Spatial Calibration of Diffuse LiDARs

TL;DR

This paper introduces a spatial calibration method for diffuse LiDARs that estimates per-pixel footprint and sensitivity, enabling accurate alignment with RGB images for improved cross-modal fusion.

Contribution

A novel calibration procedure for diffuse LiDARs that estimates per-pixel response maps and spatial correspondence with RGB images.

Findings

Effective calibration on ams OSRAM TMF8828 LiDAR.

Enables accurate LiDAR-RGB cross-modal alignment.

Improves fusion quality for diffuse LiDAR data.

Abstract

Diffuse direct time-of-flight LiDARs report per-pixel depth histograms formed by aggregating photon returns over a wide instantaneous field of view, violating the single-ray assumption behind standard LiDAR-RGB calibration. We present a simple spatial calibration procedure that estimates, for each diffuse LiDAR pixel, its footprint (effective support region) and relative spatial sensitivity in a co-located RGB image plane. Using a scanned retroreflective patch with background subtraction, we recover per-pixel response maps that provide an explicit LiDAR-to-RGB correspondence for cross-modal alignment and fusion. We demonstrate the method on the ams OSRAM TMF8828.