Mullard Radio Astronomy Observatory (MRAO) is home to a number of large aperture synthesis

Aperture synthesis

Aperture synthesis or synthesis imaging is a type of interferometry that mixes signals from a collection of telescopes to produce images having the same angular resolution as an instrument the size of the entire collection...

 radio telescope

Radio telescope

A radio telescope is a form of directional radio antenna used in radio astronomy. The same types of antennas are also used in tracking and collecting data from satellites and space probes...

s, including the One-Mile Telescope

One-Mile Telescope

The One-Mile Telescope at the Mullard Radio Astronomy Observatory is an array of radio telescopes designed to perform aperture synthesis interferometry.- History :The One Mile Telescope was completed by the Radio Astronomy Group of Cambridge...

, 5-km Ryle Telescope

Ryle Telescope

The Ryle Telescope was a linear east-west radio telescope array at the Mullard Radio Astronomy Observatory. In 2004 three of the telescopes were moved to create a compact two-dimensional array of telescopes at the east end of the interferometer. The remaining five antennas were switched off on 19...

, and the Arcminute Microkelvin Imager

Arcminute Microkelvin Imager

The Arcminute Microkelvin Imager consists of a pair of interferometric radio telescopes - the Small and Large Arrays - located at the Mullard Radio Astronomy Observatory near Cambridge. AMI was designed, built and is operated by the Cavendish Astrophysics Group...

. Radio interferometry started in the mid-1940s on the outskirts of Cambridge, but with funding from the Science Research Council and a donation of £100,000 from Mullard

Mullard

Mullard Limited was a British manufacturer of electronic components. The Mullard Radio Valve Co. Ltd. of Southfields, London, was founded in 1920 by Captain Stanley R. Mullard, who had previously designed valves for the Admiralty before becoming managing director of the Z Electric Lamp Co. The...

 Limited, construction of the Mullard Radio Astronomy Observatory commenced at Lord's Bridge

Lord's Bridge railway station

Lord's Bridge was a railway station on the Varsity Line which ran between Oxford and Cambridge. Situated in the north of the parish of Harlton on the western outskirts of Cambridge, it was the penultimate station before the line's eastern terminus at Cambridge. The station opened in 1862 and closed...

, a few kilometres to the west of Cambridge. The observatory was founded under Martin Ryle

Martin Ryle

Sir Martin Ryle was an English radio astronomer who developed revolutionary radio telescope systems and used them for accurate location and imaging of weak radio sources...

 of the Radio-Astronomy Group

Cavendish Astrophysics Group

The Cavendish Astrophysics Group is based at the Cavendish Laboratory at the University of Cambridge. The group operates all of the telescopes at the Mullard Radio Astronomy Observatory except for the 32m MERLIN telescope, which is operated by Jodrell Bank.The group is the second largest of three...

 of the Cavendish Laboratory

Cavendish Laboratory

The Cavendish Laboratory is the Department of Physics at the University of Cambridge, and is part of the university's School of Physical Sciences. It was opened in 1874 as a teaching laboratory....

, University of Cambridge

University of Cambridge

The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...

 and was opened by Sir Edward Victor Appleton

Edward Victor Appleton

Sir Edward Victor Appleton, GBE, KCB, FRS was an English physicist.-Biography:Appleton was born in Bradford, West Yorkshire and educated at Hanson Grammar School. At the age of 18 he won a scholarship to St John's College, Cambridge...

 on 25 July 1957. This group is now known as the Cavendish Astrophysics Group

Cavendish Astrophysics Group

The Cavendish Astrophysics Group is based at the Cavendish Laboratory at the University of Cambridge. The group operates all of the telescopes at the Mullard Radio Astronomy Observatory except for the 32m MERLIN telescope, which is operated by Jodrell Bank.The group is the second largest of three...

.

The site is located at Lord's Bridge

Lord's Bridge railway station

Lord's Bridge was a railway station on the Varsity Line which ran between Oxford and Cambridge. Situated in the north of the parish of Harlton on the western outskirts of Cambridge, it was the penultimate station before the line's eastern terminus at Cambridge. The station opened in 1862 and closed...

, Cambridgeshire

Cambridgeshire

Cambridgeshire is a county in England, bordering Lincolnshire to the north, Norfolk to the northeast, Suffolk to the east, Essex and Hertfordshire to the south, and Bedfordshire and Northamptonshire to the west...

 on a former ordnance storage facility, next to the now-abandoned Cambridge-Bedford railway line

Varsity Line

The Varsity Line is an informal name for the railway route that formerly linked the English university cities of Oxford and Cambridge, operated successively by the London and North Western Railway, the London, Midland and Scottish Railway, and British Railways...

