Super-resolution in map-making based on a physical instrument model and regularized inversion. Application to SPIRE/Herschel

TL;DR

This paper presents a physically-based super-resolution method for map-making from Herschel SPIRE data, significantly enhancing spatial resolution by reconstructing higher spatial frequencies than standard techniques.

Contribution

It introduces a regularized inversion approach based on an accurate instrument model, enabling super-resolution in astronomical map reconstruction.

Findings

Restores spatial frequencies four times higher than coaddition.

Achieves significant resolution improvements on real Herschel data.

Demonstrates effectiveness with simulated and real datasets.

Abstract

We investigate super-resolution methods for image reconstruction from data provided by a family of scanning instruments like the Herschel observatory. To do this, we constructed a model of the instrument that faithfully reflects the physical reality, accurately taking the acquisition process into account to explain the data in a reliable manner. The inversion, ie the image reconstruction process, is based on a linear approach resulting from a quadratic regularized criterion and numerical optimization tools. The application concerns the reconstruction of maps for the SPIRE instrument of the Herschel observatory. The numerical evaluation uses simulated and real data to compare the standard tool (coaddition) and the proposed method. The inversion approach is capable to restore spatial frequencies over a bandwidth four times that possible with coaddition and thus to correctly show details invisible on standard maps. The approach is also applied to real data with significant improvement in spatial resolution.