-SPLAT!(1) KD2BD Software SPLAT!(1)
+SPLAT!(1) KD2BD Software SPLAT!(1)
NAME
- splat - An RF Signal Propagation, Loss, And Terrain analy-
- sis tool
+ splat An RF Signal Propagation, Loss, And Terrain analysis tool
SYNOPSIS
- splat [-t transmitter_site.qth] [-r receiver_site.qth]
- [-c rx antenna height for LOS coverage analysis
- (feet/meters) (float)] [-L rx antenna height for Longley-
- Rice coverage analysis (feet/meters) (float)] [-p ter-
- rain_profile.ext] [-e elevation_profile.ext] [-h
- height_profile.ext] [-H normalized_height_profile.ext] [-l
- Longley-Rice_profile.ext] [-o topographic_map_file-
- name.ppm] [-b cartographic_boundary_filename.dat] [-s
- site/city_database.dat] [-d sdf_directory_path] [-m earth
- radius multiplier (float)] [-f frequency (MHz) for Fresnel
- zone calculations (float)] [-R maximum coverage radius
- (miles/kilometers) (float)] [-dB maximum attenuation con-
- tour to display on path loss maps (80-230 dB)] [-fz Fres-
- nel zone clearance percentage (default = 60)] [-plo
- path_loss_output_file.txt] [-pli path_loss_input_file.txt]
- [-udt user_defined_terrain_file.dat] [-n] [-N] [-nf]
- [-ngs] [-geo] [-kml] [-metric]
+ splat [-t transmitter_site.qth] [-r receiver_site.qth] [-c rx antenna
+ height for LOS coverage analysis (feet/meters) (float)] [-L rx antenna
+ height for Longley-Rice coverage analysis (feet/meters) (float)] [-p
+ terrain_profile.ext] [-e elevation_profile.ext] [-h height_profile.ext]
+ [-H normalized_height_profile.ext] [-l Longley-Rice_profile.ext] [-o
+ topographic_map_filename.ppm] [-b cartographic_boundary_filename.dat]
+ [-s site/city_database.dat] [-d sdf_directory_path] [-m earth radius
+ multiplier (float)] [-f frequency (MHz) for Fresnel zone calculations
+ (float)] [-R maximum coverage radius (miles/kilometers) (float)] [-dB
+ threshold beyond which contours will not be displayed] [-gc ground
+ clutter height (feet/meters) (float)] [-fz Fresnel zone clearance per-
+ centage (default = 60)] [-ano alphanumeric output file name] [-ani
+ alphanumeric input file name] [-udt user_defined_terrain_file.dat] [-n]
+ [-N] [-nf] [-dbm] [-ngs] [-geo] [-kml] [-gpsav] [-metric]
DESCRIPTION
- SPLAT! is a powerful terrestrial RF propagation and ter-
- rain analysis tool for the spectrum between 20 MHz and 20
- GHz. SPLAT! is free software, and is designed for opera-
- tion 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 SPLAT! source code
- in proprietary or closed-source applications is a viola-
- tion of this license and is strictly forbidden.
-
- SPLAT! is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY, without even the implied war-
- ranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR-
- POSE. See the GNU General Public License for more
- details.
+ SPLAT! is a powerful terrestrial RF propagation and terrain analysis
+ tool for the spectrum between 20 MHz and 20 GHz. SPLAT! is free soft-
+ ware, and is designed for operation on Unix and Linux-based worksta-
+ tions. 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 SPLAT! source code in proprietary or
+ closed-source applications is a violation of this license and is
+ strictly forbidden.
+
+ SPLAT! 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.
INTRODUCTION
- Applications of SPLAT! 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.
-
- SPLAT! provides RF site engineering data such as great
- circle distances and bearings between sites, antenna ele-
- vation 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.
-
- SPLAT! produces reports, graphs, and high resolution topo-
- graphic maps that depict line-of-sight paths, and regional
- path loss and signal strength contours through which
- expected coverage areas of transmitters and repeater sys-
- tems can be obtained. When performing line-of-sight and
- Longley-Rice analyses in situations where multiple trans-
- mitter or repeater sites are employed, SPLAT! determines
- individual and mutual areas of coverage within the network
- specified.
-
- Simply typing splat on the command line will return a sum-
- mary of SPLAT!'s command line options:
-
-
- --==[ 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/kilome-
- ters)
- -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
-
+ Applications of SPLAT! include the visualization, design, and link bud-
+ get analysis of wireless Wide Area Networks (WANs), commercial and ama-
+ teur radio communication systems above 20 MHz, microwave links, fre-
+ quency coordination and interference studies, and the prediction of
+ analog and digital terrestrial radio and television contour regions.
+
+ SPLAT! provides RF site engineering data such as great circle distances
+ and bearings between sites, antenna elevation angles (uptilt), depres-
+ sion 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 per-
+ centage of the first Fresnel zone are also provided.
+
+ SPLAT! 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, SPLAT! determines individual and mutual
+ areas of coverage within the network specified.
INPUT FILES
- SPLAT! 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.
+ SPLAT! is a command-line driven application and reads input data
+ through a number of data files. Some files are mandatory for success-
+ ful execution of the program, while others are optional. Mandatory
+ files include digital elevation 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.
SPLAT DATA FILES
- SPLAT! 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 usgs2sdf utility
- included with SPLAT!. USGS Digital Elevation Models com-
- patible with this utility may be downloaded from:
+ SPLAT! 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. Geo-
+ logical Survey Digital Elevation Models (DEMs) using the postdownload
+ and usgs2sdf utilities included with SPLAT!. USGS Digital Elevation
+ Models compatible with these utilities may be downloaded from:
http://edcftp.cr.usgs.gov/pub/data/DEM/250/.
- Significantly better resolution and accuracy can be
- obtained through the use of SRTM-3 Version 2 digital ele-
- vation 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
- srtm2sdf utility. SRTM-3 Version 2 data may be obtained
- through anonymous FTP from:
- ftp://e0srp01u.ecs.nasa.gov:21/srtm/version2/
-
- The strm2sdf utility may also be used to convert 3-arc
- second SRTM data in Band Interleaved by Line (.BIL) format
- for use with SPLAT!. This data is available via the web
- at: http://seamless.usgs.gov/website/seamless/
-
- Band Interleaved by Line data must be downloaded in a very
- specific manner to be compatible with srtm2sdf and SPLAT!.
- Please consult srtm2sdf'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 srtm2sdf utility replaces them with corre-
- sponding data found in existing SDF files (that were pre-
- sumably created from earlier USGS data through the
- usgs2sdf utility). If USGS-derived SDF data is not avail-
- able, voids are handled through adjacent pixel averaging,
- or direct replacement.
-
- SPLAT Data Files contain integer value topographic eleva-
- tions (in meters) referenced to mean sea level for
- 1-degree by 1-degree regions of the earth with a resolu-
- tion of 3-arc seconds. SDF files can be read in either
- standard format (.sdf) as generated by the usgs2sdf and
- srtm2sdf utilities, or in bzip2 compressed format
- (.sdf.bz2). Since uncompressed files can be read slightly
- faster than files that have been compressed, SPLAT!
- searches for needed SDF data in uncompressed format first.
- If uncompressed data cannot be located, SPLAT! then
- searches for data in bzip2 compressed format. If no com-
- pressed SDF files can be found for the region requested,
- SPLAT! assumes the region is over water, and will assign
- an elevation of sea-level to these areas.
-
- This feature of SPLAT! 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 SPLAT! underscores the impor-
- tance of having all the SDF files required for the region
- being analyzed if meaningful results are to be expected.
+ Significantly better resolution and accuracy can be obtained through
+ the use of SRTM Version 2 digital elevation models, especially when
+ supplemented by USGS-derived SDF data. These one-degree by one-degree
+ models are the product of the Space Shuttle STS-99 Radar Topography
+ Mission, and are available for most populated regions of the Earth.
