Analysis on the Influences of Range-gated Underwater Laser Imaging System Parameters on the Signal to Noise Ratio

摘要

Range-gated underwater laser imaging system is a kind of underwater photoelectric imaging system which is based on the principle of time label for target. Through controlling the imaging time of photoelectric equipment precisely, it can effectively restrain the backscatter of water, having longer detective distance than generic ones. A range-gated underwater laser imaging system consists of pulse laser illumination system, photoelectric imaging system (ICCD) and control system commonly. When the moment and the time of ICCD opening gate are given, the lights that could be received by ICCD include the backscatter of water, the direct component and forward scatter of reflected light of the target in the imaging processing of range-gated underwater laser imaging system. Computing model of light energy received by ICCD was built in this paper. The direct component and forward scatter of reflected light energy were analyzed and the calculation methods based on PSF theory were studied. The backscatter light energy of water was calculated through water layering. The signal to noise ratio of range-gated underwater laser imaging system was defined. The impact of target range, target reflection ratio, ICCD gating width and water attenuation coefficient on the signal to noise ratio were analyzed and simulation results were given.