TY - JOUR
T1 - Contribution of satellite laser ranging to combined gravity field models
AU - Maier, Andrea
AU - Krauss, Sandro
AU - Hausleitner, Walter
AU - Baur, Oliver
N1 - Funding Information:
This work was funded by the Austrian Space Application Programme No. 6 (Project ID 819685) of the Austrian Research Promotion Agency (FFG), supported by the Federal Ministry for Transport, Innovation and Technology (BMVIT). We thank Despina Pavlis and John McCarthy for supply and support concerning the software packages GEODYN and SOLVE. Comments and suggestions by two anonymous reviewers are acknowledged.
PY - 2012/2/1
Y1 - 2012/2/1
N2 - In the framework of satellite-only gravity field modeling, satellite laser ranging (SLR) data is typically exploited to recover long-wavelength features. This contribution provides a detailed discussion of the SLR component of GOCO02S, the latest release of combined models within the GOCO series. Over a period of five years (January 2006 to December 2010), observations to LAGEOS-1, LAGEOS-2, Ajisai, Stella, and Starlette were analyzed. We conducted a series of closed-loop simulations and found that estimating monthly sets of spherical harmonic coefficients beyond degree five leads to exceedingly ill-posed normal equation systems. Therefore, we adopted degree five as the spectral resolution for real data analysis. We compared our monthly coefficient estimates of degree two with SLR and Gravity Recovery and Climate Experiment (GRACE) time series provided by the Center for Space Research (CSR) at Austin, Texas. Significant deviations in C 20 were noted between SLR and GRACE; the agreement is better for the non-zonal coefficients. Fitting sinusoids together with a linear trend to our C 20 time series yielded a rate of (-1.75 ± 0.6) × 10 -11 /yr; this drift is equivalent to a geoid change from pole to equator of 0.35 ± 0.12 mm/yr or an apparent Greenland mass loss of 178.5 ± 61.2 km 3 /yr. The mean of all monthly solutions, averaged over the five-year period, served as input for the satellite-only model GOCO02S. The contribution of SLR to the combined gravity field model is highest for C 20 , and hence is essential for the determination of the Earth's oblateness.
AB - In the framework of satellite-only gravity field modeling, satellite laser ranging (SLR) data is typically exploited to recover long-wavelength features. This contribution provides a detailed discussion of the SLR component of GOCO02S, the latest release of combined models within the GOCO series. Over a period of five years (January 2006 to December 2010), observations to LAGEOS-1, LAGEOS-2, Ajisai, Stella, and Starlette were analyzed. We conducted a series of closed-loop simulations and found that estimating monthly sets of spherical harmonic coefficients beyond degree five leads to exceedingly ill-posed normal equation systems. Therefore, we adopted degree five as the spectral resolution for real data analysis. We compared our monthly coefficient estimates of degree two with SLR and Gravity Recovery and Climate Experiment (GRACE) time series provided by the Center for Space Research (CSR) at Austin, Texas. Significant deviations in C 20 were noted between SLR and GRACE; the agreement is better for the non-zonal coefficients. Fitting sinusoids together with a linear trend to our C 20 time series yielded a rate of (-1.75 ± 0.6) × 10 -11 /yr; this drift is equivalent to a geoid change from pole to equator of 0.35 ± 0.12 mm/yr or an apparent Greenland mass loss of 178.5 ± 61.2 km 3 /yr. The mean of all monthly solutions, averaged over the five-year period, served as input for the satellite-only model GOCO02S. The contribution of SLR to the combined gravity field model is highest for C 20 , and hence is essential for the determination of the Earth's oblateness.
KW - GOCO
KW - Gravity field
KW - Satellite laser ranging
KW - Temporal variation
UR - http://www.scopus.com/inward/record.url?scp=84855796349&partnerID=8YFLogxK
U2 - 10.1016/j.asr.2011.10.026
DO - 10.1016/j.asr.2011.10.026
M3 - Article
AN - SCOPUS:84855796349
SN - 0273-1177
VL - 49
SP - 556
EP - 565
JO - Advances in Space Research
JF - Advances in Space Research
IS - 3
ER -
