In 1947, Covington, who was working near Ottawa, for the National Research Council of Canada, found that World War II era radar was useful for measuring solar flux density at 10.7 cm. Scientists subsequently noticed that these readings varied from year to year, and that the variations were closely correlated with sunspot count numbers.

Although solar radio emissions occur over wavelengths ranging from radio to shorter than optical, 10.7 cm is especially useful in sunspot physics and solar flux at this wavelength has been designated as the ‘solar flux index’. It is normally published in “Solar Flux Units” (SFU) where 1 SFU is 1*10^-22 W m^-2 Hz^-1.

The 10_7cmLog.sqlite database contains raw daily data. The 10_7Log_2012XX.csv files are monthly results from the 107_log.SQL which creates the SFU number as average Min - Max value from the log_data table in the Sqlite3 database.  To recreate these .csv files download the 10_7cmLog.sqlite database and run the 107_log.SQL. The Sqlite3 application comes from here:  http://sqlitebrowser.sourceforge.net/ http://www.sqlite.org/download.html 

PI: Rodney Howe