Eggheads at MIT are getting better and better at using Wi-Fi signals to see through walls, capturing motion accurate to within a few centimetres.
Using the same signals sent out by your wireless router, the team built a device it has called RF-Capture, and placed it behind an ordinary lab building wall. It was able to pick up coarse images of individuals on the other side of the wall by analyzing reflected radio waves, which they then converted into a heat-map-style graphic.
Interestingly, the group then worked on the system to track motion. The combination of many different pictures that in themselves are not very detailed helps build up an accurate picture of what – and who – is on the other side of the wall.
READ MORE: http://www.theregister.co.uk/2015/10/28/mit_wifi_see_through_walls/