DocumentCode :
956512
Title :
Time and frequency applications
Author :
Hellwig, Helmut
Author_Institution :
US Air Force Office of Sci. Res., Bolling AFB, Washington, DC, USA
Volume :
40
Issue :
5
fYear :
1993
Firstpage :
538
Lastpage :
543
Abstract :
An overview is given of the capabilities of atomic clocks and quartz crystal oscillators in terms of available precision of time and frequency signals. The generation, comparison, and dissemination of time and frequency is then discussed. The principal focus is to survey uses of time and frequency in navigation, communication, and science. The examples given include the Global Positioning System, a satellite-based global navigation system, and general and dedicated communication networks, as well as experiments in general relativity and radioastronomy. The number of atomic clocks and crystal oscillators that are in actual use worldwide is estimated.<>
Keywords :
atomic clocks; crystal resonators; frequency measurement; measurement standards; oscillators; quartz; time measurement; Global Positioning System; SiO/sub 2/; atomic clocks; dedicated communication networks; quartz crystal oscillators; satellite-based global navigation system; Atomic clocks; Degradation; Frequency; Hydrogen; Instruments; Oscillators; Radio navigation; Resonance; Satellite navigation systems; Signal generators;
fLanguage :
English
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
Publisher :
ieee
ISSN :
0885-3010
Type :
jour
DOI :
10.1109/58.238107
Filename :
238107
Link To Document :
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