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satellite radio
(Encyclopedia)satellite radio: see digital radio. ...radio altimeter
(Encyclopedia)radio altimeter: see altimeter.radio beacon
(Encyclopedia)radio beacon: see radio range.Radio City
(Encyclopedia)Radio City: see Rockefeller Center. ...radio compass
(Encyclopedia)radio compass: see radio range.radio frequency
(Encyclopedia)radio frequency, range of electromagnetic waves with a frequency or wavelength suitable for communication uses. Some of these waves serve as carriers of the lower-frequency audio waves; others are mod...radio range
(Encyclopedia)radio range, geographically fixed radio transmitter that radiates coded signals in all directions to enable aircraft and ships to determine their bearings. An aircraft or ship can determine its line o...CB radio
(Encyclopedia)CB radio: see radio.gamma-ray astronomy
(Encyclopedia)gamma-ray astronomy, study of astronomical objects by analysis of the most energetic electromagnetic radiation they emit. Gamma rays are shorter in wavelength and hence more energetic than X rays (see...X-ray astronomy
(Encyclopedia)X-ray astronomy, study of celestial objects by means of the X rays they emit, in the wavelength range from 0.01 to 10 nanometers. X-ray astronomy dates to 1949 with the discovery that the sun emits X ...Browse by Subject
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