History of San Clemente Island, CA
This Lashup-Permanent radar site began operations in November 1951 with an AN/TPS-1C search radar. The LP-39 site was then replaced by Permanent site P-39. The 670th AC&W Squadron began operations in May 1952 with a single AN/FPS-3 radar. A year later, an AN/FPS-4 height-finder radar joined the site. In 1955 an AN/FPS-8 came to the island; this radar subsequently was converted to a AN/GPS-3. In 1956 an AN/FPS-6 height-finder radar replaced the AN/FPS-4. This site was deactivated in 1960, and the 670th AC&W Squadron relocated to Fort MacArthur / San Pedro Hill AFS (RP-39), a joint-use Air Force / Army / FAA radar site. San Clemente Island was handed over to the Navy. In 1972, at a new location to the south on Mount Thirst, the Navy installed an AN/FPS-20 search radar (later modified to the FPS-93A version) in an arctic tower for range safety and bombing exercises. In the late 1990's, the AN/FPS-93A was replaced by an ARSR-4 radar at the Mount Thirst location, and is now shared with the Air Force for the JSS program (the FAA maintains the radar for the Navy, but reportedly does not use the data).
References: "Searching the Skies"; misc. ADCOM documents; eyewitness accounts.
Hide