Study of single photon echo detection technology in underwater target ranging

摘要

Because laser is scattered and attenuated acutely by the water ,diffuse reflection of Gauss laser pulse comes back with discrete single photon. These discrete single photon can not form a complete echo wave corresponding to original laser wave. The detector can only output discrete pulses with probability of η(quantum efficiency). The discrete pulses caused by echo wave, background light, electron hot emission of detection do not have distinct different characteristics in time domain or frequency domain, so echo wave can not be distinguished from these discrete pulses by traditional detection method. Through analysinge the signal and nosie statistic characteristics., we put forward a method that apply known probability model to detect probabilistic echo signal to resolve the problem hereinbefore mentioned images The signal is very low in underwater laser ranging, so it is very difficult to recognize the echo wave. This paper introduces n method and uses it to process the signal, digital threshold detection is simulated with laser ranging radar and we get good results. This study will help to greatly improve the ability of laser ranging radar.