DARPA's 1.8 Gigapixel Drone Camera

DARPA's 1.8 Gigapixel Drone Camera Could See You Waving At It From 15,000 Feet

One thing to note is that a drone can just hang out at 15,000 feet over a small city-sized area (roughly, half of Manhattan) and provide video surveillance of the whole thing. The other thing to note is that they are running machine vision on the moving objects, which means they are generating structured data out of the video, not just displaying the pictures.