Study On Phase Filtering And Two-dimensional Phase Unwrapping Techniques For InSAR System

Based on SAR systems, synthetic aperture radar interferometry (InSAR) is an important technique in remote sensing for the estimation of three-dimensional terrain images with height accuracy and high spatial resolution. InSAR has been placed on great emphasis for its wide and potential applications in many areas such as military, civil and scientific researches.This dissertation studies thoroughly on the techniques of InSAR, especially interferometric phase noise filtering and phase unwrapping, two key processing procedures. The history and the development of InSAR are reviewed first. Then the dissertation introduces the principles of the DEM reconstruction and summarizes the processing procedures of InSAR. In the following discussion of interferometric phase noise filtering, two classic methods are presented and a new phase filtering method is present. Moreover, this dissertation analyzes the principles of phase unwrapping and classifies the existing methods for phase unwrapping. In the mean time, different methods such as branch cut, quality map oriented phase unwrapping and Least-squares two-dimensional phase unwrapping using FFT are compared. The advantages and limits of them are separately summarized. At last, a new method based on branch cut and coherence quality for phase unwrapping is introduced.