Spatial Calibration of Diffuse LiDARs
This addresses a calibration challenge for cross-modal fusion in robotics or autonomous systems, but it is incremental as it adapts existing calibration concepts to a specific LiDAR type.
The paper tackled the problem of calibrating diffuse LiDARs, which violate standard assumptions due to their wide field of view, by developing a spatial calibration procedure to estimate per-pixel footprints and sensitivity in RGB images, demonstrating it on the ams OSRAM TMF8828 device.
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.