# 7.3 Comparison to models

Author(s): Céline Reylé, Annie Robin, Sékou Diakité

Comparisons with models have been performed to check the data for star density, median distribution of parameters as a function of position on the sky and of $G$ magnitude. The reference model is the GOG20 simulation which is also released with the Gaia EDR3 set of catalogues. The tested parameters are parallaxes, $G_{\mathrm{BP}}-G_{\mathrm{RP}}$ colours, proper motions and radial velocities.

In order to have good statistics in each pixel of the sky maps, the comparisons are done using healpix of order 4, corresponding to 3072 pixels per sky map.