A Locally Adaptive Filter for Noise Filtering of InSAR Interferogram
The article proposes an adaptive filtering approach for interferograms, which is a modification to the proposed filter. Based on local frequency estimates, we compute the window sizes of two directions and the normal orientation of local phase fringes. A directionally dependent filtering window is aligned perpendicular to the normal orientation of local phase fringes by interpolation,making the pixels included in the filtering window have more homogeneous values. This filter minimizes the loss of signal and reduces the level of noise. By using two sets of simulated data, the effectiveness of this filter is demonstrated by its capabilities in adaptive noise filtering, fringe preservation, and residue reduction.