With the advent of technologies reminiscent of science fiction films popping up all over the world, it comes as no surprise that some of the most astounding discoveries are being made right on our campus.
Yasamin Mostofi, associate professor in the Department of Electrical and Computer Engineering at UCSB, has designed a new technology that uses simple WiFi signals to allow unmanned vehicles to essentially “see” through walls.
In a hypothetical situation, a pair of robots arrives at an area that has been closed off with thick concrete walls, with no prior knowledge of what is behind them. As they move back and forth around the perimeter of the location, one robot transmits a WiFi signal while the other receives it. As the signal travels through the walled-in area, it interacts with the objects that lie within. Depending on the specific ways in which these signals interact with the objects, specific data, such as material properties and size, can be extracted.
“By designing paths more informative for imaging through walls, exploiting sparse signal processing and proper approximated wave modeling, we have shown that it is indeed possible for the two unmanned vehicles to image the entire area,” Mostofi said. “We can essentially see through walls, even thick concrete walls, based on only WIFi received power measurements.”
The potential applications of this technology in various fields of science and manufacturing, as well as to everyday life, are numerous. Rescuers in a search-and-rescue operation following a natural or manmade disaster, for example, could assess the disaster site before entering to avoid placing volunteers in a situation that could potentially be hazardous for humans.
“Furthermore, heating and cooling of a building can be better optimized based on learning the concentration of the people over the building,” Mostofi said. “Businesses can also benefit from counting the number of shoppers for better business planning.”
Simple though it may sound, interpreting the signals and building models to extract the data from the unmanned vehicles is no easy task. The inclusion of information from the fields of wireless communications, signal processing and robotics makes for complicated engineering work.
Solving the challenges that inevitably arise from such work requires a team of researchers who work alongside Mostofi to create novel solutions that allow the new technolwogy to continue moving forward, while always keeping sight of the fundamental limits of sensing with these signals.
“Radio frequency (RF) signals such as WiFi are everywhere these days. So it is natural to ask how much information they carry about us or about their surroundings,” Mostofi said. “Using these signals for sensing can have many other potential applications beyond imaging or occupancy estimation.”
And what about privacy issues as well as possible conflicts with the 4th Amendment?