Shot noise estimation over 100 realisations. Blue dots, black squares and red triangles represent the angular power spectrum of the half-sum (HS) maps, which contain the contribution of both signal and noise, in our three redshift bins (panels from left to right). The purple pentagons show instead the angular power spectrum of the half-difference (HD) maps, which provides a direct estimation of the shot noise, with their average (purple dashed line) and their standard deviation (purple shaded band) in agreement with the theoretical Poissonian value (cyan solid line).