Many of us have seen the videos taken by drones of mine and exploration properties presented at conferences in about the past two years by companies such as Carbine (CRB) etc, however in mid-June I saw the next stage, namely that of mapping being used by Alto Metals (AME) at their almost wholly owned Sandstone goldfield in WA.

Alto were using a Phantom 4 drone (4^th generation) developed within about 2 years, and costing ~$1600 to $1700 plus ~$70 for the software. The drone was being operated by Alto’s head of exploration, Dr Changshun Jia who said it took a couple of goes in a park near his house in Perth to master it. And I saw examples of what the drone is capable of in Alto’s head office in Perth.

Alto were using the drone shown in the figure for the first time in the field at their Vanguard Prospect, flying a 200m x 200m grid in 20 mins, taking a 40mb raw/jpeg picture every 20 secs at a drone speed of 2m/sec from a height of 60m with an 80% overlap of the images (the minimum recommended overlap is 75%, then at 5% increments to 95%). The resolution of the pictures depends on the height selected such as 40m, 60m, 80m or 100m, and the drone can fly at 20m/sec (~70km/hr) to its target area (determined from GPS satellites) apparently up to 10km away. The result after 20mins was 16gb of images stored on a micro-SD card.

Basically the drone is operated using a double-joystick controller and a mobile phone. The mobile phone displays the location of the drone and its progress in flying the designed grid (as shown in the figure). The drone is not capable of flying into any object or person due to the four sensors around it. If flown towards someone (Changshun flew it at himself) it simply stops and hovers. On completion of its task the drone returns to its launch position and hovers until the operator instructs it to land.

When downloaded and run through software the overlapped images enable a 3d model to be produced, and if required a colour-contoured height plan. Magnetics are a consideration for future models as they are currently apparently too heavy for the drone and need to be developed to become lighter and smaller. The resolution of the individual images as shown in the figure apart from showing every rock and twig etc, were able to be opened in Adobe Photoshop and with the shadow-highlight image adjustment, able to see down inside the old shafts.

The structural strike directions of the old stopes and shaft workings are easily identifiable (the long axis of a shaft being the strike of an orebody) in the images taken, and this together with the recent results reported by Alto in June 2017 at Vanguard have encouraged Alto to drill from two different  directions than the N/S and E/W applied historically by Troy (who did not mine at Vanguard as they apparently could not work out the geology). The greenish-grey rock chips are also identifiable and were checked as being dolerite.

The drone is also apparently capable of following and recording someone wearing some sort of device and hence providing a map of the area walked or passed.

Clearly drones are going to transform geological and mapping exploration.

Disclosure and Disclaimer : This article has been written by Keith Goode, the Managing Director of Eagle Research Advisory Pty Ltd, (an independent research company) who is a Financial Services Representative with Taylor Collison Ltd (AFSL 247083).

Figure. Phantom 4 Drone being used by Dr Changshun Jia at AME’s Prospects