_west;
                edge.alt=altitude;
 
-               PlotLRPath(source,edge);
+               PlotLRPath(source,edge,fd);
                count++;
 
                if (count==z)
@@ -2167,11 +2935,14 @@ void PlotLRMap(struct site source, double altitude)
                }
        }
 
+       if (fd!=NULL)
+               fclose(fd);
+
        fprintf(stdout,"\nDone!\n");
        fflush(stdout);
 }
 
-void WritePPM(char *filename)
+void WritePPM(char *filename, unsigned char geo)
 {
        /* This function generates a topographic map in Portable Pix Map
           (PPM) format based on logarithmically scaled topology data,
@@ -2180,32 +2951,54 @@ void WritePPM(char *filename)
           from its representation in dem[][] so that north points
           up and east points right in the image generated. */
 
-       int indx, x, x0, y0, minlat, minlon;
-       unsigned width, height, output;
+       char mapfile[255], geofile[255];
        unsigned char found, mask;
-       char mapfile[255];
-       double conversion, lat, lon, one_over_gamma, one_pixel;
+       unsigned width, height, output;
+       int indx, x, y, x0=0, y0=0, minlat, minlon;
+       float lat, lon, one_pixel, conversion, one_over_gamma;
        FILE *fd;
 
        one_pixel=1.0/1200.0;
        one_over_gamma=1.0/GAMMA;
        conversion=255.0/pow((double)(max_elevation-min_elevation),one_over_gamma);
 
-       width=1200*(max_west-min_west);
-       height=1200*(max_north-min_north);
+       width=(unsigned)(1200*ReduceAngle(max_west-min_west));
+       height=(unsigned)(1200*ReduceAngle(max_north-min_north));
 
        if (filename[0]==0)
                strncpy(mapfile, "map.ppm\0",8);
        else
        {
                for (x=0; filename[x]!='.' && filename[x]!=0 && x<250; x++)
+               {
                        mapfile[x]=filename[x];
+                       geofile[x]=filename[x];
+               }
 
                mapfile[x]='.';
+               geofile[x]='.';
                mapfile[x+1]='p';
+               geofile[x+1]='g';
                mapfile[x+2]='p';
+               geofile[x+2]='e';
                mapfile[x+3]='m';
+               geofile[x+3]='o';
                mapfile[x+4]=0;
+               geofile[x+4]=0;
+       }
+
+       if (geo)
+       {
+               fd=fopen(geofile,"wb");
+
+               fprintf(fd,"FILENAME\t%s\n",mapfile);
+               fprintf(fd,"#\t\tX\tY\tLong\t\tLat\n");
+               fprintf(fd,"TIEPOINT\t0\t0\t%d.000\t\t%d.000\n",(max_west<180?-max_west:360-max_west),max_north);
+               fprintf(fd,"TIEPOINT\t%u\t%u\t%d.000\t\t%d.000\n",width-1,height-1,(min_west<180?-min_west:360-min_west),min_north);
+               fprintf(fd,"IMAGESIZE\t%u\t%u\n",width,height);
+               fprintf(fd,"#\n# Auto Generated by SPLAT! v%s\n#\n",splat_version);
+
+               fclose(fd);
        }
 
        fd=fopen(mapfile,"wb");
@@ -2215,11 +3008,15 @@ void WritePPM(char *filename)
        fprintf(stdout,"\nWriting \"%s\" (%ux%u pixmap image)... ",mapfile,width,height);
        fflush(stdout);
 
-       for (lat=(double)max_north; lat>=(double)min_north; lat-=one_pixel)
+       for (y=0, lat=((double)max_north)-one_pixel; y<(int)height; y++, lat-=one_pixel)
        {
-               for (lon=(double)max_west; lon>=(double)min_west; lon-=one_pixel)
+               minlat=(int)floor(lat);
+
+               for (x=0, lon=((double)max_west)-one_pixel; x<(int)width; x++, lon-=one_pixel)
                {
-                       minlat=(int)floor(lat);
+                       if (lon<0.0)
+                               lon+=360.0;
+
                        minlon=(int)floor(lon);
 
                        for (indx=0, found=0; indx<MAXSLOTS && found==0;)
@@ -2227,10 +3024,11 @@ void WritePPM(char *filename)
                                        found=1;
                                else
                                        indx++;
+
                        if (found)
                        {
-                               x0=(int)((1199.0*(lat-floor(lat)))+0.5);
-                               y0=(int)((1199.0*(lon-floor(lon)))+0.5);
+                               x0=(int)(1199.0*(lat-floor(lat)));
+                               y0=(int)(1199.0*(lon-floor(lon)));
 
                                mask=dem[indx].mask[x0][y0];
 
@@ -2331,6 +3129,14 @@ void WritePPM(char *filename)
                                        }
                                }
                        }
+
+                       else
+                       {
+                               /* We should never get here, but if */
+                               /* we do, display the region as black */
+
+                               fprintf(fd,"%c%c%c",0,0,0);
+                       }
                }
        }
 
@@ -2339,7 +3145,7 @@ void WritePPM(char *filename)
        fflush(stdout);
 }
 
-void WritePPMLR(char *filename)
+void WritePPMLR(char *filename, unsigned char geo)
 {
        /* This function generates a topographic map in Portable Pix Map
           (PPM) format based on the content of flags held in the mask[][] 
@@ -2347,32 +3153,54 @@ void WritePPMLR(char *filename)
           90 degrees from its representation in dem[][] so that north
           points up and east points right in the image generated. */
 
-       int indx, x, t, t2, x0, y0, minlat, minlon;
+       char mapfile[255], geofile[255];
        unsigned width, height, output;
-       unsigned char found, mask;
-       char mapfile[255];
-       double conversion, lat, lon, one_over_gamma, one_pixel;
+       unsigned char found, mask, cityorcounty;
+       int indx, x, y, t, t2, x0, y0, minlat, minlon, loss;
+       float lat, lon, one_pixel, conversion, one_over_gamma;
        FILE *fd;
 
        one_pixel=1.0/1200.0;
        one_over_gamma=1.0/GAMMA;
        conversion=255.0/pow((double)(max_elevation-min_elevation),one_over_gamma);
 
-       width=1200*(max_west-min_west);
-       height=1200*(max_north-min_north);
+       width=(unsigned)(1200*ReduceAngle(max_west-min_west));
+       height=(unsigned)(1200*ReduceAngle(max_north-min_north));
 
        if (filename[0]==0)
                strncpy(mapfile, "map.ppm\0",8);
        else
        {
                for (x=0; filename[x]!='.' && filename[x]!=0 && x<250; x++)
+               {
                        mapfile[x]=filename[x];
+                       geofile[x]=filename[x];
+               }
 
                mapfile[x]='.';
+               geofile[x]='.';
                mapfile[x+1]='p';
+               geofile[x+1]='g';
                mapfile[x+2]='p';
+               geofile[x+2]='e';
                mapfile[x+3]='m';
+               geofile[x+3]='o';
                mapfile[x+4]=0;
+               geofile[x+4]=0;
+       }
+
+       if (geo)
+       {
+               fd=fopen(geofile,"wb");
+
+               fprintf(fd,"FILENAME\t%s\n",mapfile);
+               fprintf(fd,"#\t\tX\tY\tLong\t\tLat\n");
+               fprintf(fd,"TIEPOINT\t0\t0\t%d.000\t\t%d.000\n",(max_west<180?-max_west:360-max_west),max_north);
+               fprintf(fd,"TIEPOINT\t%u\t%u\t%d.000\t\t%.3f\n",width-1,height+29,(min_west<180?-min_west:360-min_west),(double)(min_north-0.025));
+               fprintf(fd,"IMAGESIZE\t%u\t%u\n",width,height+30);
+               fprintf(fd,"#\n# Auto Generated by SPLAT! v%s\n#\n",splat_version);
+
+               fclose(fd);
        }
 
        fd=fopen(mapfile,"wb");
@@ -2382,11 +3210,15 @@ void WritePPMLR(char *filename)
        fprintf(stdout,"\nWriting \"%s\" (%ux%u pixmap image)... ",mapfile,width,height+30);
        fflush(stdout);
 
-       for (lat=(double)max_north; lat>=(double)min_north; lat-=one_pixel)
+       for (y=0, lat=((double)max_north)-one_pixel; y<(int)height; y++, lat-=one_pixel)
        {
-               for (lon=(double)max_west; lon>=(double)min_west; lon-=one_pixel)
+               minlat=(int)floor(lat);
+
+               for (x=0, lon=((double)max_west)-one_pixel; x<(int)width; x++, lon-=one_pixel)
                {
-                       minlat=(int)floor(lat);
+                       if (lon<0.0)
+                               lon+=360.0;
+
                        minlon=(int)floor(lon);
 
                        for (indx=0, found=0; indx<MAXSLOTS && found==0;)
@@ -2396,150 +3228,144 @@ void WritePPMLR(char *filename)
                                        indx++;
                        if (found)
                        {
-                               x0=(int)((1199.0*(lat-floor(lat)))+0.5);
-                               y0=(int)((1199.0*(lon-floor(lon)))+0.5);
+                               x0=(int)(1199.0*(lat-floor(lat)));
+                               y0=(int)(1199.0*(lon-floor(lon)));
 
                                mask=dem[indx].mask[x0][y0];
+                               loss=70+(10*(int)((mask&248)>>3));
+                               cityorcounty=0;
 
                                if (mask&2)
                                {
                                        /* Text Labels - Black or Red */
-                                       if (mask&120)
+
+                                       if ((mask&120) && (loss<=90))
                                                fprintf(fd,"%c%c%c",0,0,0);
                                        else
                                                fprintf(fd,"%c%c%c",255,0,0);
+
+                                       cityorcounty=1;
                                }
 
                                else if (mask&4)
+                               {
                                        /* County Boundaries: Black */
-                                       fprintf(fd,"%c%c%c",0,0,0);
 
-                               else if (mask&1 && !((mask&248)==192))
-                               {
-                                       /* Outside Analysis Range */
-                                       /* Display Greyscale / Sea Level */
+                                       fprintf(fd,"%c%c%c",0,0,0);
 
-                                       if (dem[indx].data[x0][y0]==0)
-                                               fprintf(fd,"%c%c%c",0,0,170);
-                                       else
-                                       {
-                                               output=(unsigned)(0.5+pow((double)(dem[indx].data[x0][y0]-min_elevation),one_over_gamma)*conversion);
-                                               fprintf(fd,"%c%c%c",output,output,output);
-                                       }
+                                       cityorcounty=1;
                                }
 
-                               else switch ((mask&248)>>3)
+                               if (cityorcounty==0)
                                {
-                                       case 0:
-                                       /* Inside range, but no coverage.
-                                          Display Sea Level / Terrain */
+                                       if (loss>maxdB)
+
+                                       { /* Display land or sea elevation */
+
+                                               if (dem[indx].data[x0][y0]==0)
+                                                       fprintf(fd,"%c%c%c",0,0,170);
+                                               else
+                                               {
+                                                       /* Elevation: Greyscale */
+                                                       output=(unsigned)(0.5+pow((double)(dem[indx].data[x0][y0]-min_elevation),one_over_gamma)*conversion);
+                                                       fprintf(fd,"%c%c%c",output,output,output);
+                                               }
+                                       }
 
-                                       if (dem[indx].data[x0][y0]==0)
-                                               fprintf(fd,"%c%c%c",0,0,170);
-                                       else
+                                       else switch (loss)
                                        {
-                                               /* Elevation: Greyscale */
-                                               output=(unsigned)(0.5+pow((double)(dem[indx].data[x0][y0]-min_elevation),one_over_gamma)*conversion);
-                                               fprintf(fd,"%c%c%c",output,output,output);
-                                       }
+                                               /* Plot signal loss in color */
 
-                                       break;
+                                               case 80:
+                                               fprintf(fd,"%c%c%c",255,0,0);
+                                               break;
 
-                                       case 1:
-                                       /* Green */
-                                       fprintf(fd,"%c%c%c",0,255,0);
-                                       break;
+                                               case 90:
+                                               fprintf(fd,"%c%c%c",255,128,0);
+                                               break;
 
-                                       case 2:
-                                       /* Pink */
-                                       fprintf(fd,"%c%c%c",255,192,203);
-                                       break;
+                                               case 100:
+                                               fprintf(fd,"%c%c%c",255,165,0);
+                                               break;
 
-                                       case 3:
-                                       /* Cyan */
-                                       fprintf(fd,"%c%c%c",0,255,255);
-                                       break;
+                                               case 110:
+                                               fprintf(fd,"%c%c%c",255,206,0);
+                                               break;
 
-                                       case 4:
-                                       /* Yellow */
-                                       fprintf(fd,"%c%c%c",255,255,0);
-                                       break;
+                                               case 120:
+                                               fprintf(fd,"%c%c%c",255,255,0);
+                                               break;
 
-                                       case 5:
-                                       /* Medium Violet */
-                                       fprintf(fd,"%c%c%c",161,131,224);
-                                       break;
+                                               case 130:
+                                               fprintf(fd,"%c%c%c",184,255,0);
+                                               break;
 
-                                       case 6:
-                                       /* Orange */
-                                       fprintf(fd,"%c%c%c",255,165,0);
-                                       break;
+                                               case 140:
+                                               fprintf(fd,"%c%c%c",0,255,0);
+                                               break;
 
-                                       case 7:
-                                       /* Light Green */
-                                       fprintf(fd,"%c%c%c",193,255,193);
-                                       break;
+                                               case 150:
+                                               fprintf(fd,"%c%c%c",0,208,0);
+                                               break;
 
-                                       case 8:
-                                       /* Red Pink */
-                                       fprintf(fd,"%c%c%c",255,108,108);
-                                       break;
+                                               case 160:
+                                               fprintf(fd,"%c%c%c",0,196,196);
+                                               break;
 
-                                       case 9:
-                                       /* TX1 + TX4: Green Yellow */
-                                       fprintf(fd,"%c%c%c",173,255,47);
-                                       break;
+                                               case 170:
+                                               fprintf(fd,"%c%c%c",0,148,255);
+                                               break;
 
-                                       case 10:
-                                       /* Blanched Almond */
-                                       fprintf(fd,"%c%c%c",255,235,184);
-                                       break;
+                                               case 180:
+                                               fprintf(fd,"%c%c%c",80,80,255);
+                                               break;
 
-                                       case 11:
-                                       /* Dark Turquoise */
-                                       fprintf(fd,"%c%c%c",0,206,209);
-                                       break;
+                                               case 190:
+                                               fprintf(fd,"%c%c%c",0,38,255);
+                                               break;
 
-                                       case 12:
-                                       /* Tan */
-                                       fprintf(fd,"%c%c%c",210,180,140);
-                                       break;
+                                               case 200:
+                                               fprintf(fd,"%c%c%c",142,63,255);
+                                               break;
 
-                                       case 13:
-                                       /* Magenta 1 */
-                                       fprintf(fd,"%c%c%c",243,110,205);
-                                       break;
+                                               case 210:
+                                               fprintf(fd,"%c%c%c",196,54,255);
+                                               break;
 
-                                       case 14:
-                                       /* Gold2 */
-                                       fprintf(fd,"%c%c%c",238,201,0);
-                                       break;
+                                               case 220:
+                                               fprintf(fd,"%c%c%c",255,0,255);
+                                               break;
 
-                                       case 15:
-                                       /* Medium Spring Green */
-                                       fprintf(fd,"%c%c%c",0,250,154);
-                                       break;
+                                               case 230:
+                                               fprintf(fd,"%c%c%c",255,194,204);
+                                               break;
 
-                                       case 16:
-                                       /* Very light Blue */
-                                       fprintf(fd,"%c%c%c",244,244,255);
-                                       break;
+                                               default:
 
-                                       default:
-                                       /* Land / Sea */
-                                       if (dem[indx].data[x0][y0]==0)
-                                               fprintf(fd,"%c%c%c",0,0,170);
-                                       else
-                                       {
-                                               /* Elevation: Greyscale */
-                                               output=(unsigned)(0.5+pow((double)(dem[indx].data[x0][y0]-min_elevation),one_over_gamma)*conversion);
-                                               fprintf(fd,"%c%c%c",output,output,output);
+                                               if (dem[indx].data[x0][y0]==0)
+                                                       fprintf(fd,"%c%c%c",0,0,170);
+                                               else
+                                               {
+                                                       /* Elevation: Greyscale */
+                                                       output=(unsigned)(0.5+pow((double)(dem[indx].data[x0][y0]-min_elevation),one_over_gamma)*conversion);
+                                                       fprintf(fd,"%c%c%c",output,output,output);
+                                               }
                                        }
                                }
                        }
+
+                       else
+                       {
+                               /* We should never get here, but if */
+                               /* we do, display the region as black */
+
+                               fprintf(fd,"%c%c%c",0,0,0);
+                       }
                }
        }
 
