利用BEMD-自适应滤波去除SAR干涉图噪声

Interferogram Denoising Method Based on BEMD and Adaptive Filter

基于二维经验模态分解特性,提出了一种基于BEMD-自适应滤波的干涉图抑制噪声算法,并对自适应滤波的窗口进行了改进。根据窗内特征自适应调节窗口大小,并通过门限来决定是否需要改变窗口尺寸,达到在同性质区增大窗口来抑制噪声,在异性质区减小窗口以最大限度地保护图像细节的目的。实验表明,该算法不仅能有效地抑制干涉图的噪声,增强滤波的局部自适应性,而且能很好地保持条纹的细节信息。

A new adaptive filter based on empirical mode decomposition based on different characteris- tics of signal with noise in different IMFS for suppressing speckle in SAR interferograms is proposed. At first, empirical mode decomposition is used to divide signal and processed high-frequency IMF sig- nals separately by adaptive filtering The denoising effect of the proposed method, the usual filter and a multiscale BEMD filter were investigated by experiment. When the part related to the speckle is subtracted from the original interferogram, speckle noise is reduced. The results are compared with the four other methods of mean filtering, median filtering, BEMD decomposition method and the ordi- nary adaptive filtering, showing that the BEMD-adaptive filter method is a powerful means for inter- ferogram speckle noise reduction, and can preserve fine details in the interferogram directly related to the ground topography as well as maintain phase values distribution.