GIFTS - the precursor geostationary satellite component of the future Earth Observing System

The Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) combines advanced technologies to observe surface thermal properties and atmospheric weather and chemistry variables in four dimensions. Large area format Focal Plane detector Arrays (LFPAs) provide near instantaneous large area coverage with high horizontal resolution. A Fourier Transform Spectrometer (FTS) enables atmospheric radiance spectra to be observed simultaneously for all LFPA detector elements thereby providing high vertical resolution temperature and moisture sounding information. The fourth dimension, time, is provided by the geosynchronous satellite platform, which enables near continuous imaging of the atmosphere´s three-dimensional structure. The key advances that GIFTS achieves beyond current geosynchronous capabilities are: (1) the water-vapor winds will be altitude-resolved throughout the troposphere, (2) surface temperature and atmospheric soundings will be achieved with high spatial and temporal resolution, and (3) the transport of tropospheric pollutant gases (i.e. CO and O₃) will be observed. GIFTS will be launched in 2005 as NASA´s third New Millennium Program (NMP) Earth Observing (EO-3) satellite mission, and will serve as the prototype of sounding systems to fly on future operational geosynchronous satellites. After a one-year validation period in view of North America, the GIFTS will be repositioned to become the Navy´s Indian Ocean METOC Imager (IOMI). We describe the GIFTS technology and provide examples of the GIFTS remote sensing capabilities using aircraft interferometer data. The GIFTS is an important step in implementing the NASA Earth Science Enterprise vision of a sensor web for future Earth observations.