Modelling and assessment of Galileo and Galileo/GPS velocity determination with stand-alone receiver

Abstract

Reasonable stochastic model and function model are the premise of accurate velocity determination, especially in the time-differenced carrier-phase (TDCP) method. This paper presents, first, an elevation-dependent stochastic model (ESM), and then gives a simplified and unified Galileo/GPS combined TDCP function model, where the inter-system bias (ISB) variations are analysed based on correlation coefficients and the scaled sensitivity matrix. To evaluate the performance of the proposed models, datasets collected at 10 multi-GNSS experiment (MGEX) stations and a vehicle kinematic experiment are employed. The results indicate that the ESM model can improve the accuracy of the velocity solution, especially for the Galileo/GPS combined system, in comparison with the equivalent weight ratio method. In contrast to the Galileo-only velocity solution, the Galileo/GPS combined velocity solution can bring improvements of about 1–1⋅5 mm/s, 0⋅5 mm/s and 1⋅5–2⋅5 mm/s in East, North and Up components, respectively. Compared with the traditional Galileo/GPS TDCP model, the simplified and unified model shows no obvious differences in all components in the environment with more visible satellites, but it performs better in a challenging environment with few visible satellites.

Assessing Potential Performance of GPS and Galileo in context of Broadcast Precise Orbits and Clock Corrections

“…Some researchers are analysing Galileo's absolute positioning performance in navigation [2,3]. With ample research demonstrating the benefits of Galileo in multi-GNSS environments in various geographical regions [4][5][6][7][8], there has been a lack of study to demonstrate the performance of Galileo in India, especially with mass-market GNSS receivers. However, very little research on Galileo's performance evaluation over India has been reported [9].…”