--- /dev/null
+.TH SPLAT! 1 "16 September 2007" "KD2BD Software" "KD2BD Software"
+.SH NAME
+splat \- An RF \fBS\fPignal \fBP\fPropagation, \fBL\fPoss, \fBA\fPnd \fBT\fPerrain analysis tool
+.SH SYNOPSIS
+splat [-t \fItransmitter_site.qth\fP]
+[-r \fIreceiver_site.qth\fP]
+[-c \fIrx antenna height for LOS coverage analysis (feet/meters) (float)\fP]
+[-L \fIrx antenna height for Longley-Rice coverage analysis (feet/meters) (float)\fP]
+[-p \fIterrain_profile.ext\fP]
+[-e \fIelevation_profile.ext\fP]
+[-h \fIheight_profile.ext\fP]
+[-H \fInormalized_height_profile.ext\fP]
+[-l \fILongley-Rice_profile.ext\fP]
+[-o \fItopographic_map_filename.ppm\fP]
+[-b \fIcartographic_boundary_filename.dat\fP]
+[-s \fIsite/city_database.dat\fP]
+[-d \fIsdf_directory_path\fP]
+[-m \fIearth radius multiplier (float)\fP]
+[-f \fIfrequency (MHz) for Fresnel zone calculations (float)\fP]
+[-R \fImaximum coverage radius (miles/kilometers) (float)\fP]
+[-dB \fImaximum attenuation contour to display on path loss maps (80-230 dB)\fP]
+[-fz \fIFresnel zone clearance percentage (default = 60)\fP]
+[-plo \fIpath_loss_output_file.txt\fP]
+[-pli \fIpath_loss_input_file.txt\fP]
+[-udt \fIuser_defined_terrain_file.dat\fP]
+[-n]
+[-N]
+[-nf]
+[-ngs]
+[-geo]
+[-kml]
+[-metric]
+.SH DESCRIPTION
+\fBSPLAT!\fP is a powerful terrestrial RF propagation and terrain
+analysis tool for the spectrum between 20 MHz and 20 GHz.
+\fBSPLAT!\fP is free software, and is designed for operation on Unix
+and Linux-based workstations. Redistribution and/or modification
+is permitted under the terms of the GNU General Public License, Version 2,
+as published by the Free Software Foundation. Adoption of \fBSPLAT!\fP
+source code in proprietary or closed-source applications is a violation
+of this license and is \fBstrictly\fP forbidden.
+
+\fBSPLAT!\fP is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY, without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+.SH INTRODUCTION
+Applications of \fBSPLAT!\fP include the visualization, design, and
+link budget analysis of wireless Wide Area Networks (WANs), commercial
+and amateur radio communication systems above 20 MHz, microwave links,
+frequency coordination and interference studies, and the prediction
+of analog and digital terrestrial radio and television contour regions.
+
+\fBSPLAT!\fP provides RF site engineering data such as great circle
+distances and bearings between sites, antenna elevation angles (uptilt),
+depression angles (downtilt), antenna height above mean sea level,
+antenna height above average terrain, bearings, distances, and elevations
+to known obstructions, Longley-Rice path attenuation, and received signal
+strength. In addition, the minimum antenna height requirements needed to
+clear terrain, the first Fresnel zone, and any user-definable percentage
+of the first Fresnel zone are also provided.
+
+\fBSPLAT!\fP produces reports, graphs, and high resolution topographic
+maps that depict line-of-sight paths, and regional path loss and signal
+strength contours through which expected coverage areas of transmitters
+and repeater systems can be obtained. When performing line-of-sight
+and Longley-Rice analyses in situations where multiple transmitter or
+repeater sites are employed, \fBSPLAT!\fP determines individual and
+mutual areas of coverage within the network specified.
+
+Simply typing \fCsplat\fR on the command line will return a summary
+of \fBSPLAT!\fP's command line options:
+\fC
+
+ --==[ SPLAT! v1.2.1 Available Options... ]==--
+
+ -t txsite(s).qth (max of 4 with -c, max of 30 with -L)
+ -r rxsite.qth
+ -c plot coverage of TX(s) with an RX antenna at X feet/meters AGL
+ -L plot path loss map of TX based on an RX at X feet/meters AGL
+ -s filename(s) of city/site file(s) to import (5 max)
+ -b filename(s) of cartographic boundary file(s) to import (5 max)
+ -p filename of terrain profile graph to plot
+ -e filename of terrain elevation graph to plot
+ -h filename of terrain height graph to plot
+ -H filename of normalized terrain height graph to plot
+ -l filename of Longley-Rice graph to plot
+ -o filename of topographic map to generate (.ppm)
+ -u filename of user-defined terrain file to import
+ -d sdf file directory path (overrides path in ~/.splat_path file)
+ -m earth radius multiplier
+ -n do not plot LOS paths in .ppm maps
+ -N do not produce unnecessary site or obstruction reports
+ -f frequency for Fresnel zone calculation (MHz)
+ -R modify default range for -c or -L (miles/kilometers)
+ -db maximum loss contour to display on path loss maps (80-230 dB)
+ -nf do not plot Fresnel zones in height plots
+ -fz Fresnel zone clearance percentage (default = 60)
+ -ngs display greyscale topography as white in .ppm files
+ -erp override ERP in .lrp file (Watts)
+ -pli filename of path-loss input file
+ -plo filename of path-loss output file
+ -udt filename of user defined terrain input file
+ -kml generate Google Earth (.kml) compatible output
+ -geo generate an Xastir .geo georeference file (with .ppm output)
+-metric employ metric rather than imperial units for all user I/O
+\fR
+.SH INPUT FILES
+\fBSPLAT!\fP is a command-line driven application and reads input
+data through a number of data files. Some files are mandatory for
+successful execution of the program, while others are optional.
+Mandatory files include 3-arc second topography models in the
+form of SPLAT Data Files (SDF files), site location files (QTH
+files), and Longley-Rice model parameter files (LRP files).
+Optional files include city location files, cartographic boundary
+files, user-defined terrain files, path-loss input files, antenna
+radiation pattern files, and color definition files.
+.SH SPLAT DATA FILES
+\fBSPLAT!\fP imports topographic data in the form of SPLAT Data Files
+(SDFs). These files may be generated from a number of information sources.
+In the United States, SPLAT Data Files can be generated through U.S.
+Geological Survey Digital Elevation Models (DEMs) using the \fBusgs2sdf\fP
+utility included with \fBSPLAT!\fP. USGS Digital Elevation Models
+compatible with this utility may be downloaded from:
+\fIhttp://edcftp.cr.usgs.gov/pub/data/DEM/250/\fP.
+
+Significantly better resolution and accuracy can be obtained through
+the use of SRTM-3 Version 2 digital elevation models. These models are
+the product of the STS-99 Space Shuttle Radar Topography Mission, and
+are available for most populated regions of the Earth. SPLAT Data Files
+may be generated from SRTM data using the included \fBsrtm2sdf\fP utility.
