Flowchart of this work. Left panel: Analysis (in light yellow region), representing the process of using real survey data to measure the angular power spectrum. Right panel: Modelling (in light blue region), which consists of generating mock catalogues and computing the theoretical angular power spectrum. The measured C_ℓ, the theoretical prediction, and the covariance matrix (computed from 1000 mock catalogues) are then used to construct the final likelihood. The likelihood is subsequently used for Markov chain Monte Carlo (MCMC) parameter estimation. Note: the theoretical templates differ depending on whether the constraints are on the BAO parameters or the bias parameters.