Lensing reconstruction in the third generation of ground-based small aperture cosmic microwave background telescope

Abstract

We introduce the lensing reconstruction algorithm and the corresponding pipeline construction of the third generation of the ground-based small aperture cosmic microwave background (CMB) experiment. We assume a characteristic and simplified telescope model, namely 3600 degree square sky coverage, media noise level ($\sim$10 $\mu$K.arcmin) and media angular resolution (beam size 10 arcmin). We adopt the technically mature quadratic estimator and study the reconstruction ability of the T-only, P-only, and the minimal-variance estimator. Using the framework of the quadratic estimators, we developed our lensing reconstruction pipeline. We find, at the 17 $\mu$K.arcmin noise level, the reconstruction noise of the P-only estimator is worse than that of the T-only estimator. When we upgrade into the 10 $\mu$K.arcmin noise level case, the results are reversed. Furthermore, when we combine the temperature and polarization modes together, the minimal-variance estimator can reach the signal-to-noise ratio of 17 with the 10 $\mu$K.arcmin noise setup.