Photon counting polarization imaging strategy for target classification under photon-starved environments

Abstract Considering the requirements of long-range detection, eye safety and anti-reconnaissance, the detection of weak signal has become a research hotspot in the field of lidar. Gm-APD(Geiger-Mode Avalanche Photodiode) has extremely high response sensitivity and extremely high timing accuracy. At present, Gm-APD photon counting lidar system can obtain the 3D (Dimension) range image of target in the case of weak echo signals. However, considering the detection of obscured target, the 3D range image cannot distinguish which pixel point echoes come from the target and which come from the shelter, which will cause the target recognition to be blurred and uncertain. In this paper, a Gm-APD photon counting polarization imaging lidar system is proposed, which can simultaneously obtain the range and polarization information of the target under the condition of the extremely weak echo optical signals (the number of photons per pulse echo is much less than 1). Finally, the experimental system was built to image a model airplane shaded by tree branches, with an average of 0.01 photons per echo pulse, a clear image of model airplane is separated from the shelter according to polarization information.