Radio - Propagation

Solar activity

	Solar activity Factor I - period from 22/09/1999 till 06/06/2002
	Solar activity Factor I - period from 22/09/1999 till 06/06/2002

Source: OH2AQ and others. (plots by ON6JC/LW3HAZ)

	Recent solar activity - Number of sunspots and annual mean number of spots.
	Historical sun activity - Number of sunspots and annual mean number of spots.

Source of this information: Royal Observatory of Belgium

1831