Distributed network of geomagnetic observations data storage in the system of World Data Centers (WDC)

Evgeniy P. Kharin, Geophysical Center of Russian Academy of Sciences, Russia

In the report, the analysis is given of changes in the kind, form and formats of data registration and presentation in the system of WDC beginning with the International Geophysical Year 1957 - 1958 (IGY 1957 - 1958) in the context of the progress of registration computer technologies and new possibilities of digital data collection and exchange.  The whole time period is subdivided into several stages with intervals that are rather conventional because technology does not show simultaneous progress in different countries.   

      Stage 1 - 1957-1970. This stage comprises analog magnetograms and hand processing of data to make tables of mean hourly values and to calculate various indexes of geomagnetic activity. Data are stored in the centers in the form of microfilms, analog magnetograms and tables of mean hourly values and indexes and in the form of the publications of tables and geomagnetic activity indexes.    

      Stage 2 - 1970-1980. This stage is characterized by analog magnetograms and hand processing of data to compile tables of mean hourly values. In the centers, data are stored in the form of microfilms and microfiches of analog magnetograms and tables of mean hourly values and geomagnetic activity indexes as well as in the form of publications of tables and magnetic activity indexes and a part of the tables is put into machine bearers (magnetic tapes) form by hand.   

      Stage 3 - 1980 - 1990.  The major network of observatories continues to work with analog magnetograms and hand processing of data to compile tables of mean hourly values and indexes but observatories began to be set up that registered geomagnetic field variation in machine-readable form. In the centers, data are stored in the form of microfilms and microfiches of analog magnetograms and tables of mean hourly values as well as in the form of publications of tables and geomagnetic activity indexes; a part of the tables is transferred into machine bearers that is magnetic tapes and copies of observatory data in machine-readable form.   

      Stage 4 - 1990-1995. Large-scale transfer of data in machine-readable form started. Both WDC and individual organizations transferred analog and tabular data into machine-readable form. Data were stored in magnetic tapes and diskettes.   

    Stage 5 - 1995- up to now. A considerable part pf observatories record data in machine-readable form and send data to WDCs or give them in their site in the Internet. The major part of one-minute and mean hourly values of geomagnetic field components is stored in WDC in machine readable form in CD ROM and DVD discs and is available for users in the Internet with free access.  

      The major feature of this stage is the wide use of the Internet to create all kinds of sites with access to observatories data. Observatories, laboratories, institutes and WDCs on geomagnetism and solar-terrestrial physics create the sites. The system of interactive data resource on solar-terrestrial physics (SPIDR) has been created, that is a distributed network of synchronous databases and application servers allowing us to select, visualize and model data on solar-terrestrial physics in the Internet and including the data of geomagnetic observatories network and geomagnetic indexes. 


Keywords: magnetograms, system of World Data Centers (WDC), digital data collection and exchange