+ SPLAT Data Files may be generated from 3 arc-second SRTM-3 data using
+ the included srtm2sdf utility. SRTM-3 Version 2 data may be obtained
+ through anonymous FTP from: ftp://e0srp01u.ecs.nasa.gov:21/srtm/ver-
+ sion2/SRTM3/
+
+ Note that SRTM filenames refer to the latitude and longitude of the
+ southwest corner of the topographic dataset contained within the file.
+ Therefore, the region of interest must lie north and east of the lati-
+ tude and longitude provided in the SRTM filename.
+
+ The srtm2sdf utility may also be used to convert 3-arc second SRTM data
+ in Band Interleaved by Line (.BIL) format for use with SPLAT!. This
+ data is available via the web at: http://seamless.usgs.gov/web-
+ site/seamless/
+
+ Band Interleaved by Line data must be downloaded in a very specific
+ manner to be compatible with srtm2sdf and SPLAT!. Please consult
+ srtm2sdf's documentation for instructions on downloading .BIL topo-
+ graphic data through the USGS's Seamless Web Site.
+
+ Even greater resolution and accuracy can be obtained by using 1 arc-
+ second SRTM-1 Version 2 topography data. This data is available for
+ the United States and its territories and possessions, and may be down-
+ loaded from: ftp://e0srp01u.ecs.nasa.gov:21/srtm/version2/SRTM1/
+
+ High resolution SDF files for use with SPLAT! HD may be generated from
+ data in this format using the srtm2sdf-hd utility.
+
+ Despite the higher accuracy that SRTM data has to offer, some voids in
+ the data sets exist. When voids are detected, the srtm2sdf and
+ srtm2sdf-hd utilities replace them with corresponding data found in
+ usgs2sdf generated SDF files. If USGS-derived SDF data is not avail-
+ able, 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. SDF files can be read by SPLAT! in either standard format
+ (.sdf) as generated directly by the usgs2sdf, srtm2sdf, and srtm2sdf-hd
+ utilities, or in bzip2 compressed format (.sdf.bz2). Since uncom-
+ pressed files can be read slightly faster than files that have been
+ compressed, SPLAT! searches for needed SDF data in uncompressed format
+ first. If uncompressed data cannot be located, SPLAT! then searches
+ for data in bzip2 compressed format. If no compressed SDF files can be
+ found for the region requested, SPLAT! assumes the region is over
+ water, and will assign an elevation of sea-level to these areas.
+
+ This feature of SPLAT! makes it possible to perform path analysis not
+ only over land, but also between coastal areas not represented by Digi-
+ tal Elevation Model data. However, this behavior of SPLAT! under-
+ scores the importance of having all the SDF files required for the
+ region being analyzed if meaningful results are to be expected.
SITE LOCATION (QTH) FILES
- SPLAT! imports site location information of transmitter
- and receiver sites analyzed by the program from ASCII
- files having a .qth 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 m or the word meters in
- either upper or lower case. Latitude and longitude infor-
- mation 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 (wnjt-dt.qth) might read as
- follows:
+ SPLAT! imports site location information of transmitter and receiver
+ sites analyzed by the program from ASCII files having a .qth 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 speci-
+ fied in feet unless followed by the letter m or the word meters 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 (wnjt-dt.qth) might read as follows:
WNJT-DT
40.2828
74.6864
990.00
- Each transmitter and receiver site analyzed by SPLAT! must
- be represented by its own site location (QTH) file.
+ Each transmitter and receiver site analyzed by SPLAT! must be repre-
+ sented by its own site location (QTH) file.
LONGLEY-RICE PARAMETER (LRP) FILES
- Longley-Rice parameter data files are required for SPLAT!
- 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 transmit-
- ter site QTH file, but with a format (wnjt-dt.lrp):
-
- 15.000 ; Earth Dielectric Constant (Relative per-
- mittivity)
+ Longley-Rice parameter data files are required for SPLAT! to determine
+ RF path loss, field strength, or received signal power level 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 .lrp extension. SPLAT! LRP files share the
+ following format (wnjt-dt.lrp):
+
+ 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 Temper-
- ate)
- 0 ; Polarization (0 = Horizontal, 1 = Verti-
- cal)
- 0.50 ; Fraction of situations (50% of loca-
- tions)
+ 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)
- If an LRP file corresponding to the tx_site QTH file can-
- not be found, SPLAT! scans the current working directory
- for the file "splat.lrp". If this file cannot be found,
- then default parameters will be assigned by SPLAT! and a
- corresponding "splat.lrp" file containing these default
- parameters will be written to the current working direc-
- tory. The generated "splat.lrp" file can then be edited
- by the user as needed.
+ If an LRP file corresponding to the tx_site QTH file cannot be found,
+ SPLAT! scans the current working directory for the file "splat.lrp".
+ If this file cannot be found, then default parameters will be assigned
+ by SPLAT! and a corresponding "splat.lrp" file containing these default
+ parameters will be written to the current working directory. The gen-
+ erated "splat.lrp" file can then be edited by the user as needed.
- Typical Earth dielectric constants and conductivity values
- are as follows:
-
- Dielectric Constant Conductiv-
- ity
+ Typical Earth dielectric constants and conductivity values are as fol-
+ lows:
+ Dielectric Constant Conductivity
Salt water : 80 5.000
Good ground : 25 0.020
Fresh water : 80 0.010
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)
+ 6: Maritime Temperate, over land (UK and west coasts of US &
+ EU)
7: Maritime Temperate, over sea
- 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 .lrp file corre-
- spond to the statistical analysis provided by the Longley-
- Rice model. In this example, SPLAT! will return the maxi-
- mum 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:
- http://flattop.its.bldrdoc.gov/itm.html and
- http://www.softwright.com/faq/engineering/prop_long-
- ley_rice.html
-
- The final parameter in the .lrp file corresponds to the
- transmitter's effective radiated power, and is optional.
- If it is included in the 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 .lrp file can be overridden by using
- SPLAT!'s -erp command-line switch. If the .lrp file con-
- tains 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 -erp switch without hav-
- ing to edit the .lrp file to accomplish the same result.
+ 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 Temper-
+ ate climates.
+
+ The seventh and eighth parameters in the .lrp file correspond to the
+ statistical analysis provided by the Longley-Rice model. In this exam-
+ ple, SPLAT! 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: http://flat-
+ top.its.bldrdoc.gov/itm.html and http://www.softwright.com/faq/engi-
+ neering/prop_longley_rice.html
+
+ The final parameter in the .lrp file corresponds to the transmitter's
+ effective radiated power, and is optional. If it is included in the
+ .lrp file, then SPLAT! 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 pro-
+ vided in the .lrp file can be overridden by using SPLAT!'s -erp com-
+ mand-line switch. If the .lrp file contains an ERP parameter and the
+ generation of path loss rather than field strength contours is desired,
+ the ERP can be assigned to zero using the -erp switch without having to
+ edit the .lrp file to accomplish the same result.
CITY LOCATION FILES
- The names and locations of cities, tower sites, or other
- points of interest may be imported and plotted on topo-
- graphic maps generated by SPLAT!. SPLAT! 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 sepa-
- rated by a single line feed character. As was the case
- with the .qth files, latitude and longitude information
- may be entered in either decimal or degree, minute, second
- (DMS) format.
+ The names and locations of cities, tower sites, or other points of
+ interest may be imported and plotted on topographic maps generated by
+ SPLAT!. SPLAT! imports the names of cities and locations from ASCII
+ files containing the location of interest's name, latitude, and longi-
+ tude. Each field is separated by a comma. Each record is separated by
+ a single line feed character. As was the case with the .qth files,
+ latitude and longitude information may be entered in either decimal or
+ degree, minute, second (DMS) format.
