Saved in:
Bibliographic Details
Main Author: Cao, Kaili
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.16110
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914232368365568
author Cao, Kaili
author_facet Cao, Kaili
contents Image regridding and coaddition have a wide range of applications in astronomical observations. {\sc Imcom}, an algorithm that provides control over point spread function (PSF) and noise in coadded images, has been found to meet the stringent requirements of weak gravitational lensing cosmology with the forthcoming Nancy Grace Roman Space Telescope. In this work, I introduce a new algorithm, Fast {\sc Imcom}, which outperforms traditional {\sc Imcom} in terms of both efficiency and quality. After explaining the underlying philosophy and mathematical formalism, I conduct systematic comparisons between {\sc Imcom} and Fast {\sc Imcom} in terms of PSF reconstruction in 1D. While a 2D implementation is beyond the scope of this paper, I demonstrate how to generalize Fast {\sc Imcom} to 2D and discuss practical issues involved. This new algorithm has the potential of reducing both the computational costs and storage requirements (current estimates are $\sim 100\,{\rm M}$ core-hours and $\sim 1.5 \,{\rm PB}$, respectively) of the Roman High Latitude Imaging Survey (HLIS) by an order of magnitude. Meanwhile, it provides implications for the dithering patterns of Roman surveys (extrapolated from 1D to 2D). I also address potential applications of Fast {\sc Imcom} beyond the Roman HLIS, with focus on other weak lensing programs and Roman time domain surveys; the actual range of use cases is likely beyond what is discussed here.
format Preprint
id arxiv_https___arxiv_org_abs_2510_16110
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Linear Image Regridding and Coaddition with Oversampled Point Spread Functions: Lessons from 1D
Cao, Kaili
Instrumentation and Methods for Astrophysics
Cosmology and Nongalactic Astrophysics
Image regridding and coaddition have a wide range of applications in astronomical observations. {\sc Imcom}, an algorithm that provides control over point spread function (PSF) and noise in coadded images, has been found to meet the stringent requirements of weak gravitational lensing cosmology with the forthcoming Nancy Grace Roman Space Telescope. In this work, I introduce a new algorithm, Fast {\sc Imcom}, which outperforms traditional {\sc Imcom} in terms of both efficiency and quality. After explaining the underlying philosophy and mathematical formalism, I conduct systematic comparisons between {\sc Imcom} and Fast {\sc Imcom} in terms of PSF reconstruction in 1D. While a 2D implementation is beyond the scope of this paper, I demonstrate how to generalize Fast {\sc Imcom} to 2D and discuss practical issues involved. This new algorithm has the potential of reducing both the computational costs and storage requirements (current estimates are $\sim 100\,{\rm M}$ core-hours and $\sim 1.5 \,{\rm PB}$, respectively) of the Roman High Latitude Imaging Survey (HLIS) by an order of magnitude. Meanwhile, it provides implications for the dithering patterns of Roman surveys (extrapolated from 1D to 2D). I also address potential applications of Fast {\sc Imcom} beyond the Roman HLIS, with focus on other weak lensing programs and Roman time domain surveys; the actual range of use cases is likely beyond what is discussed here.
title Linear Image Regridding and Coaddition with Oversampled Point Spread Functions: Lessons from 1D
topic Instrumentation and Methods for Astrophysics
Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2510.16110