Improvement of detection probability and ranging performance of Gm-APD LiDAR with spatial correlation and adaptive adjustment of the aperture diameter

• Published in: Optics and lasers in engineering 2021-03, Vol.138, p.106452, Article 106452
• Main Authors: Zhou, Xin, Sun, Jianfeng, Jiang, Peng, Qiu, Changrui, Wang, Qi
• Format: Article
• Language: English
• Subjects: AAAD; Gm-APD; Ranging walk-error correction; Spatial correlation
• ISSN: 0143-8166; 1873-0302
• DOI: 10.1016/j.optlaseng.2020.106452

•The combination of spatial correlation and AAAD detection scheme is first implemented in the Gm-APD LiDAR.•The theoretical triggering and ranging performance models of the proposed detection scheme of Gm-APD LiDAR is first proposed.•A MLE-based ranging walk-error correction method is first proposed.•The proposed detection scheme effectively improves the target's detection probability with the limited amount of measurements in the daytime.•The proposed ranging walk-error correction method effectively suppresses the walk-error with the limited amount of measurements in the daytime. Gm-APD (Geiger-mode avalanche photodiode) is widely used in the LiDAR (Light detection and ranging) system for its excellent photon detection capability. The triggering probability of Gm-APD is closely dependent on the absolute intensity and the signal-to-noise ratio (SNR) of the echo, which limits the detection results in the daytime. In order to improve target's detection probability under a limited amount of statistics in the daytime, it proposed a detection scheme by using the spatial correlation and adaptive adjustment of the aperture diameter (AAAD) to achieve optimal target detection results in the daytime, besides, a MLE (Maximum Likelyhood Estimation) based ranging walk-error correction method was also put forward for the limited number of measurement. Firstly, considering the strategies of AAAD and spatial correlation, as well as the LiDAR ranging equation and Poisson triggering probability model, the detection probability model and ranging performance model of the scheme of spatial correlation and AAAD were built in this paper. Subsequently, the detection probability and ranging performance of the proposed scheme were theoretically analyzed, besides, a ranging walk-error correction strategy was put forward based on the MLE method. The theoretical analysis results showed that the proposed detection scheme could increase the utilization of echo photons and improve the amount of echo's triggering statistics; moreover, the Monte Carlo simulation results showed that in the case of a limited amount of statistics, the target detection scheme and ranging walk-error correction strategy could effectively improve the target detection probability and obtain a smaller ranging walk-error than the traditional detection scheme. Finally, the Gm-APD LiDAR was used to experimentally verify the proposed scheme, and the results showed that the scheme could effectively improve the echo's tr