BPS-15/BPS-16
This is a low-power, surface search and navigation radar fitted in US nuclear-propelled submarines. The antenna is a horn array with a 40-in (1.02-m) aperture.
An update that improved the mechanical reliability ofthe radar mast resulted in
the BPS-16.
DEVELOPMENT •
Initial operational capability in the early 1960s. Manufactured by Unisys, Great Neck, New York.
The contract was awarded to Sperry Rand (later Unisys) after protest. The BPS-16 is currently in production for the Los Angeles (SSN 688)- , Seawolf-, and Ohio-class submarines as well as already operating in Sturgeon (SSN 637)-class submarines.
provement factor further weeds out clutter.
DEVELOPMENT •
Manufactured by the Westinghouse Defense Electronics Center of Baltimore, Maryland. Switzerland procured five radars, the first being delivered in 1987.
SPECIFICATIONS •
BAND E/F (2.9-3.1 GHz) RANGE 60 nm (69 mi; 110 km)
ACCURACY
azimuth 0.40°
height +/-902 ft (275 m)
range 130 ft (45 m)
RESOLUTION
azimuth 1.6°
range 739 ft (225 m)
PEAK POWER 90 kW
ELEVATION COVERAGE -3°/ + 20°
SPECIFICATIONS •
BAND I-J
PEAK POWER 35 kW BEAMWIDTH 3° X 13°
PULSE LENGTH 0.1 or 0.5 microsec PRF 1,500 or 750 Hz
SYSTEM GAIN 25 dB RANGE RESOLUTION
short-range mode
90 ft (27.4 m) long-range mode
300ft (91.4m) SCAN RATE up to 9.5 rpm
MK 23 Target Acquisition System (TAS)
The Mk 23 is a Two-Dimensional (2D), pulse-Doppler weapons direction radar for the NATO Sea Sparrow missile. It interfaces with the AN/SLQ-32 Electronic Countermeasures (ECM) system and with the Mk 68 gunfire control system.
The Mk 23 automatically reacts to incoming sea-skimming, high-angle, or pop-up missiles launched from surface ships, high-altitude aircraft, or submarines. It is designed to operate in severe jamming and high-clutter environments, using digital signal and Moving Target Indicator (MTI) processing. A Traveling Wave Tube (TWT) is used to turn the radar on and off rapidly, increasing its ECM resistance. The system can track 54 missiles simultaneously.
Its linear-array antenna is mounted back-to-back with an Identification Friend or Foe (IFF) antenna on a roll-stabilized platform, which rotates for a 360° scan in azimuth. The main reflector is fed by 26 flared feed horns. Additional sidelobe-blanking and sidelobe-can-cellation horns complete the array.
The Mk 23 has normal, medium-range, mixed, and emission control operational modes. The normal, or point defense mode, has a two-second data rate (30 rpm). Slowing the radar scan to 15 rpm allows for radar surveillance and aircraft control. These two modes are combined in the mixed mode for a high data rate providing rapid response and air control over a large area.
Emission control consists of several modes that are divided into the fully quiet modes or modes that narrow the sector to be scanned to a few degrees.
Although designed for total automatic operations, the Mk 23 has operator interface controls in the display unit for manual initiation of automation levels, override, and control. Only two crew members operate the Mk 23, one for fire control and the other for the improved point defense missile system.
TAS(I) is an improved 2D/3D system with a rotating phased-array (six-dipole) antenna fed by diode phase shifters that can steer two or more 11° beams simultaneously and much more powerful signal processing. Development began in 1986, but deployment was delayed by funding cutbacks and program reorientations.
VARIANTS •
Mod 0 had a Mk 158 computer and was the development model in the frigate Dowries (FF 1070).
Mod 1 introduced the UYK-20 computer and is integrated into the Naval
Tactical Data System (NTDS) in the
Spruance class. Mod 3 is modified Mod 1 with AN/UYQ-21 display. Mod 5 is Mod 1 with AN/UYK-44 computer for Spruance class. Mod 7 is Mod 1 with UYK-44.
Mod 2 is a stand-alone model with AN/ UYA-4 console (without NTDS); for major replenishment ships. Mod 4 is Mod 2 with UYQ-21 display. Mod 6 is Mod 2 with UYK-44. Mod 8 is Mod 2 with UYK-44 and UYQ-21 display.
DEVELOPMENT •
Five different systems—Mk 20 through Mk 24—were evaluated, each succeeding Mk represen-tating greater sophistication in some area. The Mk 23 was evaluated in the Dowries (FF 1070) from 1975 to 1983, with the system achieving initial operational capability in 1980. Manufactured by Hughes Aircraft Co., Fullerton, California.
In service in all active aircraft carriers, Spruance (DDG 963)-class destroyers, Wasp (LHD l)-class amphibious assault ships, and the Sacramento (AOE 1)-, Supply (AOE 6)-, and Wichita (AOR 1)-class auxiliary ships.
SPECIFICATIONS •
BAND D
RANGE 30 rpm 20 nm (23 mi; 37 km);
15 rpm 90 nm (104 mi; 167 km) PEAK POWER 200 kW PRF normal 4,000 Hz; medium-range
900 Hz SYSTEM GAIN 21 dB
MTI CLUTTER REDUCTION more than 50 dB
SYSTEM WEIGHT
topside 2,000 Ibs (907 kg) total 10,000 Ibs (4,536 kg)
ANTENNA DIMENSIONS
width 19 ft 3 in (5.87 m)
height 10 ft 9 in (3.28 m)
ANTENNA BEAMWIDTH 3.3° X 75°
Mk91
This continuous-wave fire control radar is associated with the short-range NATO Sea Sparrow Missile System (NSSMS). Side-by-side Mk 95 parabolic transmitting and Cassegrain lens receiving I-band antennas ride on a single pedestal mounted near the eight-cell launcher. The transmitter’s radome is convex, the receiver’s is concave.
To expand the tracker’s field of view, the Mk 95 uses a wide-beam illuminator that allows the missile (a modified Sparrow III AAM) to use proportional navigation. An electro-optical tracker fitted between the Mk 95s provides an alternate tracking method in high-ECCM conditions.
VARIANTS •
Few ships use the single Mod 0. The dual Mod 1 equips ships in the Danish, Italian, Japanese, Norwegian, and US navies.
A “Netherlands” form uses the Mk 73 fire control transmitter linked with the Dutch M25 fire control system; Belgian, German, Netherlands Navy, and Spanish ships use the Netherlands version.
DEVELOPMENT •
Entered service in the 1970s. Manufactured by Raytheon, Wayland, Massachusetts. Used on many surface combatants as well as some amphibious and auxiliary ships of the US Navy. Also used in the Belgian, Danish, German, Italian, Japanese, Norwegian, and Spanish navies.
SPECIFICATIONS •
BAND I/J
PEAK POWER 2 kW average, continuous-wave mode
ANTENNA DIAMETER 3 ft 3 in (1.0 m)
ANTENNA MOUNT DIMENSIONS 8 ft 4 in (2.54 m) X 8 ft (2.44 m)
ANTENNA WEIGHT 3,315 lb (1,504 kg)
MK92
The Mk 92 is a gun and missile fire control system that performs tracking and illumination functions using two antennas in a Combined Antenna System (CAS) mounted above and below a supporting arm inside a distinctive egg-shaped dome. It is based on the Dutch WM28 fire control system and is produced in the United States under license from Hollandse Signaalapparaten.
