CRYOGENIC SOLAR ABSOLUTE RADIOMETER (CSAR)

The Cryogenic Solar Absolute Radiometer (CSAR) is a new primary radiometric standard for use in space and traceable to the International System of Units (SI). The CSAR will be capable of measuring the total irradiance of the Sun with an uncertainty of 0,01 %, and a resolution of 0,001 %, more than a factor of ten improvement over existing instruments. The standard is at present under development and is part of a proposal, Absolute Radiometric Measurements in Space (ARMS), which has been submitted to the European Space Agency in response to a Call for Opportunities for Columbus Pre-Cursor Flights. The CSAR is currently on the provisional payload of EURECA III.