两种电离层模型对卫星导航定位精度的影响分析

Comparative Analysis of BDS and GPS Ionospheric Model on Positioning and Navigation Precision

北斗卫星导航系统及全球定位系统等全球卫星导航系统电磁波信号在大气中传播会受到电离层延迟的影响,为满足导航用户需求,我国北斗卫星导航系统和美国全球定位系统均采用Klobuchar 8参数模型进行电离层延迟改正。但是全球定位系统Klobuchar模型和北斗卫星导航系统Klobuchar模型的电离层参数并不相同,分析不同导航系统发布的电离层参数精度对这两种双模导航定位中电离层参数的选择具有重要的研究意义。分别采用北斗卫星导航系统和全球定位系统电离层模型进行伪距单点定位,通过比较最终的定位精度从而对这两种不同模型在全球范围内的改正精度进行评价。研究结果表明:在中国区域内,采用北斗卫星导航系统模型的伪距单点定位精度较全球定位系统模型有较大提高;采用北斗卫星导航系统电离层参数更利于中国区域的全球卫星导航系统的导航定位。

While passing through the atmosphere,the global navigation satellite system(GNSS)signals from BeiDou navigation satellite system(BDS)and global positioning system(GPS)suffer the influence of ionospheric delay.To meet the positioning precision for requirements of the users,the BDS and GPS both provide the Klobuchar 8-parameter correction model for ionospheric delay.But the GPS model is based on the geomagnetic reference frame while the BDS model is based on the geography reference frame.It is significant to compare the correction precision of these two models for selecting ionospheric model parameters when navigating and positioning with combined GPS/BDS techniques.The evaluation is done in this paper by comparing and analyzing the precision of single point positioning(SPP)with GPS and BDS ionospheric model.The final result indicates that SPP with BDS ionospheric model can reach higher precision with respect to GPS model in China area.So in China area it is more appropriate to adopt the BDS ionospheric correction model.