The topographic maps published by GPSMaps were generated from publicly available databases and converted to the Garmin img-format which can be loaded to Garmin eTrex® GPS receivers. The maps provide essential information on the topography for mountaineers and hikers.
The GTOPO30 digital elevation model published by the United States Geological Survey provides the fundament for the topographic maps published by GPSMaps. GTOPO30 is a global 30-second grid digital elevation model.
For some mountain areas and areas to the north of 60°N lacking SRTM data, the excellent data provided by Jonathan de Ferranti are used.
Maps exhibiting enhanced resolution and improved accuracy based upon the SRTM digital elevation model are under preparation. At present, all GPSMaps can be combined with digital maps published by Garmin and other publishers.
Customised maps can be generated on request if data digital elevation are provided or available from other sources.