A REVIEW OF POLARIMETRIC SAR SPECKLE FILTERING

In this paper, the recent advancement of PolSAR filtering is reviewed. Speckle filtering is a necessary procedure for most of PolSAR applications, to reduce speckle noise level and to form incoherent scattering by averaging coherency or covariance matrices of neighboring pixels. In this paper, we addressed several important but often ignored issues associated with PolSAR speckle filtering, and the recent very high resolution SLC PolSAR data demands special consideration in speckle filtering. The conclusion, we have reached, is that the best filter does not exist, because the desired filtering is determined by application requirements and personnel preference. A filter may be good for one application, but could be undesirable for other applications. In other words, speckle filtering is not an exact science, and the perfect speckle filtering cannot be achieved.