(U) PAVE Phased Array Warning System (PAWS)

(The effects of any budget/program decisions made since the information was collected during 1997-98 are NOT reflected in the National Security Space Road Map (NSSRM).)

Overview: (U)
(U) PAVE PAWS (Phased Array Warning System) is an Air Force Space Command radar system providing missile warning and space surveillance.  PAVE PAWS radars are located at Cape Cod Air Force Station (AFS), MA; Beale Air Force Base (AFB), CA; Eldorado AFS, TX; and Robins AFB, GA.  The Eldorado and Robins sites were placed in caretaker status by AFSPC in Sep 95, and are not currently performing their mission, although they could be reconstituted.     

(U) The radar system is used primarily to detect and track sea-launched and intercontinental ballistic missiles (SLBM and ICBM) with a secondary mission of detecting and tracking earth orbiting satellites.  Information received from the PAVE PAWS radar systems pertaining to SLBM, ICBM and satellite detection is forwarded to Space Command's Missile Warning and Space Control Centers at Cheyenne Mountain AFB, CO. Data is also sent to the National Military Command Center (NMCC) and the U.S. Strategic Command (USSTRATCOM).

Description: (U)
(U) The unique aspect of the PAVE PAWS radar system is the dual-faced phased array antenna technology. This system differs from a mechanical radar that must be physically aimed at an object in space to track or observe it. The phased array antenna is in 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 surveillance. 

(U) The large fixed antenna array, using its beam focusing, improves system sensitivity and tracking accuracy.  A phased array antenna, as any other directional antenna, receives 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 antenna arrays is constructed in the shape of a triangle.  The two building faces supporting the arrays, each covering 120 degrees, are therefore able to monitor 240 degrees.  The array faces are also tilted back 20 degrees to allow for an elevation deflection from three to 85 degrees above the horizon.  The lower limit provides receiver isolation from signals returned from ground clutter and for environmental microwave radiation hazard protection of the local area.  

(U)  The radar system is capable of detecting and monitoring a great number of targets that would be consistent with a massive SLBM attack. The system rapidly discriminates 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 the validity of warnings. Three different computers communicating with each other form the heart of the system, which relays the information to Cheyenne Mountain AFB.  

User Impact: (U)
(U) Loss of this capability would have a significant impact on the Space Surveillance Network (SNN).

Programmatics: (U)
(U) Operational.
	(U) Termination: 10/2010 (1QFY2011).
		(U)  The termination date for the PAVE PAWS radars corresponds with the operation of the Long Range Dual Band Transportable Radar.

(U) Organizations and Funding:
	(U) AFSPC: Funding Source.

Related Initiatives: (U)
(U) Beale, Cape Cod, SCC/ALTERNATE SCC

Related Requirements: (U)
(U) None.

Related Categories: (U)
(U) Collateral Sensors

Road Map Placements: (U)
(U) National Security Space Road Map, SPACE CONTROL: S.S. NETWORK.

Lead Office: (U)
(U) Air Force.

Date of Information: (U)
12 November 1997

(The effects of any budget/program decisions made since the information was collected during 1997-98 are NOT reflected in the National Security Space Road Map (NSSRM).)