Linthicum Heights in Anne Arundel County, Maryland — The American Northeast (Mid-Atlantic)
AN/SPG-55B Radar
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
this page online
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.
Erected by National Electronics Museum.
Topics. This historical marker is listed in these topic lists: Air & Space • War, 1st Iraq & Desert Storm • War, Cold • Waterways & Vessels. A significant historical year for this entry is 1950.
Location. Marker has been reported missing. It was located near 39° 11.758′ N, 76° 41.056′ W. Marker was in Linthicum Heights, Maryland, in Anne Arundel County. It was on Elm Road east of West Nursery Road
Regionally, this marker was in Maryland’s Baltimore Metro Region. It was also in the American Mid-Atlantic. Globally, it was in the North Atlantic Region, North America, the Western Hemisphere, the Western World, and the Anglosphere. Historically, it found itself in what was once one of the original Thirteen Colonies and also the Antebellum South.
Other nearby markers. At least 8 other markers are within 2 miles of this location, measured as the crow flies: Stoney Run Train Station (approx. 0.9 miles away); Elkridge Furnace Inn (approx. 1.6 miles away); Elkridge Landing (approx. 1.7 miles away); a different marker also named Elkridge Landing (approx. 1.7 miles away); Linthicum Heights (approx. 1.8 miles away); Herman F. Prehn (approx. 1.8 miles away); In Honor of Those Who Served (approx. 1.8 miles away); Holly Run Church (approx. 1.9 miles away). Touch for a list and map of all markers in Linthicum Heights.
Other markers no longer nearby. SCR-270 Radar Antenna (was a few steps from this marker but has been confirmed missing); TPS-43 (was a few steps from this marker but has been confirmed missing); Nike Ajax (was within shouting distance of this marker but has been confirmed missing); XAF Radar Antenna (was about 300 feet away, measured in a direct line but has been confirmed missing); a different marker also named Elkridge Furnace Inn (was approx. 1.6 miles away but has been replaced with another marker
Photographed by Adam Margolis, December 19, 2022
3. AN/SPG-55B Radar Marker
The marker can be seen to the right of the radar.
Photographed by Adam Margolis, December 19, 2022
4. AN/SPG-55B Radar
Credits. This page was last revised on September 21, 2024. It was originally submitted on March 31, 2019, by Devry Becker Jones of Washington, District of Columbia. This page has been viewed 2,208 times since then and 161 times this year. Photos: 1, 2. submitted on March 31, 2019, by Devry Becker Jones of Washington, District of Columbia. 3, 4. submitted on March 21, 2023, by Adam Margolis of Mission Viejo, California.
