G-Nut/Anubis application

G-Nut/Anubis is a command-line tool for a quality check of modern data from all available GNSS constellations providing full quantitative and qualitative control with support of GNSS navigation messages:

  • observation statistics (counts of observations, signals, bands, satellites of GPS, GLONASS, Galileo, BeiDou, SBAS, QZSS, IRNSS)
  • standard point positioning (if data and navigation messages provided for GPS, GLONASS, Galileo and BeiDou)
  • pre-processing including clock-jumps and cycle-slip detection and other interruptions over all constellations, frequencies and signals
  • satellite elevations and azimuths (if supported with constellation-specific navigation messages)
  • elevation-specific histograms, satellite ascending/descending times for horizon and user elevation cut-off
  • pseudo-range multipath and noise
  • carrier-phase signal-to-noise ratio
  • data gaps and small data pieces
  • outputs in specific XTR and minimalistic standard XML formats
  • other useful lists and statistics (satellite navigation data availability, satellite healthy status etc.)

The application is implemented exploiting the G-Nut core library developed originally at Geodetic Observatory Pecny (Václavovic and Douša, 2016). Since January 2018, it has been further maintained and developed by the G-Nut Software s.r.o. company which is a spin-off of the RIGTC/GOP. G-Nut/Anubis (free) provides a free application for the RINEX file qualitative and quantitative monitoring. It is released under GNU GPL. The G-Nut Software s.r.o. provides additionally Anubis Extra and Anubis Real-Time (RT) advanced commercial versions.

Anubis GNSS QC skyplot

The software is provided "AS IS", without warranty of any kind and a support is given on a best-effort basis only. Questions could be sent to This email address is being protected from spambots. You need JavaScript enabled to view it. for free version, and to This email address is being protected from spambots. You need JavaScript enabled to view it. for commercial versions.

G-Nut/Anubis download (new: registration required)
GOP's Multi-GNSS BRDC files (new: doi:10.24414/c4ba-kf16)


  • Vaclavovic P, Dousa J (2016), G-Nut/Anubis - open-source tool for multi-GNSS data monitoring, In: IAG Symposia Series, Springer, Vol. 143, pp. 775-782, doi:10.1007/1345_2015_157, PDF.
  • Václavovic P., Douša J..: Development Towards Advanced GNSS Data Quality Monitoring, In: Družicové metody v geodézii a katastru, Sborník referátů. Brno, ECON publishing, s.r.o, pp 76-81, 2015 (in english PDF)
  • Vaclavovic P and Dousa J (2013), Anubis – a tool for quality check of multi-GNSS observation and navigation data In: 4th International Colloquium Scientific and Fundamental Aspects of the Galileo Programme, 4-6 December 2013, Prague, Czech Republic. PDF.
  • 2020-07-18 - Released Anubis 2.3 - RINEX 3.04 support incl. BeiDou 3, newly distributed here
  • 2018-08-01 - Released Anubis 2.2 - improved functionality including various handling of satellite health
  • 2017-11-29 - Released Anubis 2.1 - version with major updates for supporting EPOS
  • 2016-10-05 - Released Anubis 2.0 - teqc total summary, expt/have at elev cut-off, preliminary XML output and IRNSS & RINEX3.03, etc.
  • 2016-01-27 - Released Anubis 1.4 - SNR support, SP3 format, Windows support, kinematic and high-rate processing
  • 2015-01-28 - Released Anubis 1.3 - all-constellations/-bands/-signal pre-processing, advanced statistics, merged navigation messages etc.
  • 2014-08-13 - Released Anubis 1.2 - navigation messages for all GNSS constellations, GPS, GLONASS, Galileo, BeiDou standard positioning
  • 2014-04-29 - Released Anubis 1.1 - qualitative QC for GPS&GLO, bancroft positioning, boost-independent version, RINEX3.02 support
  • 2013-08-16 - Released Anubis 1.0 - multi-path detection for all constellations, signals and frequencies
  • 2013-03-10 - Released Anubis 0.9 - beta version