Premium
Temporal variations in low degree zonal harmonics from Starlette orbit analysis
Author(s) -
Cheng M. K.,
Eanes R. J.,
Shum C. K.,
Schutz B. E.,
Tapley B. D.
Publication year - 1989
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl016i005p00393
Subject(s) - satellite laser ranging , harmonics , degree (music) , geodesy , physics , secular variation , orbit (dynamics) , satellite , orbit determination , atmospheric sciences , laser ranging , geology , geophysics , astronomy , laser , engineering , quantum mechanics , voltage , aerospace engineering , acoustics , optics
The dynamical effect of temporal variations in the zonal harmonics of the Earth's gravitational potential due to tidal and meteorological mass redistribution has been observed using satellite laser ranging (SLR) measurements to Starlette. The secular variations in the Earth's zonal harmonics,J . 1 , and the year‐to‐year fluctuation of the even degree annual and semi‐annual tides ( S a and S sa ) have been determined from a continuous Starlette orbit spanning from 1983 through 1985. When variations in higher degree zonals are assumed to be zero and the 18.6‐year tide is fixed to an equilibrium value, the results are:J . 2 = ( −2.5 ± 0.3 ) ,J . 3 = ( −0.1 ± 0.3 ) ,J . 4 = ( 0.3 ± 0.6 ) , in units of 10 −11 yr −1 . The Starlette‐derivedJ . 2is in good agreement with the value observed from Lageos and values predicted from postglacial rebound. The mean values for S a and S sa tides are in good agreement with other tide solutions. The year‐to‐year fluctuations of the even degree S a , deduced from Starlette node variations, are about 25% of the mean value obtained during the three‐year Starlette orbit span.