UAV geophysical surveys for mineral exploration in challenging environments

Uncrewed aerial vehicles (UAVs) equipped with geophysical sensors have brought numerous advancements to modern geophysics, enabling cost-effective exploration and high-resolution analysis of geological anomalies. Integrating multiple sensors through UAV platforms proves especially advantageous in prospecting for mineral resources. Over the last years, our team has developed and rigorously tested in-house UAV systems carrying magnetometers, gamma-spectrometers, LiDAR, and hyperspectral sensors. Ensuring good data quality presents several challenges specific to UAVs. One significant challenge arises during aeromagnetic surveys conducted in regions with remarkably high magnetic gradients. These gradients have a substantial impact on the UAV’s essential navigation instruments, endangering the aircraft and leading to data disturbances. To showcase the potential of our approach, we have successfully deployed the systems in various challenging environments worldwide, including areas with high magnetic gradients, low GPS coverage, sharp topographic variations, extreme temperatures, and strong wind gusts.

We introduce a robust workflow designed to acquire and process UAV aeromagnetic data effectively. For the surveys, we employ the Sensys MagDrone R3 magnetometer strategically positioned at a 2m distance from the UAV using an extensible arm, eliminating magnetic interferences from the carrier. Additionally, data grids are meticulously designed based on the geological target, unraveling geological complexities. Data processing is performed through a Python toolbox, allowing us to promptly assess data quality during survey operations and to make well-informed decisions on-site. This approach has been validated across contrasting environments to tailor the acquisition strategy to local conditions, leading to the most optimal dataset possible at each location.

Through multiple case studies, we successfully demonstrate the capabilities of UAV magnetic surveys, often providing the highest resolution airborne survey data in the regions to date. The level of detail and accuracy achieved with UAV magnetic surveys opens up new possibilities for gaining deeper insights into complex structures and accurately pinpointing promising
mineral deposits with unprecedented precision.