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Titel |
Globally covering a-priori regional gravity covariance models |
VerfasserIn |
D. Arabelos, C. C. Tscherning |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7340
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Digitales Dokument |
URL |
Erschienen |
In: G1. The new gravity field mission (CHAMP, GRACE, GOCE): from measurements to geophysical interpretation ; Nr. 1 (2003-08-12), S.143-147 |
Datensatznummer |
250000043
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Publikation (Nr.) |
copernicus.org/adgeo-1-143-2003.pdf |
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Zusammenfassung |
Gravity anomaly data generated using Wenzel’s
GPM98A model complete to degree 1800, from which
OSU91A has been subtracted, have been used to estimate covariance
functions for a set of globally covering equal-area
blocks of size 22.5° × 22.5° at Equator, having a 2.5° overlap.
For each block an analytic covariance function model
was determined. The models are based on 4 parameters:
the depth to the Bjerhammar sphere (determines correlation),
the free-air gravity anomaly variance, a scale factor
of the OSU91A error degree-variances and a maximal summation
index, N, of the error degree-variances. The depth
of Bjerhammar-sphere varies from -134km to nearly zero,
N varies from 360 to 40, the scale factor from 0.03 to 38.0
and the gravity variance from 1081 to 24(10µms-2)2. The
parameters are interpreted in terms of the quality of the data
used to construct OSU91A and GPM98A and general conditions
such as the occurrence of mountain chains. The variation
of the parameters show that it is necessary to use regional
covariance models in order to obtain a realistic signal
to noise ratio in global applications.
Key words. GOCE mission, Covariance function, Spacewise
approach` |
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