Analysis of the BDGIM Performance in BDS Single Point Positioning

Abstract

The broadcast ionospheric model is mainly used to correct the ionospheric delay error for single-frequency users. Since the BeiDou global ionospheric delay correction model (BDGIM) is a novel broadcast ionospheric model for BDS-3, its performance was analyzed through single point positioning (SPP) in this study. Twenty-two stations simultaneously receiving B1C, B2a, B1I and B3I signals were selected from the International GNSS Service (IGS) and the International GNSS Monitoring and Assessment System (iGMAS) tracking networks for the SPP experiments. The differential code bias (DCB) parameters were used to correct the hardware delays in the signals of B1C and B2a. The results showed that the BDGIM performs the best in high-latitude areas, and can effectively improve the positioning accuracy compared with the Klobuchar model. The average 3D positioning accuracy of the four civil signals can reach 3.58 m in high-latitude areas. The positioning accuracies with the BDGIM in the northern hemisphere are better than those in the southern hemisphere, and the global average 3D positioning accuracy of the four civil signals is 4.60 m. The performance of the BDGIM also shows some seasonal differences. The BDGIM performs better than the Klobuchar model on the days of spring equinox and winter solstice, while the opposite is true on the days of summer solstice and autumn equinox. On the day of winter solstice, the average 3D accuracies with the BDGIM on the signals of B1C, B2a, B1I and B3I are 4.13 m, 5.32 m, 4.40 m and 4.49 m, respectively. Although the SPP accuracies are to some extent affected by the geomagnetic storm, the BDGIM generally performs better and are more resistant to the geomagnetic storm than the Klobuchar model.

Ensemble Machine Learning of Random Forest, AdaBoost and XGBoost for Vertical Total Electron Content Forecasting

“…The proposed VTEC models have perspectives to be used as a useful source of information for single-frequency GNSS users to mitigate the ionospheric delay and thereby, directly reduce the ionospheric range error. For instance, the final GIM CODE improves 3D single-frequency position estimates by about 5.5 m, 1 m, and 2.5 m on average in high-, mid-, and low-latitude regions, respectively, compared to the real-time available Klobuchar model [52]. However, considering that the final GIMs are usually provided with a time delay of 1-2 weeks, and the rapid GIMs with 1-2 days [53], their application in real-time is not possible.…”

Investigation of the Contribution of Five Broadcast Ionospheric Models (GPSK, NTCMG, NEQG, BDGIM, and BDSK) and IRTG to GNSS Positioning During Different Solar Activities in Solar Cycle 25

“…One possible reason for this is the lack of publicly available RT BDGIM parameters, which are not included in standard RINEX v3.04 navigation files. Current analyses using operational BDGIM data are generally limited to periods before July 2021 (Guangxing Wang et al., 2021; Tian et al., 2022; Yasyukevich et al., 2023; Q. Zhang, Liu, Liu, et al., 2022; Zhu et al., 2019). The performance of the actual broadcast BDGIM during different solar activities in the positioning domain has not been thoroughly validated and analyzed.…”

Tropospheric Delay Parameter Estimation Strategy in BDS Precise Point Positioning

“…Atmospheric delay consists of ionospheric delay and tropospheric delay (TD) [1,2]. TD can be split into hydrostatic delay (HD) and wet delay (WD) components [3][4][5]. HD, also called dry delay, is mainly affected by atmospheric pressure and temperature, contributing to about 90% of the total delay, and is relatively stable and can be corrected precisely using tropospheric models.…”