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| Titel |
Static and temporal gravity field recovery using grace potential difference observables |
| VerfasserIn |
S.-C. Han, C. Jekeli, C. K. Shum |
| 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 (2003-06-17), S.19-26 |
| Datensatznummer |
250000031
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| Publikation (Nr.) |
 copernicus.org/adgeo-1-19-2003.pdf |
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| Zusammenfassung |
The gravity field dedicated satellite missions like
CHAMP, GRACE, and GOCE are supposed to map the
Earth’s global gravity field with unprecedented accuracy and
resolution. New models of Earth’s static and time-variable
gravity field will be available every month as one of the science
products from GRACE. Here we present an alternative
method to estimate the gravity field efficiently using the in
situ satellite-to-satellite observations at the altitude and show
results on static as well as temporal gravity field recovery.
Considering the energy relation between the kinetic energy
of the satellite and the gravitational potential, the disturbing
potential difference observations can be computed from
the orbital parameter vectors in the inertial frame, using the
high-low GPS-LEO GPS tracking data, the low-low satelliteto-
satellite GRACE measurements, and data from 3-axis accelerometers
(Jekeli, 1999). The disturbing potential observation
also includes other potentials due to tides, atmosphere,
other modeled signals (e.g. N-body) and the geophysical
fluid signals (hydrological and oceanic mass variations),
which should be recoverable from GRACE mission
with a monthly resolution. The simulation results confirm
that monthly geoid accuracy is expected to be a few cm with
the 160 km resolution (up to degree and order 120) once other
corrections are made accurately. The time-variable geoids
(ocean and ground water mass) might be recovered with a
noise-to-signal ratio of 0.1 with the resolution of 800 km every
month assuming no temporal aliasing.
Key words. GRACE mission, Energy integral, Geopotential,
Satellite-to-satellite tracking, Temporal gravity field |
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