GROUND-BASED CLOUD IMAGES AND SKY RADIANCES IN THE VISIBLE AND NEAR INFRARED REGION FROM WHOLE SKY IMAGER MEASUREMENTS

Automatic cloud documentation from the ground is one of the basic tools to set up cloud climatologies with high resolution in space and time. Ground-based cloud data are of specific importance to study the role of clouds on the radiation balance of the earth's surface and the lower atmosphere. They can also provide ground-truth information for satellite-retrieved cloud parameters. A new version of the Whole Sky Imager (WSI) was designed and developed at the University of California, San Diego (UCSD) for Deutscher Wetterdienst (DWD), and installed at the Meteorological Observatory Potsdam of DWD in December 1999. The new WSI design will be discussed, and first results of measure-ments be presented. 1