DroneSOM—Towards a Drone-Based Gravity Observation System

Abstract In this article we present the challenges, practical limitations together with results and current status of two drone-based gravity systems developed within an EU EIT Raw Materials funded project DroneSOM. Both systems have a maximum take-off weight below 25 kilograms simplifying the application procedure for obtaining beyond-visual-line-of-sight permits from relevant aviation authorities. The two systems apply the strapdown gravimetry technique using a navigation-grade inertial measurement unit and geodetic GNSS antenna as sensor payload. The fixed-wing system is designed towards mapping of larger areas, while the quadcopter system can obtain a higher spatial resolution through its lower flight speed. We also tested hovering-based observations for point-based observations of the Earth’s gravity field. Results of two quadcopter campaigns obtain a root mean square of 2–3 mGal along repeated flight lines after accounting for IMU cross-coupling errors. Comparison of turbulence estimator with traditional aircraft campaigns, and the large reduction in repeat line root mean square when including cross-coupling errors show that IMU-errors are the dominant factor compared to GNSS for drone-based gravity measurements.