Think of a blimp and what comes to mind is that slow-moving billboard in the sky, floating overhead at a sporting event. But soon these airborne dinosaurs could be transformed from lowly airship to high-tech floating surveillance system.
That's the aim of military researchers at the U.S. Navy's Office of Naval Research in Arlington, Va., which is now working with engineers at Honolulu-based Science and Technology International, or STI, on a blimp known as the Skyship 600.
The Skyship 600, built by Global Skyship Industries, is outwardly no different from the airships seen at sporting events or large public venues. But what sets the 200-foot-long craft apart is the suite of sophisticated electronics called the Littoral Airborne Sensor Hyperspectral, or LASH.
The equipment, installed in the craft's gondola, is a set of sophisticated digital cameras with highly sensitive color detectors connected to a computer with specially developed software algorithms.
The cameras are designed to capture a wide variety of the light spectrum — ranging from the invisible infrared and ultraviolet to colors visible to the human eye — all reflected from objects below.
Greg Plumb, an STI researcher working on the project, says LASH works on the principle that all objects reflect light differently, creating unique light patterns — especially in the invisible infrared and ultraviolet parts of the spectrum.
The LASH cameras capture those signals and sends them to the computer for analyzing.The visual patterns from all the sensors are compared so that abnormal signals stand out.
"Camouflage netting might looks like the green leaves of the nearby forest to the naked eye," explains Plumb. "But there are minute spectral differences that make it stick out from the natural foliage. It just doesn't reflect light in the same way."
Once the computer has determined such a spectral anomaly exists in the images it's capturing, the system alerts an on-board operator to take a closer look. The information could also be instantly shared with command centers on land using a wireless data network.
Originally developed to detect submarines hidden in the littoral or coastal areas, the LASH system has already been tested and approved for use in other aircraft such as Navy helicopters and planes.
But by adding a LASH system to a blimp, Plumb and other researchers say the military would have an ideal tool for a variety of surveillance duties, such as hunting for terrorist divers, underwater mines in harbors, or even search-and-rescue.
Steve Huett, a program manager of the project with Office of Naval Research, says the blimps themselves haven't changed much from those used by the Navy during World War II. But they have their advantages.
"Helicopters shakes and planes have to keep moving in forward motion," explains Huett. "But the advantages of a blimp are that the g-loadings [on the electronic equipment] are not harsh and it goes slow."
In other words, airships provide a steady platform for spying. And unlike planes or even unmanned spy planes, can loiter and provide an uninterrupted view of an area for up to 12 hours a flight.
Some are skeptical military surveillance blimps will take off in a really big way.