基于边缘检测的干涉SAR解相位模糊方法

Phase Unwrapping with Edge Detection for Interferometric SAR

相位解模糊是干涉合成孔径雷达三维成像的关键技术。基于边缘检测算法确定干涉图中干涉纹的位置来实现干涉相位的解模糊。为了提高干涉纹的检测精度 ,将纹线检测和纹线跟踪相结合 ,并采用了中值滤波和相对平均灰度梯度法进一步减小噪声。该方法具有无积累误差且稳定性好的优点。利用三峡地区的L波段SIR C并行轨道数据 ,运用上述方法实现了相位解模糊 。

A method for phase unwrapping of interferometric SAR is described in this paper. First SAR image edge detection techniques are used to find the location of the fringe lines in the interferometric phase image. In order to improve the accuracy of the fringe detection, median filter and the method of relative mean gradient of gray scale are used. Then the fringe detection and fringe tracking to improve the image are combined. Two thresholds, both high and low are used to detect the fringe. By the method for phase correcting by setting reference phase, some phase leap points are corrected. The method given in this paper has advantages of stability and less error. By using the L band data of SIR-C of the Three-Gorge area of China, the data of phase unwrapping is obtained by the method.