Article
Pseudorange Bias Analysis and Preliminary Service
Performance Evaluation of BDSBAS
Yuchen Liu
1,2
, Yueling Cao
1,
*, Chengpan Tang
1
, Jinping Chen
3
, Liqian Zhao
4
, Shanshi Zhou
1
, Xiaogong Hu
1
,
Qiuning Tian
1,2
and Yufei Yang
3
Citation: Liu, Y.; Cao, Y.; Tang, C.;
Chen, J.; Zhao, L.; Zhou, S.; Hu, X.;
Tian, Q.; Yang, Y. Pseudorange Bias
Analysis and Preliminary Service
Performance Evaluation of BDSBAS.
Remote Sens. 2021, 13, 4815. https://
doi.org/10.3390/rs13234815
Academic Editors: Kamil Krasuski
and Prasad S. Thenkabail
Received: 2 September 2021
Accepted: 25 November 2021
Published: 27 November 2021
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4.0/).
1
Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China;
liuyuchen@shao.ac.cn (Y.L.); cptang@shao.ac.cn (C.T.); sszhou@shao.ac.cn (S.Z.); hxg@shao.ac.cn (X.H.);
tianqiuning@shao.ac.cn (Q.T.)
2
University of Chinese Academy of Sciences, Beijing 100049, China
3
Beijing Navigation Center, Beijing 100094, China; jinping_chen@sina.com (J.C.); gnssyyf@163.com (Y.Y.)
4
Space Star Technology Co., Ltd., Beijing 100095, China; zhaoliqian@shao.ac.cn
* Correspondence: caoyueling@shao.ac.cn
Abstract:
To satisfy the demands of civil aviation organizations and other users of satellite navigation
systems for high-precision and high-integrity service performance, many countries and regions have
established satellite-based augmentation systems (SBAS) referring to the Radio Technical Commission
for Aeronautics (RTCA) service standards and agreements. The BeiDou SBAS (BDSBAS) provides
both single-frequency service, which augments Global Positioning System (GPS) L1 C/A signal, and
dual-frequency multi-constellation (DFMC) service, which augments BeiDou Navigation Satellite
System (BDS) B1C and B2a dual frequency signals presently, meeting the requirements of the RTCA
DO-229D protocol and the SBAS L5 DFMC protocol requirements, respectively. As one of the main
error sources, the pseudorange bias errors of BDSBAS monitoring receivers were estimated and their
effect on the performance of the BDSBAS service was analyzed. Based on the user algorithms of SBAS
differential corrections and integrity information, the service accuracy, integrity, and availability of
the BDSBAS were evaluated using real observation data. The results show that the maximum of
monitoring receiver pseudorange bias errors between L1P and L1P/L2P can reach 1.57 m, which
become the most important errors affecting the performance of the BDSBAS service. In addition, the
results show that the pseudorange bias of GPS BlockIII is the smallest, while that of GPS BlockIIR is
the largest. Compared with the positioning accuracy of the open service of the core constellation, the
positioning accuracy of the BDSBAS service can be improved by approximately 47% and 36% for the
RTCA service and DFMC service, respectively. For RTCA services, the protection limit (PL) calculated
with the integrity information can 100% envelop the positioning error (PE) and no integrity risk event
is detected. The service availability of BDSBAS for APV-I approach is approximately 98.8%, which is
mainly affected by the availability of ionospheric grid corrections in the service marginal area. For
DFMC service, the integrity risk is not detected either. The service availability for CAT-I approach is
100%. Improving the availability of ionospheric grid corrections is one of the important factors to
improve service performance of BDSBAS RTCA service.
Keywords: BDSBAS; pseudorange bias; accuracy; integrity; availability
1. Introduction
With the continuous development and construction of satellite navigation systems,
there are currently four global navigation satellite systems (GNSS), namely: the Global
Positioning System (GPS), Global Navigation Satellite System (GLONASS), Galileo and
BeiDou Navigation Satellite System (BDS), and regional navigation satellite systems, such
as Quasi-Zenith Satellite System (QZSS) and Indian Regional Navigation Satellite System
(IRNSS) [
1
]. Satellite navigation systems are widely used in positioning, navigation, and
Remote Sens. 2021, 13, 4815. https://doi.org/10.3390/rs13234815 https://www.mdpi.com/journal/remotesensing