The upper, inverted Cassegrain lens antenna uses monopulse tracking and Continuous-Wave Injection (CWI) for three-dimensional target acquisition and illumination. The lower, truncated paraboloid antenna uses a high scan rate (60 rpm) for search and includes a limited height-finding capability by shifting the beam in a spiral elevation pattern. The search radar also has 10 Identification Friend or Foe (IFF) dipoles across its face. Each antenna is capable of Track-While-Scan (TWS) processing, tracking two targets while scanning for others.
A Mk 106 Weapons Control Console (WCC) has a Plan Position Indicator (PPI) and two track displays. The Mod 2 variant adds the Separate Target Illumination Radar’s (STIR) Mk 107 WCC
with its own PPI.
In the late 1980s, Unisys developed a Coherent Receive/Transmit (CORT) kit to upgrade Perry-class Mod 2 radars. April 1989 tests showed that CORT provided a “significant improvement in clutter rejection” and showed increased resistance to jamming. In addition, the Mk 92 Mod 6 detected targets with much smaller radar
cross sections at similar ranges, doubled the detection and tracking ranges of the Mod 2, and showed an improved ability to track and hold lock on targets as well as decreasing reaction times.
The Ingraham (FFG 61) was the only PAry-class ship completed with the CORT. Others are being upgraded, with six kits ordered in 1988 and seven more ordered in October 1990.
Mk 94 was a prototype fitted in the hydrofoil missile patrol boat Pegasus.
VARIANTS •
Mk 92 Mod 0 is the baseline variant that is capable of gun and missile control using one air-engagement channel and two surface-search, TWS channels.
Mk 92 Mod 1/5 are for gun control only. Mod 1 is fitted in the Bear-class cutters, the Pegasus (PHM 1) class (except for the lead ship Pegasus, which was fitted with the Mk 94 prototype), and modern-izedHamilton-classcutters.
Mod 5 is fitted in Saudi Navy Badr and Al-Siddiq small combatant classes.
Mk 92 Mod 2 is combined in PCTTji-class frigates with the STIR radar (Mk 39 antenna on an SPG-60 pedestal) to provide a second missile guidance channel for engaging air targets. Also has two TWS, surface-engagement channels. The STIR system is fitted with the monopulse feed and CWI horns, making it similar to the targeting radar in the CAS radome.
DEVELOPMENT • Original Dutch WM20 series entered service in the 1960s; Mk 92 achieved initial operational capability in 1977. Mod 6 CORT upgrade currently in production. Manufactured by Unisys, Great Neck, New York.
SPECIFICATIONS •
BAND I/J WEIGHTS
above decks: Mod 0/1 1,905 Ib (865 kg); Mod 2 6,318 Ib (2,866 kg)
below decks: Mod 0 9,086 Ib (4,121 kg); Mod 1 5,637 Ib (2,557 kg); Mod 2
15,848 Ib (7,189 kg); Mod 5 7,835 Ib (3,554 kg); Mod 6 24,000 Ib (10,886 kg)
SPG-51
The AN/SPG-51 is a target tracking and illumination radar used with the Tartar/ Standard-MR Surface-to-Air Missile (SAM), in conjunction with the Mk 74 gun and missile fire control system. It was the first operational pulse-Doppler tracking radar.
The antenna is a parabolic dish reflector with offset horn feed. The Mk 74 uses two SPG-51 radar antennas per missile launcher; the antennas are stepped down from the air-search radar that first detects the target. Data goes from the air search radar to the Mk 74 digital fire control computer, which assigns a search pattern to the SPG-51 until the target is acquired.
The radar tracks the target, providing angle and range information to the missile launchers through the fire control computer; the operator can override angle and range tracking computation. Target tracking uses the differences in Doppler shifts in target returns, allowing experienced operators to hear as well as see the target picture.
Embedded I-band antennas in the SPG-51′s reflector illuminate the target for the semiactive radar-homing seekers in the Standard missile.
VARIANTS •
SPG-51A replaced SPG-51′s 2-kW illuminator with 5-kW module, while SPG-51B added velocity tracking using a narrowband Doppler filter.
SPG-51C added automatic acquisition and tracking, surface acquisition and track, horizon-search modes, and improved multiple-target resolution, clutter rejection, and electronic counter-countermeasures. Peak power is up to 30 kW. Updates replaced several vacuum-tube components with solid-state ele-merits and substituted faster-acting, more reliable mount drives. Both the Charles F. Adams (DDG 2) and Brooke (FFG 1) classes operated this variant.
SPG-51D uses a more powerful, dual-channel, frequency agile (four changes per second) transmitter, more effective antenna with five times the gain, instantaneous electronic emission control on command.
DEVELOPMENT •
After development,
the SPG-51 achieved its initial operational capability in 1960. Raytheon Co., Wayland, Massachusetts, manufactured the SPG-51. In addition to Standard-armed guided missile destroyers in the US Navy, Standard-bearing ships in seven other navies use one or two SPG-51 pairs.
SPECIFICATIONS •
BAND G (tracking), I (illumination)
PEAK POWER tracking 81 kW; illumination 5 kW
PULSE WIDTH 2.1-3.2 microsec
PRF surface mode 4,100 Hz; air mode 9,500-17,700 Hz
SYSTEM GAIN tracking 39.5 dB; illumination 45 dB
ANTENNA BEAMWIDTH tracking 1.9° conical scan; illumination 0.9°
ELEVATION -30°-83°
SPG-53
The AN/SPG-53 is a fire control radar for the Mk 68 gunfire control system for use with Mk 42 5-in (127-mm) dual-purpose guns.
The SPG-53 uses a nutating feed in the center of a solid parabolic reflector for conical scanning. After acquiring a target using a 12° spiral scan, the radar switches to a 3° conical scan for target tracking; the transition between scanning modes takes approximately five seconds. Later variants of this radar provide monopulse tracking and clutter cancellation to allow low-elevation angle tracking.
VARIANTS •
SPG-35A operated in Farragut- and Adams-class missile ships. A 1970s program added Radar Signal Processing Equipment (RSPE) that eliminated two of the three operators while speeding up target acquisition and tracking. SPG-53E/F introduced monopulse tracking. The -53E wasn’t deployed because the -53F also offered simulated ECM for training. Many SPG-53As were upgraded to this standard.
SPG-35B equipped four mid-1960s Tartar SAM destroyer conversions, SPG-53C has CWI and is fitted in the Spanish Navy Baleares-class guided-missile escorts, SPG-53D was similar to the -53C and was used in five US Navy Knox-class frigates fitted with Standard SAM missiles.
DEVELOPMENT •
Prototypes developed in the early 1950s, with the first radars going into service in the Forrest Sherman class of all-gun destroyers in 1955. Manufactured by Western Electric.
Few active US ships still carry the SPG-53, but foreign navies operating former Adams-class destroyers and Knox-class frigates have it.
