Details
| Original language | English |
|---|---|
| Pages (from-to) | 195-203 |
| Number of pages | 9 |
| Journal | Bollettino di Geofisica Teorica ed Applicata |
| Volume | 40 |
| Issue number | 3-4 |
| Publication status | Published - 1999 |
Abstract
Masses associated with the local topography are a dominant source of short wavelength gravity field variations. In the modeling of the gravity field it is thus an advantage to eliminate the effect of the terrain in a remove-restore procedure. In this process, terrain reductions are computed for the observation stations at the Earth's surface, considering either the complete topography, the topography and its isostatic compensation, or the residual topography (RTM technique). Hence, the reduced gravity field observations are referring to the actual ground level. Therefore, Molodensky's theory, considering data on non-level surfaces, should be applied in the traditional gravity field modeling approaches, while in collocation this is handled directly through height dependent covariance functions. In this paper, we provide numerical examples for the computation of the Molodensky series terms associated with the traditionally unreduced observations as well as in connection with various terrain-reduced data. Due to the smoothing, resulting from the terrain reductions, the magnitude of the Molodensky terms is reduced as well and the series convergence is improved. The computations are based on the Fast Fourier Transform (FFT) technique. The numerical tests are done in a mountainous area of the European Alps. The terrain data are on grids with various grid spacings starting at a resolution of 200 m. One of the main goals of this study is to investigate the magnitude of the Molodensky terms with regard to the computation of an improved European quasigeoid model.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Oceanography
- Earth and Planetary Sciences(all)
- Geophysics
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In: Bollettino di Geofisica Teorica ed Applicata, Vol. 40, No. 3-4, 1999, p. 195-203.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Investigation of the Molodensky series terms for terrain reduced gravity field data
AU - Denker, H.
AU - Tziavos, I. N.
N1 - Copyright: Copyright 2013 Elsevier B.V., All rights reserved.
PY - 1999
Y1 - 1999
N2 - Masses associated with the local topography are a dominant source of short wavelength gravity field variations. In the modeling of the gravity field it is thus an advantage to eliminate the effect of the terrain in a remove-restore procedure. In this process, terrain reductions are computed for the observation stations at the Earth's surface, considering either the complete topography, the topography and its isostatic compensation, or the residual topography (RTM technique). Hence, the reduced gravity field observations are referring to the actual ground level. Therefore, Molodensky's theory, considering data on non-level surfaces, should be applied in the traditional gravity field modeling approaches, while in collocation this is handled directly through height dependent covariance functions. In this paper, we provide numerical examples for the computation of the Molodensky series terms associated with the traditionally unreduced observations as well as in connection with various terrain-reduced data. Due to the smoothing, resulting from the terrain reductions, the magnitude of the Molodensky terms is reduced as well and the series convergence is improved. The computations are based on the Fast Fourier Transform (FFT) technique. The numerical tests are done in a mountainous area of the European Alps. The terrain data are on grids with various grid spacings starting at a resolution of 200 m. One of the main goals of this study is to investigate the magnitude of the Molodensky terms with regard to the computation of an improved European quasigeoid model.
AB - Masses associated with the local topography are a dominant source of short wavelength gravity field variations. In the modeling of the gravity field it is thus an advantage to eliminate the effect of the terrain in a remove-restore procedure. In this process, terrain reductions are computed for the observation stations at the Earth's surface, considering either the complete topography, the topography and its isostatic compensation, or the residual topography (RTM technique). Hence, the reduced gravity field observations are referring to the actual ground level. Therefore, Molodensky's theory, considering data on non-level surfaces, should be applied in the traditional gravity field modeling approaches, while in collocation this is handled directly through height dependent covariance functions. In this paper, we provide numerical examples for the computation of the Molodensky series terms associated with the traditionally unreduced observations as well as in connection with various terrain-reduced data. Due to the smoothing, resulting from the terrain reductions, the magnitude of the Molodensky terms is reduced as well and the series convergence is improved. The computations are based on the Fast Fourier Transform (FFT) technique. The numerical tests are done in a mountainous area of the European Alps. The terrain data are on grids with various grid spacings starting at a resolution of 200 m. One of the main goals of this study is to investigate the magnitude of the Molodensky terms with regard to the computation of an improved European quasigeoid model.
UR - http://www.scopus.com/inward/record.url?scp=0005847320&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:0005847320
VL - 40
SP - 195
EP - 203
JO - Bollettino di Geofisica Teorica ed Applicata
JF - Bollettino di Geofisica Teorica ed Applicata
SN - 0006-6729
IS - 3-4
ER -