Spectral Filtering for Repeat-pass SAR Interferometry
重复轨道InSAR处理中的频域滤波研究

In repeat-pass synthetic aperture radar interferometry,the decorrelation caused by azimuth and range spectral shifts leads to a deterioration of the quality of SAR interferogram.There is a need to put proper spectral filters on the main and slave images.The paper discusses a new spectral filtering procedure that performs filtering before and after fine coregistration according to spectral characteristics.The procedure will reduce spectral misalignment,improve the accuracy of fine coregistration,and at last obtain high quality of interfeorgram.Four pairs of ERS-1/2 SLC data with different time interval and nominal baseline are used to analyze the validity of our method.Results show that the average values of coherence after spectral filtering flow are higher than that before spectral filtering flow,moreover the amount of residues is highly decreased.These give evidence to the goodness of the procedure.