基于小波包变换的SAR干涉图去噪研究

基于SAR复干涉图中噪声满足加性噪声模型,提出对复干涉图实部和虚部分别应用小波包软阈值方法的去噪方案。以Daubeachies小波为小波包基函数,对添加了噪声的模拟SAR干涉图进行去噪实验,发现三级小波包分解的去噪效果明显优于一级和二级分解。并进一步对实际的含噪干涉图进行了去噪实验,与小波包软阈值方法直接对干涉图去噪的结果进行了比较。实验结果证实了本文方案的有效性。

Noise Reduction for SAR Interferograms Based on Wavelet Packet Transform

Based on the noise in the complex interferograms satisfying an additive noise model,a noise reduction scheme using wavelet packet soft thresholding method to respectively remove the noise in the real and imaginary part of the complex interferograms is proposed.A denoising experiment has been performed through a simulated SAR interferogram contaminated by noise,adopting Daubeachies wavelet as the base function of wavelet packet transform.It is shown that the noise reduction effect of three-level wavelet packet decomposition obviously outperforms that of one-level and two-level wavelet packet decomposition.Moreover,a denoising experiment result has been achieved using a practical interferogram including noise with the proposed scheme,and has been compared with that obtained by directly processing interferogram employing wavelet packet soft thresholding method.The experiment results demonstrated the validity of the scheme proposed by this paper.