  Ground-based whole sky imagers (WSIs) can provide localized images of the sky
of high temporal and spatial resolution, which permits fine-grained cloud
observation. In this paper, we show how images taken by WSIs can be used to
estimate solar radiation. Sky cameras are useful here because they provide
additional information about cloud movement and coverage, which are otherwise
not available from weather station data. Our setup includes ground-based
weather stations at the same location as the imagers. We use their measurements
to validate our methods.
