Research on Motion-to-Motion Relative Positioning Algorithm of BDS/GPS Inside the Tree-Lined Road Based on DEM Elevation Constraint
Aiming at problems such as satellites in the tree-shaded section is seriously occluding or frequently occluding,the observation quality is poor,the geometric strength is not good,the coordinate floating point solution is not estimated accurately in the positioning process,the observation value frequently occurs cycle hop,and the ambiguity can not be solved,a BDS/GPS double system combination positioning method based on DEM elevation constraint is proposed.The number of visible satellites is increased by BDS/GPS combi-nation positioning,the accuracy of carrier position prediction is improved by Kalman filter and DEM elevation constraint,thus the accuracy of floating point solution estimation is im-proved,and the fixed success rate of ambiguity is increased.In this experiment,dynamic relative positioning data are used to analyze the number of visible satellites in GPS single sys-tem and BDS/GPS combined system,positioning accuracy in ENU direction,baseline vector difference in ENU direction,and the fixed rate of ambiguity before and after DEM con-straint.Results show that the positioning accuracy of BDS/GPS motion-to-motion relative positioning method based on DEM elevation constraint can reach centimeter level,the max-imum deviation of horizontal direction decreases from 2.73 cm to 1.45 cm,and the maximum deviation of elevation direc-tion decreases from 6.67 cm to 2.14 cm.For the experimen-tal section and the three tree-shaded sections with different shading degrees,the fixed rate of ambiguity is increased by 34.57%,27.14%,90.00%and 50.00%respectively,which can solve the position of the moving carrier more accu-rately and stably.
NETL
NSTL
万方数据
