The Crustal Dynamics Data Information System (CDDIS) supports the space geodesy and geodynamics community through NASA's Space Geodesy Project as well as NASA's Earth Science Enterprise. The CDDIS was established in 1982 at NASA's Goddard Space Flight Center 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 geophysicists. The CDDIS serves as a global data center for the International GNSS Service (IGS) since 1992, the International Laser Ranging Service (ILRS), the International VLBI Service for Geodesy and Astrometry (IVS), International DORIS Service (IDS), and the International Earth Rotation and Reference Systems Service (IERS). General information, including summary reports, data set documentation, etc., are available through the CDDIS archive.

This dataset consists of ground-based Global Navigation Satellite System (GNSS) Observation Data (30-second sampling, daily 24 hour files) 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. The daily GNSS observation files (un-compacted) contain one day of GPS or multi-GNSS observation (30-second sampling) data in RINEX format from a global permanent network of ground-based receivers, one file per site. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/daily_30second_data.html.

This dataset consists of ground-based Global Navigation Satellite System (GNSS) Compact Observation Data (30-second sampling, daily, 24 hour files) 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. The daily GNSS observation files (compact) contain one day of GPS or multi-GNSS observation (30-second sampling) data in compact RINEX format from a global permanent network of ground-based receivers, one file per site. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/daily_30second_data.html.

This dataset consists of ground-based Global Navigation Satellite System (GNSS) Combined Broadcast Ephemeris Data (hourly files of all distinct navigation messages received in one day) 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. The hourly GNSS broadcast ephemeris files contain one day of mixed GNSS navigation (30-second sampling) data in RINEX format from a global permanent network of ground-based receivers, one file per site. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/hourly_30second_data.html.

This dataset consists of ground-based Satellite Laser Ranging observation data (full-rate, monthly files) from the NASA Crustal Dynamics Data Information System (CDDIS). SLR provides unambiguous range measurements to mm precision that can be aggregated over the global network to provide very accurate satellite orbits, time histories of station position and motion, and many other geophysical parameters. SLR operates in the optical region and is the only space geodetic technique that measures unambiguous range directly. Analysis of SLR data contributes to the terrestrial reference frame, modeling of the spatial and temporal variations of the Earth's gravitational field, and monitoring of millimeter-level variations in the location of the center of mass of the total Earth system (solid Earth-atmosphere-oceans). In addition, SLR provides precise orbit determination for spaceborne radar altimeter missions. It provides a means for sub-nanosecond global time transfer, and a basis for special tests of the Theory of General Relativity. Analysis Centers (ACs) of the International Laser Ranging Service (ILRS) retrieve SLR data on regular schedules to produce precise station positions and velocities for stations in the ILRS network. The monthly SLR full-rate observation files contain data received in the month from a global network of stations ranging to satellites equipped with retroreflectors. Data are available in ILRS data format (older data sets) and/or the Consolidated Ranging Data (CRD) format. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/SLR/Full-rate_data.html.

This dataset consists of ground-based Global Navigation Satellite System (GNSS) Satellite-Based Augmentation System (SBAS) Broadcast Ephemeris Data (hourly files) 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 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. The hourly SBAS broadcast ephemeris files contain one day of SBAS broadcast navigation data in RINEX format from a global permanent network of ground-based receivers, one file per site. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/hourly_30second_data.html.

Doppler Orbitography by Radiopositioning Integrated on Satellite (DORIS) Data (multi-day files) from the NASA Crustal Dynamics Data Information System (CDDIS). DORIS is a dual-frequency Doppler system consisting of a receiver flying aboard a satellite and a globally distributed network of ground beacons. The DORIS receiver on-board the orbiting satellite tracks the dual-frequency radio signals transmitted by the network of ground beacons and generates the DORIS data. A measurement is made of either the Doppler shift or absolute phase as the satellite’s orbit moves over the ground-based beacon. DORIS data records contain a time-tagged range-rate measurement with associated ancillary information. The data records also contain information about any corrections that may have been applied during the processing phase, such as for the ionosphere, troposphere, and satellite center of mass, among others. Furthermore, meteorological measurements (e.g., temperature, relative humidity, ground pressure) recorded by instruments co-located with the ground-based beacons are included with the DORIS data and can be used to determine the tropospheric correction. DORIS data in the original format are also supplied to the data center in multi-day files, corresponding to the mission’s data processing arc, and are forwarded approximately 20 days after the end of the last observation day contained in the file. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/DORIS/DORIS_data_holdings.html.

This dataset consists of ground-based Global Navigation Satellite System (GNSS) Quasi-Zenith Satellite System (QZSS) Broadcast Ephemeris Data (daily files) 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 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. The daily QZSS broadcast ephemeris files contain one day of QZSS broadcast navigation data in RINEX format from a global permanent network of ground-based receivers, one file per site. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/daily_30second_data.html.

This dataset consists of ground-based Global Navigation Satellite System (GNSS) Observation Data (30-second sampling, hourly files) 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. The hourly GNSS observation files (un-compacted) contain one hour of GPS or multi-GNSS observation (30-second sampling) data in RINEX format from a global permanent network of ground-based receivers, one file per hour per site. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/hourly_30second_data.html.

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. The daily GNSS observation files (un-compacted) contain one day of GPS or multi-GNSS observation (30-second sampling) data in RINEX format from a global permanent network of ground-based receivers, one file per site. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/daily_30second_data.html.

