Guided radar technology creates a detection zone between a pair of ported coaxial cables that have been constructed to leak electromagnetic energy at a low VHF frequency. Pairs of such cables are buried around the protected perimeter, and the electromagnetic coupling between the cables produces a detection zone or radar fence. Interaction with local soil patterns and other mediums forms a sensitivity profile unique to each pair of perimeter cables. A digital copy of this profile is stored in a computer, which monitors changes. A patented application of digital processing to closed circuit television (CCTV), known as DAVID (digital automatic video intrusion detector), produces an effective human-machine interface. This interface equips the CCTV system to monitor automatically video images from the surveillance zone. It detects movements that require human attention and furnishes graphic enhancements to help a guard assess the nature of the intrusion. Modem digital signal processing can analyze the size, shape, and movement patterns of the video change. It can scan multiple cameras and point to the exact location in the picture where a potential intrusion has occurred.