AN/SPG-55B Radar

AN/SPG-55B Radar (HM2F9N)

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N 39° 11.758', W 76° 41.056'

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The US Navy's AN/SPG-55 is a tracking/illumination radar for the beam riding Terrier and semi-active homing RIM-67 Standard missiles. It was a major component of the MK76 Fire Control System used in fleet and area protection. The Navy deployed early variants in the mid 1950's and the system's final deployment was in Operation Desert Storm in the early 1990's.

The AN/SPG-55 included a C-band (5 GHz) tracking pulse radar and a X-band (10GHz) CW radar for guiding Terrier and SM-2 missiles and for CW Doppler tracking. An 8 foot parabolic antenna was used for both the C-band and X-band transmitters and the C-band pulse receiver. Separate antennas were used for the X-Band CW functions and side lobe receivers. This system was effective in the presence of electronic countermeasures.

Terrier Ships carried a pair of AN/SPG-55 radars located on one or both ends of the ship. Either radar could independently complete the mission.

The antenna system seen here was installed on a rooftop location at JHU-Applied Physics Laboratory to develop improvements in support of the air defense mission. these developments included the addition of pulse compression, Doppler techniques and the addition of communication waveforms as the Terrier missiles evolved and became Standard Missile. The radar was first

manufactured by Sperry Gyroscope.

The RIM-2 Terrier was a two-stage medium-range naval surface-to-air missile (SAM), and was among the earliest surface-to-air missiles to equip United States Navy ships. The RIM-67 Standard ER is an extended range SAM and anti ship missile which replaced earlier missiles including the terrier. Both used semi-active homing on CW energy from the SPG-55B.

Beam-riding is a technique of directing a missile to its target by means of radar. An antenna directs a narrow radar beam at the target. A missile is launched and "gathered" by the radar beam when it flies into it. The missile then follows beam while the antenna keeps the beam pointing at the target. The missile "rides" the beam to the target.
HM NumberHM2F9N
Placed ByNational Electronics Museum
Marker ConditionNo reports yet
Date Added Saturday, March 30th, 2019 at 11:01pm PDT -07:00
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Locationbig map
UTM (WGS84 Datum)18S E 354555 N 4339874
Decimal Degrees39.19596667, -76.68426667
Degrees and Decimal MinutesN 39° 11.758', W 76° 41.056'
Degrees, Minutes and Seconds39° 11' 45.48" N, 76° 41' 3.3599999999998" W
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Which side of the road?Marker is on the right when traveling East
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