+SRTM-3 Version 2 data may be obtained through anonymous FTP from:
+\fIftp://e0srp01u.ecs.nasa.gov:21/srtm/version2/\fP
+
+The \fBstrm2sdf\fP utility may also be used to convert 3-arc second SRTM
+data in Band Interleaved by Line (.BIL) format for use with \fBSPLAT!\fP.
+This data is available via the web at:
+\fIhttp://seamless.usgs.gov/website/seamless/\fP
+
+Band Interleaved by Line data must be downloaded in a very specific manner
+to be compatible with \fBsrtm2sdf\fP and \fBSPLAT!\fP. Please consult
+\fBsrtm2sdf\fP's documentation for instructions on downloading .BIL
+topographic data through the USGS's Seamless Web Site.
+
+Despite the higher accuracy that SRTM data has to offer, some voids
+in the data sets exist. When voids are detected, the \fBsrtm2sdf\fP
+utility replaces them with corresponding data found in existing SDF
+files (that were presumably created from earlier USGS data through the
+\fBusgs2sdf\fP utility). If USGS-derived SDF data is not available, voids
+are handled through adjacent pixel averaging, or direct replacement.
+
+SPLAT Data Files contain integer value topographic elevations (in meters)
+referenced to mean sea level for 1-degree by 1-degree regions of the
+earth with a resolution of 3-arc seconds. SDF files can be read in
+either standard format (\fI.sdf\fP) as generated by the \fBusgs2sdf\fP
+and \fBsrtm2sdf\fP utilities, or in bzip2 compressed format
+(\fI.sdf.bz2\fP). Since uncompressed files can be read slightly
+faster than files that have been compressed, \fBSPLAT!\fP searches for
+needed SDF data in uncompressed format first. If uncompressed data
+cannot be located, \fBSPLAT!\fP then searches for data in bzip2 compressed
+format. If no compressed SDF files can be found for the region requested,
+\fBSPLAT!\fP assumes the region is over water, and will assign an
+elevation of sea-level to these areas.
+
+This feature of \fBSPLAT!\fP makes it possible to perform path analysis
+not only over land, but also between coastal areas not represented by
+Digital Elevation Model data. However, this behavior of \fBSPLAT!\fP
+underscores the importance of having all the SDF files required for
+the region being analyzed if meaningful results are to be expected.
+.SH SITE LOCATION (QTH) FILES
+\fBSPLAT!\fP imports site location information of transmitter and receiver
+sites analyzed by the program from ASCII files having a \fI.qth\fP extension.
+QTH files contain the site's name, the site's latitude (positive if North
+of the equator, negative if South), the site's longitude (in degrees West,
+0 to 360 degrees, or degrees East 0 to -360 degrees), and the site's
+antenna height above ground level (AGL), each separated by a single
+line-feed character. The antenna height is assumed to be specified in
+feet unless followed by the letter \fIm\fP or the word \fImeters\fP in
+either upper or lower case. Latitude and longitude information may be
+expressed in either decimal format (74.6864) or degree, minute, second
+(DMS) format (74 41 11.0).
+
+For example, a site location file describing television station WNJT-DT,
+Trenton, NJ (\fIwnjt-dt.qth\fP) might read as follows:
+\fC
+ WNJT-DT
+ 40.2828
+ 74.6864
+ 990.00
+\fR
+Each transmitter and receiver site analyzed by \fBSPLAT!\fP must be
+represented by its own site location (QTH) file.
+.SH LONGLEY-RICE PARAMETER (LRP) FILES
+Longley-Rice parameter data files are required for \fBSPLAT!\fP to
+determine RF path loss in either point-to-point or area prediction
+mode. Longley-Rice model parameter data is read from files having
+the same base name as the transmitter site QTH file, but with a
+\fI.lrp\fP extension. \fBSPLAT!\fP LRP files share the following
+format (\fIwnjt-dt.lrp\fP):
+\fC
+ 15.000 ; Earth Dielectric Constant (Relative permittivity)
+ 0.005 ; Earth Conductivity (Siemens per meter)
+ 301.000 ; Atmospheric Bending Constant (N-units)
+ 647.000 ; Frequency in MHz (20 MHz to 20 GHz)
+ 5 ; Radio Climate (5 = Continental Temperate)
+ 0 ; Polarization (0 = Horizontal, 1 = Vertical)
+ 0.50 ; Fraction of situations (50% of locations)
+ 0.90 ; Fraction of time (90% of the time)
+ 46000.0 ; ERP in Watts (optional)
+\fR
+If an LRP file corresponding to the tx_site QTH file cannot
+be found, \fBSPLAT!\fP scans the current working directory for
+the file "splat.lrp". If this file cannot be found, then default
+parameters will be assigned by \fBSPLAT!\fP and a corresponding
+"splat.lrp" file containing these default parameters will be written
+to the current working directory. The generated "splat.lrp" file can
+then be edited by the user as needed.
+
+Typical Earth dielectric constants and conductivity values are as
+follows:
+\fC
+ Dielectric Constant Conductivity
+ Salt water : 80 5.000
+ Good ground : 25 0.020
+ Fresh water : 80 0.010
+ Marshy land : 12 0.007
+ Farmland, forest : 15 0.005
+ Average ground : 15 0.005
+ Mountain, sand : 13 0.002
+ City : 5 0.001
+ Poor ground : 4 0.001
+\fR
+Radio climate codes used by \fBSPLAT!\fP are as follows:
+\fC
+ 1: Equatorial (Congo)
+ 2: Continental Subtropical (Sudan)
+ 3: Maritime Subtropical (West coast of Africa)
+ 4: Desert (Sahara)
+ 5: Continental Temperate
+ 6: Maritime Temperate, over land (UK and west coasts of US & EU)
+ 7: Maritime Temperate, over sea
+\fR
+The Continental Temperate climate is common to large land masses in
+the temperate zone, such as the United States. For paths shorter than
+100 km, there is little difference between Continental and Maritime
+Temperate climates.
+
+The seventh and eighth parameters in the \fI.lrp\fP file correspond to the
+statistical analysis provided by the Longley-Rice model. In this example,
+\fBSPLAT!\fP will return the maximum path loss occurring 50% of the time
+(fraction of time) in 90% of situations (fraction of situations). This is
+often denoted as F(50,90) in Longley-Rice studies. In the United States,
+an F(50,90) criteria is typically used for digital television (8-level
+VSB modulation), while F(50,50) is used for analog (VSB-AM+NTSC) broadcasts.
+
+For further information on these parameters, see:
+\fIhttp://flattop.its.bldrdoc.gov/itm.html\fP and
+\fIhttp://www.softwright.com/faq/engineering/prop_longley_rice.html\fP
+
+The final parameter in the \fI.lrp\fP file corresponds to the transmitter's
+effective radiated power, and is optional. If it is included in the
+\fI.lrp\fP file, then \fBSPLAT!\fP will compute received signal strength
+levels and field strength level contours when performing Longley-Rice
+studies. If the parameter is omitted, path loss is computed instead.
+The ERP provided in the \fI.lrp\fP file can be overridden by using
+\fBSPLAT!\fP's \fI-erp\fP command-line switch. If the \fI.lrp\fP file
+contains an ERP parameter and the generation of path-loss rather than
+signal strength contours is desired, the ERP can be assigned to zero
+using the \fI-erp\fP switch without having to edit the \fI.lrp\fP file
+to accomplish the same result.
