Sardinia Radio Telescope

Summary

Sardinia Radio Telescope
Innaugurazione SRT.JPG
Alternative namesSRT Edit this on Wikidata
Part ofCagliari Observatory Edit this on Wikidata
Location(s)San Basilio, Province of Cagliari, Sardinia, Italy
Coordinates39°29′34″N 9°14′42″E / 39.4928°N 9.245°E / 39.4928; 9.245Coordinates: 39°29′34″N 9°14′42″E / 39.4928°N 9.245°E / 39.4928; 9.245 Edit this at Wikidata
OrganizationINAF Edit this on Wikidata
Altitude600 m (2,000 ft) Edit this at Wikidata
First light8 August 2012 Edit this on Wikidata
Telescope styleradio telescope Edit this on Wikidata
Diameter64 m (210 ft 0 in) Edit this at Wikidata
Secondary diameter7.9 m (25 ft 11 in) Edit this at Wikidata
Mass3,300 t (3,300,000 kg) Edit this at Wikidata
Websitewww.srt.inaf.it Edit this at Wikidata
Sardinia Radio Telescope is located in Italy
Sardinia Radio Telescope
Location of Sardinia Radio Telescope
Related media on Wikimedia Commons

The Sardinia Radio Telescope (SRT) is 64-metre fully steerable radio telescope near San Basilio, Province of Cagliari, Sardinia, Italy. Completed in 2011, it is a collaboration between the Istituto di Radioastronomia di Bologna, the Cagliari Observatory (Cagliari) and the Arcetri Astrophysical Observatory (Florence).

Design

The telescope is in Sardinia, 35 kilometres (22 mi) north of Cagliari,[1] and is the largest[2] of a set of three telescopes operated by INAF, along with telescopes at the Medicina Radio Observatory and the Noto Radio Observatory. It operates as a stand-alone instrument and as part of global networks of telescopes. The telescope and its structure weighs around 3,300 tonnes (3,300,000 kg).[1]

The primary mirror is 64 metres (210 ft) in diameter. It has an active surface consisting of 1008 aluminum panels in 14 rows. Each panel has an area between 2.4 and 5.3 square metres. There are 1116 actuators mounted on the backing structure, which move the surface panels correct for the distortion of the mirror with elevation. A quadrupod supports a 7.9 metres (26 ft) diameter subreflector, with 49 panels in three rows, as well as primary focus instrumentation.[1]

The telescope is fully steerable. The telescope sits on a reinforced concrete base, carved into bedrock, with a continuously-welded track sitting on a 40 metres (130 ft) diameter outer ring, connected to the foundations with 260 pairs of anchor bolts, and supporting 16 wheels. In the centre is the azimuth bearing support, as well as the cable wrap and encoder system. The welded steel alidade then supports the elevation wheel, which is in turn connected to the primary mirror backing structure. A room at the base of the alidade holds the motor power supplies, antenna control system, and cryogenic compressors. Three rooms just below the primary surface contain the secondary focus receivers, as well as smaller mirrors and electronics.[1]

The telescope will ultimately have 0.3–115 GHz (1 metre to 3mm) continuous frequency coverage.[1] Initially three receivers were installed: an L band receiver in prime focus, a C-band receiver in the tertiary focus, and a 7-beam K-band receiver in the secondary focus.[3]

Collaboration, construction and commissioning

The telescope is a collaboration between the research units of the National Institute for Astrophysics: the Istituto di Radioastronomia di Bologna, the Cagliari Observatory (Cagliari) and the Arcetri Astrophysical Observatory. Construction was funded by the Italian Ministry of Education and Scientific Research, the Sardinia Regional Government, the Italian Space Agency and INAF.[3] The telescope cost around €70 million to construct.[4]

The contract to fabricate the telescope structure and mechanics started in 2003, and the construction of the foundations was completed in 2004. The initial schedule was for inauguration in late-2006;[5] construction ultimately was completed in mid-2012.[3]

The telescope was constructed by MT Mechatronics GmbH of Germany. The first light was on 8 August 2012, using the Moon and 3C218 (Alphard). The technical commissioning phase ended in 2013, and formal inauguration was on 30 September 2013,[1] with scientific commissioning between 2012 and 2015. Its first VLBI connection was in January 2014.[3]

Science

The telescope can operate in single dish mode, measuring continuum, polarisation and spectra. It is also used for very-long-baseline interferometry as part of the European VLBI Network, and with the space-based RadioAstron antenna. It is also used for space science,[1] including deep space communication by the Italian Space Agency.[2]

References

  1. ^ a b c d e f g P. Bolli; A. Orlati; L. Stringhetti; et al. (December 2015). "Sardinia Radio Telescope: General Description, Technical Commissioning and First Light". Journal of Astronomical Instrumentation. 04 (03n04): 1550008. arXiv:1603.06134. Bibcode:2015JAI.....450008B. doi:10.1142/S2251171715500087. ISSN 2251-1717. Wikidata Q58921089.
  2. ^ a b Cortes-Medellin, G. (June 2002). "The 64 m Sardinia radio telescope optics design". IEEE Antennas and Propagation Society International Symposium (IEEE Cat. No.02CH37313). 4: 136–139 vol.4. doi:10.1109/APS.2002.1016944. ISBN 0-7803-7330-8.
  3. ^ a b c d I. Prandoni; M. Murgia; A. Tarchi; et al. (December 2017). "The Sardinia Radio Telescope. From a technological project to a radio observatory". Astronomy & Astrophysics. 608: 40–40. arXiv:1703.09673. Bibcode:2017A&A...608A..40P. doi:10.1051/0004-6361/201630243. ISSN 0004-6361. Wikidata Q58914627.
  4. ^ "Inauguration of the biggest radio telescope in Europe". ResearchItaly - Inauguration of the biggest radio telescope in Europe. Retrieved 8 December 2019.
  5. ^ Grueff, Gavril; Alvito, Giovanni; Ambrosini, Roberto; Bolli, Pietro; Maccaferri, Andrea; Maccaferri, Giuseppe; Morsiani, Marco; Mureddu, Leonardo; Natale, Vincenzo; Olmi, Luca; Orfei, Alessandro; Pernechele, Claudio; Poma, Angelo; Porceddu, Ignazio; Rossi, Lucio; Zacchiroli, Gianpaolo (28 September 2004). Oschmann, Jr, Jacobus M (ed.). "Sardinia Radio Telescope: the new Italian project". Ground-based Telescopes. International Society for Optics and Photonics. 5489: 773–783. Bibcode:2004SPIE.5489..773G. doi:10.1117/12.550332.