Fast estimation of polarized CMB power spectra

We present a fast method for estimating the cosmic microwave background polarization power spectra using unbiased estimates of heuristically weighted correlation functions. We introduce new estimators that preserve electric (<f>E</f>) and magnetic (<f>B</f>) separation where only a subset of angular scales is available on the spherical sky; their construction requires an additional integration of the correlation functions but at negligible computational cost. We illustrate our methods with application to a large-area survey with parameters similar to Planck, and the small-area Background Imaging of Cosmic Extragalactic Polarization experiment. In both cases we show that the errors on the recovered power spectra are close to theoretical expectations. [Copyright &y& Elsevier]