343
1 INTRODUCTION
With satellite navigation as an enabling technology
for a growing number of applications, maintaining
Global Navigation Satellite Systems’ (GNSS)
Positioning, Navigation, and Timing (PNT) service
has become a necessity. Different GNSS applications
require appropriate quality of PNT (GSA, 2018).
Studies of GNSS positioning performance in different
scenarios of applications thus add to the knowledge
base that empowers risk assessment of GNSS
utilisation (HM Government Office for Science, 2018).
Tropospheric delay of GNSS signal is caused by its
propagation through non-ionised but non-homogenic
medium just above the Earth’s surface (Hopfield,
1972), (Parkinson, Spilker, Jr., 1996), (Teunissen,
Montentbruck, 2017), (Reguzzoni, 2013), (Schueller,
2001). Meteorological parameters, such as air
temperature, air pressure, and water vapour partial
pressure, determines the delay encountered by
satellite signal while propagating through
troposphere (Parkinson, Spilker, Jr., 1996), (Teunissen,
Montentbruck, 2017), (Schueller, 2001). The GNSS
tropospheric delay consists of a dry-air and a wet-air
components, with the latter particularly enlarged
during weather deterioration (Parkinson, Spilker, Jr.,
1996), (Teunissen, Montentbruck, 2017), (Zhou et al,
2017). Tropospheric delay of GNSS signal is then
mapped onto GNSS positioning error using the
geometry matrix (Filić, and Filjar, 2018).
Here we analysed the dynamics of GPS
positioning error due to tropospheric delay for a
selected case of tropical cyclone Marcus (Figure 1)
that stroke the city of Darwin, Australia in 2018, a
devastating tropical cyclone in a coastal region,
affecting a range of maritime GNSS applications
(BOM, 2018). The aim of research was to study GPS
positioning error variations due to tropospheric delay,
Analysis of Tropospheric Contribution to GPS
Positioning Error During Tro
pospheric Cyclone Marcus
in 2018
N
. Sikirica
Krapina University of Applied Sciences, Krapina, Croatia
M
. Horvat
Zagreb University of Applied S
ciences, Zagreb, Croatia
D
. Špoljar & I. Rumora
University of Rijeka, Rijeka, Croatia
ABSTRACT: GNSS positioning performance assessment is essential for sustainable development of a growing
number of GNSS-based technology and socio-economic applications. Case-
studies of GNSS positioning
performance in critical environments and applications scenarios reveals vulnerabilities of the GNSS
Positioning, Navigation, and Timing (PNT) services, and suggest mitigation techniques and GNSS application
risk containment. Here we address the case of GPS positioning performance during a devastating tropical
cyclone Marcus that hit the greater area of the city of Darwin, Australia in 2018. We identified specific statistical
properties of time series of tropospheric contribution to GPS northing, easting, and vertical positioning error
that may contribute to understanding of tropospheric effects on GPS positioning performance during a massive
weather deterioration in maritime and coastal areas, and analysed their adversarial effects on GNSS-based
maritime applications.
http://www.transnav.eu
the
International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 14
Number 2
June 2020
DOI:
10.12716/1001.14.02.10