Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-25T16:11:01.065Z Has data issue: false hasContentIssue false
  • English
  • Français

Polar Coordinates and UT1 - UTC from PZT Observations

Published online by Cambridge University Press:  14 August 2015

D. Djurovic
D. Djurovic*
Affiliation:
Department of Astronomy, Belgrade, Yugoslavia

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Use of new techniques (Doppler, laser, VLBI) has yielded such results that many astronomers believe that in the near future these techniques will replace classical instruments for observations of the Earth's rotation. None of the modern techniques has furnished observational series which demonstrate that systematic errors in the polar coordinates and UT1 are stable over sufficiently long intervals. Investigations of known phenomena such as sudden changes of the secular term in UT1 - UTC (Munk and MacDonald, 1960), changes of the amplitude and phase of the seasonal irregularities (Fliegel and Hawkins, 1967; Pavlov and Staritzin, 1962), secular motion of the mean pole (Mihailov, 1971; Markowitz, 1960), continental drift (Stoyko, 1938; Djurovic, 1976), quasi-diurnal nutation of Molodenskij (Popov, 1963; Toomre, 1974; Rochester et al., 1974), etc., are complicated by the existence of systematic error variations (accuracy), and to a smaller degree, on the accidental errors (precision). The BIH and IPMS make use of individual series of astronomical latitude. ϕi, and (UTO - UTC)i from up to 82 classical instruments (Guinot, 1976). If the systematic errors in these series are independent, the polar coordinates and UT1 - UTC determined from a combination of observational series would result in an improvement of accuracy by at least one order of magnitude through the mutual compensation of the variation in systematic errors. At present, however, it is uncertain whether mutual independence of modern observations (a basic condition for mutual compensation of errors) will be better than that of the classical instruments.

Type
Part I: Time
Information
Symposium - International Astronomical Union , Volume 82: Time and the Earth's Rotation , 1979 , pp. 75 - 78
Copyright
Copyright © Reidel 1979 

References

Djurovic, D.: 1975a, Bull. Obs. Astron. Belgrade 126, p. 62.Google Scholar
Djurovic, D.: 1975b, Bull. d'Observations, Obs. Royal Belgium 4, fasc. 3, p. 17.Google Scholar
Djurovic, D.: 1976, Bull. Accad. Serbe Sc. et Arts 55, no. 9, p. 7.Google Scholar
Djurovic, D.: 1978, Publ. Depart. Astron. Belgrade 8, p. 5.Google Scholar
Fliegel, H. F., and Hawkins, T. P.: 1967, Astron. J. 72, p. 544.CrossRefGoogle Scholar
Guinot, B.: 1976, Report presented to IAU General Assembly, Grenoble.Google Scholar
Markowitz, W.: 1960, in Runcorn, S. K. (ed.), “Methods and Techniques in Geophysics”, Intersciences Publishers Ltd., London.Google Scholar
Mihailov, A. A.: 1971, Astron. Zhurn. Akad. Naouk SSSR 48, no. 6, p. 1301.Google Scholar
Munk, W. H., and MacDonald, G. J. F.: 1960, “The Rotation of the Earth”, Cambridge University Press, London.Google Scholar
Pavlov, N. N., and Staritzin, G. V.: 1962, Astron. Zhurn. Akad. Naouk SSSR 39, no. 1, p. 123.Google Scholar
Popov, N. A.: 1963, Astron Zhurn. Akad. Naouk SSSR 7, p. 422.Google Scholar
Rochester, M. G., Jensen, O. G., and Smylie, D. E.: 1974, Geophys. J. Roy. Astron. Soc. 38, p. 349.CrossRefGoogle Scholar
Stoyko, N.: 1938, Acta Astron. 3, p. 97.Google Scholar
Toomre, A.: 1974, Geophys. J. Roy. Astron. Soc. 38, p. 335.CrossRefGoogle Scholar