CDDIS OVERVIEW THE CDDIS DATA CENTER — DATA FLOW FOR INTERNATIONAL SERVICES

The Crustal Dynamics Data Information System (CDDIS) is a dedicated data center supporting the Network Stations international space geodesy community, providing easy and ready access to a variety of data sets, products, NASA'S SPACE GEODESY DATA ARCHIVE Continuously operational Analysis Centers/User Community and information about these data. The data center was established in 1982 as a dedicated data bank to Timely flow of data archive and distribute all Crustal Dynamics Project-acquired data and information about these data. Today, Carey Noll and Maurice Dube Data Centers the CDDIS continues to serve as the NASA archive and distribution center for space geodesy data, particularly Compressed Data Files (in data type-specific formats) Interface to network stations Global Positioning System (GPS), Global Navigation Satellite System (GLONASS), laser ranging, Very Long NASA GSFC Perform QC and data Baseline Interferometry (VLBI), and Doppler Orbitography and Radiopositioning Integrated by Satellite conversion activities (DORIS) data. The specialized nature of the CDDIS lends itself well to enhancement to accommodate diverse Archive data for access to Global Data Centers data sets and user requirements. analysis centers and users

The CDDIS serves as one of the primary data centers for the following International Association of Geodesy Analysis Centers

i r e c t n g B o a d Compressed Data Files (in data type-specific formats) Provide products to users

(IAG) services: a l B u r e • International GPS Service (IGS) (e.g., station coordinates, • International Laser Ranging Service (ILRS) Operational/Regional Data Centers precise satellite orbits, Earth C e n t r • International VLBI Service for Geodesy and Astrometry (IVS) orientation parameters, • International Earth Rotation Service (IERS) IGS DATA AND PRODUCTS ILRS DATA AND PRODUCTS atmospheric products, etc.) G o v e r n i g / D • International DORIS Service (IDS) Raw Data Central Bureau The International Laser Ranging Service (ILRS), operational since The main mission of the International GPS Service (IGS) is to provide a Management of service 1998, provides global satellite and lunar laser ranging data and Operational data centers deposit data to individual user accounts on the CDDIS host computer. All data are service to support geodetic and geophysical research activities through GPS Facilitate communications data and products. This service has been operational since 1994. The their related products to support geodetic and geophysical research processed to ensure data integrity and to extract pertinent metadata. These metadata are loaded into a GPS GLON SLR VLBI DORIS Coordinate activities relational database for data tracking and query purposes. Data are then copied to public directories and current network consists of nearly 300 permanently occupied, globally IGS an accurate International Terrestrial Reference Frame (ITRF). The service develops the made available to the user community through anonymous ftp and the web. distributed sites that provide GPS data to IGS data centers on a daily, Governing Body necessary global standards/specifications and encourages international adherence to its Space Geodesy Network Stations hourly, and near-real-time basis. These GPS data are used by the IGS General oversight of service conventions. The ILRS collects, merges, archives and distributes Satellite Laser Ranging The CDDIS is operational on a UNIX server with over 550 Gbytes of on-line disk storage. A majority of the analysis centers to generate products such as precise satellite ephemerides Future direction and clock information. (SLR) and Lunar Laser Ranging (LLR) observation data sets of sufficient accuracy to satisfy archive is devoted to the archive of GPS data and products. the objectives of a wide range of scientific, engineering, and operational applications and GLOBAL GPS, GLONASS, LASER, VLBI, AND DORIS NETWORKS experimentation. In 2001, over 2.2 million files totaling over 150 Gbytes in size were downloaded each month from the CDDIS GPS (and GLONASS) Data: on-line archive. More than 6,700 distinct hosts in 95 countries accessed and downloaded data from the • Daily files containing 30-second sampled GPS data in