几种附电离层约束GNSS单频PPP性能评估  

Performance evaluation of GNSS ionospheric constraint single-frequency PPP

作　　者：李众 葛海波 卜宇航 LI Zhong;GE Haibo;BU Yuhang(College of Surveying and Geo-Informatics,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学测绘与地理信息学院,上海200092

出　　处：《全球定位系统》2021年第4期59-65,共7页Gnss World of China

摘　　要：针对单频精密单点定位(PPP)两种常用的定位模型:非组合模型和附加电离层约束模型,同时综合考虑电离层约束模型三种不同约束策略(常数约束,时空约束,逐步松弛),对比分析了其使用GPS单系统及GPS+BDS双系统观测值的定位收敛时间,定位精度及其优缺点.实验结果表明:使用GPS单系统,附加不同电离层约束对单频PPP收敛时间缩短效果显著,其中逐步松弛约束平均收敛时间最短,其平均收敛时间为32.36 min,四种定位模型收敛后的定位精度基本相当.加入北斗卫星导航系统(BDS)后,四种定位模型的收敛时间均有不同程度的缩短,其中时空约束模型缩短最为显著,收敛时间缩短为单系统的59.22%.在定位精度方面,加入BDS观测值后水平方向定位精度可提升0.5~1.3 cm,垂直方向定位精度略有下降.In allusion to two commonly used models in single frequency precise point positioning(SFPPP):SF-PPP with raw and uncombined observations(SF-UC-PPP)and SF-UC-PPP with the constraint of ionospheric delay,considering simultaneously the three different ionospheric delay constraint strategies including constant,step wise relaxed and spatial-temporal strategy,these models are compared and analyzed in positioning accuracy and convergence time using GPS and GPS+BDS data.The experiment result shows that by using the GPS system observations these three models with ionospheric delay constraint can significantly improve the convergence speed of PPP,the step wise relaxed model is the fastest.Its average convergence time is 32.36 min.Accuracy of these four models after convergence is roughly equivalent.By adding the BDS data,the convergence time of these models increases differently.The spatial-temporal model has the most significant improvement,which convergence time is shorted to 59.22%of single system.Aafter the using of BDS data,the accuracy of horizontal direction is improved by 0.5 cm to 1.3 cm,the vertical accuracy has slight decrease.

关 键 词：单频精密单点定位(PPP) 定位模型 收敛时间 定位精度 多系统 

分 类 号：P228.1[天文地球—大地测量学与测量工程]