The MODIS Airborne Simulator (MAS) is an airborne scanning spectrometer that acquires high spatial resolution imagery of cloud and surface features from its vantage point on-board a NASA ER-2 high-altitude research aircraft. This dataset has visible and infrared imagery calibrated to at-sensor radiance. Included are many associated browse files including the flight line tracks, and also text files of nadir brightness temperature and radiance for selected bands.