RINEX format Laser Data: Ny Ålesund CDDIS last year. Over 120 institutions in over sixty countries supply data to the CDDIS on a daily basis for Thule - 200+ GPS (and ~50 GLONASS) stations/day • Daily and monthly files containing on-site normal points, - Approximately 0.35 Mbytes/site/day in size (compressed) 75° sorted by satellite, in ILRS normal point format Resolute - Data since January 1997 on-line • Hourly files containing on-site normal points from all Retroreflector array on Jason, Holman Island Tiksi GODE GPS antenna at Tromsø CDDIS ARCHIVE STATISTICS • Hourly files of 30-second sampled GPS data in RINEX format satellites, in ILRS normal point format retained for five GFO-1, ICEsat, and ADEOS-II Greenbelt, MD Inuvik Kiruna Bilibino - 115+ GPS (and 16 GPS/GLONASS) stations/day CDDIS photograph ILRS web site photograph Kangerlussuaq days Fairbanks Noril'sk Reykjavík Höfn Yellowknife - Approximately 0.02 Mbytes/site/hour in size (compressed) Whitehorse GjØvik Yakutsk • Daily and monthly full-rate data files from a subset of the Metsahovi Maartsbo Magadan 60° Churchill Svetloe - Data retained for three days BorasVisby Arti Number of GPS, GLONASS, Laser Ranging, VLBI and DORIS Files Retrieved from the CDDIS global network, sorted by satellite, in ILRS full-rate Onsala Krasnoyarsk Leipzig Riga Mendeleevo Novosibirsk Flin Flon Braunschweig Schefferville Helgoland Neustrelitz Zweningorod • Fifteen-minute files of one-second sampled GPS data in RINEX format Williams Lake TeddingtoKnootwijk Potsdam Borowiec Irkutsk Komsomolsk format Priddis Westerbork Delft Dresden Olsztyn Petropavlovsk- (2001) Holberg Whistler Herstmonceux ETiftfzelsberg Jozefoslaw Kamchatsky Nanoose Bay Lac du Bonnet BrusFseralsnkfurt WroclawLviv Kiev Badary Penticton Wettzell Ondrejov UzhgorPoodltava Ucuelet Chiliwack ObeSrèpvfareffsenhofen Mattersburg - 40+ GPS stations/day LAGEOS satellite Albert Head Brewster Gatineau St. John's HuegeInlhnesibmruHkuegleGhreaizmPenc Yuzhno-Sakhalinsk • Currently, 26 satellites and four sites on the moon are Woodinville Algonquin Ottawa Fredericton Zimmerwald Padova Bucharest Simeiz La Rochelle Genova Venezia Khantau Chumysh 45° 10,000,000 ILRS web site photograph Hancock Eastport Toulouse Osijek Katzively Zelenchukskaya Almaty Urumqi Changchun North Liberty Bar Harbor GrassMeedicina Talas Westford Villafranca Yebes SofiaIstanbul Kumtorkala l'Ebre Dubrovnik Ohrid Yerevan Bishkek - Approximately 0.45 Mbytes/site/hour in size (compressed) Quincy Colorado Springs Greenbelt Gebze Shamsi Beijing Mizusawa tracked on a routine basis by 40 SLR and LLR stations Green Bank Madrid Matera Ankara Trabzon Southern California Owens Valley Mammoth Lakes San Fernando Cagliari Maidenak Suwon-shi Washington, D.C. Chesapeake Bay Ponta Delgada Dionysos Diyarbakir Kitab Tsukuba Integrated GPS Network Goldstone Noto Nicosia Purple Mountain Taejon Usuda (over 50 sites) Los Alamos (3 sites) Simosato Mitaka - Data since May 2001 on-line Monument Peak Pie Town Rabat Amman Xi'an TokyoKashima • Approximately 1 Mbyte/day on-site normal point data Bermuda Shanghai Miura Ensenada Kitt Peak Metzoki Dragot Mitzpe Ramon Wuhan 30° McDonald Fort Davis Helwan Lhasa Koganei Richmond Tateyama • Daily files of ten-second sampled satellite-borne GPS receive data GPS satellite Maspalomas Bahrain Kunming 1,000,000 (uncompressed); 2 Mbytes/day full-rate data Key Biscayne Freeport Riyadh Mt. Everest Taipei Kokee Park Lihue Solcorro Island Haleakala Santiago de Cuba Smithsonian Institution photograph Honolulu Aguascalientes Mauna Kea Manzanillo St. Croix in RINEX format Hilo Kingston Palmeira Arlit Manila (compressed) Guatemala City Tegucigalpa Dakar Quezon City 15° San Salvadore Esteli Barbados Taal San Lorenzo Managua Bangalore Kaygabok Guam - Two satellites (SAC-C, CHAMP); JASON, GRACE to be archived Yamoussoukro • CDDIS laser data archive: 1976 through present; Limón Djibouti Kwajalein Bogotá Kourou Male Colombo Singapore 100,000 - Approximate 2.5 Mbytes/satellite/day in size (compressed) Libreville Mbarara 0° approximately 90% of data holdings available on-line Galapagos Islands Riobamba Fortaleza Franceville Seychelles Malindi Diego Garcia Cibinong Lae Ascension Bakosurtanal - Data since January 2002 on-line Futuna Port Moresby American Samoa Cocos Islands Jabiru -15 Faleolo