User Guide to UVIT Data Reduction

TL;DR

Provides a practical guide for reducing UVIT data with CCDLAB, addressing common workflow challenges and offering targeted troubleshooting for WCS solutions and VIS drift tracking. Builds on the 2021Postma UVIT reduction guidance by detailing step-by-step procedures, from Level 1 data digestion and blind registration to source-based drift correction and image merging. Key contributions include Gaia DR3-based WCS solving via AstraCarta, de-rotation, and finalization of merged datasets, plus manual VIS tracking when automated methods fail. The guide is complemented by video tutorials and explicit caveats (hot pixels, artifact mitigation) to improve accuracy and efficiency in UVIT data analysis.

Abstract

This document provides a user guide for reducing UVIT data using CCDLAB. While CCDLAB offers a straightforward data reduction work-flow, users may encounter certain challenges that require additional guidance. This guide provides instructions by addressing common issues related to key processing steps, including WCS solutions and VIS drift tracking.

Figures (8)

• Figure 1: Level 1 FITS digestion.
• Figure 2: Ignore hot pixel option.
• Figure 3: Example of a hot pixel in Image (Top) and hot pixel ignored image (Bottom).
• Figure 4: CCD World coordinate solver.
• Figure 5: CCD World coordinate solver: Stopping criteria.