SIDC http://sidc.oma.be

The Solar Influences Data Analysis Center — SIDC — is the solar physics research department of the Royal Observatory of Belgium, a data analysis service of the Federation of Astronomical and Geophysical data analysis Service, and the World Data Center for the Sunspot Index.

SIDC collects monthly observations from worldwide stations in order to calculate the International Sunspot Number, Ri. The center broadcasts the daily, monthly, yearly sunspot numbers, with middle-range predictions (up to 12 months). Since August 1992, it has also provided hemispheric sunspot numbers.

ROB has operated SIDC since 1981. In 2000, SIDC obtained the status of Regional Warning Center (RWC) of the International Space Environment Service (ISES) and became the "Solar Influences Data analysis Center."