The Crustal Dynamics Data Information System (CDDIS) was initially developed to provide a central data bank for NASA's Crustal Dynamics Project (CDP). The system continues to support the space geodesy and geodynamics community through NASA's Space Geodesy Program as well as NASA's Earth Science Enterprise. The CDDIS was established in 1982 as a dedicated data bank to archive and distribute space geodesy related data sets. Today, the CDDIS archives and distributes mainly Global Navigation Satellite Systems (GNSS, currently Global Positioning System GPS and GLObal NAvigation Satellite System GLONASS), laser ranging (both to artificial satellites, SLR, and lunar, LLR), Very Long Baseline Interferometry (VLBI), and Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS) data for an ever increasing user community of geophysists.

The CDDIS is operational on a dedicated computer located at the Goddard Space Flight Center in Greenbelt, MD. All NASA investigators, staff, and cooperating institutions have access to the CDDIS computer facility through Internet.

The CDDIS has served as a global data center for the International GPS Service (IGS) since 1992. The CDDIS supports the International Laser Ranging Service (ILRS), the International VLBI Service for Geodesy and Astrometry (IVS), the DORIS Pilot Experiment, a precursor to the International DORIS Service (IDS), and the International Earth Rotation Service (IERS) as a global data center.

To learn more about these space geodetic techniques and their respective CDDIS data holdings, click on the images below.

GNSS (GPS and GLONASS)	SLR	VLBI	DORIS