A method to reduce the phase undersampling effects in airborne INSAR

In SAR interferometry (INSAR), the effectiveness of the phase-unwrapping algorithms is prejudiced by phase aliasing and geometrical phenomena, such as layover and shadowing, which cause unwrapping errors and significant degradation of the height estimates. The many algorithms proposed are affected by the same problem: a local error spreads over large areas of the interferogram, causing a global error. We present a method which improves the performances of the unwrapping algorithm by detecting and marking the phase undersampling and layover areas. We also present a statistical model of an INSAR used to generate the interferogram and evaluate the altitude error of the proposed method.