-compatible with this utility are available at no cost via the Internet at:
-\fIhttp://edcsgs9.cr.usgs.gov/glis/hyper/guide/1_dgr_demfig/index1m.html\fP.
-
-SPLAT Data Files contain topographic elevations to the nearest meter
-above mean sea level for 1-degree by 1-degree regions of the earth with
-a resolution of 3-arc seconds. SDF files can be read in either standard
-format (\fI.sdf\fP) as generated by the \fBusgs2sdf\fP utility, or in
-bzip2 compressed format (\fI.sdf.bz2\fP). Since uncompressed files can
-be slightly faster to load than compressed files, \fBSPLAT!\fP searches
-for the needed SDF data in uncompressed format first. If such data cannot
-located, then \fBSPLAT!\fP tries to read the data in bzip2 compressed
+compatible with this utility may be downloaded from:
+\fIhttp://edcftp.cr.usgs.gov/pub/data/DEM/250/\fP.
+
+Significantly better resolution can be obtained through the use
+of SRTM-3 Version 2 digital elevation models. These models are the
+result of the STS-99 Space Shuttle Radar Topography Mission, and are
+available for most populated regions of the Earth. SPLAT Data Files
+may be generated from SRTM data using the included \fBsrtm2sdf\fP utility.
+SRTM-3 Version 2 data may be obtained through anonymous FTP from:
+\fIftp://e0srp01u.ecs.nasa.gov:21/srtm/version2/\fP
+
+Despite the higher accuracy that SRTM data has to offer, some voids
+in the data sets exist. When voids are detected, the \fBsrtm2sdf\fP
+utility replaces them with corresponding data found in existing SDF
+files (that were presumably created from earlier USGS data through the
+\fBusgs2sdf\fP utility). If USGS-derived SDF data is not available, voids
+are handled through adjacent pixel averaging, or direct replacement.
+
+SPLAT Data Files contain integer value topographic elevations (in meters)
+referenced to mean sea level for 1-degree by 1-degree regions of the
+earth with a resolution of 3-arc seconds. SDF files can be read in
+either standard format (\fI.sdf\fP) as generated by the \fBusgs2sdf\fP
+and \fBsrtm2sdf\fP utilities, or in bzip2 compressed format
+(\fI.sdf.bz2\fP). Since uncompressed files can be processed slightly
+faster than files that have been compressed, \fBSPLAT!\fP searches for
+the needed SDF data in uncompressed format first. If uncompressed data
+cannot located, \fBSPLAT!\fP then searches for data in bzip2 compressed