Illustration of the galaxy survey data model used in this study. (Upper and middle rows) Slices through a realisation of the dark matter overdensity fields in real space (top) and redshift space (middle). The fields are evolved in time using N-body simulations, starting from a grid of Gaussian initial dark matter density fluctuations with power spectrum θ_gt, up to the redshift indicated above the corresponding panels. (Lower row) Observed galaxy number count fields for the three galaxy populations, each defined on a grid of 512³ cells. Light-cone effects are accounted for by using one effective redshift per galaxy population. Each slice passes through the observer located at the (0, 0, 0) corner of the box.