The Long Michelson Interferometer was a radio telescope

interferometer Interferometry is a technique which uses the '' interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber o ...

built by

Martin Ryle Sir Martin Ryle (27 September 1918 – 14 October 1984) was an English radio astronomer who developed revolutionary radio telescope systems (see e.g. aperture synthesis) and used them for accurate location and imaging of weak radio sour ...

and co-workers in the late 1940s beside a rifle range to the west of

Cambridge Cambridge ( ) is a university city and the county town in Cambridgeshire, England. It is located on the River Cam approximately north of London. As of the 2021 United Kingdom census, the population of Cambridge was 145,700. Cambridge beca ...

, England. The interferometer consisted of 2 fixed elements 440m apart to survey the sky using Earth rotation. It produced th
Preliminary survey of the radio stars in the Northern Hemisphere
at 45 MHz - 214 MHz. The telescope was operated by the Radio Astronomy Group of

Cambridge University , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

and

Antony Hewish Antony Hewish (11 May 1924 – 13 September 2021) was a British radio astronomer who won the Nobel Prize for Physics in 1974 (together with fellow radio-astronomer Martin Ryle) for his role in the discovery of pulsars. He was also awarded th ...

received the

Nobel Prize for Physics ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...

in 1974 for this and later work in radio interferometry.

References

A preliminary survey of the radio stars in the Northern Hemisphere
Ryle, M.; Smith, F. G.; Elsmore, B., (1950),

Monthly Notices of the Royal Astronomical Society ''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics. It has been in continuous existence since 1827 and publishes letters and papers reporting origina ...

, Vol. 110, p. 508 Cavendish Laboratory Radio telescopes Interferometric telescopes 1940s establishments in England {{observatory-stub