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Shipboard Gravimetric Data and GEOSAT-44 Data - A Comparison
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 2nd International Congress of the Brazilian Geophysical Society, Oct 1991, cp-316-00022
Abstract
Radar altimetry from existing satellite data sources can be employed to estimate accurately both the geoid height and anomalous horizontal component of the earth's gravity field. With more extended satellite coverage, the vertical component can, likewise, be accurately estimated. Thus, the noise problems inherent in terrestial (sea) measurements of the earth's vertical field can be minimized and accurate geophysical maps of the ocean's free-air gravity field can yield valuable information. The deviations between the satellite data and ship survey data need, however, to be quantified. Studies to date of the correlation between terrestial and satellite data have not been able to accurately predict the correlation (or lack of it) because of the sparcely sampled nature of both ship survey and satellite data. In this paper, we investigate a comparison between both the geoid height and the anomalous horizontal component of the earth's gravity field as determined from both relatively close spaced ship survey data and data from the GEOSAT-44 satellite data base. The data resolution appears to be limited by surface data interpola.tion and location inaccuracies, near coast tidal effects, and some effects related to the satellite data..