+.SH CITY LOCATION FILES
+The names and locations of cities, tower sites, or other points of interest
+may be imported and plotted on topographic maps generated by \fBSPLAT!\fP.
+\fBSPLAT!\fP imports the names of cities and locations from ASCII files
+containing the location of interest's name, latitude, and longitude.
+Each field is separated by a comma. Each record is separated by a
+single line feed character. As was the case with the \fI.qth\fP
+files, latitude and longitude information may be entered in either
+decimal or degree, minute, second (DMS) format.
+
+For example (\fIcities.dat\fP):
+\fC
+ Teaneck, 40.891973, 74.014506
+ Tenafly, 40.919212, 73.955892
+ Teterboro, 40.859511, 74.058908
+ Tinton Falls, 40.279966, 74.093924
+ Toms River, 39.977777, 74.183580
+ Totowa, 40.906160, 74.223310
+ Trenton, 40.219922, 74.754665
+\fR
+A total of five separate city data files may be imported at a time,
+and there is no limit to the size of these files. \fBSPLAT!\fP reads
+city data on a "first come/first served" basis, and plots only those
+locations whose annotations do not conflict with annotations of
+locations read earlier in the current city data file, or in previous
+files. This behavior minimizes clutter in \fBSPLAT!\fP generated
+topographic maps, but also mandates that important locations be placed
+toward the beginning of the first city data file, and locations less
+important be positioned further down the list or in subsequent data
+files.
+
+City data files may be generated manually using any text editor,
+imported from other sources, or derived from data available from the
+U.S. Census Bureau using the \fBcitydecoder\fP utility included with
+\fBSPLAT!\fP. Such data is available free of charge via the Internet
+at: \fIhttp://www.census.gov/geo/www/cob/bdy_files.html\fP, and must
+be in ASCII format.
+.SH CARTOGRAPHIC BOUNDARY DATA FILES
+Cartographic boundary data may also be imported to plot the boundaries of
+cities, counties, or states on topographic maps generated by \fBSPLAT!\fP.
+Such data must be of the form of ARC/INFO Ungenerate (ASCII Format)
+Metadata Cartographic Boundary Files, and are available from the U.S.
+Census Bureau via the Internet at:
+\fIhttp://www.census.gov/geo/www/cob/co2000.html#ascii\fP and
+\fIhttp://www.census.gov/geo/www/cob/pl2000.html#ascii\fP. A total of
+five separate cartographic boundary files may be imported at a time.
+It is not necessary to import state boundaries if county boundaries
+have already been imported.
+.SH PROGRAM OPERATION
+\fBSPLAT!\fP is invoked via the command-line using a series of switches
+and arguments. Since \fBSPLAT!\fP is a CPU and memory intensive application,
+this type of interface minimizes overhead and lends itself well to
+scripted (batch) operations. \fBSPLAT!\fP's CPU and memory scheduling
+priority may be modified through the use of the Unix \fBnice\fP command.
+
+The number and type of switches passed to \fBSPLAT!\fP determine its
+mode of operation and method of output data generation. Nearly all
+of \fBSPLAT!\fP's switches may be cascaded in any order on the command
+line when invoking the program.
+
+\fBSPLAT!\fP operates in two distinct modes: \fIpoint-to-point mode\fP,
+and \fIarea prediction mode\fP. Either a line-of-sight (LOS) or Longley-Rice
+Irregular Terrain (ITM) propagation model may be invoked by the user. True
+Earth, four-thirds Earth, or any other user-defined Earth radius may be
+specified when performing line-of-sight analysis.
+.SH POINT-TO-POINT ANALYSIS
+\fBSPLAT!\fP may be used to perform line-of-sight terrain analysis
+between two specified site locations. For example:
+
+\fCsplat -t tx_site.qth -r rx_site.qth\fR
+
+invokes a line-of-sight terrain analysis between the transmitter
+specified in \fItx_site.qth\fP and receiver specified in \fIrx_site.qth\fP
+using a True Earth radius model, and writes a \fBSPLAT!\fP Path Analysis
+Report to the current working directory. The report contains details of
+the transmitter and receiver sites, and identifies the location of any
+obstructions detected along the line-of-sight path. If an obstruction
+can be cleared by raising the receive antenna to a greater altitude,
+\fBSPLAT!\fP will indicate the minimum antenna height required for a
+line-of-sight path to exist between the transmitter and receiver locations
+specified. Note that imperial units (miles, feet) are specified unless
+the \fI-metric\fP switch is added to \fBSPLAT!\fP's command line options:
+
+\fCsplat -t tx_site.qth -r rx_site.qth -metric\fR
+
+If the antenna must be raised a significant amount, this determination
+may take a few moments. Note that the results provided are the \fIminimum\fP
+necessary for a line-of-sight path to exist, and in the case of this
+simple example, do not take Fresnel zone clearance requirements into
+consideration.
+
+\fIqth\fP extensions are assumed by \fBSPLAT!\fP for QTH files, and
+are optional when specifying -t and -r arguments on the command-line.
+\fBSPLAT!\fP automatically reads all SPLAT Data Files necessary to
+conduct the terrain analysis between the sites specified. \fBSPLAT!\fP
+searches for the required SDF files in the current working directory
+first. If the needed files are not found, \fBSPLAT!\fP then searches
+in the path specified by the \fI-d\fP command-line switch:
+
+\fCsplat -t tx_site -r rx_site -d /cdrom/sdf/\fR
+
+An external directory path may be specified by placing a ".splat_path"
+file under the user's home directory. This file must contain the full
+directory path of last resort to all the SDF files. The path in the
+\fI$HOME/.splat_path\fP file must be of the form of a single line of
+ASCII text:
+
+\fC/opt/splat/sdf/\fR
+
+and can be generated using any text editor.
+
+A graph of the terrain profile between the receiver and transmitter
+locations as a function of distance from the receiver can be generated
+by adding the \fI-p\fP switch:
+
+\fCsplat -t tx_site -r rx_site -p terrain_profile.png\fR
+
+\fBSPLAT!\fP invokes \fBgnuplot\fP when generating graphs. The filename
+extension specified to \fBSPLAT!\fP determines the format of the graph
+produced. \fI.png\fP will produce a 640x480 color PNG graphic file,
+while \fI.ps\fP or \fI.postscript\fP will produce postscript output.
+Output in formats such as GIF, Adobe Illustrator, AutoCAD dxf,
+LaTeX, and many others are available. Please consult \fBgnuplot\fP,
+and \fBgnuplot\fP's documentation for details on all the supported
+output formats.
+
+A graph of elevations subtended by the terrain between the receiver and
+transmitter as a function of distance from the receiver can be generated
+by using the \fI-e\fP switch:
+
+\fCsplat -t tx_site -r rx_site -e elevation_profile.png\fR
+
+The graph produced using this switch illustrates the elevation and
+depression angles resulting from the terrain between the receiver's
+location and the transmitter site from the perspective of the receiver's
+location. A second trace is plotted between the left side of the graph
+(receiver's location) and the location of the transmitting antenna on
+the right. This trace illustrates the elevation angle required for a
+line-of-sight path to exist between the receiver and transmitter
+locations. If the trace intersects the elevation profile at any point
+on the graph, then this is an indication that a line-of-sight path
+does not exist under the conditions given, and the obstructions can
+be clearly identified on the graph at the point(s) of intersection.
