Employ high-resolution spectra from X-shooter library to investigate how the Gaia spectra will look like.

Investigate GSP-Phot performance on X-shooter spectra.

Gaia RVS spectra and corresponding segments of x-shooter spectra look very similar. Ca-Triplet lines are easily identified and other prominent lines are also in obvious correspondence.

x-shooter spectra contain telluric bands around 760nm and 950nm. In fact, BP/RP shows prominent dips there, which are NOT reflected by space-based instrument models. That must be a problem when modelling those spectra with GSP-Phot.