Lasers make it easier to find buried landmines

Scientists in the The US has developed technology that can detect landmines from long distances and with high accuracy, potentially reducing the risk of mine clearance from current and former conflict areas. The technology, known as Laser Multibeam Differential Interferometry Sensor, or Lambdis, works by aiming lasers at the ground to detect suspected threats.

There are currently more than 110 million landmines buried worldwide, and in 2023, mines killed or injured 5,700 people, with 84 percent of the victims being civilians – half of whom were children. According to the United Nations, landmines threaten human lives in more than 70 countries.

A mine can be made for as little as $3, but removing a mine can cost up to $1,000. Clearing landmines typically requires people to find them using portable metal detectors. This is dangerous, time-consuming and almost ineffective when searching for plastic mines.

In response, US researchers developed indirect landmine detection technology that could detect both metal and plastic mines. Lambdis sends a vibration into the ground and simultaneously scans the area with a laser beam. Materials in the ground vibrate at different frequencies, as does the ground itself, and these differences are detected by the laser as it is reflected back to its emitter. The Lambdis system then creates an image that visualizes these vibrations and their locations in different colors, creating a map of the things buried in the ground.

The technology was developed by a team led by Vyacheslav Aranchuk, a laser sensing specialist at the University of Mississippi. Importantly, it can detect mines from a distance and can be mounted on a moving vehicle to make scanning large areas easier.

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

The researchers are further developing the system. An earlier version of Lambdis sent out 30 laser beams in a line, but the latest version sends out beams in a 34 x 23 matrix, allowing vibrations to be visualized over a larger area.

Traditional metal detectors used for demining respond to any metal object, so it is not uncommon for them to incorrectly detect things other than landmines. And an alternative solution to demining, underground radar, which sends high-frequency electromagnetic waves into the ground, has the disadvantage that it can be easily influenced by the condition of the ground. In comparison, Lambdis produces fewer false alarms.

According to the research team, the technology can be used not only for landmine detection, but also for assessing structures such as bridges for structural integrity or damage. In the future, it could be used to analyze products in the automotive and aviation industries or even in medical imaging. Next, the team plans to evaluate Lambdis’ performance in different ground conditions and when searching for other types of buried objects.

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