International Global Navigation Satellite Systems Association
IGNSS Conference 2016
Colombo Theatres, Kensington Campus, UNSW Australia
6 – 8 December 2016
Performance of Precise Point Positioning using
Current Triple-frequency GPS Measurements in
Australia
Viet Duong
School of Science, RMIT University, Australia
Phone: +61 4 1340 1871 Email: viet.duong@rmit.edu.au
Ken Harima
School of Science, RMIT University, Australia
Phone: +61 3 9925 3775 Email: ken.harima@rmit.edu.au
Suelynn Choy
School of Science, RMIT University, Australia
Phone: +61 3 9925 2650 Email: suelynn.choy@rmit.edu.au
Chris Rizos
School of Civil and Environmental Engineering, University of New South Wales, Australia
Phone: +61 2 9385 4205 Fax: +61 2 9385 6139 Email: c.rizos@unsw.edu.au
ABSTRACT
GNSS Network Real-Time-Kinematic (NRTK) has become a common
service for many precise positioning applications over the last two decades.
However, NRTK cannot service or support user applications if they are
outside the Continuously Operating Reference Stations (CORS) network
coverage area, such as in the case of offshore surveying. In addition, NRTK
requires a fairly dense network of CORS (typically station separation <80
km) to generate reliable corrections for centimetre-level positioning, and
ground communication channels to disseminate the corrections to users.
Precise Point Positioning (PPP) is a viable alternative for some GNSS
applications as it does not have the onerous requirement of a dense network
of CORS infrastructure. However the current major limitation of the PPP
technique is the slow solution convergence time (tens of minutes for the
solutions to converge to decimetre-level accuracy). This is not adequate to
support many real-time positioning and navigation applications requiring
high accuracy positioning. This paper describes the prospects, effectiveness
as well as challenges in using triple-frequency GPS measurements in a PPP
model. In particular, the paper describes research into assessing the
performance of triple-frequency PPP. One week of triple-frequency GPS
observations from eight CORS stations in Australia were processed in static
mode. The estimated positions were then compared with the known
coordinates. The results indicate that the use of triple-frequency GPS
measurements improves the 3D positioning accuracies as well as shortens
solution convergence times compared to dual-frequency PPP.
