Laser beams emitted towards the ground detect landmines with great precision

There are currently more than 110 million landmines buried in the world. 4,710 people were injured or will die from landmines in 2022. More than 85% of them were civilians. Half were children. According to a United Nations reporteveryday life is threatened by landmines in more than 70 countries, many of which are current or historical conflict zones.

Uninstallation is more expensive

Cheap landmines can be made for as little as $3 each, according to the Alliance for Change, the military arm of the North Atlantic Treaty Organization (NATO). However, removing them can cost up to $1,000 each. Additionally, most rely on portable metal detectors, which are dangerous, time-consuming, and largely ineffective at detecting plastic mines.

Now there is good news. US researchers have developed technology that can detect buried objects, including landmines, by analyzing the frequency of laser beams reflected from the ground. “The number of landmines will continue to increase as conflicts continue, and this technology could be useful not only for military use in ongoing conflicts, but also for post-conflict humanitarian efforts,” said lead researcher at the University of Mississippi, Vyacheslav Aranchuk.

Identify landmines by visualizing vibrations

He laser multibeam differential interferometric sensor (LAMBDIS), developed by Alanchuk and his team in 2019, is a revolutionary invention that can detect buried objects from a safe distance while moving in a vehicle. LAMBDIS works by vibrating the earth’s surface and emitting a laser beam at the same time. By analyzing slight changes in the frequency of the laser beam reflected by the vibration using acoustic detection, it creates an image that visualizes the vibrations in a way that can be distinguished by color. Buried landmines appear as red dots on images because the frequency of the laser beam is different from that of the surrounding soil due to vibrations.

Now researchers have managed to improve the conventional LAMBDIS, which fires 30 laser beams in a line, to make the speed of landmine detection even more effective. By irradiating laser beams in a 34 x 23 array, the new LAMBDIS can now generate images that visualize vibrations over a wider range.

Since metal detectors detect all types of metal objects, it is not uncommon for objects other than landmines to be mistakenly detected. Furthermore, underground radar exploration, which emits high-frequency electromagnetic waves into the ground, has the disadvantage of being susceptible to the conditions of the ground itself. In contrast, LAMBDIS, which combines laser and acoustic detection, can detect landmines with high precision even from a long distance, reducing false detections and ensuring worker safety.

According to the research team, LAMBDIS can be used not only for the detection of landmines, but also for the evaluation of civil engineering structures such as bridges, vibration testing in the automotive and aerospace industries, and non-destructive testing (which detects the presence , the size and shape of undestroyed scratches). It can also be applied to the medical field. It is expected that this technology can easily visualize vibration phenomena even in conditions difficult to handle with conventional methods. In the future, scientists plan to evaluate the performance of LAMBDIS in different soil conditions and buried objects.

(Edited by Daisuke Takimoto)

Article originally published in WIRED Japan. Adapted by Mauricio Serfatty Godoy.