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

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Description
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.
Date
Source Original version at Flickr: NASA on The Commons
This file was derived from: Horn Antenna-in Holmdel, New Jersey.jpeg
Author NASA, restored by Bammesk
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Object location40° 23′ 29″ N, 74° 11′ 07″ W Kartographer map based on OpenStreetMap.View this and other nearby images on: OpenStreetMapinfo

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This image or video was catalogued by NASA Headquarters of the United States National Aeronautics and Space Administration (NASA) under Photo ID: GPN-2003-00013 and Alternate ID: 62-Tels-20.

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Public domain This file is in the public domain in the United States because it was solely created by NASA. NASA copyright policy states that "NASA material is not protected by copyright unless noted". (See Template:PD-USGov, NASA copyright policy page or JPL Image Use Policy.)
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June 1962

40°23'29.000"N, 74°11'7.001"W

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Date/TimeThumbnailDimensionsUserComment
current01:24, 1 May 2020Thumbnail for version as of 01:24, 1 May 20202,793 × 2,197 (1.2 MB)Bammeskremoved halo along the bottom edge of the antenna
03:10, 30 April 2020Thumbnail for version as of 03:10, 30 April 20202,793 × 2,197 (1.57 MB)Bammeskreduced the fading adjustment around the periphery (truer to original)
01:50, 28 April 2020Thumbnail for version as of 01:50, 28 April 20202,793 × 2,197 (1.24 MB)Bammeskmore restoration (removed fading around the periphery)
19:03, 26 April 2020Thumbnail for version as of 19:03, 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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