The Black Beacon against a distant storm cloud, Orford Ness, Suffolk, England.
The Orfordness Rotating Wireless Beacon, known simply as the Orfordness Beacon or sometimes the Black Beacon, was an early radio navigation system introduced by the United Kingdom in July 1929. It allowed the angle to the station to be measured from any aircraft or ship with a conventional radio receiver, and was accurate to about a degree. A second station operating on the same principle was set up to provide wider area coverage and allow two-bearing fixes between Orford Ness and Farnborough Airport. The system was similar to the earlier German Telefunken Kompass Sender and the later Sonne system. In navigation, the determination of a "fix" requires two measurements to be taken. Using classical triangulation techniques, this was normally the measurement of two angles, or bearings, along the line-of-sight to prominent landmarks, like a lighthouse. After taking the two measurements, lines of position are drawn radiating from the landmark along the reverse angle. They will cross at some point, and their intersection determines the location of the navigator. A report compiled for the Merchant Marine demonstrated an effective range of about 100 miles, day or night. During the day, a minimum accuracy of 2 degrees measured, and 1 degree was common. However, at night the system degraded considerably, with measurement errors as great as 20 degrees.
Size: 3735px × 5603px
Location: Orford Ness, Suffolk, England.
Photo credit: © TONY LOCKHART / Alamy / Afripics
License: Royalty Free
Model Released: No
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