Coherent imaging methods like synthetic aperture radar (SAR) are subject to speckle, and the suppression of this noise-like quality is often considered a prerequisite to image interpretation. Likewise, circumstances such as frequency jamming or system multiplexing produce gaps in the data and corresponding image artifacts, which further impact the utility of resulting imagery and induce correlation in the speckle process. For multi-channel SAR configurations such as the polarimetric or interferometric modes, a Bayesian imaging procedure is proposed to harvest the benefits of jointly processing channels in order to recover scattering information. The inference technique recovers the per-pixel multi-channel SAR covariance and incorporates a statistical model of speckle and a priori knowledge of the varieties of clutter present in the scene. Further, by combining speckle reduction into the image formation process for gapped aperture measurements, the estimator can balance competing objectives of image resolution, side-lobe suppression, texture preservation, and speckle reduction. An expectation-maximization algorithm is made computationally tractable by a graph-coloring probing technique to provide the block-diagonal portion of a large matrix inverse. Recovery results with simulated and measured fully polarimetric airborne SAR data indicate that the proposed method reduces the appearance of speckle and preserves spatial resolution.

中文翻译：

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多通道相干成像中的斑点抑制：一种易于处理的贝叶斯方法

合成孔径雷达 (SAR) 等相干成像方法容易受到散斑的影响，抑制这种类似噪声的质量通常被认为是图像解释的先决条件。同样，频率干扰或系统多路复用等情况会在数据和相应的图像伪影中产生间隙，这进一步影响所得图像的效用并在散斑过程中引起相关性。对于偏振或干涉测量模式等多通道 SAR 配置，提出了贝叶斯成像程序来收获联合处理通道的好处，以恢复散射信息。推理技术恢复每像素多通道 SAR 协方差，并结合散斑统计模型和场景中存在的各种杂波的先验知识。更多，通过将散斑减少结合到间隙孔径测量的图像形成过程中，估计器可以平衡图像分辨率、旁瓣抑制、纹理保留和散斑减少的竞争目标。通过图着色探测技术使期望最大化算法在计算上易于处理，以提供大矩阵逆的块对角线部分。模拟和测量的全极化机载 SAR 数据的恢复结果表明，所提出的方法减少了散斑的出现并保持了空间分辨率。通过图着色探测技术使期望最大化算法在计算上易于处理，以提供大矩阵逆的块对角线部分。模拟和测量的全极化机载 SAR 数据的恢复结果表明，所提出的方法减少了散斑的出现并保持了空间分辨率。通过图着色探测技术使期望最大化算法在计算上易于处理，以提供大矩阵逆的块对角线部分。模拟和测量的全极化机载 SAR 数据的恢复结果表明，所提出的方法减少了散斑的出现并保持了空间分辨率。