During the days of the Cold War, intelligence analysts tracked Soviet missile deployments and launches, as well as mass maneuvers, using the technological wonders of change detection, the arcane art of looking at satellite and U-2 photos to see what had moved where and how fast they were moving.
Analysts watched shadows, pondered piles of earth and eyed gantries and missiles as the Cold War waxed and waned. While resolutions improved and the US launched bus-sized radar satellites to better track what was happening, some goals remained unattainable. One of those was near real-time analysis of ground forces in almost any weather. Clouds render most electro-optical satellites largely useless and radar satellites are so rare that much of the earth goes unseen by them most of the time.
Northrop Grumman has worked on an a promising approach, using L-band synthetic aperture radar and a great deal of software to come up with a radar system that could offer analysts more detailed and up-to-date information. It was displayed at the Geoint conference in San Antonio.
It can cover an enormous 6,000 square miles an hour and provide impressive detail, presented in an easily interpreted form.