Towards super-resolution via iterative multi-exposure coaddition

Abstract

In this article, we provide an alternative upsampling and point-spread function (PSF) deconvolution method for iterative multi-exposure coaddition. In contrast to previous works, the new method has a ratio-correction term, which allows the iterations to converge more rapidly to an accurate representation of the underlying image than methods with difference-correction terms. By employing this method, one can coadd undersampled multi-exposures to a super-resolution and obtain a higher peak signal-to-noise ratio. A set of simulations shows that there are many advantages of the new method, e.g. in the signal-to-noise ratio, average deviation of all source fluxes, super-resolution, and source distortion ratio, which are friendly to astronomical photometry and morphology and benefit faint source detection and shear measurement of weak gravitational lensing. The method provides an improvement in fidelity over the previous ones tested in this work.