We report an airborne gravity survey with an absolute gravimeter based on atom interferometry and two relative gravimeters: a classical LaCoste&Romberg (L&R) and a novel iMAR strap-down Inertial Measurement Unit (IMU). We estimated measurement errors for the quantum gravimeter ranging from 0.6 to 1.3 mGal depending on the flight conditions and the filtering used. Similar measurement errors are obtained with iMAR strapdown gravimeter but the long term stability is five times worse. The traditional L&R platform gravimeter shows larger measurement errors (3 - 4 mGal). Airborne measurements have been compared to marine, land and altimetry derived gravity data. We obtain a good agreement for the quantum gravimeter with standard deviations and means on differences below or equal to 2 mGal. This study confirms the potential of quantum technology for absolute airborne gravimetry which is particularly interesting for mapping shallow water or mountainous areas and for linking ground and satellite measurements with homogeneous absolute referencing.

Key Points

Unlike classical systems, a quantum gravimeter does not require calibrations ordrift estimations during an airborne gravity campaign

A quantum gravimeter has demonstrated similar precision than an IMU gravimeter and significantly better precision than a spring gravimeter

A quantum gravimeter has shown significantly better long term stability than an IMU strapdown system even if its drift has been corrected

Plain Language Summary

Quantum technology offers a new kind of sensor for airborne gravimetry. Contrary to classical technologies which can only measure variation of gravity from an aircraft, a quantum gravimeter provides directly an absolute measurement of gravity eliminating the necessity of calibrations and drift estimations. We report here an airborne survey with a quantum gravimeter and two classical gravimeters. We demonstrated that the quantum gravimeter reaches the same precision than the best classical gravimeter. The gravity measurements have also been validated with models derived from land and marine gravity measurements and satellite altimetry.