SPECIFICATIONS •
BAND I/J
RANGE 59.2 nm (68.2 mi; 110 km) ACCURACY 30 ft (9.1 m) RESOLUTION 240 ft (73.1 m) PEAK POWER 250 kW PULSE WIDTH 0.25 microsec PRF 1,000 Hz SYSTEM GAIN 39 dB SYSTEM WEIGHT 5,000 lb (2,268 kg) ANTENNA DIAMETER 5 ft (1.52 m) ANTENNA WEIGHT 163 lb (74 kg)
SPG-55
The AN/SPG-55 “searchlight” illumination and guidance radar is fitted in ships armed with the Terrier/Standard-ER, surface-to-air missile, one radar unit per missile rail. These large, heavy assemblies succeeded the AN/SPQ-5 radars. The Mk 76 missile fire control system has progressed through several mods and is deployed in Mod 9 and Mod 10 variants.
The current variant tracks and illuminates targets for the Semiactive Radar (SAR) homing seeker on the Standard-ER. The radar uses a G/H-band pulse tracking radar and I/J-band Continuous-Wave Illuminator (CWI). The radars are mounted as pairs; both reflectors can be energized by the same transmitter, should the other fail.
The 96-in (2.44-m) diameter Cas-segrain antenna has two parabolic reflectors, one in front of the other, the distance between them being spanned by a casing that acts as a hyperbolic reflector. Pulse emissions from the G/H-band four-horn feed in the center of the rear (main) antenna strike the rear of the front antenna, reflect back onto the main antenna, and radiate out through the front reflector, which is polarized to become “invisible” to the beams.
The front dish serves as the parabolic reflector for the Continuous Wave (CW) I/J-band illuminator; at the same time, a broader beam radiates forward from the same feed horn to provide a rear reference signal for the missile’s computer. An auxiliary Custer horn pillbox antenna on the side of the stabilized main antenna mount is used for tracking low, short-range targets such as antiship missiles.
The radar can operate in the presence of heavy jamming using a coast mode or range-rate prediction. The last of the beam-riding Terrier missiles, which required a conical scan with nutating feed, were retired in the late 1980s.
Refits and upgrades that replaced vacuum tubes with digital solid-state circuits greatly improved the SPG-55′s reliability and its resistance and response to ECM and expanded its envelope to include surface targets and low-flying aircraft and missiles. Many passive techniques, including sidelobe canceling, passive angle tracking, and a radar silence mode that
features dummy loading of the transmitter’s signal, counter the jamming target.
The latest SPG-55 OrdAlts (field modification kits) permitted Continuous-Wave Angle Tracking (CWAT) that burns through jammers. To counteract the horizon-level targets, SPG-55s can search the horizon or a given sector, suppress clutter, and track a surface target continuously.
The last principal variants in service were the SPG-55C in the US Bainbridge and Leahy “double-ender” missile cruisers as well as the Italian Vittorio Veneto and Andrea Doria classes. Long Beach and the nine Belknaps, had the -55D New Threat Upgrade (NTU) variant. (The recently retired .Farrago-class guided-missile destroyers have -55Bs.)
DEVELOPMENT •
Prototypes fielded in the late 1950s, with production beginning at Sperry Rand (later Unisys) in Great Neck, New York. Updates and OrdAlts began in the mid-1960s.
SPECIFICATIONS •
BAND G/H (tracking) and I/J (CWI) RANGE 148 nm (172 mi; 276 km); 49.3
nm (56.8 mi; 91.4 km) against 10.8-ft2
(l-m2),Mach 2 target
POWER
peak 1 MW in G/H band
average 5 kW in I/J band
PULSE WIDTH
target acquisition and tracking
26 or 1.6 microsec
tracking 0.1 microsec
(uncompressed or compressed from 12.7 microsec)
PRF
target acquisition and tracking
203-225 Hz tracking 427 Hz SYSTEM GAIN 39 dB (G/H), 47 dB (CWI)
ANTENNA BEAMWIDTH
G/H band: 1.6° I/J band: 0.8°
ANTENNA WEIGHT 12,970 lb (5,883 kg) DIMENSIONS
mount 14 ft 7 in X 23 ft 5 in (4.44m X 7.14m); antenna 8 ft (2.44 m)
SPG-60
The AN/SPG-60 is an automatic, scan-to-acquire, shipboard air target tracking radar that operates with the SPQ-9 in the Mk 86 fire control system and is used primarily to lay the ship’s 5-in (127-mm) guns. It has a relatively high gain and a high Pulse Repetition Frequency (PRF) for precise velocity measurement.
Once a shipboard 2D or 3D search radar (e.g., the SPS^0 or the SPQ-9) designates the target area for the pulse-Doppler monopulse SPG-60 radar, it scans for, acquires, and tracks the target. Although primarily used against air targets, the SPG-60 can also operate in a horizon-search mode. To reduce the inherent range ambiguities of a pulse-Doppler radar, the Mk 86 computer varies the transmitter’s pulse width and very high PRF. The radar can handle range rates of up to Mach 3.
When used for Sea Sparrow or Standard-MR SAM, the SPG-60 transmits a separate continuous-wave injection channel to illuminate the target. A closed-circuit television boresighted through the antenna allows passive tracking; it has a continuously adjustable field of view ranging from 2.1 to 21°. A separate optical sight provides visual fire control and damage assessment.
The SPG-60 is not used with the SPQ-9A and Mk 86 fire control system for the 5-in guns on Ticonderoga (CG 47)-class cruisers (antiair capability on those ships is provided by the Aegis AN/SPY-1 radars). The SPG-60′s antenna mount carries the Separate Target Illumination Radar (STIR) and is fitted in the Oliver Hazard Perry (FFG 7) class to provide two missile control channels for the Mk 92 Mod 2 fire control system.
DEVELOPMENT •
Development began in the late 1960s, with the first prototypes of the Mk 86 delivered to the US Navy in March 1970. Manufactured by Lockheed Electronics Co., Plainfield, New Jersey. In service in several US cruiser and destroyer classes as well as in US Adams- and .FVrry-design ships operating in the Australian, German, and Spanish navies.
SPECIFICATIONS •
BAND I/J RANGE
instrumented: 49.3 nm (56.8 mi; 91.4 km)
detection of 10.8-ft2 (1.0-m2) target: 41.9 nm (48.3 mi; 77.7 km)
CW illumination of 10.8-ft2 (1.0-m2) target: 9.9 nm (11.4 mi; 18.3 km)
PEAK POWER 5.5 kW
PULSE WIDTH 0.27, 1, or 6 microsec PRF 25,000-30,000 Hz
SYSTEM GAIN 41.5 dB
ANTENNA WEIGHT 4,015 lb (1,821 kg) ANTENNA DIAMETER 13 ft 4 in (4.06 m) ANTENNA BEAMWIDTH 1.2° X 1.2°
SPG-62
The AN/SPG-62 is a continuous wave, illumination radar for the Standard SM-2 missile in the Aegis air defense missile system. Three (DDG 51) or four (CG 47) Mk 99 missile control directors trigger the SPG-62′s illumination signal as the Standard missile nears its target, bathing the target in a coded signal that the missile’s semiactive homing seeker tracks until the missile explodes or hits the target.
DEVELOPMENT •
Manufactured by Raytheon in Wayland, Massachusetts, and achieved initial operational capability in 1983 with the Ticonderoga (CG 47). Also fitted inArleighBurke (DDG 51)-class destroyers.
