It has been a year since Colombia’s guerrilla forces (best known as FARC) agreed with the government to remove the estimated 200,000 land mines that remain hidden in the jungle in the aftermath of the country’s 50+ year civil conflict. However, so far the cleanup has been slow, and it’s clear that the current techniques are not adequate. So, a team of German researchers is developing advanced radar technology to help locate the mines.
All mines must be found, because it is a matter of humanitarian mine clearance. Consequently, our project will not produce any patents.
Currently, the Colombian military is using metal detectors, which doesn’t accomplish much, since the homemade mines—a.k.a improvised explosive devices (IEDs)—don’t include much metal, and can’t be distinguished from other random litter. “Only one in 2,000 found objects is a mine,” says Dr. Christoph Baer, who is working on a solution. He is part of a team of engineers from Ruhr-Universität Bochum and Technical University Ilmenau. The two German universities are collaborating with Colombian partners to develop a handheld radar system for locating the land mines.
They are designing a custom system that is similar to Ground Penetrating Radar technology that is used by archaeologists. It is made of three main components: an antenna, a radar detector, and a positioning system. The German engineers built their own antenna that operates from 500 megahertz to 4 gigahertz. They avoided metal elements as much as possible, in order to minimize unintended signal reflection and to make the system light enough for a handheld design.
Students at the German universities built their own (non-explosive) mines from everyday objects, so that the engineers could test the system. They intentionally let the students each come up with their own designs in order to mimic the randomness of FARC’s land mines.
Then they created computer models and simulated the mines’ radar signals in order to find the radar cross section that could be used to differentiate a mine from random objects such as a stone or screws. Looking ahead, the researchers plan to improve the system’s optics so that a person holding the radar device will be able to see images in real time. They will develop signal processing to remove interferences caused by layers of earth from the images, focus on point objects, and compare the properties of their signals with known radar cross sections of different mine types or other objects. The researchers are now seeking funding to support the estimated two to three years it will take to develop a prototype.