JSG T.30

JSG T.30: Multi-GNSS theory and algorithms

Chair: Amir Khodabandeh (Australia)
Affiliation:Comm. 1, 4 and GGOS

Introduction

In recent years, we are witnessing rapid development in the satellite-based navigation and positioning systems. Next to the modernization of the GPS dual-frequency signals to the triple-frequency signals, the GLONASS satellites have been revitalized and become fully operational. The new global and regional satellite constellations are also joining the family of the navigation systems. These additions are the two global systems of Galileo and BeiDou satellites as well as the two regional systems of QZSS and IRNSS satellites. This namely means that many more satellites will be visible to the GNSS users, transmitting data on many more frequencies than the current GPS dual-frequency setup, thereby expecting considerable improvement in the performance of the positioning and non-positioning GNSS applications.

Such a proliferation of multi-system, multi-frequency data demands rigorous theoretical frameworks, models and algorithms that enable the near-future multiple GNSSs to serve as a high-accuracy and high-integrity tool for the Earth-, atmospheric- and space-sciences. For instance, recent studies have revealed the existence of non-zero inter-system and inter-system-type biases that, if ignored, result in a catastrophic failure of integer ambiguity resolution, thus deteriorating the corresponding ambiguity resolved solutions. The availability of the new multi-system, multi-frequency data does therefore appeal proper mathematical models so as to enable one to correctly integrate such data, thus correctly linking the data to the estimable parameters of interest.

Objectives

The main objectives of this study group are:

• to identify and investigate challenges that are posed by processing and integrating the data of the next generation navigation and positioning satellite systems,
• to develop new functional and stochastic models linking the multi-GNSS observations to the positioning and non-positioning parameters,
• to derive optimal methods that are capable of handling the data-processing of large-scale networks of mixed-receiver types tracking multi-GNSS satellites,
• to conduct an in-depth analysis of the systematic satellite- and receiver-dependent biases that are present either within one or between multiple satellite systems,
• to develop rigorous quality-control and integrity tools for evaluating the reliability of the multi-GNSS data and guarding the underlying models against any mis-modelled effects,
• to access the compatibility of the real-time multi-GNSS input parameters for positioning and non-positioning products,
• to articulate the theoretical developments and findings through the journals and conference proceedings.

Program of activities

While the investigation will be strongly based on the theoretical aspects of the multi-GNSS observation modelling and challenges, they will be also accompanied by numerical studies of both the simulated and real-world data. Given the expertise of each member, the underlying studies will be conducted on both individual and collaborative bases. The outputs of the group study is to provide the geodesy and GNSS communities with well-documented models and algorithmic methods through the journals and conference proceedings.

Members

Amir Khodabandeh (Australia), chair
Peter J.G. Teunissen (Australia)
Pawel Wielgosz (Poland)
Bofeng Li (China)
Simon Banville (Canada)
Nobuaki Kubo (Japan)
Ali Reza Amiri-Simkooei (Iran)
Gabriele Giorgi (Germany)
Thalia Nikolaidou (Canada)
Robert Odolinski (New Zealand)