Research on GM-APD lidar simulation model for complex scene detection

With single-photon sensitivity and nanosecond-level time resolution, Geiger-mode Avalanche Photodiode (GMAPD) Lidar exhibits tremendous potential in the long-range detection of weak and small targets. However, the high manufacturing cost, limited imaging resolution, and stringent requirements of long-distance experimental setups have significantly hindered theoretical advancements. To address these challenges, this paper proposes a full-link echo simulation model based on the GM-APD Lidar triggering principle. The model systematically integrates sensor parameters, 3D scene scattering characteristics, optical transmission mechanisms, and target motion behavior, providing theoretical support for imaging, dynamic target recognition, and modeling long-range weak echoes in complex environments. Based on this model, a hardware-in-the-loop simulation platform is developed using the Unity engine, enabling the simulation of diverse, complex environments (e.g., urban, forest, ocean, and high-altitude) and various dynamic targets. The platform supports gated imaging at resolutions ranging from 64 to 512 levels and can simulate detection distances up to 500 km. Experimental results demonstrate that the simulation platform outperforms actual GMAPD systems in terms of simulation accuracy and data consistency, thereby significantly reducing experimental costs and enhancing research efficiency. This work offers valuable theoretical insight and strong application potential.