The authors propose an improved sigma filter for the speckle filtering of polari-metric interferometry data. The Lee sigma filter was developed in 1983 based on the simple concept of two-sigma probability, and it was reasonably effective in speckle filtering. However the speckle model used in Lee sigma filter is the negative exponential model, which is only suitable for uniform regions. For the texture and very uneven regional areas, the effectiveness of this filter is to be questioned. In this paper, we extend and improve the Lee sigma filter by introducing generalized Gamma model, which can be applied to a variety of areas. In addition, we incorporate the phase processing to improve the interferometric coherence. The proposed algorithm is applied to Chinese airborne SAR data to demonstrate its overall speckle filtering characteristics as compared with other algorithms.
展开▼
