Spaceborne Bistatic Stereo-Radargrammetry

This paper describes the evolution of classic stereo-radargrammetric techniques to the bistatic spaceborne geometry. When a monostatic image and a bistatic one are adopted to form the stereoscopic pair, new relations are needed to define parallax as a function of the peculiar parameters of bistatic surveying geometry. Two models are analyzed to extract parallax difference from radar data: parallax difference estimation from SAR images and parallax difference calculation by exploiting slant-range equations. An error budget of elevation measurement accuracy has been performed, showing that bistatic radargrammetric techniques applied to a spaceborne scenario mission can achieve an error in height measurement adequate for several applications and lower than the one obtained by previous monostatic experiments.