The map above shows the GPS Dancer processes that are currently on-line. You can click on it to open a larger version.

During the test period three processes will be kept running permanently, for the collection of network endurance statistics. This data is mainly used for the tuning of communication time-out intervals on the real internet, and for optimization of data package sizes.

One of the three sites (ALGO) acts as public JXTA rendez-vous peer. In the future operational Dancer network there will be multiple rendezvous peers, in order to avoid a single-point-of-failure in the Dancer system. The GPS Dancer process for ALGO is not actually running at the Algonquin observatory, but on a cloud computing server in Montabaur (Germany) with unlimited bandwidth.

The two other "permanent" test sites are running on varying computers in the world. They are not really permanent, because every now and then a new process - for another GPS station - is launched after which either of the two previous "permanent" Dancer processes is taken off-line.

If you happen to see fewer than three active processes on the map above, some anomaly has occurred! This is usually a step forward: the whole point of testing is to identify and resolve any remaining anomalies in the software or network communication.

More and more frequently, a larger network of Dancer processes is on-line for global testing. If you are very lucky you may see up to 50 active stations, but usually this does not last for more than three hours. These processes are running on a commercial cloud computing provider, and even though this is very cheap (...about 5 EUR per day for a 100 station network) the resources available for such testing are limited.

The next target in the deployment of the Dancer network is to arrive at a stable routine process for all ~450 ITRF reference stations. The issues to be resolved are not so much technical, but mainly organisational and financial. Various approaches are being studied - please come back soon to see if we are making progress!

Project details

Ultimate Browsers SupportThe GPS Dancer project started in 2007 as a voluntary project of a working group of the International Association of Geodesy.

Read more ...

Square dance algorithm

Great Docs and SupportThe GPS Dancer system was named after its "square dance" exchange algorithm. Of course, it also wants to to make the GPS reference frame denser.


Here, there be pirates

The Dancer on-line network became immune against internet connection problems by leaving the US marines, and becoming a pirate.

Read more ...

Go to top