Article Index

"G-Nut/Tefnut" is the end-user application designed to estimate tropospheric path delays in various processing modes. Below applications are implemented using the G-Nut core library developed at the Geodetic Obsevatory Pecny. A comparison of supported capabilities is available in the feature matrix. All applications are released under the GNU General Public Licence.
Figure shows an example of Tefnut's real-time troposphere monitoring in real-time mode using IGS RTCM clock and orbit corrections.

Example Tefnut real-time troposphere monitoring in a real-time mode

  • Tefnut-PP is free open source lite application aimed for the post-processing mode.
  • Tefnut-RT is free open source lite application aimed for the real-time processing mode.

DOWNLOAD - the software download.
INSTALLATION - instruction for the installation.

  • Tefnut is non-free application providing enhanced capabilities while including all processing modes (RT, NRT and PP), improved models and more flexible use.
    The release is under preparation.

SUPPORT - the current lite version is provided as a beta release and still undergoes final consolidations of the core library. The software is provided "as is" and without warranty of any kind. The support is given on a best-effort basis only. However, if you find G-Nut/Tefnut application(s) useful for your work, consider supporting its further development by ordering the enhanced version and we will try to give you a priority in the support.
Other related questions could be sent to This email address is being protected from spambots. You need JavaScript enabled to view it. (J.Dousa/P.Vaclavovic).


  • Dousa J, Vaclavovic P (2014) Real-time zenith tropospheric delays in support of numerical weather prediction applications. Advances in Space Research (2014), Vol 53, No 9, pp 1347-1358,  doi:10.1016/j.asr.2014.02.021, PDF.
  • Dousa J and Vaclavovic P (2013), Real-time ZTD estimates base on Precise Point Positioning and IGS real-time orbit and clock products, In: 4th International Colloquium Scientific and Fundamental Aspects of the Galileo Programme, 4-6 December 2013, Prague, Czech Republic. PDF.
  • Vaclavovic P, Dousa J, Gyori G (2013), G-Nut software library - state of development and first results, Acta Geodynamica at Geomaterialia, pp 431-436, Vol. 10, No. 4 (172), doi:10.13168/AGG.2013.0042. PDF (or, alternatively, here).

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