Theoretical APS calculated for three of the 30 tomographic bins linearly spaced in frequency, whose average redshifts are , , and . The BAO wiggles appear at higher multipoles as the redshift increases. The dashed black line shows the white noise amplitude. The expected contribution from foreground residuals at the highest z-bin (; the one with the highest amplitude of foreground residual) is represented by the gray line. The dotted lines show the effect introduced by the instrumental beam with θ_FWHM = 40′.