Determining the Gravitational Gradient Tensor Using Satellite-Altimetry Observations over the Persian Gulf |
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| Authors: | A Safari M A Sharifi H Amin R Tenzer |
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| Institution: | 1. Department of Surveying and Geomatics Engineering, University College of Engineering, University of Tehran, Iran;2. Institute of Geodesy and Geophysics, School of Geodesy and Geomatics, Wuhan University, Wuhan, China |
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| Abstract: | With the advent of satellite altimetry in 1973, new scientific applications became available in oceanography, climatology, and marine geosciences. Moreover, satellite altimetry provides a significant source of information facilitated in the geoid determination with a high accuracy and spatial resolution. The information from this approach is a sufficient alternate for marine gravity data in the high-frequency modeling of the marine gravity field quantities. The gravity gradient tensor, consisting of the second-order partial derivatives of the gravity potential, provides more localized information than gravity measurements. Marine gravity observations always carry a high noise level due to environmental effects. Moreover, it is not possible to model the high frequencies of the Earth's gravity field in a global scale using these observations. In this article, we introduce a novel approach for a determination of the gravity gradient tensor at sea level using satellite altimetry. Two numerical techniques are applied and compared for this purpose. In particular, we facilitate the radial basis functions (RBFs) and the harmonic splines. As a case study, the gravitational gradient tensor is determined and results presented in the Persian Gulf. Validation of results reveals that the solution of the harmonic spline approach has a better agreement with a theoretical zero-value of the trace of the Marussi gravitational gradient tensor. However, the data-adaptive technique in the RBF approach allows more efficient selection of the parameters and 3-D configuration of RBFs compared to a fixed parameterization by the harmonic splines. |
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| Keywords: | Satellite altimetry marine geoid gravitational gradient tensor radial basis functions gravity anomaly harmonic splines |
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