Breakthrough technology may ease rescue, military missions
The terror of the early 21st century has unveiled a “new battlefield,” one in which new technology is needed to replace the inadequate equipment of before.
Scientists based at The University of Tennessee are currently designing a device that virtually removes the barrier of walls.
This research breakthrough could radically change circumstances for those engaged in many routine, yet deadly, operations regularly disclosed to newspaper readers through the daily headlines.
This device could mean a lot for the soldier apprehensive about entering an insecure dwelling, the police officer searching for the delinquent in a crowd carrying a gun or the rescue squad seeking to locate persons amidst the debris of a hurricane’s aftermath.
The research initiative, spearheaded by Aly Fathy, UT associate professor of electrical and computer engineering, involves constructing a device that would be capable of detecting and identifying people or objects situated behind a wall.
“The idea here is you identify your enemy from a distance rather than waiting for him to come to you,” Fathy said. “From a military perspective, now we are fighting a different war, an urban war.”
New technology could help with the unavoidable door-to-door searches typical of this new battlefield.
“For the military soldier, they can know the situation inside a room without having to enter,” said Yunqiang Yang, graduate student in electrical and computer engineering.
The device’s ability to prevent casualties is not limited solely to the defense sector. Rather, this project attracts researchers because of the diversity of constructive applications, spanning from terrorism to rescue operations.
“You can potentially find people trapped somewhere in disaster situations,” said Mohamed Mahfouz, assistant professor of biomedical engineering.
In addition to locating the physical presence of an individual, the device can be used to detect breathing or even DNA, Fathy said.
UWB Microwaves
Through-Wall Imaging and Surveillance, as the process is officially called, depends on a high resolution, Ultra Wideband radar.
UWB is radar that transmits very low power signals across a very wide range of frequencies, making it suitable for indoor or underground use.
“Ultra Wideband signal has a lot of advantages,” Yang said.
Yang, the graduate student working to construct the prototype device under Fathy’s supervision, said that UWB does not interfere with other communications, such as with cell phones.
The UWB also allows for high resolution imaging and is safe because of its low power level, Yang added.
The process works by transmitting UWB signals through the wall. The microwaves then hit the target and reflect back through the wall to a receiving antenna.
“We calculate the time difference of arrival between the transmitting signal and receiving signal,” Fathy said. “If you take different frames of the image, then you can know if the body is moving or not, which we call the Doppler Effect.”
The reflections are then processed using algorithms, or advanced mathematical procedures, to identify the objects through pattern matching and recognition.
“Once we get the images, which will come in a raw format, what we need to do is identify features,” Mahfouz said.
The pattern matching and recognition process distinguishes whether the objects are humans — possibly armed — animals, a moving target, etc.
“After we receive the data, we clean it and identify the objects in the scene,” Mahfouz said.
Building the image in this manner parallels other familiar processes, although differing in frequency and resolution.
“The process is very similar to seeing an unborn baby using ultrasound,” Fathy said.
Terahertz Microwaves
Terahertz radiation, a nearly 100 times higher frequency than UWB that also provides better resolution, is involved in a derivative project: the ability to see through materials such as clothing or plastic bags.
Tuan Vo-Dinh, the director of the Oak Ridge National Laboratory’s Center for Advanced Biomedical Photonics and an ORNL Corporate Fellow, has extended his use of lasers from environmental detection and medical diagnosis to collaborating on this subsurface sensing research.
“Spectroscopy is the science that involves interaction between light and matter,” Vo-Dinh said.
Vo-Dinh, who specializes in using lasers to detect toxins in the environment or cancer in human tissues, now uses spectroscopy to research the potential detection of plastic bags, knives or guns hidden on a person’s body.
Terahertz also has the potential to identify explosives or the chemical content of unknown compounds.
Vo-Dinh said he was excited about this collaborative work and its possible applications.
“We are almost neighbors,” he said, speaking of UT and ORNL. “There are a lot of things we can do together.”
With partners extending to California and Pennsylvania, the research program that is based in East Tennessee, welcomes and depends on collaboration. These alliances could yield results as quickly as in a couple of years.
“We are in the prototype phase,” Mahfouz said. “I would say probably within the next two years, something will materialize in this area.”
Rapid progress is evident from the two international workshops organized by UT in 2005 and the upcoming 2006 special journal issue dedicated to Through-Wall Imaging and Surveillance.
“Our Contribution”
When the Federal Communications Commission loosened regulations on UWB in 2002, researchers began to consider the radar’s other possible applications, Fathy said.
“I was involved in mine-detection and developing equipment to remove unidentified mines,” he said.
When the FCC opened UWB, Fathy recognized that this radar could locate weapons concealed within walls or armed rebels hidden behind walls.
“It came naturally as an extension of our research in locating these mines,” Fathy said. “Especially that UT is well-suited to build up this research with our excellent capabilities in image enhancement.”
Fathy credited Mongi Abidi, professor of electrical and computer engineering, for this excellence. Abidi is the director of the UT Imaging, Robotics, and Intelligent Systems Laboratory, whose efforts have contributed to research in Through-Wall Imaging and Surveillance.
Although some companies are developing similar products, the research program seeks to reduce the equipment’s complications and develop higher-quality pictures.
“They (other products) are very expensive, have very low resolution, and require sophisticated operators to identify objects on the scene,” Fathy said. “Our contribution here at UT is to make them portable, affordable, so soldiers and law enforcement officers can use it and be able to easily understand the images and the patterns.”
The UT program is fully endorsed by the UT-ORNL Center for Homeland Security and Counterproliferation and by Rep. John Duncan, R-Tenn., Fathy said.
Source: The UT Daily Beacon.