The Science and Technology Directorate (S&T) recently reported on field testing and commercialization of the cutting-edge Detection of Presence of Life technology. Now, S&T and the Massachusetts Institute of Technology Lincoln Laboratory (MIT LL) have concluded an additional round of testing of DePLife and similar scanning technologies, this time upgraded to withstand minor motions. This critical capability will soon make the work of law enforcement safer.
View Original "Law Enforcement Tech That Sees Through Walls" videoLast month, S&T completed the development of DePLife, a technology that leverages radar to “see” through walls, providing law enforcement with valuable intelligence and situational awareness in often precarious situations. Industry partner MaXentric Technologies LLC began sales this year to law enforcement agencies nationwide; already, several U.S. city and county agencies successfully tested and purchased DePLife. It has also been evaluated by the Federal Bureau of Investigations, which is now in the process of purchasing units.
Looking ahead to future generations of through-wall scanning, S&T is collaborating with MIT LL to upgrade DePLife and a similar technology, Analog Devices’ Tinyrad, to withstand minor movements via motion compensation algorithms. The goal is to expand the number of use cases and tactical scenarios. DepLife technologies can be deployed by law enforcement and other personnel during operations.
“Before the Through Walls Mobile Sensing project started, technologies that could detect the presence of life through walls had to be stationary, or perhaps leaning on a wall to the room of interest,” said S&T Program Manager Anthony Caracciolo. “But now, we are developing a tool that can withstand minor movements—hovering drone vibrations, light wind…even a responder’s breathing—while holding the device.”
Why is through-wall sensing technology critical for responder safety?
Using DePLife, officers can determine if a structure is occupied or not from a safe standoff distance using radar. The device can scan through interior sheetrock and outer walls of typical single-family homes. Last month, S&T and MIT LL tested prototypes at the lab’s facilities in the Boston area.
“With minor motion compensation—the next generation for these technologies—police officers, or even firefighters, can assess from a distance where the good and bad guys are at the scene,” said Caracciolo. “They won’t have to endanger themselves by having to place the detector in direct contact with a wall.”
One goal: a drone could quickly scan a house from the outside to see if any people are inside. This could be beneficial both for firefighters looking for people trapped in a burning building and for officers looking for hostages or perpetrators during an active shooter event.
S&T is leading the development of motion compensation algorithms using results of collected radar data. MIT LL used a hexapod, a programmable machine that can imitate various minor movements, to test the technologies’ performance against simulated minor movements. Engineers from MIT LL’s Autonomous Systems Development Facility recorded and collected various minor movements made by a person holding a radar or a hovering stationary drone with radar payload, and then programed the data into the hexapod, so it can recreate it.
In mid-April, S&T and MIT LL tested and demonstrated the performance of motion compensation algorithms in the Autonomous Systems Development Facility in Boston. They evaluated the viability of this next-generation through-walls technology on two platforms: an operator holding a handheld device and a drone. The team tested DePLife first on the hexapod and then on a handheld prototype, and then Tinyrad on a drone. The results were successful.
How does motion compensation of minor movements work?
When a person holds the radar, even if they are still, their hands make imperceptible movements, or their arms may swing the tiniest bit (by centimeters or millimeters). It is the same with a drone carrying the radar—it swings or vibrates while hovering. If the radar is moving, everything it detects also looks like it is moving. The algorithm uses stationary objects at the scene to estimate the radar’s movements. Algorithms can help determine what is indeed stationary and can make radar data corrections and compensate for the radar’s motions by extracting them to determine their type, and then estimate the platform position over time.
DePLife and Tinyrad were tested not only to detect people while in motion, but also for false positives, typically caused by static reflectors like furniture, refrigerators and fans. The team used corner reflectors—objects shaped like a pyramid, hourglass, and cube and wrapped in metal foil (as metal reflects radar waves)—to see if the technology will label them as humans or not. Although small, these objects are designed to reflect much of the radar energy that hits them and thus serve as a baseline to test the radar system.
“If there’s metal or furniture, you're going to get reflection back to the radar, and the radar can detect which one is actually stationary, not life, and which one is life,” said Caracciolo. “We must first make sure we are not identifying every reflection back as life. And we did that successfully.”
What’s ahead for Through-Wall Mobile Sensing?
Based on the performance results, S&T and MIT LL will refine next generation radar specifications throughout the next phase and finetune the minor motion compensation algorithms. After that, the team will upgrade the technologies with major motion compensation algorithms to cover movements like a drone flying around a building, an officer walking towards a building, or a ground robot entering a building.
All this to say, what S&T is trying to do now is determine what radar specifications and configuration would be able to achieve those ideal objectives.
“These efforts will increase the versatility and viability of a commercial-ready solution that meets federal, state, and local responder needs,” said Caracciolo.
For related media inquiries, please contact STMedia@hq.dhs.gov. For additional information about DePLife, listen to Good Chance You’re Going to Save Lives, an episode of S&T’s Technologically Speaking podcast with Anthony Caracciolo.