================
Utilities for use with SPLAT! software are found under the
-splat-1.1.1/utils directory. They include the following:
+splat-1.3.0/utils directory. They include the following:
srtm2sdf
========
-The srtm2sdf utility generates SPLAT Data Files (SDFs) from 3-arc second
-STS-99 Space Shuttle Topography Mission (SRTM-3) elevation data files.
-This data is of a much higher quality than that contained in older USGS
-Digital Elevation Models of the same resolution. However, many SRTM-3
-Version 2 elevation models contain data "voids" and "wells" that are the
-consequence of the radar mapping process.
+The srtm2sdf utility generates SPLAT Data Files (SDFs) from STS-99
+Space Shuttle Topography Mission (SRTM) elevation data files. This
+data is of a much higher quality than that contained in older USGS
+Digital Elevation Models of the same resolution. However, many SRTM
+Version 2 elevation models contain data "spikes", "voids", and "wells"
+that are the consequence of the radar mapping process.
The srtm2sdf utility has the ability to detect and replace SRTM data
-outliers with equivalent SDF data created through the usgs2sdf utility
-(below). If equivalent USGS-derived SPLAT Data Files are not available,
-SRTM outliers are handled either through adjacent pixel averaging, or by
-threshold limiting using user-specified limits. Of all three methods,
-the USGS-derived SDF replacement method yields the best results.
+outliers with equivalent usgs2sdf derived SDF data (see usgs2sdf below).
+If such data is not available, SRTM outliers are handled either through
+adjacent pixel averaging, or by threshold limiting using user-specified
+limits. Of all three methods, the USGS-derived SDF replacement method
+yields the best results.
-SRTM-3 Version 2 Elevation Data may be downloaded from:
+The srtm2sdf utility processes SRTM-3 3-arc second resolution data
+or use with SPLAT! operating in standard definition mode.
+
+SRTM-3 Version 2 Elevation Data files may be downloaded from:
ftp://e0srp01u.ecs.nasa.gov:21/srtm/version2/
The srtm2sdf utility accepts command-line options as follows:
--d: used to specify the directory path to the location of existing
- SDF files (presumably created at an earlier date through the
- usgs2sdf or postdownload utility) that are to be used to replace
- outliers found in the SRTM data file. The -d option overrides
- the default path specified in your $HOME/.splat_path file.
-
--n: used to specify the elevation (in meters) below which SRTM data
- is replaced. Below this limit, SRTM elevation data is either
- replaced using existing SDF equivalent files, or averaged among
- adjacent elevation data points. The default threshold for the
- replacement limit is sea-level (0 meters). Unless elevations
- below sea-level are known to exist for the region being
- processed by the srtm2sdf utility, the -n option need not be
- specified.
+-d: used to specify the directory path to the location of usgs2sdf
+ derived SDF files that are to be used to replace outliers found
+ in the SRTM data file. The -d option overrides the default path
+ specified in your $HOME/.splat_path file.
+
+-n: used to specify the elevation (in meters) below which SRTM data
+ is either replaced with usgs2sdf-derived SDF data, or averaged
+ among adjacent elevation data points. The default threshold for
+ the replacement limit is sea-level (0 meters). Unless elevations
+ below sea-level are known to exist for the region being
+ processed by the srtm2sdf utility, the -n option need not be
+ specified.
Some examples of srtm2sdf use:
In all cases, SDF files are written into the current working directory.
+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/website/seamless/
+
+Once the region of the world has been selected at this site, select the
+"Define Download Area By Coordinates" button under "Downloads". Proceed
+to request the download of the region(s) desired in 1 degree by 1 degree
+regions only, and make sure bounding coordinates entered fall exactly on
+whole numbers of latitude and longitude (no decimal fractions of a degree).
+
+Select the "Add Area" button at the bottom.
+
+On the next screen, select "Modify Data Request". On the subsequent screen,
+de-select the National Elevation Dataset (NED) format and select "SRTM 3 arc
+sec - Shuttle Radar Topography Mission [Finished]". Change the format from
+ArcGrid to BIL, and from HTML to TXT.
+
+Select the "Save Changes and Return To Summary" button.
+
+Select the "Download" button, and save the file once it has been sent to
+your web browser.
+
+Uncompressing the file will generate a directory containing all files
+contained within the downloaded archive. Move into the directory and
+invoke srtm2sdf as described above with the filename having the .bil
+extension given as its argument. Finally, move or copy the generated
+.sdf file to your SPLAT! working directory.
+
+
+srtm2sdf-hd
+===========
+The srtm2sdf-hd utility operates in an identical manner as srtm2sdf,
+but is used to generate HD SDF files from SRTM-1 one-arc second
+resolution data files for use with SPLAT! HD. SRTM-1 data files
+are available for the United States and its territories and
+possessions, and may be downloaded from:
+
+ ftp://e0srp01u.ecs.nasa.gov:21/srtm/version2/SRTM1/
+
usgs2sdf
========
takes as an argument the name of the gzipped Digital Elevation Model
(DEM) downloaded from the US Geological Survey (ie: wilmington-w.gz).
postdownload uncompresses the DEM file, adds necessary record delimiters,
-and invokes usgs2sdf to produce a SPLAT Data File (SDF).
+and invokes usgs2sdf to produce a SPLAT! Data File (SDF).
USGS Digital Elevation Models may be downloaded from:
citydecoder pl34 | sort > cities.nj.dat
-A list of FIPS codes (fips.txt) is included under splat/utils for your
-convenience.
+A list of FIPS codes (fips.txt) is included under splat-1.3.0/utils
+for your convenience.
fontdata
fontdata s.fnt.gz
+bearing
+=======
+The bearing utility reads a pair of .qth files specified on the command
+line, and returns the azimuth bearing and great circle path distance between
+the two points specified. A -metric switch is available so that distances
+can be provided in kilometers rather than statute miles. SPLAT! provides
+similar distance and bearing information between two specific site locations.
+The bearing utility, however, provides the information quickly and easily
+over great distances without having to run SPLAT!
+
+
Building The Utilities
======================
Normally, these utilities are built and installed along with SPLAT!
---
John A. Magliacane, KD2BD
-March 2006
+August 2008