Video surveillance activity has dramatically increased over the past few years. Earlier work dealt mostly with single stationary cameras, but the recent trend is toward active multicamera systems. Such systems offer several advantages over single camera systems - multiple overlapping views for obtaining 3D information and handling occlusions, multiple nonoverlapping cameras for covering wide areas, and active pan-tilt-zoom (PTZ) cameras for observing object details. To address these issues, we have developed a multicamera video surveillance approach, called distributed interactive video array. The DIVA framework provides multiple levels of semantically meaningful information ("situational" awareness) to match the needs of multiple remote observers. We have designed DIVA-based systems that can track and identify vehicles and people, monitor perimeters and bridges, and analyze activities. A new video surveillance approach employing a large-scale cluster of video sensors demonstrates the promise of multicamera arrays for homeland security.