 DARPA's WATCH-IT program developed robust low false
alarm density change detection software to detect vehicles and smaller targets under foliage, under camouflage and in urban clutter, and developed tomographic (3D) imaging to detect and identify targets that have not relocated.VHF/UHF SAR for building penetration, urban mapping and performing change detection of objects inside buildings.Terrain characterization technologies were also developed, including the abilities to rapidly generate bald-earth terrain height estimates and to classify terrain features from multipass VHF/UHF SAR imagery.