U.S. Army Aviation and Missile Command (AMCOM) has provided CIS with a large, well-documented database of air-to-ground FLIR data, courtesy Dr. Richard Sims. The data illustrate a wide variety of real-world effects which make detection and recognition challenging, including dust clouds and other obscurants, targets hiding behind trees, and "hard targets" which are difficult or impossible to see in a single frame, but become apparent from their motion when a sequence of frames are viewed.