The solar irradiance used as a reference light source is a key point for measurements in aeronomy. The radiometry laboratories at BIRA-IASB are equipped accordingly.
Humans have developed instrumentation to measure the spectral shape of sunlight. BIRA-IASB contributed to this quest with the SOLAR/SOLSPEC instrument on board the ISS.
The assessment of the radiometric performances of both spatial and ground-based instruments, measuring the solar spectrum, is done in BIRA-IASB’s radiometric laboratories.