Which perimeter intrusion detection category translates return energy into range, speed, altitude, direction of travel and velocity?

• A. Microwave sensors
• B. Photo-Electric transceivers
• C. Ground based radar
• D. Buried and seismic sensors

Answer: (C)

Ground-based radar translates return energy into range, speed, altitude, and direction of travel by emitting radio waves and analyzing the echoes that come back. The time delay between transmission and the received echo gives the distance to a target (range). The Doppler shift of the returned signal reveals the target’s speed toward or away from the radar (radial velocity). With proper beam geometry and scanning, radar can also determine bearing (direction of travel) and, in systems that use elevation measurements or 3D scanning, altitude. This combination of range, velocity, and directional information is what sets ground-based radar apart for perimeter monitoring. Other sensor types in the list either detect presence or vibration (like beam interruptions or ground-shake signals) and do not provide this full set of kinematic measurements.