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The AN/SPY-1 radar antennas are the light grey octagonal panels on the front and starboard side of the superstructure of USS Lake Erie.
Country of originUnited States
Introduced1973; 51 years ago (1973)[1]
Type3D Air search
FrequencyS band[1]
Range370 km (200 nmi; 230 mi)[1][2]
Power6 MW

The AN/SPY-1[a] is a United States Navy 3D radar system manufactured by Lockheed Martin. The array is a passive electronically scanned system and a key component of the Aegis Combat System. The system is computer controlled and uses four complementary antennas to provide 360-degree coverage. The system was first installed in 1973 on USS Norton Sound and entered active service in 1983 as the SPY-1A on USS Ticonderoga. The -1A was installed on ships up to CG-58, with the -1B upgrade first installed on USS Princeton in 1986. The upgraded -1B(V) was retrofitted to existing ships from CG-59 up to the last, USS Port Royal.



The first production model of the SPY-1 series is SPY-1, which forms the baseline configuration of all subsequent SPY-1 radars. SPY-1A has four antenna arrays in two separate deckhouses, with each antenna array containing 148 modules. Each module contains up to 32 radiating elements and phase shifters, and modules are paired to form transmitting and receiving sub-arrays, which are grouped into 32 transmitting and 68 receiving arrays. Transmitting arrays are driven by eight transmitters, each with four crossed-field amplifiers (CFAs). Each CFA produces a peak power of 132 kW. There are 4,096 total radiators, 4,352 receivers, and 128 auxiliary elements on each antenna array. The power requirement of SPY-1A is four times that of the AN/SPS-48. The AN/UYK-7 computer controls SPY-1.[5]: 316–317 

SPY-1A is a development of SPY-1, resulting from the deployment of SPY-1-equipped USS Ticonderoga off the Lebanese coast. It was discovered that the false alarm rate was high because the radar would pick up swarms of insects and clutter from mountainous terrain. The solution was to allow the operator to change the sensitivity profile of radar by periodically reducing attenuation, and setting threat and non-threat sectors according to changing environment.[5]: 316–317  The result was more efficient utilization of resources. About 10% of the software totaling thirty thousand lines were rewritten to accommodate the necessary upgrade.[5]: 316–317  In 2003, the U.S. Navy donated a SPY-1A antenna to the National Severe Storms Laboratory in Norman, Oklahoma, making it one of the first stationary phased arrays used in weather forecasting. The Multifunction Phased Array Radar was decommissioned and removed in 2016.

SPY-1B adopts VLSI, resulting in increased performance and reduced size and weight. For example, the electronic cabinets area was reduced from 11 to 5, with the corresponding weight reduced from 14,700 lb (6,700 kg) to 10,800 lb (4,900 kg), and separate digital modules are reduced from 3,806 to 1,606.[5]: 316–317  A 7-bit phase shifter replaced the 4-bit phase shifter in earlier models, with the corresponding weight of phase shifters in the face of the antenna reduced from 12,000 lb (5,400 kg) to 7,900 lb (3,600 kg), and a reduction of the side lobe by 15 dB. There are 4,350 radiators with two side lobe cancellation antennae, each with two elements, and the radar uses eleven 16-bit microprocessors. The ability to counter steep diving missiles was improved with more energy at higher elevations or longer pulse.[5]: 316–317 

SPY-1B(V) is a development of earlier SPY-1B with moving target indication capability incorporated in 1997.[5]: 316–317 

SPY-1D was first installed on USS Arleigh Burke (DDG-51) in 1991, with all antennas in a single deckhouse. It is a variant of the -1B to fit the Arleigh Burke class using the UYK-43 computer, with the main antenna also used as missile uplinks, thus eliminating the need for separate missile uplinks in earlier models. The AN/UYA-4 display in earlier models is replaced by the UYQ-21 display.[5]: 316–317  Starting with Flight III (DDG-125), the Arleigh Burke class is being equipped with AN/SPY-6(V)1 radar from Raytheon; Flight IIA (DDG-79 to DDG-124) will be retrofitted with the AN/SPA-6(V)4 variant.[6][7]

