Vibration Compensation for a Vehicle-Mounted Atom Gravimeter

Abstract

The performance of absolute atom gravimeters used on moving platforms, such as vehicles, ships and aircrafts, is strongly affected by the vibration noise. To suppress its influence, we introduce a vibration compensation method, in which a classical accelerometer is used to measure the vibration noise. The measurement results obtained by the accelerometer show the vibration noise in the vehicle can be 2 orders of magnitude greater than that in the lab during daytime, and can induce an interferometric phase fluctuation with a standard deviation of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$16.70\pi $ </tex-math></inline-formula> . With the compensation method, our vehicle-mounted atom gravimeter can work normally under harsh conditions. Comparing the Allan standard deviations before and after the vibration noise correction, we find a suppression factor of 22.74 can be achieved in static condition with a half interrogation time of T = 20 ms, resulting in a sensitivity of 1.35 mGal/Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> , and a standard deviation of 0.5 mGal with an average time of 10 s. We also demonstrate the first test of an atom gravimeter in a moving vehicle, in which a suppression factor of 50.85 and a sensitivity of 60.88 mGal/Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> were realized with T = 5 ms.