Improvised explosive devices (IEDs) are
the most dangerous risks that the militray forces are
currently facing and account for more than 50 percent of
daily attacks. Detection of such buried IED is a very
challenging task, because the detection task should be
performed from a considerable standoff distance. Rapid
survey speed is also required.
The magneto-telluric field is created from interaction of
natural sources such as the earth’s magnetic field and solar
winds. This field is naturally varying and induces electric
currents (or telluric currents) under the Earth’s surface in
the frequency range of sub-hertz to 10 kHz. Any
discontinuity in the soil’s conductivity due to the presence
of a buried conducting object will create current gradients
which can be measured on the surface. Our group conducted
numerical simulation and found that a highly conducting
object creates detectable magneto-telluric gradient in the
range 3 – 7 p Tesla . The superconducting quantum
interference device (SQUID) sensor, well known for providing
sufficient sensitivity (hundreds of f Tesla range) to
measure such small magneto-telluric gradient, has been
applied to build our prototype IED detection platform. Fig.
1a shows the 8-channel SQUID available in our laboratory. In
this project, we examine the use of high temperature (Liquid
Nitrogen) SQUID sensor to detect disturbance of earth’s
magneto telluric field due to the presence of metallic
objects. We conduct various scenarios of field (outdoor)
experiments to detect metallic targets buried in different
type of soil conditions using prototype SQUID system. Fig.
1b shows encouraging results from field tests in the
volcanic soil in Hawaii. Limitation and detection
performance of the SQUID are being evaluated based on the
Deliverables & milestones
- Numerical study of the magneto-telluric field at the
presence of buried metallic objects.
- Analyze the SQUID sensor performance at the outdoor
- Development of a prototype IED detection platform
using SQUID sensor.
- Experimental measurements using the developed
- Evaluate detection performance of the developed
system and provide the optimal configuration.