View source for AN/SPG-51

{{use mdy dates|date=October 2021}}
{{Infobox Radar 
|name        = AN/SPG-51
|image       = USS Richard E Byrd (DDG 23) aft.jpg
|caption     = The superstructure of the {{USS|Richard E. Byrd|DDG-23}} showing the ship's radars, 1983. There are two AN/SPG-51 directors shown directly in the center of the image.
|country     = [[United States]] 
|introdate   = 
|number      =
|type        = [[Pulse-Doppler radar]], Missile fire-control
|frequency   = * Illuminator: 10.25-10.5 GHz<ref name=adc016190/>
* Tracking Radar: 5.45 GHz - 5.825 GHz<ref name=adc016190/>{{efn|All data in infobox is for SPG-51D unless otherwise stated}}
|range       = Tracking Radar: {{cvt|100|nmi|km}}<ref name=adc016190/>
|altitude    =
|diameter    = 
|azimuth     = 360° at 12°/s<ref name=mechanically-scanning-antennas/>{{efn|name=unknown-version|It is uncertain as to which version of the SPG-51 this performance figure comes from.}}
|elevation   = -30° to 83°<ref name=mechanically-scanning-antennas>{{cite journal |journal=Electronic Progress |date=Winter 1974 |volume=16 |issue=4 |page=4 |title=Mechanically-Scanning Antennas |last1=Winter |first1=Charles F.|bibcode=1974ElPr...16....2W }}</ref>{{efn|name=unknown-version}}
|precision   = Fire control quality three-dimensional data
|power       = * Illuminator: 4000 W<ref name=adc016190/>
* Tracking Radar: 
** 1600 W average<ref name=adc016190/>
** 81 kW peak<ref name=adc016190/>
|manufacturer=[[Raytheon]]<ref name=naval-radar/>
|PRF         = * 4100 pps (surface)
* 9600-16700 pps (air)<ref name=adc016190/>
| beamwidth   = * Illuminator: 0.9° (horizontal), 0.9° (vertical)
* Tracking Radar: 1.6° (horizontal), 1.6° (vertical)
| pulsewidth  = Tracking Radar: 2.1-3.2 μs
}}
The '''AN/SPG-51''' is an American tracking / illumination [[fire-control radar]] for [[RIM-24 Tartar]] and [[RIM-66 Standard]] missiles. It is used for target tracking and [[surface-to-air missile|Surface-to-air]] [[missile guidance]] as part of the Mk. 73 gun and missile director system, which is part of the [[Tartar Guided Missile Fire Control System]].<ref name=janes-weapon-systems-1972-1973>{{Cite book |url=https://www.worldcat.org/oclc/655668873 |title=Jane's weapon systems. 1972-73: 4th ed. |date=1972 |publisher=Jane's Yearbooks |others=Ronald Thomas Pretty, Dennis Henry Ross Archer |isbn=0-354-00105-1 |location=London |pages=540 |oclc=655668873}}</ref>

Aircraft tracking is based on [[monopulse radar]] utilizing [[Pulse-Doppler radar]] signal processing in MK 74 MOD 14 and MK 74 MOD 15. The MK 74 MOD 15 configuration includes [[continuous-wave radar]] tracking in addition to pulse-Doppler tracking. It provides illumination for [[bistatic radar]] operation associated with missile guidance in all configurations. Older systems rely on [[conical scanning]] rather than monopulse.

In accordance with the [[Joint Electronics Type Designation System]] (JETDS), the "''AN/SPG-51''" designation represents the 51st design of an Army-Navy electronic device for waterborne fire control radar equipment. The JETDS system also now is used to name all [[Department of Defense]] electronic systems.

==Platforms==

==={{Navy|France}}===
* {{sclass|T 47|destroyer}} (Du Chayla subclass post AAW modernization)<ref name=":0">{{Cite book |last=Jordan |first=John |url=https://www.worldcat.org/oclc/13010345 |title=An illustrated guide to modern destroyers |date=1986 |publisher=Prentice Hall |isbn=0-13-450776-2 |location=New York, N.Y. |oclc=13010345 |pages=58, 70, 77, 79, 134}}</ref><ref name=":1">{{Cite book |url=https://www.worldcat.org/oclc/5798981 |title=The World's navies |date=1979 |publisher=David and Charles |others=Christopher Chant |isbn=0-7153-7689-6 |location=Newton Abbot [England] |oclc=5798981|pages=63,92-93,104,122,229,231,241}}</ref>
* {{sclass|Cassard|frigate}}<ref name=combat-fleets-of-the-world>{{Cite book |url=https://www.worldcat.org/oclc/14161346 |title=Combat fleets of the world : their ships, aircraft, and armament, 1986/87 |date=1986 |publisher=Naval Institute Press |others=Jean Labayle Couhat, United States Naval Institute |isbn=0-85368-860-5 |edition=6th |location=Annapolis, Md. |pages=13,123,420,643 |oclc=14161346}}</ref>
==={{Navy|West Germany}}===
*{{sclass|Lutjens|destroyer}}<ref name=":1" />
==={{Navy|Italy}}===
*{{sclass|Audace|destroyer}}<ref name=":1" />
*{{sclass|Durand de la Penne|destroyer}}<ref>{{Cite book |url=https://www.worldcat.org/oclc/652063550 |title=Jane's fighting ships, 2009-2010 2009/2010 |date=2009 |publisher=Jane's Information Group |others=Stephen Saunders |isbn=978-0-7106-2888-6 |edition=112th |location=Coulsdon |pages=395 |oclc=652063550}}</ref>
*{{sclass|Impavido|destroyer}}<ref name=":0" /><ref name=":1" />
==={{navy|Japan}}===
*{{sclass|Amatsukaze|destroyer}}<ref name=":0" />
*{{sclass|Hatakaze|destroyer}}<ref name=":0" />
*{{sclass|Tachikaze| destroyer}}<ref name=":1" />
==={{Navy|Australia}}===
*{{sclass|Perth|destroyer}}<ref name=combat-fleets-of-the-world/>
==={{Navy|Netherlands}}===
*{{sclass|Tromp|frigate}}<ref name=":1" />

