U.S. Air Force Fact Sheet
PAVE PAWS RADAR SYSTEM

Mission
PAVE PAWS is an Air Force Space Command radar system operated by three 21st Space Wing squadrons for missile warning and space surveillance. PAVE PAWS radars are located at Cape Cod Air Force Station, Mass., Beale AFB, Calif., and Clear AFS, Alaska.
PAVE is an Air Force program name, while PAWS stands for Phased Array Warning System. The radar is used primarily to detect and track sea-launched (SLMB) and intercontinental ballistic missiles (ICBMs).
The system also has a secondary mission of Earth-orbiting satellite detection and tracking. Information received from the PAVE PAWS radar systems pertaining to SLBM/ICBM and satellite detection is forwarded to the U.S. Strategic Command's Missile Warning and Space Control Centers at Cheyenne Mountain Air Station Colo. Data is also sent to the National Military Command Center and the U.S. Strategic Command.

Features
The unique aspect of this radar is the phased array antenna technology. This system differs from a mechanical radar, which must by physically aimed at an object in space to track and observe it. The phased array antenna is a fixed position and is part of the exterior building wall. Phased array antenna aiming, or beam steering, is done rapidly by electronically controlling the timing, or phase, of the incoming and outgoing signals.
Controlling the phase through the many segments of the antenna system allows the beam to be quickly projected in different directions. This greatly reduces the time necessary to change the beam direction from one point to another, allowing almost simultaneous tracking of multiple targets while maintaining the surveillance responsibility. The large fixed antenna array through its better beam focusing improves system sensitivity and tracking accuracy.

Background
A phased array antenna, as any other directional antenna, will receive signals from space only in the direction in which the beam is aimed. The maximum practical deflection on either side of antenna center of the phased array beam is 60 degrees. This limits the coverage from a single antenna face to 120 degrees. To provide surveillance across the horizon, the building housing the entire system and supporting the antenna arrays is constructed in the shape of a triangle. The two building faces supporting the arrays, each covering 120 degrees, will monitor 240 degrees of azimuth. The array faces are also tilted back 20 degrees to allow for an elevations deflection from three to 85 degrees above horizontal.
The radar system is capable of detecting and monitoring a great number of targets that would be consistent with a massive SLBM attach. The system must rapidly discriminate between vehicle types, calculating their launch and impact points in addition to the scheduling, data processing and communications requirements. The operation is entirely automatic, requiring people only for monitoring, maintenance and as a final check of the validity of warnings. Three different computers communicate with each other from the heart of the system, which relays the information to Cheyenne Mountain AS.

Point of Contact
Air Force Space Command, Public Affairs Office; 150 Vandenberg St., Suite 1105; Peterson AFB, CO 80914-4500; DSN 692-3731, or (719) 554-3731.

April 2003




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