The general objective of COTAGA is to provide the most precise global ocean tide models, EOTxx, estimated by common analysis of multi-mission satellite altimetry and long-term GRACE observations in order to combine in an optimal sense short and long-wavelength signals of the major ocean tide constituents. EOTxx shall provide the most comprehensive and up-to-date description of tidal mass variations, become a candidate for the standard processing schemes in satellite altimetry, GRACE and GOCE processing (e.g. GRACE release 06), as well as for many other applications (ocean dynamics, tidal dissipation, Earth rotation, loading effects) in Earth system sciences. COTAGA is a joint project of the following institutions:

• Institute of Geodesy, Graz University of Technology, Austria
• Deutsches Geodätisches Forschungsinstitut München (DGFI)
• Deutsches GeoForschungszentrum Potsdam (GFZ)