Out on the battlefield, the radar shows you something’s there. But what is it? You should know before you shoot.
Answering the question, what is it, is where the Submillimeter-wave Technology Lab (STL) makes itself useful - so useful that the U.S. Department of Defense has appropriated $27 million to fund its research over the next five years.
“We and our government sponsors are the only research program that uses terahertz frequency measurement systems to collect real-world radar signature data,” says Dr. Robert Giles, STL director and professor of physics, in explaining the lab’s unique position.
The STL is a member of the Expert Radar Signature Solutions consortium, developed by the Army’s National Ground Intelligence Center. Radar signatures collected at STL are high quality and low cost. But “low cost” is a relative term when dealing with sophisticated equipment and extraordinary precision.
For 25 years under the direction of Dr. Jerry Waldman, now science adviser to the STL, researchers have engineered and constructed scale versions of all types of radar systems and models of actual targets, then measured and analyzed the radar scattering to produce the characterizing signatures of ships, tanks and other tactical vehicles. The submillimeter, or terahertz, wave is to the scale models as radar is to the real target in battlefield conditions.
The model fabrication operation, for example, converts tactical target photos and computer images into high fidelity scale models - with scaled welds, bolt heads, track links, lug nuts, rust and battle damage, and non-metallic parts like rubber pads, fiberglass and canvas.
Similarly, terrain affects a vehicle's radar signature. STL has designed and made more than two dozen ground types that model the variety of reflections produced by desert, soil, asphalt, concrete and other terrains. New research involves techniques to model complex terrain including roughness, rocks, trees, vegetation, roots and grass, as well as changes in moisture. In addition, the clutter of objects found in real operations - troop packs, ammunition storage crates, fuel containers, damaged vehicles, etc. - can be modeled.
At the heart of the facility, a 20-member research team, with the aid of several dozen graduate and undergraduate students, builds and maintains a variety of high-performance solid-state and laser-based measurement systems to generate the terahertz frequency radiation.
Besides its work for the Army, the lab has used its unique capabilities to fulfill radar measurement requests from agencies in all branches of the Department of Defense. The STL also conducts research for defense-related laboratories and companies, including MIT Lincoln Laboratory, Boeing Lockheed & Martin, and Raytheon.