+       /* Display legend along bottom of image */
+
        x0=width/16;
 
        for (y0=0; y0<30; y0++)
@@ -2572,78 +3398,63 @@ void WritePPMLR(char *filename)
                                switch (t)
                                {
                                        case 0:
-                                       /* Green */
-                                       fprintf(fd,"%c%c%c",0,255,0);
+                                       fprintf(fd,"%c%c%c",255,0,0);
                                        break;
 
                                        case 1:
-                                       /* Pink */
-                                       fprintf(fd,"%c%c%c",255,192,203);
+                                       fprintf(fd,"%c%c%c",255,128,0);
                                        break;
 
                                        case 2:
-                                       /* Cyan */
-                                       fprintf(fd,"%c%c%c",0,255,255);
+                                       fprintf(fd,"%c%c%c",255,165,0);
                                        break;
 
                                        case 3:
-                                       /* Yellow */
-                                       fprintf(fd,"%c%c%c",255,255,0);
+                                       fprintf(fd,"%c%c%c",255,206,0);
                                        break;
 
                                        case 4:
-                                       /* Medium Violet */
-                                       fprintf(fd,"%c%c%c",161,131,224);
+                                       fprintf(fd,"%c%c%c",255,255,0);
                                        break;
 
                                        case 5:
-                                       /* Orange */
-                                       fprintf(fd,"%c%c%c",255,165,0);
+                                       fprintf(fd,"%c%c%c",184,255,0);
                                        break;
 
-                                       case 6:
-                                       /* Light Green */
-                                       fprintf(fd,"%c%c%c",193,255,193);
+                                       case 6:
+                                       fprintf(fd,"%c%c%c",0,255,0);
                                        break;
 
-                                       case 7:
-                                       /* Red Pink */
-                                       fprintf(fd,"%c%c%c",255,108,108);
+                                       case 7:
+                                       fprintf(fd,"%c%c%c",0,208,0);
                                        break;
 
                                        case 8:
-                                       /* Green Yellow */
-                                       fprintf(fd,"%c%c%c",173,255,47);
+                                       fprintf(fd,"%c%c%c",0,196,196);
                                        break;
 
                                        case 9:
-                                       /* Blanched Almond */
-                                       fprintf(fd,"%c%c%c",255,235,184);
+                                       fprintf(fd,"%c%c%c",0,148,255);
                                        break;
 
                                        case 10:
-                                       /* Dark Turquoise */
-                                       fprintf(fd,"%c%c%c",0,206,209);
+                                       fprintf(fd,"%c%c%c",80,80,255);
                                        break;
 
                                        case 11:
-                                       /* Tan */
-                                       fprintf(fd,"%c%c%c",210,180,140);
+                                       fprintf(fd,"%c%c%c",0,38,255);
                                        break;
 
                                        case 12:
-                                       /* Magenta 1 */
-                                       fprintf(fd,"%c%c%c",243,110,205);
+                                       fprintf(fd,"%c%c%c",142,63,255);
                                        break;
 
                                        case 13:
-                                       /* Gold2 */
-                                       fprintf(fd,"%c%c%c",238,201,0);
+                                       fprintf(fd,"%c%c%c",196,54,255);
                                        break;
 
                                        case 14:
-                                       /* Medium Spring Green */
-                                       fprintf(fd,"%c%c%c",0,250,154);
+                                       fprintf(fd,"%c%c%c",255,0,255);
                                        break;
 
                                        case 255:
@@ -2652,8 +3463,7 @@ void WritePPMLR(char *filename)
                                        break;
 
                                        default:
-                                       /* Very Light Blue */
-                                       fprintf(fd,"%c%c%c",244,244,255);
+                                       fprintf(fd,"%c%c%c",255,194,204);
                                }
                        } 
                }
@@ -2671,18 +3481,24 @@ void GraphTerrain(struct site source, struct site destination, char *name)
           and destination locations.  "filename" is the name assigned
           to the output file generated by gnuplot.  The filename extension
           is used to set gnuplot's terminal setting and output file type.
-          If no extension is found, .gif is assumed.  */
+          If no extension is found, .png is assumed.  */
 
-       int x, y, z;
-       char filename[255], term[15], ext[15];
-       FILE *fd=NULL;
+       int     x, y, z;
+       char    filename[255], term[30], ext[15];
+       FILE    *fd=NULL;
 
        ReadPath(destination,source);
 
        fd=fopen("profile.gp","wb");
 
        for (x=0; x<path.length; x++)
-               fprintf(fd,"%f\t%f\n",path.distance[x],path.elevation[x]);
+       {
+               if (metric)
+                       fprintf(fd,"%f\t%f\n",KM_PER_MILE*path.distance[x],METERS_PER_FOOT*path.elevation[x]);
+
+               else
+                       fprintf(fd,"%f\t%f\n",path.distance[x],path.elevation[x]);
+       }
 
        fclose(fd);
 
@@ -2691,8 +3507,8 @@ void GraphTerrain(struct site source, struct site destination, char *name)
                /* Default filename and output file type */
 
                strncpy(filename,"profile\0",8);
-               strncpy(term,"gif\0",4);
-               strncpy(ext,"gif\0",4);
+               strncpy(term,"png\0",4);
+               strncpy(ext,"png\0",4);
        }
 
        else
@@ -2716,11 +3532,11 @@ void GraphTerrain(struct site source, struct site destination, char *name)
                }
 
                else
-               {       /* No extension -- Default is gif */
+               {       /* No extension -- Default is png */
 
                        filename[x]=0;
-                       strncpy(term,"gif\0",4);
-                       strncpy(ext,"gif\0",4);
+                       strncpy(term,"png\0",4);
+                       strncpy(ext,"png\0",4);
                }
        }
 
@@ -2731,7 +3547,7 @@ void GraphTerrain(struct site source, struct site destination, char *name)
                strncpy(ext,"ps\0",3);
 
        else if (strncmp(ext,"ps",2)==0)
-               strncpy(term,"postscript\0",11);
+               strncpy(term,"postscript enhanced color\0",26);
 
        fprintf(stdout,"Writing \"%s.%s\"...",filename,ext);
        fflush(stdout);
@@ -2739,10 +3555,24 @@ void GraphTerrain(struct site source, struct site destination, char *name)
        fd=fopen("splat.gp","w");
        fprintf(fd,"set grid\n");
        fprintf(fd,"set autoscale\n");
+       fprintf(fd,"set encoding iso_8859_1\n");
        fprintf(fd,"set term %s\n",term);
-       fprintf(fd,"set title \"SPLAT! Terrain Profile\"\n");
-       fprintf(fd,"set xlabel \"Distance Between %s and %s (miles)\"\n",destination.name,source.name);
-       fprintf(fd,"set ylabel \"Ground Elevation Above Sea Level (feet)\"\n");
+       fprintf(fd,"set title \"SPLAT! Terrain Profile Between %s and %s (%.2f%c Azimuth)\"\n",destination.name, source.name, Azimuth(destination,source),176);
+
+       if (metric)
+       {
+               fprintf(fd,"set xlabel \"Distance Between %s and %s (%.2f kilometers)\"\n",destination.name,source.name,KM_PER_MILE*Distance(source,destination));
+               fprintf(fd,"set ylabel \"Ground Elevation Above Sea Level (meters)\"\n");
+
+
+       }
+
+       else
+       {
+               fprintf(fd,"set xlabel \"Distance Between %s and %s (%.2f miles)\"\n",destination.name,source.name,Distance(source,destination));
+               fprintf(fd,"set ylabel \"Ground Elevation Above Sea Level (feet)\"\n");
+       }
+
        fprintf(fd,"set output \"%s.%s\"\n",filename,ext);
        fprintf(fd,"plot \"profile.gp\" title \"\" with lines\n");
        fclose(fd);
@@ -2768,13 +3598,13 @@ void GraphElevation(struct site source, struct site destination, char *name)
           and destination locations.  "filename" is the name assigned
           to the output file generated by gnuplot.  The filename extension
           is used to set gnuplot's terminal setting and output file type.
-          If no extension is found, .gif is assumed. */
+          If no extension is found, .png is assumed. */
 
-       int x, y, z;
-       char filename[255], term[15], ext[15];
-       double angle, refangle, maxangle=-90.0;
-       struct site remote;
-       FILE *fd=NULL, *fd2=NULL;
+       int     x, y, z;
+       char    filename[255], term[30], ext[15];
+       double  angle, refangle, maxangle=-90.0;
+       struct  site remote;
+       FILE    *fd=NULL, *fd2=NULL;
 
        ReadPath(destination,source);  /* destination=RX, source=TX */
        refangle=ElevationAngle(destination,source);
@@ -2788,15 +3618,34 @@ void GraphElevation(struct site source, struct site destination, char *name)
                remote.lon=path.lon[x];
                remote.alt=0.0;
                angle=ElevationAngle(destination,remote);
-               fprintf(fd,"%f\t%f\n",path.distance[x],angle);
-               fprintf(fd2,"%f\t%f\n",path.distance[x],refangle);
+
+               if (metric)
+               {
+                       fprintf(fd,"%f\t%f\n",KM_PER_MILE*path.distance[x],angle);
+                       fprintf(fd2,"%f\t%f\n",KM_PER_MILE*path.distance[x],refangle);
+               }
+
+               else
+               {
+                       fprintf(fd,"%f\t%f\n",path.distance[x],angle);
+                       fprintf(fd2,"%f\t%f\n",path.distance[x],refangle);
+               }
 
                if (angle>maxangle)
                        maxangle=angle;
        }
 
-       fprintf(fd,"%f\t%f\n",path.distance[path.length-1],refangle);
-       fprintf(fd2,"%f\t%f\n",path.distance[path.length-1],refangle);
+       if (metric)
+       {
+               fprintf(fd,"%f\t%f\n",KM_PER_MILE*path.distance[path.length-1],refangle);
+               fprintf(fd2,"%f\t%f\n",KM_PER_MILE*path.distance[path.length-1],refangle);
+       }
+
+       else
+       {
+               fprintf(fd,"%f\t%f\n",path.distance[path.length-1],refangle);
+               fprintf(fd2,"%f\t%f\n",path.distance[path.length-1],refangle);
+       }
 
        fclose(fd);
        fclose(fd2);
@@ -2806,8 +3655,8 @@ void GraphElevation(struct site source, struct site destination, char *name)
                /* Default filename and output file type */
 
                strncpy(filename,"profile\0",8);
-               strncpy(term,"gif\0",4);
-               strncpy(ext,"gif\0",4);
+               strncpy(term,"png\0",4);
+               strncpy(ext,"png\0",4);
        }
 
        else
@@ -2831,11 +3680,11 @@ void GraphElevation(struct site source, struct site destination, char *name)
                }
 
                else
-               {       /* No extension -- Default is gif */
+               {       /* No extension -- Default is png */
 
                        filename[x]=0;
-                       strncpy(term,"gif\0",4);
-                       strncpy(ext,"gif\0",4);
+                       strncpy(term,"png\0",4);
+                       strncpy(ext,"png\0",4);
                }
        }
 
@@ -2846,7 +3695,7 @@ void GraphElevation(struct site source, struct site destination, char *name)
                strncpy(ext,"ps\0",3);
 
        else if (strncmp(ext,"ps",2)==0)
-               strncpy(term,"postscript\0",11);
+               strncpy(term,"postscript enhanced color\0",26);
 
        fprintf(stdout,"Writing \"%s.%s\"...",filename,ext);
        fflush(stdout);
@@ -2855,12 +3704,19 @@ void GraphElevation(struct site source, struct site destination, char *name)
 
        fprintf(fd,"set grid\n");
        fprintf(fd,"set yrange [%2.3f to %2.3f]\n", (-fabs(refangle)-0.25), maxangle+0.25);
+       fprintf(fd,"set encoding iso_8859_1\n");
        fprintf(fd,"set term %s\n",term);
-       fprintf(fd,"set title \"SPLAT! Elevation Profile\"\n");
-       fprintf(fd,"set xlabel \"Distance Between %s and %s (miles)\"\n",destination.name,source.name);
-       fprintf(fd,"set ylabel \"Elevation Angle Along Path Between %s and %s (degrees)\"\n",destination.name,source.name);
+       fprintf(fd,"set title \"SPLAT! Elevation Profile Between %s and %s (%.2f%c azimuth)\"\n",destination.name,source.name,Azimuth(destination,source),176);
+
+       if (metric)
+               fprintf(fd,"set xlabel \"Distance Between %s and %s (%.2f kilometers)\"\n",destination.name,source.name,KM_PER_MILE*Distance(source,destination));
+       else
+               fprintf(fd,"set xlabel \"Distance Between %s and %s (%.2f miles)\"\n",destination.name,source.name,Distance(source,destination));
+
+
+       fprintf(fd,"set ylabel \"Elevation Angle Along LOS Path Between %s and %s (degrees)\"\n",destination.name,source.name);
        fprintf(fd,"set output \"%s.%s\"\n",filename,ext);
-       fprintf(fd,"plot \"profile.gp\" title \"Real Earth Profile\" with lines, \"reference.gp\" title \"Line Of Sight Path\" with lines\n");
+       fprintf(fd,"plot \"profile.gp\" title \"Real Earth Profile\" with lines, \"reference.gp\" title \"Line of Sight Path (%.2f%c elevation)\" with lines\n",refangle,176);
 
        fclose(fd);
                        
@@ -2880,68 +3736,209 @@ void GraphElevation(struct site source, struct site destination, char *name)
                fprintf(stderr,"\n*** ERROR: Error occurred invoking gnuplot!\n");
 }
 
-void GraphHeight(struct site source, struct site destination, char *name)
+void GraphHeight(struct site source, struct site destination, char *name, double f, unsigned char n)
 {
        /* This function invokes gnuplot to generate an appropriate
           output file indicating the terrain profile between the source
-          and destination locations.  What is plotted is the height of land
-          above or below a straight line between the receibe and transmit
-          sites. "filename" is the name assigned to the output file
-          generated by gnuplot.  The filename extension is used to
-          set gnuplot's terminal setting and output file type.
-          If no extension is found, .gif is assumed. */
-
-       int x, y, z;
-       char filename[255], term[15], ext[15];
-       double a, b, c, height, refangle, cangle, maxheight=-100000.0,
-              minheight=100000.0;
-       struct site remote;
-       FILE *fd=NULL, *fd2=NULL;
+          and destination locations referenced to the line-of-sight path
+          between the receive and transmit sites.  "filename" is the name
+          assigned to the output file generated by gnuplot.  The filename
+          extension is used to set gnuplot's terminal setting and output
+          file type.  If no extension is found, .png is assumed. */
+
+       int     x, y, z;
+       char    filename[255], term[30], ext[15];
+       double  a, b, c, height=0.0, refangle, cangle, maxheight=-100000.0,
+               minheight=100000.0, lambda=0.0, f_zone=0.0, fpt6_zone=0.0,
+               nm=0.0, nb=0.0, ed=0.0, es=0.0, r=0.0, d=0.0, d1=0.0,
+               terrain, azimuth, distance, dheight=0.0, minterrain=100000.0,
+               minearth=100000.0, miny, maxy, min2y, max2y;
+       struct  site remote;
+       FILE    *fd=NULL, *fd2=NULL, *fd3=NULL, *fd4=NULL, *fd5=NULL;
 
        ReadPath(destination,source);  /* destination=RX, source=TX */
+       azimuth=Azimuth(destination,source);
+       distance=Distance(destination,source);
        refangle=ElevationAngle(destination,source);
        b=GetElevation(destination)+destination.alt+earthradius;
 
+       /* Wavelength and path distance (great circle) in feet. */
+
+       if (f)
+       {
+               lambda=9.8425e8/(f*1e6);
+               d=5280.0*path.distance[path.length-1];
+       }
+
+       if (n)
+       {
+               ed=GetElevation(destination);
+               es=GetElevation(source);
+               nb=-destination.alt-ed;
+               nm=(-source.alt-es-nb)/(path.distance[path.length-1]);
+       }
+
        fd=fopen("profile.gp","wb");
        fd2=fopen("reference.gp","wb");
+       fd5=fopen("curvature.gp", "wb");
 
-       for (x=1; x<path.length-1; x++)
+       if (f)
+       {
+               fd3=fopen("fresnel.gp", "wb");
+               fd4=fopen("fresnel_pt_6.gp", "wb");
+       }
+
+       for (x=0; x<path.length; x++)
        {
                remote.lat=path.lat[x];
                remote.lon=path.lon[x];
                remote.alt=0.0;
 
