A project to recalibrate and combine spectroscopic surveys into one single catalog, as homogeneous as possible and calibrated on high-resolution studies. The Gaia catalogue helps us into combining the surveys together. We will keep the catalog updated with new survey releases and will gradually increase the number of stellar parameters. The method was tested  on radial velocities (Tsantaki et al. 2022) and we are now working on Teff, logg, and [Fe/H] for about 5 millions of stars. We are also testing the possibility of using the SoS catalog as a training set, to extract parameters from photometric surveys with machine learning (Turchi et al. 2024). 

We are working on the accurate derivation of Teff, logg, and [Fe/H] for about 15 million stars