基于STFT的INSAR干涉图自适应零中频矢量滤波

提出了一种基于短时傅立叶变换的合成孔径雷达干涉图自适应零中频矢量滤波方法。该方法将干涉图映射至矢量空间,并采用短时傅立叶变换进行局域频谱分析,统计得到各局域的中心频率;然后频率自适应地建立参考干涉图序列,并将原始干涉图与参考干涉图序列进行差分处理,得到零中频干涉图序列;最后对零中频干涉图序列进行矢量滤波,由滤波后的零中频干涉图序列和参考干涉图序列得到原始干涉图的滤波结果。实验结果表明:该方法能够解决干涉条纹密集、干涉条纹频率变化较大处滤波效果差的问题。

Adaptive ZIF Vector Filter for INSAR Interferograms Based on STFT

A new Adaptive Zero Intermediate Frequency Vector filtering algorithm for interferograms of Interferometric Synthetic Aperture Rada rwas proposed based on Short Time Fourier Transform. The raw interferogram was mapped to unit vectors. And the vectors were analyzed by Short Time Fourier Transform to get local Intermediate Frequencies of the interferogram. Then the reference interferograms in sequence were derived from the Intermediate Frequencies adaptively. The Zero Intermediate Frequency interferograms in sequence were obtained by differencing the raw interferogram and the reference ones. The Zero Intermediate Frequency interferograms were filtered by vector filter. And the filtered result of the raw interferogram was calculated by the filtered Zero Intermediate Frequency interferograms and the reference interferograms. Experiments show that the proposed filtering algorithm can resolve the difficulty in dealing with interferograms with dense fringes and with fringes whose frequency changes greatly.