Quantifying Roman WFI Dark Images with the Wavelet Scattering Transform

TL;DR

This paper demonstrates how the wavelet scattering transform can analyze Roman Space Telescope dark images to identify instrumental patterns, aiding in detector calibration and improving weak lensing measurements.

Contribution

It introduces the application of the wavelet scattering transform to space telescope images for characterizing instrumental noise and patterns, enhancing data analysis techniques.

Findings

Scattering statistics effectively distinguish instrumental patterns from noise.

The method provides interpretable features for analyzing detector images.

Results support improved calibration for weak lensing science.

Abstract

The Nancy Grace Roman Space Telescope will survey a large area of the sky at near-infrared wavelengths with its Wide Field Instrument (WFI). The performance of the 18 WFI H4RG-10 detectors will need to be well-characterized and regularly monitored in order for Roman to meet its science objectives. Weak lensing science goals are particularly sensitive to instrumental distortions and patterns that might masquerade as astronomical signals. We apply the wavelet scattering transform in order to analyze localized signals in Roman WFI images that have been taken as part of a dark image test suite. The scattering transform quantifies shapes and clustering information by reducing images into non-linear combinations of wavelet modes on multiple size scales. We show that these interpretable scattering statistics can separate rare correlated patterns from typical noise signals, and we discuss the results in context of power spectrum analyses and other computer vision methods.