International Global Navigation Satellite Systems Association
IGNSS Symposium 2018
Colombo Theatres, Kensington Campus, UNSW Australia
7 – 9 February 2018
Vulnerabilities in SBAS and RTK Positioning in
Intelligent Transport Systems: An Overview
Davide Imparato
Department of Spatial Sciences, Curtin University,
Perth, Australia
Tel: +61 8-92663403, Email: davide.imparato@curtin.edu.au
Ahmed El-Mowafy
Department of Spatial Sciences, Curtin University,
Perth, Australia
Tel: +61 8-92663403, Email: a.el-mowafy@curtin.edu.au
Chris Rizos
School of Civil and Environmental Engineering, UNSW,
Sydney, Australia
Tel: +61 2 93854205, Fax: +61 2 9385 6139, Email: c.rizos@unsw.edu.au
Jinling Wang
School of Civil and Environmental Engineering, UNSW,
Sydney, Australia
Tel: +61 2 93854203, Fax: +61 2 9385 6139, Email: jinling.wang@unsw.edu.au
ABSTRACT
As Intelligent Transport Systems (ITS) become more automated and more
demanding, ITS positioning integrity is becoming a key performance
parameter. ITS relies on GNSS technology for absolute positioning. In order
to develop efficient models and methods that can provide high levels of
integrity, it is necessary to study the vulnerabilities of the GNSS-based
positioning systems intended for use in ITS applications, in particular those
which require positioning accuracy at the sub-metre level. These
vulnerabilities are attributed to several sources and include biases and errors
in the GNSS measurements, and in the corrections applied to the
measurements for augmented performance, as well as those induced by the
operating environment. The vulnerabilities also comprise possible anomalies
that may affect each component of the system, including disturbances or
disruption in the communications between the service provider and users, data
latency, to name a few. In this paper a preliminary overview of possible
vulnerabilities is presented for two widely-used GNSS positioning techniques
envisioned for ITS applications: the Satellite-Based Augmentation System
(SBAS) and low-cost RTK. Some examples are given, including the source
of these errors, e.g. satellite or receiver hardware, environment, external
communications, the error magnitude, temporal and spatial behaviour, their
deterministic and stochastic characteristics, and their impact on estimated
positions. Furthermore, some of the corresponding mathematical models that
can be used to describe these vulnerabilities in the integrity monitoring
