Georeferencing with Self-Calibration for Airborne Full-Waveform Lidar Data Using Digital Elevation Model

Abstract

Precise georeferencing of airborne full-waveform lidar is a complex process. On one hand, no ground control points are visible due to heavy canopy. While on the other hand, precise georeferencing relies on ground control. As an alternative, we propose to use an available digital elevation model (DEM ) as control. The mathematical framework minimizes the difference between the lidar DEM and the reference DEM. Our solution consists of two steps: initial optimization to find reliable ground points through iterative filtering and georeferencing, and fine optimization to achieve precise georeferencing and lidar system calibration. Through this approach, the wave-form-derived DEM can best fit the reference DEM, with a mean of 0.937 m and standard deviation of 0.792 m, while the time-synchronization offset and boresight angles are simultaneously determined, i.e., self-calibrated. This development provides a novel georeferencing approach with self-calibration for lidar data without using conventional ground control points.