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. GIFTS will enhance the polar orbiting imaging and sounding measurements by providing: (1) a direct measure of moisture flux and altitude-resolved water vapor and cloud tracer winds throughout the troposphere, (2) an observation of the time varying atmospheric thermodynamics associated with storm system development, and (3) the transport of tropospheric pollutant gases (i.e., CO and O3). The GIFTS instrument will be completed in late 2005 to support a 2006 to 2008 launch opportunity. GIFTS will conduct the “proof of concept” mission for the Hyperspectral imaging and sounding systems to fly on future operational geosynchronous satellites.

This paper provides an overview of the GIFTS measurement concept. The high altitude aircraft NPOESS Airborne Sounder Test-bed (NAST) interferometer radiance spectra, and Aqua satellite AIRS and MODIS radiance measurements are used to demonstrate the retrieval algorithms to be used for processing the data as well as to empirically validate the imaging and sounding product accuracies expected from the GIFTS. Wind profiles obtained from a time sequence of NAST water vapor retrieval images, observed from the NASA ER-2 flying off the Pacific coast, are validated using Doppler LIDAR winds, obtained simultaneously from a Navy Twin Otter aircraft under flying the NASA ER-2. “Lessons Learned” from the GIFTS development and the analysis of NAST, AIRS, and MODIS data will be discussed with respect to their implications for the GOES-R series HES requirements and anticipated performance.