For example (cities.dat):
Totowa, 40.906160, 74.223310
Trenton, 40.219922, 74.754665
- 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. SPLAT! reads city data on a "first come/first
- served" basis, and plots only those locations whose anno-
- tations do not conflict with annotations of locations read
- earlier in the current city data file, or in previous
- files. This behavior minimizes clutter in SPLAT! gener-
- ated 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 fur-
- ther 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 cityde-
- coder utility included with SPLAT!. Such data is avail-
- able free of charge via the Internet at: http://www.cen-
- sus.gov/geo/www/cob/bdy_files.html, and must be in ASCII
+ 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. SPLAT! 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 SPLAT! 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 citydecoder utility included with SPLAT!.
+ Such data is available free of charge via the Internet at:
+ http://www.census.gov/geo/www/cob/bdy_files.html, and must be in ASCII
format.
CARTOGRAPHIC BOUNDARY DATA FILES
- Cartographic boundary data may also be imported to plot
- the boundaries of cities, counties, or states on topo-
- graphic maps generated by SPLAT!. 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: http://www.cen-
- sus.gov/geo/www/cob/co2000.html#ascii and http://www.cen-
- sus.gov/geo/www/cob/pl2000.html#ascii. 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.
+ Cartographic boundary data may also be imported to plot the boundaries
+ of cities, counties, or states on topographic maps generated by SPLAT!.
+ 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: http://www.cen-
+ sus.gov/geo/www/cob/co2000.html#ascii and http://www.cen-
+ sus.gov/geo/www/cob/pl2000.html#ascii. A total of five separate carto-
+ graphic boundary files may be imported at a time. It is not necessary
+ to import state boundaries if county boundaries have already been
+ imported.
PROGRAM OPERATION
- SPLAT! is invoked via the command-line using a series of
- switches and arguments. Since SPLAT! is a CPU and memory
- intensive application, this type of interface minimizes
- overhead and lends itself well to scripted (batch) opera-
- tions. SPLAT!'s CPU and memory scheduling priority may be
- modified through the use of the Unix nice command.
-
- The number and type of switches passed to SPLAT! determine
- its mode of operation and method of output data genera-
- tion. Nearly all of SPLAT!'s switches may be cascaded in
- any order on the command line when invoking the program.
-
- SPLAT! operates in two distinct modes: point-to-point
- mode, and area prediction mode. 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 spec-
- ified when performing line-of-sight analysis.
+ SPLAT! is invoked via the command-line using a series of switches and
+ arguments. Since SPLAT! is a CPU and memory intensive application,
+ this type of interface minimizes overhead and lends itself well to
+ scripted (batch) operations. SPLAT!'s CPU and memory scheduling prior-
+ ity may be modified through the use of the Unix nice command.
+
+ The number and type of switches passed to SPLAT! determine its mode of
+ operation and method of output data generation. Nearly all of SPLAT!'s
+ switches may be cascaded in any order on the command line when invoking
+ the program.
+
+ Simply typing splat on the command line will return a summary of
+ SPLAT!'s command line options:
+
+ --==[ SPLAT! v1.3.0 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 path loss 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 threshold beyond which contours will not be displayed
+ -nf do not plot Fresnel zones in height plots
+ -fz Fresnel zone clearance percentage (default = 60)
+ -gc ground clutter height (feet/meters)
+ -ngs display greyscale topography as white in .ppm files
+ -erp override ERP in .lrp file (Watts)
+ -ano name of alphanumeric output file
+ -ani name of alphanumeric input 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)
+ -dbm plot signal power level contours rather than field strength
+ -gpsav preserve gnuplot temporary working files after SPLAT! execution
+ -metric employ metric rather than imperial units for all user I/O
+
+ The command-line options for splat and splat-hd are identical.
+
+ SPLAT! operates in two distinct modes: point-to-point mode, and area
+ prediction mode. Either a line-of-sight (LOS) or Longley-Rice Irregu-
+ lar 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.
POINT-TO-POINT ANALYSIS
- SPLAT! may be used to perform line-of-sight terrain analy-
- sis between two specified site locations. For example:
+ SPLAT! may be used to perform line-of-sight terrain analysis between
+ two specified site locations. For example:
splat -t tx_site.qth -r rx_site.qth
- invokes a line-of-sight terrain analysis between the
- transmitter specified in tx_site.qth and receiver speci-
- fied in rx_site.qth using a True Earth radius model, and
- writes a SPLAT! Path Analysis Report to the current work-
- ing directory. The report contains details of the trans-
- mitter 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, SPLAT! 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 -metric switch is added to SPLAT!'s
- command line options:
+ invokes a line-of-sight terrain analysis between the transmitter speci-
+ fied in tx_site.qth and receiver specified in rx_site.qth using a True
+ Earth radius model, and writes a SPLAT! Path Analysis Report to the
+ current working directory. The report contains details of the trans-
+ mitter and receiver sites, and identifies the location of any obstruc-
+ tions detected along the line-of-sight path. If an obstruction can be
+ cleared by raising the receive antenna to a greater altitude, SPLAT!
+ 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 -metric
+ switch is added to SPLAT!'s command line options:
splat -t tx_site.qth -r rx_site.qth -metric
- If the antenna must be raised a significant amount, this
- determination may take a few moments. Note that the
- results provided are the minimum necessary for a line-of-
- sight path to exist, and in the case of this simple exam-
- ple, do not take Fresnel zone clearance requirements into
+ If the antenna must be raised a significant amount, this determination
+ may take a few moments. Note that the results provided are the minimum
+ 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.
- qth extensions are assumed by SPLAT! for QTH files, and
- are optional when specifying -t and -r arguments on the
- command-line. SPLAT! automatically reads all SPLAT Data
- Files necessary to conduct the terrain analysis between
- the sites specified. SPLAT! searches for the required
- SDF files in the current working directory first. If the
- needed files are not found, SPLAT! then searches in the
- path specified by the -d command-line switch:
+ qth extensions are assumed by SPLAT! for QTH files, and are optional
+ when specifying -t and -r arguments on the command-line. SPLAT! auto-
+ matically reads all SPLAT Data Files necessary to conduct the terrain
+ analysis between the sites specified. SPLAT! searches for the
+ required SDF files in the current working directory first. If the
+ needed files are not found, SPLAT! then searches in the path specified
+ by the -d command-line switch:
splat -t tx_site -r rx_site -d /cdrom/sdf/
- 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 $HOME/.splat_path
- file must be of the form of a single line of ASCII text:
+ 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
+ $HOME/.splat_path file must be of the form of a single line of ASCII
+ text:
/opt/splat/sdf/
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 -p switch:
+ 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 -p switch:
splat -t tx_site -r rx_site -p terrain_profile.png
- SPLAT! invokes gnuplot when generating graphs. The file-
- name extension specified to SPLAT! determines the format
- of the graph produced. .png will produce a 640x480 color
- PNG graphic file, while .ps or .postscript will produce
- postscript output. Output in formats such as GIF, Adobe
- Illustrator, AutoCAD dxf, LaTeX, and many others are
- available. Please consult gnuplot, and gnuplot's documen-
- tation for details on all the supported output formats.
+ SPLAT! invokes gnuplot when generating graphs. The filename extension
+ specified to SPLAT! determines the format of the graph produced. .png
+ will produce a 640x480 color PNG graphic file, while .ps or .postscript
+ will produce postscript output. Output in formats such as GIF, Adobe
+ Illustrator, AutoCAD dxf, LaTeX, and many others are available. Please
+ consult gnuplot, and gnuplot'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 -e switch:
+ A graph of elevations subtended by the terrain between the receiver and
+ transmitter as a function of distance from the receiver can be gener-
+ ated by using the -e switch:
splat -t tx_site -r rx_site -e elevation_profile.png
- The graph produced using this switch illustrates the ele-
- vation 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 eleva-
- tion 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 -h switch:
+ 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 obstruc-
+ tions can be clearly identified on the graph at the point(s) of inter-
+ section.
