A radio quiet zone is an area where

radio Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmi ...

transmissions are restricted in order to protect a radio telescope or a communications station from

radio frequency interference Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrost ...

. The Radio Regulations of the

International Telecommunication Union The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...

(ITU) define interference as being detrimental to radio astronomy if it increases measurement uncertainty by 10%. In particular, the applicable regulation is known as ITU-R Recommendation RA.769, "Protection criteria used for radio astronomical measurements". Equipment that can cause interference includes

mobile phone A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link whi ...

television transmitter A television transmitter is a transmitter that is used for terrestrial (over-the-air) television broadcasting. It is an electronic device that radiates radio waves that carry a video signal representing moving images, along with a synchronized ...

s, and

CB radio Citizens band radio (also known as CB radio), used in many countries, is a land mobile radio system, a system allowing short-distance person-to-many persons bidirectional voice communication among individuals, using two way radios operating on ...

s, as well as other electrical equipment. Quiet zones are located in areas that are sparsely populated, and may be enforced by government legislation. A radio quiet zone is often divided into two zones: an exclusion zone where all radio emissions are prohibited, and a larger coordination zone of up to 100 km² where the power levels of radio transmissions are suitably limited so as not to interfere with the radio telescope. Formal radio quiet zones exist around many observatories, including the

Murchison Radio-astronomy Observatory The Murchison Radio-astronomy Observatory (MRO) was established by CSIRO (Commonwealth Scientific and Industrial Research Organisation) in 2009. It lies in a designated radio quiet zone located near Boolardy Station in the Murchison Shire of ...

in Australia, the National Radio Astronomy Observatory and the

Sugar Grove Station Sugar Grove Station is a National Security Agency (NSA) communications site located near Sugar Grove in Pendleton County, West Virginia. According to a 2005 article in ''The New York Times'', the site intercepts all international communications e ...

in West Virginia, United States (the

United States National Radio Quiet Zone The National Radio Quiet Zone (NRQZ) is a large area of land in the United States designated as a radio quiet zone, in which radio transmissions are restricted by law to facilitate scientific research and the gathering of military intelligence ...

), the Itapetinga Radio Observatory in Brazil, and MeerKAT in South Africa as examples. The ITU has recommended designating two locations in

outer space Outer space, commonly shortened to space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty—it is a near-perfect vacuum containing a low density of particles, pred ...

as radio quiet zones: the shielded zone on the Moon's far side, and the Sun-Earth Lagrangian point L₂.

References

{{Reflist, 40em, refs= {{cite web, publisher=Australian Government, Department of Innovation, Industry, Science and, title=Radio quiet in the Mid West, url=http://www.ska.gov.au/Observatory/Pages/RadioQuiet.aspx, website=www.ska.gov.au, accessdate=13 April 2017, language=en {{cite web, title=National Radio Quiet Zone — Science Website, url=https://science.nrao.edu/facilities/gbt/interference-protection/nrqz/, website=science.nrao.edu, accessdate=13 April 2017, language=en {{cite journal, title=The importance of Radio Quiet Zone (RQZ) for radio astronomy, journal=AIP Conference Proceedings, date=8 May 2013, volume=1528, issue=1, pages=32–37, doi=10.1063/1.4803564, issn=0094-243X, last1=Umar, first1=Roslan, last2=Abidin, first2=Zamri Zainal, last3=Ibrahim, first3=Zainol Abidin, bibcode=2013AIPC.1528...32U {{cite web, title=Radiobservatório do Itapetinga - ROI/INPE, url=http://www.cea.inpe.br/roi/zonasilencio.php, website=www.cea.inpe.br, accessdate=9 October 2017 {{citation , contribution=Radio quiet, please! - protecting radio astronomy from interference , last1=van Driel , first1=W. , postscript=. , title=The Role of Astronomy in Society and Culture, Proceedings of the International Astronomical Union, IAU Symposium, Volume 260, p. 457-464 , publisher=International Astronomical Union , date=June 2011 , volume=260 , page=457 , doi=10.1017/S1743921311002675 , bibcode=2011IAUS..260..457V , arxiv=0906.2268, s2cid=118632363 {{citation , postscript=. , contribution=Radio Quiet Zones , display-authors=1 , last1=Cohen , first1=J. , last2=Delgado , first2=G. , last3=Hardy , first3=E. , last4=Hasegawa , first4=T. , last5=Nyman , first5=L.-A. , title=Light Pollution: The Global View , editor1-first=H. E. , editor1-last=Schwarz , series=Astrophysics and Space Science Library , publisher=Kluwer Academic Publishers, Dordrecht , volume=284 , page=225 , date=April 2003 , doi=10.1007/978-94-017-0125-9_21 , bibcode=2003ASSL..284..225C

External links

Radio quiet zones around observatories
CRAF Electromagnetic compatibility Radio astronomy

See also

References

External links