SPECIFICATIONS •
BAND I/J
AVERAGE POWER 10 kW
ANTENNA DIAMETER 7 ft 6 in (2.29 m)
SPQ-9A
The AN/SPQ-9A is a multipurpose US naval radar, operating with the AN/ SPG-60 radar as part of the Mk 86 fire control system. This combination provides surface-search and low-level air coverage (up to 2,000 feet). The radar supports defenses against high-speed (up to Mach 3), low-flying missiles or aircraft, as well as tracking helicopters.
The SPQ-9 radar operates in a high-resolution, pulse-Doppler, track-while-scan mode. The Mk 86 FCS can handle up to 120 targets in the track-while-scan mode, handling two or three surface or low-flying target engagements simultaneously. The system can be integrated with the Naval Tactical Data System (NTDS).
A high scan rate of 60 rpm provides a one-second “data rate” to detect and more accurately track incoming missiles as well as surface targets. 167:1 optical pulse compression extends detection range. The basic SPQ-9 system provides low-altitude air-search (2,000 ft/610 m) and surface-search functions, and is enclosed by a radome; the other adds Identification Friend or Foe (IFF) and extends air coverage to an elevation of 25°.
The SPQ-9A provides pulse-to-pulse frequency agility in a choice of five frequencies to counterjamming and natural clutter, and to allow several radars to operate in a cluster without interfering with one another. Digital Moving Target Indicator (DMTI) processing added under a mid-1980s upgrade removes stationary objects from the target screen, reducing clutter. In addition, the upgrade introduced a Low-Noise Front End (LNFE), which increases effective system gain.
The SPQ-9A includes a separate radar beacon transmitter/receiver for accurate navigation during indirect shore bombardment, when the target is out of view of both the radar and optical sighting systems.
DEVELOPMENT •
Prototypes tested beginning in 1967, with the first prototypes of the entire Mk 86 system being delivered to the US Navy in March 1970. Manufactured by Lockheed Electronics, Plainfield, New Jersey. In service on a variety of US surface combatants, the Tarawa-class amphibious assault ships, and Australian and German Adams-design destroyers.
SPECIFICATIONS •
BAND I/J
RANGE 20 nm (23 mi; 37 km) max; 450
ft (137m) min PEAK POWER 1.2 kW PULSE WIDTH 0.3-16 microsec PRF 3,000 Hz SYSTEM GAIN 37 dB ANTENNA WEIGHT 1,185 lb (537.5 kg)
with radome
ANTENNA DIMENSIONS 7 ft 8>/2 in (2.35
m) wide X 2 ft 6 in (0.762 m) ANTENNA BEAMWIDTH 1.35° X 3°
SPS-10
For decades, the AN/SPS-10 was the standard US Navy surface-search radar. Although considered a horizon-range navigation radar, it routinely detects targets at much greater ranges. Existing SPS-lOs are being replaced by the solid-
state SPS-67 that use the SPS-10′s parabolic cylinder open-mesh antenna.
The original SPS-10 emitted 190-285-
kW pulses. The next three versions used a more powerful 500-kW transmitter. SPS-10E/F versions offer a broader beam-
width of 1.9° X 16°.
DEVELOPMENT •
Began in the early 1950s, with first deliveries in 1953, and
achieved initial operational capability in 1955. Manufactured by Raytheon and GTE. Although long out of production, SPS-
10 radars remain in widespread use.
SPECIFICATIONS •
BAND G (5.45-5.825 GHz)
PEAK POWER 500 kW
PULSE WIDTH 0.25 or 1.3 microsec
PRF 625-650 Hz
SYSTEM GAIN 30 dB
ANTENNA BEAMWIDTH 1.5° X 16°
ANTENNA SCAN RATE 15 rpm
ANTENNA WEIGHT 442 lb (200 kg)
ANTENNA DIMENSIONS
width 10 ft 6 in (3.2 m)
height 6 ft 4 in (1.93 m)
SPS-40
The AN/SPS-40 is a family of long-range air-search and shipboard surveillance radars developed from the AN/SPS-31 and have been in US service since 1961. Although the SPS-40 was developed for use on destroyers, it is now the standard lightweight air-search system for the US Navy.
It replaced the AN/SPS-6 and AN/ SPS-29, and delayed the AN/SPS-49′s introduction into service.
The Lockheed-developed family was replaced by an improved version, designated the SPS-40A, which in turn was replaced by the SPS-40B. Most SPS-40 systems now in use are the SPS-40D, an upgraded -40A that is fully solid-state.
The original SPS-40 had excellent range resolution, using a short transmitted pulse. The system uses a feed horn overslung on an open-mesh parabolic reflector antenna. Radar signals were originally emitted in the Ultra-High Frequency (UHF) band, using pulse compression for very long detection ranges.
Developments that resulted in the SPS-40A included a new broadband transmitter and solid-state receiver changes. Scan rate was a relatively low 6 rpm. Both the SPS-40 and -40A were un-
reliable and had a low Mean Time Between Failure (MTBF) rate. These variants had difficulty spotting air targets closer than the radar’s horizons (e.g., 300 ft/91.4 m to 18 nm/21 mi/3 3 km) when they flew at less than 50,000 ft (15,240 m).
The SPS-40B included an AIMS Identification Friend or Foe (IFF) system, 10 Radio Frequency (RF) operation channels, and a Low Flyer Detection Mode (LFDM). Some versions included a Minimum Range Modification (MRM) system that provided range and bearing data on low-flying aircraft in the SPS-40 and -40A’s blind spot.
Modifications to the LFDM were included in the SPS-40C system that went into service in the early 1970s. The SPS-40C and its improved version, the SPS-40D, are solid-state systems with a 40% increase in reliability and maintainability over the previous SPS-40 versions. In addition, the Two-Dimensional (2D) SPS-40D has automatic target detection capability for use in a shipboard combat system, Digital Moving Target Indicator (DMTI).
DEVELOPMENT •
Derived from the SPS-31, the SPS-40 was first delivered in June 1961. Older SPS-40s were upgraded to the C/D configurations, which use solid-state electronics to increase reliability from about 80 hours MTBF to about 200 hours. SPS-40E used a Westing-house SSTx solid-state transmitter that powers up quickly and is much more reliable. Although envisioned for retrofitting into existing SPS-40 ships, the SPS-40E failed to attractfunding and was canceled.
Manufactured by Lockheed Electronics, Plainfield, NewJersey. In service in many US ships as well as former US Navy ships transferred to other countries.
SPECIFICATIONS •
BAND B (400-450 MHz) PEAK POWER 225 kW; pulse-compressed 200 kW
PULSE WIDTH 3 or 60 microsec, compressed to 1 microsec (or 0.6 micro-sec) in some variants
PRF 278 or 300 Hz
SYSTEM GAIN 21 dB
ANTENNA BEAMWIDTH 11° X 19°
ANTENNA SIDELOBES
horizontal 27 dB vertical 10 dB
ANTENNA SCAN RATE 7.5 or 15 rpm WEIGHT
antenna 1,728 Ib (784 kg) below-decks equipment
3,474 Ib (1,576kg)
SPS-48
The AN/SPS-48 is a Three-Dimensional (3D) FRESCAN (Frequency Scanning) radar used for long-range air search and for providing data to the Standard SM-2 series of medium- and long-range SAMs. The SPS-48 design eliminated the earlier SPS-39/42′s mechanical stabilizer base, which was a principal source of weight, bulk, and equipment complexity.