+
+ A graph illustrating terrain height referenced to a line-of-sight path
+ between the transmitter and receiver may be generated using the -h
+ switch:
splat -t tx_site -r rx_site -h height_profile.png
- A terrain height plot normalized to the transmitter and
- receiver antenna heights can be obtained using the -H
- switch:
+ A terrain height plot normalized to the transmitter and receiver
+ antenna heights can be obtained using the -H switch:
- splat -t tx_site -r rx_site -H normalized_height_pro-
- file.png
+ splat -t tx_site -r rx_site -H normalized_height_profile.png
- A contour of the Earth's curvature is also plotted in this
- mode.
+ 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 -f
- switch, and specifying a frequency (in MHz) at which the
- Fresnel Zone should be modeled:
+ The first Fresnel Zone, and 60% of the first Fresnel Zone can be added
+ to height profile graphs by adding the -f switch, and specifying a fre-
+ quency (in MHz) at which the Fresnel Zone should be modeled:
- splat -t tx_site -r rx_site -f 439.250 -H normal-
- ized_height_profile.png
+ splat -t tx_site -r rx_site -f 439.250 -H normalized_height_profile.png
- Fresnel Zone clearances other 60% can be specified using
- the -fz switch as follows:
+ Fresnel Zone clearances other 60% can be specified using the -fz switch
+ as follows:
- splat -t tx_site -r rx_site -f 439.250 -fz 75 -H
- height_profile2.png
+ splat -t tx_site -r rx_site -f 439.250 -fz 75 -H height_profile2.png
- A graph showing Longley-Rice path loss may be plotted
- using the -l switch:
+ A graph showing Longley-Rice path loss may be plotted using the -l
+ switch:
splat -t tx_site -r rx_site -l path_loss_profile.png
- As before, adding the -metric switch forces the graphs to
- be plotted using metric units of measure.
-
- When performing a point-to-point analysis, a SPLAT! Path
- Analysis Report is generated in the form of a text file
- with a .txt filename extension. The report contains bear-
- ings 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 Line-of-Sight, Single Horizon, Double
- Horizon, Diffraction Dominant, or Troposcatter Dominant.
-
- 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 .lrp file, then pre-
- dicted signal strength and antenna voltage at the receiv-
- ing 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 pri-
- mary limiting factor in reception:
+ As before, adding the -metric switch forces the graphs to be plotted
+ using metric units of measure. The -gpsav switch instructs SPLAT! to
+ preserve (rather than delete) the gnuplot working files generated dur-
+ ing SPLAT! execution, allowing the user to edit these files and re-run
+ gnuplot if desired.
+
+ When performing a point-to-point analysis, a SPLAT! Path Analysis
+ Report is generated in the form of a text file with a .txt 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 Line-of-Sight, Single Horizon, Double Horizon,
+ Diffraction Dominant, or Troposcatter Dominant.
+
+ 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 correspond-
+ ing .lrp 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 recep-
+ tion:
SNR=T-NJ-L+G-NF
- where T is the ERP of the transmitter in dBW in the direc-
- tion of the receiver, NJ is Johnson Noise in dBW (-136 dBW
- for a 6 MHz television channel), L is the path loss pro-
- vided by SPLAT! in dB (as a positive number), G is the
- receive antenna gain in dB over isotropic, and NF is the
- receiver noise figure in dB.
+ where T is the ERP of the transmitter in dBW in the direction of the
+ receiver, NJ is Johnson Noise in dBW (-136 dBW for a 6 MHz television
+ channel), L is the path loss provided by SPLAT! in dB (as a positive
+ number), G is the receive antenna gain in dB over isotropic, and NF is
+ the receiver noise figure in dB.
T may be computed as follows:
T=TI+GT
- where TI is actual amount of RF power delivered to the
- transmitting antenna in dBW, GT is the transmitting
- antenna gain (over isotropic) in the direction of the
- receiver (or the horizon if the receiver is over the hori-
- zon).
+ where TI is actual amount of RF power delivered to the transmitting
+ antenna in dBW, GT 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 min-
- imum to necessary to achieve a specific signal-to-noise
- ratio:
+ To compute how much more signal is available over the minimum to neces-
+ sary to achieve a specific signal-to-noise ratio:
Signal_Margin=SNR-S
- where S is the minimum required SNR ratio (15.5 dB for
- ATSC (8-level VSB) DTV, 42 dB for analog NTSC television).
+ where S 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 SPLAT! to visualize
- the path between the transmitter and receiver sites from
- yet another perspective. Topographic maps generated by
- SPLAT! 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.
+ A topographic map may be generated by SPLAT! to visualize the path
+ between the transmitter and receiver sites from yet another perspec-
+ tive. Topographic maps generated by SPLAT! 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 -o switch:
splat -t tx_site -r rx_site -o topo_map.ppm
- The .ppm extension on the output filename is assumed by
- SPLAT!, and is optional.
+ The .ppm extension on the output filename is assumed by SPLAT!, and is
+ optional.
- In this example, topo_map.ppm will illustrate the loca-
- tions 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
- rx_site.qth).
+ In this example, topo_map.ppm will illustrate the locations of the
+ transmitter and receiver sites specified. In addition, the great cir-
+ cle 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 rx_site.qth).
- 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 SPLAT!
- using the -s switch:
+ It may desirable to populate the topographic map with names and loca-
+ tions of cities, tower sites, or other important locations. A city
+ file may be passed to SPLAT! using the -s switch:
splat -t tx_site -r rx_site -s cities.dat -o topo_map
- Up to five separate city files may be passed to SPLAT! at
- a time following the -s switch.
+ Up to five separate city files may be passed to SPLAT! at a time fol-
+ lowing the -s 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 -b 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 -b
+ switch:
splat -t tx_site -r rx_site -b co34_d00.dat -o topo_map
- In situations where multiple transmitter sites are in use,
- as many as four site locations may be passed to SPLAT! at
- a time for analysis:
-
- splat -t tx_site1 tx_site2 tx_site3 tx_site4 -r rx_site -p
- profile.png
-
- In this example, four separate terrain profiles and
- obstruction reports will be generated by SPLAT!. A single
- topographic map can be specified using the -o 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.
-
- SPLAT! 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 xv, The GIMP, ImageMagick,
- and XPaint. PNG format is highly recommended for lossless
- compressed storage of SPLAT! generated topographic output
- files. ImageMagick's command-line utility easily converts
- SPLAT!'s PPM files to PNG format:
+ In situations where multiple transmitter sites are in use, as many as
+ four site locations may be passed to SPLAT! at a time for analysis:
+
+ splat -t tx_site1 tx_site2 tx_site3 tx_site4 -r rx_site -p profile.png
+
+ In this example, four separate terrain profiles and obstruction reports
+ will be generated by SPLAT!. A single topographic map can be specified
+ using the -o 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.
+
+ SPLAT! 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 xv, The
+ GIMP, ImageMagick, and XPaint. PNG format is highly recommended for
+ lossless compressed storage of SPLAT! generated topographic output
+ files. ImageMagick's command-line utility easily converts SPLAT!'s PPM
+ files to PNG format:
convert splat_map.ppm splat_map.png
- Another excellent PPM to PNG command-line utility is
- available at:
- http://www.libpng.org/pub/png/book/sources.html. As a
- last resort, PPM files may be compressed using the bzip2
- utility, and read directly by The GIMP in this format.
+ Another excellent PPM to PNG command-line utility is available at:
+ http://www.libpng.org/pub/png/book/sources.html. As a last resort, PPM
+ files may be compressed using the bzip2 utility, and read directly by
+ The GIMP in this format.
