Because of the backscatters, SAR images are contaminated by speckle noises which lower image quality and mask image structure.Therefore, noise-smoothing is the first step in the image processing.

• SAR的后向散射成像机制决定了SAR图像中存在相干斑噪声，这些相干斑噪声降低了图像质量，掩盖了图像的细节结构，因此在SAR图像处理时通常先对图像进行去噪。