Estimation of incident solar radiation on the ground from multispectral satellite sensor imagery

A simple and fast, physically based method for the estimation of global radiation is presented. It is applicable for clear‐sky multispectral satellite sensor imagery with channels at least in the VNIR region and works without the need for additional ground data. The atmospheric influence is taken into account using look‐up tables based on standard atmospheres from the MODTRAN code. The algorithm was tested with a time series of nine Landsat‐7 ETM+ scenes of a region in north‐eastern Germany. Remotely sensed global radiation is in close agreement with in situ measurements of the German Meteorological Service as indicated by RMS deviations of 20–24 W m^?2 depending on the bands and atmospheric parameterization employed. The image‐derived global radiation at this level of accuracy is a useful supplement for studies in landscape ecology and related fields, for example as input for regional modelling of evapotranspiration.