Conjugate point matching model for airborne lidar boresight misalignment calibration

Boresight misalignment of the airborne lidar system significantly leads to systematic offsets in the multi-strip point cloud, degrading the accuracy of surveying data. However, efficiency challenges remain for existing boresight calibration methods due to the stringent requirements for aircraft trajectory geometric configuration. Here, we propose, to our knowledge, a novel calibration method based on conjugate point matching, by extracting conjugate points from overlapping strips and applying a matching algorithm. The technique requires only two overlapping strips to calibrate boresight misalignment, significantly improving calibration efficiency. The accuracy and robustness of this method were validated through both simulated and field experimental data. Experimental results showed that after calibration, the planar fitting residuals decreased from 0.74 to 0.27 m, and the coordinate deviation of building contours was reduced from 4.07 to 0.37 m. This method is expected to provide new technical support for automated calibration technologies in airborne lidar systems.