5:45 PM - 6:00 PM
[G03-1-05] Status of development on the future accelerometers for next generation gravity missions
The GRACE FO mission, led by the JPL and GFZ, is an Earth-orbiting gravity mission, continuation of the GRACE mission, which will produce an accurate model of the Earth's gravity field variation providing global climatic data during five years at least. Europe and US propose new gravity missions beyond GRACE-FO, with performance improved thanks to laser interferometry and better accelerometers. ONERA has procured the accelerometers for the previous geodesic mission (CHAMP, GRACE, GOCE and now GRACE-FO) and continue to improve the instruments to answer to the challenge of the future missions according to two main axes:
Firstly, a new design of electrostatic accelerometer is proposed, based on MicroSTAR configuration, a 3-axes ultra-sensitive accelerometer, with a cubic proof-mass. This new design gives, beyond the linear acceleration, the 3 angular accelerations for a better satellite attitude control. For linear acceleration, the performance is improved by at least an order of magnitude with respect to GRACE-FO.
Secondly, ONERA studies the hybridization of such electrostatic accelerometer with cold atom interferometer technology. Each of these two types of instruments presents their own advantages which are, for the electrostatic sensors, their demonstrated short term sensitivity and their high TRL, and for atom interferometer, the absolute nature of the measurement and therefore no need for calibration processes. These two technologies are very complementary and a hybrid sensor could be the opportunity to make a big step in this context of gravity space missions. We present here the first experimental association on ground of an electrostatic accelerometer and an atomic accelerometer and underline the interest of calibrating the electrostatic sensor with the atomic interferometer.
Firstly, a new design of electrostatic accelerometer is proposed, based on MicroSTAR configuration, a 3-axes ultra-sensitive accelerometer, with a cubic proof-mass. This new design gives, beyond the linear acceleration, the 3 angular accelerations for a better satellite attitude control. For linear acceleration, the performance is improved by at least an order of magnitude with respect to GRACE-FO.
Secondly, ONERA studies the hybridization of such electrostatic accelerometer with cold atom interferometer technology. Each of these two types of instruments presents their own advantages which are, for the electrostatic sensors, their demonstrated short term sensitivity and their high TRL, and for atom interferometer, the absolute nature of the measurement and therefore no need for calibration processes. These two technologies are very complementary and a hybrid sensor could be the opportunity to make a big step in this context of gravity space missions. We present here the first experimental association on ground of an electrostatic accelerometer and an atomic accelerometer and underline the interest of calibrating the electrostatic sensor with the atomic interferometer.