Detection of cloud cover fractions by GOME Polarization Measurement Detectors and validation by surface observations

摘要

The GOME instrument on board of the European Space Agency's ERS-2 satellite is a nadir viewing across track scanning spectrometer measuring the reflectivity of the earth in the visual spectral range and it has a spatial resolution of 320 x 40 km. The same wide swath is also seen by three broad band Polarization Measurement Detectors (PMDs) in the same instrument with a hgiher spatial resolution of 20 x 40 km, thus dividing the wide swath into 16 smaller sub-pixels. The Polarization Cloud recognition Algorithm is used to calcualte a cloud cover fraction. This work shows some results of a comparison between calculated cloud fractions from the PMDs and co-located surface observations in the Netherlands for August 1997, 1998 and 1999.