Live Performance Monitoring
The ultimate quality metric of a differential positioning system is, of course, positioning. To demonstrate the key attributes of the GDGPS System, namely, global coverage, outstanding accuracy, and high real-time reliability, we present in this page the live, real-time positioning performance of select stations at widely separated locations.
At each location a dual-frequency GPS receiver is streaming its measurements to a GDGPS Operations Center (GOC). At the GOC we also calculate the real-time orbit and clock states of the GPS satellites based on such data streams from nearly 250 receivers spread all over the world. In a separate point positioning process we use the precise real-time orbit and clock states to position the three receivers in real-time.
The station receivers may or may not have contributed their data to the GPS orbit determination process. But with so many receivers contributing their data, any one receiver has negligible impact, and it does not skew the point-positioning results.
Below you can see the accuracy of the real-time positioning measured against the surveyed location of the antenna. The point-positioning is done kinematically at 1 Hz, that is, at each second we estimate a new location with no assumptions on the velocity (which is zero, of course).
Real-time Station Performance
Madrid, Spain (MADR)
Diego Garcia (DGAR)
Greenbelt, Maryland, USA (GODE)
Frankfurt, Germany (FFMJ)
