As the era of high precision cosmology approaches, the empirically determined
power spectrum of the microwave background anisotropy, Cl, will provide a
crucial test for cosmological theories. We present a unified semi-analytic
framework for the study of the statistical properties of the Cl coefficients
computed from the results of balloon, ground based, and satellite experiments.
An illustrative application shows that commonly used approximations {\it bias}
the estimation of the baryon parameter Ωb at the 1% level even for a
satellite capturing as much as ∼70% of the sky.Comment: 4 pages, 3 figures. Also available at
http://www.tac.dk/~wandelt/downloads.htm