-               a=GetElevation(remote)+earthradius;
+               terrain=GetElevation(remote);
 
-               cangle=5280.0*Distance(destination,remote)/earthradius;
+               if (x==0)
+                       terrain+=destination.alt;  /* RX antenna spike */
 
+               a=terrain+earthradius;
+               cangle=5280.0*Distance(destination,remote)/earthradius;
                c=b*sin(refangle*deg2rad+HALFPI)/sin(HALFPI-refangle*deg2rad-cangle);
 
                height=a-c;
 
-               fprintf(fd,"%f\t%f\n",path.distance[x],height);
-               fprintf(fd2,"%f\t%f\n",path.distance[x],0.);
+               /* Per Fink and Christiansen, Electronics
+                * Engineers' Handbook, 1989:
+                *
+                *   H = sqrt(lamba * d1 * (d - d1)/d)
+                *
+                * where H is the distance from the LOS
+                * path to the first Fresnel zone boundary.
+                */
+
+               if (f)
+               {
+                       d1=5280.0*path.distance[x];
+                       f_zone=-1*sqrt(lambda*d1*(d-d1)/d);
+                       fpt6_zone=0.6*f_zone;
+               }
+
+               if (n)
+               {
+                       r=-(nm*path.distance[x])-nb;
+                       height+=r;
+
+                       if (f>0) 
+                       {
+                               f_zone+=r;
+                               fpt6_zone+=r;
+                       }
+               }
+
+               else
+                       r=0.0;
+
+               if (metric)
+               {
+                       fprintf(fd,"%f\t%f\n",KM_PER_MILE*path.distance[x],METERS_PER_FOOT*height);
+                       fprintf(fd2,"%f\t%f\n",KM_PER_MILE*path.distance[x],METERS_PER_FOOT*r);
+                       fprintf(fd5,"%f\t%f\n",KM_PER_MILE*path.distance[x],METERS_PER_FOOT*(height-terrain));
+               }
+
+               else
+               {
+                       fprintf(fd,"%f\t%f\n",path.distance[x],height);
+                       fprintf(fd2,"%f\t%f\n",path.distance[x],r);
+                       fprintf(fd5,"%f\t%f\n",path.distance[x],height-terrain);
+               }
+
+               if (f)
+               {
+                       if (metric)
+                       {
+                               fprintf(fd3,"%f\t%f\n",KM_PER_MILE*path.distance[x],METERS_PER_FOOT*f_zone);
+                               fprintf(fd4,"%f\t%f\n",KM_PER_MILE*path.distance[x],METERS_PER_FOOT*fpt6_zone);
+                       }
+
+                       else
+                       {
+                               fprintf(fd3,"%f\t%f\n",path.distance[x],f_zone);
+                               fprintf(fd4,"%f\t%f\n",path.distance[x],fpt6_zone);
+                       }
+
+                       if (f_zone<minheight)
+                               minheight=f_zone;
+               }
 
                if (height>maxheight)
                        maxheight=height;
 
                if (height<minheight)
                        minheight=height;
+
+               if (r>maxheight)
+                       maxheight=r;
+
+               if (terrain<minterrain)
+                       minterrain=terrain;
+
+               if ((height-terrain)<minearth)
+                       minearth=height-terrain;
+       }
+
+       if (n)
+               r=-(nm*path.distance[path.length-1])-nb;
+       else
+               r=0.0;
+
+       if (metric)
+       {
+               fprintf(fd,"%f\t%f\n",KM_PER_MILE*path.distance[path.length-1],METERS_PER_FOOT*r);
+               fprintf(fd2,"%f\t%f\n",KM_PER_MILE*path.distance[path.length-1],METERS_PER_FOOT*r);
+       }
+
+       else
+       {
+               fprintf(fd,"%f\t%f\n",path.distance[path.length-1],r);
+               fprintf(fd2,"%f\t%f\n",path.distance[path.length-1],r);
+       }
+
+       if (f)
+       {
+               if (metric)
+               {
+                       fprintf(fd3,"%f\t%f\n",KM_PER_MILE*path.distance[path.length-1],METERS_PER_FOOT*r);
+                       fprintf(fd4,"%f\t%f\n",KM_PER_MILE*path.distance[path.length-1],METERS_PER_FOOT*r);
+               }
+
+               else
+               {
+                       fprintf(fd3,"%f\t%f\n",path.distance[path.length-1],r);
+                       fprintf(fd4,"%f\t%f\n",path.distance[path.length-1],r);
+               }
        }
+       
+       if (r>maxheight)
+               maxheight=r;
 
-       fprintf(fd,"%f\t%f\n",path.distance[path.length-1],0.0);
-       fprintf(fd2,"%f\t%f\n",path.distance[path.length-1],0.0);
+       if (r<minheight)
+               minheight=r;
 
        fclose(fd);
        fclose(fd2);
+       fclose(fd5);
+
+       if (f)
+       {
+               fclose(fd3);
+               fclose(fd4);
+       }
 
        if (name[0]==0)
        {
                /* Default filename and output file type */
 
                strncpy(filename,"height\0",8);
-               strncpy(term,"gif\0",4);
-               strncpy(ext,"gif\0",4);
+               strncpy(term,"png\0",4);
+               strncpy(ext,"png\0",4);
        }
 
        else
@@ -2965,11 +3962,11 @@ void GraphHeight(struct site source, struct site destination, char *name)
                }
 
                else
-               {       /* No extension -- Default is gif */
+               {       /* No extension -- Default is png */
 
                        filename[x]=0;
-                       strncpy(term,"gif\0",4);
-                       strncpy(ext,"gif\0",4);
+                       strncpy(term,"png\0",4);
+                       strncpy(ext,"png\0",4);
                }
        }
 
@@ -2980,37 +3977,93 @@ void GraphHeight(struct site source, struct site destination, char *name)
                strncpy(ext,"ps\0",3);
 
        else if (strncmp(ext,"ps",2)==0)
-               strncpy(term,"postscript\0",11);
+               strncpy(term,"postscript enhanced color\0",26);
 
        fprintf(stdout,"Writing \"%s.%s\"...",filename,ext);
        fflush(stdout);
 
        fd=fopen("splat.gp","w");
 
-       minheight-=20.0;
-       maxheight+=20.0;
+       dheight=maxheight-minheight;
+       miny=minheight-0.15*dheight;
+       maxy=maxheight+0.05*dheight;
+
+       if (maxy<20.0)
+               maxy=20.0;
+
+       dheight=maxheight-minheight;
+       min2y=miny-minterrain+0.05*dheight;
 
-       if (maxheight<20.0)
-               maxheight=20.0;
+       if (minearth<min2y)
+       {
+               miny-=min2y-minearth+0.05*dheight;
+               min2y=minearth-0.05*dheight;
+       }
 
+       max2y=min2y+maxy-miny;
        fprintf(fd,"set grid\n");
-       fprintf(fd,"set yrange [%2.3f to %2.3f]\n", minheight, maxheight);
+       fprintf(fd,"set yrange [%2.3f to %2.3f]\n", metric?miny*METERS_PER_FOOT:miny, metric?maxy*METERS_PER_FOOT:maxy);
+       fprintf(fd,"set y2range [%2.3f to %2.3f]\n", metric?min2y*METERS_PER_FOOT:min2y, metric?max2y*METERS_PER_FOOT:max2y);
+       fprintf(fd,"set xrange [-0.5 to %2.3f]\n",metric?KM_PER_MILE*rint(distance+0.5):rint(distance+0.5));
+       fprintf(fd,"set encoding iso_8859_1\n");
        fprintf(fd,"set term %s\n",term);
-       fprintf(fd,"set title \"SPLAT! Height Profile\"\n");
-       fprintf(fd,"set xlabel \"Distance Between %s and %s (miles)\"\n",destination.name,source.name);
-       fprintf(fd,"set ylabel \"Ground Height Above Path Between %s and %s (feet)\"\n",destination.name,source.name);
+
+       if (f)
+               fprintf(fd,"set title \"SPLAT! Path Profile Between %s and %s (%.2f%c azimuth)\\nWith First Fresnel Zone\"\n",destination.name, source.name, azimuth,176);
+
+       else
+               fprintf(fd,"set title \"SPLAT! Height Profile Between %s and %s (%.2f%c azimuth)\"\n",destination.name, source.name, azimuth,176);
+
+       if (metric)
+               fprintf(fd,"set xlabel \"Distance Between %s and %s (%.2f kilometers)\"\n",destination.name,source.name,KM_PER_MILE*Distance(source,destination));
+       else
+               fprintf(fd,"set xlabel \"Distance Between %s and %s (%.2f miles)\"\n",destination.name,source.name,Distance(source,destination));
+
+       if (n)
+       {
+               if (metric)
+                       fprintf(fd,"set ylabel \"Normalized Height Referenced To LOS Path Between\\n%s and %s (meters)\"\n",destination.name,source.name);
+
+               else
+                       fprintf(fd,"set ylabel \"Normalized Height Referenced To LOS Path Between\\n%s and %s (feet)\"\n",destination.name,source.name);
+
+       }
+
+       else
+       {
+               if (metric)
+                       fprintf(fd,"set ylabel \"Height Referenced To LOS Path Between %s and %s (meters)\"\n",destination.name,source.name);
+
+               else
+                       fprintf(fd,"set ylabel \"Height Referenced To LOS Path Between %s and %s (feet)\"\n",destination.name,source.name);
+       }
+
        fprintf(fd,"set output \"%s.%s\"\n",filename,ext);
-       fprintf(fd,"plot \"profile.gp\" title \"Real Earth Profile\" with lines, \"reference.gp\" title \"Line Of Sight Path\" with lines\n");
+
+       if (f)
+               fprintf(fd,"plot \"profile.gp\" title \"Point-to-Point Profile\" with lines, \"reference.gp\" title \"Line of Sight Path\" with lines, \"curvature.gp\" axes x1y2 title \"Earth's Curvature Contour\" with lines, \"fresnel.gp\" axes x1y1 title \"First Fresnel Zone (%.3f MHz)\" with lines, \"fresnel_pt_6.gp\" title \"60%% of First Fresnel Zone\" with lines\n",f);
+
+       else
+               fprintf(fd,"plot \"profile.gp\" title \"Point-to-Point Profile\" with lines, \"reference.gp\" title \"Line Of Sight Path\" with lines, \"curvature.gp\" axes x1y2 title \"Earth's Curvature Contour\" with lines\n");
 
        fclose(fd);
-                       
+
        x=system("gnuplot splat.gp");
 
        if (x!=-1)
        {
                unlink("splat.gp");
                unlink("profile.gp");
-               unlink("reference.gp"); 
+               unlink("reference.gp");
+               unlink("curvature.gp");
+
+               if (f)
+               {
+                       unlink("fresnel.gp");
+                       unlink("fresnel_pt_6.gp");
+               }
+
                fprintf(stdout," Done!\n");
                fflush(stdout);
        }
@@ -3023,19 +4076,26 @@ void GraphLongley(struct site source, struct site destination, char *name)
 {
        /* This function invokes gnuplot to generate an appropriate
           output file indicating the Longley-Rice model loss between
-          the source and destination locations.   "filename" is the
+          the source and destination locations.  "filename" is the
           name assigned to the output file generated by gnuplot.
           The filename extension is used to set gnuplot's terminal
           setting and output file type.  If no extension is found,
-          .gif is assumed.  */
-
-       int x, y, z, errnum, errflag=0;
-       char filename[255], term[15], ext[15], strmode[100], report_name[80];
-       double maxloss=-100000.0, minloss=100000.0, loss, haavt, angle;
-       FILE *fd=NULL, *fd2=NULL;
+          .png is assumed. */
+
+       int     x, y, z, errnum, errflag=0;
+       char    filename[255], term[30], ext[15], strmode[100],
+               report_name[80], block=0;
+       double  maxloss=-100000.0, minloss=100000.0, loss, haavt,
+               angle1, angle2, azimuth, pattern=1.0, patterndB=0.0,
+               total_loss=0.0, cos_xmtr_angle, cos_test_angle=0.0,
+               source_alt, test_alt, dest_alt, source_alt2, dest_alt2,
+               distance, elevation, four_thirds_earth;
+       FILE    *fd=NULL, *fd2=NULL;
 
        sprintf(report_name,"%s-to-%s.lro",source.name,destination.name);
 
+       four_thirds_earth=EARTHRADIUS*(4.0/3.0);
+
        for (x=0; report_name[x]!=0; x++)
                if (report_name[x]==32 || report_name[x]==17 || report_name[x]==92 || report_name[x]==42 || report_name[x]==47)
                        report_name[x]='_';     
@@ -3046,54 +4106,155 @@ void GraphLongley(struct site source, struct site destination, char *name)
        fprintf(fd2,"Analysis of RF path conditions between %s and %s:\n",source.name, destination.name);
        fprintf(fd2,"\n-------------------------------------------------------------------------\n\n");
        fprintf(fd2,"Transmitter site: %s\n",source.name);
-       fprintf(fd2,"Site location: %.4f North / %.4f West",source.lat, source.lon);
-       fprintf(fd2, " (%s N / ", dec2dms(source.lat));
+
+       if (source.lat>=0.0)
+       {
+               fprintf(fd2,"Site location: %.4f North / %.4f West",source.lat, source.lon);
+               fprintf(fd2, " (%s N / ", dec2dms(source.lat));
+       }
+
+       else
+       {
+
+               fprintf(fd2,"Site location: %.4f South / %.4f West",-source.lat, source.lon);
+               fprintf(fd2, " (%s S / ", dec2dms(source.lat));
+       }
+       
        fprintf(fd2, "%s W)\n", dec2dms(source.lon));
-       fprintf(fd2,"Ground elevation: %.2f feet AMSL\n",GetElevation(source));
-       fprintf(fd2,"Antenna height: %.2f feet AGL / %.2f feet AMSL\n",source.alt, source.alt+GetElevation(source));
+
+       if (metric)
+       {
+               fprintf(fd2,"Ground elevation: %.2f meters AMSL\n",METERS_PER_FOOT*GetElevation(source));
+               fprintf(fd2,"Antenna height: %.2f meters AGL / %.2f meters AMSL\n",METERS_PER_FOOT*source.alt,METERS_PER_FOOT*(source.alt+GetElevation(source)));
+       }
+
+       else
+       {
+               fprintf(fd2,"Ground elevation: %.2f feet AMSL\n",GetElevation(source));
+               fprintf(fd2,"Antenna height: %.2f feet AGL / %.2f feet AMSL\n",source.alt, source.alt+GetElevation(source));
+       }
 
        haavt=haat(source);
 
        if (haavt>-4999.0)
-               fprintf(fd2,"Antenna height above average terrain: %.2f feet\n",haavt);
+       {
+               if (metric)
+                       fprintf(fd2,"Antenna height above average terrain: %.2f meters\n",METERS_PER_FOOT*haavt);
+               else
+                       fprintf(fd2,"Antenna height above average terrain: %.2f feet\n",haavt);
+       }
+
+       azimuth=Azimuth(source,destination);
+       angle1=ElevationAngle(source,destination);
+       angle2=ElevationAngle2(source,destination,earthradius);
+
+       if (got_azimuth_pattern || got_elevation_pattern)
+       {
+               x=(int)rint(10.0*(10.0-angle2));
+
+               if (x>=0 && x<=1000)
+                       pattern=(double)LR.antenna_pattern[(int)rint(azimuth)][x];
+
+               patterndB=20.0*log10(pattern);
+
+               fprintf(fd2,"Antenna pattern between %s and %s: %.3f (%.2f dB)\n",source.name, destination.name, pattern, patterndB);
+
+       }
+
+       if (metric)
+               fprintf(fd2,"Distance to %s: %.2f kilometers\n",destination.name,METERS_PER_FOOT*Distance(source,destination));
+
+       else
+               fprintf(fd2,"Distance to %s: %.2f miles.\n",destination.name,Distance(source,destination));
+
+       fprintf(fd2,"Azimuth to %s: %.2f degrees\n",destination.name,azimuth);
 
-       fprintf(fd2,"Distance to %s: %.2f miles.\n",destination.name,Distance(source,destination));
-       fprintf(fd2,"Azimuth to %s: %.2f degrees.\n",destination.name,Azimuth(source,destination));
+       if (angle1>=0.0)
+               fprintf(fd2,"Elevation angle to %s: %+.4f degrees\n",destination.name,angle1);
 
