Mixed Centroid Method for Spaceborne Laser Altimeter Calibration

The on-orbit calibration of spaceborne laser altimeters is based on traditional geometric calibration in which the laser pointing angle error is the primary evaluation index. This study proposes a mixed centroid method for calculating the laser footprint center by using the geometric center of each energy level eliminating the abnormal energy level points, inverting the laser energy level distribution, and correcting the true footprint. Then, the mixed centroid method is compared with the traditional geometric center method and the centroid method. Simulation comparisons demonstrate that the proposed method offers high precision and low calibration cost, thereby improving the calibration accuracy of the target. The proposed method provides a reference algorithm for the ground field calibration of the next generation of high-resolution mapping satellites in China.