Eye in the sky
Using drone technology.
New aerial and satellite surveillance techniques are providing another tool for the Department for Energy and Mining’s mineral compliance officers to ensure the industry continues to perform at the high standards that are expected.
Maps and models of South Australian exploration projects, mines and quarries are being generated using camera-mounted drones to record real-time aerial imagery and video. When coupled with a satellite imagery processing system it allows precise measurements to be taken at these sites and for changes to be observed over time.
Additional benefits include the ability to identify unregistered activities that cannot be easily spotted from the ground and to be able to cover more ground safely, often over hazardous and challenging terrain.
Drone project development
In early 2018 the department purchased two Phantom 4 Pro drones and trained two compliance officers, certifying them as commercial drone pilots (Fig. 1). A series of ground control points, known as AeroPoints, and a 12-month licence for a software package, Propeller, that stitches together drone captured images into 2D maps or 3D models was also purchased (Fig. 2).
By placing AeroPoints over a mining or exploration operation prior to a flight, imagery captured is georeferenced and used to create a 2D orthomosaic that can be draped over a digital elevation model to create an accurate 3D model (Fig. 3).
Figure 3 Screenshot of 3D model generated using Propeller software, Hallett Cove.
Compliance officers receive the most benefit when a 3D model of a mining operation or exploration project is generated from the drone data. These 3D models are used to measure and calculate area and volume of exploration disturbance and monitor ongoing rehabilitation. For mining operations, models are used to measure pits, benches, stockpile volumes, haul roads, slope gradients and other mine features. By overlaying the tenement boundary, any area of disturbance outside the tenement can be clearly identified (Fig. 4).
Measuring the area of disturbance for mining or exploration operations in real time also allows for accurate and up-to-date rehabilitation liability calculations and royalty assessments.
Since February 2018 the department has conducted 39 flights over 27 exploration and mining projects, capturing over 6,800 photos and video files. Sites flown across South Australia range from large iron ore mines (Fig. 5) to small sand pits, from remote exploration drill sites to famous geological features, from Coober Pedy in the north to Mount Gambier in the south.
The department is looking to expand the use of drones to include the opal fields in Coober Pedy, Mintabie and Andamooka, and train more pilots in house. Drone footage and 3D models of geological features may also be used as an educational tool. The increasing use of drones across government also provides an opportunity for greater collaboration and the sharing of data.
– Ross Stevens and Daniel Orr, December 2018