-       angle=ElevationAngle(source,destination);
+       else
+               fprintf(fd2,"Depression angle to %s: %+.4f degrees\n",destination.name,angle1);
 
-       if (angle>=0.0)
-               fprintf(fd2,"Angle of elevation between %s and %s: %+.4f degrees.\n",source.name,destination.name,angle);
+       if (angle1!=angle2)
+       {
+               if (angle2<0.0)
+                       fprintf(fd2,"Depression");
+               else
+                       fprintf(fd2,"Elevation");
 
-       if (angle<0.0)
-               fprintf(fd2,"Angle of depression between %s and %s: %+.4f degrees.\n",source.name,destination.name,angle);
+               fprintf(fd2," angle to the first obstruction: %+.4f degrees\n",angle2);
+       }
 
        fprintf(fd2,"\n-------------------------------------------------------------------------\n\n");
 
        /* Receiver */
 
        fprintf(fd2,"Receiver site: %s\n",destination.name);
-       fprintf(fd2,"Site location: %.4f North / %.4f West",destination.lat, destination.lon);
-       fprintf(fd2, " (%s N / ", dec2dms(destination.lat));
+
+       if (destination.lat>=0.0)
+       {
+               fprintf(fd2,"Site location: %.4f North / %.4f West",destination.lat, destination.lon);
+               fprintf(fd2, " (%s N / ", dec2dms(destination.lat));
+       }
+
+       else
+       {
+               fprintf(fd2,"Site location: %.4f South / %.4f West",-destination.lat, destination.lon);
+               fprintf(fd2, " (%s S / ", dec2dms(destination.lat));
+       }
+
        fprintf(fd2, "%s W)\n", dec2dms(destination.lon));
-       fprintf(fd2,"Ground elevation: %.2f feet AMSL\n",GetElevation(destination));
-       fprintf(fd2,"Antenna height: %.2f feet AGL / %.2f feet AMSL\n",destination.alt, destination.alt+GetElevation(destination));
+
+       if (metric)
+       {
+               fprintf(fd2,"Ground elevation: %.2f meters AMSL\n",METERS_PER_FOOT*GetElevation(destination));
+               fprintf(fd2,"Antenna height: %.2f meters AGL / %.2f meters AMSL\n",METERS_PER_FOOT*destination.alt, METERS_PER_FOOT*(destination.alt+GetElevation(destination)));
+       }
+
+       else
+       {
+               fprintf(fd2,"Ground elevation: %.2f feet AMSL\n",GetElevation(destination));
+               fprintf(fd2,"Antenna height: %.2f feet AGL / %.2f feet AMSL\n",destination.alt, destination.alt+GetElevation(destination));
+       }
 
        haavt=haat(destination);
 
        if (haavt>-4999.0)
-               fprintf(fd2,"Antenna height above average terrain: %.2f feet\n",haavt);
+       {
+               if (metric)
+                       fprintf(fd2,"Antenna height above average terrain: %.2f meters\n",METERS_PER_FOOT*haavt);
+               else
+                       fprintf(fd2,"Antenna height above average terrain: %.2f feet\n",haavt);
+       }
+
+       if (metric)
+               fprintf(fd2,"Distance to %s: %.2f kilometers\n",source.name,KM_PER_MILE*Distance(source,destination));
+
+       else
+               fprintf(fd2,"Distance to %s: %.2f miles\n",source.name,Distance(source,destination));
+
+       azimuth=Azimuth(destination,source);
+
+       angle1=ElevationAngle(destination,source);
+       angle2=ElevationAngle2(destination,source,earthradius);
+
+       fprintf(fd2,"Azimuth to %s: %.2f degrees.\n",source.name,azimuth);
 
-       fprintf(fd2,"Distance to %s: %.2f miles.\n",source.name,Distance(source,destination));
-       fprintf(fd2,"Azimuth to %s: %.2f degrees.\n",source.name,Azimuth(destination,source));
+       if (angle1>=0.0)
+               fprintf(fd2,"Elevation angle to %s: %+.4f degrees\n",source.name,angle1);
 
-       angle=ElevationAngle(destination,source);
+       else
+               fprintf(fd2,"Depression angle to %s: %+.4f degrees\n",source.name,angle1);
 
-       if (angle>=0.0)
-               fprintf(fd2,"Angle of elevation between %s and %s: %+.4f degrees.\n",destination.name,source.name,angle);
+       if (angle1!=angle2)
+       {
+               if (angle2<0.0)
+                       fprintf(fd2,"Depression");
+               else
+                       fprintf(fd2,"Elevation");
 
-       if (angle<0.0)
-               fprintf(fd2,"Angle of depression between %s and %s: %+.4f degrees.\n",destination.name,source.name,angle);
+               fprintf(fd2," angle to the first obstruction: %+.4f degrees\n",angle2);
+       }
 
        fprintf(fd2,"\n-------------------------------------------------------------------------\n\n");
 
@@ -3148,52 +4309,145 @@ void GraphLongley(struct site source, struct site destination, char *name)
 
        fprintf(fd2,")\nFraction of Situations: %.1lf%c\n",LR.conf*100.0,37);
        fprintf(fd2,"Fraction of Time: %.1lf%c\n",LR.rel*100.0,37);
-
        fprintf(fd2,"\n-------------------------------------------------------------------------\n\n");
 
        fprintf(fd2,"Analysis Results:\n\n");
 
-       ReadPath(source, destination);  /* destination=RX, source=TX */
+       ReadPath(source, destination);  /* source=TX, destination=RX */
+
+       /* Copy elevations along path into the elev_l[] array. */
 
-       elev_l[1]=0.04*METERS_PER_MILE;
+       for (x=0; x<path.length; x++)
+               elev_l[x+2]=path.elevation[x]*METERS_PER_FOOT;  
 
-       for (x=1; x<path.length; x++)
-               elev_l[x+1]=path.elevation[x]*METERS_PER_FOOT;  
+       if (metric)
+               fprintf(fd2,"Distance (km)");
+       else
+               fprintf(fd2,"Distance (mi)");
 
-       fprintf(fd2,"Distance (mi)\tLoss (dB)\tErrnum\tComment\n\n"); 
+       fprintf(fd2,"\tLoss (dB)\tErrnum\tComment\n\n");
 
        fd=fopen("profile.gp","w");
 
-       for (x=2; x<path.length; x++)
+       azimuth=rint(Azimuth(source,destination));
+
+       for (y=2; y<(path.length-1); y++)  /* path.length-1 avoids LR error */
        {
-               elev_l[0]=x-1;
+               distance=5280.0*path.distance[y];
+               source_alt=four_thirds_earth+source.alt+path.elevation[0];
+               dest_alt=four_thirds_earth+destination.alt+path.elevation[y];
+               dest_alt2=dest_alt*dest_alt;
+               source_alt2=source_alt*source_alt;
+
+               /* Calculate the cosine of the elevation of
+                  the receiver as seen by the transmitter. */
+
+               cos_xmtr_angle=((source_alt2)+(distance*distance)-(dest_alt2))/(2.0*source_alt*distance);
+
+               if (got_elevation_pattern)
+               {
+                       /* If an antenna elevation pattern is available, the
+                          following code determines the elevation angle to
+                          the first obstruction along the path. */
+
+                       for (x=2, block=0; x<y && block==0; x++)
+                       {
+                               distance=5280.0*(path.distance[y]-path.distance[x]);
+                               test_alt=four_thirds_earth+path.elevation[x];
+
+                               /* Calculate the cosine of the elevation
+                                  angle of the terrain (test point)
+                                  as seen by the transmitter. */
+
+                               cos_test_angle=((source_alt2)+(distance*distance)-(test_alt*test_alt))/(2.0*source_alt*distance);
+
+                               /* Compare these two angles to determine if
+                                  an obstruction exists.  Since we're comparing
+                                  the cosines of these angles rather than
+                                  the angles themselves, the sense of the
+                                  following "if" statement is reversed from
+                                  what it would be if the angles themselves
+                                  were compared. */
+
+                               if (cos_xmtr_angle>cos_test_angle)
+                                       block=1;
+                       }
+
+                       /* At this point, we have the elevation angle
+                          to the first obstruction (if it exists). */
+               }
+
+               /* Determine path loss for each point along the
+                  path using Longley-Rice's point_to_point mode
+                  starting at x=2 (number_of_points = 1), the
+                  shortest distance terrain can play a role in
+                  path loss. */
+
+               elev_l[0]=y-1;  /* (number of points - 1) */
+
+               /* Distance between elevation samples */
+               elev_l[1]=METERS_PER_MILE*(path.distance[y]-path.distance[y-1]);
 
                point_to_point(elev_l, source.alt*METERS_PER_FOOT, 
-                       destination.alt*METERS_PER_FOOT,
-                       LR.eps_dielect, LR.sgm_conductivity, LR.eno_ns_surfref,
-                       LR.frq_mhz, LR.radio_climate, LR.pol, LR.conf, LR.rel,
-                       loss, strmode, errnum);
+               destination.alt*METERS_PER_FOOT, LR.eps_dielect,
+               LR.sgm_conductivity, LR.eno_ns_surfref, LR.frq_mhz,
+               LR.radio_climate, LR.pol, LR.conf, LR.rel, loss,
+               strmode, errnum);
+
+               if (block)
+                       elevation=((acos(cos_test_angle))/deg2rad)-90.0;
+               else
+                       elevation=((acos(cos_xmtr_angle))/deg2rad)-90.0;
+
+               /* Integrate the antenna's radiation
+                  pattern into the overall path loss. */
+
+               x=(int)rint(10.0*(10.0-elevation));
+
+               if (x>=0 && x<=1000)
+               {
+                       pattern=(double)LR.antenna_pattern[(int)azimuth][x];
+
+                       if (pattern!=0.0)
+                               patterndB=20.0*log10(pattern);
+               }
+
+               else
+                       patterndB=0.0;
+
+               total_loss=loss-patterndB;
 
-                       /* Note: PASS BY REFERENCE ... loss and errnum are pass
-                       by reference, only used in this file by this function */
+               if (metric)
+               {
+                       fprintf(fd,"%f\t%f\n",KM_PER_MILE*(path.distance[path.length-1]-path.distance[y]),total_loss);
+                       fprintf(fd2,"%7.2f\t\t%7.2f\t\t  %d\t%s\n",KM_PER_MILE*path.distance[y],total_loss, errnum, strmode);
+               }
 
+               else
+               {
+                       fprintf(fd,"%f\t%f\n",path.distance[path.length-1]-path.distance[y],total_loss);
+                       fprintf(fd2,"%7.2f\t\t%7.2f\t\t  %d\t%s\n",path.distance[y],total_loss, errnum, strmode);
+               }
 
-               fprintf(fd,"%f\t%f\n",path.distance[path.length-1]-path.distance[x],loss);
-               fprintf(fd2,"%7.2f\t\t%7.2f\t\t  %d\t%s\n",path.distance[x],loss, errnum, strmode); 
                errflag|=errnum;
-                 
-               if (loss>maxloss)
-                       maxloss=loss;
 
-               if (loss<minloss)
-                       minloss=loss;
+               if (total_loss>maxloss)
+                       maxloss=total_loss;
+
+               if (total_loss<minloss)
+                       minloss=total_loss;
        }
 
        fclose(fd);
 
+       fprintf(fd2,"\nLongley-Rice path loss between %s and %s is %.2f dB.\n",source.name, destination.name, loss);
+
+       if (patterndB!=0.0)
+               fprintf(fd2,"Total path loss including TX antenna pattern is %.2f dB.\n",total_loss);
+
        if (errflag)
        {
-               fprintf(fd2,"\nNotes on \"errnum\"...\n\n");
+               fprintf(fd2,"\nNotes on \"errnum\":\n\n");
                fprintf(fd2,"  0: No error.  :-)\n");
                fprintf(fd2,"  1: Warning!  Some parameters are nearly out of range.\n");
                fprintf(fd2,"     Results should be used with caution.\n");
@@ -3204,7 +4458,11 @@ void GraphLongley(struct site source, struct site destination, char *name)
                fprintf(fd2,"    Results are probably invalid.\n\nEnd of Report\n");
        }
 
-       fprintf(stdout,"Longley-Rice Path Loss between %s and %s is %.2f db\n",source.name, destination.name, loss);
+       fprintf(stdout,"Longley-Rice path loss between %s and %s is %.2f dB.\n",source.name, destination.name, loss);
+
+       if (patterndB!=0.0)
+               fprintf(stdout,"Total path loss including TX antenna pattern is %.2f dB.\n",total_loss);
+
        fprintf(stdout,"Path Loss Report written to: \"%s\"\n",report_name);
        fflush(stdout);
 
@@ -3215,8 +4473,8 @@ void GraphLongley(struct site source, struct site destination, char *name)
                /* Default filename and output file type */
 
                strncpy(filename,"loss\0",5);
-               strncpy(term,"gif\0",4);
-               strncpy(ext,"gif\0",4);
+               strncpy(term,"png\0",4);
+               strncpy(ext,"png\0",4);
        }
 
        else
@@ -3240,11 +4498,11 @@ void GraphLongley(struct site source, struct site destination, char *name)
                }
 
                else
-               {       /* No extension -- Default is gif */
+               {       /* No extension -- Default is png */
 
                        filename[x]=0;
-                       strncpy(term,"gif\0",4);
-                       strncpy(ext,"gif\0",4);
+                       strncpy(term,"png\0",4);
+                       strncpy(ext,"png\0",4);
                }
        }
 
@@ -3255,7 +4513,7 @@ void GraphLongley(struct site source, struct site destination, char *name)
                strncpy(ext,"ps\0",3);
 
        else if (strncmp(ext,"ps",2)==0)
-               strncpy(term,"postscript\0",11);
+               strncpy(term,"postscript enhanced color\0",26);
 
        fprintf(stdout,"Writing \"%s.%s\"...",filename,ext);
        fflush(stdout);
@@ -3264,12 +4522,22 @@ void GraphLongley(struct site source, struct site destination, char *name)
 
        fprintf(fd,"set grid\n");
        fprintf(fd,"set yrange [%2.3f to %2.3f]\n", minloss, maxloss);
+       fprintf(fd,"set encoding iso_8859_1\n");
        fprintf(fd,"set term %s\n",term);
-       fprintf(fd,"set title \"SPLAT! Loss Profile\"\n");
-       fprintf(fd,"set xlabel \"Distance Between %s and %s (miles)\"\n",destination.name,source.name);
-       fprintf(fd,"set ylabel \"Longley-Rice Loss (dB)\"\n");
-       fprintf(fd,"set output \"%s.%s\"\n",filename,ext);
-       fprintf(fd,"plot \"profile.gp\" title \"Longley-Rice Loss\" with lines\n");
+       fprintf(fd,"set title \"SPLAT! Loss Profile Along Path Between %s and %s (%.2f%c azimuth)\"\n",destination.name, source.name, Azimuth(destination,source),176);
+
+       if (metric)
+               fprintf(fd,"set xlabel \"Distance Between %s and %s (%.2f kilometers)\"\n",destination.name,source.name,KM_PER_MILE*Distance(destination,source));
+       else
+               fprintf(fd,"set xlabel \"Distance Between %s and %s (%.2f miles)\"\n",destination.name,source.name,Distance(destination,source));
+
+       if (got_azimuth_pattern || got_elevation_pattern)
+               fprintf(fd,"set ylabel \"Total Path Loss (including TX antenna pattern) (dB)");
+       else
+               fprintf(fd,"set ylabel \"Longley-Rice Path Loss (dB)");
+
+       fprintf(fd,"\"\nset output \"%s.%s\"\n",filename,ext);
+       fprintf(fd,"plot \"profile.gp\" title \"Path Loss\" with lines\n");
 
        fclose(fd);
                        
@@ -3289,14 +4557,17 @@ void GraphLongley(struct site source, struct site destination, char *name)
                fprintf(stderr,"\n*** ERROR: Error occurred invoking gnuplot!\n");
 }
 
-void ObstructionReport(struct site xmtr, struct site rcvr, char report)
+void ObstructionReport(struct site xmtr, struct site rcvr, char report, double f)
 {
-       struct site result, result2, new_site;
-       double angle, haavt;
-       unsigned char block;
-       char report_name[80], string[255];
-       int x;
-       FILE *fd;
+       int     x;
+       struct  site site_x;
+       double  h_r, h_t, h_x, h_r_orig, cos_tx_angle, cos_test_angle,
+               cos_tx_angle_f1, cos_tx_angle_fpt6, haavt, d_tx, d_x,
+               h_r_f1, h_r_fpt6, h_f, h_los, lambda=0.0, azimuth,
+               pattern, patterndB, distance, angle1, angle2;
+       char    report_name[80], string[255], string_fpt6[255],
+               string_f1[255];
+       FILE    *fd;
 
        sprintf(report_name,"%s-to-%s.txt",xmtr.name,rcvr.name);
 
