I’ve been reading about the explosive booby traps in Afghanistan which these days are called IEDs. Detecting them often relies on spotting minute changes in a regularly patrolled section of territory.
Today’s invention is a reuse of the idea behind IOTD #46:
“…to detect the almost imperceptible differences between two ‘alike’ images, all you have to do is ‘fuse’ these’ by crossing one’s eyes a little and visually superimposing them. Areas of disparity then all stand out simultaneously as twinkling regions.”
A troop would record a number of movies of their patrol using a robot cart carrying several cameras and following a preprogrammed path.
The next day this would be repeated with one or two soldiers viewing today’s and yesterday’s scenes through a stereoscope. Any disparities would be immediately visible and highlight possible hidden bombs.