Redundant Data Removal Method Between Laser Radar Lanes

Apr 20, 2023

When airborne lidar technology acquires point cloud data, due to the limitation of scanning field of view and altitude, it usually needs to fly multiple routes. A certain degree of lateral overlap needs to be set between these routes to ensure that data collection can cover the entire survey area. Since these side overlapping areas will be covered by the point clouds of the two strips, the density is greater than other areas, so data redundancy will be formed in the overlapping areas, which will lead to non-uniform spatial distribution of laser point clouds, and LiDAR data in the strips The accuracy of point cloud data with edges is poor, and removing redundant data is an important step in the later stage of LiDAR data processing and product production.

Figure1: Point Cloud Preprocessing Data Before Eliminating Redundancy

Generally, the measurement error of the laser point is proportional to the laser scanning angle. The closer to the edge of the strip, the greater the error of the point cloud. For the redundant part of the overlapping area of the laser radar strip, use the cut-overlap function of the Terrasolid software, according to the complete route Information, based on the theoretical basis that the point cloud accuracy decreases with the increase of the scan angle, so as to remove the point cloud with a larger flight scan angle in the overlapping area of the flight belt, and retain the points with higher quality close to the center of the flight belt, which can effectively eliminate the Data redundancy between bands.

 Figure2: After Point Cloud Preprocessing Data Eliminates Redundancy