The CDDIS provides an archive of GNSS data in support of the International GNSS Service (IGS, www.igs.org
). We have data in daily files (30 second sampling) going back to 1991, hourly files (30 second sampling), and high-rate files (1 second sampling). The daily data are typically delivered to the CDDIS within 1-6 hours after the end of the UTC day; the hourly data within 5 to 20 minutes after the start of the hour.
The operational archive of GNSS data consists of the U.S. GPS (Global Positioning System) and Russian GLONASS (GLObal NAvigation Satellite System) systems. In support of the IGS Multi-GNSS Experiment (MGEX), the CDDIS provides access to other GNSS such as Galileo, Japan’s QZSS (Quasi-Zenith Satellite System), China’s Beidou, and the Indian Regional Navigation Satellite System (IRNSS) systems.