Range walk error correction for MPPC array-based high-precision 3D imaging

The multi-pixel photon counter (MPPC) array-based 3D imaging is a promising technology for remote sensing. However, variations in target reflectivity can introduce range walk error (RWE) during threshold discrimination, limiting imaging performance. This paper proposes an efficient RWE correction method for MPPC array, which combines threshold voltage modulation and macro-pixel linear regression. Using single-frame images obtained at four different threshold voltage, the method reduces the depth difference between high and low reflectivity regions of planar targets from 76.51 cm to 1.17 cm (98.47% reduction). Incorporating multi-frame techniques further reduces the depth difference to less than 0.69 cm. The method also demonstrates superior correction performance for non-planar targets, significantly improving 3D imaging accuracy. These results validate the effectiveness of the proposed method and enhance the robustness of MPPC array under fluctuating echo energy conditions. This provides crucial technical support for long-range detection in complex environments.