Exploiting the full potential of ocean tide models for space geodetic techniques

The influence of ocean tides plays a major role for geodetic space methods in the modeling of satellite orbits, Earth rotation, and short-period station motions.

Current ocean tide models are published with a large number of individual constituents that are representative for the entire tidal spectrum. The analysis requires interpolation of the constituents onto the spectrum using admittance theory. The application of admittance is non-trivial, as it explicitly and implicitly refers to historical conventions that are hard to retrace for users. Further linear admittance theory is non-unique and requires some insight into the principles of ocean tidal dynamics.

Nonetheless, the error-prone implementation of admittance is mostly left to the user, which can easily induce confusion and errors. For example, the IERS2010 conventions describe only one method for the outdated FES2004 model that does not apply directly to current models. While there is a conventional routine for calculating the ocean loading displacement, it needs to consider recent developments and therefore does not exploit the full potential of current ocean tide models.

In this presentation, a unified approach is presented for discussion to exploit the full potential of current ocean tide models in satellite orbit calculation and for station displacements. This approach aims to set up a framework for tidal correction that is userfriendly, model-independent, and applies to many geophysical observables.