[G05-2] Single- and Multi-GNSS

[G05-2-03] Statistical Analysis of Multi-GNSS Inter-System Biases for Precise Point Positioning Ambiguity Resolution

Shuyang Cheng, ^○Jinling Wang (School of Civil and Environmental Engineering, UNSW Sydney, Australia)

Compatibility and interoperability among multi-GNSS constellations are the necessity for reliable multi-GNSS positioning and navigation, thus, attracting great attention from the satellite navigation community over recent years. There are inter-system biases affecting precise point positioning (PPP) ambiguity resolution. While it has been well known that differenced integer ambiguities between satellites are resolvable. in the current PPP ambiguity resolution procedures, due to the multi-GNSS Inter-System Biases, the integer carrier phase ambiguities between satellites within a single constellation are formed, for example, GPS ambiguities and Galileo ambiguities are separate. Such a situation will certainly reduce the performance of multi-GNSS ambiguity resolution due to a relatively weaker geometry than the scenario in which integer ambiguities between any satellites within multi-constellations can be resolved.

In this paper, we will investigate the statistical characteristics of multi-GNSS Inter-System Biases, especially in the carrier phase domain, and design procedures to estimate and accommodate these biases towards the goal to resolve the integer ambiguities between any satellites within the multi-constellation GNSS. For example, in conventional PPP-AR methods, one GPS and one Galileo satellites are chosen as reference satellites to form inner-system between-satellite-single-differencing (BSSD). In this new method, only one GPS satellite will be selected as the pivot satellite to form GPS-GPS inner-system BSSD and GPS-Galileo inter-system BSSD. Experimental results will be presented to show the time variability of these ISBs and compare the PPP-AR performance of this new method and traditional methods.