Research on detection performance improvement of polarization GM-APD LiDAR with adaptive adjustment of aperture diameter and spatial correlation method

Abstract

The triggering probability of GM-APD (Geiger-mode avalanche photodiode) is affected by the absolute signal intensity and the SNR (Signal-to-Noise Ratio). Through investigation, the polarization detection can effectively enhance the signal’s triggering probability by increasing the signal’s SNR; however, the triggering probability cannot reach the highest value at a certain SNR. In this paper, the polarization detection with the adaptive adjustment of aperture diameter (AAAD) and spatial correlation method was proposed to enhance the detection results, which could help to get the highest triggering probability, and the signal detection performance was obviously improved. Firstly, the theoretical model of the polarization detection with AAAD was built. Secondly, the effects of factors such as noise intensity, range, SNR, etc. on the triggering probabilities of the non-polarization detection, the polarization detection and the polarization detection with AAAD were analyzed; the theoretical analysis showed that the polarization detection with AAAD could effectively increase the triggering probability and the detection probability; besides, by introducing the spatial correlation method, the detection probability could be improved in a further step. Finally, the experimental verifications were carried out in the low SNR surroundings, the results showed that the combination of the polarization detection with AAAD and spatial correlation could enhance the signal detection probability by 80.8% of the initial detection probability, and the target restoration ratio could reach 96.9%. The research in this paper improves the daytime detection performance to a large extent, and it is very useful for the actual application of GM-APD LiDAR.