AN/FPS-35
Cold War–era US early warning radar
The AN/FPS-35 was a long range early warning radar used within the SAGE network and its successors. It was one of the largest air defense radars ever produced, with an antenna 126 feet (38 m) across supported on one of the largest rolling-element bearings in the world.
The FPS-35 was one of a suite radars developed under a 1955 Rome Air Development Center project to introduce designs that were more resistant to jamming through the use of frequency diversity. The -35 shifted frequency between 420 to 450 MHz (0.71 to 0.67 m), while the similar AN/FPS-24 operated between 214 and 236 MHz (1.40 and 1.27 m) and the AN/FPS-28 between 510 and 690 MHz (0.59 and 0.43 m). These radars also incorporated moving target indication (MTI) in order to deal with significant problems that earlier designs had with radar clutter, which the SAGE computers were not able to process.
The prototype was built at Thomasville Air Force Station and declared operational in December 1960. The design proved to have many problems and only four were fully operational by 1962. A total of twelve were eventually installed. The unit at Montauk AFS produced strong interference with UHF television signals and was turned off in 1961 to be recalibrated, which had to happen several more times during its lifetime. Weighing more than 70 short tons (140,000 lb; 64,000 kg), the size of the antennas caused serious maintenance problems, and in 1966 the unit at Fortuna AFS collapsed onto the underlying building.
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Chronology, provenance and viewpoint should be read together before a broad social or political interpretation is accepted. The source revision retrieved here is dated Aug 31, 2026. The linked authority identifier is Q1698421. Authority coordinates are 41.062, -71.875. 1 of 2 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1955, 1960, 1962 and 1961.
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This entry incorporates text from “AN/FPS-35” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.