中文摘要：

在经典的极化分类Wishart距离基础上，提出一种对变化敏感的极化距离测度，发展了相应的多时相极化SAR变化检测方法。以北京地区的多时相全极化RADARSAT-2影像进行了试验，对比分析提出的极化距离测度与各个极化通道后向散射系数对数比值对不同类型地物变化的区分能力。结果表明，提出的极化距离测度不仅对所有的变化类型均有良好的检测作用，而且对变化区域有更高的区分力。

英文摘要：

A new distance measure derived from the polarimetric coherency matrix is proposea on the basis of classical Wishart distance originally developed for polarimetric SAR image classifi- cation. A change detection methodology based on the proposed distance measure is then devel- oped. An experiment of change detection using two RADARSAT-2 quad-polarized images acquired in 2009 and 2010 respectively over a suburb area of Beijing is carried out. The change detection capability of the polarimetric distance measure is compared to the log-ratio images formed by the radar intensities of different polarization channels and the total scattered power （the Span）. The results show that the polarimetric distance measure can detect all types of land cover changes, while only some of the change types can be discriminated from intensity-related log-ration images. Moreover, the difference image generated from the polarimetric distance presents highest separability between changed and unchanged pixels.