HIGH RESOLUTION STEREO SATELLITE ELEVATION MAPPING ACCURACY ASSESSMENT

The availability of over 45,000 accurately surveyed ground points covering an area of 1,000 km 2 in central Eritrea has enabled comprehensive accuracy assessments of elevation mapping from IKONOS, GeoEye-1, WorldView-1 and WorldView-2 stereo satellite photos. The ground survey points were acquired for a base metal mining exploration gravity survey. All of the ground points were surveyed with Real Time Kinematic GPS instruments and are accurate to 2 cm. The IKONOS, GeoEye-1 and WorldView-1 stereo photos were each registered to a single ground control point, and the WorldView-2 stereo photos were registered to two ground control points. Each of the stereo pairs covers a slightly different ground area. Using elevation checkpoints in areas with slopes of less than 20% grade, the elevation mapping accuracies were determined as follows: IKONOS acquired August 2006, 200 km 2 , RMSE 48cm using 10,081 points; GeoEye-1 acquired February 2009, 240 km 2 , RMSE 44cm using 10,824 points; GeoEye-1 acquired September 2009, 225 km 2 , RMSE 31cm using 8,983 points; WorldView-1 acquired October 2008, 374 km 2 , RMSE 44cm using 15,020 points; WorldView-2 acquired January 2010, 400 km 2 , RMSE 28cm using 16,687 points. The stereo satellite elevation mapping was carried out with PhotoSat’s Geophysical Stereo Satellite Elevation Mapping System. The survey points were used in the development and verification of the system. The PhotoSat Geophysical Stereo Satellite Elevation Mapping System is the subject of another paper submitted for the ASPRS conference.