Why Geb?

  • PPP: client for autonomous positioning and precise coordinate monitoring using zero-difference GNSS observations supported with external precise products (satellite orbits, clock corrections, hardware biases, troposphere and ionosphere precise models)
  • RTK: client for relative positioning and precise coordinate monitoring using double-difference GNSS observations at short (up to 15 km) baselines.
  • G-Nut/Geb is a tool for precise positioning based on multi-GNSS data stemming from static or kinematic receivers.


  • post-processing coordinate estimates (reference frames)
  • long-term coordinate monitoring (geodynamical applications)
  • real-time kinematics (RTK)
  • precise point positioning (PPP)
  • precise point positioning with ambiguity resolution (PPP-AR)
  • precise point positioning with fast ambiguity resolution



  • Strategy: autonomous or relative positioning
  • Estimators: Kalman filter, backward smoother
  • Modelling: compliant with the IERS 2010 standards
  • Observations: multi-frequency pseudoranges and carrier phases
  • Configuration: flexible command-line and XML-file settings
  • Multi-GNSS: GPS, GLONASS, Galileo, BeiDou
  • Integer ambiguity resolution: GPS, Galileo


  • Real-time: forward filter using data streams
  • Post-processing: filter+smoother using high-accuracy products
  • Static/kinematic mode: reference stations / moving platforms
  • Ambiguity resolution: PPP applying phase biases (PPP-AR)
  • Fast ambiguity resolution: PPP applying phase biases and iono/tropo precise models (PPP-RTK)
  • Differential positioning: baseline limited up to 15 km (RTK)


  • Bias SINEX files (code and phase biases)
  • SINEX files (station meta data)
  • ATX files (antenna phase center offsets and variations)
  • BLQ files (ocean-tide loading station coefficients)
  • SP3 files (precise orbits) and RINEXC files (satellite clocks)
  • ERP files (Earth orientation parameters)
  • RINEX 2/3/4 files (observation and navigation data)
  • RTCM 3 streams (real-time data/products via NTRIP)
  • SSRZ streams/files (complete set of precise corrections for PPP-RTK)


  • LOG file for common logging
  • PPP file for processing logging (individual stations)
  • FLT for results from forward filter (individual stations)
  • SMT for results from backward smoother (individual stations)
  • SINEX file for estimated coordinates (solution product)


Latest releases

  • Geb Trial: 3
  • Geb Pro: 3
  • Geb Real-Time: 3

Software version

  • 30-day trial version (Trial)
  • Full functionality (Pro)
  • Full & Real-Time (Real-Time)


  • Linux (default distribution)
  • OSX (extra fee)
  • Windows (extra fee)

Pre-compiled binaries only.


Geb Trial

30-day trial version with a full functionality of G-Nut/Geb Pro & RT (Real-Time)

no fee

Geb Pro

Commercial software for post-processing multi-GNSS PPP solution

from 3000 EUR

Geb Real-Time

Commercial software for post-processing and real-time processing

from 4500 EUR

The price is for a major release, for a consecutive update the price is reduced by 50%.
The price depends on number of stations.


Reference Monitor

An ELK-driven system designed for real-time monitoring of GNSS station coordinates and related auxiliary information. It consists of geographical views and time-series plots both supporting an interactive selection of data sources, parameter types, individual vs. combined views, setting of parameter ranges etc. Geographical plot animations and sortable numerical data tables then complete the system.



Basic usage and help instructions.


A detailed description of the software.

Individual support

Available on request. Contact us at

Support fee can be combined with a software fee.


Global Navigation Satellite Systems (GNSS) are widely used for positioning. An accuracy of achieved receiver coordinates depends on used equipment, external products, and processing software. Systematic errors influencing GNSS observations can be either eliminated or reduced by forming double-differences (i.e. RTK strategy), or they can be estimated or introduced by external products (i.e. PPP strategy). In the case of PPP, the initial convergence can be reduced with integer ambiguity resolution. However, initial ambiguities can be resolved as integers only if phase biases are employed from external products. Moreover, when precise ionospheric and tropospheric models are employed, the ambiguities can be resolved even faster. (read more)