The FRESCAN technique gives the system increased range and a high data rate that improve the probability of detecting a target. Using changes in frequency to steer the beam in elevation, the radar emits nine pulses of three microseconds each for a 6° elevation coverage. Each successive pulse stream shifts upward, providing coverage (in the earlier variants) from 0° to 45°. An antijamming mode transmits the signal in a single beam for 27 microseconds; processing compresses the return to three microseconds.
When the SPS^8 and SPS-48Awere upgraded with Automatic Detection and Tracking (ADT) features and a Moving Target Indicator (MTI) capability, they were redesignated the SPS-48C. The SPS-48E encompasses elevation coverage of 0°—65°, has fewer components, lower sidelobes for greater ECM resistance, and better small-target performance.
DEVELOPMENT
• Development began in 1959 with the radar achieving initial operational capabilities in 1962 (SPS-48), 1968 (SPS-48A), 1974 (SPS-48C), and
1983 (SPS-48E). The first SPS-48A production set was deployed on the cruiser Warden (CG 18) in March 1965; the Biddle (CG 34) was first with the -48E, completing installation in July 1987.
Under the New Threat Upgrade
(NTU) program, the SPS-48E was fitted to all cruisers in the Leahy, Belknap, California, and Virginia classes as well as the cruiser Long Beach and the Kidd-c\a.ss guided-missile destroyers. Manufactured by ITT Gilfillan in Van Nuys, California.
Plans in the 1980s to retrofit 12 aircraft carriers with the SPS-48E ran afoul of the $75 million per carrier cost ($12 million for the radar itself), and only the Kitty
Hawk (CV 63) and Constellation (CV 64)
actually received them.
SPECIFICATIONS • BAND E/F (2.9-3.1 GHz) RANGE 220 nm (253 mi; 408 km); low angle 230 nm (265 mi; 426 km)
accuracy 690 ft (210 m)
ELEVATION COVERAGE
SPS-48C: +07+45° SPS^8E: +0°/+65°
MAXIMUM ALTITUDE 100,000 ft
(30,480 m)
ELEVATION ACCURACY !/6° RESOLUTION IN RANGE 1,500 ft (457 m), in elevation 2°
POWER
peak 2.2 MW
average SPS-48C: 15 kW SPS^8E: 35 kW
PULSE WIDTH 3 microsec
PRF 1,250-2,000 Hz
SYSTEM GAIN 38.5 dB WEIGHT (SPS-48C)
total .system 22,000 Ib (9,979 kg) antenna 4,500 Ib (2,041 kg)
ANTENNA BEAMWIDTH 1.5° X 1.6° ANTENNA SIDELOBES
SPS-48C: -23 dB SPS^8E: -33 dB
ANTENNA SCAN RATE 7.5 Or 15 rpm ANTENNA WIDTH
SPS-48C: 16 ft 2 in (4.93 m) SPS-48E: 18 ft (5.49 m)
ANTENNA HEIGHT
SPS-48C: 17 ft 6 in (5.33m) SPS-48E: 18 ft (5.49 m)
SPS-49
The AN/SPS-49 is said to be the most effective rotating, Two-Dimensional (2D) search radar in US Navy service. Although developed in the 1960s, it did not enter service until the first Oliver Hazard P«?rry-class frigate was commissioned in 1977. In the next 15 years, the SPS-49 became the Navy’s principal 2D air-search radar and has been produced in several variations.
An underslung, fan-shaped horn feeds the open-mesh, orange-peel parabolic antenna. A klystron amplifier maintains pulse-to-pulse stability of signal amplification while mechanical stabilization steadies the antenna.
A significant update entered service as the SPS-49 (V) 5. Improvement includes Automatic Detection Tracking (ADT), digital pulse-Doppler processing, Constant False-Alarm Rate (GEAR) processing, and clutter mapping. The system also uses frequency agility, four-loop Coherent Sidelobe Canceler (CLSC), an anti-chaff mode, and up-spotting (elevating the main beam) for better Electronic Counter-Countermeasures (ECCM) capability. In its (V)5 form, the radar’s Mean Time Between Failure (MTBF) is a relatively healthy 600 hours.
VARIANTS •
SPS-49 (V)l designates
Perry-class ship installations.
SPS-49 (V) 2 replaces earlier 2D air-search radars in New Threat Upgrade (NTU) refit of cruisers and destroyers.
SPS-49 (V) 3 fitted in Canadian ships
and has embedded ADT system.
SPS-49 (V) 6 designates installations in
Ticonderoga-class cruisers.
DEVELOPMENT •
The SPS-49 was evaluated in 1965 on board the experimental destroyer Gyatt (DDG 1/DD 712) but first became operational only in 1977. It is the principal 2D search radar in US service. Australian and Spanish Perry-design frigates also operate the SPS-49. Manufactured by Raytheon, Wayland, Massachusetts.
In 1990, the Navy canceled the SPS-49 SSTx with solid-state transmitter then under development by Westinghouse.
SPECIFICATIONS •
BAND C (851-942 MHz)
POWER
peak 280 kW (V) 1, 360 kW
(V)5
average 10 kW (V) 1 -4, 13 kW (V)5 ,
PULSE WIDTH 125 microsec (with 83:1
compression) or 2 microsec PRF 280, 800, or 1,000 Hz
SYSTEM GAIN 29 dB RANGE ACCURACY 0.03 nm AZIMUTH ACCURACY 0.5°
SYSTEM WEIGHT BELOW DECKS SPS-49(V): 13,791 Ib (6,255 kg) SPS-49(V)5: 14,004 Ib (6,325 kg)
ANTENNA BEAMWIDTH 3.4° X 30° COSC-
cant2 ANTENNA WEIGHT
SPS49 (V)l: 3,210 Ib (1,456 kg) SPS-49(V)5: 3,165 Ib (1,425 kg)
ANTENNA DIMENSIONS
width 24 ft (7.3m)
height 14 ft 3 in (4.3 m)
SPS-52
The AN/SPS-52 is a US three-
dimensional air-search radar with electronic Frequency Scanning (FRESCAN) in elevation and mechanical rotation of the antenna in azimuth. It is an improved
AN/SPS-39 (the first FRESCAN radar)
that uses a similar klystron transmitter, a planar-array antenna, digital beam stabilization, parametric amplifier, and has a longer range. It is smaller and less capable than the AN/SPS-48.
For short-range tracking, a high-data-rate mode (15 rpm scan rate) supplies a high-PRF signal. The radar also uses high-angle, medium-range detection and tracking and long-range tracking; the -52B and C also have a Moving Target Indicator (MTI) mode that ignores clutter. Maximum range is 60 nm (111 km) against small, high-speed targets, and out to much greater distances against large, high-flying aircraft. Maximum viewing elevation is 42° with limited angles of 13° in the short and medium ranges, 4.5° in the long range.
The antenna is the AN/SPA-72B planar array, tilted back at an angle of 25° from the vertical, allowing coverage to a high angle of elevation. 60 stacked linear arrays, each with 98 radiating slots, make up the antenna and are energized by a deep serpentine feed along one vertical edge.
