用于干涉合成孔径雷达的地形适应K-均值滤波器

研究了干涉合成孔径雷达干涉图的自适应相位降噪滤波问题。由于原有的基于局部统计特性的自适应滤波方法使用固定窗口长度,滤波对干涉条纹中的高频分量有较大损失,因此将K 均值自适应滤波方法运用于干涉图,提出了一种新的地形适应的K均值自适应滤波方法,新方法结合K均值滤波窗口尺寸以当前区域自身的方差为调节的优点,又针对干涉图相位方差的特点,区分噪声因素和地形变化对相位方差产生的不同影响,在抑制噪声的同时,保持了干涉条纹密集区的信息特征,具有更好的滤波效果。

Terrain adapted K-average adaptive filter in InSAR

The problem of adaptive noise reduction filtering in interferometric synthetic aperture radar(InSAR) is studied. Since the fixed window size is used in the present local statistics adaptive filter, the high frequency information of the fringe will be lost. A terrain adapted K-average adaptive filter is proposed to deal with such a problem. The method is based on the fact that the window size of the K-average adaptive filter can be changed with the variance of the image. The phase variance in the interferogram is from two different sources: noise and terrain change, so the variety of topography may be regarded as noise in K-average adaptive filter. The new method can distinguish different sources of variance. Therefore it can suppress noise and keep the information in dense fringe areas at the same time.