DocumentCode :
2601166
Title :
Optimum precise-clocks synthesis
Author :
Zhu, Shouhong
Author_Institution :
Shaanxi Astron. Obs., Chinese Acad. of Sci., Xian, China
fYear :
1997
fDate :
28-30 May 1997
Firstpage :
422
Lastpage :
427
Abstract :
Precise-clocks synthesis can be regarded as the formation of a more stable time scale by synthesizing as many precise-clocks as possible. According to J.A. Barnes´ power-law model (1971) we know that the precise-clock noise contains five independent noise parts, each of which corresponds to one unique source-white-noise, and these source-white-noises are the main factors resulting in the instability of the precise-clock. So the key of precise-clocks synthesis is to control every source-white-noise by utilizing its time-domain differences among contributing precise-clocks. Optimum precise-clocks synthesis is equivalent to the estimation of every source-white-noise difference between ideal clock and reference clock, and the data we can use is clock difference between each contributing clock and reference clock. There are several difficulties in the conversion from optimum principle to optimum algorithm. In this paper the author overcame these difficulties and then presented a useful algorithm of precise-clocks synthesis through following procedure: firstly, to estimate correlation matrix of each source-white-noise; secondly, to separate (according to noise part) clock difference series between each contributing clock and reference clock; thirdly, to weighted-average every source-white-noise with its corresponding group of weights. The result of emulation computation on simulated data demonstrated that this algorithm is optimum. The result of emulation computation on three years of real data also demonstrated that the algorithm is effective
Keywords :
clocks; correlation methods; digital simulation; estimation theory; frequency stability; matrix algebra; measurement standards; simulation; smoothing methods; spectral analysis; time measurement; white noise; correlation matrix; emulation computation; estimation; instability; optimum algorithm; power-law model; precise-clock noise; precise-clocks synthesis; simulated data; source-white-noise; stable time scale; time keeping; time-domain differences; weighted averaging; white-noise; working clock; Clocks; Computational modeling; Emulation; Frequency synthesizers; Kalman filters; Logic; Observatories; Random processes; Smoothing methods; Time domain analysis;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Frequency Control Symposium, 1997., Proceedings of the 1997 IEEE International
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-3728-X
Type :
conf
DOI :
10.1109/FREQ.1997.638638
Filename :
638638
Link To Document :
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