the ultra sensitive accelerometers of the esa goce mission

Paper number

IAC-08.B1.3.7

Author

Mr. Jean-Pierre Marque, Office National d’Etudes et de Recherches Aérospatiales (ONERA), France

Coauthor

Mr. Bruno Christophe, Office National d’Etudes et de Recherches Aérospatiales (ONERA), France

Coauthor

Dr. Bernard Foulon, Office National d’Etudes et de Recherches Aérospatiales (ONERA), France

Coauthor

Mrs. Françoise Liorzou, Office National d’Etudes et de Recherches Aérospatiales (ONERA), France

Coauthor

Dr. Bodovillé Guillaume, France

Coauthor

Mr. Guerard Jean, France

Coauthor

Mr. Vincent Lebat, Office National d’Etudes et de Recherches Aérospatiales (ONERA), France

Year

2008

Abstract

By combining satellite Gradiometry with SST-high-low GPS tracking, the ESA GOCE mission aims to provide a high resolution Gravity Field to the Scientific and Engineering communities. Continuous 3D GPS tracking of the satellite and compensation of non-gravitational forces, thanks to on–board accelerometers, opens the way to the measurement of the difference in gravitational acceleration at the accelerometers position. The short baseline of the instrument (50 cm) allows us to interpret this value as the second derivative of the gravitational potential; the effect of double derivation balances the altitude attenuation of the potential to permit observation of the gravity field with an unprecedented accuracy of 1-2 mgal and resolution of 100 km at the highest order.

The Gradiometer is the 3D instrument which makes this measurement possible along the in-track and cross-tracks directions, is made of:
•3 accelerometer pairs (sensors and electronic units)
•Ultra stable Carbon-carbon structure to support the accelerometer
•Accurate passive and active thermal control

The paper will describe the 6 accelerometers provided by ONERA together with the test plan developed to guarantee a level of noise acceleration as low as  2.0 10-12  ms-2 Hz-1/2 as required by the mission scientific performance.
The accelerometers are based on a principle similar to the ones embarked on GRACE Tom & Jerry satellites but with some technological evolution to improve their resolution by 2 orders of magnitude.
Their contribution to the mission is double by providing the S/C with the linear accelerations as input to the continuous Drag-Free system and with the measured scientific to be on-ground processed.
Results of the dedicated on-ground test including Free fall test will be presented for the 6 accelerometers.

The launch date of the GOCE mission is 2008, May 31st. 

The accelerometers of the GOCE mission have been developed by ONERA under contract with ThalesAleniaSpace France as Prime Contractor of the Gradiometer.

Abstract document

IAC-08.B1.3.7.pdf

Manuscript document

IAC-08.B1.3.7.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.