@@ -3307,111 +4578,570 @@ void ObstructionReport(struct site xmtr, struct site rcvr, char report)
        fd=fopen(report_name,"w");
 
        fprintf(fd,"\n\t\t--==[ SPLAT! v%s Obstruction Report ]==--\n\n",splat_version);
-       fprintf(fd,"Analysis of line-of-sight path conditions between %s and %s:\n",xmtr.name, rcvr.name);
+       fprintf(fd,"Analysis of great circle path between %s and %s:\n",xmtr.name, rcvr.name);
        fprintf(fd,"\n-------------------------------------------------------------------------\n\n");
        fprintf(fd,"Transmitter site: %s\n",xmtr.name);
-       fprintf(fd,"Site location: %.4f North / %.4f West",xmtr.lat, xmtr.lon);
-       fprintf(fd, " (%s N / ", dec2dms(xmtr.lat));
+
+
+       if (xmtr.lat>=0.0)
+       {
+               fprintf(fd,"Site location: %.4f North / %.4f West",xmtr.lat, xmtr.lon);
+               fprintf(fd, " (%s N / ", dec2dms(xmtr.lat));
+       }
+
+       else
+       {
+               fprintf(fd,"Site location: %.4f South / %.4f West",-xmtr.lat, xmtr.lon);
+               fprintf(fd, " (%s S / ", dec2dms(xmtr.lat));
+       }
+
        fprintf(fd, "%s W)\n", dec2dms(xmtr.lon));
-       fprintf(fd,"Ground elevation: %.2f feet AMSL\n",GetElevation(xmtr));
-       fprintf(fd,"Antenna height: %.2f feet AGL / %.2f feet AMSL\n",xmtr.alt, xmtr.alt+GetElevation(xmtr));
+
+       if (metric)
+       {
+               fprintf(fd,"Ground elevation: %.2f meters AMSL\n",METERS_PER_FOOT*GetElevation(xmtr));
+               fprintf(fd,"Antenna height: %.2f meters AGL / %.2f meters AMSL\n",METERS_PER_FOOT*xmtr.alt, METERS_PER_FOOT*(xmtr.alt+GetElevation(xmtr)));
+       }
+
+       else
+       {
+               fprintf(fd,"Ground elevation: %.2f feet AMSL\n",GetElevation(xmtr));
+               fprintf(fd,"Antenna height: %.2f feet AGL / %.2f feet AMSL\n",xmtr.alt, xmtr.alt+GetElevation(xmtr));
+       }
 
        haavt=haat(xmtr);
 
        if (haavt>-4999.0)
-               fprintf(fd,"Antenna height above average terrain: %.2f feet\n",haavt);
+       {
+               if (metric)
+                       fprintf(fd,"Antenna height above average terrain: %.2f meters\n",METERS_PER_FOOT*haavt);
+               else
+                       fprintf(fd,"Antenna height above average terrain: %.2f feet\n",haavt);
+       }
+
+       pattern=1.0;
+       patterndB=0.0;
+       distance=Distance(xmtr,rcvr);
+       azimuth=Azimuth(xmtr,rcvr);
+       angle1=ElevationAngle(xmtr,rcvr);
+       angle2=ElevationAngle2(xmtr,rcvr,earthradius);
+
+       if (got_azimuth_pattern || got_elevation_pattern)
+       {
+               x=(int)rint(10.0*(10.0-angle2));
+
+               if (x>=0 && x<=1000)
+                       pattern=(double)LR.antenna_pattern[(int)rint(azimuth)][x];
+
+               if (pattern!=1.0)
+               {
+                       fprintf(fd,"Antenna pattern toward %s: %.3f",rcvr.name,pattern);
+                       patterndB=20.0*log10(pattern);
+                       fprintf(fd," (%.2f dB)\n",patterndB);
+               }
+       }
+
+       if (metric)
+               fprintf(fd,"Distance to %s: %.2f kilometers\n",rcvr.name,KM_PER_MILE*distance);
+
+       else
+               fprintf(fd,"Distance to %s: %.2f miles\n",rcvr.name,distance);
+
+       fprintf(fd,"Azimuth to %s: %.2f degrees\n",rcvr.name,azimuth);
 
-       fprintf(fd,"Distance to %s: %.2f miles.\n",rcvr.name,Distance(xmtr,rcvr));
-       fprintf(fd,"Azimuth to %s: %.2f degrees.\n",rcvr.name,Azimuth(xmtr,rcvr));
+       if (angle1>=0.0)
+               fprintf(fd,"Elevation angle to %s: %+.4f degrees\n",rcvr.name,angle1);
 
-       angle=ElevationAngle(xmtr,rcvr);
+       else
+               fprintf(fd,"Depression angle to %s: %+.4f degrees\n",rcvr.name,angle1);
 
-       if (angle>=0.0)
-               fprintf(fd,"Angle of elevation between %s and %s: %+.4f degrees.\n",xmtr.name,rcvr.name,angle);
+       if (angle1!=angle2)
+       {
+               if (angle2<0.0)
+                       fprintf(fd,"Depression");
+               else
+                       fprintf(fd,"Elevation");
 
-       if (angle<0.0)
-               fprintf(fd,"Angle of depression between %s and %s: %+.4f degrees.\n",xmtr.name,rcvr.name,angle);
+               fprintf(fd," angle to the first obstruction: %+.4f degrees\n",angle2);
+       }
 
        fprintf(fd,"\n-------------------------------------------------------------------------\n\n");
 
        /* Receiver */
 
-       fprintf(fd,"Receiver site: %s\n",rcvr.name);
-       fprintf(fd,"Site location: %.4f North / %.4f West",rcvr.lat, rcvr.lon);
-       fprintf(fd, " (%s N / ", dec2dms(rcvr.lat));
-       fprintf(fd, "%s W)\n", dec2dms(rcvr.lon));
-       fprintf(fd,"Ground elevation: %.2f feet AMSL\n",GetElevation(rcvr));
-       fprintf(fd,"Antenna height: %.2f feet AGL / %.2f feet AMSL\n",rcvr.alt, rcvr.alt+GetElevation(rcvr));
+       fprintf(fd,"Receiver site: %s\n",rcvr.name);
+
+       if (rcvr.lat>=0.0)
+       {
+               fprintf(fd,"Site location: %.4f North / %.4f West",rcvr.lat, rcvr.lon);
+               fprintf(fd, " (%s N / ", dec2dms(rcvr.lat));
+       }
+
+       else
+       {
+               fprintf(fd,"Site location: %.4f South / %.4f West",-rcvr.lat, rcvr.lon);
+               fprintf(fd, " (%s S / ", dec2dms(rcvr.lat));
+       }
+
+       fprintf(fd, "%s W)\n", dec2dms(rcvr.lon));
+
+       if (metric)
+       {
+               fprintf(fd,"Ground elevation: %.2f meters AMSL\n",METERS_PER_FOOT*GetElevation(rcvr));
+               fprintf(fd,"Antenna height: %.2f meters AGL / %.2f meters AMSL\n",METERS_PER_FOOT*rcvr.alt, METERS_PER_FOOT*(rcvr.alt+GetElevation(rcvr)));
+       }
+
+       else
+       {
+               fprintf(fd,"Ground elevation: %.2f feet AMSL\n",GetElevation(rcvr));
+               fprintf(fd,"Antenna height: %.2f feet AGL / %.2f feet AMSL\n",rcvr.alt, rcvr.alt+GetElevation(rcvr));
+       }
+
+       haavt=haat(rcvr);
+
+       if (haavt>-4999.0)
+       {
+               if (metric)
+                       fprintf(fd,"Antenna height above average terrain: %.2f meters\n",METERS_PER_FOOT*haavt);
+               else
+                       fprintf(fd,"Antenna height above average terrain: %.2f feet\n",haavt);
+       }
+
+       azimuth=Azimuth(rcvr,xmtr);
+       angle1=ElevationAngle(rcvr,xmtr);
+       angle2=ElevationAngle2(rcvr,xmtr,earthradius);
+
+       if (metric)
+               fprintf(fd,"Distance to %s: %.2f kilometers\n",xmtr.name,KM_PER_MILE*distance);
+       else
+               fprintf(fd,"Distance to %s: %.2f miles\n",xmtr.name,distance);
+
+       fprintf(fd,"Azimuth to %s: %.2f degrees\n",xmtr.name,azimuth);
+
+       if (angle1>=0.0)
+               fprintf(fd,"Elevation to %s: %+.4f degrees\n",xmtr.name,angle1);
+
+       else
+               fprintf(fd,"Depression angle to %s: %+.4f degrees\n",xmtr.name,angle1);
+
+       if (angle1!=angle2)
+       {
+               if (angle2<0.0)
+                       fprintf(fd,"Depression");
+               else
+                       fprintf(fd,"Elevation");
+
+               fprintf(fd," angle to the first obstruction: %+.4f degrees\n",angle2);
+
+       }
+
+       fprintf(fd,"\n-------------------------------------------------------------------------\n\n");
+
+       if (report=='y')
+       {
+               /* Generate profile of the terrain.  Create the path
+                  from transmitter to receiver because that's the
+                  way the original los() function did it, and going
+                  the other way can yield slightly different results. */
+
+               ReadPath(xmtr,rcvr);
+               h_r=GetElevation(rcvr)+rcvr.alt+earthradius;
+               h_r_f1=h_r;
+               h_r_fpt6=h_r;
+               h_r_orig=h_r;
+               h_t=GetElevation(xmtr)+xmtr.alt+earthradius;
+               d_tx=5280.0*Distance(rcvr,xmtr);
+               cos_tx_angle=((h_r*h_r)+(d_tx*d_tx)-(h_t*h_t))/(2.0*h_r*d_tx);
+               cos_tx_angle_f1=cos_tx_angle;
+               cos_tx_angle_fpt6=cos_tx_angle;
+
+               if (f)
+                       lambda=9.8425e8/(f*1e6);
+
+               /* At each point along the path calculate the cosine
+                  of a sort of "inverse elevation angle" at the receiver.
+                  From the antenna, 0 deg. looks at the ground, and 90 deg.
+                  is parallel to the ground.
+
+                  Start at the receiver.  If this is the lowest antenna,
+                  then terrain obstructions will be nearest to it.  (Plus,
+                  that's the way the original los() did it.)
+
+                  Calculate cosines only.  That's sufficient to compare
+                  angles and it saves the extra computational burden of
+                  acos().  However, note the inverted comparison: if
+                  acos(A) > acos(B), then B > A. */
+               
+               for (x=path.length-1; x>0; x--)
+               {
+                       site_x.lat=path.lat[x];
+                       site_x.lon=path.lon[x];
+                       site_x.alt=0.0;
+
+                       h_x=GetElevation(site_x)+earthradius;
+                       d_x=5280.0*Distance(rcvr,site_x);
+
+                       /* Deal with the LOS path first. */
+
+                       cos_test_angle=((h_r*h_r)+(d_x*d_x)-(h_x*h_x))/(2.0*h_r*d_x);
+
+                       if (cos_tx_angle>cos_test_angle)
+                       {
+                               if (h_r==h_r_orig)
+                                       fprintf(fd,"SPLAT! detected obstructions at:\n\n");
+
+                               if (site_x.lat>=0.0)
+                               {
+                                       if (metric)
+                                               fprintf(fd,"\t%.4f N, %.4f W, %5.2f kilometers, %6.2f meters AMSL\n",site_x.lat, site_x.lon, KM_PER_MILE*(d_x/5280.0), METERS_PER_FOOT*(h_x-earthradius));
+                                       else
+                                               fprintf(fd,"\t%.4f N, %.4f W, %5.2f miles, %6.2f feet AMSL\n",site_x.lat, site_x.lon, d_x/5280.0, h_x-earthradius);
+                               }
+
+                               else
+                               {
+                                       if (metric)
+                                               fprintf(fd,"\t%.4f S, %.4f W, %5.2f kilometers, %6.2f meters AMSL\n",-site_x.lat, site_x.lon, KM_PER_MILE*(d_x/5280.0), METERS_PER_FOOT*(h_x-earthradius));
+                                       else
+
+                                               fprintf(fd,"\t%.4f S, %.4f W, %5.2f miles, %6.2f feet AMSL\n",-site_x.lat, site_x.lon, d_x/5280.0, h_x-earthradius);
+                               }
+                       }
+
+                       while (cos_tx_angle>cos_test_angle)
+                       {
+                               h_r+=1;
+                               cos_test_angle=((h_r*h_r)+(d_x*d_x)-(h_x*h_x))/(2.0*h_r*d_x);
+                               cos_tx_angle=((h_r*h_r)+(d_tx*d_tx)-(h_t*h_t))/(2.0*h_r*d_tx);
+                       }
+
+                       if (f)
+                       {
+                               /* Now clear the first Fresnel zone, but don't
+                                  clutter the obstruction report. */
+
+                               cos_tx_angle_f1=((h_r_f1*h_r_f1)+(d_tx*d_tx)-(h_t*h_t))/(2.0*h_r_f1*d_tx);
+                               h_los=sqrt(h_r_f1*h_r_f1+d_x*d_x-2*h_r_f1*d_x*cos_tx_angle_f1);
+                               h_f=h_los-sqrt(lambda*d_x*(d_tx-d_x)/d_tx);
+
+                               while (h_f<h_x)
+                               {
+                                       h_r_f1+=1;
+                                       cos_tx_angle_f1=((h_r_f1*h_r_f1)+(d_tx*d_tx)-(h_t*h_t))/(2.0*h_r_f1*d_tx);
+                                       h_los=sqrt(h_r_f1*h_r_f1+d_x*d_x-2*h_r_f1*d_x*cos_tx_angle_f1);
+                                       h_f=h_los-sqrt(lambda*d_x*(d_tx-d_x)/d_tx);
+                               }
+
+                               /* And clear the 60% F1 zone. */
+
+                               cos_tx_angle_fpt6=((h_r_fpt6*h_r_fpt6)+(d_tx*d_tx)-(h_t*h_t))/(2.0*h_r_fpt6*d_tx);
+                               h_los=sqrt(h_r_fpt6*h_r_fpt6+d_x*d_x-2*h_r_fpt6*d_x*cos_tx_angle_fpt6);
+                               h_f=h_los-0.6*sqrt(lambda*d_x*(d_tx-d_x)/d_tx);
+
+                               while (h_f<h_x)
+                               {
+                                       h_r_fpt6+=1;
+                                       cos_tx_angle_fpt6=((h_r_fpt6*h_r_fpt6)+(d_tx*d_tx)-(h_t*h_t))/(2.0*h_r_fpt6*d_tx);
+                                       h_los=sqrt(h_r_fpt6*h_r_fpt6+d_x*d_x-2*h_r_fpt6*d_x*cos_tx_angle_fpt6);
+                                       h_f=h_los-0.6*sqrt(lambda*d_x*(d_tx-d_x)/d_tx);
+                               }
+                       }
+               }
+               
+               if (h_r>h_r_orig)
+               {
+                       if (metric)
+                               sprintf(string,"\nAntenna at %s must be raised to at least %.2f meters AGL\nto clear all obstructions detected by SPLAT!\n",rcvr.name, METERS_PER_FOOT*(h_r-GetElevation(rcvr)-earthradius));
+                       else
+                               sprintf(string,"\nAntenna at %s must be raised to at least %.2f feet AGL\nto clear all obstructions detected by SPLAT!\n",rcvr.name, h_r-GetElevation(rcvr)-earthradius);
+               }
+
+               else
+                       sprintf(string,"\nNo obstructions to LOS path due to terrain were detected by SPLAT!\n");
+
+               if (f)
+               {
+                       if (h_r_fpt6>h_r_orig)
+                       {
+                               if (metric)
+                                       sprintf(string_fpt6,"\nAntenna at %s must be raised to at least %.2f meters AGL\nto clear 60%c of the first Fresnel zone.\n",rcvr.name, METERS_PER_FOOT*(h_r_fpt6-GetElevation(rcvr)-earthradius),37);
+
+                               else
+                                       sprintf(string_fpt6,"\nAntenna at %s must be raised to at least %.2f feet AGL\nto clear 60%c of the first Fresnel zone.\n",rcvr.name, h_r_fpt6-GetElevation(rcvr)-earthradius,37);
+                       }
+
+                       else
+                               sprintf(string_fpt6,"\n60%c of the first Fresnel zone is clear.\n",37);
+       
+                       if (h_r_f1>h_r_orig)
+                       {
+                               if (metric)
+                                       sprintf(string_f1,"\nAntenna at %s must be raised to at least %.2f meters AGL\nto clear the first Fresnel zone.\n",rcvr.name, METERS_PER_FOOT*(h_r_f1-GetElevation(rcvr)-earthradius));
+
+                               else                    
+                                       sprintf(string_f1,"\nAntenna at %s must be raised to at least %.2f feet AGL\nto clear the first Fresnel zone.\n",rcvr.name, h_r_f1-GetElevation(rcvr)-earthradius);
+
+                       }
+
+                       else
+                           sprintf(string_f1,"\nThe first Fresnel zone is clear.\n\n");
+               }
+       }
+       
+       fprintf(fd,"%s",string);
+
+       if (f)
+       {
+               fprintf(fd,"%s",string_f1);
+               fprintf(fd,"%s",string_fpt6);
+       }
+
+       fclose(fd);
+
+       /* Display report summary on terminal */
+
+       /* Line-of-sight status */
+
+       fprintf(stdout,"%s",string);
+
+       if (f)
+       {
+               /* Fresnel zone status */
+
+               fprintf(stdout,"%s",string_f1);
+               fprintf(stdout,"%s",string_fpt6);
+       }
+
+       fprintf(stdout, "\nObstruction report written to: \"%s\"\n",report_name);
+
+       fflush(stdout);
+}
+
+void SiteReport(struct site xmtr)
+{
+       char    report_name[80];
+       double  terrain;
+       int     x, azi;
+       FILE    *fd;
+
+       sprintf(report_name,"%s-site_report.txt",xmtr.name);
+
+       for (x=0; report_name[x]!=0; x++)
+               if (report_name[x]==32 || report_name[x]==17 || report_name[x]==92 || report_name[x]==42 || report_name[x]==47)
+                       report_name[x]='_';     
+
+       fd=fopen(report_name,"w");
+
+       fprintf(fd,"\n\t--==[ SPLAT! v%s Site Analysis Report For: %s ]==--\n\n",splat_version,xmtr.name);
+
+       fprintf(fd,"---------------------------------------------------------------------------\n\n");
+
+       if (xmtr.lat>=0.0)
+       {
+               fprintf(fd,"Site location: %.4f North / %.4f West",xmtr.lat, xmtr.lon);
+               fprintf(fd, " (%s N / ",dec2dms(xmtr.lat));
+       }
+
+       else
+       {
+               fprintf(fd,"Site location: %.4f South / %.4f West",-xmtr.lat, xmtr.lon);
+               fprintf(fd, " (%s S / ",dec2dms(xmtr.lat));
+       }
+
+       fprintf(fd, "%s W)\n",dec2dms(xmtr.lon));
+
+       if (metric)
+       {
+               fprintf(fd,"Ground elevation: %.2f meters AMSL\n",METERS_PER_FOOT*GetElevation(xmtr));
+               fprintf(fd,"Antenna height: %.2f meters AGL / %.2f meters AMSL\n",METERS_PER_FOOT*xmtr.alt, METERS_PER_FOOT*(xmtr.alt+GetElevation(xmtr)));
+       }
+
+       else
+       {
+               fprintf(fd,"Ground elevation: %.2f feet AMSL\n",GetElevation(xmtr));
+               fprintf(fd,"Antenna height: %.2f feet AGL / %.2f feet AMSL\n",xmtr.alt, xmtr.alt+GetElevation(xmtr));
+       }
+
+       terrain=haat(xmtr);
+
+       if (terrain>-4999.0)
+       {
+               if (metric)
+                       fprintf(fd,"Antenna height above average terrain: %.2f meters\n\n",METERS_PER_FOOT*terrain);
+               else
+                       fprintf(fd,"Antenna height above average terrain: %.2f feet\n\n",terrain);
+
+               /* Display the average terrain between 2 and 10 miles
+                  from the transmitter site at azimuths of 0, 45, 90,
+                  135, 180, 225, 270, and 315 degrees. */
+
+               for (azi=0; azi<=315; azi+=45)
+               {
+                       fprintf(fd,"Average terrain at %3d degrees azimuth: ",azi);
+                       terrain=AverageTerrain(xmtr,(double)azi,2.0,10.0);
+
+                       if (terrain>-4999.0)
+                       {
+                               if (metric)
+                                       fprintf(fd,"%.2f meters AMSL\n",METERS_PER_FOOT*terrain);
+                               else
+                                       fprintf(fd,"%.2f feet AMSL\n",terrain);
+                       }
+
+                       else
+                               fprintf(fd,"No terrain\n");
+               }
+       }
+
+       fprintf(fd,"\n---------------------------------------------------------------------------\n\n");
+       fclose(fd);
+       fprintf(stdout,"\nSite analysis report written to: \"%s\"\n",report_name);
+}
+
+void LoadTopoData(int max_lon, int min_lon, int max_lat, int min_lat)
+{
+       /* This function loads the SDF files required
+          to cover the limits of the region specified. */ 
+
+       int     x, y, width, ymin, ymax;
+
+       width=ReduceAngle(max_lon-min_lon);
+
+       if ((max_lon-min_lon)<=180.0)
+       {
+               for (y=0; y<=width; y++)
+                       for (x=min_lat; x<=max_lat; x++)
+                       {
+                               ymin=(int)(min_lon+(double)y);
+
+                               while (ymin<0)
+                                       ymin+=360;
+
+                               while (ymin>=360)
+                                       ymin-=360;
+
+                               ymax=ymin+1;
+
+                               while (ymax<0)
+                                       ymax+=360;
+
+                               while (ymax>=360)
+                                       ymax-=360;
+
+                               sprintf(string,"%d:%d:%d:%d",x, x+1, ymin, ymax);
+                               LoadSDF(string);
+                       }
+       }
+
+       else
+       {
+               for (y=0; y<=width; y++)
+                       for (x=min_lat; x<=max_lat; x++)
+                       {
+                               ymin=max_lon+y;
+
+                               while (ymin<0)
+                                       ymin+=360;
+
+                               while (ymin>=360)
+                                       ymin-=360;
+                                       
+                               ymax=ymin+1;
+
+                               while (ymax<0)
+                                       ymax+=360;
+
+                               while (ymax>=360)
+                                       ymax-=360;
+
+                               sprintf(string,"%d:%d:%d:%d",x, x+1, ymin, ymax);
+                               LoadSDF(string);
+                       }
+       }
+}
+
+int LoadPLI(char *filename)
+{
+       int     error=0, max_west, min_west, max_north, min_north;
+       char    string[80], *pointer=NULL;
+       double  latitude=0.0, longitude=0.0, azimuth=0.0, elevation=0.0,
+               loss=0.0;
+       FILE    *fd;
+
+       fd=fopen(filename,"r");
+
+       if (fd!=NULL)
+       {
+               fgets(string,78,fd);
+               pointer=strchr(string,';');
 
