Can GLONASS be used to correct GNSS

Product name

APOS - Austrian Positioning Service

Short name


Product group

3D positioning

Product definition

APOS is the GNSS satellite positioning service of the BEV, which uses GNSS signals (GPS, GLONASS and GALILEO), processes them centrally and provides parameters derived from them to improve the accuracy of satellite-based measurements. Each APOS reference station is coordinated to the centimeter and equipped with high-quality geodetic GNSS equipment. The service center provides raw station data for postprocessing applications (APOS-PP) for the area covered by APOS, as well as individual correction parameters for satellite orbits, satellite clocks, ionosphere and troposphere in the form of a "virtual" Reference station (VRS) "calculated in real time (APOS Real Time). With the help of the VRS, short baselines and thus short measurement times on site result. The "Master Auxiliary Concept-MAC" is also supported for receiving and processing the GPS / GLONASS signals.

APOS Real Time provides the data in the field via mobile internet (NTRIP via packet-switched data transmission) for VRS and MAC-capable measuring devices, i.e. H. After the mobile internet connection to the APOS service center has been established, the proximity position is automatically transmitted by the recipient in order to be able to calculate the individual VRS (or MAC network information) centrally.

Two accuracy classes are offered under APOS Real Time:

  • APOS-RTK with cm accuracy for high-precision applications with multi-frequency phase measuring devices.
    Additional service: When using APOS-RTK (RTCM 3.1, RTCM 3.2 MSM-Multi Signal Message), a uniform Austria-wide transformation into the state-Austrian geodetic reference system MGI (for GIS applications) is made possible by means of GIS-Grid glicht.

  • APOS-DGPS with submeter accuracy for GIS and navigation applications using phase-smoothing code measuring devices.

Due to the integration of many GNSS reference stations from neighboring countries, APOS is the positioning service for Austria, which offers homogeneous 3D coordinates throughout the European terrestrial reference system ETRS89.

Suitability / use

  • Basic, cadastral and scientific surveys
  • Agriculture and Forestry
    From February 1st, 2021, the Federal Office for Metrology and Surveying (BEV) in cooperation with the Federal Ministry for Agriculture, Regions and Tourism (BMLRT) will provide the RTK correction signal "APOS" for agricultural and forestry use Available free of charge. You can find all the information here.
  • Construction and engineering surveying
  • Measurement recordings with aircraft
  • geological and geophysical point surveys
  • GIS surveys
  • Staking out and routing
  • Machine controls

Data type

3-dimensional coordinates in the ETRS89 and MGI systems

Last change