Improved weighted least-squares phase unwrapping method for interferometric SAR processing

Based on the study of existed least-squares and weighted least-squares phase unwrapping methods, an improved weighted least-squares algorithm based on unwrapping phase error compensation is proposed. First, the conventional weighted least-squares method is used to get the initial result of phase unwrapping. Then the unwrapping result is optimised by iterative compensation of phase unwrapping error. In addition, for the reasonable selection of the times of iteration, an iterative mechanism is designed to avoid the redundant or insufficient compensation caused by too many iterative times and too few. Compared with the traditional weighted least-square method, by using the proposed method, the global influence of phase noise is constrained by weighted processing, and meanwhile, the accuracy of phase unwrapping is greatly improved by iterative error compensation. The simulation results confirm the superiority of the proposed method.