GPSdings elevations

elevations adds elevation data (<ele> elements) to GPX 1.1 files. The elevations are looked up in the publicly available Shuttle Radar Topography Mission data (version 2.1, SRTM1 where publicly available SRTM3 elsewhere). Data is fetched as NASA HGT files via HTTP or read from a local cache. You can make gpsdings elevations use custom elevation data by saving them as .hgt files in the cache directory.
If you are behind a proxy you must set the corresponding java system properties http.proxyHost and http.proxyPort when you invoke gpsdings (i. e. java -Dhttp.proxyHost=my.proxy.com -Dhttp.proxyPort=8080 -jar gpsdings.jar). gpsdings elevations will process standard input to standard output if no files are specified or if a dash (-) is used in place of the files argument.

USAGE: gpsdings elevations [options] [<file(s)>]
 -T,--Trkpt            Add elevations to track points (trkpt elements).
 -R,--Rtept            Add elevations to route points (rtept elements).
 -W,--Wpt              Add elevations to way points (wpt elements).
 -O,--Overwrite        Overwrite existing elevation information.
 -t,--todir <dir>      Save processed files to this directory. This argument is
                       required when you are processing files (as opposed to
                       standard input).
 -c,--cache-dir <dir>  Sets the directory where hgt files are stored locally.
                       The default is the temporary directory (as defined by the
                       system property java.io.tmpdir).
 -h,--help             Print this help and exit.
 -l,--license          Display the licenses for this program and included libraries.

GPX 1.1 can be created from a lot of other geo-coordinate formats with GPSBabel. Use the option "gpxver=1.1" in GPSBabelGUI or "-o gpx,gpxver=1.1" for command line gpsbabel.
This program is licensed to you under the GNU General Public License version 3.