Abstract: In the urban environment with tall buildings and dense trees, the GNSS signals are susceptible to occlusion, and the position error of the POS composed of GNSS/INS accumulates rapidly. This leads to an increase in the coordinate errors of vehicle-borne laser point clouds computed from the position attitude data provided by the POS. Additionally, the point cloud shows localized non-rigid deformation phenomena. To solve the above problems, based on the traditional POS-based point cloud correction method, this paper further studies the complex urban environment with GNSS signal occlusion and vehicle operation conditions. Through comparing the spacing of different control points, it formulates the optimal deployment scheme for control points. The error characteristics of POS under different GNSS signal occlusion conditions are deeply analyzed so as to construct a reasonable error time-varying interpolation model. The control point error interpolation information is utilized to correct the POS position to provide reliable position information for the vehicle-borne laser point cloud solving. The experimental results show that the positioning accuracy of the POS corrected using the strategy of this paper can be improved by about 62.50% compared with the pre-correction one. The accuracy of the corrected point cloud solved using the corrected POS position can be improved by about 75.45% compared with the pre-point cloud correction one.

Key words: urban complex environment, POS, error interpolation, vehicle-borne laser point cloud, point cloud correction