Sunspot Number [SSN]


    Is a quantity that measure the number of sunspots and groups of sunspots observed on the surface of the sun in a time window.

    A daily index of sunspot activity (R), defined as R = k(10g + s) where s = number of individual spots, g = number of sunspot groups, and k is an observatory factor (equal to 1 for the Zurich Observatory and adjusted for all other observatories to obtain approximately the same R number). The standard number, RI, once derived at Zurich (see Wolf number), is now being derived at Brussels and is denoted by RI. Often, the term ”sunspot number” is used in reference to the widely distributed smoothed sunspot number.

    Wolf number
    Categories: Propagation
    « Back to Glossary Index
    Previous articleSunspot
    Next articleSolar Cycle
    The DXZone merges amateur radio and Internet, since early internet days. Established in 1996 as a radio-related-mailinglist, has registered its domain name in 1998. Main goal is to review and promote ham-radio web sites, classifying them in categories. The DXZone is managed by ham radio operators with ham radio operators in mind.