+
+A graph illustrating terrain height referenced to a line-of-sight
+path between the transmitter and receiver may be generated using
+the \fI-h\fP switch:
+
+\fCsplat -t tx_site -r rx_site -h height_profile.png\fR
+
+A terrain height plot normalized to the transmitter and receiver
+antenna heights can be obtained using the \fI-H\fP switch:
+
+\fCsplat -t tx_site -r rx_site -H normalized_height_profile.png\fR
+
+A contour of the Earth's curvature is also plotted in this mode.
+
+The first Fresnel Zone, and 60% of the first Fresnel Zone can be
+added to height profile graphs by adding the \fI-f\fP switch, and
+specifying a frequency (in MHz) at which the Fresnel Zone should be
+modeled:
+
+\fCsplat -t tx_site -r rx_site -f 439.250 -H normalized_height_profile.png\fR
+
+Fresnel Zone clearances other 60% can be specified using the \fI-fz\fP
+switch as follows:
+
+\fCsplat -t tx_site -r rx_site -f 439.250 -fz 75 -H height_profile2.png\fR
+
+A graph showing Longley-Rice path loss may be plotted using the
+\fI-l\fP switch:
+
+\fCsplat -t tx_site -r rx_site -l path_loss_profile.png\fR
+
+As before, adding the \fI-metric\fP switch forces the graphs to
+be plotted using metric units of measure.
+
+When performing a point-to-point analysis, a \fBSPLAT!\fP Path Analysis
+Report is generated in the form of a text file with a \fI.txt\fP filename
+extension. The report contains bearings and distances between the
+transmitter and receiver, as well as the free-space and Longley-Rice
+path loss for the path being analyzed. The mode of propagation for
+the path is given as \fILine-of-Sight\fP, \fISingle Horizon\fP,
+\fIDouble Horizon\fP, \fIDiffraction Dominant\fP, or \fITroposcatter
+Dominant\fP.
+
+Distances and locations to known obstructions along the path
+between transmitter and receiver are also provided. If the
+transmitter's effective radiated power is specified in the
+transmitter's corresponding \fI.lrp\fP file, then predicted
+signal strength and antenna voltage at the receiving location
+is also provided in the Path Analysis Report.
+
+To determine the signal-to-noise (SNR) ratio at remote location
+where random Johnson (thermal) noise is the primary limiting
+factor in reception:
+
+.EQ
+SNR = T - NJ - L + G - NF
+.EN
+
+where \fBT\fP is the ERP of the transmitter in dBW in the direction
+of the receiver, \fBNJ\fP is Johnson Noise in dBW (-136 dBW for a 6 MHz
+television channel), \fBL\fP is the path loss provided by \fBSPLAT!\fP
+in dB (as a \fIpositive\fP number), \fBG\fP is the receive antenna gain
+in dB over isotropic, and \fBNF\fP is the receiver noise figure in dB.
+
+\fBT\fP may be computed as follows:
+
+.EQ
+T = TI + GT
+.EN
+
+where \fBTI\fP is actual amount of RF power delivered to the transmitting
+antenna in dBW, \fBGT\fP is the transmitting antenna gain (over isotropic)
+in the direction of the receiver (or the horizon if the receiver is over
+the horizon).
+
+To compute how much more signal is available over the minimum to
+necessary to achieve a specific signal-to-noise ratio:
+
+.EQ
+Signal_Margin = SNR - S
+.EN
+
+where \fBS\fP is the minimum required SNR ratio (15.5 dB for
+ATSC (8-level VSB) DTV, 42 dB for analog NTSC television).
+
+A topographic map may be generated by \fBSPLAT!\fP to visualize the
+path between the transmitter and receiver sites from yet another
+perspective. Topographic maps generated by \fBSPLAT!\fP display
+elevations using a logarithmic grayscale, with higher elevations
+represented through brighter shades of gray. The dynamic range of
+the image is scaled between the highest and lowest elevations present
+in the map. The only exception to this is sea-level, which is
+represented using the color blue.
+
+Topographic output is invoked using the \fI-o\fP switch:
+
+\fCsplat -t tx_site -r rx_site -o topo_map.ppm\fR
+
+The \fI.ppm\fP extension on the output filename is assumed by
+\fBSPLAT!\fP, and is optional.
+
+In this example, \fItopo_map.ppm\fP will illustrate the locations of the
+transmitter and receiver sites specified. In addition, the great circle
+path between the two sites will be drawn over locations for which an
+unobstructed path exists to the transmitter at a receiving antenna
+height equal to that of the receiver site (specified in \fIrx_site.qth\fP).
+
+It may desirable to populate the topographic map with names and locations
+of cities, tower sites, or other important locations. A city file may be
+passed to \fBSPLAT!\fP using the \fI-s\fP switch:
+
+\fCsplat -t tx_site -r rx_site -s cities.dat -o topo_map\fR
+
+Up to five separate city files may be passed to \fBSPLAT!\fP at a time
+following the \fI-s\fP switch.
+
+County and state boundaries may be added to the map by specifying up
+to five U.S. Census Bureau cartographic boundary files using the \fI-b\fP
+switch:
+
+\fCsplat -t tx_site -r rx_site -b co34_d00.dat -o topo_map\fR
+
+In situations where multiple transmitter sites are in use, as many as
+four site locations may be passed to \fBSPLAT!\fP at a time for analysis:
+
+\fCsplat -t tx_site1 tx_site2 tx_site3 tx_site4 -r rx_site -p profile.png\fR
+
+In this example, four separate terrain profiles and obstruction reports
+will be generated by \fBSPLAT!\fP. A single topographic map can be
+specified using the \fI-o\fP switch, and line-of-sight paths between
+each transmitter and the receiver site indicated will be produced on
+the map, each in its own color. The path between the first transmitter
+specified to the receiver will be in green, the path between the
+second transmitter and the receiver will be in cyan, the path between
+the third transmitter and the receiver will be in violet, and the
+path between the fourth transmitter and the receiver will be in sienna.
+
+\fBSPLAT!\fP generated topographic maps are 24-bit TrueColor Portable
+PixMap (PPM) images. They may be viewed, edited, or converted to other
+graphic formats by popular image viewing applications such as \fBxv\fP,
+\fBThe GIMP\fP, \fBImageMagick\fP, and \fBXPaint\fP. PNG format is
+highly recommended for lossless compressed storage of \fBSPLAT!\fP
+generated topographic output files. \fBImageMagick\fP's command-line
+utility easily converts \fBSPLAT!\fP's PPM files to PNG format:
+
+\fCconvert splat_map.ppm splat_map.png\fR
+
+Another excellent PPM to PNG command-line utility is available
+at: \fIhttp://www.libpng.org/pub/png/book/sources.html\fP. As a last
+resort, PPM files may be compressed using the bzip2 utility, and read
+directly by \fBThe GIMP\fP in this format.
