| 1. | Earth Observation - Mission accomplished for GOCE and its ONERA g-meters |
| | After two years in orbit and gathering gravity data, which will have taken over 12 months, the GOCE mission is a remarkable scientific success.... At the heart of this success is a measurement instrument that is a pioneer in space : a triaxial gradiometer designed to measure terrestrial gravity.... |
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| 2. | Clients and Partners - Onera |
| | Supplier to ESA of six ultra-sensitive accelerometers for the Goce fundamental physics mission, designed to measure anomalies in the Earth's gravity field.... |
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| 3. | Einstein and the accelerometer - Zoom in the Lab |
| | The basis of the theory of relativity is the principle of equivalence, which postulates that inertial mass (measuring the inertia of a body, its resistance to movement) and gravitational mass (the experience of gravity, in particular, of the Earth) are one and the same.... Each acceleration, whether due to gravity or the movement of the instrument, makes the mass move inside the cage.... |
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| 4. | GOCE, a space mission exploring terrestrial gravity |
| | GOCE, a space mission exploring terrestrial gravityWho are we ?News Releases april 2008... GOCE, a space mission exploring terrestrial gravity. The Goce [ ESA ] satellite is officially ready for its departure.. Its mission will be to accurately measure the gravity on the surface of our globe - extreme measurements but within the capabilities of the Onera's ultra-sensitive accelerometers.. |
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| 5. | - ONERA / DMPH |
| | In the MICROSCOPE space experiment, the in-orbit motions of two masses falling in the Earth gravity field are controlled symmetrically taking care that both masses are submitted exactly to the same gravitational field.... The fluctuations of the gravity gradients are limited at the test frequency bandwidth because of the selected satellite orientation and the small orbit eccentricity, less than 5.10-3. Steady thermal environment is expected, down to 1 mK for the sensors including the test masses ; passive control of the experiment device has been tested sufficient with the selected heliosynchronous orbit preserving the satellite orientation to the Sun radiation along the orbit.... |
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| 6. | - ONERA / DMPH |
| | The difference of the electrostatic applied forces is finely measured and correlated to the Earth gravity field in order to detect an eventual signal of EP violation.... The stability of these orientations, down to 0.1 µrd level, is mandatory to limit by the satellite fine pointing the disturbing effects from gravity and cinematic acceleration gradients.... |
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| 7. | Satellite Attitude Control Using CMG - ONERA / DCSD-EN |
| | When the gimbal becomes free, the gravity torque drives it around the horizontal axis, perpendicular to the symmetry plane, until it falls on the stop.... This control aims to keep the center of gravity of the gimbal assembly over the rotation axis.... The commanded precession rate is such that the gyroscopic torque counterbalances the gravity torque and the disturbing torques (as shown by the operator).... |
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| 8. | Inertial measurements with cold atom devices - ONERA / DMPH-EN |
| | Once cold, the trap is switched off and the atoms fall in the gravity field.... The result is an interference phenomenon, and the phase difference between the two paths is directly proportional to the acceleration of gravity g. This type of measurement is used to measure g with a precision better than 10-9.... |
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| 9. | Ultra-sensitive Accelerometry and Space Projects - Earth and Planetary Observation - ONERA / DMPH-EN |
| | 10 cm in terms of geoid height or 0.5 mgal in terms of gravity anomaly for a geographic resolution / 2 of 550 km.... Its resolution is 5 cm for the geoid and 0.5 mgal in terms of gravity anomaly, with / 2 reduced to 400 km.... In 2003, two new Earth gravity field models, Eigen-GRACE - 01S and GGM01, were developed from the first GRACE data.... |
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| 10. | WP3 [ DART ] |
| | Weight and centre of gravity location calculations.... |
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