GPS+BDS中长距离RTK定位算法及结果分析

GPS+BDS Medium-Long Range RTK Positioning Algorithm and Result Analysis

GPS/BDS中长距离RTK定位因为电离层和对流层残余误差的影响,其性能相对于常规RTK有所降低。将GPS/BDS卫星双差电离层误差和对流层误差作为参数,采用卡尔曼滤波进行实时估计。为了验证算法的有效性,利用武汉地区103 km静态基线24 h双频观测数据,分析了GPS和BDS单系统以及二者组合双系统中长距离RTK定位性能。实验结果表明,精确估计的双差电离层残余误差达到米级、对流层误差达到分米级;经过改正后,GPS/BDS单系统的定位精度在1 cm左右,组合双系统则实现了中长距离基线毫米级的高精度定位。

The performance of medium-long rang RTK is much degraded compared with that of conventional shortrange RTK due to the effects of residual ionospheric and tropospheric errors. In this paper, the double differenced （DD） residual ionospheric and tropospheric errors are taken as parameters to estimate using the Kalman filter. The dual-frequency data with 103 km baseline distributed in Wuhan city during 24 hours is used to validate the algorithm introduced in this paper, the medium-long RTK performances of GPS＋BDS single system and the combined system are analyzed. The experiment result shows that the estimated DD ionosphere residual error can reach the meter level, ionosphere residual error can reach the decimeter level. After the correction of them, GPS/BDS single system positioning accuracy is about 1 cm, while the combined system can accomplish the millimeter level positioning accuracy of the medium-long baseline.