AN/SPQ-11 explained

AN/SPQ-11
Country:	United States
Introdate:	1983
Number:	1
Type:	Passive electronically scanned array radar
Frequency:	2900-3100 MHz (E\F band)

The AN/SPQ-11 Cobra Judy was a PESA radar found on the missile range instrumentation ship.

It was used for space tracking, ballistic missiles tracking and other instrumentation. Cobra Judy was the sea component of the COBRA program for monitoring missile launches and outer space. Cobra Judy was replaced by the Cobra Judy Replacement (CJR) in April 2014.

Classification of radar systems

Under the Joint Electronics Type Designation System (JETDS), all U.S. military radar and tracking systems are assigned a unique identifying alphanumeric designation. The letters “AN” (for Army-Navy) are placed ahead of a three-letter code.^[1]

• The first letter of the three-letter code denotes the type of platform hosting the electronic device, where A=Aircraft, F=Fixed (land-based), S=Ship-mounted, and T=Ground transportable.
• The second letter indicates the type of equipment, where P=Radar (pulsed), Q=Sonar, and R=Radio.
• The third letter indicates the function or purpose of the device, where G=Fire control, Q=Special Purpose, R=Receiving, S=Search, and T=Transmitting.

Thus, the AN/SPQ-11 represents the 11th design of an Army-Navy “Ship-mounted, Radar, Special Purpose” electronic device.^{[1] [2]}

Replacement

The Cobra Judy Platform, was taken out of service and stricken from the Naval Vessel Register March 31, 2014.^[3] On 31 March 2014, the Cobra Judy Replacement program, aboard reached initial operational capability (IOC). According to the Naval Sea Systems Command (NAVSEA), the U.S. Air Force also assumed operational and sustainment responsibilities for the ship.^[4] The inertial navigation system for the antenna stabilization and alignment had been provided by iMAR Navigation.

See also

• • , platform for Cobra King, the Cobra Judy Replacement
• Cobra Dane
• Cobra Ball
• Cobra Eye
• List of military electronics of the United States

External links

• FAS Intelligence Resource Program - AN/SPQ-11 Cobra Judy

Notes and References

1. Book: Avionics Department. Electronic Warfare and Radar Systems Engineering Handbook. 4. Missile and Electronic Equipment Designations. 2-8.1. Naval Air Warfare Center Weapons Division. Point Mugu, California. 2013.
2. Book: Winkler, David F.. Searching the Skies: The Legacy of the United States Cold War Defense Radar Program. Radar Systems Classification Methods. 73. United States Air Force Headquarters Air Combat Command. Langley AFB, Virginia. 1997. 97020912.
3. Web site: [{{Naval Vessel Register URL|id=AGM23}} USNS OBSERVATION ISLAND (T-AGM 23) ]. Naval Vessel Register . 2 March 2012.
4. News: Cobra Judy Replacement Achieves Initial Operational Capability . Navy.mil . 1 May 2014 . 8 May 2014 . No. NNS140501-26.