Range dependent spectral filtering to minimize the baseline decorrelation in airborne SAR interferometry

This paper discusses two methods to solve the problem of a range-dependent baseline decorrelation occurring especially in airborne repeat-pass SAR interferometry. The first approach allows a fixed bandwidth filtering for the whole range avoiding the spectral misalignment of the standard method. The second approach enables a real adaptive filtering of the range-dependent baseline decorrelation and allows one also to obtain the best geometric resolution for each range position without decreasing the interferogram coherence. The efficiency of the two methods is demonstrated by using interferograms obtained from DLR's E-SAR in the L-band repeat-pass-mode.