Direct and Standard Year Earth Radiation Data

Some of these stations made continuous recordings on strip charts; other stations only recorded the daily total energy (insulation) received. Much of these data were digitized at the station, using instructions that changed over the years, and were forwarded to regional centers (later centralized at the NCDC). During 1976, the network was essentially shut down while new equipment was purchased and installed.

When these data were evaluated, only 27 stations were deemed suitable for inclusion in a national data base.