André Offringa


The AOFlagger is a flagger framework that implements several methods to deal with radio-frequency interference or RFI.

I have spent a lot of time on this package, and I believe it is the best available flagger. If you use this package for scientific work, please acknowledge my work and cite the following paper that introduced the latest algorithm:

For the MWA, when using the AOFlagger inside the Cotter software, one can cite this paper instead:

Latest release

Click the following button to download the latest release:

Refer to the changelog for version 2.10 (list of older changelogs) and the installation instructions for more information.

AOFlagger 2.10 was released on 6 February 2018.

Manual pages

The official page of the AOFlagger is http://aoflagger.sourceforge.net/. The software package contains the flagger as a library (libaoflagger) that can be integrated into observatory pipelines by using the Application Programming Interface (API), along with several programs to execute the flagger on measurement sets, tweak it and visualize results.


  1. Introduction
  2. Installation instructions
  3. Scripted plotting: how aoflagger and aoqplot can be used to make quality plots from the command line or a script.
  4. Frequency-asked questions
  5. Programs:
    • aoflagger: executes a given flagging strategy on a full measurement set;
    • rfigui: for analyzing RFI, data and for strategy parameter tweaking;
    • aoqplot: for fast visualization of statistics, to assert the generic data quality;
    • other tools which are less frequently used tools.

See also the LOFAR cookbook for LOFAR-specific info about running the flagger.

Contact information

In case of questions, suggestions or feedback, please mail me. My e-mail address is <mylastname>@gmail.com, and my last name is offringa.


Thanks to all who provided data to me for testing, in special my PhD supervisor Ger de Bruyn. Also thanks to Andy Biggs and Ger van Diepen for several fixes and hints, and all others who have provided bug reports. The RFI tools make heavy use of Casacore, thus their authors have been instrumental in creating the flagger.

Project Admins:


Wiki: Introduction
Wiki: aoflagger
Wiki: bibtex_offringa_2012_morph_algorithm
Wiki: bibtex_offringa_2015_mwa_environment
Wiki: changelog-2.10.0
Wiki: changelog_list
Wiki: faq
Wiki: installation_instructions
Wiki: rfigui