Abstract In the frame of “Modernization Hellenic Gravity Network - ModernGravNet” project, relative and absolute gravity measurements were carried out at selected 1st 2nd order benchmarks network. These are used first for evaluation Then, as official network values referenced to Potsdam system, transformation parameters determined converting new system it is defined by measurements. A northeast...

Since 2006, several different groups have computed geoid and/or quasigeoid (quasi/geoid) models for the Auvergne test area in central France using various approaches. In this contribution, we compute and compare Curtin University of Technology’s Swedish Royal Institute These approaches differ many ways, such as their treatment input data, choice type spherical harmonic model (combined or satell...

The geoid-to-quasigeoid correction has been traditionally computed approximately as a function of the planar Bouguer gravity anomaly and the topographic height. Recent numerical studies based on newly developed theoretical models, however, indicate that the computation of this correction using the approximate formula yields large errors especially in mountainous regions with computation points ...

We analyze the effect of seismic activity on sealevel variations, by computing the time-dependent vertical crustal movement and geoid change due to coseismic deformations and postseismic relaxation effects. Seismic activity can affect both the absolute sealevel, by changing the Earth gravity field and hence the geoid height, and the relative sealevel, i.e. the radial distance between seafloor a...

The increased use of GNSS for technical constructions and infrastructure works makes necessary the calculation of local accurate geoid undulation’s models for the determination of accurate orthometric heights. Apart from the conventional methods, artificial neural networks (ANN) are also used for this purpose. Specially, back propagation artificial neural networks (BPANN) are widely applied for...

One main geodetic objective of the European Space Agency’s satellite mission GOCE (gravity eld and steady-state ocean circulation explorer) is the contribution to global height system uni cation. This can be achieved by applying the Geodetic Boundary Value Problem (GBVP) approach. Thereby one estimates the unknown datum offsets between different height networks (datum zones) by comparing the ph...

Three GOCE-based gravity field solutions have been computed by ESA’s high-level processing facility and were released to the user community. All models are accompanied by variance-covariance information resulting either from the least squares procedure or a Monte-Carlo approach. In order to obtain independent external quality parameters and to assess the current performance of these models, a s...

S U M M A R Y Our understanding of mantle convection and the motion of plates depends intimately on our understanding of the viscosity structure of the mantle. While geoid and gravity observations have provided fundamental constraints on the radial viscosity structure of the mantle, the influence of short-wavelength variations in viscosity is still poorly understood. We present 2-D and 3-D fini...