The army moves over, digs in, hides in, and builds on the land. Success in these endeavors relies on information about landform, structure, composition (rock and soil types), nature of the surface (sticky, dusty, hard, soft, etc.), and an evaluation of obstacles, engineering materials, water sources, and potential sites for ambush, defilade, and cover and concealment. Geology looms large. For many world areas, such information is not in the databases nor on maps; yet it is sometimes needed on short notice. The information can be derived from image analysis, and available imagery covers most of the world. Examples of such applications include Thule Air Base, Icecap access routes, Project Sanguine, Southeast Asia trafficability studies, and Operations Desert Shield/Storm. The Remote Sensing Field Guide—Desert, developed by a joint effort between the U.S. Army Topographic Engineering Center (TEC) and the U.S. Geological Survey, was used extensively in Operations Desert Shield/Storm in support of military operations. These materials plus spectral reflectance data are being blended into a hypermedia terrain database to support interactive image analysis between army elements.