But SAR image is liable to be affected by speckle noise, while almost spectral image have shortcomings of low contrast between object and background, edge blurring.
但SAR图像容易受到相干斑噪声的影响，而光谱图像普遍存在目标与背景对比度差、边缘模糊的缺点。
2
Based on the theory of laser speckle, a new method to measure the angular vibration of object by the laser speckle is suggested in this thesis.
本文在现有的散斑理论基础上，提出了一种利用激光散斑实时测量目标散射面角振动的新方法。
3
Speckle images are produced by the reflected and scattered light beams from rough surface through free-space to observing plane when laser illuminates the object surface.