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Overview (U):

(U) The COBRA GEMINI system is a transportable dual frequency (S- and X-band) radar designed to collect precise scientific and technical intelligence (S&TI) data against rest of world (RoW) medium range ballistic missiles. A secondary mission is to collect similar data for United States theater missile defense systems testing. The radar system is capable of land based and sea based operation. The radar's seven subsystems are housed in 20 foot ISO containers for ease of shipment aboard USAF Air Mobility Command transport aircraft. When sea based, the containers will be temporarily installed on board a T-AGOS class U.S. Navy ship. The prototype system is currently in development by MIT/LL and is scheduled for operational availability in the second quarter of FY99. Two production systems were eliminated from the FY98 budget because of funding constraints.

Description (U):

(U) The COBRA GEMINI Gemini system is based on several legacy systems including COBRA JUDY. However, COBRA GEMINI is not a replacement for COBRA JUDY. The systems complement each other to provide robust coverage of strategic (JUDY) and theater (JUDYand GEMINI) missile testing and treaty verification.

(U) The system collects dual frequency, high precision metric and signature intelligence (MASINT) data on targets of interest. The S- and X-band transmitters are phase-coherent, broadband power amplifiers, which use CPI high power Cavity Coupled Traveling Wave Tubes (CCTWTs). Both frequencies are transmitted through a dual-band Cassegrain feed and a common 5-meter aperture parabolic dish antenna. Four S-band tubes provide 50kW average power and one X-band tube produces 35kW average power. The S-band radar has a beam width of 1.24 degrees. S-Band performs surveillance (target detection and acquisition), narrow-band tracking, and wide-band imaging. The X-band radar has a beam width of 0.4 degrees that is centered in the S-band field of view. X-Band is slaved to the S-band tracker, and collects narrow-band and wide-band metric data as well as wide-band imaging data.

(U) The system uses super-hetrodyne receivers. The S-band system uses a double-down conversation receiver, while the X-band system uses a triple down-conversion receiver. The instantaneous bandwidth is 300 MHz and 1GHz at S- and X-band, respectively. Both receivers use High Electron Mobility Transistor (HEMT) amplifiers.

(U) The main computer is a Silicon Graphics' Power Challenge XL. It runs the IRIX 6.2 real-time UNIX operating system. The console and displays are made up of six Silicon Graphics' INDX Graphics Workstations which use R-4600 processing units.

(U) MASINT programs are directed by the Defense Intelligence Agency and Central MASINT Office (DIA and CMO). Requirements are established by all government agencies and validated by CMO. The Ballistic Missile Defense Organization (BMDO) plans to use COBRA GEMINI for data collection during theater missile defense system testing. The Electronics System Center's Information Operations SPO (ESC\IYS) manages the prototype development and testing by MIT/LL. National Air Intelligence Center (NAIC) provides processing and data exploitation services. Headquarters Air Intelligence Agency (HQ AIA) is responsible for radar operations. When sea based, the U.S. Navy T-AGOS Project Office will operate and maintain the ship.

(U) COBRA GEMINI is one of a suite of Measurements and Signatures Intelligence (MASINT) sensors funded by the General Defense Intelligence Program budget PE 31315. HQ USAF/XOI (previously HQ USAF/INR) is the program and funding execution organization for MASINT sensors.

User Impact (U):

(U) Data collected by COBRA GEMINI will validate and update Radar Cross Section (RCS) and Target Object Map (TOM) databases and models for theater missile defense (TMD) systems. Missile technology proliferation, development, and modifications constantly invalidate current estimates. These models are essential for TMD systems to effectively intercept enemy systems.

(U) Intelligence data from the system will be used by all military services, the Ballistic Missile Defense Organization (BMDO), and the Arms Control and Disarmament Agency (ACDA).

Programmatics (U):

(U) Programmed.

(U) Organizations and Funding:
  • (U) Air Force.

Images (U):

(U) None.

Related Initiatives (U):
LRDBTRLong Range Dual Band Transportable Radar (LRDBTR)
This Table Is Unclassified.

Related Requirements (U):None.

Related Categories (U):
Ground-Based WarningGround-Based Warning Sensors
This Table Is Unclassified.

Road Map Placements (U):

This Table Is Unclassified.

Requirements, Funding and Additional Hotlinks (U):

1997 Force Enhancement STW
This Table Is Unclassified.

Lead Office (U):

(U) Air Force.

Point of Contact (U):

(U) Maj Donald Landing, ESC, Open Phone: None..

Date Of Information (U):

(U) 10 November 1997

(U) Road Map Production Date: 12 July 1999

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