Revised collection of original group counts: description
This is the current primary archive of all raw group counts collected to build the Group Number series. This new collection is based on the initial version collected by Hoyt and Schatten (1998) to build the original Group Number series (Version 1.0).
The main changes are the elimination of a considerable number of observations during the Maunder Minimum (https://en.wikipedia.org/wiki/Maunder_Minimum), the inclusion of newly recovered observations from historical observers, and also the addition of multiple long-duration series by visual observers over the 20th century (Some of the latter are extracted from the SILSO Sunspot Number database, after 1981). Those modern visual series now complement or replace the Greenwich photographic catalogue that was the main data set used by Hoyt and Schatten for the Group Number Version 1.0 over the time interval 1875-1976, but proved to suffer from strong inhomogeneities over the time interval 1885-1915.