Fluctuations of light intensity scattered from multiple glints in atmospheric turbulence

摘要

As targets in space are usually very far from the ground, some targets containing smooth reflecting components can be seen to be composed of a single or multiple glints when they are detected by a Lidar (laser radar) system located on the ground. The received intensity of the detector fluctuates, which caused significant noise on the system, for two reasons. One is the randomness of positions of the glints and the other is the perturbations of the atmospheric turbulence. The formulation of the scintillation index of the reflected intensity is derived by using incoherent superposition of the reflected field. The results show that the scintillation index can be divided into two parts, corresponding to the two sources that cause the intensity fluctuations. The results show that the target composed by multiple glints has two different effects on the fluctuation of the reflected intensity, one is the amplification effect of the incoherent superposition, and the other is some similar aperture averaging effect.