Summary:

Regarding the rapidly growing satellite altimetry database and correspond-ing products worldwide, an investigation of different mean dynamic ocean topog-raphy (MDT) models was assessed to be important for further use in geodetic ap-plications. The efficiency and quality of different MDT models are discussed in view of adopted geoids as reference surfaces. The models used are: 1) The ECCO model based on hydrology and altimetry data, 2) The combined MDT Rio-05 con-structed in CSL AVISO (2005) from data for the period 1993-1999, 3) The com-bined MDT CNES-CLS09 model at the grid points 15'x15' based on altimetry and hydrology data for the period 1993-2007 (CSL AVISO, 2009), 4) The DNSC08MDT solution of mean dynamic topography (Danish National Space Cen-ter) obtained from the geometrical differences between the DNSC08 mean sea sur-face and the EGM2008 geoid model.
The concluding results of the investigation are: 1) statistics of all mean
dyamic topography models leads to the approximately same standard deviations about 70 cm and range from -2 m to 2 m; 2) all differences among various MDT models give much smaller standard deviations about 6 - 15 cm; 3) all such differ-ences among various MDT give larger mean deviation, which can be explained by different geoid models or reference surfaces adopted for each solution; 4) better agreement provides MDT CNES-CLS09 and DNSC08MDT models. As a result, we prefer MDT CNES-CLS09 and DNSC08MDT solutions since their noise level corresponds to an estimated accuracy of modern satellite altimetry data.