Validation of GOCE/GRACE satellite only and combined global geopotential models over Greece in the frame of the GOCESeaComb project
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Ημερομηνία
2015-01
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Δικαιώματα
Attribution-NonCommercial-NoDerivatives 4.0 Διεθνές
Άδειες
Παραπομπή
Παραπομπή
Περίληψη
The GOCESeaComb project, funded by ESA in the frame of the PRODEX program, aims to
utilize GOCE data within combination schemes in order to achieve high-quality and accuracy
predictions related to Earth’s gravity field, sea level and dynamic ocean topography. In this work
the results from the detailed validation of the latest GOCE, GOCE/GRACE and combined global
geopotential models are presented referring to the fourth release of the models and the various
strategies (TIM, DIR, GOCO, EIGEN-S/c) employed for their determination. The validation is
performed following two approaches. The first one refers to the evaluation of the GGMs signal
and error in the form of the provided degree and error variances. The second refers to an external
evaluation of the GGMs against local gravity, GPS/Leveling data and deflections of the vertical. In
this validation step we follow a spectral enhancement approach of GOCE GGMs, where EGM08 is
used to fill-in the medium and high-frequency content along with RTM effects for the high and
ultra high part. From the evaluation with GPS/Levelling benchmarks, it is concluded that the
GOCE/GRACE GGMs provide improved accuracies compared to EGM2008 by about 2 cm in the
spectral range between d/o 120-230. Finally, GOCE/GRACE GGMs manage to provide the same,
as EGM2008, level of reduction to the local gravity anomalies, with a standard deviation at the
6.1-6.2 mGal level and marginally better residuals, at the sub-arcsec level in the reduction of
deflections of the vertical.