Global Navigation Satellite System (GNSS) daily 30-second sampled data available from the Crustal Dynamics Data Information System (CDDIS). Global Navigation Satellite System (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). 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) are similar to the U.S. GPS in terms of the satellite constellation, orbits, and signal structure; CDDIS began archiving data from these systems in 2011. These data include hourly files of observation (30-second sampling), broadcast ephemeris, meteorological messages in RINEX format as well as other files (e.g., hourly meteorological data) from a global network of permanent ground-based receivers.

This dataset consists of ground-based Meteorological Data (daily, 24 hour files) from instruments co-located with Global Navigation Satellite System (GNSS) GLONASS receivers from the NASA Crustal Dynamics Data Information System (CDDIS). GNSS provide autonomous geo-spatial positioning with global coverage. The GLONASS data sets from ground receivers at the CDDIS consist of observations from the Russian GLObal NAvigation Satellite System (GLONASS); Russia's GLONASS is similar to the U.S. GPS in terms of the satellite constellation, orbits, and signal structure. The daily meteorological data files contain one day of meteorological data (temperature, pressure, humidity, etc.) in RINEX format from a global permanent network of ground-based receivers, one file per site. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/daily_30second_data.html.

Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) Data (multi-day files) from the NASA Crustal Dynamics Data Information System (CDDIS). DORIS is a dual-frequency Doppler system consisting of a receiver flying aboard a satellite and a globally distributed network of ground beacons. The DORIS receiver on-board the orbiting satellite tracks the dual-frequency radio signals transmitted by the network of ground beacons and generates the DORIS data. A measurement is made of either the Doppler shift or absolute phase as the satellite’s orbit moves over the ground-based beacon. DORIS data records contain a time-tagged range-rate measurement with associated ancillary information. The data records also contain information about any corrections that may have been applied during the processing phase, such as for the ionosphere, troposphere, and satellite center of mass, among others. Furthermore, meteorological measurements (e.g., temperature, relative humidity, ground pressure) recorded by instruments co-located with the ground-based beacons are included with the DORIS data and can be used to determine the tropospheric correction. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/DORIS/DORIS_data_and_product_archive.html.

Ionosphere Total Electron Content (TEC) grids derived from analysis of Global Navigation Satellite System (GNSS) data. These products are the generated by analysis centers in support of the International GNSS Service (IGS) and combined by the IGS ionosphere analysis coordinator to form the official IGS rapid ionosphere product (daily).

This dataset consists of ground-based Meteorological Data (daily, 24 hour files) from instruments co-located with Global Navigation Satellite System (GNSS) receivers 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. The daily meteorological data files contain one day of meteorological data (temperature, pressure, humidity, etc.) in RINEX format from a global permanent network of ground-based receivers, one file per site. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/daily_30second_data.html.

Satellite and receiver clock products derived from analysis of Global Navigation Satellite System (GNSS) data. These products are the generated by analysis centers in support of the International GNSS Service (IGS) and combined by the IGS analysis coordinator to form the official IGS real-time clock product (daily). This product is used for comparison purposes.

This dataset consists of ground-based Global Navigation Satellite System GLONASS Observation Data (30-second sampling, daily files) from the NASA Crustal Dynamics Data Information System (CDDIS). GNSS provide autonomous geo-spatial positioning with global coverage. The GLONASS data sets from ground receivers at the CDDIS consist of observations from the Russian GLObal NAvigation Satellite System (GLONASS); Russia's GLONASS is similar to the U.S. GPS in terms of the satellite constellation, orbits, and signal structure. The daily GLONASS GNSS observation files (un-compacted) contain one day of GLONASS observation (30-second sampling) data in RINEX format from a global permanent network of ground-based receivers, one file per site. More information about these data is available on the CDDIS website at https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/daily_30second_data.html.

Global Navigation Satellite System (GNSS) data consists of the U.S. Global Positioning System (GPS) and the Russian GLObal NAvigation Satellite System (GLONASS) (plus other international systems) data sets. The Global Positioning System, developed by the U.S. Department of Defense, has been fully operational since 1994. GPS consists of a constellation of 24 satellites and three active spares each traveling in a 12 hour circular orbit, 20,200 kilometers above the Earth. The satellites are positioned so that six are observable nearly 100 percent of the time from any point on the Earth. The GLObal NAvigation Satellite System (GLONASS), managed and deployed by the Russian Federation, is similar to the U. S. Global Positioning System (GPS) in terms of the satellite constellation, orbits, and signal structure. GNSS receivers detect, decode, and process signals from the GNSS satellites. The satellites transmit the ranging codes on two radio-frequency carriers, allowing the locations of GNSS r

Miscellaneous documentation, information, and ancillary data to be used with GNSS, laser ranging, VLBI and DORIS data and analyzed products available through the CDDIS.

SLR Satellite Orbit solutions available from the Crustal Dynamics Data Information System (CDDIS). Precise Orbit Determination (POD) solutions in Standard Product 3 (SP3) format derived from analysis of Satellite Laser Ranging (SLR) data. These products are the generated by analysis centers in support of the International Laser Ranging Service (ILRS) and combined by the ILRS analysis coordinator to form the official ILRS orbit product (weekly), available approximately 5 days after the end of the solution week.