ECA GROUP, expert in the development of satellite tracking systems, has furnished the French National Centre for Space Studies (CNES) with DORIS beacons since the 1980s. Since then, ECA GROUP has been developing three generations of ground beacons for the CNES’s DORIS system. In 2020, ECA GROUP delivered 20 beacons, and in the coming two years, the company will deliver 50 more for the renewal of the CNES’s satellite stations.
DORIS is a name given to the French space system for precise orbit determination and positioning that includes ECA GROUP’s ground beacons. The system has been developed by the CNES and the French National Institute of Geographic and Forest Information (IGN). DORIS stands for Doppler Orbitography and Radiopositioning Integrated by Satellites. The beacons work like an ‘inverted GPS’ as they send a signal from the ground to the satellite to know its correct position in orbit. The DORIS beacons send out a signal every 10 seconds in two different frequencies, allowing measurements with ultimate precision, thanks to a bench built by ECA GROUP and an antenna from COBHAM.
DORIS beacon in Saint Helena (South Atlantic): Beacons consist of an antenna and three boxes.
In the 1980s, the beacon’s measurements served only to localize the exact positon of a satellite. Today, the beacons contribute to analyzing climate change as they participate in measuring rising sea levels as well as the change in height of the Antarctic ice sheet.
Known to scientists, but still a surprise to the public: DORIS beacons have also proven the earth’s slight deformation. To the naked eye a perfect “blue marble”, our planet is in reality the shape of a football that lost air over time, slightly squashed at its poles and swollen at the equator.
DORIS is a microwave tracking system. It uses a network of 60 ground stations that send a radio-electric signal out to orbit – to the on-board receivers of satellites like SPOT, JASON, ENVISAT, CRYOSAT and SENTINEL 3 and 6.
The system works on the principle of the Doppler effect: The frequency of a wave changes when a transmitter and a receiver are in relative motion to each other. The frequency increases as the two objects get closer and decreases as they move apart. A simple example is the drop in pitch of an ambulance siren as it passes by.
The DORIS system uses this effect as it transmits and receives radiofrequency waves.
And these radiofrequency waves can help us analyse ocean levels and glacial melting or they can support us in cartography – science in the service of nature’s wonders, but also in the service of bigger concerns – climatic change.
Photorights: © CNES/ill./DUCROS David, 2013
Developed by ECA Group, the "all-in-one" device aWAP-MS is now on-board Hawker...
Read MoreMeet ECA Group at SATELLITE 2022 - Washington DC, USA and discover our antenna tracking system,...
Read MoreMeet ECA Group at the AEEC | AMC (Airlines Electronic Engineering Committee (AEEC) & Aviation...
Read MoreMeet ECA Group at MRO EUROPE 2022 October 19-20 to discover our solutions in Aerospace Testing,...
Read MoreMeet ECA Group at the 25th ESA European Rocket and Balloon Research Symposium from May 1st to...
Read MoreECA GROUP’s first autonomous logistics was delivered to French supply chain provider IDEA....
Read MoreMEET ECA GROUP AT APEX EXPO 2021 | LONG BEACH CA USA | NOVEMBER 30 - DECEMBER 2 AND...
Read MoreAssuring aviation safety since 1993: Major aircraft manufacturers and 350 airlines fly with...
Read MoreMeet ECA GROUP at AEROSPACE TECH WEEK 2021 - November 3-4 and discover our solutions in aerospace...
Read MoreECA Group will exhibit its Aviation Training Simulation Solutions at European Airline...
Read More