A Novel Absolute Interferometric Phase Determination Algorithm for InSAR Processing

For the purpose of global mapping, absolute interferometric phase (AIP) determination without ground control points is one of the keytechniques in spaceborne interferometric synthetic aperture radar (InSAR) processing. In this paper, a novel AIP determination method is proposed based on the fusion of datum acquired by the ascending and descending orbits. Firstly, the influence of AIP error on the InSAR positioning is analyzed. The horizontal shift directions introduced by the AIP bias for ascending- and descending orbit data are different. Then, the AIP can be determined by minimization of the height difference between ascending- and descending-orbit data. The effectiveness of the proposed method is validated by the experiment with TanDEM-X SAR data.