Planck 2018 results. II. Low Frequency Instrument data processing

TL;DR

This paper details the final data-processing pipeline for the Planck Low Frequency Instrument, highlighting improvements in calibration and instrumental corrections, and presents the final sky maps and parameter estimates from the 2018 data release.

Contribution

It provides a comprehensive description of the improved data-processing pipeline and the resulting high-quality sky maps and parameter estimates for the Planck LFI.

Findings

Finalized LFI sky maps at 30, 44, 70 GHz in temperature and polarization

Refined estimates of the Solar dipole

Assessment of instrumental parameters and pipeline consistency

Abstract

We present a final description of the data-processing pipeline for the Planck, Low Frequency Instrument (LFI), implemented for the 2018 data release. Several improvements have been made with respect to the previous release, especially in the calibration process and in the correction of instrumental features such as the effects of nonlinearity in the response of the analogue-to-digital converters. We provide a brief pedagogical introduction to the complete pipeline, as well as a detailed description of the important changes implemented. Self-consistency of the pipeline is demonstrated using dedicated simulations and null tests. We present the final version of the LFI full sky maps at 30, 44, and 70 GHz, both in temperature and polarization, together with a refined estimate of the Solar dipole and a final assessment of the main LFI instrumental parameters.