Geostationary Imaging Fourier Transform Spectrometer (GIFTS): science applications

Abstract

A revolutionary satellite weather forecasting instrument, called the "GIFTS" which stands for the "Geostationary Imaging Fourier Transform Spectrometer", was recently completed and successfully tested in a space chamber at the Utah State University's Space Dynamics Laboratory. The GIFTS was originally proposed by the NASA Langley Research Center, the University of Wisconsin, and the Utah State University and selected for flight demonstration as NASA's New Millennium Program (NMP) Earth Observing-3 (EO-3) mission, which was unfortunately cancelled in 2004. GIFTS is like a digital 3-d movie camera that, when mounted on a geostationary satellite, would provide from space a revolutionary four-dimensional view of the Earth's atmosphere. GIFTS will measure the distribution, change, and movement of atmospheric moisture, temperature, and certain pollutant gases, such as carbon monoxide and ozone. The observation of the convergence of invisible water vapor, and the change of atmospheric temperature, provides meteorologists with the observations needed to predict where, and when, severe thunderstorms, and possibly tornados, would occur, before they are visible on radar or in satellite cloud imagery. The ability of GIFTS to observe the motion of moisture and clouds at different altitudes enables atmospheric winds to be observed over vast, and otherwise data sparse, oceanic regions of the globe. These wind observations would provide the means to greatly improve the forecast of where tropical storms and hurricanes will move and where and when they will come ashore (i.e., their landfall position and time). GIFTS, if flown into geostationary orbit, would provide about 80,000 vertical profiles per minute, each one like a low vertical resolution (1-2km) weather balloon sounding, but with a spacing of 4 km. GIFTS is a revolutionary atmospheric sensing tool. A glimpse of the science measurement capabilities of GIFTS is provided through airborne measurements with the NPOESS Airborne Sounding Testbed -Interferometer (NAST-I).

The generation and assimilation of continuous AMVs with 4DVar

“…Looking forward, the continuing trend to spacebased observations with higher spatial, temporal and spectral resolution should enable improved estimation of atmospheric flow and result in quantitative benefit to NWP. In the near future, the prospects of benefits from the expanded use of sequential observations from MTSAT 2, the Chinese satellite FY 2, and also from next generation ultraspectral instruments such as the Geostationary Imaging Fourier Transform Spectrometer (Smith et al 2000) are very good. It is also intended to exploit the characteristics of the new operational ACCESS 4DVar system to directly assimilate radiances, particularly from channels in the water vapour absorption band.…”

High-Spectral- and High-Temporal-Resolution Infrared Measurements from Geostationary Orbit

“…The finer spectral resolutions enable measurements of important changes that result from vertical structures in the atmosphere and other phenomena. Many aircraft observations have demonstrated the value of high-spectral-resolution IR data (e.g., Smith et al 1990). In addition, high-vertical-resolved water vapor profiles are accurately retrieved in order to drive atmospheric wind profiles; this was first demonstrated and documented with real data by the aircraft hyper-spectralresolution National Polar-Orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Test bed-Interferometer (NAST-I) measurements similar to the Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS; Zhou et al 2002;Velden et al 2005).…”

Technical Note: Evolution, current capabilities, and future advance in satellite nadir viewing ultra-spectral IR sounding of the lower atmosphere

“…The accuracy of the resulting wind profiles have been validated to be 4 m/s or less, depending upon altitude, using Doppler Wind Lidar (DWL) observation made from a Twin Otter aircraft (G. D. Emmitt, personal communication, 2003) which was flown beneath the ER-2 (Smith et al, 2006).…”