+
+The \fI-ngs\fP option assigns all terrain to the color white, and can be
+used when it is desirable to generate a map that is devoid of terrain:
+
+\fCsplat -t tx_site -r rx_site -b co34_d00.dat -ngs -o white_map\fR
+
+The resulting .ppm image file can be converted to .png format with a
+transparent background using \fBImageMagick\fP's \fBconvert\fP utility:
+
+\fCconvert -transparent "#FFFFFF" white_map.ppm transparent_map.png\fR
+.SH REGIONAL COVERAGE ANALYSIS
+\fBSPLAT!\fP can analyze a transmitter or repeater site, or network
+of sites, and predict the regional coverage for each site specified.
+In this mode, \fBSPLAT!\fP can generate a topographic map displaying
+the geometric line-of-sight coverage area of the sites based on the
+location of each site and the height of receive antenna wishing to
+communicate with the site in question. A regional analysis may be
+performed by \fBSPLAT!\fP using the \fI-c\fP switch as follows:
+
+\fCsplat -t tx_site -c 30.0 -s cities.dat -b co34_d00.dat -o tx_coverage\fR
+
+In this example, \fBSPLAT!\fP generates a topographic map called
+\fItx_coverage.ppm\fP that illustrates the predicted line-of-sight
+regional coverage of \fItx_site\fP to receiving locations having
+antennas 30.0 feet above ground level (AGL). If the \fI-metric\fP
+switch is used, the argument following the \fI-c\fP switch is
+interpreted as being in meters rather than in feet. The contents
+of \fIcities.dat\fP are plotted on the map, as are the cartographic
+boundaries contained in the file \fIco34_d00.dat\fP.
+
+When plotting line-of-sight paths and areas of regional coverage,
+\fBSPLAT!\fP by default does not account for the effects of
+atmospheric bending. However, this behavior may be modified
+by using the Earth radius multiplier (\fI-m\fP) switch:
+
+\fCsplat -t wnjt-dt -c 30.0 -m 1.333 -s cities.dat -b counties.dat -o map.ppm\fR
+
+An earth radius multiplier of 1.333 instructs \fBSPLAT!\fP to use
+the "four-thirds earth" model for line-of-sight propagation analysis.
+Any appropriate earth radius multiplier may be selected by the user.
+
+When performing a regional analysis, \fBSPLAT!\fP generates a
+site report for each station analyzed. \fBSPLAT!\fP site reports
+contain details of the site's geographic location, its height above
+mean sea level, the antenna's height above mean sea level, the
+antenna's height above average terrain, and the height of the
+average terrain calculated toward the bearings of 0, 45, 90, 135,
+180, 225, 270, and 315 degrees azimuth.
+.SH DETERMINING MULTIPLE REGIONS OF LOS COVERAGE
+\fBSPLAT!\fP can also display line-of-sight coverage areas for as
+many as four separate transmitter sites on a common topographic map.
+For example:
+
+\fCsplat -t site1 site2 site3 site4 -c 10.0 -metric -o network.ppm\fR
+
+plots the regional line-of-sight coverage of site1, site2, site3,
+and site4 based on a receive antenna located 10.0 meters above ground
+level. A topographic map is then written to the file \fInetwork.ppm\fP.
+The line-of-sight coverage area of the transmitters are plotted as
+follows in the colors indicated (along with their corresponding RGB
+values in decimal):
+\fC
+ site1: Green (0,255,0)
+ site2: Cyan (0,255,255)
+ site3: Medium Violet (147,112,219)
+ site4: Sienna 1 (255,130,71)
+
+ site1 + site2: Yellow (255,255,0)
+ site1 + site3: Pink (255,192,203)
+ site1 + site4: Green Yellow (173,255,47)
+ site2 + site3: Orange (255,165,0)
+ site2 + site4: Dark Sea Green 1 (193,255,193)
+ site3 + site4: Dark Turquoise (0,206,209)
+
+ site1 + site2 + site3: Dark Green (0,100,0)
+ site1 + site2 + site4: Blanched Almond (255,235,205)
+ site1 + site3 + site4: Medium Spring Green (0,250,154)
+ site2 + site3 + site4: Tan (210,180,140)
+
+ site1 + site2 + site3 + site4: Gold2 (238,201,0)
+\fR
+If separate \fI.qth\fP files are generated, each representing a common
+site location but a different antenna height, a single topographic map
+illustrating the regional coverage from as many as four separate locations
+on a single tower may be generated by \fBSPLAT!\fP.
+.SH LONGLEY-RICE PATH LOSS ANALYSIS
+If the \fI-c\fP switch is replaced by a \fI-L\fP switch, a
+Longley-Rice path loss map for a transmitter site may be generated:
+
+\fCsplat -t wnjt -L 30.0 -s cities.dat -b co34_d00.dat -o path_loss_map\fR
+
+In this mode, \fBSPLAT!\fP generates a multi-color map illustrating
+expected signal levels in areas surrounding the transmitter site. A
+legend at the bottom of the map correlates each color with a specific
+path loss range in decibels or signal strength in decibels over one
+microvolt per meter (dBuV/m).
+
+The Longley-Rice analysis range may be modified to a user-specific
+value using the \fI-R\fP switch. The argument must be given in miles
+(or kilometers if the \fI-metric\fP switch is used). If a range wider
+than the generated topographic map is specified, \fBSPLAT!\fP will
+perform Longley-Rice path loss calculations between all four corners
+of the area prediction map.
+
+The \fI-db\fP switch allows a constraint to be placed on the maximum
+path loss region plotted on the map. A maximum path loss between 80
+and 230 dB may be specified using this switch. For example, if a path
+loss beyond -140 dB is irrelevant to the survey being conducted,
+\fBSPLAT!\fP's path loss plot can be constrained to the region
+bounded by the 140 dB attenuation contour as follows:
+
+\fCsplat -t wnjt-dt -L 30.0 -s cities.dat -b co34_d00.dat -db 140 -o plot.ppm\fR
+
+.SH SIGNAL CONTOUR COLOR DEFINITION PARAMETERS
+The colors used to illustrate signal strength and path loss contours
+in \fBSPLAT!\fP generated coverage maps may be tailored by the user
+by creating or modifying \fBSPLAT!\fP's color definition files.
+\fBSPLAT!\fP color definition files have the same base name as the
+transmitter's \fI.qth\fP file, but carry \fI.lcf\fP and \fI.scf\fP
+extensions.
+
+When a regional Longley-Rice analysis is performed and the transmitter's
+ERP is not specified or is zero, a \fI.lcf\fP path loss color
+definition file corresponding to the transmitter site (\fI.qth\fP) is
+read by \fBSPLAT!\fP from the current working directory. If a \fI.lcf\fP
+file corresponding to the transmitter site is not found, then a default
+file suitable for manual editing by the user is automatically generated
+by \fBSPLAT!\fP. If the transmitter's ERP is specified, then a signal
+strength map is generated and a signal strength color definition file
+(\fI.scf\fP) is read, or generated if one is not available in the current
+working directory.
