Millimeter-wave TV camera sees through smoke, fog and even walls
By Darren Quick
June 15, 2010
The Science & Technology Research Laboratory (STRL) of Japan’s national public broadcaster, NHK, has developed a “millimeter-wave TV camera” that operates under the same principle as radar, taking images using radio waves instead of visible light. The technology allows objects hidden behind obstacles such as smoke, fog or even plywood to be captured as live, moving images.
The system emits millimeter waves in the 60-GHz band which bounce off the subjects and are captured by a receiver beam that scans up/down and left/right at a speed of 2.3 Hz to produce a 2D image. Because the system is sending out the waves it can selectively ignore information of an obscuring foreground object (such as a wall) based on the time it takes the waves to reflect back to the antenna, instead producing a picture based on the waves bouncing off a hidden object that take longer to reflect back.
At the moment the resultant image is more grainy mess than high resolution, but the shape and movement of a person – or in the case of the NHK demonstration, a mannequin – can easily be made out, as this video from DigInfo shows. The low resolution suggests the technology would be better suited for rescue applications rather than NHK’s original intentions for the technology of TV reports during disasters. The technology also has obvious applications for security and surveillance.
NHK demonstrated its millimeter-wave TV camera technology at a recent STRL Open House. The company plans to pursue research into the technology with the aim of increasing the image quality and frame frequency.