GPS Solutions ( IF 4.9 ) Pub Date : 2021-03-01 , DOI: 10.1007/s10291-021-01102-5 Ke Su , Shuanggen Jin , J. Jiang , Mainul Hoque , Liangliang Yuan
The ionospheric delays and satellite differential code biases (DCBs) act as the significant error sources in the global navigation satellite system (GNSS) positioning, navigation and timing (PNT) services, and are still challenging to estimate correctly. In this study, the ionospheric vertical total electron content (VTEC) and satellite DCBs are estimated by a refining single-frequency precise point positioning (SFPPP) method based on the multi-layer ionosphere mapping function (MF), as well as the dual-frequency methods, including the carrier-to-code leveling (CCL) and dual-frequency PPP (DFPPP). The solutions isolate the ionospheric VTEC values from the slant ionospheric delay with the generalized trigonometric series function (GTSF) and precisely estimate the satellite DCB with a zero-mean condition. The SFPPP-derived VTEC estimates are validated and evaluated by comparing with the International GNSS Service (IGS) products and using ionosphere-corrected (IC) SFPPP in both static and kinematic scenarios. Using the 74 experimental stations collected from the multi-GNSS experiment (MGEX) network from January to March 2020, the results show that the VTEC estimation precision by applying the multi-layer MF is improved for the SFPPP approach. The positioning performances of the static and kinematic BDS IC SFPPP with the ionospheric correction derived from the multi-layer MF SFPPP are better when compared to the single-layer MF. The estimated BDS DCB with the SFPPP is stable and of high accuracy. The SFPPP approach with multi-layer MF is demonstrated as a promising and reliable method to retrieve the VTEC and satellite DCB with the low-cost property for the GNSS users.
中文翻译:
从具有多层映射功能的单频BDS观测值估计电离层VTEC和卫星DCB
电离层延迟和卫星差分代码偏差(DCB)是全球导航卫星系统(GNSS)定位,导航和授时(PNT)服务中的重要误差源,并且仍然难以正确估算。在这项研究中,电离层垂直总电子含量(VTEC)和卫星DCB是通过基于多层电离层映射函数(MF)以及双电层的双频精制单频精确点定位(SFPPP)方法估算的频率方法,包括载波至代码均衡(CCL)和双频PPP(DFPPP)。这些解决方案利用广义三角函数(GTSF)将电离层VTEC值与倾斜的电离层延迟隔离开,并精确地以零均值条件估算卫星DCB。通过与国际GNSS服务(IGS)产品进行比较并在静态和运动学情况下使用电离层校正(IC)SFPPP,对SFPPP得出的VTEC估算值进行了验证和评估。使用从2020年1月至2020年3月从多GNSS实验(MGEX)网络收集的74个实验站,结果表明,对于SFPPP方法,通过应用多层MF可以提高VTEC估算精度。与多层MF相比,通过多层MF SFPPP进行电离层校正的静态和动态BDS IC SFPPP的定位性能更好。使用SFPPP估算的BDS DCB是稳定的,并且具有很高的精度。