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QDOAS Technical support

QDOAS is open source and distributed free of charge. This software is not a commercial product and is not funded at all. Consequently, developers provide support within the limit of their available time. QDOAS was developed and tested first for BIRA-IASB applications. Because of the large number of possible configurations, it is possible that some bugs remain for configurations with rarely used combinations of options. If you believe you have found a bug, please contact the authors (see below). In order to help us investigate the problem, please mention the version of QDOAS you are using, and, if possible, provide us with an example configuration, completed with all auxiliary data (wavelength calibration, reference spectra, cross sections,...) and some sample files in order us to test.

The user manual is out of date for the most recent developments reserved to advanced users. But it provides some help to start an application and most options are detailed. It also gives a short description of the algorithms used, but we strongly recommend that beginners who have never worked with DOAS before read dedicated literature (for example: Differential Optical Absorption Spectroscopy. Principles and Applications, Ulrich Platt and Jochen Stutz, 2008).


Please refer to the user manual.

Known issues

The following issues are related to the the user interface.

  • Some error messages are incomplete or missing usually in case of wrong path or input file not found
  • Go up to previous spectra in the file using buttons of the tool bar blocks if one record doesn't reply to selection conditions; select the record number instead;
  • Overlay of spectra works only for data with the same number of points, not for partial spectra or xs


  • Read dedicated literature if you are a DOAS beginner (see first paragraph of this page) !!!
  • Always save your application before running analysis;
  • Check the list of last changes and fixed bugs;

Contact authors

QDOAS is developed at BIRA-IASB. For further information, technical support, bug reports, suggestions, or any other comments and questions, you may contact authors (qdoas AT

Last update on 13 Dec 2023