Integrity monitoring of fixed ambiguity Precise Point Positioning (PPP) solutions

Abstract

Traditional positioning methods, such as conventional Real Time Kinematic (cRTK) rely upon local reference networks to enable users to achieve high-accuracy positioning. The need for such relatively dense networks has significant cost implications. Precise Point Positioning (PPP) on the other hand is a positioning method capable of centimeter-level positioning without the need for such local networks, hence providing significant cost benefits especially in remote areas. This paper presents the state-of-the-art PPP method using both GPS and GLONASS measurements to estimate the float position solution before attempting to resolve GPS integer ambiguities. Integrity monitoring is carried out using the Imperial College Carrier-phase Receiver Autonomous Integrity Monitoring method. A new method to detect and exclude GPS base-satellite failures is developed. A base-satellite is a satellite whose measurements are differenced from other satellite's measurements when using between-satellite-differenced measurements to estimate position. The failure detection and exclusion methods are tested using static GNSS data recorded by International GNSS Service stations both in static and dynamic processing modes. The results show that failure detection can be achieved in all cases tested and failure exclusion can be achieved for static cases. In the kinematic processing cases, failure exclusion is more difficult because the higher noise in the measurement residuals increases the difficulty to distinguish between failures associated with the base-satellite and other satellites.

Long-period surface motion of the multipatch Mw9.0 Tohoku-Oki earthquake

“…However, the studies listed above did not make use of real-time or near real-time data processing strategies. Precise Point Positioning (PPP) allows to monitor the motion of standalone GPS sites (Blewitt, 2008;Ge et al, 2008;Jokinen et al, 2013). GPS, which is accurate up to a few millimetres for highfrequency oscillations in differential mode Psimoulis and Stiros, 2012), is accurate at the centimetre level in PPP mode (Moschas et al, 2014), accuracy which is sufficient to determine the surface displacement ( Figure 1) following large events (Mw > 7.0).…”

Vulnerabilities and integrity of precise point positioning for intelligent transport systems: overview and analysis

“…the probability of false alert is not specified) (see Appendix-Example 1). Jokinen et al (2011Jokinen et al ( , 2013 and Seepersad and Bisnath (2013) adopted the traditional RAIM algorithms in PPP processing to enable FDE and PL computation. They directly performed snapshot RAIM at each separate epoch even though Kalman filters were used.…”

Detection of ground motions using high-rate GPS time-series

“…Until now, however, the potential of GNSS process in real-time using the Precise Point Positioning (PPP) mode (Ge et al, 2008;Jokinen et al, 2013) complements already existing earthquake early-warning system based on seismic data only (Blewitt et al, 2009;Crowell et al, 2009;Geng et al, 2013a;Plag et al, 2012). It has been demonstrated that a warning could have been issued ~20 sec after the seismic network detection, proving the potential of GPS in that field (Allen and Ziv., 2011;Colombelli et al, 2013).…”