First Quantum Mineral Ltd (link to www.first-quantum.com) is one of the world’s top 10 copper producers, with long life operations in several countries, exporting millions of tonnes of concentrate to customers worldwide. The company is continuously looking for efficient, sustainable and less invasive solutions in all its operations, while striving to meet its customer’s expectations.

In order to meet the ever growing demands for natural resources, First Quantum is involved in several exploration projects around the world, one of which is located in Eastern Lapland. Geophysical characterisation of the area proved to be challenging for traditional methods of airborne surveying, however Radai’s highly-customized field survey method provided a solution in this case.

The field study was completed over 2 campaigns between July-August 2020. The exploration area is located in a sparsely populated part of Finland. The main objective and outcome of the survey was to improve geological mapping of the selected survey area. The compounded surface of surveyed areas was 240km2 and was made using multiple Albatros VT2 UAVs. The surveyed area was covered by 69 flights, measuring over 5453 line km – one of the longest in Radai’s history.

The survey was made beyond visual line-of-sight (BVLOS) operational mode with the permission of Finland aviation authorities. Radai’s magnetic measurement system was installed into a custom-made UAV fixed-wing plane (Albatros VT2). Survey system included a magnetometer, datalogger and multiple other sensors; GPS, barometer, voltage and currency sensors and plenty of others.

After take-off, the flight was controlled by an autopilot that guided the drone through a predefined set of waypoints. The flight path followed terrain topography defined by a digital elevation model (DEM) which was provided by the National Land Survey of Finland.

The flight performance was controlled by a PC software via telemetry (radio) link and redundant connection was established via wireless mobile GSM link in real time. Separate GSM based tracker devices enabled the UAV to be tracked in case of lost telemetry signal or an unwanted crash. Magnetic base station near the mobile telemetry/control station measured the temporal variation of the magnetic field and the barometric pressure.

In the post-processing of the data, the magnetic data of the moving UAV platform, and optionally the flight height, were corrected by the temporal changes observed at the base station. The data processing was made using the interactive RadaiPros (v. 2.2d) software created by our Chief Geophysicist Dr. Markku Pirttijärvi.