Operational high-spectral-resolution infrared radiance measurements from the geostationary perspective will be introduced on GOES-R with the HES (Hyperspectral Environmental Suite) - Infrared. These advanced sounders will have hundreds of channels with spectral widths less than a wavenumber; the current GOES Sounders have 18 bands with spectral widths of tens of wavenumbers. The HES-IR has been designed to improve geostationary sounding capabilities by expanding the hourly spatial coverage, increasing the vertical temperature and moisture sounding resolution, capturing atmospheric motions at many more levels, and penetrating the boundary layer to depict small scale temperature and moisture changes. These improved capabilities will significantly impact nowcasting, short-range weather forecasting, and longer-range numerical weather prediction.

HES-IR will have two modes of operation - hemispheric Disk Soundings (DS) and Severe Weather Mesoscale (SW/M) soundings. DS will provide 10 km spatial resolution; selected spectral measurements between 4 and 15 microns, and full disk coverage (out to 62 degrees local satellite zenith angle) every hour. SW/M reduces the coverage to 1000 x 1000 km area while increasing the frequency to 5 minutes and the resolution to 5 km; SW/M will be directed to regions where severe thunderstorms, hurricanes, or severe winter storms are pending or to areas targeted by numerical forecast models.

HES-IR goals include (1) identifying small scale features of moisture vertically and horizontally; (2) detecting clear-sky low-level atmospheric inversions; (3) tracking atmospheric motions in more levels with accurate height assignments; (4) providing better viewing between clouds and near cloud edges; (5) enabling accurate land and sea surface temperature determinations in addition to IR surface emissivity estimates; (6) distinguishing atmospheric constituents with improved certainty, including dust, volcanic ash, and ozone.