University of Bristol Drone

Bristol team adapt UAV and camera technology to hunt mines

Unmanned aerial vehicles (UAVs, also known as ‘drones’) have huge potential for use in demining, so it is not surprising that Find A Better Way funds a project at the University of Bristol called ‘Project UAVs for Landmine Detection.’ What may surprise many, however, is that project is not designing a new type of drone. Instead it is adapting existing technology, especially infrared and hyperspectral cameras, to turn drones into cost-effective tools to speed up the demining process.

“It’s possible to get a perfectly good drone for a few thousand pounds these days,” explains Dr Day. “Designing our own drone would not be a good use of time and money. Instead we concentrate on adapting existing technology so that deminers can benefit from it as soon as possible.”

Much of this work focuses on adapting cameras that can identify potential explosive remnants of war (ERW) while mounted on a drone. This could help deminers identify risks more quickly, but most importantly it could identify an area of land as free of ERWs, a process known as ‘area reduction.’

Dr Day explains, “Mines can damage an economy as well as individuals individuals because of all of the productive land that is taken out of use until it can be declared safe. Speeding up that process would have huge benefits for post-conflict societies.”

The team, which also includes researcher and certified UAV pilot John Fardoulis, has developed a prototype system that uses an adapted camera system to take infrared images of suspected minefields.

‘To the human eye it can be difficult to spot a green plastic landmine on green vegetation, but when viewed through the infrared spectrum they appear different colours,’ Fardoulis said. ‘A drone flying overhead can spot evidence of cluster munitions, landmines or ERW on the surface, which can help deminers better prepare in dealing with such threats.’

Even bigger advantages are expected when drones begin to use hyperspectral cameras, which collect information from an even wider section of the electromagnetic spectrum. Plants are known to absorb contaminants from buried explosives over time. Contaminated vegetation may appear different on hyperspectral images than unaffected plants nearby, thereby revealing explosive material buried below.

Two of the researchers from the the University of Zagreb, Prof. Milan Bajic  and Dr Tamara Ivelju, have conducted preliminary tests of this idea at the Benkovac landmine testing facility in Croatia. They’ve found that plants growing above landmines can have a different appearance when seen with a hyperspectral camera.

Besides the infrared and hyperspectral detection techniques, the Bristol team are also looking for ways to incorporate their drone expertise into the work of other Find A Better Way funded projects.

Bristol Drone ERW display
An infrared image of a field taken by Bristol’s UAV. Man-made test objects show up as white dots.

“Because drones fly above the surface they are an obvious choice for safely deploying sensors to a minefield,” explained Dr Day. “We have spoken with the Project SEMIS team at the University of Manchester about integrating their sensors onto a drone, but it is not nearly as easy as it would seem at first.

“Most mine-detecting sensors need to be very close to the ground and to know their exact position relative to the ground at all times. Flying a drone a few metres off the ground from a safe distance is a real challenge, even more so if there are trees or thick foliage in the area.”

Speaking of the Bristol project, Find A Better Way CEO Lou McGrath was enthusiastic about the work the team is doing.

‘Using drones to reduce the size of areas that need demining may sound like small advance, but it could have huge benefits for the people living in former conflict zones. The University of Bristol team are doing a great job expanding the range of tools available for demining. They are not trying to reinvent the wheel; they are simply trying to put the benefits of current technology into the hands of deminers as soon as possible.’