Physikalisch-Metorologisches Observatorium Davos -- World Radiation Center pmod-wrc


A Satellite Experiment to Monitor the Solar Irradiance at Selected Wavelengths (Instrument-PI: Werner Schmutz PMOD/WRC)

PREMOS General Description

>> PREMOS is a 4-channel filter radiometer
>> Wavelengths: 215, 268, 535 and 782 nm
>> It has 3 identical radiometer heads in order to assess a possible degradation
>> It will be flown on the French microsatellite PICARD

The PICARD Mission

French microsatellite, scheduled for launch in 2006 (PI G. Thuillier, homepage)

Science aim: relation between the solar diameter, differential rotation and solar constant as well as their intrinsic variabilites. PICARD will carry the following instruments:

SODISM: Solar imager aimed at measuring the solar diameter at 4 different wavelengths
SOVAP: Absolute Radiometer measuring the total solar irradiance
PREMOS: 4-channel precision filter radiometer  

>> Assembled view of PREMOS
>> Exploded view of PREMOS

>> Exploded view of a 4-channel filter radiometer

PREMOS Science Motivation

How is the Earth's climate affected by solar spectral (in particular UV) irradiance variations?
Is the theoretical interpretation of solar irradiance variations correct?
Provide precise intensity observations to support SODISM's diameter measurements.

Proposed Research
The UV solar irradiance strongly affects the formation of stratospheric ozone which is a crucial parameter for the Earth's energy budget. PREMOS measurements will consequently be used (together with the TSI measurements of SOVAP and the images of SODISM) as input for GCM simulations in order to investigate the response of the Earth's atmosphere to the solar irradiance variations The combined use of PREMOS's absolute spectral measurements with the TSI of SOVAP and the images of SODISM will enable to verify  and refine the current theoretical understanding of solar irradiance variations by localizing the features responsible for the variability at specific wavelengths.

<< overview space projects
Dorfstrasse 33, CH-7260 Davos Dorf, Phone +41 58 467 51 11, Fax +41 58 467 51 00