Short Name:

Ground-Based Global Navigation Satellite System Differential Code Bias Product from NASA CDDIS

This dataset consists of differential code biases (DCBs) from a network of ground-based Global Navigation Satellite System (GNSS) station and available from the NASA 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. DCBs are the systematic errors, or biases, between two GNSS code observations at the same or different frequencies. DCBs are required for code-based positioning of GNSS receivers, extracting ionosphere total electron content (TEC), and other applications. Proper knowledge of DCBs is crucial to many navigation applications but also non-navigation applications such as ionospheric analysis and time transfer. With all of the new signals offered by modernized and new GNSS constellations, analysts now require a comprehensive multi-GNSS DCB product. More information about these data is available on the CDDIS website at

Map of Earth