SPY-1D(V), the Littoral Warfare Radar, was an upgrade introduced in 1998 with a new track initiation processor for high clutter near-coast operations, where the earlier "blue water" systems were especially weak. The waveform is coded and signal processing is improved.[5]: 316–317  The ability to resist electronic attack was also improved.[8]

SPY-1E SBAR (S-Band Active Array) is the only active electronically scanned array (AESA) model in the SPY-1 series. SPY-1E utilizes commercial off-the-shelf (COTS) subsystems, and a single-faced demonstration unit was built in 2004. The weight of the antenna remains the same, but the weight below the deck is greatly reduced.[5]: 316–317  It was later renamed the AN/SPY-2 and subsequently developed into AN/SPY-4 Volume Search Radar (VSR) for Zumwalt-class destroyers and Gerald R. Ford-class aircraft carriers to complement their AN/SPY-3 X-band radar. VSR was removed from the Zumwalt class due to budgetary concerns and will be replaced with Raytheon AN/SPY-6 on the Gerald R. Ford class starting with USS John F. Kennedy (CVN-79).[9]

SPY-1F FARS (frigate array radar system) is a smaller version of the 1D designed to fit frigates. It is used in Norwegian Fridtjof Nansen-class frigates. The origin of the SPY-1F can be traced back to the FARS proposed to the German Navy in the 1980s. The size of the antenna of SPY-1F is reduced from the original 12 ft (4 m) with 4,350 elements to 8 ft (2.4 m) with 1,856 elements, and the range is 54% of the SPY-1D.[5]: 316–317  It is not used by the U.S. Navy, although there were proposals to retrofit Freedom-class littoral combat ships.

SPY-1F(V) is a derivative of SPY-1F with improved capability against littoral targets and cruise missiles and better multi-mission capability.[5]: 316–317 

SPY-1K is the smallest version of the radar currently offered, based on the same architecture as the 1D and 1F. It is intended for use on very small vessels such as corvettes, where the SPY-1F would be too large. The size of the antenna is further reduced to 5 ft (1.5 m) with 912 elements.[5]: 316–317  As of 2007, none were in service, although the radar is incorporated into the design of the yet-unbuilt AFCON Corvette [es].[10][11]





The following specifications apply to the SPY-1A/B/D series.[5]

  • Size: 12 ft (3.7 m) octagon
  • Weight above deck: 13,030 lb (5,910 kg) per face
  • Weight below deck:131,584 lb (59,685 kg)
  • Range: 175 nmi (201 mi; 324 km)
    • 45 nmi (52 mi; 83 km) against sea-skimming missiles
  • Targets simultaneously tracked: 200 each array, 800 total
  • Band: S-band 3–4 GHz; wavelength 7.5 cm10 cm[14]
  • PRF: variable
  • Scan rate (scan/min): 1 (horizon), 12 (above horizon)
  • Peak Power: 6 MW[14]
  • Average Power: 58 kW[14]
  • Duty cycle: 1/100 seconds (1%)[14]
  • Antenna Gain: 9,300[14]


JS Ashigara with AN/SPY1D(V)

Air and Missile Defense Radar


In July 2009, Lockheed Martin was one of three companies awarded contracts to study the development of a new Air and Missile Defense Radar (AMDR) to be composed of an S-Band radar, an X-Band radar, and a Radar Suite Controller to defend against evolving anti-ship and ballistic missile threats.[15]

See also



  1. ^ Army Navy Joint Electronics Type Designation System / S - Water (surface ship), P - Radar, Y - Surveillance (target detecting and tracking) and Control (fire control and/or air control), model number[4]


