Radio quiet zones around observatories

Usually, a radio quiet zone has been established around a radio astronomy station. Within such an area motorized traffic is severely restricted or forbidden, and there may be several severe restrictions on the use of electronic equipment and on the existences of e.g. factories, buildings and construction works within that area: i.e. radio quiet means really quiet.

In addition, it is common practice that for specific electronic equipment, such as for mobile earth stations, administrations determine separation distances around radio astronomy stations. These separation distances are usually larger than the extent of the generic radio quiet zone. These specific distances depend on the transmission characteristics of this equipment and on the frequency on which it operates.

In the different European countries the situation for the radio quiet zones is as follows:

Country Radio Astronomy Observatory Separation distance from radio astronomy station Regulatory Process
Belgium Humain No well-defined radio quiet zone. A general coordination area with a radius of ~2-3 km exists around the radio astronomy station The coordination area has been established by the local authorities
Czech Republic Ondrejov 0.5 – 1.0 km This zone and a coordination area of ~15 km diameter aound the radio astronomy station have been established by the local authorities
Finland Metsähovi about 1 km The radio quiet zone has been established in consultation with the Finnish national regulatory authority
France Bordeaux Each radio astronomy station in France is registered as radio quiet zone. However, no real well-defined radio quiet zone or coordination area All applications for licenses pass through the Commission des Sites et Servitudes in which the radio astronomy service has a representative and through the Commission d’Assignation des Fréquences in which the radio astronomy service is also represented. This representative can object to any application and after the process of evaluation of the application, a coordination takes place. If no agreement is possible, the Agence National des Fréquences will decide the case. The procedure to create a quiet zone is very complicated.
Nançay Each radio astronomy station in France is registered as radio quiet zone. However, no real well-defined radio quiet zone or coordination area. It is not allowed to install a transmitter within a few km from each of the radio astronomy telescopes All applications for licenses pass through the Commission des Sites et Servitudes in which the radio astronomy service has a representative and through the Commission d’Assignation des Fréquences in which the radio astronomy service is also represented. This representative can object to any application and after the process of evaluation of the application, a coordination takes place. If no agreement is possible, the Agence National des Fréquences will decide the case. The procedure to create a quiet zone is very complicated.
Plateau de Bure 3 km radius. All applications for licenses pass through the Commission des Sites et Servitudes in which the radio astronomy service has a representative and through the Commission d’Assignation des Fréquences in which the radio astronomy service is also represented. This representative can object to any application and after the process of evaluation of the application, a coordination takes place. If no agreement is possible, the Agence National des Fréquences will decide the case. The procedure to create a quiet zone is very complicated. In practice all issues are settled by coordination with the regulatory authority.
Germany Effelsberg No well-defined radio quiet zone or coordination area occasional coordination accomplished with local administration
Tremsdorf No well-defined radio quiet zone or coordination area occasional coordination accomplished with local administration
Wettzell No well-defined radio quiet zone or coordination area occasional coordination accomplished with local administration
Hungary Penc about 2 km radius Any new construction within the radio quiet zone has to be authorized by the local administration with the consent of the Institute for Geodesy, Cartography and Remote Sensing
Italy Medicina 2 km radius The zone has been established by the Medicina Municipality
Noto no regulatory quiet zone since station is surrounded by hills
Sardinia station under construction: no quiet zone defined yet
Latvia Riga No well-defined radio quiet zone or coordination area Issue under discussion with Latvian administration
the Netherlands Dwingeloo 1-2 km radius The radio quiet zone has been established by the regional administration in consultation with the Dutch Radiocommunication Agency
Westerbork about 2 km The radio quiet zone has been established by the regional administration in consultation with the Dutch Radiocommunication Agency
Poland Kraków No well-defined radio quiet zone or coordination area
Torun As yet no radio quiet zone. However, as a function of distance (up to 50 km) construction of buildings and installations which may possibly cause harmful interference is regulated Arrangments for the regulation zone are established by the local authorities
Portugal Espiunca No well-defined radio quiet zone or coordination area Portuguese law foresees the installation of radio quite zones but implementation is currently subject to discussions between the Portuguese national administration and the Univerity of Porto
Russia Badary No well-defined radio quiet zone or coordination area In specific cases coordination with radio astronomy station by Russian administration
Dmitrov No well-defined radio quiet zone or coordination area In specific cases coordination with radio astronomy station by Russian administration
Kalyazin No well-defined radio quiet zone or coordination area In specific cases coordination with radio astronomy station by Russian administration
Medveziy Ozera No well-defined radio quiet zone or coordination area In specific cases coordination with radio astronomy station by Russian administration
Puschino No well-defined radio quiet zone or coordination area In specific cases coordination with radio astronomy station by Russian administration
Svetloe No well-defined radio quiet zone or coordination area In specific cases coordination with radio astronomy station by Russian administration
Zelenchukskaya No well-defined radio quiet zone or coordination area In specific cases coordination with radio astronomy station by Russian administration
Zimenky No well-defined radio quiet zone or coordination area In specific cases coordination with radio astronomy station by Russian administration
Spain Pico Veleta A section in the international treaty setting up the observatory engages the Spanish administration to protect the quality of the site.
Sweden Onsala complicated function of azimuth. The radio quiet zone has been defined by national law approved by the Swedish Parliament
Switzerland Bleien (Zürich) No well-defined radio quiet zone or coordination area Issue still under discussion with Regulatory Authority
Turkey
United Kingdom Cambridge 0.5-1 km Arrangement established by Radiocommunications Agency
Jodrell Bank 0.5-1 km Arrangement between University of Manchester and local administrations
sites of the Multi-Element Radio-Linked Interferometer Network, MERLIN 0.1 km Regulatory protection through the Radiocommunications Agency

Note:

The separation distance depends on the characteristics of the radio astronomy station (whether it is a single dish instrument, an interferometer or participating in Very Long Baseline Interferometry), the frequencies used and the research priorities (spectral line or continuum emission).