Airborne LiDAR Strip Adjustment Based on Least Z-Difference Algorithm

An airborne LiDAR system is an integration of GPS, INS and laserscanner. Because of errors of these instruments or sub-optimalities of the GPS/INS integration, points of neighboring laserscanner strips will usually show vertical and horizontal discrepancies. They can be corrected in a strip adjustment procedure. In this paper, least z-difference algorithm (LZD) is applied to the LiDAR strip adjustment. It estimates the transformation parameters between different strips, using the Generalized Gauss-Markoff model, minimizing the separation between the surfaces along the Z axis. Real data sets are used to validate the method. We study the need for using Gauss-Markoff model and the matching accuracy of our algorithm. Experimental results show that after correction the point clouds show much better alignment and the vertical matching error is less than 0.05m for idea data, while poor quality data the error is slightly larger.