Space-surface Bistatic SAR Tomography: A Promising Approach for Accurate Local 3D Reconstruction

With a flexibly deployed receiver, space-surface bistatic Synthetic Aperture Radar (SS-BiSAR) can increase the observation sensitivity in the north-south direction, which is a promising method for local high-precision three-dimensional deformation retrieval. However, in urban areas, the layover effect hinders the determination of the dominant scatterer in each resolution cell. Multi-baseline SAR tomography is an effective approach to solving overlaid scatterers. This paper presents the first experiment result of SS-BiSAR tomography. By estimating and removing the interferometric fringes, the repeat-track orbit errors are effectively corrected. The experiment was conducted based on the first L-band spaceborne twin SAR - the Chinese Lutan-1 (LT-1). A total of 11 repeat-track SAR images were acquired, and three-dimensional point clouds of a building area was recovered, with an accuracy of approximately 4 meters.