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| Titel |
Astrogeodetic Geoid for Austria using Least-Squares Prediction Technique for Densifying the Deflections |
| VerfasserIn |
Hussein Abd-Elmotaal, Norbert Kühtreiber |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250072095
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| Zusammenfassung |
| Astrogeodetic geoid determination technique is the most precise geoid determination technique if sufficient deflection data are well distributed for the area of interest. Such condition is not generally achieved in practice. Different techniques were proposed to densify the deflection data, among which is the astrogravimetric geoid determination technique. The paper presents a technique for densifying the deflection data using least-squares prediction technique. The available data sets are described. The window remove-restore technique (Abd-Elmotaal and Kuehtreiber, 2003) has been used. The available deflections of the vertical have been topographically-isostatically reduced using the Airy isostatic hypothesis. The reduced deflections have been used to interpolate deflections on a relatively dense grid covering the data window using the least-squares prediction technique. These gridded reduced deflections have been used to compute an astrogeodetic geoid for Austria using least-squares collocation technique within the remove-restore scheme. For the sake of comparison, an astrogeodetic geoid has been computed using the original deflections of the vertical data without densification. All computed geoids have been fitted to the GPS/levelling derived geoid. A wide comparison among the derived geoids computed within the current investigation has been carried out. |
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