EPSRC-funded project takes dual approach to clearing landmines

Clearing landmines from roads and fields can not only save lives and prevent life-changing injuries, it can also help communities economically, by giving them back access to agricultural land, as well as markets, food supplies, schools, and hospitals.

An anti-tank mine uncovered in the district of Govshatly, Hadrut Province, Nagorno Karabakh (Photo credit: ©Scout Tufankjian/HALO Trust)
An anti-tank mine uncovered in the district of Govshatly, Hadrut Province, Nagorno Karabakh (Photo credit: ©Scout Tufankjian/HALO Trust)

Removing anti-vehicle mines from roads can also reconnect people in neighbouring communities, and allow aid agencies and government bodies to reach areas that were previously cut-off.

But clearing landmines from roads and fields is often hampered by the slow speed of existing techniques used to detect and remove the devices. What’s more, the process is further complicated by the need to prioritise the order in which different areas are cleared, to provide the greatest benefit to local people in the shortest possible time.

Now researchers led by Dr Panagiotis Kosmas at Kings College London have launched an EPSRC-funded project to tackle both of these difficulties simultaneously. The researchers are developing a new sensor technology to detect landmines more quickly and reliably, alongside a method to consider cultural, political and socio-economic factors at national, district and community levels.

“The idea is to develop a de-mining strategy that interacts with the way that we are developing the technology,” said Kosmas.

The new detector is based on a technique known as quadrupole resonance, in which a radiofrequency (RF) pulse – or series of pulses – set at a particular frequency for the explosives of interest, are directed at the ground.

A planar RF antenna is placed close to the ground, in a similar way to a metal detector, and fed with a sequence of pulses.

If the material is present, it resonates – absorbing the radiofrequency pulses and retransmitting them, creating a signal that can be picked up by the same antenna that sent out the pulses. Kings College London’s QR research team, led by the project’s co-investigator Dr Jamie Barras, has applied this technique successfully in the past in applications ranging from the detection of explosives to medicines authentication.

A HALO deminer working in Sayad District, Sari Pul Province, Afghanistan (Photograph ©HALO Trust)
A HALO deminer working in Sayad District, Sari Pul Province, Afghanistan (Photograph ©HALO Trust)

“We know the frequency at which the explosive material is responsive, so based on the signal we receive we can say if something is there or not,” said Kosmas.

Unlike a metal detector, the sensor detects the explosive material contained within the mine, rather than features such as the casing or trigger, meaning there are few false alarms.

This can be particularly important with anti-vehicle mines, which contain very little metal but a lot of explosive, meaning they can be difficult to spot with conventional technologies such as metal detectors, and making them slow and expensive to clear.

The team will also be developing signal processing methods, to allow the detector to pick up signals in the field, even when there is interference or noise.

The researchers will initially investigate regions within Afghanistan, Somaliland and Angola, including studying economic activity within communities before and after de-mining operations, to determine the impact.

“So for example the economic data might suggest a specific rate at which we should carry out demining operations, which could be fed back into our technology development,” said Kosmas. “In principle, the more time we spend (de-mining), the more accurate the technique, but if there is a need to clear certain roads in a limited amount of time, then we may have to develop technology specifications that are related to what can be done in practice,” he said.

The researchers will work with humanitarian mine clearance organisation the Halo Trust, to test the technology in the field, and ensure it is fit for purpose. The project has received a £1m Global Challenges Research Fund (GCRF) grant from EPSRC.