Global GPS reference frame solutions of unlimited size Original Research Article

This paper reports on the Dancer project, which is one of three related projects initiated by working group 1 of the International Association of Geodesy. The Dancer project develops JAVA parameter estimation software that runs in the form of a distributed process on the internet, in such a way that each processing node handles the data of a single geodetic instrument. By exchanging a minimum amount of information among all processing nodes, the same global normal equation solution is found by all instruments. The result is a fully scalable least squares solution that has no practical limit to the number of GPS receivers or other tracking devices that may be included in a single reference frame realization. High-end GPS users will also be able to run a Dancer process for their own data, without contributing to the reference frame solution but taking full advantage of its global consistency. This offers direct access to precise International Terrestrial Reference Frame and UTC realizations, anywhere on Earth where there is an internet connection. Mission control centres of low satellites with GPS receivers can run a Dancer process on the incoming data from the orbiting receiver, to introduce strong ties with other techniques such as Satellite Laser Ranging.