. A portion of the track bed of the old line, running nearly East-West for several miles, was used to form the main part of the "5km"

Ryle Telescope

The Ryle Telescope was a linear east-west radio telescope array at the Mullard Radio Astronomy Observatory. In 2004 three of the telescopes were moved to create a compact two-dimensional array of telescopes at the east end of the interferometer. The remaining five antennas were switched off on 19...

 radio-telescope and the Cambridge Low Frequency Synthesis Telescope

Cambridge Low Frequency Synthesis Telescope

The Cambridge Low-Frequency Synthesis Telescope is an east-west aperture synthesis radio telescope currently operating at 151 MHz. It consists of 60 tracking yagis on a 4.6 km baseline, giving 776 simultaneous baselines. These provide a resolution of 70×70 cosec arcsec2, with a sensitivity of...

.

Telescopes

Telescope	Year built	Status
Arcminute Microkelvin Imager Arcminute Microkelvin Imager The Arcminute Microkelvin Imager consists of a pair of interferometric radio telescopes - the Small and Large Arrays - located at the Mullard Radio Astronomy Observatory near Cambridge. AMI was designed, built and is operated by the Cavendish Astrophysics Group...  Large Array	2007	In commissioning phase
Arcminute Microkelvin Imager Arcminute Microkelvin Imager The Arcminute Microkelvin Imager consists of a pair of interferometric radio telescopes - the Small and Large Arrays - located at the Mullard Radio Astronomy Observatory near Cambridge. AMI was designed, built and is operated by the Cavendish Astrophysics Group...  Small Array	2004	Active
Very Small Array Very Small Array The Very Small Array is a 14-element interferometric radio telescope operating between 26 and 36 GHz that is used to study the cosmic microwave background radiation. It is a collaboration between the University of Cambridge, University of Manchester and the Instituto de Astrofisica de Canarias...  (moved to Tenerife Tenerife Tenerife is the largest and most populous island of the seven Canary Islands, it is also the most populated island of Spain, with a land area of 2,034.38 km² and 906,854 inhabitants, 43% of the total population of the Canary Islands. About five million tourists visit Tenerife each year, the...  in 1999)	1998	Active
Cosmic Anisotropy Telescope Cosmic Anisotropy Telescope The Cosmic Anisotropy Telescope CAT was a three-element interferometer for cosmic microwave background radiation observations at 13 to 17 GHz, based at the Mullard Radio Astronomy Observatory. In 1995, it was the first instrument to measure small-scale structure in the cosmic microwave background...  made first high-resolution maps of Cosmic Microwave Background fluctuations	1995	Decommissioned
Cambridge Optical Aperture Synthesis Telescope (COAST) Cambridge Optical Aperture Synthesis Telescope COAST, the Cambridge Optical Aperture Synthesis Telescope, is a multi-element optical astronomical interferometer with baselines of up to 100 metres, which uses aperture synthesis to observe stars with angular resolution as high as one thousandth of one arcsecond COAST, the Cambridge Optical...  first aperture synthesis Aperture synthesis Aperture synthesis or synthesis imaging is a type of interferometry that mixes signals from a collection of telescopes to produce images having the same angular resolution as an instrument the size of the entire collection...  at optical wavelengths	1993	Operated on clear nights
One receiver from the MERLIN MERLIN The Multi-Element Radio Linked Interferometer Network is an interferometer array of radio telescopes spread across England. The array is run from Jodrell Bank Observatory in Cheshire by the University of Manchester on behalf of STFC as a National Facility.The array consists of up to seven radio...  array	1990	Active
Cambridge Low Frequency Synthesis Telescope Cambridge Low Frequency Synthesis Telescope The Cambridge Low-Frequency Synthesis Telescope is an east-west aperture synthesis radio telescope currently operating at 151 MHz. It consists of 60 tracking yagis on a 4.6 km baseline, giving 776 simultaneous baselines. These provide a resolution of 70×70 cosec arcsec2, with a sensitivity of...  (CLFST)	1980	Decommissioned
Ryle Telescope Ryle Telescope The Ryle Telescope was a linear east-west radio telescope array at the Mullard Radio Astronomy Observatory. In 2004 three of the telescopes were moved to create a compact two-dimensional array of telescopes at the east end of the interferometer. The remaining five antennas were switched off on 19...  (formerly 5-Kilometre Telescope)	1971	Decommissioned (2006)
Half-Mile Telescope Half-Mile Telescope The Half-Mile Telescope was constructed in 1968 at the Mullard Radio Astronomy Observatory with two more aerials being added in 1972, using donated dishes . Two of the dishes are fixed, while two are moveable and share the One-Mile's rail track; to obtain information from the maximum number of...	1968	Decommissioned
Interplanetary Scintillation Array Interplanetary Scintillation Array The Interplanetary Scintillation Array was built at the Mullard Radio Astronomy Observatory in 1967 and originally covered four acres . It was extended in 1978 to nine, and re-furbished in 1989. It operates at 81.5 MHz , and is made up of 4096 dipoles in a phased array. 14 beams can map the...  discovered first pulsar Pulsar A pulsar is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. The radiation can only be observed when the beam of emission is pointing towards the Earth. This is called the lighthouse effect and gives rise to the pulsed nature that gives pulsars their name...	1967	Decommissioned
One-Mile Telescope One-Mile Telescope The One-Mile Telescope at the Mullard Radio Astronomy Observatory is an array of radio telescopes designed to perform aperture synthesis interferometry.- History :The One Mile Telescope was completed by the Radio Astronomy Group of Cambridge...	1964	Decommissioned
4C Array 4C Array The 4C Array is a cylindrical paraboloid radio telescope at the Mullard Radio Astronomy Observatory. It is similar in design to the Molonglo Observatory Synthesis Telescope. It is 450 m long, 20 m wide, with a second, moveable element... , first telescope at the Cambridge's new observatory, used to make the 4C catalogue Fourth Cambridge Survey The Fourth Cambridge Survey is an astronomical catalogue of celestial radio sources as measured at 178 MHz using the 4C Array. It was published in two parts, in 1965 and 1967 , by the Radio Astronomy Group of the University of Cambridge...	1958	Decommissioned

