(U) Future Space Based Radar (SBR)

(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) The type of satellite constellation required for space based surveillance of the Earth's surface depends on the mission to be performed.  Phillips Laboratory, in concert with the Space and Missiles Systems Center and the Aerospace Corporation, recently completed a space based radar constellation study focused on the theater support mission, with emphasis on detecting airborne targets. The results of the study are being used to guide concept formulation for space based radars in the theater support role.

Description: (U)
(U) With the uncertain global political situation, there has been a shift in proposed space based radar applications.  The former emphasis on global surveillance has changed to focus on theater support.  One of the most important theater support missions is airborne target detection and tracking.  Radar provides significant advantages for airborne detection because of its ability for day, night and all-weather operation.  However, airborne target detection and tracking requires frequent data updates.  A study examined two distinct aspects of the constellation size problem to assess constellation sizes as a function of orbit parameters, radar capabilities, and theater size. First, the number of satellites needed to provide a maximum and average revisit time was determined based on total satellite field-of-regard.  This is a minimum number of satellites needed and is only a function of the altitude of the satellites. A second part of the study assessed the increased number of satellites required when realistic radar parameters are included. For that case, the search rate of the radar determines what part of the instantaneous field-of-regard can be actually covered by a satellite while it is over a theater of interest.  The results of this study are being used to evaluate system concepts regarding the number of satellites required to support a given mission.

(U) The Future Space Based Radar (SBR) will be the culmination of the concept analysis and technology risk reduction program.  A decision will be made on what type of satellite system to develop.  The three candidates include a Mono-static SBR, a Bi-static SBR with Geosynchronous (GEO) transmitters and Medium Earth Orbit (MEO) receivers, or a Bi-static SBR with Geosynchronous transmitters and unmanned aerial vehicles (UAVs) equipped as receivers.  

User Impact: (U)
(U) To be supplied.

Programmatics: (U)
(U) Concept/Technology.
	(U) Decision Point: 01/2000 (2QFY2000).
		(U)  The 1997-2000 timeframe is planned for SBR concept analysis and technology risk reduction investment.  Around the year 2000, a decision will be made on which concept design to pursue, based on the available technology and technology trends.  Based on current trends in launch capability, it is projected that any concept considered will not be deployable prior to 2005.
	(U) IOC: 10/2004 (1QFY2005).
	(U) FOC: 10/2008 (1QFY2009).

(U) Organizations and Funding:
	(U) SMC: Funding Source.
	(U) Air Force: Funding Source.

Related Initiatives: (U)
(U) BI-STATIC GEO/MEO SBR, BI-STATIC GEO/UAV SBR, MONO-STATIC SBR

Related Requirements: (U)
(U) None.

Related Categories: (U)
(U) SBR

Road Map Placements: (U)
(U) SURVEILLANCE AND WARNING.

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

Date of Information: (U)
21 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).)