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).

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(U) Future Space Based Radar (SBR)

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) SMC: Funding Source.
• (U) Air Force: Funding Source.

Images (U):

(U) None.

Related Initiatives (U):

This Table Is Unclassified.

Name	Title
BI-STATIC GEO/MEO SBR	Bi-static Geosynchronous/Medium Earth Orbit (GEO/MEO) Space-Based Radar (SBR)
BI-STATIC GEO/UAV SBR	Bi-static Geosynchronous/Unmanned Aerial Vehicle (GEO/UAV) Space-Based Radar (SBR)
MONO-STATIC SBR	Mono-static Space Based Radar (SBR)

Related Requirements (U): None.

Related Categories (U):

This Table Is Unclassified.

Name	Title
SBR	Space-Based Radar (SBR)

Road Map Placements (U):

This Table Is Unclassified.

Name	Title
SURVEILLANCE AND WARNING	SPACE FORCE ENHANCEMENT: SURVEILLANCE AND WARNING

Requirements, Funding and Additional Hotlinks (U):

(U) None.

Lead Office (U):

Air Force.

Point of Contact (U):

(U) National Security Space Road Map Team, NSSA, Open Phone: (703) 808-6040, DSN 898-6040.

Date Of Information (U):

(U) 21 November 1997

(U) Road Map Production Date: 23 June 2001