Modeling and simulation of laser active imaging system based on APD detector

Abstract

The laser active imaging system is widely focused from all over the world owe to the high resolution of angle, range, velocity, the wide range of velocity measurement, the angle-range-gray-velocity information of target, the finitely ability of anti-stealthy. The laser active imaging system based on high sensitivity Avalanche Photo Diode (APD) detector is the main development direction because of remote imaging distance, simple structure and minimization. However, the performance of the laser active imaging system based on APD is seriously affected by many factors, and the relationships between system’s Signal-to-Noise Ratio (SNR) and influence factors are not further studied. In this paper, the modeling and simulation of SNR for the laser active imaging system based on APD is presented. The theory of the laser active imaging system is shown firstly, and the model is derived by means of deducing laser illuminating according to the principle of laser radar. And then, the sources of noise are analyzed by accurately modeling all noise sources in the detection system, the SNR equation of the laser active imaging system is founded. Finally, the relationships between SNR of system and influence factors such as receive optics aperture and amplification ratio are discussed, and correspondingly the improvement is put forward.