Second-degree Stokes coefficients from multi-satellite SLR

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • M. Bloßfeld - , Technische Universität München (Autor:in)
  • H. Müller - , Technische Universität München (Autor:in)
  • M. Gerstl - , Technische Universität München (Autor:in)
  • V. Štefka - , Czech Academy of Sciences (Autor:in)
  • J. Bouman - , Technische Universität München (Autor:in)
  • F. Göttl - , Technische Universität München (Autor:in)
  • M. Horwath - , Professur für Geodätische Erdsystemforschung (Autor:in)

Abstract

The long wavelength part of the Earth’s gravity field can be determined, with varying accuracy, from satellite laser ranging (SLR). In this study, we investigate the combination of up to ten geodetic SLR satellites using iterative variance component estimation. SLR observations to different satellites are combined in order to identify the impact of each satellite on the estimated Stokes coefficients. The combination of satellite-specific weekly or monthly arcs allows to reduce parameter correlations of the single-satellite solutions and leads to alternative estimates of the second-degree Stokes coefficients. This alternative time series might be helpful for assessing the uncertainty in the impact of the low-degree Stokes coefficients on geophysical investigations. In order to validate the obtained time series of second-degree Stokes coefficients, a comparison with the SLR RL05 time series of the Center of Space Research (CSR) is done. This investigation shows that all time series are comparable to the CSR time series. The precision of the weekly/monthly C21 and S21 coefficients is analyzed by comparing mass-related equatorial excitation functions χmass1,2 with geophysical model results and reduced geodetic excitation functions. In case of χmass1, the annual amplitude and phase of the DGFI solution agrees better with three of four geophysical model combinations than other time series. In case of χmass2, all time series agree very well to each other. The impact of C20 on the ice mass trend estimates for Antarctica are compared based on CSR GRACE RL05 solutions, in which different monthly C20 time series are used for replacing. We found differences in the long-term Antarctic ice loss of 12.3 Gt/year between the GRACE solutions induced by the different C20 SLR time series of CSR and DGFI, which is about 13 % of the total ice loss of Antarctica. This result shows that Antarctic ice mass loss quantifications must be carefully interpreted.

Details

OriginalspracheEnglisch
Seiten (von - bis)857–871
FachzeitschriftJournal of Geodesy
Jahrgang89
PublikationsstatusVeröffentlicht - Sept. 2015
Peer-Review-StatusJa

Externe IDs

Scopus 84941022547
ORCID /0000-0001-5797-244X/work/142246502

Schlagworte

Fächergruppen, Lehr- und Forschungsbereiche, Fachgebiete nach Destatis

ASJC Scopus Sachgebiete

Schlagwörter

  • Multi-satellite SLR, Stokes coefficients, C20, Lageos, Equatorial excitation functions, Antarctic ice mass loss