ISO 21348:2007 specifies the process for determining solar irradiances and is applicable to measurement sets, reference spectra, empirical models, theoretical models, and solar irradiance proxies or indices that provide solar irradiance products representing parts or all of the solar electromagnetic spectrum. Its purpose is to create a standard method for specifying all solar irradiances for use by space systems and materials users.
BS ISO 21348:2007 history
2007BS ISO 21348:2007 Space environment (natural and artificial). Process for determining solar irradiances