WP8 – Systematic Uncertainties



This WP covers the analysis of systematic effects affecting the LFI maps produced in the new pipeline developed in this project.

Description of work

Our new pipeline will improve the quality and self-consistency of the Planck/LFI polarization maps, with minimal contamination from instrumental and astrophysical effects. However, deviations from the ideal map reconstruction will always be present at some level, due to a combination of residual foreground radiation and systematic effects. In the proposed optimisation process, it will be crucial to understand the origin of remaining imperfections, identify their source, and control the convergence of the iteration process. Building on our 25-years-experience of design, development, testing, flight operation and data analysis of the Planck/LFI instrument, our group at Milano University will support the interpretation of residual instrumental effects in the LFI map produced by the pipeline.

The work will be split in the following tasks:

  • Methodical inspection of different generations of maps produced by the pipeline, for different versions and at increasing iteration levels
  • Develop and implement an optimal scheme for null-test analysis to highlight residual anomalies in the data
  • Interpretation of the source of systematic effects in terms single instrumental features (such as stray light from far sidelobes, bandpass effects, ADC non-linearity, spikes in time domain, thermal effects, etc.)
  • Run simulations, where necessary, to confirm the above interpretation
  • Compare Planck/LFI maps with external data, in particular with WMAP maps and Planck-HFI maps