Description of the radar set, tactical-technical characteristics
MIT’s Radiation Laboratory
|frequency:||2 700 … 2 900 MHz|
|pulse repetition time (PRT):||1 575 µs|
|pulse repetition frequency (PRF):||635 Hz|
|pulsewidth (τ):||2 µs|
|peak power:||750 kW|
|instrumented range:||90 NM|
|beamwidth:||β= 4.7°; ε= 1.2°|
|hits per scan:|
AN/CPS-4 height-finding radar
AN/CPS-4 “Beaver Tail” was a medium range S-Band nodding height-finding radar developed by MIT’s Radiation Laboratory used by the United States Air Force Air Defense Command. The radar was designed to be used in conjunction with the SCR-270 and SCR-271 search sets.
The CPS-4 required six operators. This S-band radar could detect targets at a distance of ninety miles. It showed these targets on an RHI-scope. The AN/CPS-4 antenna was horn fed with a reflector 20 x 5 ft shaped as an elliptical section of a paraboloid. The antenna gave a beam 1.2° wide in the vertical plane, and to pick up the targets in altitude this was raised and lowered 25 cycles per minute by nodding the antenna structure between −2° and 32°. The radars accuracy was 1000 ft in absolute altitude and 500 ft in relative altitude at 45 miles range, preferably 90 miles. This radar was often paired with the AN/FPS-3 search radar during the early 1950s at permanent network radar sites.
The first production model AN/CPS-4 came out in June 1945. The AN/CPS-4 was installed e.g. in der Keesler AFB, in US Omaha Air Force Station (AFS) and Belleville AFS, as well as in Germany on the Erbeskopf-Site. The AN/CPS-4 was also used in meteorology, to explore the structure of the “Bright Band”.
Sources and ressorces:
- Chas. R. Burrows, Stephen S. Attwood: “Radio Wave Propagation, Consolidated Summary Technical Report of the Committee on Propagation of the National Defense Research Committee”, Academic Press Inc. New York, 1949, p. 65 (online preview)
- Mark L. Morgan, Mark A. Berhow: “Rings of Supersonic Steel. Air Defenses of the United States Army 1950-1979: an Introductory History and Site Guide” Hole In The Head Press, 2002, ISBN 0615120121, p. 135, 175 (online preview)
- L Brown: “Technical and Military Imperatives. A Radar History of World War 2” CRC Press, 1999, ISBN 0750306599, p. 443 (online preview)