Influence of space-time speckle effect on the image quality in a synthetic aperture imaging ladar

Temporally and spatially varying speckle effect arises as a consequence of the frequency modulation chirped laser signal employed in synthetic aperture imaging ladar (SAIL).A variety of reconstructed images degraded by laser speckle effect have been reported. In this paper, space-time speckle effects and their influence on imaging based on the SAIL system in a far-field diffraction region are systematically studied. The first half of this paper provides the theoretical analyses of the 2D data acquisition with speckle effect in SAIL. Numerical simulations of the temporally varying speckle pattern, the integrated speckle field over a receiving antenna and their influence to the image quality for SAIL are obtained in the remaining of the paper. Our results will be valuable for further studies on the suppression of speckle effect in SAILs.