-       haavt=haat(rcvr);
+               if (pointer!=NULL)
+                       *pointer=0;
 
-       if (haavt>-4999.0)
-               fprintf(fd,"Antenna height above average terrain: %.2f feet\n",haavt);
+               sscanf(string,"%d, %d",&max_west, &min_west);
 
-       fprintf(fd,"Distance to %s: %.2f miles.\n",xmtr.name,Distance(xmtr,rcvr));
-       fprintf(fd,"Azimuth to %s: %.2f degrees.\n",xmtr.name,Azimuth(rcvr,xmtr));
+               fgets(string,78,fd);
+               pointer=strchr(string,';');
 
-       angle=ElevationAngle(rcvr,xmtr);
+               if (pointer!=NULL)
+                       *pointer=0;
 
-       if (angle>=0.0)
-               fprintf(fd,"Angle of elevation between %s and %s: %+.4f degrees.\n",rcvr.name,xmtr.name,angle);
+               sscanf(string,"%d, %d",&max_north, &min_north);
 
-       if (angle<0.0)
-               fprintf(fd,"Angle of depression between %s and %s: %+.4f degrees.\n",rcvr.name,xmtr.name,angle);
+               fgets(string,78,fd);
+               pointer=strchr(string,';');
 
-       fprintf(fd,"\n-------------------------------------------------------------------------\n\n");
+               if (pointer!=NULL)
+                       *pointer=0;
 
-       if (report=='y')
-       {
-               /* Write an Obstruction Report */
+               LoadTopoData(max_west-1, min_west, max_north-1, min_north);
 
-               new_site=rcvr;
-               result=los(xmtr,rcvr);
-               result2=result;
-               result2.alt-=1;
-               block=result.name[0];
+               fprintf(stdout,"\nReading \"%s\"... ",filename);
+               fflush(stdout);
 
-               if (block=='*')
-                       fprintf(fd,"SPLAT! detected obstructions at:\n\n");
+               fscanf(fd,"%lf, %lf, %lf, %lf, %lf",&latitude, &longitude, &azimuth, &elevation, &loss);
 
-               while (block=='*')
+               while (feof(fd)==0)
                {
-                       if (result.lat!=result2.lat || result.lon!=result2.lon || result.alt!=result2.alt)
-                               fprintf(fd,"\t%.4f N, %.4f W, %5.2f miles, %6.2f feet AMSL.\n",result.lat, result.lon, Distance(rcvr,result), result.alt);
+                       if (loss>225.0)
+                               loss=225.0;
+
+                       if (loss<75.0)
+                               loss=75.0;
 
-                       result2=result;
-                       new_site.alt+=1.0;
+                       loss-=75.0;
+                       loss/=10.0;
+                       loss+=1.0;
 
-                       /* Can you hear me now? :-) */
+                       if (loss<=(double)maxdB)
+                               OrMask(latitude,longitude,((unsigned char)(loss))<<3);
 
-                       result=los(xmtr,new_site);
-                       block=result.name[0];
+                       fscanf(fd,"%lf, %lf, %lf, %lf, %lf",&latitude, &longitude, &azimuth, &elevation, &loss);
                }
 
-               if (new_site.alt!=rcvr.alt)
-                       sprintf(string,"\nAntenna at %s must be raised to at least %.2f feet AGL\nto clear all obstructions detected by SPLAT!\n\n",rcvr.name, new_site.alt);
-               else
-                       sprintf(string,"\nNo obstructions due to terrain were detected by SPLAT!\n\n");
-       }
-
-       fprintf(fd,"%s",string);
+               fclose(fd);
 
-       fclose(fd);
+               fprintf(stdout," Done!\n");
+               fflush(stdout);
+       }
 
-       /* Display LOS status to terminal */
+       else
+               error=1;
 
-       fprintf(stdout,"%sObstruction report written to: \"%s\"\n",string,report_name);
-       fflush(stdout);
+       return error;
 }
 
-void SiteReport(struct site xmtr)
+void WriteKML(struct site source, struct site destination)
 {
-       char report_name[80];
-       double terrain;
-       int x, azi;
-       FILE *fd;
+       int     x, y;
+       char    block, report_name[80];
+       double  distance, rx_alt, tx_alt, cos_xmtr_angle,
+               azimuth, cos_test_angle, test_alt;
+       FILE    *fd=NULL;
 
-       sprintf(report_name,"%s-site_report.txt",xmtr.name);
+       ReadPath(source,destination);
+
+       sprintf(report_name,"%s-to-%s.kml",source.name,destination.name);
 
        for (x=0; report_name[x]!=0; x++)
                if (report_name[x]==32 || report_name[x]==17 || report_name[x]==92 || report_name[x]==42 || report_name[x]==47)
@@ -3419,86 +5149,260 @@ void SiteReport(struct site xmtr)
 
        fd=fopen(report_name,"w");
 
-       fprintf(fd,"\n\t--==[ SPLAT! v%s Site Analysis Report For: %s ]==--\n\n",splat_version,xmtr.name);
+       fprintf(fd,"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
+       fprintf(fd,"<kml xmlns=\"http://earth.google.com/kml/2.0\">\n");
+       fprintf(fd,"<!-- Generated by SPLAT! Version %s -->\n",splat_version);
+       fprintf(fd,"<Folder>\n");
+       fprintf(fd,"<name>SPLAT! Path</name>\n");
+       fprintf(fd,"<open>1</open>\n");
+       fprintf(fd,"<description>Path Between %s and %s</description>\n",source.name,destination.name);
+
+       fprintf(fd,"<Placemark>\n");
+       fprintf(fd,"    <name>%s</name>\n",source.name);
+       fprintf(fd,"    <description>\n");
+       fprintf(fd,"       Transmit Site\n");
+
+       if (source.lat>=0.0)
+               fprintf(fd,"       <BR>%s North</BR>\n",dec2dms(source.lat));
+       else
+               fprintf(fd,"       <BR>%s South</BR>\n",dec2dms(source.lat));
 
-       fprintf(fd,"---------------------------------------------------------------------------\n\n");
-       fprintf(fd,"Site location: %.4f North / %.4f West",xmtr.lat, xmtr.lon);
-       fprintf(fd, " (%s N / ",dec2dms(xmtr.lat));
-       fprintf(fd, "%s W)\n",dec2dms(xmtr.lon));
-       fprintf(fd,"Ground elevation: %.2f feet AMSL\n",GetElevation(xmtr));
-       fprintf(fd,"Antenna height: %.2f feet AGL / %.2f feet AMSL\n",xmtr.alt, xmtr.alt+GetElevation(xmtr));
+       fprintf(fd,"       <BR>%s West</BR>\n",dec2dms(source.lon));
 
-       terrain=haat(xmtr);
+       azimuth=Azimuth(source,destination);
+       distance=Distance(source,destination);
 
