THELI v2 is no longer supported as of February 2018, as the code base is very outdated and faces increasing installation difficulties. A complete rewrite, THELI v3, is available from https://github.com/schirmermischa/THELI. Despite still being a beta release, it offers numerous and vast improvements over v2, and has produced data for scientific publications since mid 2019. It is still undocumented, but users familiar with v2 will find it easy to switch to v3. If you are new to THELI, you should try v3 first, and revert to v2 only if necessary. If in doubt, contact me at schirmer[at]mpia.de.

THELI GUI (outdated)

Last update:Mar 23, 2018
Latest changes:ChangeLog

THELI is a powerful and easy-to-use package for astronomical image reduction, offering e.g.

  • Automated reduction of optical, NIR and MIR data
  • 90 pre-configured instruments
  • Parallelisation
  • Flexible background correction
  • Automatic distortion correction and creation of large mosaics
  • Highly flexible coaddition: e.g. locking onto proper motion targets, various projections, etc
  • Optimised weighting schemes and defect detection
  • Crosstalk and non-linearity correction
  • Atmospheric transparency correction
  • Absolute flux calibration
  • Extensive documentation and online help



Please cite the following two papers when publishing your scientific work based on THELI:

  • Schirmer M. 2013, ApJS, 209, 21: THELI GUI – Convenient reduction of optical, near- and mid-infrared imaging data
  • Erben, T., Schirmer, M., Dietrich, J. et al. 2005, AN, 326, 432: GaBoDS: The Garching-Bonn Deep Survey. IV. Methods for the image reduction of multi-chip cameras demonstrated on data from the ESO Wide-Field Imager