Precise Point Positioning using Triple-Frequency GPS Measurements

Abstract

Precise Point Positioning (PPP) performance is improving under the ongoing Global Positioning System (GPS) modernisation program. The availability of the third frequency, L5, enables triple-frequency combinations. However, to utilise the modernised L5 signal along with the existing GPS signals, P1-C5 differential code bias must be determined. In this paper, the global network of Multi-Global Navigation Satellite System Experiment (MGEX) stations was used to estimate P1-C5 satellites differential code biases ðDCB S P1ÀC5 Þ. Mathematical background for triple-frequency linear combinations was provided along with the resultant noise and ionosphere amplification factors. Nine triple-frequency linear combinations were chosen, based on different criteria, for processing the modernised L5 signal along with the legacy GPS signals. Finally, test results using real GPS data from ten MGEX stations were provided showing the benefits of the availability of the third frequency on PPP solution convergence time and the precision of the estimated parameters. It was shown that triple-frequency combinations could improve the PPP convergence time and the precision of the estimated parameters by about 10%. These results are considered promising for using the modernised GPS signals for precise positioning applications especially when the fully modernised GPS constellation is available. K E Y WO R D S 1. Precise Point Positioning.2. GPS Modernisation. 3. Hardware Delay.

Performance of real-time Precise Point Positioning using IGS real-time service

“…The observations are processed in both static and kinematic modes using the PPP software developed by the first author (Elsobeiey 2015;Elsobeiey and El-Rabbany 2014). The input is the first-order ionospheric-free code and carrier phase (8) and (9).…”

Precision and Reliability of Tightly Coupled PPP GNSS and Landmark Monocular Vision Positioning

“…Precise Point Positioning (PPP) is a positioning technique which utilizes un-differenced pseudorange and carrier phase measurements with the aid of GNSS data products from a global network of reference stations providing precise satellite orbits and clocks [3][4][5]. We use single-frequency PPP [6].…”

Performance Analysis of Atmospheric Constrained Uncombined Multi-GNSS PPP

“…However, PPP implementation has changed from the usage of dual-frequency measurements to a triple-frequency approach (Hofmann-Wellenhof et al 2007;Jan 2010;Schönemann et al 2011;Fairhurst et al 2001). Opportunities and challenges are both presented with modernized GPS, GLONASS, Galileo and BeiDou constellations when solution accuracy, reliability and integrity become the focus (Henkel and Günther 2010;Elsobeiey 2014). Some prominent areas demanding attention in the quest to enhance PPP performance are convergence and initialization Bisnath 2012, 2014a, b).…”

“…The uncombined PPP approach implies the estimation of ionospheric delay parameters which can further be strengthened through a priori ionospheric knowledge (Collins et al 2012;Banville et al 2014;Laurichesse and Blot 2016). The extra widelane provided by third frequency measurements aid in achieving the goal of faster initial PPP solution convergence (Geng and Bock 2013;Li et al 2013;Tang et al 2014;Elsobeiey 2014;Laurichesse and Blot 2016;Gayatri et al 2016).…”