基于差异度的极化SAR相干斑抑制效果评估

相干斑抑制是极化SAR图像解译和信息提取的基础。针对采用极化特征图对极化SAR图像相干斑抑制算法极化信息保持能力定性评估的不足，本文提出一种基于差异度的相干斑抑制效果评估方法。该方法通过比较相干斑抑制前后目标区域的差异度，实现相干斑抑制算法对目标极化信息保持能力的定量评估。在评估过程中采用分别先对目标区域内每个像素做差异度后求平均的方法，代替传统的先将目标区域内像素K矩阵求平均后求极化特征图的方法，避免了先对各个像素做平均带来的二次估计。对通过极化特征图判断性能接近的不同相干斑抑制算法，得到更为精确的评估结果。最后选取三类典型相干斑抑制算法，分别对仿真数据和实测ESAR数据中的面目标和点目标进行评估，验证了方法的有效性。 

Effect Evaluation of Polarimetric SAR Speckle Filteing Based On Difference Degree

Speckle appearing in synthetic aperture radar(SAR) images is an inherent phenomena due to the coherent interference of waves reflected from many elementary scatterers.So speckle filtering is an important step for the extraction of meaningful information from SAR images.Foi polarimetric SAR(PolSAR),how to preserve polarimetric information effectively play a significant role in evaluating filters performance.In order to evaluate quantitively the preservation performance of polarimetric information for PolSAR speckle filters,the paper presents an effect evaluation method of PolSAR speckle filtering based on difference degree.This method compare for difference degree of polarimetric scatter matrix of targets area which from original and filtered PolSAR images.In evaluate process,adopt to averaging difference degrees from pixel to pixel on target area,instead of conventional method which always averaging Kennaugh matrices to calculate polarization signatures. This amelioration can avoid second estimate to Kennaugh matrices,not only achieve quantitative evaluation for the preservation performance of polarimetric information,but also obtain more accurate result of evaluation for speckle filtes which performance are similar evaluated by polarization signature.Finally,three typically PolSAR speckle filtes are used to filter simulate and real PolSAR data respectively.The experiment evaluate results of areas and point targets show that the proposed algorithm has the well theoretical and actual performance in effect evaluation of PolSAR speckle filteing.