(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.
(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.
(U) To be supplied.
|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)|
|SBR||Space-Based Radar (SBR)|
|SURVEILLANCE AND WARNING||SPACE FORCE ENHANCEMENT: SURVEILLANCE AND WARNING|
(U) National Security Space Road Map Team, NSSA, Open Phone: (703) 808-6040, DSN 898-6040.
(U) 21 November 1997
(U) Road Map Production Date: 23 June 2001