The Portable Reconfigurable Line Sensor (PRLS) is a bistatic, pulsed-Doppler, microwave intrusion detection system developed at Sandia National Laboratories for the U.S. Air Force. The PRLS is rapidly and easily deployed, and can detect intruders ranging from a slow creeping intruder to a high speed vehicle. The system has a sharply defined detection zone and will not falsely alarm on nearby traffic. Unlike most microwave sensors, the PRLS requires no alignment or calibration. The PRLS's unique ellipsoidal detection zone eliminates the need for an offset distance to achieve total detection coverage. The sensors themselves are inside their own detection zone and are therefore self-protecting. Its portability, battery operation, ease of setup, and rf alarm reporting capability make it an excellent choice for perimeter, portal, and gap-filler applications in the important new field of rapidly-deployable sensor systems.