- The -ngs 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:
+ The -ngs 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:
- splat -t tx_site -r rx_site -b co34_d00.dat -ngs -o
- white_map
+ splat -t tx_site -r rx_site -b co34_d00.dat -ngs -o white_map
- The resulting .ppm image file can be converted to .png
- format with a transparent background using ImageMagick's
- convert utility:
+ The resulting .ppm image file can be converted to .png format with a
+ transparent background using ImageMagick's convert utility:
- convert -transparent "#FFFFFF" white_map.ppm transpar-
- ent_map.png
+ convert -transparent "#FFFFFF" white_map.ppm transparent_map.png
REGIONAL COVERAGE ANALYSIS
- SPLAT! can analyze a transmitter or repeater site, or net-
- work of sites, and predict the regional coverage for each
- site specified. In this mode, SPLAT! can generate a topo-
- graphic map displaying the geometric line-of-sight cover-
- age 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 SPLAT! using the -c switch as follows:
-
- splat -t tx_site -c 30.0 -s cities.dat -b co34_d00.dat -o
- tx_coverage
-
- In this example, SPLAT! generates a topographic map called
- tx_coverage.ppm that illustrates the predicted line-of-
- sight regional coverage of tx_site to receiving locations
- having antennas 30.0 feet above ground level (AGL). If
- the -metric switch is used, the argument following the -c
- switch is interpreted as being in meters rather than in
- feet. The contents of cities.dat are plotted on the map,
- as are the cartographic boundaries contained in the file
- co34_d00.dat.
-
- When plotting line-of-sight paths and areas of regional
- coverage, SPLAT! by default does not account for the
- effects of atmospheric bending. However, this behavior
- may be modified by using the Earth radius multiplier (-m)
- switch:
-
- splat -t wnjt-dt -c 30.0 -m 1.333 -s cities.dat -b coun-
- ties.dat -o map.ppm
+ SPLAT! can analyze a transmitter or repeater site, or network of sites,
+ and predict the regional coverage for each site specified. In this
+ mode, SPLAT! 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 SPLAT! using
+ the -c switch as follows:
+
+ splat -t tx_site -c 30.0 -s cities.dat -b co34_d00.dat -o tx_coverage
+
+ In this example, SPLAT! generates a topographic map called tx_cover-
+ age.ppm that illustrates the predicted line-of-sight regional coverage
+ of tx_site to receiving locations having antennas 30.0 feet above
+ ground level (AGL). If the -metric switch is used, the argument fol-
+ lowing the -c switch is interpreted as being in meters rather than in
+ feet. The contents of cities.dat are plotted on the map, as are the
+ cartographic boundaries contained in the file co34_d00.dat.
+
+ When plotting line-of-sight paths and areas of regional coverage,
+ SPLAT! by default does not account for the effects of atmospheric bend-
+ ing. However, this behavior may be modified by using the Earth radius
+ multiplier (-m) switch:
+
+ splat -t wnjt-dt -c 30.0 -m 1.333 -s cities.dat -b counties.dat -o
+ map.ppm
- An earth radius multiplier of 1.333 instructs SPLAT! to
- use the "four-thirds earth" model for line-of-sight propa-
- gation analysis. Any appropriate earth radius multiplier
- may be selected by the user.
+ An earth radius multiplier of 1.333 instructs SPLAT! to use the "four-
+ thirds earth" model for line-of-sight propagation analysis. Any appro-
+ priate earth radius multiplier may be selected by the user.
- When performing a regional analysis, SPLAT! generates a
- site report for each station analyzed. SPLAT! 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.
+ When performing a regional analysis, SPLAT! generates a site report for
+ each station analyzed. SPLAT! 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 aver-
+ age terrain, and the height of the average terrain calculated toward
+ the bearings of 0, 45, 90, 135, 180, 225, 270, and 315 degrees azimuth.
DETERMINING MULTIPLE REGIONS OF LOS COVERAGE
- SPLAT! can also display line-of-sight coverage areas for
- as many as four separate transmitter sites on a common
- topographic map. For example:
+ SPLAT! can also display line-of-sight coverage areas for as many as
+ four separate transmitter sites on a common topographic map. For exam-
+ ple:
- splat -t site1 site2 site3 site4 -c 10.0 -metric -o net-
- work.ppm
+ splat -t site1 site2 site3 site4 -c 10.0 -metric -o network.ppm
- 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 network.ppm. The line-of-sight cover-
- age area of the transmitters are plotted as follows in the
- colors indicated (along with their corresponding RGB val-
- ues in decimal):
+ 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 network.ppm. 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):
site1: Green (0,255,0)
site2: Cyan (0,255,255)
site1 + site2 + site3 + site4: Gold2 (238,201,0)
- If separate .qth 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 SPLAT!.
-
-LONGLEY-RICE PATH LOSS ANALYSIS
- If the -c switch is replaced by a -L switch, a Longley-
- Rice path loss map for a transmitter site may be gener-
- ated:
-
- splat -t wnjt -L 30.0 -s cities.dat -b co34_d00.dat -o
- path_loss_map
-
- In this mode, SPLAT! generates a multi-color map illus-
- trating expected signal levels in areas surrounding the
- transmitter site. A legend at the bottom of the map cor-
- relates 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 -R switch. The argument must be
- given in miles (or kilometers if the -metric switch is
- used). If a range wider than the generated topographic
- map is specified, SPLAT! will perform Longley-Rice path
- loss calculations between all four corners of the area
- prediction map.
-
- The -db 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, SPLAT!'s path
- loss plot can be constrained to the region bounded by the
- 140 dB attenuation contour as follows:
-
- splat -t wnjt-dt -L 30.0 -s cities.dat -b co34_d00.dat -db
- 140 -o plot.ppm
-
-
-SIGNAL CONTOUR COLOR DEFINITION PARAMETERS
- The colors used to illustrate signal strength and path
- loss contours in SPLAT! generated coverage maps may be
- tailored by the user by creating or modifying SPLAT!'s
- color definition files. SPLAT! color definition files
- have the same base name as the transmitter's .qth file,
- but carry .lcf and .scf extensions.
-
- When a regional Longley-Rice analysis is performed and the
- transmitter's ERP is not specified or is zero, a .lcf path
- loss color definition file corresponding to the transmit-
- ter site (.qth) is read by SPLAT! from the current working
- directory. If a .lcf file corresponding to the transmit-
- ter site is not found, then a default file suitable for
- manual editing by the user is automatically generated by
- SPLAT!. If the transmitter's ERP is specified, then a
- signal strength map is generated and a signal strength
- color definition file (.scf) is read, or generated if one
- is not available in the current working directory.
-
- A path-loss color definition file possesses the following
- structure (wnjt-dt.lcf):
-
- ; SPLAT! Auto-generated Path-Loss Color Definition
- ("wnjt-dt.lcf") File
+ If separate .qth 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 loca-
+ tions on a single tower may be generated by SPLAT!.
+
+PATH LOSS ANALYSIS
+ If the -c switch is replaced by a -L switch, a Longley-Rice path loss
+ map for a transmitter site may be generated:
+
+ splat -t wnjt -L 30.0 -s cities.dat -b co34_d00.dat -o path_loss_map
+
+ In this mode, SPLAT! 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.
+
+ The -db switch allows a threshold to be set beyond which contours will
+ not be plotted on the map. For example, if a path loss beyond -140 dB
+ is irrelevant to the survey being conducted, SPLAT!'s path loss plot
+ can be constrained to the region bounded by the 140 dB attenuation con-
+ tour as follows:
+
+ splat -t wnjt-dt -L 30.0 -s cities.dat -b co34_d00.dat -db 140 -o
+ plot.ppm
+
+ The path loss contour threshold may be expressed as either a positive
+ or negative quantity.
+
+ The path loss analysis range may be modified to a user-specific dis-
+ tance using the -R switch. The argument must be given in miles (or
+ kilometers if the -metric switch is used). If a range wider than the
+ generated topographic map is specified, SPLAT! will perform Longley-
+ Rice path loss calculations between all four corners of the area pre-
+ diction map.
