北斗格网电离层模型格网点计算方法研究

The research of IGP algorithms for grid ionospheric model correction in BDS

基于北斗导航系统星基增强系统的格网电离层模型修正算法,讨论了由穿透点处的垂直延迟计算格网点处垂直电离层延迟的计算方案,并检验了格网电离层垂直延迟修正误差GIVE。结果表明,格网电离层修正算法是一种精度较高的电离层延迟修正法,选取格网点附近参考站的可用数据计算出的格网点垂直延迟值更接近真实延迟值,进而有利于获得高精度的电离层改正效果,证明了电离层格网点的延迟值是建立格网模型的关键;修正误差在正常范围内,验证了算法在中国地区的可行性,也说明了GIVE算法能够以99.9%的置信度限定格网点电离层延迟改正误差。

Based on the grid ionospheric correction algorithm of BDSBAS,the paper discusses how to calculate the IGP vertical ionospheric delay by the IPP vertical ionospheric and tests the grid point ionospheric vertical delay error （GIVE）.The results show that grid ionospheric model is a kind of high accuracy ionospheric delay correction algorithm and the delay of ionospheric grid is the key of the grid model;selects near the IGP reference station to calculate the vertical grid delay is more accurate and is also beneficial to obtain high-accuracy ionospheric correction effect;Additionally,the correction error is in a normal range,verifies the algorithm of GIVE is workable in the area of China and can limit the grid point ionospheric delay error with a confidence level of 99.9%.