Search Results

You are looking at 1 - 5 of 5 items for :

  • "Earth gravity" x
  • Refine by Access: All Content x
Clear All

The assessment of the results achieved in our division at the field of physical geodesy is summarised. The studies at the fields of Earth rotation, Earth tides, Earth gravity and the global and regional Earth deformations related to geodesy and geodynamics are presented by citation of the most important publications and dissertations, which cover the history of our institute. The paper ends with the case study related to the newly developed full roving GPS observation strategy.

Restricted access

Loránd Eötvös' torsion balance yields the local structure of the earth's gravity field with very high precision, still comparable to present days standards. The recently launched NASA satellite mission GRACE and the approved ESA mission GOCE (launch in 2005) apply the same measurement principle in space. It counteracts the natural attenuation  with growing distance from the earth's surface of the gravitational attraction. As a consequence, even from space the global gravity field will be mapped with unprecedented resolution and accuracy. Also temporal variations due to mass changes in the atmosphere, oceans, ice covers, groundwater tables and inside the earth are expected to be discernible. Geodesy, solid earth physics, oceanography and sea level research will greatly benefit from the detailed knowledge of the earth's gravity field.

Restricted access

There are numerous methods to modify Stokes’ formula with the usually common feature of reducing the truncation error committed by the lack of gravity data in the far-zone, resulting in an integral formula over the near-zone combined with an Earth Gravity Model that mainly contributes with the long-wavelength information. Here we study the reverse problem, namely to estimate the geoid height with data missing in a cap around the computation point but available in the far-zone outside the cap. Secondly, we study also the problem with gravity data available only in a spherical ring around the computation point. In both cases the modified Stokes formulas are derived using Molodensky and least squares types of solutions. The numerical studies show that the Molodensky type of modification is useless, while the latter method efficiently depresses the various errors contributing to the geoid error. The least squares methods can be used for estimating geoid heights in regions with gravity data gaps, such as in Polar Regions, over great lakes and in some developing countries with lacking gravity data.

Restricted access

, and g → the earth's gravity.   R I B is the rotation matrix, which makes it possible to project g → from the terrestrial inertial frame of reference to the frame of reference of the moving body. All vectors are oriented according to the North

Open access

of Mankiw: “Economists try to address their subject with a scientist's objectivity…This (the scientific, J.D.) method of inquiry is applicable to studying a nation's economy as it is to studying the earth's gravity or a species' evolution” ( Mankiw

Restricted access