附加区域电离层约束的PPP定位收敛性分析

Convergence Analysis of PPP Additional Regional Ionospheric Constraints

为了改善PPP的定位精度和收敛速度,提出一种有效的解决思路:在非差非组合模型PPP定位的基础上,附加高精度区域电离层先验信息约束,利用美国西海岸CORS网内183个参考站的观测数据进行区域电离层建模,获取高精度电离层延迟信息;通过实验对比分析无电离层组合模型、非差非组合模型和附加电离层约束的非差非组合模型3种算法的PPP定位表现,结果表明,附加电离层约束算法具有更好的模型几何强度,相比于前两种模型,在PPP定位过程前10 min,该算法可以显著提升PPP定位的收敛速度和定位精度。

The problem of long convergence time restricts the development of precise point positioning(PPP)technology in the application field.In order to improve the positioning accuracy and convergence speed of PPP,we propose an ionosphere-constraint model based on uncombined and unconstrained model,and the high-precision regional ionospheric a priori information constraint method.We use the observation data of 183 reference stations in the west coast CORS network of the United States to model the regional ionosphere,obtain high-precision ionospheric delay information,and compare and analyze through experiments,the PPP positioning performance of the three algorithms:ionosphere-free,uncombined and unconstrained and ionosphere-constraint model.The experimental results show that the additional ionospheric constraint algorithm has better model geometric strength.Compared with the first two models,the PPP 10 minutes before the positioning process,this algorithm can significantly improve the convergence speed and positioning accuracy of PPP positioning.