A new Approach for GNSS Analysis in a Multi-GNSS and Multi-Signal Environment

Over the coming years GPS and GLONASS will be modernised, whilst at the same time new systems like QZSS, Galileo, and Compass are launched. The modernisations of the existing and the deployment of new Global Naviagation Satellite Systems (GNSS) will make a whole range of new signals available to the users. The anticipated improvements will strongly depend on our understanding and handling of the biases that will inevitably exist between the different systems and signals. Furthermore the extremely high stability of the future satellite clocks means, that any form of differencing observations to cancel out the satellite clock offsets, effectively leads to a very significant loss of information. The fundamentally new aspect of our approach for GNSS analysis in a multi-GNSS and multi-signal environment is that it avoids the formation of differences as well as of linear combinations. Thus all available observations from all GNSS systems as observed by all the receivers in a network are incorporated in the parameter estimation. The fact that all observations are analysed without any pre-selection of observation types, needed for linear combinations or observation differences, leads to an enormous simplification of the processing.