+
+A path-loss color definition file possesses the following structure
+(\fIwnjt-dt.lcf\fP):
+\fC
+ ; SPLAT! Auto-generated Path-Loss Color Definition ("wnjt-dt.lcf") File
+ ;
+ ; Format for the parameters held in this file is as follows:
+ ;
+ ; dB: red, green, blue
+ ;
+ ; ...where "dB" is the path loss (in dB) and
+ ; "red", "green", and "blue" are the corresponding RGB color
+ ; definitions ranging from 0 to 255 for the region specified.
+ ;
+ ; The following parameters may be edited and/or expanded
+ ; for future runs of SPLAT! A total of 32 contour regions
+ ; may be defined in this file.
+ ;
+ ;
+ 80: 255, 0, 0
+ 90: 255, 128, 0
+ 100: 255, 165, 0
+ 110: 255, 206, 0
+ 120: 255, 255, 0
+ 130: 184, 255, 0
+ 140: 0, 255, 0
+ 150: 0, 208, 0
+ 160: 0, 196, 196
+ 170: 0, 148, 255
+ 180: 80, 80, 255
+ 190: 0, 38, 255
+ 200: 142, 63, 255
+ 210: 196, 54, 255
+ 220: 255, 0, 255
+ 230: 255, 194, 204
+\fR
+
+If the path loss is less than 80 dB, the color Red (RGB = 255, 0, 0) is
+assigned to the region. If the path-loss is greater than or equal to
+80 dB, but less than 90 db, then Dark Orange (255, 128, 0) is assigned
+to the region. Orange (255, 165, 0) is assigned to regions having a
+path loss greater than or equal to 90 dB, but less than 100 dB, and
+so on. Greyscale terrain is displayed beyond the 230 dB path loss
+contour.
+
+\fBSPLAT!\fP signal strength color definition files share a very similar
+structure (\fIwnjt-dt.scf\fP):
+\fC
+ ; SPLAT! Auto-generated Signal Color Definition ("wnjt-dt.scf") File
+ ;
+ ; Format for the parameters held in this file is as follows:
+ ;
+ ; dBuV/m: red, green, blue
+ ;
+ ; ...where "dBuV/m" is the signal strength (in dBuV/m) and
+ ; "red", "green", and "blue" are the corresponding RGB color
+ ; definitions ranging from 0 to 255 for the region specified.
+ ;
+ ; The following parameters may be edited and/or expanded
+ ; for future runs of SPLAT! A total of 32 contour regions
+ ; may be defined in this file.
+ ;
+ ;
+ 128: 255, 0, 0
+ 118: 255, 165, 0
+ 108: 255, 206, 0
+ 98: 255, 255, 0
+ 88: 184, 255, 0
+ 78: 0, 255, 0
+ 68: 0, 208, 0
+ 58: 0, 196, 196
+ 48: 0, 148, 255
+ 38: 80, 80, 255
+ 28: 0, 38, 255
+ 18: 142, 63, 255
+ 8: 140, 0, 128
+\fR
+
+If the signal strength is greater than or equal to 128 db over 1 microvolt
+per meter (dBuV/m), the color Red (255, 0, 0) is displayed for the region.
+If the signal strength is greater than or equal to 118 dbuV/m, but less than
+128 dbuV/m, then the color Orange (255, 165, 0) is displayed, and so on.
+Greyscale terrain is displayed for regions with signal strengths less than
+8 dBuV/m.
+
+Signal strength contours for some common VHF and UHF broadcasting services
+in the United States are as follows:
+\fC
+ Analog Television Broadcasting
+ ------------------------------
+ Channels 2-6: City Grade: >= 74 dBuV/m
+ Grade A: >= 68 dBuV/m
+ Grade B: >= 47 dBuV/m
+ --------------------------------------------
+ Channels 7-13: City Grade: >= 77 dBuV/m
+ Grade A: >= 71 dBuV/m
+ Grade B: >= 56 dBuV/m
+ --------------------------------------------
+ Channels 14-69: Indoor Grade: >= 94 dBuV/m
+ City Grade: >= 80 dBuV/m
+ Grade A: >= 74 dBuV/m
+ Grade B: >= 64 dBuV/m
+
+ Digital Television Broadcasting
+ -------------------------------
+ Channels 2-6: City Grade: >= 35 dBuV/m
+ Service Threshold: >= 28 dBuV/m
+ --------------------------------------------
+ Channels 7-13: City Grade: >= 43 dBuV/m
+ Service Threshold: >= 36 dBuV/m
+ --------------------------------------------
+ Channels 14-69: City Grade: >= 48 dBuV/m
+ Service Threshold: >= 41 dBuV/m
+
+ NOAA Weather Radio (162.400 - 162.550 MHz)
+ ------------------------------------------
+ Reliable: >= 18 dBuV/m
+ Not reliable: < 18 dBuV/m
+ Unlikely to receive: < 0 dBuV/m
+
+ FM Radio Broadcasting (88.1 - 107.9 MHz)
+ ----------------------------------------
+ Analog Service Contour: 60 dBuV/m
+ Digital Service Contour: 65 dBuV/m
+\fR
+
+.SH ANTENNA RADIATION PATTERN PARAMETERS
+Normalized field voltage patterns for a transmitting antenna's horizontal
+and vertical planes are imported automatically into \fBSPLAT!\fP when a
+Longley-Rice coverage analysis is performed. Antenna pattern data is
+read from a pair of files having the same base name as the transmitter
+and LRP files, but with \fI.az\fP and \fI.el\fP extensions for azimuth
+and elevation pattern files, respectively. Specifications regarding
+pattern rotation (if any) and mechanical beam tilt and tilt direction
+(if any) are also contained within \fBSPLAT!\fP antenna pattern files.
+
+For example, the first few lines of a \fBSPLAT!\fP azimuth pattern file
+might appear as follows (\fIkvea.az\fP):
+\fC
+ 183.0
+ 0 0.8950590
+ 1 0.8966406
+ 2 0.8981447
+ 3 0.8995795
+ 4 0.9009535
+ 5 0.9022749
+ 6 0.9035517
+ 7 0.9047923
+ 8 0.9060051
+\fR
+The first line of the \fI.az\fP file specifies the amount of azimuthal
+pattern rotation (measured clockwise in degrees from True North) to be
+applied by \fBSPLAT!\fP to the data contained in the \fI.az\fP file.
+This is followed by azimuth headings (0 to 360 degrees) and their associated
+normalized field patterns (0.000 to 1.000) separated by whitespace.
+
+The structure of \fBSPLAT!\fP elevation pattern files is slightly different.
+The first line of the \fI.el\fP file specifies the amount of mechanical
+beam tilt applied to the antenna. Note that a \fIdownward tilt\fP
+(below the horizon) is expressed as a \fIpositive angle\fP, while an
+\fIupward tilt\fP (above the horizon) is expressed as a \fInegative angle\fP.
+This data is followed by the azimuthal direction of the tilt, separated by
+whitespace.
