Abstract
With the advent of new Global Navigation Satellite Systems (GNSSs), multi-system, multi-frequency precise real-time kinematic (RTK) positioning can potentially be possible anywhere, at any time. The satellite constellations include the European Galileo and the Chinese BeiDou Navigation Satellite System (BDS), the regional constellation of Japan’s
Quasi-Zenith Satellite System (QZSS) and the modernized American Global Positioning System (GPS). Preliminary positioning results when combining satellites from these CDMA systems have been obtained in Australia. However, the multi-GNSS positioning performance in New Zealand has not yet been investigated. This study aims to give an initial overview of the single-baseline RTK positioning performance achievable in the South Island of New Zealand, a region with a good visibility of all these constellations.
Comparisons will be made to the positioning performance obtained in Australia that has a better visibility of the Asia-Pacific regional systems. The between-receiver differential code and phase inter-system biases (ISBs) on the overlapping frequencies will be analysed and used as a-priori corrections on independent baselines, in order to maximize the redundancy of the multi-GNSS RTK functional models. It will be shown that if the ISBs are neglected there can be a serious effect on the ambiguity resolution performance and thus the precision and reliability of the positioning results. It will also be illustrated that by combining all four-systems the RTK positioning results will be significantly improved when compared to using GPS as a stand-alone system, which has the potential to further advance applications which require high precision positioning for GNSS users in New Zealand.