Brasilia Darwin ° Arequipa Sainte-Helene Suva Tahiti La Reunion Townsville Koumac Karratha Salta Alice Springs Nouméa Cachoeira Paulista Pretoria 10,000 Rapa Easter Island ILRS Products (future): Hartebeesthoek Richard's Bay Brisbane -30° Caucete Cordoba Yaragadee (2) Ceduna IGS Products: Valparaiso Sutherland Perth • Precise satellite ephemerides Santiago Tristan de Cunha Tidbinbilla Lindfield SLR 2000 prototype system at Greenbelt, MD La Plata Amsterdam Island Mt. Stromlo • Precise GPS satellite ephemerides (<5 cm accuracy) ILRS web site photograph Gough Island Auckland Chatham Islands Hobart -45° • Earth rotation parameters Coyhaique Dunedin 1,000 Marion Island Kerguélen Macquarie Island • IGS tracking station coordinates and velocities Punta Arenas FAIR GPS antenna at Rio Grande • GPS satellite and IGS tracking station clock information Fairbanks, AK IGS photograph • Global ionosphere maps of total electron content (TEC) IDS DATA AND PRODUCTS -60° 100 O'Higgins Palmer Casey Terre Adéle N u m b e r o f F i l s ( L g a t h c S ) GPS Site Rothera The DORIS system, developed in France, is based on the measurement of GLONASS Mawson Davis SLR Site Sanae Doppler shifts in radio signals, transmitted by ground beacons to a DORIS VLBI Site Syowa 10 DORIS Site receiver on-board the satellite. Like GPS and SLR, precise satellite -75° South Pole IVS DATA AND PRODUCTS orbits, positions of and distances between observing stations, and Earth McMurdo -165° -150° -135° -120° -105° -90° -75° -60° -45° -30° -15° 0° 15° 30° 45° 60° 75° 90° 105° 120° 135° 150° 165° rotation, orientation, and polar motion values can be derived from DORIS 1 Products generated by International VLBI Service for Geodesy and Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec measurements. The primary objective of the International DORIS Service Astrometry (IVS) contribute to research in many areas, including solid (IDS) is to foster the DORIS technique to support international geodetic, Month (2001) FOR FURTHER INFORMATION Earth, tides, studies of the vertical, and VLBI technique improvement. geophysical, and other research and operational activities. GPS GLONASS Laser VLBI DORIS The objectives of IVS are to provide a service to support geodetic, DORIS on-board receiver Carey Noll IDS web site photograph geophysical, and astrometric research and operational activities, to Manager, CDDIS promote research and development for VLBI, and to interact with users DORIS Data: NASA GSFC of VLBI products • Files containing one "cycle" (~ten days) of data (computed Greenbelt, MD 20771 USA Number of GPS, GLONASS, Laser, VLBI, and DORIS Number of GPS, GLONASS, Laser, VLBI, and DORIS range measurements), sorted by satellite, in DORIS-specific format [email protected] Files Retrieved in 2001 Files Retrieved in 2001 • Seven satellites have on-board DORIS receivers that receive (By Host Type) (By Geographic Area) VLBI Data: transmitted signals from a network of nearly 50 beacons Maurice Dube • VLBI data bases in DBH and NGS card formats 1% • Approximately 5 Mbyte/satellite/cycle (compressed) Raytheon ITSS 1% <1% <1% <1% • Auxiliary files (e.g., log, met data, schedule, cable info, • CDDIS DORIS data archive: 1992 through present; all data Lanham, MD 20706 4% <1% correlator notes, etc.) available on-line USA 9% [email protected] 26% • Currently, over 40 antennas participate in the IVS Commercial North America • Approximately 2-3 Mbyte/data base file (compressed) Education South America CDDIS Web Site: http://cddis.nasa.gov or • CDDIS VLBI data archive: 1979 through present; most VLBI antenna at Government Europe Fairbanks, AK IDS Products (future): DORIS antenna located in http://cddisa.gsfc.nasa.gov Hartebeesthoek, South Africa Network Asia data holdings available on-line IVS web site photograph 57% • Precise satellite ephemerides IGN web site photograph Non-Profit 29% Africa • Site coordinates and velocities; position time series Unknown Australia DORIS satellite antenna 62% • Earth rotation parameters AVISIO web site photograph Pacific 11% IVS Products: Part of the celestial reference • Special products frame defined by VLBI • Intensive and session Earth orientation parameter IVS web site photograph - Ionosphere information series (EOP-I and EOP-S) - Time varying geocenter coordinates CEN 05/17/2002