They also called him one of the leading forces behind the radio telescope LOFAR. A typical size of the single antenna of a radio telescope is 25 meters. Ceduna has a radio telescope that is integrated into the CSIRO radio telescope network. Secret objects, like the Irbene radio telescope were built here. Pulsars were discovered in 1967 using a radio telescope. Another potential candidate for a radio telescope is the Saha crater. It was first used as an interferometer with the Arecibo radio telescope in 1969. This included resetting the location from a radio telescope to a signals intelligence ground station. The radio telescope has a diameter of . Early radio telescope interferometers used a single baseline for measurement. This is similar in operation to the Arecibo Radio Telescope. The basic design of FAST is similar to the Arecibo Observatory radio telescope. The first purpose built radio telescope went into operation in 1937. It operates the radio telescope in Effelsberg. In 1982, NPO Lavochkin had completed technical blueprints for RadioAstron, a space-based radio telescope.