The SPS-52B introduced MTI clutter
rejection for better low-altitude performance and the AN/UYK-15 computer. Peak power is 900 kW, low power level is 14.4 kW. The SPS-52C added Automatic Target Detection (ATD) that allows operation with a computerized combat system and an increase in claimed MTBF to 216 hours.
DEVELOPMENT •
Development began in 1963 for the SPS-52 and 1973 for the
SPS-52C, with the SPS-52C entering service in the late 1970s. Manufactured by Hughes Aircraft Co., Fullerton, California. The SPS-52 has been installed in several US warship classes (primarily the Adams-class destroyers and the Tarawa and Wasp amphibious assault ships). Australian and German Adams-design ships also use the SPS-52 as well as several Italian, Japanese, and Spanish ship classes. The sets in the older ships are being
modified to the current SPS-52C configuration to improve reliability and performance.
SPECIFICATIONS •
BAND E/F (2.91-3.1005 GHz)
RANGE
short, high-data-rate
60 nm (69 mi; 111 km) high-angle 160 nm (184 mi; 296 km)
long 240-245 nm (276-282
mi; 444-454 km)
PEAK POWER 1 MW
LOW POWER MODE 16 kW
PULSE WIDTH 2.5, 4.6, or 10 microsec SCAN RATE 15, 10, or 7.5 rpm
SYSTEM GAIN 39.5 dB WEIGHT
below-decks equipment
SPS-52B: 15,934 Ib (7,228
SPS-52C: 14,040 Ib (6,368
kg)
ANTENNA WEIGHT 3,200 Ib (1,451 kg) ANTENNA DIMENSIONS
width 13 ft 9 in (4.19m)
13 ft 11 in (4.24m)
SPS-53/SPS-60
This high-resolution surface search and navigation radar uses a 5-ft (1.5-m) slotted array antenna. The earlier SPS-53 has vacuum tubes, the SPS-60 solid-state circuitry. The chief difference among variants is the width (5 ft or 8 ft/1.52 m or 2.44 m) and height of the antenna.
The SPS-60 has solid-state components and uses a standard 8-ft (2.44-m) antenna.
DEVELOPMENT •
Development began in the early 1960s, with the radar achieving initial operational capability in 1967. In some ships, it replaced the SPS-5. Manufactured by Sperry Rand (later Unisys), Great Neck, New York. Remains in service on auxiliaries such as the Sacramento and Wichita fast support ships.
SPECIFICATIONS •
BAND I/J
PEAK POWER 40 kW
PULSE WIDTH 0.5 or 1.0 microsec
PRF 750 or 1,500 Hz
BEAMWIDTH 1.6° X 20° SCAN RATE 15 rpm
SPS-55
This I-band surface search and navigation radar replaces the widely used C-band SPS-10. Because it operates in the I-band, the SPS-55 avoids interfering with C-band missile target trackers. It also tracks low-flying aircraft and helicopters.
The antenna has two end-fed slotted waveguide arrays arranged back-to-back and squint-compensated. Antenna polarization can be either linear or circular, the latter to screen out rain echoes. Side-lobes are approximately the same regardless of polarization. It is fed by a coaxial magnetron that generates two different pulse widths. At the longer (1.0 microsecond) pulse width, signals fainter than -102 dB below output can be detected.
The receiver is an image-suppression mixer preamplifier that has Automatic Frequency Control (AFC), Fast Time Control (FTC), Sensitivity Time Control (STC), and logarithmic/linear-logarithmic detection processing. Sector width can range between 10° and 180°, and coverage can start at any point around the horizon.
All components except the magnetron are solid-state, which contributes to higher Mean Time Between Failures (MTBF) and lower Mean Time to Repair
(MTTR). Required MTBF was 500 hours;
test results showed an MTBF of 1,200 hours.
VARIANTS •
SPS-502 is a Canadian-built variant 95% compatible with SPS-55, but operating in the G-band and using the SPS-10B antenna truncated paraboloid antenna. The receiver has low-
noise GAS Field-Effect Transistor (FET) RF amplifier ahead of the mixer preamp. Most characteristics are identical except: vertical antenna beamwidth is 12.5°, and noise figure is less than 5 dB.
DEVELOPMENT •
Developed by Raytheon, but produced by Cardion Electronics (part ofFerranti International) in Woodbury, New York. The first production contract was placed in 1971. Several recent surface combatant classes as well as the Avenger-c\ass minesweepers operate the SPS-55.
SPECIFICATIONS •
BAND I (9.05-10 GHz)
PEAK POWER 130 kW FULSEWIDTHS l.Omicrosec ( + /—0.1
microsec) or 0.12 microsec (+/—0.03
microsec)
PRF 750 or 2,250 Hz
MINIMUM RANGE long pulse 900 ft (274 m); short pulse 150 ft (46 m)
RESOLUTION long pulse 650 ft (198 m); short pulse 75 ft (23 m)
RECEIVER BANDWIDTH long pulse 1.2 MHz (+/-0.25 MHz); short pulse 10.0 MHz (+/-1.0MHz)
RECEIVER NOISE FIGURE 10.5 dB maximum
ANTENNA SCAN RATE 16 rpm ANTENNA GAIN linear polarization
30 dB minimum at 9.5 GHz
circular polarization
no more than 4 dB less than linear ANTENNA BEAMWIDTH 1.5° X 20° ANTENNA SIDELOBES linear polarization
-26° within 10°, -30°
outside
circular polarization
-25.5° within 10°, -30° outside
SPS-59 (LN-66)
AN/SPS-59 is the US Navy designation for the LN-66 short-range navigation radar that is usually fitted in surface ships as a secondary, close-range navigation radar.
DEVELOPMENT • Manufactured by Marconi of Canada. In service in many US Navy ships as well as in the SH-2F LAMPS I ASW helicopter.
SPECIFICATIONS •
BAND I/J
PEAK POWER 10 kW
PULSE WIDTH 0.05 or 0.5 microsec SPS-63
The AN/SPS-63 is a US license-built version of the Italian 3RM-20N surface-search radar. The antenna is a horizontally polarized slotted waveguide that produces a vertical beam pattern of 26°, shaped to 40°. The 20-kW transmitter has four Pulse Repetition Frequencies (PRF) and four pulse lengths.
DEVELOPMENT •
Manufactured by the US firm Dynell Electronics under license from the Italian company SMA of Florence, Italy, to fit in the Pegasus-class patrol hydrofoil craft.
SPECIFICATIONS •
BAND I {9.375 GHz) RANGE 40 nm (46 mi; 74 km) instrumented, 60 ft (18.3 m) minimum BEARING ACCURACY 1°; resolution 1.2°
PEAK POWER 20 kW
PULSE WIDTH 0.05, 0.15, 0.5, or 1.5 mi-crosec
PRF 6,000, 3,000, 1,500, or 750 Hz
SYSTEM WEIGHT 217 lb (98 kg)
SCAN RATE 25 rpm SPS-64(V)
The AN/SPS-64(V) is a modular surface
search and navigation radar that can
operate in either F- or I-band. Depending on the variant, an SPS-64 set will combine elements of four I-band and one F-band slotted-waveguide antennas as well as three transmitter power levels emitting in either band.
In the F-band, the range is approximately 50 nm (92.6 km), and the radar can automatically track 20 targets simultaneously. I-band sets are used for navigation and feature higher resolution at a shorter range. RAYPATH, which plots and displays surface tracks, and RAYCAS, which tracks air targets, are also part of the system.
