SURFRAD Total Sky Imagers (TSIs)
Image Data Archive:
Daily Cloud Cover Data:
GRAD collects data from Total Sky Imagers located at each SURFRAD site. The TSI consists of a web camera suspended over a convex mirror. The mirror has a black sun-blocking stripe, which rotates during the day to protect the camera's sensitive picture element from bright sunlight. Images of the sky are collected by a local computer, and processed into percent cloud cover data. Daily cloud cover data are available for all sites.