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Into the Future with Metrology - The Challenges of Our Environment and Climate


An accurate view of the Sun

array spectroradiometer
An array spectroradiometer characterized at PTB faces the rising sun at the Izaña Atmospheric Observatory (IZO) in Tenerife during an international comparison measurement campaign to determine the ozone column.

The radiation of the Sun is partially absorbed by smaller components of the Earth's atmosphere that are among the most essential climate variables (such as ozone, nitrogen oxides, water vapor and aerosols) or partially reflected back into space. On the basis of radiometric measurements of terrestrial solar radiation, the respective essential climate variables can therefore be determined. And furthermore, the effects on health (UV radiation) or on the energy production in PV systems can be quantified. PTB has been cooperating closely with the Physical Meteorological Observatory Davos/World Radiation Center for many years to enable the traceability of solar measurements and of derived quantities such as the ozone column and the column-integrated optical properties of aerosols to the SI with the smallest possible uncertainties. For this purpose, the national standard for the spectral irradiance (a high-temperature blackbody radiator) as well as the spectrally tunable laser systems of PTB are used to calibrate the required spectrally resolving and spectrally integrating measuring instruments.

Participating department
Opens internal link in current window4.1 Photometry and Spectroradiometry