The XAF was an experimental radar set constructed in 1938, which survived World War II as a historical artifact, and is now placed on exhibit at the National Electronics Museum, located in Linthicum, Maryland.
The XAF—an experimental radar set that resulted from several years' technical progress by the Naval Research Laboratory (NRL)—was constructed in 1938, following a late February decision to experimentally install a radar set on a major warship. Operating at 200 MHz (1.5 meter wavelength) at a power of 15 kilowatts, the XAF featured a "bedspring"-like antenna about 17 feet square. This was mounted in a rotating yoke that allowed it to scan around the horizon, and to elevate to keep the radio beam parallel to the surface of the water when the ship rolled. This large antenna and yoke had to be strong enough for sea service, while remaining as light as possible to avoid excessive topside weight. Accordingly, the Brewster Aeronautical Corporation (then also building the Navy's first monoplane carrier fighter, the F2A "Buffalo"), was given the job of fabricating a suitable duralumin structure. The XAF's transmitter, receiver and other equipment were fabricated by the NRL.
When development and construction were complete, the XAF was installed on the battleship New York. This work, with the antenna mounted atop the pilothouse (displacing a large optical rangefinder, which was moved to the top of the ship's No. 2 14-inch gun turret) was completed in December 1938. During nearly three months of constant operation, averaging almost twenty hours daily as New York participated in winter maneuvers and battle practice in the Caribbean, the XAF's performance and reliability exceeded expectations. It detected aircraft up to 100 nautical miles (nm) away and ships out to 15 nm. The radar was also employed for navigation and in gunnery practice, giving very accurate range and azimuth direction, allowing for accurate targeting of enemy vessels and detection of nearby land or obstructions even at night or in the fog.
At the conclusion of these tests, New York's Commanding Officer recommended installation of radar in all aircraft carriers (whose huge cost, military value and vulnerability to surprise air attack was very well understood), while the Commander of the Atlantic Squadron commented "The XAF equipment is one of the most important military developments since the advent of radio ...". Later in 1939, the XAF was reengineered and placed in production by the Radio Corporation of America (RCA). Designated CXAM, six of these production models were delivered in 1940 and installed on the aircraft carrier Yorktown, the battleship California, and four cruisers. An improved version, CXAM-1, with a simplified antenna, was produced in greater numbers. By the time the United States entered World War II in December 1941, the use of radar in the U.S. Navy was rapidly expanding.
The XAF radar's antenna survived World War II as a historic artifact. For several decades in the middle and later Twentieth Century it was exhibited in Willard Park, close to the Washington Navy Yard's waterfront. However, the outdoor environment contributed to serious deterioration in the antenna's condition, and it was placed in storage in the mid-1990s. In May 2008 it was loaned to the Historical Electronics Museum, located in Linthicum, Maryland, where it was again placed on public exhibit. [1]
The Iowa class was a class of six fast battleships ordered by the United States Navy in 1939 and 1940. They were initially intended to intercept fast capital ships such as the Japanese Kongō class and serve as the "fast wing" of the U.S. battle line. The Iowa class was designed to meet the Second London Naval Treaty's "escalator clause" limit of 45,000-long-ton (45,700 t) standard displacement. Beginning in August 1942, four vessels, Iowa, New Jersey, Missouri, and Wisconsin, were completed; two more, Illinois and Kentucky, were laid down but canceled in 1945 and 1958, respectively, before completion, and both hulls were scrapped in 1958–1959.
An electronic countermeasure (ECM) is an electrical or electronic device designed to trick or deceive radar, sonar, or other detection systems, like infrared (IR) or lasers. It may be used both offensively and defensively to deny targeting information to an enemy. The system may make many separate targets appear to the enemy, or make the real target appear to disappear or move about randomly. It is used effectively to protect aircraft from guided missiles. Most air forces use ECM to protect their aircraft from attack. It has also been deployed by military ships and recently on some advanced tanks to fool laser/IR guided missiles. It is frequently coupled with stealth advances so that the ECM systems have an easier job. Offensive ECM often takes the form of jamming. Self-protecting (defensive) ECM includes using blip enhancement and jamming of missile terminal homers.
The history of radar started with experiments by Heinrich Hertz in the late 19th century that showed that radio waves were reflected by metallic objects. This possibility was suggested in James Clerk Maxwell's seminal work on electromagnetism. However, it was not until the early 20th century that systems able to use these principles were becoming widely available, and it was German inventor Christian Hülsmeyer who first used them to build a simple ship detection device intended to help avoid collisions in fog. True radar which provided directional and ranging information, such as the British Chain Home early warning system, was developed over the next two decades.
The AN/SPN-46(V)1 is a Precision Approach and Landing System, manufactured in the United States, by Textron Systems, which is used on aircraft carriers of the United States Navy. The radar uses two dual-band radar antennas, which also function as transmitters, to guide planes or helicopters to the ship.
