Slika:Horn Antenna-in Holmdel, New Jersey - restoration1.jpg

Izvorna datoteka(2.793 × 2.197 točk, velikost datoteke: 1,2 MB, MIME-vrsta: image/jpeg)


To je slika kraja ali stavbe z vnosom v Državnem registru zgodovinskih krajev Združenih držav Amerike. Sklicna številka je 89002457..

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 To je izbrana slika v Wikipediji v jeziku: angleščina (Featured pictures) in je ovrednotena kot ena njenih najboljših slik.

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Povzetek

Opis
English: The 15 meter Holmdel horn antenna at Bell Telephone Laboratories in Holmdel, New Jersey was built in 1959 for pioneering work in communication satellites for the NASA ECHO I. The antenna was 50 feet in length and the entire structure weighed about 18 tons. It was composed of aluminum with a steel base. It was used to detect radio waves that bounced off Project ECHO balloon satellites. The horn was later modified to work with the Telstar Communication Satellite frequencies as a receiver for broadcast signals from the satellite. In 1964, radio astronomers Robert Wilson and Arno Penzias discovered the cosmic microwave background radiation with it, for which they were awarded the 1978 Nobel prize in physics. In 1990 the horn was dedicated to the National Park Service as a National Historic Landmark.
This type of antenna is called a Hogg or horn-reflector antenna, invented by Albert Beck and Harald Friis in 1941 and further developed by D. C. Hogg at Bell Labs in 1961. It consists of a flaring metal horn with a reflector mounted in the mouth at a 45° angle, so the antenna receives radio waves at a 90° angle to the horn axis. The reflector is a segment of a parabolic reflector, so the antenna is equivalent to a parabolic antenna fed off-axis. This type of antenna has characteristics that make it a good radio telescope: it has very broad bandwidth, the aperture efficiency can be calculated accurately, and the horn shields the antenna from electrical noise coming from angles outside the beam axis, so it picks up little thermal ground noise.
Datum
Vir Original version at Flickr: NASA on The Commons
Ta datoteka je izpeljana iz: Horn Antenna-in Holmdel, New Jersey.jpeg
Avtor NASA, restored by Bammesk
Druge različice
Lokacija objekta40° 23′ 29″ S, 74° 11′ 07″ Z Kartographer map based on OpenStreetMap.Ta in druge slike po lokaciji: OpenStreetMapinfo

Licenca

To sliko ali ta video je katalogiziral NASA Headquarters Nacionalne uprave za aeronavtiko in vesolje (NASA) Združenih držav Amerike pod oznako fotografije: GPN-2003-00013 in druga oznaka: 62-Tels-20.

Ta predloga ne označuje avtorskopravnega stanja dela. Ob njej mora stati tudi običajna oznaka avtorskopravnega stanja gradiva. Glejte Commons:Navedba licence.
Drugi jeziki:
Public domain Ta datoteka je v javni domeni, ker jo je izdelala izključno NASA. Avtorskopravna politika NASE pravi, da »Gradivo NASE ni zaščiteno z avtorskimi pravicami, razen če je rečeno drugače.« (glej Template:PD-USGov, stran z avtorskopravno politiko NASE ali Politiko uporabe slik JPL.)
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motiv

Holmdel Horn Antenna angleščina

junij 1962

40°23'29.000"N, 74°11'7.001"W

image/jpeg

Zgodovina datoteke

Kliknite datum in čas za ogled datoteke, ki je bila takrat naložena.

Datum in časSličicaVelikostUporabnikKomentar
trenutno03:24, 1. maj 2020Sličica za različico z datumom 03:24, 1. maj 20202.793 × 2.197 (1,2 MB)Bammeskremoved halo along the bottom edge of the antenna
05:10, 30. april 2020Sličica za različico z datumom 05:10, 30. april 20202.793 × 2.197 (1,57 MB)Bammeskreduced the fading adjustment around the periphery (truer to original)
03:50, 28. april 2020Sličica za različico z datumom 03:50, 28. april 20202.793 × 2.197 (1,24 MB)Bammeskmore restoration (removed fading around the periphery)
21:03, 26. april 2020Sličica za različico z datumom 21:03, 26. april 20202.793 × 2.197 (1,13 MB)BammeskUploaded a work by NASA from https://www.flickr.com/photos/nasacommons/16315677368/in/photolist-qRL7sd with UploadWizard

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