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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 For example, the IERS2010 conventions describe only one method for the outdated FES2004 model that does not apply directly to current models.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 ignores 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.

Meanwhile, the Gravity Recovery Object Oriented Programming System (GROOPS) is a highly developed and well accepted tool in the scientific community that allows the user to perform core geodetic tasks. The main applications of the software include gravity field recovery from satellite and terrestrial data, the processing of global navigation satellite system (GNSS) constellations and ground station networks and the precise orbit determination of low earth orbiting (LEO) satellites. In the course of the continuous further development of GROOPS we extended the software by satellite laser ranging (SLR) as an additional feature. By means of SLR it is possible to obtain distance measurements from LEO satellites with an accuracy in the mm and cm range. On this basis, we will be able to perform a validation of our own determined satellite orbits, which we publish regularly. Since, for the estimation of the very long-wave part of Earth’s gravity field, SLR to geodetic satellites is advantageous compared to GRACE/GRACE-FO, it is a common practice to combine individual solutions based on different observation techniques. However, when combining solutions estimated by different institutions inconsistencies may occur due to the different algorithms and models used in the actual available software. Through the usage of a consistent SLR processing chain with GROOPS, we are able to mitigate this performance degradation. In this work we will give an overview of the integration of the SLR processing and we will show the gravity field results of SLR and GRACE/GRACE-FO combination., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)