+
+The remainder of the file consists of elevation angles and their
+corresponding normalized voltage radiation pattern (0.000 to 1.000)
+values separated by whitespace. Elevation angles must be specified
+over a -10.0 to +90.0 degree range. As was the convention with mechanical
+beamtilt, \fInegative elevation angles\fP are used to represent elevations
+\fIabove the horizon\fP, while \fIpositive angles\fP represents elevations
+\fIbelow the horizon\fP.
+
+For example, the first few lines a \fBSPLAT!\fP elevation pattern file
+might appear as follows (\fIkvea.el\fP):
+\fC
+ 1.1 130.0
+ -10.0 0.172
+ -9.5 0.109
+ -9.0 0.115
+ -8.5 0.155
+ -8.0 0.157
+ -7.5 0.104
+ -7.0 0.029
+ -6.5 0.109
+ -6.0 0.185
+\fR
+In this example, the antenna is mechanically tilted downward 1.1 degrees
+towards an azimuth of 130.0 degrees.
+
+For best results, the resolution of azimuth pattern data should be
+specified to the nearest degree azimuth, and elevation pattern data
+resolution should be specified to the nearest 0.01 degrees. If the
+pattern data specified does not reach this level of resolution,
+\fBSPLAT!\fP will interpolate the values provided to determine the
+data at the required resolution, although this may result in a loss
+in accuracy.
+
+.SH IMPORTING AND EXPORTING REGIONAL PATH LOSS CONTOUR DATA
+Performing a Longley-Rice coverage analysis can be a very time
+consuming process, especially if the analysis is repeated repeatedly
+to discover what effects changes to the antenna radiation patterns
+make to the predicted coverage area.
+
+This process can be expedited by exporting the Longley-Rice
+regional path loss contour data to an output file, modifying the
+path loss data externally to incorporate antenna pattern effects,
+and then importing the modified path loss data back into \fBSPLAT!\fP
+to rapidly produce a revised path loss map.
+
+For example, a path loss output file can be generated by \fBSPLAT!\fP
+for a receive site 30 feet above ground level over a 50 mile radius
+surrounding a transmitter site to a maximum path loss of 140 dB using
+the following syntax:
+
+\fCsplat -t kvea -L 30.0 -R 50.0 -db 140 -plo pathloss.dat\fR
+
+\fBSPLAT!\fP path loss output files often exceed 100 megabytes in size.
+They contain information relating to the boundaries of region they describe
+followed by latitudes (degrees North), longitudes (degrees West), azimuths,
+elevations (to the first obstruction), and path loss figures (dB) for a
+series of specific points that comprise the region surrounding the
+transmitter site. The first few lines of a \fBSPLAT!\fP path loss
+output file take on the following appearance (\fIpathloss.dat\fP):
+\fC
+ 119, 117 ; max_west, min_west
+ 35, 33 ; max_north, min_north
+ 34.2265434, 118.0631104, 48.171, -37.461, 67.70
+ 34.2270355, 118.0624390, 48.262, -26.212, 73.72
+ 34.2280197, 118.0611038, 48.269, -14.951, 79.74
+ 34.2285156, 118.0604401, 48.207, -11.351, 81.68
+ 34.2290077, 118.0597687, 48.240, -10.518, 83.26
+ 34.2294998, 118.0591049, 48.225, 23.201, 84.60
+ 34.2304878, 118.0577698, 48.213, 15.769, 137.84
+ 34.2309799, 118.0570984, 48.234, 15.965, 151.54
+ 34.2314720, 118.0564346, 48.224, 16.520, 149.45
+ 34.2319679, 118.0557632, 48.223, 15.588, 151.61
+ 34.2329521, 118.0544281, 48.230, 13.889, 135.45
+ 34.2334442, 118.0537643, 48.223, 11.693, 137.37
+ 34.2339401, 118.0530930, 48.222, 14.050, 126.32
+ 34.2344322, 118.0524292, 48.216, 16.274, 156.28
+ 34.2354164, 118.0510941, 48.222, 15.058, 152.65
+ 34.2359123, 118.0504227, 48.221, 16.215, 158.57
+ 34.2364044, 118.0497589, 48.216, 15.024, 157.30
+ 34.2368965, 118.0490875, 48.225, 17.184, 156.36
+\fR
+It is not uncommon for \fBSPLAT!\fP path loss files to contain as
+many as 3 million or more lines of data. Comments can be placed in
+the file if they are proceeded by a semicolon character. The \fBvim\fP
+text editor has proven capable of editing files of this size.
+
+Note as was the case in the antenna pattern files, negative elevation
+angles refer to upward tilt (above the horizon), while positive angles
+refer to downward tilt (below the horizon). These angles refer to the
+elevation to the receiving antenna at the height above ground level
+specified using the \fI-L\fP switch \fIif\fP the path between transmitter
+and receiver is unobstructed. If the path between the transmitter
+and receiver is obstructed, then the elevation angle to the first
+obstruction is returned by \fBSPLAT!\fP. This is because
+the Longley-Rice model considers the energy reaching a distant point
+over an obstructed path as a derivative of the energy scattered from
+the top of the first obstruction, only. Since energy cannot reach
+the obstructed location directly, the actual elevation angle to that
+point is irrelevant.
+
+When modifying \fBSPLAT!\fP path loss files to reflect antenna
+pattern data, \fIonly the last column (path loss)\fP should be amended
+to reflect the antenna's normalized gain at the azimuth and elevation
+angles specified in the file. (At this time, programs and scripts
+capable of performing this operation are left as an exercise for
+the user.)
+
+Modified path loss maps can be imported back into \fBSPLAT!\fP for
+generating revised coverage maps:
+
+\fCsplat -t kvea -pli pathloss.dat -s city.dat -b county.dat -o map.ppm\fR
+
+\fBSPLAT!\fP path loss files can also be used for conducting coverage or
+interference studies outside of \fBSPLAT!\fP.
+.SH USER-DEFINED TERRAIN INPUT FILES
+A user-defined terrain file is a user-generated text file containing latitudes,
+longitudes, and heights above ground level of specific terrain features believed
+to be of importance to the \fBSPLAT!\fP analysis being conducted, but noticeably
+absent from the SDF files being used. A user-defined terrain file is imported
+into a \fBSPLAT!\fP analysis using the \fI-udt\fP switch:
+
+\fC splat -t tx_site -r rx_site -udt udt_file.txt -o map.ppm\fR
+
+A user-defined terrain file has the following appearance and structure:
+\fC
+ 40.32180556, 74.1325, 100.0 meters
+ 40.321805, 74.1315, 300.0
+ 40.3218055, 74.1305, 100.0 meters
+\fR
+Terrain height is interpreted as being described in feet above ground
+level unless followed by the word \fImeters\fP, and is added \fIon top of\fP
+the terrain specified in the SDF data for the locations specified. Be
+aware that each user-defined terrain feature specified will be interpreted
+as being 3-arc seconds in both latitude and longitude. Features described
+in the user-defined terrain file that overlap previously defined features
+in the file are ignored by \fBSPLAT!\fP.
+.SH SIMPLE TOPOGRAPHIC MAP GENERATION
+In certain situations it may be desirable to generate a topographic map
+of a region without plotting coverage areas, line-of-sight paths, or
+generating obstruction reports. There are several ways of doing this.
