Could drones help hunt the deadly traps?

Ulm / DPA
Landmines are notoriously difficult to clear away. Deminers have to bravely probe the ground, putting themselves in mortal danger. Explosives dogs are expensive to train. And if caterpillar-tracked vehicles are used to detonate the mines, they ruin the whole area in the process.
Researchers are now investigating whether drones could be used to hunt for the deadly traps. Ulm University in Germany and the Northwestern Switzerland University of Applied Sciences and Arts have launched a joint project called FindMine.
They hope to develop a drone that will fly over mined areas, scanning the ground for the explosive devices using radar sensors. The drone’s elevated view makes it potentially both cost effective and safer.
Drones allow you to scan much larger areas, says Professor Christian Waldschmidt, head of the Institute of Microwave Engineering at Ulm University. The number of people who fell victim to landmines worldwide rose drastically from 2014-15.
At least 6,461 people were killed or injured by landmines in 2015, according to report Landmine Monitor 2016. That’s around 75 per cent more than in 2014. According to the data, 78 per cent of the victims were civilians, of which 38 per cent were children.
During the three-year project, the Swiss contingent will work on the drone, while the group in Germany will concentrate on the radar sensor to detect the mines in the ground.
This is no easy undertaking – the sensors cannot be too heavy and the drones sway in flight.
The drone is supposed to hover on autopilot at a height of 1.5 metres and shoot electromagnetic waves 20 centimetres into the ground along its flight path. The signal is reflected in the ground, and then a series of recordings is used to generate a high-definition image. A mine has a particular shape and is filled with the explosive TNT, so it should show up very bright on the picture.
After the drone’s flypast, deminers use the map to locate and dig up the explosive traps.
One major problem for the researchers is that the drone is not very precise in its movements.
“It’s an enormous challenge,” says Waldschmidt. “Nobody has done this yet.” They test the sensors in a special anechoic chamber. This is a room insulated with foam pyramids containing carbon, which absorb all the unwanted rays. Necessity has made the researchers in Germany inventive. In the absence of real mines, they recreate the explosive devices using cream tins filled with silicone.
“We want to recreate the electrical characteristics of the mine,” says doctoral student Markus Schartel.
He says the mine-hunting drone is especially suited to use in arid regions.
“Iraq, Iran, Syria, the former Yugoslavia – there are still an incredible number of mined areas,” Waldschmidt says. The drone struggles to penetrate damp ground, however, which could prove a major hitch.
The first tests are completed, so now the drone and radar technology have to be calibrated to each other.
Towards the end of the three-year project, the researchers plan to test the drone in real mined areas such as Sarajevo and Cambodia.
Christian Waldschmidt says they aren’t aiming for a revolution.
“But we do want to greatly speed up detection.”