  We estimate the sensitivity of future galaxy surveys to cosmological
parameters, using the redshift dependent angular power spectra of galaxy number
counts, $C_\ell(z_1,z_2)$, calculated with all relativistic corrections at
first order in perturbation theory. We pay special attention to the redshift
dependence of the non-linearity scale and present Fisher matrix forecasts for
Euclid-like and DES-like galaxy surveys. We compare the standard $P(k)$
analysis with the new $C_\ell(z_1,z_2)$ method. We show that for surveys with
photometric redshifts the new analysis performs significantly better than the
$P(k)$ analysis. For spectroscopic redshifts, however, the large number of
redshift bins which would be needed to fully profit from the redshift
information, is severely limited by shot noise. We also identify surveys which
can measure the lensing contribution and we study the monopole, $C_0(z_1,z_2)$.
