Solar radiometry
Abstract
The classical radiometry for total solar irradiance (TSI) measurements is described using examples of the four types of radiometers currently used in space. The design, characterization and operation of these radiometers are described. Besides the instrumental characteristics determining the measurement uncertainties, an important issue is possible long-term changes of the radiometers exposed to solar irradiance -- especially in the EUV -- and the space environment. A model for the degradation has been developed which can explain the behaviour of most radiometers in space. The TSI record since 1978 from different platforms and radiometers can be combined in a composite time series which demonstrates that although the assumed uncertainty of the present state-of-the-art radiometers is insufficient, their short- and long-term precision is good enough to produce a reliable time series of TSI over almost 30 years.
- Publication:
-
ISSI Scientific Reports Series
- Pub Date:
- 2010
- Bibcode:
- 2010ISSIR...9..525F