sentences:  After construction adjacent to Fort Drum in June 1952, the operation moved to the Air Force Station, one of the first twenty-four Air Defense Command radar stations of the permanent network established 1950-1951 after the USAF directed construction of the sites on December 2, 1948.Watertown AFS used AN/FPS-3 and AN/FPS-5 radars for warning and ground-controlled interception.In 1958 this site was operating with AN/FPS-20 search radar and General Electric AN/FPS-6 Radar for height-finding.