Data and Products


The GNSS data consist of the receiver’s observation data, the broadcast orbit information of the tracked satellites, and supporting data, such as meteorological parameters, collected from co-located instruments. Currently, the IGS network consists of over 500 globally distributed stations, equipped with geodetic-quality receivers that track the GPS satellite constellation; a subset of this network are capable of tracking both GPS and GLONASS satellite signals. Furthermore, some stations are upgraded with multi-GNSS receivers capable of obtaining signals from GPS, GLONASS, Galileo and other GNSS (BeiDou, QZS, etc.). These data are available through the CDDIS portal.

Data from the global GNSS permanent receiver network support the IGS are organized in subdirectories by

  • Daily 30-second sampled GNSS tracking data: ~2.5 Mbytes/site/day (compressed)
  • High-rate 1-second sampled GNSS tracking data: ~20 Mbytes/site/day (compressed)

Daily GNSS tracking data: Receiver INdependent EXchange (RINEX) format (RINEX version 2/RINEX version 3), Unix-compressed, Hatanaka format


Products derived from GNSS data archived in the CDDIS are generated and submitted by the IGS analysis and associate analysis centers. IGS products support scientific research in:

  • Realization of the International Terrestrial Reference Frame (ITRF)
  • Monitoring deformation of the solid Earth
  • Monitoring Earth rotation
  • Monitoring variations in the hydrosphere (sea level, ice sheets, etc.)
  • Scientific satellite orbit determination
  • Monitoring the Earth’s ionosphere and troposphere
  • Time and frequency transfer

IGS operational products include precise GNSS satellite ephemerides, positions and velocities of stations in the global GNSS network, EOPs (polar motion and rates, length-of-day), and station and satellite clock solutions. Other products derived from the CDDIS GNSS data holdings include troposphere Zenith Path Delay (ZPD) estimates (both dry and wet components) and global ionosphere maps, in support of IGS Working Groups or Pilot Projects.

  • GNSS orbit, station position, and EOP products since June 1992
  • Troposphere Zenith Path Delay (ZPD) products since January 1997
  • Ionosphere Total Electron Content (TEC) products since June 1998
  • Weekly and daily GNSS orbits, station position, and EOP files: ~1.5 Gbytes/week (compressed)
  • Daily troposphere files: ~3 Mbytes/day (compressed)
  • Daily ionosphere files: ~5 Mbytes/day (compressed)

Data formats