The CAMEX-3 Multispectral Atmospheric Mapping Sensor (MAMS) dataset was collected by the Multispectral Atmospheric Mapping Sensor (MAMS), which is a multispectral scanner which measures reflected radiation from the Earth's surface and clouds in eight visible/near-infrared bands, and thermal emission from the Earth' surface, clouds, and atmospheric constituents (primarily water vapor) in four infrared bands. The 5.0 mRa aperture of MAMS produces an instantaneous field-of-view (IFOV) resolution of 100 m at nadir from the nominal ER-2 altitude of 20 km. The width of the entire cross path field-of-view scanned by the sensor is 37 km, thereby providing detailed resolution of atmospheric and surface features across the swath width and along the aircraft flight track. For clouds and thunderstorm features the IFOV decreases with increasing cloud height by a factor of (Z-20)/20, where Z is the cloud height in kilometers.