Global Navigation Satellite System (GNSS) Final Cumulative Combined Station Positions/Velocities Product from NASA CDDIS

This derived product set consists of Global Navigation Satellite System Final Combined Station Positions/Velocities Product available from the Crustal Dynamics Data Information System (CDDIS). GNSS provide autonomous geo-spatial positioning with global coverage. GNSS data sets from ground receivers at the CDDIS consist primarily of the data from the U.S. Global Positioning System (GPS) and the Russian GLObal NAvigation Satellite System (GLONASS). Since 2011, the CDDIS GNSS archive includes data from other GNSS (Europe’s Galileo, China’s Beidou, Japan’s Quasi-Zenith Satellite System/QZSS, the Indian Regional Navigation Satellite System/IRNSS, and worldwide Satellite Based Augmentation Systems/SBASs), which are similar to the U.S. GPS in terms of the satellite constellation, orbits, and signal structure. Analysis Centers (ACs) of the International GNSS Service (IGS) retrieve GNSS data on regular schedules to produce precise orbits identifying the position and velocity of the GNSS satellites as well as precise station positions and velocities for the network of GNSS receivers. The IGS Reference Frame Coordinator uses these individual AC solutions to generate the official IGS station position/velocity product. The cumulative final product can contain several position and velocities sets per station over specific time periods to model discontinuities. The final products are considered the most consistent and highest quality IGS solutions and consists of daily and weekly station position and velocity files in SINEX format, generated on a daily/weekly basis by combining solutions from individual IGS ACs, approximately 11-17 days after the end of the solution week.