Through-Wall 3D Motion Tracking Using Specialized Radio Waves

Earlier this year, MIT professor Dina Katabi and graduate student Fadel Adib unveiled WiVi, a system that detects people through walls and can track the direction of their movement using WiFi signals. Based on this work, Katabi and Adib have collaborated with other researchers on a new technology they call WiTrack. In comparison to WiVi, WiTrack has higher accuracy and can track both two-dimensional and three-dimensional movement using specialized radio waves, as opposed to WiFi signals. WiTrack uses multiple antennas - one for transmitting signals and three for receiving. The system then builds a geometric model of the user's location by transmitting signals between the antennas and using the reflections off a person's body to estimate the distance between the antennas and the user. WiTrack can pinpoint a person's 3D location to within 10 to 20 centimeters - about the width of an adult hand. The technology has applications in gaming, as well as fall detection among the elderly.