First results of mixed GPS+GIOVE single-frequency RTK in Australia

Abstract

First results are presented for precise (mm/cm-level) short-baseline RTK positioning based on single-frequency GPS data combined with data of GIOVE-A/B, the two experimental Galileo satellites, collected in Australia. The paper first focuses on the model of GPS+Galileo observation equations and addresses the issues that arise when combining data of both systems, in particular the inter-system biases (ISBs). Our results indicate that the differential ISBs are quite stable in time, potentially enabling calibration and a priori correction of the Galileo phase and code observations. Based on ISB-corrected data, the reliability of single-frequency GPS+GIOVE ambiguity resolution is significantly improved, when compared to GPS only.

Keywords:

• GPS
• Galileo
• inter-system bias (ISB)
• integer ambiguity resolution
• single-frequency RTK
• calibration

Acknowledgements

This work has been executed in the framework of the Positioning Program Project 1.01 (New carrier phase processing strategies for achieving precise and reliable multi-satellite, multi-frequency GNSS/RNSS positioning in Australia) of the Cooperative Research Centre for Spatial Information (CRC-SI). Peter J.G. Teunissen is the recipient of an Australian Research Council (ARC) Federation Fellowship (project number FF0883188). All this support is gratefully acknowledged.