Blind Speckle Decorrelation for SAR Image Despeckling
Blind Speckle Decorrelation for SAR Image Despeckling
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DOI：
10.1109/tgrs.2013.2246838
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发表时间：
2014-02
影响因子：
8.2
通讯作者：
A. Lapini;T. Bianchi;F. Argenti;L. Alparone
中科院分区：
文献类型：
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作者：
A. Lapini;T. Bianchi;F. Argenti;L. Alparone
在过去的几十年里，已经发展了几种方法来消除合成孔径雷达（SAR）图像的斑点。其中相当一部分是在充分发展的散斑模型的假设下推导出来的，其中乘法散斑噪声被认为是一个白过程。不幸的是，SAR捕获系统的传递函数会引入统计相关性，从而降低了这种滤波器的去斑效率。针对SAR系统采集的复杂图像，提出了一种白化处理方法。我们证明了所提出的方法可以成功地应用于经典的去斑算法。首先，我们根据所获取图像的一些统计特性并使用现实假设对SAR系统的频率响应进行估计。然后，考虑点目标的存在，对获取的图像进行去相关处理。最后，对图像进行去斑处理。实验结果表明，采用本文提出的白化方法后的去斑滤波效果更好；此外，还保留了图像的辐射特征。
In the past few decades, several methods have been developed for despeckling synthetic aperture radar (SAR) images. A considerable number of them have been derived under the assumption of a fully-developed speckle model in which the multiplicative speckle noise is supposed to be a white process. Unfortunately, the transfer function of SAR acquisition systems can introduce a statistical correlation, which decreases the despeckling efficiency of such filters. In this paper, a whitening method is proposed for processing a complex image acquired by a SAR system. We demonstrate that the proposed approach allows the successful application of classical despeckling algorithms. First, we perform an estimation of the SAR system frequency response based on some statistical properties of the acquired image and by using realistic assumptions. Then, a decorrelation process is applied on the acquired image, taking into account the presence of point targets. Finally, the image is despeckled. The experimental results show that the despeckling filters achieve better performance when they are preceded by the proposed whitening method; furthermore, the radiometric characteristics of the image are preserved.