The Army is looking for mobile sensors that can detect tunnels. More specifically, the Army wants “bi-static frequency domain electromagnetic” — or BSFDEM — sensor systems, according to a request for information from the U.S. Technical Support Working Group.
“The goal is to provide a BSFDEM that can identify the position, extent and depth of cavities with both high probability of detection and localization accuracy that is able to be transported, assembled, operated and disassembled by a two-man team with all operators and components transported in a single vehicle,” said the RFI.
The system, which should be composed of commercial off-the-shelf components, will comprise a magnetic field transmitter, magnetic field sensors, highly accurate GPS and a processing unit.
“The transmitted field will interact with subsurface materials, both conductive and resistive, causing perturbations in the magnetic field(s) measured by the multiple magnetic field sensors,” according to the RFI.