Multiplication Model and Filtering of Speckle Image in Laser Imaging Radar System

In recent years, many countries and research institutions have carried out a lot of research on the application of remote high resolution imaging. Synthetic Aperture Laser Imaging Radar (SAR) is the only active imaging method that can achieve remote imaging resolution of cm scale at present. In recent years, many countries and research organizations have obtained target reconstruction images of 2D SAR imaging radar. However, in all the target images obtained, the laser speckle effect seriously reduces the quality of the reconstructed images. Laser speckle in synthetic aperture laser imaging radar is different from the traditional laser speckle in the past and belongs to dynamic space-time speckle. In the fast time scale, the laser speckle varies with the linear frequency modulation of the laser emission wavelength. In the slow time scale, the laser speckle changes with the relative motion of the lidar. Therefore, it is of great significance to study the mechanism of laser speckle generation and its countermeasures.