Abstract:

Phase noise in the interferogram directly affects the result of phase unwrapping and the precision of interferometirc measurement. A novel approach combining the local frequency estimation with wavelet transform is presented to reduce interferometric phase noise for interferometric synthetic aperture radar (InSAR). According to the local frequency estimation result, the subband of wavelet coefficients containing useful information can be found out. Based on the fact that the VisuShrink method has effective noise reduction ability and the NeighShrink method performs well in detail preservation, the wavelet coefficients containing useful information are shrunk by the NeighShrink method while the others are shrunk by the VisuShrink method. As a result, the noisy interferogram can be efficiently filtered without destroying the fringes. The experiments using the simulated data and the real data demonstrate the validity of the proposed method.