Star Life

THELI – tool for the automated reduction of astronomical images

THELI is a tool for the automated reduction of astronomical images. Its software modules cover all necessary tasks from raw images of single- and multi-chip CCD cameras up to astrometrically and photometrically calibrated co-added images. The main focus is on observations in optical wavelengths.

It’s available as a GUI and a set of command-line based scripts. These are developed independently.

The THELI GUI is a very flexible and interactive tool, offering a broad range of routines for optical, near- and mid-infrared images. Many different instruments from observatories world-wide are pre-configured.

The scripts are suitable for survey work, i.e. you have a very large number of different pointings taken with the same optical instrument. Contrary to the GUI, it can be run in batch mode, and also on a Linux cluster.

Features of the GUI:

  • 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.
  • Optimized weighting schemes and defect detection.
  • Crosstalk and non-linearity correction.
  • Atmospheric transparency correction.
  • Absolute flux calibration.
  • Extensive documentation and online help.

Website: (GUI)
Support: FAQ
Developer: Mischa Schirmer (GUI), Thomas Erben (CLI)
License: GNU General Public License v2.0 or any later version (GUI + CLI)

THELI is written in C++. Learn C++ with our recommended free books and free tutorials.

Return to Astronomical Data Analysis

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