Removal of residual errors from SAR-derived digital elevation models for improved topographic mapping of low-relief areas

Interferometric synthetic aperture radar data can be used to precisely map topography, but low-relief areas are problematic because errors in the data can be large compared to the topographic variations. The NASA/JPL TOPSAR system acquired data over a low-relief test site on the Texas coast in 1996. Due to unusually high turbulence during the acquisition and the mild topography, residual height errors were visible in the digital elevation model (DEM). Characteristics of the error signal are described and a method is outlined for removing the residual error and mosaicking the affected TOPSAR frames