Geocoding the DTEMS digital terrain matrix and radar image products

The Digital Terrain Elevation Mapping System (DTEMS) is a system that will combine SAR interferometry with high altitude flight operations in a NASA ER-2 for large area high precision digital terrain matrix (DTM) and polarimetric synthetic aperture radar (SAR) imagery collection. DTEMS will provide a national geocoded DTM with less than one meter error in geo-centered rectangular coordinates and three meter post spacing. Geocoding will obtain the DTM in geo-centered rectangular coordinates referenced to the WGS-84 mean ellipsoid. Coordinate transformations will convert the DTM to geographic or to universal transverse mercator (UTM) coordinates. Earth tide models will provide temporal corrections for diurnal deviations from the mean ellipsoid. The US Air Force Wide Area Differential GPS network (which is called WAGT) will be used to make differential corrections on the GPS data collected during each flight. In post flight processing the data will be transmitted via Internet to the differential correction processor. The corrected data will be transmitted via Internet back to the DTEMS data processing facility.