Lustrumboek "The 5th Element"
The aim must be to move the dark line in figure 2 further to the right. This will be
achieved by the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE)
mission, the first core mission within the European Space Agency (ESA) Earth Explorer
Programme to be launched in 2004. More precise, the aim of GOCE is to determine
the global gravity field with a resolution of 100 km or better and a global
homogeneous accuracy of (MO)xlO5 m/s2 and 1 - 5 cm in terms of gravity
anomalies and geoid heights, respectively (cf. figure 3). This is an improvement of
the resolution with a factor 3 to 4 and of the accuracy of several orders of magnitude
over the state-of-the-art global gravity field models.
2
CT>
•a
Trenches
Basing
10.10
8.10
6.10
4.10
2.10
1000 100 10
Horizontal Resolution in km
Figure 2. Required accui ocy as function of horizontal resolution necessa/y to resolve
various geophysical features
Accuracy
Spatial Resolution
Geoid
Gravity
(half wavelength)
Ocean Circulation
- Small scale
- Bassin scale
2 cm
<1 cm
60-250 km
1000 km
Geodynamics
- Continental lithosphere (thermal structure,
post-glacial rebound)
- Mantle composition, rheology
- Ocean lithosphere and interaction with
asthenosphere (subduction processes)
1-2 10"5m/s2
1-2 10"5m/s2
5-10 10"5m/s2
50-400 km
100-5000 km
100-200 km
Geodesie
- Ice and land vertical movements
- Rock basement under polar ice sheets
- World-wide height system
2 cm
<5 cm
1-5 10"5m/s2
100-200 km
50-100 km
50-100 km
Figure 3: GOCE scientific requirements
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