=== {{naval|Spain}} ===
*{{sclass|Baleares|frigate}}<ref name=combat-fleets-of-the-world/>
==={{navy|US}}===
*{{sclass|Albany|cruiser}}<ref name=GMM-3-2>{{cite book |title=NAVEDTRA 10199-C: Gunner's Mate M 3 & 2 |publisher=Naval Education and Training Support Command |year=1977 |page=147 |url=https://books.google.com/books?id=Qk8IadGw51cC}}</ref>
*{{sclass|Brooke|frigate}}<ref name=combat-fleets-of-the-world/>
*{{sclass|California|cruiser}}<ref>{{Cite book |url=https://www.worldcat.org/oclc/20284225 |title=Jane's strategic weapons systems |date=1989 |publisher=Jane's Information Group |others=Duncan Lennox, Roger Loasby, Jane's Information Group |isbn=0-7106-0880-2 |edition=1st |location=Coulsdon, Surry, Eng. |pages=405 |oclc=20284225}}</ref>
*{{sclass|Charles F. Adams|destroyer}}<ref name=":1" />
*{{sclass|Forrest Sherman|destroyer}} (DDG conversion with Tartar)
**{{USS|Decatur|DDG-31}}
**{{USS|John Paul Jones|DDG-32}}
**{{USS|Parsons|DDG-33}}
**{{USS|Somers|DDG-34}}<ref name=":1"/>
*{{sclass|Kidd|destroyer}}<ref name=":0" />
*{{sclass|Virginia|cruiser}}<ref name=":1" />

==Variants==
* '''SPG-51:''' Original Model.
* '''SPG-51B:''' Upgraded SPG-51 designed for use with Improved Tartar (IT) missile.<ref>{{Cite journal |date=1965-07-01 |title=Evaluating the DDG |url=https://www.usni.org/magazines/proceedings/1965/july/evaluating-ddg |access-date=2023-02-18 |language=en |journal=Proceedings of the U.S. Naval Institute|volume=91|issue=7|page=749}}</ref>
* '''SPG-51C:''' Automatic acquisition and tracking, increased reliability, and improved [[Electronic counter-countermeasure|ECCM]] capabilities, clutter rejection, and multiple target resolution.<ref name="naval-radar" />
* '''SPG-51D:''' Klystron replaced with [[traveling-wave tube]] to permit the transmission to be chosen from a much wider bandwidth. Increased use of integrated circuitry and digital circuitry.<ref name=adc016190>{{cite report |url=https://archive.org/details/DTIC_ADC016190 |title=Reliability of Naval Radar Systems |last1=Hemenway |first1=D.F. |last2=Navid |first2=B.N. |publisher=Naval Research Laboratory |location=Washington D.C. |date=September 1978 |pages=83–88}}</ref>
* '''SPG-51E:''' Proposed "universal fire control radar" capable of controlling the [[RIM-8 Talos]] as well as Tartar.<ref name=naval-radar>{{Cite book |last=Friedman |first=Norman |url=https://www.worldcat.org/oclc/8262709 |title=Naval radar |date=1981 |publisher=Naval Institute Press |isbn=0-87021-967-7 |location=Annapolis, Md. |pages=179–180 |oclc=8262709}}</ref> Not built in quantity.<ref>{{Cite book |last=Friedman |first=Norman |url=https://www.worldcat.org/oclc/20098065 |title=The Naval Institute guide to world naval weapons systems |date=1989 |publisher=Naval Institute Press |others=United States Naval Institute |isbn=0-87021-793-3 |location=Annapolis, Md. |pages=201 |oclc=20098065}}</ref>
<gallery>
File:TARTAR fire control radars mg 5851.jpg|AN/SPG-51 radars of a ''Cassard'' class frigate
</gallery>

== References ==
{{Reflist}}
== Notes ==
{{Notelist}}

==See Also==
{{Portal|Electronics}}
*[[List of radars]]
*[[List of military electronics of the United States]]

==External links==
*[http://www.fas.org/man/dod-101/sys/ship/weaps/mk-74.htm MK-74 Guided Missile Fire Control System (GMFCS)]
*[http://www.globalsecurity.org/military/systems/ship/systems/an-spg-51.htm AN/SPG-51D Missile Director Radar]

[[Category:Sea radars]]
[[Category:Military electronics of the United States]]

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