+If one wishes to generate a topographic map illustrating the location
+of a transmitter and receiver site along with a brief text report
+describing the locations and distances between the sites, the \fI-n\fP
+switch should be invoked as follows:
+
+\fCsplat -t tx_site -r rx_site -n -o topo_map.ppm\fR
+
+If no text report is desired, then the \fI-N\fP switch is used:
+
+\fCsplat -t tx_site -r rx_site -N -o topo_map.ppm\fR
+
+If a topographic map centered about a single site out to a minimum
+specified radius is desired instead, a command similar to the following
+can be used:
+
+\fCsplat -t tx_site -R 50.0 -s NJ_Cities -b NJ_Counties -o topo_map.ppm\fR
+
+where -R specifies the minimum radius of the map in miles (or kilometers
+if the \fI-metric\fP switch is used). Note that the tx_site name and
+location are not displayed in this example. If display of this information
+is desired, simply create a \fBSPLAT!\fP city file (\fI-s\fP option) and
+append it to the list of command-line options illustrated above.
+
+If the \fI-o\fP switch and output filename are omitted in these
+operations, topographic output is written to a file named \fItx_site.ppm\fP
+in the current working directory by default.
+.SH GEOREFERENCE FILE GENERATION
+Topographic, coverage (\fI-c\fP), and path loss contour (\fI-L\fP) maps
+generated by \fBSPLAT!\fP may be imported into \fBXastir\fP (X Amateur
+Station Tracking and Information Reporting) software by generating a
+georeference file using \fBSPLAT!\fP's \fI-geo\fP switch:
+
+\fCsplat -t kd2bd -R 50.0 -s NJ_Cities -b NJ_Counties -geo -o map.ppm\fR
+
+The georeference file generated will have the same base name as the
+\fI-o\fP file specified, but have a \fI .geo\fP extension, and permit
+proper interpretation and display of \fBSPLAT!\fP's .ppm graphics in
+\fBXastir\fP software.
+.SH GOOGLE MAP KML FILE GENERATION
+Keyhole Markup Language files compatible with \fBGoogle Earth\fP may
+be generated by \fBSPLAT!\fP when performing point-to-point or regional
+coverage analyses by invoking the \fI-kml\fP switch:
+
+\fCsplat -t wnjt-dt -r kd2bd -kml\fR
+
+The KML file generated will have the same filename structure as a
+Path Analysis Report for the transmitter and receiver site names given,
+except it will carry a \fI .kml\fP extension.
+
+Once loaded into \fBGoogle Earth\fP (File --> Open), the KML file
+will annotate the map display with the names of the transmitter and
+receiver site locations. The viewpoint of the image will be from the
+position of the transmitter site looking towards the location of the
+receiver. The point-to-point path between the sites will be displayed
+as a white line while the RF line-of-sight path will be displayed in
+green. \fBGoogle Earth\fP's navigation tools allow the user to
+"fly" around the path, identify landmarks, roads, and other
+featured content.
+
+When performing regional coverage analysis, the \fI .kml\fP file
+generated by \fBSPLAT!\fP will permit path loss or signal strength contours
+to be layered on top of \fBGoogle Earth\fP's display in a semi-transparent
+manner. The generated \fI.kml\fP file will have the same basename as
+that of the \fI.ppm\fP file normally generated.
+.SH DETERMINATION OF ANTENNA HEIGHT ABOVE AVERAGE TERRAIN
+\fBSPLAT!\fP determines antenna height above average terrain (HAAT)
+according to the procedure defined by Federal Communications Commission
+Part 73.313(d). According to this definition, terrain elevations along
+eight radials between 2 and 10 miles (3 and 16 kilometers) from the site
+being analyzed are sampled and averaged for each 45 degrees of azimuth
+starting with True North. If one or more radials lie entirely over water
+or over land outside the United States (areas for which no USGS topography
+data is available), then those radials are omitted from the calculation
+of average terrain.
+
+Note that SRTM elevation data, unlike older 3-arc second USGS data,
+extends beyond the borders of the United States. Therefore, HAAT
+results may not be in full compliance with FCC Part 73.313(d)
+in areas along the borders of the United States if the SDF files
+used by \fBSPLAT!\fP are SRTM-derived.
+
+When performing point-to-point terrain analysis, \fBSPLAT!\fP determines
+the antenna height above average terrain only if enough topographic
+data has already been loaded by the program to perform the point-to-point
+analysis. In most cases, this will be true, unless the site in question
+does not lie within 10 miles of the boundary of the topography data in
+memory.
+
+When performing area prediction analysis, enough topography data is
+normally loaded by \fBSPLAT!\fP to perform average terrain calculations.
+Under such conditions, \fBSPLAT!\fP will provide the antenna height
+above average terrain as well as the average terrain above mean sea
+level for azimuths of 0, 45, 90, 135, 180, 225, 270, and 315 degrees,
+and include such information in the generated site report. If one or
+more of the eight radials surveyed fall over water, or over regions
+for which no SDF data is available, \fBSPLAT!\fP reports \fINo Terrain\fP
+for the radial paths affected.
+.SH RESTRICTING THE MAXIMUM SIZE OF AN ANALYSIS REGION
+\fBSPLAT!\fP reads SDF files as needed into a series of memory "pages"
+within the structure of the program. Each "page" holds one SDF file
+representing a one degree by one degree region of terrain.
+A \fI#define MAXPAGES\fP statement in the first several lines of
+\fIsplat.cpp\fP sets the maximum number of "pages" available for holding
+topography data. It also sets the maximum size of the topographic maps
+generated by \fBSPLAT!\fP. MAXPAGES is set to 9 by default. If \fBSPLAT!\fP
+produces a segmentation fault on start-up with this default, it is an indication
+that not enough RAM and/or virtual memory (swap space) is available to
+run \fBSPLAT!\fP with the number of MAXPAGES specified. In situations where
+available memory is low, MAXPAGES may be reduced to 4 with the understanding
+that this will greatly limit the maximum region \fBSPLAT!\fP will be able
+to analyze. If 118 megabytes or more of total memory (swap space plus
+RAM) is available, then MAXPAGES may be increased to 16. This will
+permit operation over a 4-degree by 4-degree region, which is sufficient
+for single antenna heights in excess of 10,000 feet above mean sea
+level, or point-to-point distances of over 1000 miles.
+.SH ADDITIONAL INFORMATION
+The latest news and information regarding \fBSPLAT!\fP software is
+available through the official \fBSPLAT!\fP software web page located
+at: \fIhttp://www.qsl.net/kd2bd/splat.html\fP.
+.SH AUTHORS
+.TP
+John A. Magliacane, KD2BD <\fIkd2bd@amsat.org\fP>
+Creator, Lead Developer
+.TP
+Doug McDonald <\fImcdonald@scs.uiuc.edu\fP>
+Original Longley-Rice Model integration
+.TP
+Ron Bentley <\fIronbentley@earthlink.net\fP>
+Fresnel Zone plotting and clearance determination
+
projects / debian / splat / blobdiff