GB-InSAR interferogram processing method to generate DEM based on PS technology

摘要

Ground-based interferometry synthetic aperture radar (GB-InSAR) technology is becoming an important terrain mapping technology as it has the characteristics of short observation intervals, flexible operation environment and high data precision. Compared with air/space borne InSAR system, it is much easier for GB-InSAR to acquire repeat-pass/short-baseline data set, which can bring huge convenience on permanent scatterer (PS) technology. By using PS technology, on the one hand, the error caused by low coherence can be avoided, and on the other hand, the speed of the phase unwrapping part can be increased. In order to overcome the disadvantages of the non-uniform PS points distribution and low coherence cavities, the Kriging interpolation method is used to get an uniform digital elevation model (DEM) eventually. This study proposed a GB-InSAR interferogram processing method. First, it proposes a PS point selection method considering both accuracy and efficiency. Second, the study shows a network programming phase unwrapping method to unwrap the PS points. Then, Kriging interpolation method is analysed and used to fill the low coherence cavities. Finally, a field test is carried out in an open pit in Hebei, China. The DEM result of the observation area is shown to verify the correctness of this study's method.