  1. ^ a b c Missile Defense Project (23 June 2021) [7 April 2016]. "AN/SPY-1 Radar". Missile Threat. Center for Strategic and International Studies. Archived from the original on 6 August 2022. Retrieved 13 August 2022.
  2. ^ Lewis, George; Postol, Theodore (23 October 2012). "Ballistic Missile Defense: Estimating the Range of an Aegis Radar against a Missile Warhead Target". mostlymissiledefense. Archived from the original on 13 May 2022. Retrieved 13 August 2022.
  3. ^ "CG 47 CLASS ADVISORY NR. 04-97, HERP-HERO GUIDANCE". Federation of American Scientists. 1997-06-17. Archived from the original on 21 August 2010. Retrieved 2022-08-13.
  4. ^ Joint Electronics Type Designation System
  5. ^ a b c d e f g h i j k l m Friedman, Norman (15 May 2006). The Naval Institute Guide to World Naval Weapon Systems (5th ed.). Annapolis, Maryland: Naval Institute Press. pp. 316–317. ISBN 978-1557502629. LCCN 2005031194. OCLC 1131518158. OL 3415017M – via Google Books.
  6. ^ "U.S. Navy's SPY-6 Family of Radars". Raytheon Missiles & Defense. n.d. Archived from the original on 15 July 2022. Retrieved 13 August 2022.
  7. ^ Katz, Justin (11 January 2022). "Raytheon to start backfitting destroyers with SPY-6 radar". Breaking Defense. Archived from the original on 7 June 2022.
  8. ^ "AN/SPY-1 Radar". man.fas.org. Retrieved 2022-08-31.
  9. ^ LaGrone, Sam (22 August 2016). "Raytheon Awarded $92M Navy Contract for Future Carrier, Big Deck AESA Radars". USNI News. United States Naval Institute. Archived from the original on 12 May 2022. Retrieved 18 August 2022. Based on Raytheon's SPY-6 S-band Air and Missile Defense Radar (AMDR) planned for the services Arleigh Burke-class (DDG-51) guided missile destroyers, the Enterprise Air Surveillance Radar (EASR) will be the volume air search radar for most of the Gerald R. Ford-class carrier (CVN-78) — starting with John F. Kennedy (CVN-79) and the planned LHA-8 amphibious warship.
  10. ^ "The AFCON Products". Lockheed Martin. n.d. Archived from the original on 26 February 2009. Retrieved 18 August 2022. The AFCON Corvette has been designed with advanced features in mind, including a SPY-1K phased array radar, a hull mounted sonar system, a 76 mm Gun, a four-cell MK 41 Vertical Launching System (VLS) and an Aegis-based Combat System.
  11. ^ Pike, John (7 July 2011). "AN/SPY-1 Radar". GlobalSecurity.org. Archived from the original on 19 March 2022. Retrieved 18 August 2022.
  12. ^ "SPY-1 Family of Radars: Battle-Proven Naval Radar Performance" (PDF). Lockheed Martin. 2009. Archived from the original (PDF) on 15 September 2011. Retrieved 18 August 2022.
  13. ^ Vision, Presence, Power: A Program Guide to the U.S. Navy (2004 ed.). United States Department of the Navy. 2004. p. 86.
  14. ^ a b c d e Moen, Bente E.; Møllerløkken, Ole Jacob; Bull, Nils; Oftedal, Gunnhild; Mild, Kjell Hansson (2013). "Accidental exposure to electromagnetic fields from the radar of a naval ship: a descriptive study". International Maritime Health. 64 (4): 177–182. doi:10.5603/imh.2013.0001. hdl:11250/2384994. ISSN 2081-3252. PMID 24408137.
  15. ^ "Lockheed Martin To Develop Concept For New U.S. Navy Air And Missile Defense Radar" (Press release). Lockheed Martin. 14 July 2009. Archived from the original on 18 August 2022. Retrieved 18 August 2022. The U.S. Navy has awarded Lockheed Martin a $10 million firm-fixed-price contract to perform concept studies for the Air and Missile Defense Radar (AMDR), a scalable solid-state radar suite for future surface combatants.

Further reading