Foreseen constraints (1σ contours) for a set of five ΛCDM parameters, plus three galaxy bias parameters (out of a total of 20) for a DESI-like survey. We assume 20 tomographic Gaussian bins of size σ_z = 0.01. The blue lines are the constraints for angular galaxy clustering alone D_g, the orange lines are for the ARF alone D_z, and the green line is a joint analysis of both fields D_g,  z. The figures above the 1-D PDFs give the marginalised 1σ uncertainty of the parameter for each data vector. We show here only three galaxy bias parameters, even if we marginalised upon the 20 bias parameters.