Sources

• The Mullard Radio Astronomy Observatory webpage
• Image from Google maps showing the One-Mile
  One-Mile Telescope
  The One-Mile Telescope at the Mullard Radio Astronomy Observatory is an array of radio telescopes designed to perform aperture synthesis interferometry.- History :The One Mile Telescope was completed by the Radio Astronomy Group of Cambridge...
  
  , Half Mile
  Half-Mile Telescope
  The Half-Mile Telescope was constructed in 1968 at the Mullard Radio Astronomy Observatory with two more aerials being added in 1972, using donated dishes . Two of the dishes are fixed, while two are moveable and share the One-Mile's rail track; to obtain information from the maximum number of...
  
  , 4C Array
  4C Array
  The 4C Array is a cylindrical paraboloid radio telescope at the Mullard Radio Astronomy Observatory. It is similar in design to the Molonglo Observatory Synthesis Telescope. It is 450 m long, 20 m wide, with a second, moveable element...
  
  , MERLIN
  MERLIN
  The Multi-Element Radio Linked Interferometer Network is an interferometer array of radio telescopes spread across England. The array is run from Jodrell Bank Observatory in Cheshire by the University of Manchester on behalf of STFC as a National Facility.The array consists of up to seven radio...
  
  , COAST
  Cambridge Optical Aperture Synthesis Telescope
  COAST, the Cambridge Optical Aperture Synthesis Telescope, is a multi-element optical astronomical interferometer with baselines of up to 100 metres, which uses aperture synthesis to observe stars with angular resolution as high as one thousandth of one arcsecond COAST, the Cambridge Optical...
  
  , CAT
  Cosmic Anisotropy Telescope
  The Cosmic Anisotropy Telescope CAT was a three-element interferometer for cosmic microwave background radiation observations at 13 to 17 GHz, based at the Mullard Radio Astronomy Observatory. In 1995, it was the first instrument to measure small-scale structure in the cosmic microwave background...
  
   and Ryle
  Ryle Telescope
  The Ryle Telescope was a linear east-west radio telescope array at the Mullard Radio Astronomy Observatory. In 2004 three of the telescopes were moved to create a compact two-dimensional array of telescopes at the east end of the interferometer. The remaining five antennas were switched off on 19...
  
  telescopes.
• Subterranea Britannica entry for Lord's Bridge Forward Filling Depot (also Air Ammunition Park)
• Subterranea Britannica entry for Lord's Bridge Station