Lasers Make It Easy to Find Landmines

scientists at The US has developed technology that can detect landmines from afar and with high accuracy, which can reduce the risk of demining in current and former conflict zones. Known as the Laser Multibeam Differential Interferometry Sensor, or Lambdis, the technology works by shining lasers onto the ground to reveal suspicious threats.

There are currently more than 110 million landmines buried around the world, and in 2023, landmines killed or injured 5,700 people, with civilians accounting for 84 percent of casualties—half of them children. According to the United Nations, landmines threaten life in more than 70 countries.

A mine can be made for as little as $3, but removing it can cost up to $1,000. Landmine clearance often relies on people finding them with hand-held tools, which are dangerous, time-consuming, and nearly ineffective when hunting for plastic mines.

As a result, US researchers are developing indirect landmine detection technology, which can detect both metal and plastic mines. Lambdis works by sending vibrations into the ground while simultaneously scanning the area with a laser beam. Objects on the ground will vibrate at different frequencies, as will the ground itself, and these differences are picked up by the laser when it is reflected back to its output device. The Lambdis system then produces an image that visualizes these vibrations and their locations in different colors—creating a map of the material buried in the ground.

The technology was developed by a team led by Vyacheslav Aranchuk, an expert in laser sensing at the University of Mississippi. Importantly, it can detect mines from a distance, and can be mounted on a mobile vehicle to help scan large areas.

“The number of landmines will continue to increase as long as the conflict continues. This technology will be useful not only for military use in ongoing conflicts, but also for humanitarian efforts after the end of conflicts,” said Aranchuk.

Researchers continue to develop the system. The previous version of Lambdis emitted 30 laser beams in a row, but the latest version emits the beams in a 34 x 23 matrix, allowing it to visualize vibrations over a wide area.

Conventional metal detectors used for demining react to any metal object, so it is rare to accidentally detect objects other than landmines. And another demining solution, underground radar, which emits high-frequency electromagnetic waves into the earth, has the disadvantage of being easily affected by soil conditions. Lambdis, by comparison, produces fewer lies.

According to the research team, the technology can be used not only to detect landmines, but also to check civil engineering structures such as bridges for structural integrity or damage. In the future it may be used to analyze products in the automotive and aerospace industries, or even in medical imaging. Next, the team plans to test the performance of Lambdis in different soil conditions and when hunting other types of buried objects.

This story appeared on WIRED Japan and was translated from Japanese.