Third Party Activities

GRAS Ground Support Network (GSN)

Different customers have different needs. One important customer for the Navigation Facility is the Metop mission operated by EUMETSAT. For the exploitation of its GNSS Receiver for Atmospheric Sounding (GRAS) payload, which delivers atmospheric profiles to the European Met offices, EUMETSAT requires GPS products with a guarantee on accuracy, availability and latency. To deliver this service, the Navigation Facility now hosts the operation of the GRAS Ground Support Network (GSN), which is a dedicated network of 45 stations. It has been operating successfully for five years, delivering products with a latency of only 45 minutes, and an availability of better than 99 percent. Based on these, EUMETSAT delivers a daily set of more than 500 atmospheric profiles (and double that number as soon as Metop-2 will be operational) to the European Met offices, a data set that has already become one of the key elements in numerical weather prediction.

As an example for Navigation Office activities related to Metop, see the basic principle below:

The Metop satellites can “see” the lower flying GPS satellite, they can capture the GPS navigation signals via an onboard GPS receiver. As these GPS signals travel through the upper atmosphere, they are affected in ways that, though specialised processing, the Navigation Support Office provide valuable data on the ionosphere and troposphere, including the concentration of charged ions, and temperature, pressure and humidity measurements. Read more



The Navigation Support Office is in close cooperation with Fugro Satellite Positioning for the provision of high-accuracy real-time worldwide positioning using several GNSS (GPS, GLONASS, BeiDou and Galileo). The system, being commercialised as G4, benefits from Fugro expertise in real-time navigation, together with the Navigation Support Office profound knowledge on GNSS processing. Read more