+
+ The colors used to illustrate contour regions in SPLAT! generated cov-
+ erage maps may be tailored by the user by creating or modifying
+ SPLAT!'s color definition files. SPLAT! color definition files have
+ the same base name as the transmitter's .qth file, but carry .lcf,
+ .scf, and .dcf extensions. If the necessary file does not exist in the
+ current working when SPLAT! is run, a file containing default color
+ definition parameters that is suitable for manual editing by the user
+ is written into the current directory.
+
+ When a regional Longley-Rice analysis is performed and the transmit-
+ ter's ERP is not specified or is zero, a .lcf path loss color defini-
+ tion file corresponding to the transmitter site (.qth) is read by
+ SPLAT! from the current working directory. If a .lcf file correspond-
+ ing to the transmitter site is not found, then a default file suitable
+ for manual editing by the user is automatically generated by SPLAT!.
+
+ A path loss color definition file possesses the following structure
+ (wnjt-dt.lcf):
+
+ ; SPLAT! Auto-generated Path-Loss Color Definition ("wnjt-dt.lcf")
+ File
;
- ; Format for the parameters held in this file is as fol-
- lows:
+ ; 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 speci-
- fied.
+ ; "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
+ ; for future runs of SPLAT! A total of 32 contour regions
; may be defined in this file.
;
;
220: 255, 0, 255
230: 255, 194, 204
+ 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 con-
+ tour.
+
+FIELD STRENGTH ANALYSIS
+ If the transmitter's effective radiated power (ERP) is specified in the
+ transmitter's .lrp file, or expressed on the command-line using the
+ -erp switch, field strength contours referenced to decibels over one
+ microvolt per meter (dBuV/m) rather than path loss are produced:
+
+ splat -t wnjt-dt -L 30.0 -erp 46000 -db 30 -o plot.ppm
- 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.
+ The -db switch can be used in this mode as before to limit the extent
+ to which field strength contours are plotted. When plotting field
+ strength contours, however, the argument given is interpreted as being
+ expressed in dBuV/m.
- SPLAT! signal strength color definition files share a very
- similar structure (wnjt-dt.scf):
+ SPLAT! field strength color definition files share a very similar
+ structure to .lcf files used for plotting path loss:
- ; SPLAT! Auto-generated Signal Color Definition ("wnjt-
- dt.scf") File
+ ; SPLAT! Auto-generated Signal Color Definition ("wnjt-dt.scf") File
;
- ; Format for the parameters held in this file is as fol-
- lows:
+ ; 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 speci-
- fied.
+ ; ...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
+ ; for future runs of SPLAT! A total of 32 contour regions
; may be defined in this file.
;
;
18: 142, 63, 255
8: 140, 0, 128
+ If the signal strength is greater than or equal to 128 dB over 1 micro-
+ volt 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 dis-
+ played, 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 ser-
+ vices in the United States are as follows:
+
- 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:
Analog Television Broadcasting
------------------------------
Digital Service Contour: 65 dBuV/m
+RECEIVED POWER LEVEL ANALYSIS
+ If the transmitter's effective radiated power (ERP) is specified in the
+ transmitter's .lrp file, or expressed on the command-line using the
+ -erp switch, and the -dbm switch is invoked, received power level con-
+ tours referenced to decibels over one milliwatt (dBm) are produced:
+
+ splat -t wnjt-dt -L 30.0 -erp 46000 -dbm -db -100 -o plot.ppm
+
+ The -db switch can be used to limit the extent to which received power
+ level contours are plotted. When plotting power level contours, the
+ argument given is interpreted as being expressed in dBm.
+
+ SPLAT! received power level color definition files share a very similar
+ structure to the color definition files described earlier, except that
+ the power levels in dBm may be either positive or negative, and are
+ limited to a range between +40 dBm and -200 dBm:
+
+ ; SPLAT! Auto-generated DBM Signal Level Color Definition ("wnjt-
+ dt.dcf") File
+ ;
+ ; Format for the parameters held in this file is as follows:
+ ;
+ ; dBm: red, green, blue
+ ;
+ ; ...where "dBm" is the received signal power level between +40 dBm
+ ; and -200 dBm, and "red", "green", and "blue" are the corresponding
+ ; RGB color definitions ranging from 0 to 255 for the region speci-
+ fied.
+ ;
+ ; 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.
+ ;
+ ;
+ +0: 255, 0, 0
+ -10: 255, 128, 0
+ -20: 255, 165, 0
+ -30: 255, 206, 0
+ -40: 255, 255, 0
+ -50: 184, 255, 0
+ -60: 0, 255, 0
+ -70: 0, 208, 0
+ -80: 0, 196, 196
+ -90: 0, 148, 255
+ -100: 80, 80, 255
+ -110: 0, 38, 255
+ -120: 142, 63, 255
+ -130: 196, 54, 255
+ -140: 255, 0, 255
+ -150: 255, 194, 204
+
ANTENNA RADIATION PATTERN PARAMETERS
- Normalized field voltage patterns for a transmitting
- antenna's horizontal and vertical planes are imported
- automatically into SPLAT! 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 transmit-
- ter and LRP files, but with .az and .el extensions for
- azimuth and elevation pattern files, respectively. Speci-
- fications regarding pattern rotation (if any) and mechani-
- cal beam tilt and tilt direction (if any) are also con-
- tained within SPLAT! antenna pattern files.
-
- For example, the first few lines of a SPLAT! azimuth pat-
- tern file might appear as follows (kvea.az):
+ Normalized field voltage patterns for a transmitting antenna's horizon-
+ tal and vertical planes are imported automatically into SPLAT! when a
+ path loss, field strength, or received power level 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 .az and
+ .el 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 SPLAT!
+ antenna pattern files.
+
+ For example, the first few lines of a SPLAT! azimuth pattern file might
+ appear as follows (kvea.az):
183.0
0 0.8950590
7 0.9047923
8 0.9060051
- The first line of the .az file specifies the amount of
- azimuthal pattern rotation (measured clockwise in degrees
- from True North) to be applied by SPLAT! to the data con-
- tained in the .az file. This is followed by azimuth head-
- ings (0 to 360 degrees) and their associated normalized
- field patterns (0.000 to 1.000) separated by whitespace.
-
- The structure of SPLAT! elevation pattern files is
- slightly different. The first line of the .el file speci-
- fies the amount of mechanical beam tilt applied to the
- antenna. Note that a downward tilt (below the horizon) is
- expressed as a positive angle, while an upward tilt (above
- the horizon) is expressed as a negative angle. This data
- is followed by the azimuthal direction of the tilt, sepa-
- rated 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. Eleva-
- tion angles must be specified over a -10.0 to +90.0 degree
- range. As was the convention with mechanical beamtilt,
- negative elevation angles are used to represent elevations
- above the horizon, while positive angles represents eleva-
- tions below the horizon.
-
- For example, the first few lines a SPLAT! elevation pat-
- tern file might appear as follows (kvea.el):
+ The first line of the .az file specifies the amount of azimuthal pat-
+ tern rotation (measured clockwise in degrees from True North) to be
+ applied by SPLAT! to the data contained in the .az file. This is fol-
+ lowed by azimuth headings (0 to 360 degrees) and their associated nor-
+ malized field patterns (0.000 to 1.000) separated by whitespace.
+
+ The structure of SPLAT! elevation pattern files is slightly different.
+ The first line of the .el file specifies the amount of mechanical beam
+ tilt applied to the antenna. Note that a downward tilt (below the
+ horizon) is expressed as a positive angle, while an upward tilt (above
+ the horizon) is expressed as a negative angle. 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 corre-
+ sponding 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, negative elevation angles are used to represent elevations
+ above the horizon, while positive angles represents elevations below
+ the horizon.
+
+ For example, the first few lines a SPLAT! elevation pattern file might
+ appear as follows (kvea.el):
1.1 130.0
-10.0 0.172
-6.5 0.109
-6.0 0.185
- In this example, the antenna is mechanically tilted down-
- ward 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, SPLAT! will
- interpolate the values provided to determine the data at
- the required resolution, although this may result in a
- loss in accuracy.
