Researchers at the University of Mississippi have come up with a faster, more efficient method for detecting landmines – millions of which pose a lethal threat to people in war-ravaged countries all over the world. This breakthrough, which uses lasers and acoustic vibration, has the potential to save thousands of lives a year.
Vyacheslav Aranchuk has been working on the Laser Multi-Beam Differential Interferometric Sensor (LAMBDIS), for more than a decade now. He received a patent for it back in 2019 while at the university's National Center for Physical Acoustics (NCPA), when he demonstrated how it can be mounted to a moving vehicle and quickly detect buried landmines up to 65 ft (~20 m) away.
The team's updated laser tech, presented at the Optica conference in Japan last month, forms a vibration map of the ground in near real-time to detect landmines. Rather than a set of 30 beams in a line like the previous iteration, it creates a 34 x 23 rectangular array of beams to cover a lot more area. And as before, this can also be operated from a moving vehicle at just under 10 mph (16 km/h). That speeds up the detection process further.
Aranchuk co-authored the report with NCPA colleague Boyang Zhang. They noted that their laser-acoustic detection method overcomes two challenges faced when using metal detectors: it can help find mines made of plastic, and can also avoid false positives triggered by other metallic objects in the soil.
Here's how it works. First, vibrations in the ground are created using airborne sound or seismic wave vibration excitation techniques. Next, the 2D-array laser multibeam sensor device measures the vibration response of the ground to acoustic or seismic stimuli in multiple points simultaneously over the area its laser matrix covers. These simultaneous measurements allow for quick vibration imaging, and enables it to detect buried objects, regardless of whether they're made of metal or plastic.
The updated LAMBDIS is quicker at obtaining vibration images of the ground surface than the previous linear array device Aranchuk had developed. The sensor is also less sensitive to its own motion, which is important for when it's mounted on a moving vehicle. By working quickly, avoiding false positives, and functioning from a distance, it keeps operators safe.
That could spell a safer future for people who live in 70 current and former war-torn countries around the world that are riddled with an estimated 110 million active landmines. These explosives caused 2,793 deaths globally in 2017, and that number tragically rose to 4,710 in 2022.
It could also accelerate humanitarian efforts at scale in these countries. Landmines can cost up to US$1,000 each to remove – which means that bringing down the cost, increasing efficiency, and ensuring higher safety for operators are critical to expanding the impact of such programs.
This design is the latest in the battle to make mine-affected regions safer to live in. Last year, we covered a novel magnetic resonance technique from scientists at Australia's CSIRO research institute, which transmitted pulsed radio frequency waves down into soil that would resonate with targeted crystalline compounds used in explosives to detect mines.
Another recent breakthrough from Safe Pro AI utilized off-the-shelf drones and machine learning applied to aerial imagery to spot a variety of mines scattered on the surface of agricultural land. By analyzing these images in fractions of a second, it speeds up the demining process and gives operators a better idea of what to look for as they clear the area.
As for LAMBDIS, Aranchuk is looking to research its capabilities further for different buried objects and in different soil conditions. It can also find use in other applications, like the assessment of bridges and other engineering structures, and nondestructive inspection of materials in the automotive and aerospace industries.
Source: University of Mississippi/Optica