-       if (terrain>-4999.0)
+       if (metric)
+               fprintf(fd,"       <BR>%.2f km",distance*KM_PER_MILE);
+       else
+               fprintf(fd,"       <BR>%.2f miles",distance);
+
+       fprintf(fd," to %s</BR>\n       <BR>toward an azimuth of %.2f%c</BR>\n",destination.name,azimuth,176);
+
+       fprintf(fd,"    </description>\n");
+       fprintf(fd,"    <visibility>1</visibility>\n");
+       fprintf(fd,"    <Style>\n");
+       fprintf(fd,"      <IconStyle>\n");
+       fprintf(fd,"        <Icon>\n");
+       fprintf(fd,"          <href>root://icons/palette-5.png</href>\n");
+       fprintf(fd,"          <x>224</x>\n");
+       fprintf(fd,"          <y>224</y>\n");
+       fprintf(fd,"          <w>32</w>\n");
+       fprintf(fd,"          <h>32</h>\n");
+       fprintf(fd,"        </Icon>\n");
+       fprintf(fd,"      </IconStyle>\n");
+       fprintf(fd,"    </Style>\n");
+       fprintf(fd,"    <Point>\n");
+       fprintf(fd,"      <extrude>1</extrude>\n");
+       fprintf(fd,"      <altitudeMode>relativeToGround</altitudeMode>\n");
+       fprintf(fd,"      <coordinates>%f,%f,30</coordinates>\n",(source.lon<180.0?-source.lon:360.0-source.lon),source.lat);
+       fprintf(fd,"    </Point>\n");
+       fprintf(fd,"</Placemark>\n");
+
+       fprintf(fd,"<Placemark>\n");
+       fprintf(fd,"    <name>%s</name>\n",destination.name);
+       fprintf(fd,"    <description>\n");
+       fprintf(fd,"       Receive Site\n");
+
+       if (destination.lat>=0.0)
+               fprintf(fd,"       <BR>%s North</BR>\n",dec2dms(destination.lat));
+       else
+               fprintf(fd,"       <BR>%s South</BR>\n",dec2dms(destination.lat));
+
+       fprintf(fd,"       <BR>%s West</BR>\n",dec2dms(destination.lon));
+
+
+       if (metric)
+               fprintf(fd,"       <BR>%.2f km",distance*KM_PER_MILE);
+       else
+               fprintf(fd,"       <BR>%.2f miles",distance);
+
+       fprintf(fd," to %s</BR>\n       <BR>toward an azimuth of %.2f%c</BR>\n",source.name,Azimuth(destination,source),176);
+
+       fprintf(fd,"    </description>\n");
+       fprintf(fd,"    <visibility>1</visibility>\n");
+       fprintf(fd,"    <Style>\n");
+       fprintf(fd,"      <IconStyle>\n");
+       fprintf(fd,"        <Icon>\n");
+       fprintf(fd,"          <href>root://icons/palette-5.png</href>\n");
+       fprintf(fd,"          <x>224</x>\n");
+       fprintf(fd,"          <y>224</y>\n");
+       fprintf(fd,"          <w>32</w>\n");
+       fprintf(fd,"          <h>32</h>\n");
+       fprintf(fd,"        </Icon>\n");
+       fprintf(fd,"      </IconStyle>\n");
+       fprintf(fd,"    </Style>\n");
+       fprintf(fd,"    <Point>\n");
+       fprintf(fd,"      <extrude>1</extrude>\n");
+       fprintf(fd,"      <altitudeMode>relativeToGround</altitudeMode>\n");
+       fprintf(fd,"      <coordinates>%f,%f,30</coordinates>\n",(destination.lon<180.0?-destination.lon:360.0-destination.lon),destination.lat);
+       fprintf(fd,"    </Point>\n");
+       fprintf(fd,"</Placemark>\n");
+
+       fprintf(fd,"<Placemark>\n");
+       fprintf(fd,"<name>Point-to-Point Path</name>\n");
+       fprintf(fd,"  <visibility>1</visibility>\n");
+       fprintf(fd,"  <open>0</open>\n");
+       fprintf(fd,"  <Style>\n");
+       fprintf(fd,"    <LineStyle>\n");
+       fprintf(fd,"      <color>7fffffff</color>\n");
+       fprintf(fd,"    </LineStyle>\n");
+       fprintf(fd,"    <PolyStyle>\n");
+       fprintf(fd,"       <color>7fffffff</color>\n");
+       fprintf(fd,"    </PolyStyle>\n");
+       fprintf(fd,"  </Style>\n");
+       fprintf(fd,"  <LineString>\n");
+       fprintf(fd,"    <extrude>1</extrude>\n");
+       fprintf(fd,"    <tessellate>1</tessellate>\n");
+       fprintf(fd,"    <altitudeMode>relativeToGround</altitudeMode>\n");
+       fprintf(fd,"    <coordinates>\n");
+
+       for (x=0; x<path.length; x++)
+               fprintf(fd,"      %f,%f,5\n",(path.lon[x]<180.0?-path.lon[x]:360.0-path.lon[x]),path.lat[x]);
+
+       fprintf(fd,"    </coordinates>\n");
+       fprintf(fd,"   </LineString>\n");
+       fprintf(fd,"</Placemark>\n");
+
+       fprintf(fd,"<Placemark>\n");
+       fprintf(fd,"<name>Line-of-Sight Path</name>\n");
+       fprintf(fd,"  <visibility>1</visibility>\n");
+       fprintf(fd,"  <open>0</open>\n");
+       fprintf(fd,"  <Style>\n");
+       fprintf(fd,"    <LineStyle>\n");
+       fprintf(fd,"      <color>ff00ff00</color>\n");
+       fprintf(fd,"    </LineStyle>\n");
+       fprintf(fd,"    <PolyStyle>\n");
+       fprintf(fd,"       <color>7f00ff00</color>\n");
+       fprintf(fd,"    </PolyStyle>\n");
+       fprintf(fd,"  </Style>\n");
+       fprintf(fd,"  <LineString>\n");
+       fprintf(fd,"    <extrude>1</extrude>\n");
+       fprintf(fd,"    <tessellate>1</tessellate>\n");
+       fprintf(fd,"    <altitudeMode>relativeToGround</altitudeMode>\n");
+       fprintf(fd,"    <coordinates>\n");
+
+       /* Walk across the "path", indentifying obstructions along the way */
+
+       for (y=0; y<path.length; y++)
        {
-               fprintf(fd,"Antenna height above average terrain: %.2f feet\n\n",terrain);
+               distance=5280.0*path.distance[y];
+               tx_alt=earthradius+source.alt+path.elevation[0];
+               rx_alt=earthradius+destination.alt+path.elevation[y];
 
-               /* Display the average terrain between 2 and 10 miles
-                  from the transmitter site at azimuths of 0, 45, 90,
-                  135, 180, 225, 270, and 315 degrees. */
+               /* Calculate the cosine of the elevation of the
+                  transmitter as seen at the temp rx point. */
 
-               for (azi=0; azi<=315; azi+=45)
+               cos_xmtr_angle=((rx_alt*rx_alt)+(distance*distance)-(tx_alt*tx_alt))/(2.0*rx_alt*distance);
+
+               for (x=y, block=0; x>=0 && block==0; x--)
                {
-                       fprintf(fd,"Average terrain at %3d degrees azimuth: ",azi);
-                       terrain=AverageTerrain(xmtr,(double)azi,2.0,10.0);
+                       distance=5280.0*(path.distance[y]-path.distance[x]);
+                       test_alt=earthradius+path.elevation[x];
 
-                       if (terrain>-4999.0)
-                               fprintf(fd,"%.2f feet AMSL\n",terrain);
-                       else
-                               fprintf(fd,"No terrain\n");
+                       cos_test_angle=((rx_alt*rx_alt)+(distance*distance)-(test_alt*test_alt))/(2.0*rx_alt*distance);
+
+                       /* Compare these two angles to determine if
+                          an obstruction exists.  Since we're comparing
+                          the cosines of these angles rather than
+                          the angles themselves, the following "if"
+                          statement is reversed from what it would
+                          be if the actual angles were compared. */
+
+                       if (cos_xmtr_angle>cos_test_angle)
+                               block=1;
                }
+
+               if (block)
+                       fprintf(fd,"      %f,%f,-30\n",(path.lon[y]<180.0?-path.lon[y]:360.0-path.lon[y]),path.lat[y]);
+               else
+                       fprintf(fd,"      %f,%f,5\n",(path.lon[y]<180.0?-path.lon[y]:360.0-path.lon[y]),path.lat[y]);
        }
 
-       fprintf(fd,"\n---------------------------------------------------------------------------\n\n");
+       fprintf(fd,"    </coordinates>\n");
+       fprintf(fd,"  </LineString>\n");
+       fprintf(fd,"</Placemark>\n");
+
+       fprintf(fd,"    <LookAt>\n");
+       fprintf(fd,"      <longitude>%f</longitude>\n",(source.lon<180.0?-source.lon:360.0-source.lon));
+       fprintf(fd,"      <latitude>%f</latitude>\n",source.lat);
+       fprintf(fd,"      <range>300.0</range>\n");
+       fprintf(fd,"      <tilt>45.0</tilt>\n");
+       fprintf(fd,"      <heading>%f</heading>\n",azimuth);
+       fprintf(fd,"    </LookAt>\n");
+
+       fprintf(fd,"</Folder>\n");
+       fprintf(fd,"</kml>\n");
+
        fclose(fd);
-       fprintf(stdout,"\nSite analysis report written to: \"%s\"\n",report_name);
+
+       fprintf(stdout, "KML file written to: \"%s\"\n",report_name);
+
+       fflush(stdout);
 }
 
 int main(char argc, char *argv[])
 {
+       int             x, y, z=0, min_lat, min_lon, max_lat, max_lon,
+                       rxlat, rxlon, txlat, txlon, west_min, west_max,
+                       north_min, north_max;
 
-       int             x, y, z=0;
-       unsigned char   rxlat, rxlon, txlat, txlon, min_lat,
-                       min_lon, max_lat, max_lon, 
-                       coverage=0, LRmap=0,
-                       ext[20], terrain_plot=0,
+       unsigned char   coverage=0, LRmap=0, ext[20], terrain_plot=0,
                        elevation_plot=0, height_plot=0, 
                        longley_plot=0, cities=0, bfs=0, txsites=0,
-                       count, west_min, west_max, north_min, north_max,
-                       report='y';
+                       count, report='y', norm=0, topomap=0, geo=0,
+                       kml=0;
  
        char            mapfile[255], header[80], city_file[5][255], 
                        elevation_file[255], height_file[255], 
                        longley_file[255], terrain_file[255],
-                       string[255], rxfile[255],
-                       txfile[255], map=0, boundary_file[5][255];
+                       string[255], rxfile[255], *env=NULL,
+                       txfile[255], map=0, boundary_file[5][255],
+                       udt_file[255], rxsite=0, plo_filename[255],
+                       pli_filename[255], nf=0;
 
        double          altitude=0.0, altitudeLR=0.0, tx_range=0.0,
                        rx_range=0.0, deg_range=0.0, deg_limit,
-                       deg_range_lon, er_mult;
+                       deg_range_lon, er_mult, freq=0.0;
+
        struct          site tx_site[4], rx_site;
+
        FILE            *fd;
 
-       sprintf(header,"\n  --==[ SPLAT! v%s Terrain Analysis Software (c) 1997-2004 KD2BD ]==--\n\n", splat_version);
 
        if (argc==1)
        {
-               fprintf(stdout, "%sAvailable Options...\n\n\t-t txsite(s).qth (max of 4)\n\t-r rxsite.qth\n",header);
-               fprintf(stdout,"\t-c plot coverage area(s) of TX(s) based on an RX antenna at X feet AGL\n");
-               fprintf(stdout,"\t-L plot path loss map of TX based on an RX antenna at X feet AGL\n");
-               fprintf(stdout,"\t-s filename(s) of city/site file(s) to import (max of 5)\n");
-               fprintf(stdout,"\t-b filename(s) of cartographic boundary file(s) to import (max of 5)\n");
-               fprintf(stdout,"\t-p filename of terrain profile graph to plot\n");
-               fprintf(stdout,"\t-e filename of terrain elevation graph to plot\n");
-               fprintf(stdout,"\t-h filename of terrain height graph to plot\n");
-               fprintf(stdout,"\t-l filename of Longley-Rice graph to plot\n");
-               fprintf(stdout,"\t-o filename of topographic map to generate (.ppm)\n");
-               fprintf(stdout,"\t-d sdf file directory path (overrides path in ~/.splat_path file)\n");
-               fprintf(stdout,"\t-n no analysis, brief report\n\t-N no analysis, no report\n");
-               fprintf(stdout,"\t-m earth radius multiplier\n");
-               fprintf(stdout,"\t-R modify default range for -c or -L (miles)\n\n");
-
+               fprintf(stdout,"\n\t\t --==[ SPLAT! v%s Available Options... ]==--\n\n",splat_version);
+               fprintf(stdout,"       -t txsite(s).qth (max of 4)\n");
+               fprintf(stdout,"       -r rxsite.qth\n");
+               fprintf(stdout,"       -c plot coverage of TX(s) with an RX antenna at X feet/meters AGL\n");
+               fprintf(stdout,"       -L plot path loss map of TX based on an RX at X feet/meters AGL\n");
+               fprintf(stdout,"       -s filename(s) of city/site file(s) to import (5 max)\n");
+               fprintf(stdout,"       -b filename(s) of cartographic boundary file(s) to import (max of 5)\n");
+               fprintf(stdout,"       -p filename of terrain profile graph to plot\n");
+               fprintf(stdout,"       -e filename of terrain elevation graph to plot\n");
+               fprintf(stdout,"       -h filename of terrain height graph to plot\n");
+               fprintf(stdout,"       -H filename of normalized terrain height graph to plot\n");
+               fprintf(stdout,"       -l filename of Longley-Rice graph to plot\n");
+               fprintf(stdout,"       -o filename of topographic map to generate (.ppm)\n");
+               fprintf(stdout,"       -u filename of user-defined terrain file to import\n");
+               fprintf(stdout,"       -d sdf file directory path (overrides path in ~/.splat_path file)\n");
+               fprintf(stdout,"       -n no analysis, brief report\n");
+               fprintf(stdout,"       -N no analysis, no report\n");
+               fprintf(stdout,"       -m earth radius multiplier\n");
+               fprintf(stdout,"       -f frequency for Fresnel zone calculation (MHz)\n");
+               fprintf(stdout,"       -R modify default range for -c or -L (miles/kilometers)\n");
+               fprintf(stdout,"      -db maximum loss contour to display on path loss maps (80-230 dB)\n");
+               fprintf(stdout,"      -nf do not plot Fresnel zones in height plots\n");
+               fprintf(stdout,"     -plo filename of path-loss output file\n");
+               fprintf(stdout,"     -pli filename of path-loss input file\n");
+               fprintf(stdout,"     -udt filename of user defined terrain input file\n");
+               fprintf(stdout,"     -geo generate an Xastir .geo georeference file (with .ppm output)\n");
+               fprintf(stdout,"     -kml generate a Google Earth .kml file (for point-to-point links)\n");
+               fprintf(stdout,"  -metric employ metric rather than imperial units for all user I/O\n\n");
+
+               fprintf(stdout,"If that flew by too fast, consider piping the output through 'less':\n");
+               fprintf(stdout,"\n\tsplat | less\n\n");
                fprintf(stdout,"Type 'man splat', or see the documentation for more details.\n\n");
                fflush(stdout);
                return 1;
@@ -3506,6 +5410,7 @@ int main(char argc, char *argv[])
 
        y=argc-1;
 
+       metric=0;
        rxfile[0]=0;
        txfile[0]=0;
        string[0]=0;
@@ -3513,19 +5418,31 @@ int main(char argc, char *argv[])
        elevation_file[0]=0;
        terrain_file[0]=0;
        sdf_path[0]=0;
+       udt_file[0]=0;
        path.length=0;
-       rx_site.lat=0.0;
-       rx_site.lon=0.0;
+       LR.frq_mhz=0.0;
+       rx_site.lat=91.0;
+       rx_site.lon=361.0;
+       plo_filename[0]=0;
+       pli_filename[0]=0;
        earthradius=EARTHRADIUS;
 
+       sprintf(header,"\n\t\t--==[ Welcome To SPLAT! v%s ]==--\n\n", splat_version);
+
+       for (x=0; x<4; x++)
+       {
+               tx_site[x].lat=91.0;
+               tx_site[x].lon=361.0;
+       }
+
        for (x=0; x<MAXSLOTS; x++)
        {
-               dem[x].min_el=0;
-               dem[x].max_el=0;
-               dem[x].min_north=0;
-               dem[x].max_north=0;
-               dem[x].min_west=0;
-               dem[x].max_west=0;
+               dem[x].min_el=32768;
+               dem[x].max_el=-32768;
+               dem[x].min_north=90;
+               dem[x].max_north=-90;
+               dem[x].min_west=360;
+               dem[x].max_west=-1;
        }
 
        /* Scan for command line arguments */
@@ -3575,6 +5492,14 @@ int main(char argc, char *argv[])
                        map=1;
                }
 
+               if (strcmp(argv[x],"-u")==0)
+               {
+                       z=x+1;
+
+                       if (z<=y && argv[z][0] && argv[z][0]!='-')
+                               strncpy(udt_file,argv[z],253);
+               }
+
                if (strcmp(argv[x],"-c")==0)
                {
                        z=x+1;
@@ -3586,6 +5511,24 @@ int main(char argc, char *argv[])
                        }
                }
 
+               if (strcmp(argv[x],"-db")==0 || strcmp(argv[x],"-dB")==0)
+               {
+                       z=x+1;
+
+                       if (z<=y && argv[z][0] && argv[z][0]!='-')
+                       {
+                               sscanf(argv[z],"%d",&maxdB);
+
+                               maxdB=abs(maxdB);
+
+                               if (maxdB<80)
+                                       maxdB=80;
+
+                               if (maxdB>230)
+                                       maxdB=230;
+                       }                        
+               }
+
                if (strcmp(argv[x],"-p")==0)
                { 
                        z=x+1;
@@ -3608,7 +5551,7 @@ int main(char argc, char *argv[])
                        }
                }
 
-               if (strcmp(argv[x],"-h")==0)
+               if (strcmp(argv[x],"-h")==0 || strcmp(argv[x],"-H")==0)
                {
                        z=x+1;
 
@@ -3617,26 +5560,37 @@ int main(char argc, char *argv[])
                                strncpy(height_file,argv[z],253);
                                height_plot=1;
                        }
+
+                       if (strcmp(argv[x],"-H")==0)
+                               norm=1;
+                       else
+                               norm=0;
                }
 
                if (strcmp(argv[x],"-n")==0)
                {
-                       if (z<=y && argv[z][0] && argv[z][0]!='-')
-                       {
-                               report='n';
-                               map=1;
-                       }
+                       report='n';
+                       map=1;
                }
 
                if (strcmp(argv[x],"-N")==0)
                {
-                       if (z<=y && argv[z][0] && argv[z][0]!='-');
-                       {
-                               report='N';
-                               map=1;
-                       }
+                       report='N';
+                       map=1;
                }
 
+               if (strcmp(argv[x],"-metric")==0)
+                       metric=1;
+
+               if (strcmp(argv[x],"-geo")==0)
+                       geo=1;
+
+               if (strcmp(argv[x],"-kml")==0)
+                       kml=1;
+
+               if (strcmp(argv[x],"-nf")==0)
+                       nf=1;
+
                if (strcmp(argv[x],"-d")==0)
                {
                        z=x+1;
@@ -3658,6 +5612,7 @@ int main(char argc, char *argv[])
                                txsites++;
                                z++;
                        }
+
                        z--;
                }
 
