An overview of spectral methods for the optimal processing of satellite altimetry and other data
Ilias N. Tziavos(1) , Michael G. Sideris(2) , Georgios S. Vergos(1) , Vassilios N. Grigoriadis(1) , and Vassilios D. Andritsanos(1)
Aristotle University of Thessaloniki,
(2) University of Calgary, 2500 University Drive N.W., T2N 1N4, Clagary, AB, CANADA
This paper summarizes the results obtained and the improvements achieved during the last fifteen years of satellite altimetry research by spectral combination methods at the Universities of Calgary and Thessaloniki. In particular, a review of the principles and characteristics of the FFT-based multiple input-output system theory method is presented, with applications in marine gravity and geoid, sea surface topography, and bathymetry modeling by an optimal combination of satellite altimetry and other (e.g., shipborne gravity, bathymetry, etc.) data. The main focus is placed on the contributions of geodetic mission altimetry from ERS1, as well as from multi-satellite altimetry data processing, with and without the use of additional data, including error propagation. Furthermore, a comparison to the least squares collocation method, and the results obtained by it, is made from both the theoretical and practical point of view. Numerical results are shown for the areas offshore Canada and in the Mediterranean Sea. Finally, conclusions are drawn on the improvement in the determination of various gravity field related quantities in terms of accuracy and resolution by combining altimetric and other observations.