Tracking the vector acceleration with a hybrid quantum accelerometer triad

Abstract

Robust and accurate acceleration tracking remains a challenge in many fields. For geophysics and economic geology, precise gravity mapping requires onboard sensors combined with accurate positioning and navigation systems. Cold atom–based quantum inertial sensors can potentially provide these high-precision instruments. However, current scalar instruments require precise alignment with vector quantities. Here, we present the first hybrid three-axis accelerometer exploiting the quantum advantage to measure the full acceleration vector by combining three orthogonal atom interferometer measurements with a classical navigation-grade accelerometer triad. Its ultralow bias permits tracking the acceleration vector over long time scales, yielding a 50-fold improvement in stability (6 × 10 −8 g ) over our classical accelerometers. We record the acceleration vector at a high data rate (1 kHz), with absolute magnitude accuracy below 10 μ g , and pointing accuracy of 4 μrad. This paves the way toward future strapdown applications with quantum sensors and highlights their potential as future inertial navigation units.

Emulating an Atomic Gyroscope with Multiple Accelerometers

“…In order to properly compare the long-term stability of the angular velocity measurement made by an AAA, we model the statistical properties of the atomic accelerometers from Ref. 20 . Namely a single-shot measurement resolution of 7.6×10 −5 ms −2 , and a bias drift of 5.9 × 10 −7 ms −2 /day.…”

“…Even for very large arrays with l = 2.0 m, the attainable single-shot resolution of ∼ 10 −5 rad•s −1 is greatly outperformed by state of the atomic gyroscopes, whose single-shot resolution is on the order of ∼ 10 −8 − 10 −9 rad•s −135 . The single-shot resolution of the AAA can be improved upon by introducing additional accelerometers, however, the most practical way of rivaling atomic accelerometers is by hybridizing the array of accelerometers with classical sensors 15,20 ; note that this does not defeat the purpose of an AAA, as their most impactful contribution is long-term stability.…”

“…Atomic interferometry has undergone rapid technological developments in the past few decades [1][2][3][4] , leading to highly sophisticated technologies that can be used for a variety of precision measurements, including, but not limited to, Earth's gravity [5][6][7][8][9] , the fine structure constant 10,11 and the Aharonov-Casher effect 12 . Another promising application of atomic intereferometers is navigation and inertial sensing [13][14][15][16][17][18][19][20] , i.e. as an accelerometer or gyroscope.…”

“…We assume that the atomic accelerometers are simultaneously sensitive to three different axis of acceleration. Although such devices exist, the measurements are sequential and not simultaneous 13,20,47 , however, assuming the time delay between measurements is small, than this approximation may still hold. Alternatively, one can use a different setup with single-axis atomic accelerometers placed strategically 42 and obtain simultaneous measurement results.…”

“…accelerometers with realistic resolutions 20,40,41 and subjecting the array to different degrees of rotational motion. We investigate how a bias drift within the atomic accelerometers translates to an effective bias drift with respect to the angular velocity measurement.…”