Fast map-based simulations of systematics in CMB surveys including effects of the scanning strategy

TL;DR

This paper introduces rapid map-based simulation methods for CMB survey systematics, significantly accelerating the process while maintaining high accuracy, enabling efficient modeling of complex systematic effects across large detector arrays.

Contribution

The paper presents novel map-based simulation techniques that drastically improve speed and scalability in modeling CMB systematic effects, including the scanning strategy.

Findings

Achieved 3-4 orders of magnitude speedup over full TOD simulations.

Maintained sub-percent accuracy in capturing systematic features.

Successfully applied methods to simulate thousands of detectors in modern CMB experiments.

Abstract

We present approaches to quickly simulate systematics affecting CMB observations, including the effects of the scanning strategy. Using summary properties of the scan we capture features of full time ordered data (TOD) simulations, allowing maps and power spectra to be generated at much improved speed for a number of systematics - the cases we present experienced speed ups of 3-4 orders of magnitude when implementing the map-based approaches. We demonstrate the effectiveness of the approaches at capturing the salient features of the scan by directly comparing to full TOD simulations - seeing agreement at sub-percent levels of accuracy. We simulate the effects of differential gain, pointing, and ellipticity to show the effectiveness of the approaches, but note that one could extend these techniques to other systematics. We finally show how to apply these fast map-based simulations of systematic effects to a full focal plane showing their ability to incorporate thousands of detectors as seen in modern CMB experiments.