The radio astronomy observatory of the University of Cambridge, founded in 1957 at Lord’s Bridge near Cambridge, England. The technique of aperture synthesis was developed at MRAO. Many radio sources are referred to by their designations in the third, fourth, fifth, etc. Cambridge sky surveys (3C, 4C, 5C, etc.). The One-Mile Telescope, which operated 1964–99, was a pioneering aperture-synthesis instrument, consisting of three 18-m dishes in an east–west line. It was succeeded in 1972 by the Ryle Telescope (originally the Five-Kilometre Telescope), which operated until 2006. The Cambridge Low Frequency Synthesis Telescope (CLFST), operated 1980–2000, was a survey instrument consisting of 60 Yagi antennas arranged along the line of the Ryle Telescope. The Interplanetary Scintillation Array of 4096 dipole antennas covering 3.6 hectares studied the scintillation of radio sources 1978–1992; an earlier version of this instrument, half the area, detected the first pulsars in 1967. The Arcminute MicroKelvin Imager (AMI) is a twin array for studying features in the cosmic microwave background. The AMI Small Array, consisting of ten 3.7-m antennae with baselines of 5–20 m, came into operation in 2005. The AMI Large Array, which started operation in 2008, consists of the eight 13-m dishes of the former Ryle Telescope rearranged to give baselines of 18–110 m. MRAO also hosts a 32-m dish of the e-MERLIN network.

http://www.mrao.cam.ac.uk/outreach/radio-telescopes/ Official observatory website.