| Determining marine gravity precisely is one of the important problems in the marine geodesy.Nowadays, marine gravity has a wide range of applications. The high precise marine gravity data can be used to elaborate the Earth gravity field model, to inverse the structures in the interior of the Earth, to search mineral deposits and to describe of the geological structure, can also provide information to support for the safe navigation of underwater vehicles and other platforms. With the rapid development of the marine surveying theory and technology, the traditional ship marine gravity surveying had been difficult to meet the requirements of fast surveying and mapping for global ocean. There are little measured gravity data on vast sea, especially a few ocean deep water areas, gravity surveying is still blank. Satellite altimetry technology was born at the historic moment in the 1970s, which had the high accuracy of observation, short data cycle and high coverage, and a series of technical incomparable characteristics on the ground, as well as GPS caused a profound change in the measurement industry. The main research work in this dissertation comprises the following parts:Firstly, thinking about the actual application, the basic mathematical model of satellite altimetry was described, the error elements in raw data and the integral approach were introduced briefly in the first. The grid problem of satellite altimetry data was carried on the thorough discussion. And,this paper put forward the data gridding method in the frequency domain. The numerical calculation showed that utilizing the kernel function without confusion in frequency domain, and grid data of high frequency signals can be filtered out the Nyquist frequency limit outside, avoid confusion and position deviation, improve the operation speed, reduce memory consumption.Secondly, the method of calculating vertical deflection of sea was researched based on satellite altimetry data. Combined with Geosat GM, ERS-1, T/P, T/P new orbit, ERS-2, GFO altimetry data and other multi-generation offshore,China adjacent waters (00°?45°N,1000°?150°E) 2'× 2'meridian vertical deviation model grid resolution and prime vertical deflection of the vertical model were built. Compared to the internationally recognized deflection of the vertical accuracy better CLS_SHOW99 model comparison, RMS on the meridian component is 0.78", RMS in the prime vertical component of 1.25". The model of deflection vertical established in this paper basically is reached the accuracy CLS_SHOW99 model of the vertical deflection.Thirdly, the three basic methods of data retrieval were researched based on satellite altimetry gravity anomaly, namely the anti-Stokes numerical solution of equations, analytical inverse solution Stokes equations and inverse Vening-Meinesz formula. Based on the China coastal waters and adjacent satellite altimetry data by inversion calculation and ship measurement, vertical deviation waters numerical model,near China coastal waters and adjacent waters(0°? 45°N,100°?150°E)gridded by 2 '× 2' resolution, was computed by the inverse Vening-Meinesz method. Compared with the accuracy of the ship gravity anomaly, the RMS by the proposed method in this paper is 3.92 mGal.Finally, as to the selection of matching navigation area in the underwater targets' positioning and moving, according to the three indicators, that is local standard deviation of gravity field, local gravity field correlation coefficient, and local gravity field slope, matching navigation area were determined near the Chinese sea waters with the inversing marine data from the satellite altimetry. |
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