-
-
-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 cov-
- erage 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 SPLAT! to rapidly produce a
- revised path loss map.
-
- For example, a path loss output file can be generated by
- SPLAT! for a receive site 30 feet above ground level over
- a 50 mile radius surrounding a transmitter site to a maxi-
- mum path loss of 140 dB using the following syntax:
-
- splat -t kvea -L 30.0 -R 50.0 -db 140 -plo pathloss.dat
-
- SPLAT! path loss output files often exceed 100 megabytes
- in size. They contain information relating to the bound-
- aries of region they describe followed by latitudes
- (degrees North), longitudes (degrees West), azimuths, ele-
- vations (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 SPLAT! path loss output file take on the fol-
- lowing appearance (pathloss.dat):
+ 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, SPLAT!
+ will interpolate the values provided to determine the data at the
+ required resolution, although this may result in a loss in accuracy.
+
+EXPORTING AND IMPORTING REGIONAL CONTOUR DATA
+ Performing a regional coverage analysis based on a Longley-Rice path
+ analysis can be a very time consuming process, especially if the analy-
+ sis is performed repeatedly to discover what effects changes to a
+ transmitter's antenna radiation pattern make to the predicted coverage
+ area.
+
+ This process can be expedited by exporting the contour data produced by
+ SPLAT! to an alphanumeric output (.ano) file. The data contained in
+ this file can then be modified to incorporate antenna pattern effects,
+ and imported back into SPLAT! to quickly produce a revised contour map.
+ Depending on the way in which SPLAT! is invoked, alphanumeric output
+ files can describe regional path loss, signal strength, or received
+ signal power levels.
+
+ For example, an alphanumeric output file containing path loss informa-
+ tion can be generated by SPLAT! 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 (assuming ERP is not specified in the transmitter's
+ .lrp file) using the following syntax:
+
+ splat -t kvea -L 30.0 -R 50.0 -db 140 -ano pathloss.dat
+
+ If ERP is specified in the .lrp file or on the command line through the
+ -erp switch, the alphanumeric output file will instead contain pre-
+ dicted field values in dBuV/m. If the -dBm command line switch is
+ used, then the alphanumeric output file will contain receive signal
+ power levels in dBm.
+
+ SPLAT! alphanumeric output files can exceed many hundreds of megabytes
+ in size. They contain information relating to the boundaries of the
+ region they describe followed by latitudes (degrees North), longitudes
+ (degrees West), azimuths (referenced to True North), elevations (to the
+ first obstruction), followed by either path loss (in dB), received
+ field strength (in dBuV/m), or received signal power level (in dBm)
+ without regard to the transmitting antenna's radiation pattern.
+
+ The first few lines of a SPLAT! alphanumeric output file could take on
+ the following appearance (pathloss.dat):
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
-
- It is not uncommon for SPLAT! 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 vim text editor has proven capable of
- editing files of this size.
-
- Note as was the case in the antenna pattern files, nega-
- tive 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 -L switch if the path between trans-
- mitter and receiver is unobstructed. If the path between
- the transmitter and receiver is obstructed, then the ele-
- vation angle to the first obstruction is returned by
- SPLAT!. 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 SPLAT! path loss files to reflect antenna
- pattern data, only the last column (path loss) 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 SPLAT!
- for generating revised coverage maps:
-
- splat -t kvea -pli pathloss.dat -s city.dat -b county.dat
- -o map.ppm
-
- SPLAT! path loss files can also be used for conducting
- coverage or interference studies outside of SPLAT!.
+ 35, 34 ; max_north, min_north
+ 34.2265424, 118.0631096, 48.199, -32.747, 67.70
+ 34.2270358, 118.0624421, 48.199, -19.161, 73.72
+ 34.2275292, 118.0617747, 48.199, -13.714, 77.24
+ 34.2280226, 118.0611072, 48.199, -10.508, 79.74
+ 34.2290094, 118.0597723, 48.199, -11.806, 83.26 *
+ 34.2295028, 118.0591048, 48.199, -11.806, 135.47 *
+ 34.2299962, 118.0584373, 48.199, -15.358, 137.06 *
+ 34.2304896, 118.0577698, 48.199, -15.358, 149.87 *
+ 34.2314763, 118.0564348, 48.199, -15.358, 154.16 *
+ 34.2319697, 118.0557673, 48.199, -11.806, 153.42 *
+ 34.2324631, 118.0550997, 48.199, -11.806, 137.63 *
+ 34.2329564, 118.0544322, 48.199, -11.806, 139.23 *
+ 34.2339432, 118.0530971, 48.199, -11.806, 139.75 *
+ 34.2344365, 118.0524295, 48.199, -11.806, 151.01 *
+ 34.2349299, 118.0517620, 48.199, -11.806, 147.71 *
+ 34.2354232, 118.0510944, 48.199, -15.358, 159.49 *
+ 34.2364099, 118.0497592, 48.199, -15.358, 151.67 *
+
+ Comments can be placed in the file if they are proceeded by a semicolon
+ character. The vim 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 -L switch if the path between transmitter and
+ receiver is unobstructed. If the path between the transmitter and
+ receiver is obstructed, an asterisk (*) is placed on the end of the
+ line, and the elevation angle returned by SPLAT! refers the elevation
+ angle to the first obstruction rather than the geographic location
+ specified on the line. This is done in response to the fact that the
+ Longley-Rice model considers the energy reaching a distant point over
+ an obstructed path to be the result of the energy scattered over the
+ top of the first obstruction along the path. Since energy cannot reach
+ the obstructed location directly, the actual elevation angle to the
+ destination over such a path becomes irrelevant.
+
+ When modifying SPLAT! path loss files to reflect antenna pattern data,
+ only the last numeric column should be amended to reflect the antenna's
+ normalized gain at the azimuth and elevation angles specified in the
+ file. Programs and scripts capable of performing this task are left as
+ an exercise for the user.
+
+ Modified alphanumeric output files can be imported back into SPLAT!
+ for generating revised coverage maps provided that the ERP and -dBm
+ options are used as they were when the alphanumeric output file was
+ originally generated:
+
+ splat -t kvea -ani pathloss.dat -s city.dat -b county.dat -o map.ppm
+
+ Note that alphanumeric output files generated by splat cannot be used
+ with splat-hd, or vice-versa due to the resolution incompatibility
+ between the two versions of the program. Also, each of the three types
+ of alphanumeric output files are incompatible with one another, so a
+ file containing path loss data cannot be imported into SPLAT! to pro-
+ duce signal strength or received power level contours, etc.
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 SPLAT! analysis being conducted, but
- noticeably absent from the SDF files being used. A user-
- defined terrain file is imported into a SPLAT! analysis
- using the -udt switch:
+ A user-defined terrain file is a user-generated text file containing
+ latitudes, longitudes, and heights above ground level of specific ter-
+ rain features believed to be of importance to the SPLAT! analysis being
+ conducted, but noticeably absent from the SDF files being used. A
+ user-defined terrain file is imported into a SPLAT! analysis using the
+ -udt switch:
splat -t tx_site -r rx_site -udt udt_file.txt -o map.ppm
- A user-defined terrain file has the following appearance
- and structure:
+ A user-defined terrain file has the following appearance and structure:
40.32180556, 74.1325, 100.0 meters
40.321805, 74.1315, 300.0
40.3218055, 74.1305, 100.0 meters
- Terrain height is interpreted as being described in feet
- above ground level unless followed by the word meters, and
- is added on top of 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. Fea-
- tures described in the user-defined terrain file that
- overlap previously defined features in the file are
- ignored by SPLAT!.