The AN/SLQ-32 is a shipboard electronic warfare suite built by the Raytheon Company of Goleta, California and The Hughes Aircraft Company. It is currently the primary electronic warfare system in use by U.S. Navy ships. Its operators commonly refer to it as the "Slick-32".
The U.S. Navy Electronics Laboratory (NEL) was created in 1945, with consolidation of the naval radio station, radar operators training school, and radio security activity of the Navy Radio and Sound Lab (NRSL) and its wartime partner, the University of California Division of War Research. NEL’s charter was “to effectuate the solution of any problem in the field of electronics, in connection with the design, procurement, testing, installation and maintenance of electronic equipment for the U.S. Navy.” Its radio communications and sonar work was augmented with basic research in the propagation of electromagnetic energy in the atmosphere and of sound in the ocean.
The CXAM radar system was the first production radar system deployed on United States Navy ships, operating in the mid-high VHF frequency band of 200 MHz. It followed several earlier prototype systems, such as the NRL radar installed in April 1937 on the destroyer Leary; its successor, the XAF, installed in December 1938 on the battleship New York; and the first RCA-designed system, the CXZ, installed in December 1938 or January 1939 on the battleship Texas. Based on testing in January 1939, where the XAF was more reliable, the US Navy ordered RCA to build six XAF-based units for deployment and then shortly thereafter ordered 14 more.
Albert Hoyt Taylor was an American electrical engineer who made important early contributions to the development of radar.
The AN/SPS-48 is a US naval electronically scanned array, air search three-dimensional radar system manufactured by ITT Exelis and deployed in the 1960s as the primary air search sensor for anti-aircraft warships. The deployment of the AN/SPY-1 and the end of the Cold War led to the decommissioning of many such ships, and many of these vessel's AN/SPS-48 sets were reused on aircraft carriers and amphibious ships where it is used to direct targets for air defense systems such as the Sea Sparrow and RIM-116 SAM missiles. Existing sets are being modernized under the ROAR program to AN/SPS-48G standard for better reliability and usability.
Robert Morris Page was an American physicist who was a leading figure in the development of radar technology. Later, Page served as the director of research for the U.S. Naval Research Laboratory.
The AN/SPS-43 was a long-range air-search United States Navy radar system introduced in March 1961 that had a range of 500+ km. This radar could provide bearing and distance information, but no altitude information. The small-ship antenna (AN/SPS-29) looked like a bedspring. Larger ships used the 12.8 m wide AN/SPS-37 antenna - about twice as wide and half the height of the SPS-29 antenna - and designed with a much narrower beam. Targets were much more accurately displayed when using the -37 antenna. The -43 operated at VHF frequency - somewhat unusual for any radar - mostly in the bandwidth of television channel 13. The main difference to the SPS-37 was the greatly improved ECCM performance, as the AN/SPS-43 could jump between 20 different frequencies to frustrate jamming attempts. A sea-skimming missile could be detected at a range distance of 30 km, a large high-flying aircraft at 500 km.
Leo C. Young was an American radio engineer who had many accomplishments during a long career at the U.S. Naval Research Laboratory. Although self-educated, he was a member of a small, creative team which some attributed to the developing the world's first true radar system.
Radar in World War II greatly influenced many important aspects of the conflict. This revolutionary new technology of radio-based detection and tracking was used by both the Allies and Axis powers in World War II, which had evolved independently in a number of nations during the mid 1930s. At the outbreak of war in September 1939, both the United Kingdom and Germany had functioning radar systems. In the UK, it was called RDF, Range and Direction Finding, while in Germany the name Funkmeß (radio-measuring) was used, with apparatuses called Funkmessgerät . By the time of the Battle of Britain in mid-1940, the Royal Air Force (RAF) had fully integrated RDF as part of the national air defence.
AN/SPS-6 is a two-dimensional radar manufactured by Bendix and Westinghouse Electric. It was used by the US Navy as a first-generation air-search radar after World War II, and was widely exported to allies. In addition, the improved AN/SPS-12 is the derivative types developed in other countries.
AN/SPS-29 is a two-dimensional radar that was manufactured by General Electric. It was used by the US Navy as an early warning radar after World War II, and was equipped aboard naval ships during the Cold War. Variants include AN/SPS-29A, AN/SPS-29B, AN/SPS-29C, AN/SPS-29D and AN/SPS-29E. After modernization, it was redesignated as AN/SPS-37.
SC was an American-made air and surface-search radar used during World War II by the United States Navy. Variations include SC-1, SC-2 and SC-3.
SK was an American-made air-search radar used during World War II by the United States Navy. Models included SK-1, SK-2 and SK-3.
SM was an American made fighter-direction radar used for the ship ground-controlled interception (GCI) during World War II by the United States Navy. Variation included the SM-1.
The AN/SPN-35 is a computerized automatic landing system installed on the Tarawa-class amphibious assault ship and other LHA/LHD-class warships to give control for aircraft during the final approach and landing.
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