Article
Design and Performance Analysis of BDS-3 Integrity Concept
Cheng Liu
1
, Yueling Cao
2
, Gong Zhang
3
, Weiguang Gao
1,
*, Ying Chen
1
, Jun Lu
1
, Chonghua Liu
4
, Haitao Zhao
4
and Fang Li
5
Citation: Liu, C.; Cao, Y.; Zhang, G.;
Gao, W.; Chen, Y.; Lu, J.; Liu, C.; Zhao,
H.; Li, F. Design and Performance
Analysis of BDS-3 Integrity Concept.
Remote Sens. 2021, 13, 2860. https://
doi.org/10.3390/rs13152860
Academic Editor: Kamil Krasuski
Received: 15 June 2021
Accepted: 19 July 2021
Published: 21 July 2021
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4.0/).
1
Beijing Institute of Tracking and Telecommunication Technology, Beijing 100094, China;
liucheng@beidou.gov.cn (C.L.); cheny@beidou.gov.cn (Y.C.); lujun@beidou.gov.cn (J.L.)
2
Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China;
caoyueling@shao.ac.cn
3
Institute of Telecommunication and Navigation, CAST, Beijing 100094, China; zhanggong@cast.casc
4
Beijing Institute of Spacecraft System Engineering, Beijing 100094, China; liuchonghua@cast.casc (C.L.);
zhaohaitao@cast.casc (H.Z.)
5
National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100094, China; lifang@bao.ac.cn
* Correspondence: gaowg@beidou.gov.cn
Abstract:
Compared to the BeiDou regional navigation satellite system (BDS-2), the BeiDou global
navigation satellite system (BDS-3) carried out a brand new integrity concept design and construction
work, which defines and achieves the integrity functions for major civil open services (OS) signals
such as B1C, B2a, and B1I. The integrity definition and calculation method of BDS-3 are introduced.
The fault tree model for satellite signal-in-space (SIS) is used, to decompose and obtain the integrity
risk bottom events. In response to the weakness in the space and ground segments of the system, a
variety of integrity monitoring measures have been taken. On this basis, the design values for the
new B1C/B2a signal and the original B1I signal are proposed, which are 0.9
×
10
−5
and
0.8 × 10
−5
,
respectively. The hybrid alarming mechanism of BDS-3, which has both the ground alarming
approach and the satellite alarming approach, is explained. At last, an integrity risk analysis and
verification work were carried out using the operating data of the system in 2019. The results show
that the actual operation of the system is consistent with the conceptual design, which satisfies the
integrity performance promised by BDS-3 in the ICAO SAPRs.
Keywords:
BDS; BeiDou; integrity; risk tree; FMEA; satellite service failure; constellation service
failure
1. Introduction
Accuracy, integrity, continuity, and availability are the four core performance indi-
cators of satellite navigation systems. Among them, integrity refers to the ability of the
system to alert users in time when the service is abnormal or experiences failure, and it
characterizes the security and reliability of system services [
1
,
2
]. If there is an abnormality
or failure in the service, but the system fails to detect it or fails to alarm in time, an “integrity
event” has occurred. Once an integrity event occurs, it will have a security impact on
the user, especially for civil aviation, maritime, railway, and other users related to life
safety. System reliability is even more strategically important with the widespread use of
low-cost sensors for various applications including personal positioning and autonomous
navigation [
3
,
4
]. In addition, the integrity of the core constellation is also an important
foundation for the construction of the satellite-based augmentation systems (SBAS) such as
WASS (wide area augmentation system) [
5
,
6
], ENGOS (European geostationary naviga-
tion overlay system) [
7
,
8
], MSAS (multi-functional satellite augmentation system) [
9
,
10
],
BDSBAS (BeiDou satellite-based augmentation system) [
11
], and airport ground-based
augmentation systems (GBAS). These augmentation systems are constructed to further
augment the global navigation satellite system (GNSS) constellation and provide higher
integrity navigation services.
Remote Sens. 2021, 13, 2860. https://doi.org/10.3390/rs13152860 https://www.mdpi.com/journal/remotesensing
