The Navigation Support Office is based at ESOC's Navigation Facility, which provides products and services related to global navigation satellite systems in support of ESA missions and to European customers such as Eumetsat and to worldwide customers through its participation in the International Global Navigation Satellite Systems (IGNSS) Services group.

The core service consists of calculating and predicting highly accurate GPS, Galileo and GLONAS satellite orbits, in near-real time, every six hours, around the clock. These data are then used to improve GPS position accuracy, paving the way to even more sophisticated applications such as scientific studies, large-scale climate monitoring and tracking of long-term changes in Earth’s geology.

More about ESA Navigation Support Office:
http://www.esa.int/Our_Activities/Operations/Ground_Systems_Engineering/ESA_Navigation_Support_Office