The Solar Backscatter Ultraviolet Radiometer (SBUV/2) is a nadir-pointing nonspatial spectrally scanning ultraviolet radiometer carried in two modules. The two modules are the Sensor Module with the optical elements/detectors and the Electronics Module. The overall radiometric resolution is approximately 1 nanometer (nm). Two optical radiometers form the heart of the instrument: a monochrometer and a "Cloud Cover Radiometer" (CCR). The monochrometer measures the Earth radiance directly and selectively the Sun when a diffuser is deployed. The CCR measures the 379-nm wavelength and is coaligned to the monochrometer. The output of the CCR represents the amount of cloud cover in a scene and is used to remove cloud effects in the monochrometer data.
The SBUV/2 measures solar irradiance and Earth radiance (backscattered solar energy) in the near ultraviolet spectrum (160 to 400 nm). The following atmospheric properties are measured from this data: