Imagine enough landmines buried underground to circle the Earth twice. Identifying and removing these explosives is expensive and takes a long time. Thankfully, new research from the University of Mississippi could offer a solution.
Vyacheslav Aranchuk, a principal scientist at the National Center for Physical Acoustics, presented his groundbreaking research on laser multibeam vibration sensor technology at the Optica Laser Congress and Exhibition in Japan. This technology can detect landmines much faster than traditional methods.
“There are millions of landmines worldwide, and sadly, more are being added every day due to ongoing conflicts,” Aranchuk explained. “This technology has applications in both military situations during conflicts and humanitarian efforts after the fighting stops.”
The impact of landmines is devastating. Over 110 million active landmines exist globally, and in 2022 alone, they or other unexploded ordnance injured or killed 4,710 people. The majority of these victims were civilians, with children making up half of the civilian casualties. Seventy countries still live with the constant threat of landmines, including former and current war zones.
While landmines are cheap to make, costing as little as $3 each, identifying and removing them can cost up to $1,000 per mine. Current detection methods mainly rely on handheld metal detectors, which are slow, dangerous, and ineffective against plastic landmines.
Aranchuk’s team developed a laser vibration sensor in 2019 that could detect buried objects from a moving vehicle using 30 laser beams arranged in a line. Their latest technology can create a vibration map of the ground in less than a second, using a 34 x 23 matrix of beams.
“Many modern landmines are made of plastic, making them difficult to detect with traditional metal-detecting methods,” Aranchuk said. “That’s why the NCPA developed this innovative detection method.”
Like the 2019 technology, Aranchuk’s laser multi-beam differential interferometric sensor, or LAMBDIS, can be used from a moving vehicle, significantly speeding up landmine detection. Boyang Zhang, a former postdoctoral researcher at the NCPA, co-authored the report.
“Metal detectors often produce false positives by detecting any metal object, and ground-penetrating radar can be hindered by soil conditions or materials,” Zhang explained. “In contrast, laser-acoustic detection uses a combination of laser and acoustic sensing, allowing it to detect landmines from a distance with greater accuracy. It reduces false positives and enhances safety by keeping operators further from the detection zone.”
To find buried objects, the researchers create ground vibrations and then direct a two-dimensional array of laser beams at the ground. The vibrations cause slight changes in the frequency of the reflected laser light, which are used to create a vibration image of the area. A buried landmine vibrates differently than the surrounding soil, appearing as a red blob in the image.
“The technology works by analyzing the interference of light,” Aranchuk said. “We send beams to the ground, and the interference of light scattered back from different points on the ground produces signals that, when processed, reveal the vibration magnitude at each point on the ground surface.”
While the technology is primarily designed for landmine detection, its applications extend far beyond. “LAMBDIS technology can be adapted for various purposes, such as assessing bridges and other structures, vibration testing, non-destructive inspection of materials in industries like automotive and aerospace, and even biomedical applications,” Aranchuk stated.
Aranchuk’s next research step focuses on evaluating LAMBDIS’s performance for different buried objects and in diverse soil conditions.
This research was supported by the U.S. Department of the Navy’s Office of Naval Research.
