Analysis and Assessment of BDS-3 Five Single-Frequency Civilian Signals Single Point Positioning Considering Time Group Delay and Intersignal Correction

Abstract

The BeiDou Global Navigation Satellite System (BDS-3) has been providing global positioning, navigation, and timing (PNT) services for over 3 years. Single-frequency single point positioning (SPP) receivers have significant advantages such as low hardware cost and easy implementation, making them widely used in engineering practice. The time group delay (TGD) and intersignal correction (ISC) are the main parameters for single-frequency SPP and must be corrected. On-orbit 30 BDS-3 satellites have upgraded and maintained operation in 2022, while more multi-GNSS experiment (MGEX) stations can simultaneously receive all five frequency civilian signals of BDS-3, namely, B1I, B1C, B2a, B2b, and B3I. So now, it is worth assessing the SPP of BDS-3 five single-frequency civilian signals considering TGD and ISC corrections, respectively. Then, with 7 days of 73 MGEX stations simultaneously receiving all BDS-3 five frequencies, GPS L1 and Galileo E1 civilian signals were selected, and the root mean square (RMS) error was used to assess the SPP performance. The BDS-3 single-frequency SPP static and kinematic results show that the order of accuracy from high to low is B1C, B1I, B3I, B2b, and B2a. More thorough static results reveal that B1C’s RMS errors in the north, east, and up (NEU) three directions are 1.12, 0.41, and 1.78 m, respectively, and B1C outperforms B2a by 0.85, 0.28, and 1.23 m. More detailed kinematic results reveal that B1C’s NEU RMS errors are 1.47, 0.77, and 2.72 m, respectively, and that B1C outperforms B2a by 1.04, 0.47, and 1.78 m. The single-frequency SPP has a higher positioning accuracy at mid to high latitudes in the northern hemisphere than at mid to low latitudes in the southern. The single-frequency SPP of BDS-3 B1I is competitive with GPS L1 and Galileo E1. BDS-3’s five single-frequency signals, GPS L1, and Galileo E1 all perform well in the east direction, while the up direction performs badly in static and kinematic modes.