Characteristics of BDS Signal-in-Space User Ranging Errors and Their Effect on Advanced Receiver Autonomous Integrity Monitoring Performance

Abstract

Signal-In-Space User Range Errors (SIS UREs) are assumed to be overbounded by a normal distribution with a standard deviation represented by the User Range Accuracy (URA). The BeiDou Navigation Satellite System (BDS) broadcast URA is not compatible with the historical SIS URE performance that affects the Advanced Receiver Autonomous Integrity Monitoring (ARAIM) False Alert Probability (Pfa) and availability evaluation. This study compares the BDS broadcast and precise ephemeris from 1 March 2013 to 1 March 2017 to obtain SIS UREs. Through analyzing the statistical characteristics of the SIS UREs, we obtain the standard deviation σURE for the accuracy and continuity and σURA used for the integrity of the SIS UREs. The results show that the broadcast σURA of 2 m cannot completely overbound SIS UREs for all BDS satellites, but the σURA of 2.4 m can. Then, we use the σURA of 2.4 m to evaluate the ARAIM Pfa and availability. The results show that the Pfa may increase to 2 × 10−5 and exceed its limit by an order of magnitude. We also consider the differences between the SIS UREs of Geostationary Earth Orbit (GEO), Inclined Geo-Synchronous Orbit (IGSO), and Medium Earth Orbit (MEO). The results indicate that all Pfa values calculated by the computed σURE are less than the Pfa in the Integrity Support Message (ISM) for the worst-performing GEO satellite. The approximately 55% Pfa calculated by the computed σURE is less than the Pfa in ISM for the worst-performing IGSO satellite. Most Pfa values calculated by the computed σURE is less than the Pfa in the ISM for the worst-performing MEO satellite. For BDS satellites, the Pfa is mainly affected by σURE. When the σURA of 2.4 m is used to evaluate the availability, the computed availability is lower than the availability calculated by the broadcast σURA/σURE and the greatest degradation can reach 25%.

A Subset-Reduced Method for FDE ARAIM of Tightly-Coupled GNSS/INS

“…The standard deviation model used here is defined in [8]. In addition, the user range accuracy (URA) [39,40] for integrity is the same as that in the broadcast ephemeris of GPS, 2.4 m.…”

Characterizing BDS signal‐in‐space performance from integrity perspective

“…This study was extended to analyze the data in 2017, where additional constellation‐specific SISRE evaluation criteria were addressed (Montenbruck, Steigenberger, & Hauschild, 2018). As for BDS‐2, some studies have investigated its nominal SIS behaviors (Wang, Shao, Li, Song, & Li, 2018; Wu et al., 2017) and its SIS anomalies (Ouyang et al., 2019). To the best of our knowledge, few studies have focused on characterizing the SISREs of BDS‐3 from the integrity perspective, although there were some preliminary assessments on its SIS accuracy (Lv, Geng, Zhao, Xie, & Zhou, 2020; Montenbruck, Steigenberger, & Hauschild, 2020).…”

A broadcast ephemeris design of LEO navigation augmentation satellites based on the integration-type ephemeris model

“…The quality of the broadcast ephemeris is mainly affected in terms of model fit errors, orbit determination precision and propagation errors [22]. The quality of broadcast ephemeris has been assessed in various studies [23][24][25][26][27]. The orbit-only contribution to the user range error (URE) in 2014 was about 0.24, 0.54, 0.76, 0.50 and 0.57 m for GPS, GLONASS, Galileo, QZSS, Beidou IGSO and MEO satellites, respectively [23].…”