Speckle Filtering of Polarimetric SAR Interferometry Data

摘要

Recently, polarimetric SAR interferometry has generated much interest for forest applications. Tree heights and groundrntopography can be extracted based on interferometric coherence using a random volume over ground coherent mixturernmodel. The coherence estimation is of paramount importance for the accuracy of tree height estimation. The coherencern(or correlation coefficient) is a statistical average of neighboring pixels of similar scattering characteristics. Therncommonly used algorithm is the boxcar filter, which has the deficiency of indiscriminate averaging of neighboringrnpixels. The result is that coherence values are lower than they should be. In this paper, we propose a new algorithm tornimprove the accuracy in the coherence estimation based on speckle filtering of the 6x6 polarimetric interferometryrnmatrix. Simulated images are used to verify the effectiveness of this algorithm. L-Band DLR ESAR data are used torndemonstrate the improved accuracy in coherence and in tree height estimation.