Atomic Clock Performance Assessment of BeiDou-3 Basic System with the Noise Analysis of Orbit Determination and Time Synchronization

Abstract

The basic system of the BeiDou global navigation satellite system (BDS-3) with 18 satellites has been deployed since December 2018. As the primary frequency standard, BDS-3 satellites include two clock types with the passive hydrogen maser (PHM) and the rubidium atomic frequency standard (RAFS). Based on the final precise orbit and clock product from Xi’an Research Institute of Surveying and Mapping (XRS), the atomic clock performance of BDS-3 satellites is evaluated, including the frequency accuracy, frequency drift rate, and frequency stability, and compared with GPS block IIF satellites with RAFS, Galileo satellites with PHM, and BDS-2 satellites. A data auto-editing procedure to preprocess clock data and assess the clock performance is developed, where the assessed results are derived at each continuous data arc and the outliers are excluded properly. The stability of XRS product noise is given by using some stations equipped with high-precision active hydrogen masers (AHM). The best stability is 8.93 × 10−15 and 1.85 × 10−15 for the averaging time of 10,000 s and 1 day, which is basically comparable to one-third of the in-orbit PHM frequency stability. The assessed results show the average frequency accuracy and drift rate of BDS-3 with RAFS are slightly worse while the stability is better than BDS-2 medium earth orbit (MEO) satellites. The 10,000 s stability is better but the 1-day stability is worse than GPS, which may be related to the performance of the BDS-3 RAFS clock. As for BDS-3 with PHM, the frequency accuracy is slightly worse than Galileo PHM satellites; the drift rate, when excluding C34 and C35, is basically comparable to Galileo and significantly better than GPS satellites; the stability is comparable to Galileo, where the 10,000 s stability is slightly worse than Galileo and better than GPS. The 1-day stability among BDS-3 PHM, GPS IIF RAFS, and Galileo PHM satellites is basically comparable.

Uncombined precise orbit and clock determination of GPS and BDS-3

“…Similarly, the C35-C37 clock accuracy is poor because of the small number of visible stations. The C25-C30, C34, and C35 satellites carry passive hydrogen atomic clocks, whereas the remaining satellites carry rubidium atomic clocks (Jia et al 2019). The clock STD difference between the two clock types is not evident.…”

“…BDS-3 was announced to serve global users on December 27, 2018 (Yang et al 2019). Many scholars have evaluated the performance of BDS-3, including signal quality (Xu et al 2019;Zhang et al 2019;He et al 2020), realtime kinematics (Zhang et al 2019), precise point positioning (Zhang et al 2019), POD (Yan et al 2019;Zeng et al 2019a), and clock performance (Jia et al 2019). Li et al (2019) showed that there is no evident systematic bias between BDS-2 and BDS-3.…”

Evaluation of Network RTK Positioning Performance Based on BDS-3 New Signal System

“…Since the end of 2018, the BDS-3 system has provided global service. A large number of scholars have studied the PNT service performance of BDS-3, and literature [4][5][6] has evaluated the signal quality of BDS-3. In the literature [7,8], the precise orbital determination of the BDS-3 satellite was studied.…”

“…Literature [14] initially evaluated the positioning performance of single-frequency and dual-frequency BDS-3 RTK based on an ultra-short baseline, pointing out that the poor signal quality of B2a frequency of BDS- Since the end of 2018, the BDS-3 system has provided global service. A large number of scholars have studied the PNT service performance of BDS-3, and literature [4][5][6] has evaluated the signal quality of BDS-3. In the literature [7,8], the precise orbital determination of the BDS-3 satellite was studied.…”

Characteristics of Onefold Clocks of GPS, Galileo, BeiDou and GLONASS Systems

“…The quality of GNSS performance depends heavily on satellite clocks [ 3 , 4 ]. In recent years, there have been a number of publications containing clock stability analyses, but the majority of them cover only one or two GNSS systems [ 5 , 6 , 7 , 8 ]. Wang et al [ 9 ] analyzed BDS clocks with the use of Allan deviation, and similar research was conducted by Steigenberger [ 10 ], but using Galileo clocks.…”