The Geostationary Imaging Fourier Transform Spectrometer (GIFTS) is a measurement concept which combines a number of advanced technologies, including particularly the Large area format Focal Plane detector Array (LFPA) with the Fourier Transform Spectrometer (FTS). The GIFTS will improve the observation of all three basic atmospheric state variables (temperature, moisture, and wind velocity) allowing much higher spatial, vertical, and temporal resolutions than is now achievable with currently operational geostationary weather satellites. The displacement of the measured water vapor and cloud features will be used as tracers of the transport of atmospheric water as well as other important constituents (e.g., CO and O3). A key advance over current geostationary wind measurement capabilities is that the water-vapor winds will be altitude-resolved throughout the troposphere. Thus, GIFTS observations will lead to a significantly better understanding of weather and climate processes, including the atmosphere’s water cycle and the transport of greenhouse and pollutant gases.

Because of limited fields of view, residence time limitations, and footprint movement, this significant improvement in measurement capacity cannot be fully demonstrated from aircraft or LEO. However, theEO-3 mission can conclusively prove the GIFTS breakthrough measurement concept for altitude-resolved water vapor winds and validate the key enabling technologies leading to an operational instrument. An advanced geostationary satellite sounding measurement capability will lead to improved weather and climate analysis and prediction. The improved soundings and other unique scientific products (e.g., the vertical distribution of water vapor flux), to be derived from an operational implementation of GIFTS, will enhance atmospheric research and operational meteorology on a routine and long-term basis.