Orateur
Description
Space gravimetry missions such as GRACE or GOCE determine the Earth
gravity field with great accuracy [1]. The data gathered are very useful in
the sciences of climatology, hydrology or geophysics and to understand global
climate change. These missions board state-of-the-art space electrostatic accelerometers
displaying a very good sensitivity but also a long-term drift. By
combining an electrostatic accelerometer with a very stable cold atom accelerometer,
it is possible to correct this drift. To this day, no acceleration
measurements with a cold atom accelerometer has been performed in space,
mostly because of the harmful effect of the satellite’s rotation on the interferometer
output [2].
In this paper, we present our ongoing experimental work concerning the
development of a hybridised electrostatic/atomic accelerometer. In particular,
we addressed the problematic of satellite’s rotation and its detrimental effect
on the cold atom interferometer. The hybrid lab prototype is made of an
electrostatic accelerometer and a cold atom interferometer. The test mass
of the electrostatic accelerometer, very well controlled in angle and position,
is employed as the retro-reflection mirror of the interferometer. By rotating
the test mass, we studied the impact of inertial acceleration on the atomic
interferometer contrast and phaseshift. Moreover, we are working on the
rotation compensation technique: the test mass is rotated in order to limit
the impact of the whole instrument’s rotation [3].
[1] S. Cesare and al. The European way to gravimetry: From GOCE to
NGGM, Advances in Space Research 57, 1047 (2016).
[2] S. Lan and al. Influence of the Coriolis Force in Atom Interferometry,
Physical Review Letters 108, 090402 (2012).
[3] N. Zahzam and al. Hybrid electrostatic-atomic accelerometer for future
space gravity missions, Remote Sensing, 14(14),3273 (2022).
| Affiliation de l'auteur principal | DPHY, ONERA-The French Aerospace Lab, Palaiseau, France |
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