Gravity measurements below $10^{-9}$ $g$ with a transportable absolute quantum gravimeter

TL;DR

This paper introduces a transportable quantum gravimeter capable of measuring absolute gravity with sub-10 nm/s² stability, suitable for field use by non-specialists, combining high precision with portability.

Contribution

The authors developed and demonstrated a portable quantum gravimeter that maintains laboratory-level sensitivity and stability in real-world conditions, enabling broader geophysical applications.

Findings

Achieved stability below 10 nm/s² over a month-long measurement.

Successfully operated the gravimeter in field conditions by non-specialists.

Maintained high-precision measurements with a compact, lightweight design.

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~$\mu$Gal). 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.