International Global Navigation Satellite Systems Association
IGNSS Conference 2016
Colombo Theatres, Kensington Campus, UNSW Australia
6 – 8 December 2016
Local augmentation to wide area PPP systems: a
case study in Victoria, Australia
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
Luis Elneser
Position Partners Pty. Ltd., Australia
Phone: +61 3 9708 9900 Email: LElneser@positionpartners.com.au
Satoshi Kogure
Space Technology Directorate, Japan Aerospace Exploration Agency, Japan
Phone: +81 50 3362 3558 Email: kogure.satoshi@jaxa.jp
ABSTRACT
Precise GNSS positioning services and infrastructure are becoming
increasingly important to support precise positioning applications for
machine control in mining, civil construction, agriculture, and transport.
Currently these applications are serviced by Real-time Kinematic (RTK)
services relying on dense GNSS tracking networks. These services are
impractical to deploy over wide areas or for applications in remote areas
such as hydrographic surveying. Precise Point Positioning (PPP) have
demonstrated potential to deliver centimetre-level accuracy without the
onerous requirement of ground GNSS network. However PPP requires
solution convergence times in the order of tens of minutes compared to the
few seconds with RTK. A wide area (national or regional level) GNSS
positioning infrastructure should consist of a sparse wide area reference
network for PPP and complemented by dense local networks supporting
RTK-like systems where practical. The wide area infrastructure is used for
computation of precise satellite orbits, clocks and signal biases while the
local network is used to derive atmospheric corrections required for rapid
convergence. This paper presents the results this type of PPP-RTK system
which uses existing global correction streams, i.e., JAXA's MADOCA and
CNES's CLK91, and local ionospheric corrections derived from these
streams using Victoria's GPSnet network stations. Observables from
individual stations and the global corrections were used to estimate
tropospheric and ionospheric delays. The computed ionospheric delays were
then used to generate local ionospheric correction maps for each GPS
satellite. Real-time tests using GPS and GLONASS satellites were
performed at 5 GPSnet CORS stations. Results show that PPP-RTK type
system using local ionospheric corrections can significantly reduce the
solution convergence times and positioning errors in PPP
KEYWORDS: Precise Point Positioning (PPP); Rapid convergence;
ionospheric corrections;
