Ever been annoyed by static on an AM radio when people were moving around the room? Whether you knew it or not, you were confronting the fact that human beings absorb radio waves.
Now, researchers are turning the static problem to good use. They are exploiting the absorption ability to track people’s movements behind walls, according to ScienceNOW Daily News.
The studies could lead to new techniques for detecting people trapped in burning buildings and also for spotting burglars or enemy soldiers. The research also has potential for helping control lighting, heating and cooling systems as people enter and exit rooms.
The basic tool for the technology is an array of radio transceivers, devices like walkie-talkies that send and receive signals. Neal Patwari, a professor of electrical engineering at the University of Utah in Salt Lake City, led a team that developed software for displaying on a screen the approximate position of someone moving within a cordon of the transceivers.
They will report in an upcoming issue of Transactions on Mobile Computing that they built a prototype wireless network of pole-mounted, cell phone-sized transceivers. While one of the team members walked inside the array, the system could calculate his location with an accuracy of about three feet.
The researchers told ScienceNOW that the transceiver array can be set up and dismantled quickly, making it practical for use around a military encampment or a burning house. First, though, they have bugs to work out. For example, frequencies on the system can be jammed.
High-tech burglars, take heart.