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Observed tidal braking in the earth/moon/sun systemThe low degree and order terms in the spherical harmonic model of the tidal potential were observed through the perturbations which are induced on near-earth satellite orbital motions. Evaluations of tracking observations from 17 satellites and a GEM-T1 geopotential model were used in the tidal recovery which was made in the presence of over 600 long-wavelength coefficients from 32 major and minor tides. Wahr's earth tidal model was used as a basis for the recovery of the ocean tidal terms. Using this tidal model, the secular change in the moon's mean motion due to tidal dissipation was found to be -25.27 + or - 0.61 arcsec/century-squared. The estimation of lunar acceleration agreed with that observed from lunar laser ranging techniques (-24.9 + or - 1.0 arcsec/century-squared), with the corresponding tidal braking of earth's rotation being -5.98 + or - 0.22 X 10 to the -22 rad/second-squared. If the nontidal braking of the earth due to the observed secular change in the earth's second zonal harmonic is considered, satellite techniques yield a total value of the secular change in the earth's rotation rate of -4.69 + or - 0.36 X 10 to the -22 rad/second-squared.
Document ID
19880054600
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Christodoulidis, D. C.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Smith, D. E.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Williamson, R. G.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Klosko, S. M.
(EG & G, Inc. Lanham, MD, United States)
Date Acquired
August 13, 2013
Publication Date
June 10, 1988
Publication Information
Publication: Journal of Geophysical Research
Volume: 93
ISSN: 0148-0227
Subject Category
Geophysics
Accession Number
88A41827
Distribution Limits
Public
Copyright
Other

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