Graves (System)
Encyclopedia
GRAVES is a French radar
-based space surveillance system, akin to the American NAVSPASUR. Using radar measurements, the French Air Force
is able to spot satellite
s orbiting the Earth and determine their orbit
. The GRAVES system took 15 years to develop, and became operational in November, 2005.
GRAVES is a bistatic radar
system using Doppler
and directional information to derive the orbits of the detected satellites. Its operating frequency is 143.050 MHz, with the transmitter being located on a decommissioned airfield near Broye-lès-Pesmes at 47.3480°N 5.5151°E and the receiver at a former missile site near Revest du Bion on the Plateau d'Albion at 44.0715°N 5.5346°E. Data processing and generation of satellite orbital elements
is performed at the Balard Air Complex in Paris, 48.835°N 2.280°E.
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
-based space surveillance system, akin to the American NAVSPASUR. Using radar measurements, the French Air Force
French Air Force
The French Air Force , literally Army of the Air) is the air force of the French Armed Forces. It was formed in 1909 as the Service Aéronautique, a service arm of the French Army, then was made an independent military arm in 1933...
is able to spot satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
s orbiting the Earth and determine their orbit
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...
. The GRAVES system took 15 years to develop, and became operational in November, 2005.
GRAVES is a bistatic radar
Bistatic radar
Bistatic radar is the name given to a radar system which comprises a transmitter and receiver which are separated by a distance that is comparable to the expected target distance. Conversely, a radar in which the transmitter and receiver are collocated is called a monostatic radar...
system using Doppler
Doppler radar
A Doppler radar is a specialized radar that makes use of the Doppler effect to produce velocity data about objects at a distance. It does this by beaming a microwave signal towards a desired target and listening for its reflection, then analyzing how the frequency of the returned signal has been...
and directional information to derive the orbits of the detected satellites. Its operating frequency is 143.050 MHz, with the transmitter being located on a decommissioned airfield near Broye-lès-Pesmes at 47.3480°N 5.5151°E and the receiver at a former missile site near Revest du Bion on the Plateau d'Albion at 44.0715°N 5.5346°E. Data processing and generation of satellite orbital elements
Orbital elements
Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are generally considered in classical two-body systems, where a Kepler orbit is used...
is performed at the Balard Air Complex in Paris, 48.835°N 2.280°E.