Gravity measurements below 10−9 g with a transportable absolute quantum gravimeter

Abstract

Gravimetry is a well-established technique for the determination of sub-surface mass distribution needed in several fields of geoscience, and various types of gravimeters have been developed over the last 50 years. Among them, quantum gravimeters based on atom interferometry have shown top-level performance in terms of sensitivity, long-term stability and accuracy. Nevertheless, they have remained confined to laboratories due to their complex operation and high sensitivity to the external environment. Here we report on a novel, transportable, quantum gravimeter that can be operated under real world conditions by non-specialists, and measure the absolute gravitational acceleration continuously with a long-term stability below 10 nm.s−2 (1 μGal). It features several technological innovations that allow for high-precision gravity measurements, while keeping the instrument light and small enough for field measurements. The instrument was characterized in detail and its stability was evaluated during a month-long measurement campaign.

Short‐Time Geodetic Determination of Aquifer Storage Coefficient in Taiwan

“…This scenario does not need a pumping well, thus greatly reducing the cost. In view of the current advancements in gravimeter accuracy, transportability, and resilience (Menoret et al, ; Van Camp et al, ), a successful S y estimation from such short‐time gravity measurements can be very likely.…”

“…This scenario does not need a pumping well, thus greatly reducing the cost. In view of the current advancements in gravimeter accuracy, transportability, and resilience (Menoret et al, 2018;Van Camp et al, 2017), a successful S y estimation from such shorttime gravity measurements can be very likely. silt/mud layer stretches from 41 to 45 m and a thin-layer sand from 56.5 to 76 m. Thus, we assume that the unconfined aquifer at Neicheng covers the depths from 0 to 41 m.…”

Optical characterisation of micro-fabricated Fresnel zone plates for atomic waveguides

“…Atom guiding is of particular interest to us as it has the potential to reduce the size of experiments from tens of meters, to something even smaller than the portable 'fountain' systems already demonstrated [20,21]. While ring-guided ultracold atom interferometers have long been a goal [19,22], actual rotation metrology has only been achieved very recently [23,24].…”

Improving the accuracy of atom interferometers with ultracold sources

“…They offer the possibility to perform high repetition rate continuous measurements over extended periods of time [3,4], which represents an operation mode inaccessible to other absolute gravimeters that suffer from mechanical wear. These features have motivated the development of commercial cold atom gravimeters [5], addressing in particular applications in the fields of geophysics. Nevertheless, the accuracy of these sensors, though comparable, is today slightly worse.…”