To meet more stringent ballistic missile test requirements, several systems were designed, procured and added to the US Air Force Eastern Range's instrumentation in the 1950s and 1960s. The AZUSA continuous wave tracking system was added to the Cape in the mid-1950s and Grand Bahama in the early 1960s. The AN/FPS-16 radar system was introduced at the Cape, Grand Bahama, San Salvador, Ascension and East Grand Bahama Island between 1958 and 1961. In the early 1960s, the MISTRAM (Missile Trajectory Measurement) system was installed at Valkaria, Florida and Eleuthera island in the Bahamas to support Minuteman missile flights.