An Improved Topography-Dependent Motion Compensation Approach for Airborne Repeat-Pass Interferometric SAR Systems
Tang Xiao-qing①②; Xiang Mao-sheng①; Wu Yi-rong①
①Institute of Electronics, Chinese Academy of Sciences, National Key Laboratory of Microwave Imaging Technology, Beijing 100190, China;②Graduate University of Chinese Academy of Sciences, Beijing 100049, China
Abstract:In this paper, the precise topography-dependent motion compensation for repeat-pass InSAR is studied. The effects of the residual motion errors caused by the flat surface assumption and center-beam approximation are analyzed, which shows the necessity of performing a precise topography-dependent motion compensation for the repeat-pass InSAR systems. The precision requirement for the external DEM data is analyzed to show the feasibility of deriving precise DEM data by motion compensation based on rough DEM data. An improved approach is presented according to the deficiencies of the existing topography-dependent motion compensation approaches. It can adjust the parameters according to the conditions of trajectory deviations and topography variations, so it has the advantage of performing the precise motion compensation efficiently. Finally, the processing results of the X-band airborne repeat-pass interferometric SAR data confirm its validity and superiority in precision and efficiency compared to the original algorithms.