@@ -3702,6 +5657,7 @@ int main(char argc, char *argv[])
                        {
                                strncpy(rxfile,argv[z],253);
                                rx_site=LoadQTH(rxfile);
+                               rxsite=1;
                        }
                }
 
@@ -3717,6 +5673,7 @@ int main(char argc, char *argv[])
                                cities++;
                                z++;
                        }
+
                        z--;
                }
 
@@ -3732,8 +5689,41 @@ int main(char argc, char *argv[])
                                bfs++;
                                z++;
                        }
+
                        z--;
                }
+               
+               if (strcmp(argv[x],"-f")==0)
+               {
+                       z=x+1;
+
+                       if (z<=y && argv[z][0] && argv[z][0]!='-')
+                       {
+                               sscanf(argv[z],"%lf",&freq);
+
+                               if (freq<20)
+                                       freq=20;
+
+                               if (freq>20e3)
+                                       freq=20e3;
+                       }                        
+               }
+
+               if (strcmp(argv[x],"-plo")==0)
+               {
+                       z=x+1;
+
+                       if (z<=y && argv[z][0] && argv[z][0]!='-')
+                               strncpy(plo_filename,argv[z],253);
+               }
+
+               if (strcmp(argv[x],"-pli")==0)
+               {
+                       z=x+1;
+
+                       if (z<=y && argv[z][0] && argv[z][0]!='-')
+                               strncpy(pli_filename,argv[z],253);
+               }
        }
 
        /* Perform some error checking on the arguments
@@ -3749,7 +5739,7 @@ int main(char argc, char *argv[])
 
        for (x=0, y=0; x<txsites; x++)
        {
-               if (tx_site[x].lat==0.0 && tx_site[x].lon==0.0)
+               if (tx_site[x].lat==91.0 && tx_site[x].lon==361.0)
                {
                        fprintf(stderr,"\n*** ERROR: Transmitter site #%d not found!",x+1);
                        y++;
@@ -3762,13 +5752,34 @@ int main(char argc, char *argv[])
                exit (-1);
        }
 
-       if ((coverage+LRmap)==0 && rx_site.lat==0.0 && rx_site.lon==0.0)
+       if ((coverage+LRmap+pli_filename[0])==0 && rx_site.lat==91.0 && rx_site.lon==361.0)
        {
-               fprintf(stderr,"\n%c*** ERROR: No receiver site found or specified!\n\n",7);
-               exit (-1);
+               if (max_range!=0.0 && txsites!=0)
+               {
+                       /* Plot topographic map of radius "max_range" */
+
+                       map=0;
+                       topomap=1;
+                       report='N';
+               }
+
+               else
+               {
+                       fprintf(stderr,"\n%c*** ERROR: No receiver site found or specified!\n\n",7);
+                       exit (-1);
+               }
        }
 
-       /* No errors were detected.  Whew!  :-) */
+       /* No major errors were detected.  Whew!  :-) */
+
+       /* Adjust input parameters if -metric option is used */
+
+       if (metric)
+       {
+               altitudeLR/=METERS_PER_FOOT;    /* meters --> feet */
+               max_range/=KM_PER_MILE;         /* kilometers --> miles */
+               altitude/=METERS_PER_FOOT;      /* meters --> feet */
+       }
 
        /* If no SDF path was specified on the command line (-d), check
           for a path specified in the $HOME/.splat_path file.  If the
@@ -3778,7 +5789,8 @@ int main(char argc, char *argv[])
 
        if (sdf_path[0]==0)
        {
-               sprintf(string,"%s/.splat_path",getenv("HOME"));
+               env=getenv("HOME");
+               sprintf(string,"%s/.splat_path",env);
                fd=fopen(string,"r");
 
                if (fd!=NULL)
@@ -3812,90 +5824,98 @@ int main(char argc, char *argv[])
        fprintf(stdout,"%s",header);
        fflush(stdout);
 
-       x=0;
-       y=0;
+       if (pli_filename[0])
+       {
+               y=LoadPLI(pli_filename);
 
-       min_lat=0;
-       max_lat=0;
-       min_lon=0;
-       max_lon=0;
+               for (x=0; x<txsites; x++)
+                       PlaceMarker(tx_site[x]);
 
-       rxlat=(unsigned char)floor(rx_site.lat);
-       rxlon=(unsigned char)floor(rx_site.lon);
+               if (rxsite)
+                       PlaceMarker(rx_site);
 
-       if (rxlat!=0)
-       {
-               if (min_lat==0)
-                       min_lat=rxlat;
+               if (bfs)
+               {
+                       for (x=0; x<bfs; x++)
+                               LoadBoundaries(boundary_file[x]);
+               }
 
-               else if (rxlat<min_lat)
-                       min_lat=rxlat;
-       }
+               if (cities)
+               {
+                       for (x=0; x<cities; x++)
+                               LoadCities(city_file[x]);
+               }
 
-       if (rxlon!=0)
-       {
-               if (min_lon==0)
-                       min_lon=rxlon;
+               WritePPMLR(mapfile,geo);
 
-               else if (rxlon<min_lon)
-                       min_lon=rxlon;
+               exit(0);
        }
 
-       if (rxlat>max_lat)
-               max_lat=rxlat;
+       x=0;
+       y=0;
+
+       min_lat=90;
+       max_lat=-90;
 
-       if (rxlon>max_lon)
-               max_lon=rxlon;
+       min_lon=(int)floor(tx_site[0].lon);
+       max_lon=(int)floor(tx_site[0].lon);
 
        for (y=0, z=0; z<txsites; z++)
        {
-               txlat=(unsigned char)floor(tx_site[z].lat);
-               txlon=(unsigned char)floor(tx_site[z].lon);
-
-               if (txlat!=0)
-               {
-                       if (min_lat==0)
-                               min_lat=txlat;
+               txlat=(int)floor(tx_site[z].lat);
+               txlon=(int)floor(tx_site[z].lon);
 
-                       else if (txlat<min_lat)
-                               min_lat=txlat;
-               }
-
-               if (txlon!=0)
-               {
-                       if (min_lon==0)
-                               min_lon=txlon;
-
-                       else if (txlon<min_lon)
-                               min_lon=txlon;
-               }
+               if (txlat<min_lat)
+                       min_lat=txlat;
 
                if (txlat>max_lat)
                        max_lat=txlat;
 
-               if (txlon>max_lon)
+               if (LonDiff(txlon,min_lon)<0.0)
+                       min_lon=txlon;
+
+               if (LonDiff(txlon,max_lon)>0.0)
                        max_lon=txlon;
        }
 
-       if (min_lat!=0 && min_lon!=0 && max_lat!=0 && max_lon!=0)
+       if (rxsite)
        {
-               for (y=min_lon; y<=max_lon; y++)
-                       for (x=min_lat; x<=max_lat; x++)
-                       {
-                               sprintf(string,"%u:%u:%u:%u",x, x+1, y, y+1);
-                               LoadSDF(string);
-                       }
+               rxlat=(int)floor(rx_site.lat);
+               rxlon=(int)floor(rx_site.lon);
+
+               if (rxlat<min_lat)
+                       min_lat=rxlat;
+
+               if (rxlat>max_lat)
+                       max_lat=rxlat;
+
+               if (LonDiff(rxlon,min_lon)<0.0)
+                       min_lon=rxlon;
+
+               if (LonDiff(rxlon,max_lon)>0.0)
+                       max_lon=rxlon;
        }
 
-       if (coverage)
+       /* Load the required SDF files */ 
+
+       LoadTopoData(max_lon, min_lon, max_lat, min_lat);
+
+       if (coverage | LRmap | topomap)
        {
+               if (LRmap)
+                       txsites=1;
+
                for (z=0; z<txsites; z++)
                {
                        /* "Ball park" estimates used to load any additional
                           SDF files required to conduct this analysis. */
 
                        tx_range=sqrt(1.5*(tx_site[z].alt+GetElevation(tx_site[z])));
-                       rx_range=sqrt(1.5*altitude);
+
+                       if (LRmap)
+                               rx_range=sqrt(1.5*altitudeLR);
+                       else
+                               rx_range=sqrt(1.5*altitude);
 
                        /* deg_range determines the maximum
                           amount of topo data we read */
@@ -3950,149 +5970,66 @@ int main(char argc, char *argv[])
                        if (deg_range_lon>deg_limit)
                                deg_range_lon=deg_limit;
 
-                       north_min=(unsigned char)floor(tx_site[z].lat-deg_range);
-                       north_max=(unsigned char)floor(tx_site[z].lat+deg_range);
-                       west_min=(unsigned char)floor(tx_site[z].lon-deg_range_lon);
-                       west_max=(unsigned char)floor(tx_site[z].lon+deg_range_lon);
-
-                       if (min_lat==0)
-                               min_lat=north_min;
-
-                       else if (north_min<min_lat)
-                               min_lat=north_min;
-
-                       if (min_lon==0)
-                               min_lon=west_min;
-
-                       else if (west_min<min_lon)
-                               min_lon=west_min;
-
-                       if (north_max>max_lat)
-                               max_lat=north_max;
-
-                       if (west_max>max_lon)
-                               max_lon=west_max;
-               }
-
-               if (min_lat!=0 && min_lon!=0 && max_lat!=0 && max_lon!=0)
-               {
-                       for (y=min_lon; y<=max_lon; y++)
-                               for (x=min_lat; x<=max_lat; x++)
-                               {
-                                       sprintf(string,"%u:%u:%u:%u",x, x+1, y, y+1);
-                                       LoadSDF(string);
-                               }
-               }
-       }
-
-       if (LRmap)
-       {
-               /* "Ball park" estimates used to load any additional
-                  SDF files required to conduct this analysis. */
-
-               tx_range=sqrt(1.5*(tx_site[0].alt+GetElevation(tx_site[0])));
-               rx_range=sqrt(1.5*altitudeLR);
 
-               /**
-               tx_range=sqrt(5.0*tx_site[0].alt);
-               rx_range=sqrt(5.0*altitudeLR);
-               **/
+                       north_min=(int)floor(tx_site[z].lat-deg_range);
+                       north_max=(int)floor(tx_site[z].lat+deg_range);
 
-               /* deg_range determines the maximum
-                  amount of topo data we read */
+                       west_min=(int)floor(tx_site[z].lon-deg_range_lon);
 
-               deg_range=(tx_range+rx_range)/69.0;
+                       while (west_min<0)
+                               west_min+=360;
 
-               /* max_range sets the maximum size of the
-                  analysis.  A small, non-zero amount can
-                  be used to shrink the size of the analysis
-                  and limit the amount of topo data read by
-                  SPLAT!  A very large number will only increase
-                  the width of the analysis, not the size of
-                  the map. */
+                       while (west_min>=360)
+                               west_min-=360;
 
-               if (max_range==0.0)
-                       max_range=tx_range+rx_range;
+                       west_max=(int)floor(tx_site[z].lon+deg_range_lon);
 
-               if (max_range<(tx_range+rx_range))
-                       deg_range=max_range/69.0;
+                       while (west_max<0)
+                               west_max+=360;
 
-               /* Prevent the demand for a really wide coverage
-                  from allocating more slots than are available
-                  in memory. */
+                       while (west_max>=360)
+                               west_max-=360;
 
-               switch (MAXSLOTS)
-               {
-                       case 2: deg_limit=0.25;
-                               break;
-
-                       case 4: deg_limit=0.5;
-                               break;
+                       if (north_min<min_lat)
+                               min_lat=north_min;
 
-                       case 9: deg_limit=1.0;
-                               break;
+                       if (north_max>max_lat)
+                               max_lat=north_max;
 
-                       case 16: deg_limit=2.0;
-                               break;
+                       if (LonDiff(west_min,min_lon)<0.0)
+                               min_lon=west_min;
 
-                       case 25: deg_limit=3.0;
+                       if (LonDiff(west_max,max_lon)>0.0)
+                               max_lon=west_max;
                }
 
-               if (tx_site[0].lat<70.0)
-                       deg_range_lon=deg_range/cos(deg2rad*tx_site[0].lat);
-               else
-                       deg_range_lon=deg_range/cos(deg2rad*70.0);
-
-               /* Correct for squares in degrees not being square in miles */  
-
-               if (deg_range>deg_limit)
-                       deg_range=deg_limit;
-
-               if (deg_range_lon>deg_limit)
-                       deg_range_lon=deg_limit;
-
-               north_min=(unsigned char)floor(tx_site[0].lat-deg_range);
-               north_max=(unsigned char)floor(tx_site[0].lat+deg_range);
-               west_min=(unsigned char)floor(tx_site[0].lon-deg_range_lon);
-               west_max=(unsigned char)floor(tx_site[0].lon+deg_range_lon);
+               /* Load any additional SDF files, if required */ 
 
-               if (min_lat==0)
-                       min_lat=north_min;
-
-               else if (north_min<min_lat)
-                       min_lat=north_min;
-
-               if (min_lon==0)
-                       min_lon=west_min;
-
-               else if (west_min<min_lon)
-                       min_lon=west_min;
+               LoadTopoData(max_lon, min_lon, max_lat, min_lat);
+       }
 
-               if (north_max>max_lat)
-                       max_lat=north_max;
+       if (udt_file[0])
+               LoadUDT(udt_file);
 
-               if (west_max>max_lon)
-                       max_lon=west_max;
+       if (mapfile[0] && topomap==0)
+               map=1;
 
-               if (min_lat!=0 && min_lon!=0 && max_lat!=0 && max_lon!=0)
-               {
-                       for (y=min_lon; y<=max_lon; y++)
-                               for (x=min_lat; x<=max_lat; x++)
-                               {
-                                       sprintf(string,"%u:%u:%u:%u",x, x+1, y, y+1);
-                                       LoadSDF(string);
-                               }
-               }
-       }
+       if (freq==0.0 && nf==0)
+               freq=LR.frq_mhz;
 
-       if (mapfile[0])
-               map=1;
+       else if (nf==1)
+               freq=0.0;
 
-       if (coverage)
+       if (coverage | LRmap)
        {
                for (x=0; x<txsites; x++)
                {
-                       PlotCoverage(tx_site[x],altitude);
+                       if (coverage)
+                               PlotCoverage(tx_site[x],altitude);
+
+                       if (LRmap)
+                               PlotLRMap(tx_site[x],altitudeLR,plo_filename);
+
                        PlaceMarker(tx_site[x]);
 
                        if (report!='N')
@@ -4102,18 +6039,7 @@ int main(char argc, char *argv[])
                map=1;
        }
 
-       else if (LRmap)
-       {
-               PlotLRMap(tx_site[0],altitudeLR);
-               PlaceMarker(tx_site[0]);
-
-               if (report!='N')
-                       SiteReport(tx_site[0]);
-               
-               map=1;
-       }
-
-       else       
+       if (coverage==0 && LRmap==0)       
        {
                PlaceMarker(rx_site);
 
@@ -4143,11 +6069,14 @@ int main(char argc, char *argv[])
                        }
 
                        if (report!='N')
-                               ObstructionReport(tx_site[x],rx_site,report);
+                               ObstructionReport(tx_site[x],rx_site,report,freq);
+
+                       if (kml)
+                               WriteKML(tx_site[x],rx_site);
                }
        }
 
-       if (map)
+       if (map | topomap)
        {
                if (bfs)
                {
@@ -4160,11 +6089,11 @@ int main(char argc, char *argv[])
                        for (x=0; x<cities; x++)
                                LoadCities(city_file[x]);
                }
-                               
-               if (!LRmap)
-                       WritePPM(mapfile);
+
+               if (LRmap)
+                       WritePPMLR(mapfile,geo);
                else
-                       WritePPMLR(mapfile);
+                       WritePPM(mapfile,geo);
        }
 
        if (terrain_plot)
@@ -4258,14 +6187,14 @@ int main(char argc, char *argv[])
                        for (count=0; count<txsites; count++)
                        {
                                sprintf(string,"%s-%c%s%c",height_file,'1'+count,ext,0);
-                               GraphHeight(tx_site[count],rx_site,string);
+                               GraphHeight(tx_site[count],rx_site,string,freq,norm);
                        }
                }
 
                else
-                       GraphHeight(tx_site[0],rx_site,height_file);
+                       GraphHeight(tx_site[0],rx_site,height_file,freq,norm);
        }
-
+       
        if (longley_plot)
        {
                if (txsites>1)
@@ -4301,3 +6230,4 @@ int main(char argc, char *argv[])
 
        return 0;
 }
+