The commercial name for this radar is Pathfinder, and Raytheon designations include RM 1220 and RM 1620.
VARIANTS •
SPS-64(V) 1/7/8/9: One 20-kW I-band transmitter, 6-ft (1.83-m) I-band antenna; Coast Guard; SPS-64 (V) 5 is similar to
(V)l for US Army ships; SPS-64 (V) 11 is (V) 1 with RAYPATH; Coast Guard.
SPS-64(V)2: As (V)l, but with two 20-kW I-band transmitters and three displays; SPS-64 (V) 3 has two displays; SPS-64(V)10 has two 6-ft (1.83-m) I-band antennas.
SPS-64 (V) 4: One each of 20-kW I-band,
60-kW F-band transmitter, 6-ft (1.83-m)
I-band, and 12-ft (3.66-m) F-band antenna; SPS-64(V)6 has 50-kW I-band transmitter and RAYCAS; Coast Guard (US Navy version is (V)15). SPS-64(V)16 is (V)6 with RAYPATH; US Army. SPS-64(V)18 is (V)15 with 9-ft (2.74-m) antenna.
SPS-64(V) 12/13/14: As (V)5, but with 10-kW transmitter, (V)14 in radome; US
Army.
SPS-64 (V) 17: 60-kW F-band transmitter, 12-ft (3.66-m) antenna, RAYPATH; US Army
DEVELOPMENT •
Manufactured by
Raytheon Co., Wayland, Massachusetts. Introduced in the early 1980s in US Navy ships and is the standard Coast Guard
surface-search/navigation radar. Some US Army ships and craft also operate the radar, as do an assortment of foreign naval ships.
SPECIFICATIONS •
BAND F (3.025-3.075 GHz) and/or I
(9.345-9.405GHz) PEAK POWER F band 60 kW; I band 20
or 50 kW
PULSE WIDTHS 0.06, 0.5, or 1.0 microseconds PRF 3,600, 1,800, or 900 Hz
ANTENNA SCAN RATE 33 rpm
ANTENNA BEAMW1DTH (HORIZONTAL X VERTICAL) F band: 2° x 25°
I band: 0.7°, 0.9°, 1.25°, or 1.9° x 22°
ANTENNA WEIGHT 6-ft 140 lb (63.5 kg);
12-ft 332 Ib (150.6 kg)
SYSTEM GAIN 28 dB
SPS-58/SPS-65(V)
The AN/SPS-58/65 is a pulse-Doppler
radar specifically adopted to detect anti-ship cruise missiles and for target acquisition for the Sea Sparrow point defense missile system.
Early variants had a 16-foot elliptical antenna, but later radars use an AN/ SPS-10 antenna that had its original feed horn replaced by a dual-feed waveguide horn. The SPS-58 stands alone and, in some versions, has its own display; it uses a klystron transmitter. Taiwan Navy ships use the SPS-58 as the missile detector for the H930 combat system. Can apply both Automatic Target Detection (ATD) for a direct link to the H930 and Moving Target Indicator (MTI) processing to screen out clutter.
SPS-65 versions have a solid-state transmitter and feed their data into the ship’s
Naval Tactical Data System (NTDS),
which combines the information with other sensor data and puts it up on integrated displays.
SPS-65 (V) 1 was designed as a detector rather than an engagement radar. SPS-65 (V) 2 adds autotracking (but operator must key it), a Fire Control Interface Group (FCIG), track history, target cen-troids (several previous recorded target positions rationalized into one), NTDS symbology, and output suitable for either gun or missile systems. SPS-65 (V)ER operates in three modes using a more powerful transmitter, improved signal processing that includes digital MTI, stretch-pulsed transmission and pulse compression, and burst-to-burst frequency agility. The SPS-65 (V) 1 has a specified Mean Time Between Failure
(MTBF) of 400 hours.
DEVELOPMENT •
Development began in early 1967 after studies showed that existing radars would not detect low-flying missiles quickly enough. The sinking of the Israeli destroyer Eilat in December 1967 by an antiship missile gave an extra impetus to the project. Six different ideas or designs were considered before the Navy chose the Siemens MPDR-45 to be developed into the SPS-58 by Westing-house Electric Corp., Baltimore, Maryland.
Those US ships fitted with SPS-58s saw
them replaced by SPS-65 (V) sets in the 1980s. In service in US aircraft carriers and command ships as well as in Taiwanese destroyers and ex-US Knox-clzss frigates in other navies.
SPECIFICATIONS •
BAND D (1.215-1.365 GHz) RANGE (detection of 10.8-ft2/l-m2 target)
-65(V) 1/2: 23 nm (26.5 mi; 42.6 km) -65(V)ER: 61 nm (70.2 mi; 113 km)
RANGE ACCURACY
-65 (V) 1/2: 1,500ft (457m) -65(V)ER:608ft (185m)
RANGE RESOLUTION 3,000 ft (914 m) ELEVATION COVERAGE
-65(V)l/2: 16° -65(V)ER:30°
AZIMUTH ACCURACY 0.5° AZIMUTH RESOLUTION
-65{V)172:5.8° -65(V)ER: 3.5°
PEAK POWER
-65 (V) 1/2: 12 kW -65(V)ER: 25 kW
AVERAGE POWER
-65 (V) 1/2: 260 W
-65(V)ER: 1.200W PULSE WIDTH 7 microsec PRF -65 (V) 1/2 2,315 or 3,064 Hz, plus 300-625Hzin-65(V)ER
SYSTEM GAIN 23 dB
MTI IMPROVEMENT FACTOR 60 dB
SYSTEM WEIGHT, SPS-65 1,594 lb (723 kg)
ANTENNA WEIGHT, SPS-65 439 lb (199
kg)
ANTENNA BEAMWIDTH 3°
SCAN RATE 20 rpm (plus 10 rpm in (V)ER)
SPS-67(V)
The AN/SPS-67 naval surface search and navigation radar was developed as a successor to the long-serving AN/SPS-10 radar. Using the SPS-10 antenna, the SPS-67(V) replaces the vacuum-tube electronics with solid-state Standard/ Electronic Modules (SEM) vacuum tube technology to simplify repair and maintenance.
A digital noise suppressor and a very short-pulse mode improve performance, especially resolution of small targets at close range. This is in addition to the two existing SPS-10 modes. The (V)2 replaces the open-mesh, truncated paraboloid antenna with a linear array. The (V)3 has an add-on unit that provides for integration with the SYS-1 integrated automatic detection and tracking system, as well as providing automatic target detection and digital moving target indication.
DEVELOPMENT •
Prototyping began in the 1970s, the SPS-67 achieving initial operational capability in 1982. Manufactured by Norden Systems, United Technologies Corp. The new antenna system, also built by Norden, was first tested in 1983.
Several surface combatant classes have been refitted with the SPS-67; the Arleigh Burke-class destroyers are receiving them during construction. In addition, later Nimitz-c\a.$s carriers use the SPS-67, as do new amphibious and auxiliary ships.
