Imperial College London

QSAS: Science Analysis Software for Space Plasmas

The QSAS project has moved to Sourceforge, and these pages are for access to archived versions and documentation only.

Downloads and support are now only available on Sourceforge:

Maintained Web pages are at

QSAS is a software package which provides a flexible, extendable environment for the selection, manipulation, and display of space physics data. QSAS is written in C/C++ and is compiled using the gnu compiler set, and makes use of several elements of third-party software, including Qt (, cdf ( and PLplot (

Currently available for Linux, Mac OSX  and Windows.

Finding out about QSAS

Other specifications can be found within the various items supplied with QSAS.

Obtaining QSAS

New downloads are now only available through sourceforge,
which will provide the appropriate version for your platform.

QSAS is provided free under GPL public licence, see licence file.

Linux download is a source distribution which builds itself using a build script (QSAS_3_2/bin/build). Edit the script to give the location of the QSAS distribution after download and the target directory for installing QSAS into, along with QT, and CDF installations on your platform, then type './build qsas' in the bin directory of the distribution:

Mac OSX download is ready to use and need only be unpacked and placed in /Applications.

Launch QSAS on the Mac by double clicking on the QSAS icon /Applications/QSAS_3_2/QSAS.

downloadis ready to use.

After unzipping, a QSAS32 folder will be created. If you place the QSAS32 directory inside C:\Program Files\QSAS, i.e., so that you have C:\Program Files\QSAS\QSAS32, it is ready to use.

Start QSAS by double-clicking QSAS.bat. You can also make shortcuts to this launcher.

If you install QSAS somewhere else, edit the first line of the QSAS.bat script to point to your installation directory. If QSAS launches but instantly dies, try to run this script from within a CMD console to inspect any error messages which may be output. Usually the problem is in the PATH specification, related to the installation location.

On platforms where it does not run out of the box, it is possible to build from source. In which case it will also be necessary to install msys2 (part of the MinGW package) and NASA's CDF libraries, available from:,
See the instructions in QSAS32/docs for more details. The msys2 installation will fetch and install both mingw and Qt5 for you, which are the remaining items necessary to build QSAS.


Older Versions of QSAS 3_1  are available and can be used for converting savesets.

Older Versions of QSAS 2_4  are available and can be used for converting savesets.

Older Versions of QSAS 2_3  are available, but are no longer supported.

Sample Data Files

The QSAS distribution contains some example data from Cluster Summary parameters as well as a sample session.

As well as Cluster Exchange Format (.cef) and NASA Common Data Format (.cdf) files, QSAS is able to read many ascii data files in either tabular or delimited syntax. These ascii files will need headers (either as detached (.qfh) headers or pasted onto the front of the data file itself. To help with the construction of suitable headers, some samples for different data sets are included with the distribution and are also available below, and collectively as a gzipped tar file.

With a few data records
Header only
NASA Omni High Resolution files with syntax omni_hr_format.txt omni_hr.qft omni_hr.qfh
Cluster vector and scalar variable examples in tabular (.qft) syntax CL_SP_FGM_20020328_V01.qft

Cluster vector and scalar variable examples in Cluster Exchange (.cef )syntax CL_SP_FGM_20020328_V01.cef

Cluster vector and scalar variable examples in delimited (.qfd) syntax CL_SP_FGM_20020328_V01.qfd

Cassini data in Cluster Exchange (.cef) syntax

Time Interval as a non-record varying variable (with tabular .qft extension)

Event List (list of time intervals) in delimited format
Event List as XML VOTable file


Plug-in Libraries

Plug-ins written by the QSAS team are distributed with the QSAS tar files, and install automatically at QSAS installation.
Many of the plugins provided by Stein Haaland are also distributed with QSAS precompiled.

Other QSAS plug-ins are also available from Stein Haaland.

Acknowledging QSAS in Publications

The preferred wording for acknowledging use of QSAS in publications is "Data analysis was done with the QSAS science analysis system provided by the United Kingdom Cluster Science Centre (Imperial College London and Queen Mary, University of London) supported by The Science and Technology Facilities Council (STFC)" or similar wording as appropriate.


This software was created by the CSC Team at IC. The team members have included, in alphabetical order, Tony Allen, Stuart Bale, Janet Barnes, Nora Bounaira, David Burgess, Gareth Chisham, Markus Fraenz, Anthony Hare, James Meakin, Alban Rochel, Steve Schwartz and Abdeslam Serroukh. Current team members are shown with an email address.

QSAS is developed as part of the Cluster Science Centre within the UK and funded by the Science and Technology Facilities Council (STFC). The software is provided as is under the GPL public licence, though QM and IC retain the copyright. No liability is accepted for any damage resulting from the installation or use of this software, and no guarantee of its suitability is implied for any use other than the scientific visualisation and manipulation of Cluster science data. Copyright.

Last up-dated 04 September 2019

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