+ Terrain height is interpreted as being described in feet above ground
+ level unless followed by the word meters, and is added on top of the
+ terrain specified in the SDF data for the locations specified. Be
+ aware that each user-defined terrain feature specified will be inter-
+ preted as being 3-arc seconds in both latitude and longitude in splat
+ and 1 arc-second in latitude and longitude in splat-hd. Features
+ described in the user-defined terrain file that overlap previously
+ defined features in the file are ignored by SPLAT! to avoid ambiguity.
+
+GROUND CLUTTER
+ The height of ground clutter can be specified using the -gc switch:
+
+ splat -t wnjt-dt -r kd2bd -gc 30.0 -H wnjt-dt_path.png
+
+ The -gc switch as the effect of raising the overall terrain by the
+ specified amount in feet (or meters if the -metric switch is invoked),
+ except over areas at sea-level and at the transmitting and receiving
+ antenna locations. Note that the addition of ground clutter does not
+ necessarily modify the Longley-Rice path loss results unless the addi-
+ tional clutter height results in a switch in the propagation mode from
+ a less obstructed path to a more obstructed path (from Line Of Sight to
+ Single Horizon Diffraction Dominant, for example). It does, however,
+ affect Fresnel zone clearances and line of sight determinations.
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 -n switch should be invoked as fol-
- lows:
+ 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 -n switch
+ should be invoked as follows:
splat -t tx_site -r rx_site -n -o topo_map.ppm
splat -t tx_site -r rx_site -N -o topo_map.ppm
- 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:
+ 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:
- splat -t tx_site -R 50.0 -s NJ_Cities -b NJ_Counties -o
- topo_map.ppm
+ splat -t tx_site -R 50.0 -s NJ_Cities -b NJ_Counties -o topo_map.ppm
- where -R specifies the minimum radius of the map in miles
- (or kilometers if the -metric switch is used). Note that
- the tx_site name and location are not displayed in this
- example. If display of this information is desired, sim-
- ply create a SPLAT! city file (-s option) and append it to
- the list of command-line options illustrated above.
+ where -R specifies the minimum radius of the map in miles (or kilome-
+ ters if the -metric switch is used). Note that the tx_site name and
+ location are not displayed in this example. If display of this infor-
+ mation is desired, simply create a SPLAT! city file (-s option) and
+ append it to the list of command-line options illustrated above.
- If the -o switch and output filename are omitted in these
- operations, topographic output is written to a file named
- tx_site.ppm in the current working directory by default.
+ If the -o switch and output filename are omitted in these operations,
+ topographic output is written to a file named tx_site.ppm in the cur-
+ rent working directory by default.
GEOREFERENCE FILE GENERATION
- Topographic, coverage (-c), and path loss contour (-L)
- maps generated by SPLAT! may be imported into Xastir (X
- Amateur Station Tracking and Information Reporting) soft-
- ware by generating a georeference file using SPLAT!'s -geo
- switch:
+ Topographic, coverage (-c), and path loss contour (-L) maps generated
+ by SPLAT! may be imported into Xastir (X Amateur Station Tracking and
+ Information Reporting) software by generating a georeference file using
+ SPLAT!'s -geo switch:
- splat -t kd2bd -R 50.0 -s NJ_Cities -b NJ_Counties -geo -o
- map.ppm
+ splat -t kd2bd -R 50.0 -s NJ_Cities -b NJ_Counties -geo -o map.ppm
- The georeference file generated will have the same base
- name as the -o file specified, but have a .geo extension,
- and permit proper interpretation and display of SPLAT!'s
- .ppm graphics in Xastir software.
+ The georeference file generated will have the same base name as the -o
+ file specified, but have a .geo extension, and permit proper interpre-
+ tation and display of SPLAT!'s .ppm graphics in Xastir software.
GOOGLE MAP KML FILE GENERATION
- Keyhole Markup Language files compatible with Google Earth
- may be generated by SPLAT! when performing point-to-point
- or regional coverage analyses by invoking the -kml switch:
+ Keyhole Markup Language files compatible with Google Earth may be gen-
+ erated by SPLAT! when performing point-to-point or regional coverage
+ analyses by invoking the -kml switch:
splat -t wnjt-dt -r kd2bd -kml
- The KML file generated will have the same filename struc-
- ture as a Path Analysis Report for the transmitter and
- receiver site names given, except it will carry a .kml
- extension.
-
- Once loaded into Google Earth (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 dis-
- played in green. Google Earth's navigation tools allow
- the user to "fly" around the path, identify landmarks,
- roads, and other featured content.
-
- When performing regional coverage analysis, the .kml file
- generated by SPLAT! will permit path loss or signal
- strength contours to be layered on top of Google Earth's
- display in a semi-transparent manner. The generated .kml
- file will have the same basename as that of the .ppm file
- normally generated.
+ 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 .kml extension.
+
+ Once loaded into Google Earth (File --> Open), the KML file will anno-
+ tate 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.
+ Google Earth's navigation tools allow the user to "fly" around the
+ path, identify landmarks, roads, and other featured content.
+
+ When performing regional coverage analysis, the .kml file generated by
+ SPLAT! will permit path loss or signal strength contours to be layered
+ on top of Google Earth's display in a semi-transparent manner. The
+ generated .kml file will have the same basename as that of the .ppm
+ file normally generated.
DETERMINATION OF ANTENNA HEIGHT ABOVE AVERAGE TERRAIN
- SPLAT! determines antenna height above average terrain
- (HAAT) according to the procedure defined by Federal Com-
- munications 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 avail-
- able), 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 com-
- pliance with FCC Part 73.313(d) in areas along the borders
- of the United States if the SDF files used by SPLAT! are
- SRTM-derived.
-
- When performing point-to-point terrain analysis, SPLAT!
- 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
+ SPLAT! 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-3 elevation data, unlike older 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 SPLAT! are SRTM-derived.
+
+ When performing point-to-point terrain analysis, SPLAT! 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 ques-
+ tion does not lie within 10 miles of the boundary of the topography
data in memory.
- When performing area prediction analysis, enough topogra-
- phy data is normally loaded by SPLAT! to perform average
- terrain calculations. Under such conditions, SPLAT! 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, SPLAT!
- reports No Terrain for the radial paths affected.
-
-RESTRICTING THE MAXIMUM SIZE OF AN ANALYSIS REGION
- SPLAT! 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 #define MAXPAGES statement in the
- first several lines of splat.cpp sets the maximum number
- of "pages" available for holding topography data. It also
- sets the maximum size of the topographic maps generated by
- SPLAT!. MAXPAGES is set to 9 by default. If SPLAT! pro-
- duces 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 SPLAT! with the
- number of MAXPAGES specified. In situations where avail-
- able memory is low, MAXPAGES may be reduced to 4 with the
- understanding that this will greatly limit the maximum
- region SPLAT! will be able to analyze. If 118 megabytes
- or more of total memory (swap space plus RAM) is avail-
- able, 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 dis-
- tances of over 1000 miles.
+ When performing area prediction analysis, enough topography data is
+ normally loaded by SPLAT! to perform average terrain calculations.
+ Under such conditions, SPLAT! 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, SPLAT! reports No Terrain for the radial paths
+ affected.
ADDITIONAL INFORMATION
- The latest news and information regarding SPLAT! software
- is available through the official SPLAT! software web page
- located at: http://www.qsl.net/kd2bd/splat.html.
+ The latest news and information regarding SPLAT! software is available
+ through the official SPLAT! software web page located at:
+ http://www.qsl.net/kd2bd/splat.html.
AUTHORS
John A. Magliacane, KD2BD <kd2bd@amsat.org>
Doug McDonald <mcdonald@scs.uiuc.edu>
Original Longley-Rice Model integration
- Ron Bentley <ronbentley@earthlink.net>
+ Ron Bentley <ronbentley@embarqmail.com>
Fresnel Zone plotting and clearance determination
-KD2BD Software 16 September 2007 SPLAT!(1)
+KD2BD Software 15 November 2008 SPLAT!(1)
projects / debian / splat / blobdiff