SPECIFICATIONS *
BAND C
PULSE WIDTHS 1, 0.25, or 0.10 microsec PRF 750, 1,200, or 2,400 Hz SCAN RATE 15 or 30 rpm
SPY-1 Aegis
The AN/SPY-1 multifunction, phased-array radar serves the Aegis Antiair Warfare (AAW) weapons system, which is composed of the SPY-1, a Command and Decision (C&D) element, fire control system, consoles and large-screen displays, air-search and fire control radars, missile launchers, and the RIM-66 Standard-MR and -ER antiaircraft missiles.
Aegis is certainly the most expensive shipboard sensor suite ever installed, and it has been criticized for its expense and for perceived shortcomings in service. Moreover, it is an electromagnetic beacon of prodigious size, beckoning anti-radar weapons launched from far-off platforms.
Nevertheless, as a fleet defense hub, the system provides far more capability than any other combination of systems. Moreover, the system has such signal processing power and range that it is being developed as a mobile Anti-Tactical Ballistic Missile (ATBM) system.
Most visible of all of these elements are the four octagonal fixed-array an-
COMBAT EXPERIENCE •
While providing gunfire support for the US Marines stationed in Beirut in 1983, the USS Ticonderoga (CG 47) used the SPY-1 radar to guard against suicide aircraft or small craft. Although most observers contended that the coverage was complete, a destroyer skipper claimed that the Aegis radar failed to pick up a Cessna light aircraft that was headed for the task force. The destroyer Tatnall’s crew tracked the plane visually until it came within range of the destroyer’s guns, while the Aegis radar allegedly never “saw” it.
On July 3, 1988, the Vincennes’ (CG 49) SPY-1A detected a target that had just taken off from Bandar Abbas airfield in Iran. The Vincennes’ captain, relying on SPY-1A data as well as IFF and unsuccessful attempts to communicate with the aircraft, launched 2 Standard-MR SM-2
missiles at the target. One destroyed the aircraft, killing the 290 passengers and crew on board the misidentified Airbus A300 commercial airliner.
11 different Ticonderoga-class cruisers were deployed in Operations Desert
Shield/Desert Storm in 1990-91.
SPECIFICATIONS •
BAND F (3.1-3.5 GHz)
POWER
peak 4-6 MW
average 58 kW PULSE WIDTH 6.4, 12.7, 25.4, or 51 micros ec
PULSE COMPRESSION RATIO 128:1
BANDWIDTH sustained coherent 10 MHz; instantaneous 40 MHz
SYSTEM SCAN RATE 12 rpm air coverage; 1 rpm at the horizon
SYSTEM GAIN 42 dB WEIGHT
above decks, per face: SPY-1A 13,030 Ib (5,910 kg); SPY-IB 7,900 Ib (3,583 kg)
below decks: SPY-1A 131,584 Ib
(59,686 kg)
ANTENNA BEAM WIDTH 1.7° X 1.7°
VPS-2
The AN/VPS-2 is a coherent pulse-Doppler range-only radar built into the Spanish Meroka naval Close-in Weapons
System (CIWS) and the US Army’s M163A2 self-propelled and M167A2-
towed Vulcan Air Defense Guns (VADS). The VPS-2 antenna is mounted on the turret and moves with the barrel and sight mounts. The optical sight can be laid independently.
The radar operates autonomously to provide tracking of targets and the angular tracking rate. Moving Target Indicator (MTI) processing eliminates clutter. An automatic search and lock-on mode places the optical sight on the target for the gunner. Computation of the radar-measured range and range rate predicts future target position and adjusts the gun accordingly.
The Meroka CIWS uses the VPS-2
matched with the Alenia RAN-12L/X search radar through the Alenia PDS-10 tactical-data console.
DEVELOPMENT •
Initial operational capability in the late 1960s. Manufactured by Lockheed Electronics Co., Plain-field, New Jersey. Shipboard use is confined to the Spanish Perry-design frigates to support the Meroka.
SPECIFICATIONS •
BAND I (9,200-9,500 MHz; 6 crystal-controlled frequencies) SEARCH RANGE 2.7 nm (3.1 mi; 5 km)
TARGET TRACKING 49-1,017 ft/sec
(15-310 m/sec) PEAK POWER 1.4 kW (average 10 watts) ANTENNA BEAMWiDTH 4° conical beam SUBCLUTTER VISIBILITY 40 dB or better tennas mounted on superstructure faces, each measuring 12 ft 6 in (3.81 m) across. Each antenna is subdivided into 140 array modules of 32 radiating elements each; actual number of transmitting elements is 4,096 and receiving elements, 4,352. Each antenna covers a 110° arc to provide full ,360° coverage with some overlap.
Aegis system computers process target track information and provide beam steering. Hundreds of targets can be acquired and identified simultaneously out to ranges of some 250 nm (288 mi; 463 km). The system provides terminal guidance for up to 20 missiles at one time through the associated Raytheon Mk 99 Standard SM-1/2 missile directors.
The Mk 1 C&D element can be programmed to select an appropriate and automatic response to any threat by any weapons system; these are called doctrine statements and are placed in a file until called by a ship’s officer. During intense engagements, the combat system will handle most of the interceptions or other responses automatically. As we note below under Combat Experience, this is not immune to disastrous misuse.
Later Aegis ships fitted with the SPY-IB Baseline 4 have AN/UYK-43 computers and use the Advanced Combat Direction System (ACDS). The computers also run much faster and can maintain many more track files simultaneously.
Four Hughes AN/UYA-4 or -21 Large-
Screen Displays (LSD), each measuring 3 ft 6 in (1.07 m) square, project processed information. The four LSDs can display
ASW, AAW, and ASuW (Antisurface
[ship] Warfare) information. Two sets of consoles face the LSD and five Automated Status Boards (ASTAB) perch
above each pair of LSDs.
The SPY-l’s ability to defeat ECM includes frequency diversity and jamming detection, which leads it to shift to frequencies that show less interference. Digital signal processing techniques counter or suppressjamming as well as sea clutter,
allowing the system to spot sea-skimming missiles more easily.
VARIANTS •
SPY-IB is a production version built for Princeton (CG 59) and later ships with upgraded antennae, improved transmitter with double-duty cycle and signal processor for increased effectiveness against low-flying and small radar-cross-section missiles, and enhanced ECM resistance including reduction of sidelobes by 15 dB.
SPY-ID is the single-deckhouse version in the Arleigh Burke class with two UY21 displays, three illuminators.
DEVELOPMENT •
Development of the Aegis SPY-1 began in the late 1960s as a successor to the canceled Typhon system. The SPY-1 (one radar “face”) began operation at the RCA development facility in Moorestown, New Jersey, in 1973, followed a year later by a single “face” being installed in the missile test ship Norton Sound (AVM 1). Lockheed Martin’s Electronics Division at Moores-town produces the Aegis system, which achieved initial operational capability in Ticonderoga (CG 47) in 1983. LM (formerly GE) is prime contractor for the Aegis weapons system and “design agent” for the more comprehensive Aegis combat system.
A Unisys-Westinghouse team qualified in 1986 as the second source for the SPY-ID single-deckhouse version fitted in the Arleigh Burke-class destroyers, but fell victim to a March 1990 cancellation of plans to procure from two contractors.
US support of the Japanese Aegis destroyer program aroused significant criticism in Congress as well as in Japan. Concerns focused on the transfer of sensitive technology as well as the great cost. Despite the opposition, the program proceeded, and the first of four Japanese Kongou~c\a.ss Aegis ships entered service
in March 1993.
