Automated DEM Production Using ESA Tandem Mission Data for the Caribou-Poker Creek LTER Watershed, Alaska

The Alaska SAR Facility has developed an automated procedure for production of a digital elevation model (DEM) from ESA tandem mission data. This software processes from ASF Computer Compatible Signal Data (CCSD) or Level Zero (raw) products to a map-projected, ground-range 30m DEM. Several advanced techniques have been integrated into the procedures to improve accuracy and to allow full automation. This spring, a test site at the Caribou-Poker Long Term Ecological Research (LTER) watershed was analyzed in collaboration with Larry Hinzman (Principal Investigator) and the Arctic Region Supercomputing Center. An accuracy assessment of the results for four ESA tandem pairs showed average differences ranging from approximately 4 to 8 meters in elevation when compared with field measurements using differential GPS. The final mosaic had an average difference of 4.68 meters in elevation. Point target analysis of existing 3x6 and 2x3 arc-second USGS digital elevation data showed an average difference of 19.97 and 10.04 meters in elevation, respectively. These advances in accuracy are due to use of precision timing and orbital data in an interferometric SAR processor using an average Doppler, precise baseline refinement, and direct ground rectification. The Alaska SAR Facility continues to refine its interferometric SAR processor in support of NASA-approved users.