A silicon photomultiplier (SiPM) LiDAR with photon threshold detection can achieve high dynamic performance. However, the number fluctuations of echo signal photons lead to the range walk error (RWE) in SiPM LIDARs. This paper derives the RWE model of SiPM LiDAR by using the LiDAR equation and statistical property of SiPM’s response. Based on the LiDAR system parameters and the echo signal intensity, which is obtained through the SiPM’s photon-number-resolving capability, the RWE is calculated through the proposed model. After that, we carry out experiments to verify its effectiveness. The result shows that the method reduces the RWE in TOF measurements using photon threshold detection from 36.57 cm to the mean deviation of 1.95 cm, with the number of detected photons fluctuating from 1.3 to 46.5.

Flash LiDAR is a photoelectric system that can acquire a 3D image by emitting a diffuse pulsed laser beam, and hence is suitable for both autopilot and spacecraft flight control. Achieving long-range and high-speed, especially in outdoor applications with strong solar background illumination, are challenging requirements. In this paper, a set of laser imaging prototype based on 2×6 VCSEL array and 32×32 MPPC array image sensor is developed, the range calibration is completed, and relevant experimental research is carried out. The frame rate of the system can reach 10kHz, the detection probability of 120m range can reach 86.23%, and the maximum walk error is about 0.6m under different reflectivity. The 3D imaging of the vehicle can be realized at about 70m, the horizontal spatial resolution is less than 5cm, and the ranging precision after ten shots average is within 10cm by calculating the centroid of a histogram. The detection probability can be improved by using the time-gating method. After multiple measurements, a 120m “laser imaging through window” can be realized in sunlight. This LiDAR system has the advantages of small volume, light weight and fast detection speed.

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