DESIGN OF GABLE ROOF LCP FOR GEOMETRIC EVALUATION OF POINT-CLOUD

Abstract

This research study has designed a Gable-roof Lidar Control Plane (LCP) target for lidar applications to assess the positional accuracy of cloud points from a UAV laser scanner. The design involves creating ground control points in the form of Gable-roof Lidar Control Plane (LCP), which can be used to validate and calibrate the horizontal and vertical data of the point-cloud obtained from each strip of laser scanner during the strip-adjustment process. The research proposes the use of Python language software as a processing tool to calculate the position of the centroid of the roof target in order to determine control points in the strip-adjustment of LiDAR data processing steps. Two software tools have been developed, namely ChkStrip_LCP and Estim_LCP. The development of the ChkStrip_LCP software assists in verifying the number of ground control points falling onto each Lidar strip. The Estim_LCP software is developed to accurately calculate the representative hip coordinates of the point-cloud. The representative hip centroid coordinates of the roof target, which can be compared with the coordinates obtained using GNSS RTK. In the case study of lidar mapping with unmanned aerial vehicles equipped with the CHC AA450 laser scanning system in an approximately 1-square-kilometer area, the research found a horizontal deviation of 11 centimeters and a vertical deviation of 14 centimeters.