BDS三频非差RTK单历元定位方法

Positioning method of BDS triple-frequency undifferenced RTK single-epoch

针对BDS三频RTK单历元解算基本频点模糊度成功率不高的问题,提出一种基于BDS三频观测值组合的非差RTK流动站单历元定位方法:计算参考站伪距及载波相位观测值的非差误差改正数,并根据非差改正数进行流动站点单颗卫星观测值的误差改正;然后采用无几何模型和基于几何模型单历元的方法固定流动站2个超宽巷单差模糊度,并通过线性组合得到宽巷模糊度,对基本频点求解进行约束;最后通过采用LAMBDA方法固定基本频点B1单差模糊度来进行实时动态定位。实验结果表明,实测50m超短基线和7km短基线情况下,该方法能够分别以98.93%和98.97%的成功率固定基本频点模糊度,并获得厘米级的单历元定位精度。

Aiming at the problem that it is difficult to successfully solve the basic frequency ambiguity for BDS triple-frequency RTK single-epoch,the paper proposed a single-epoch positioning method of undifferenced RTK floating station based on combined BDS triple-frequency observations:the undifferenced error correction of the pseudorange and carrier-phase observation on the reference station was calculated,and the errors of single satellite observations on the floating station were corrected based on the undifferenced correction;then two extra-widelane single differenced ambiguities of the station were fixed by the methods of geometry-free and geometry-based single-epoch,and the widthlane ambiguity was obtained with linear combination to constrain the basic frequency points;finally the basic frequency B1 single difference ambiguity was fixed by LAMBDA to do the real-time kinematic positioning.Experimental result showed that for the measured 50 m and 7 km short lines,the basic frequency ambiguity could be fixed at the successful rates of 98.93%and 98.97%,with the single-epoch positioning accuracy of centimeter level by the proposed method.