Infrared Hyperspectral Spectrometer Spectral Calibration

The National Oceanic and Atmospheric Administration’s (NOAA’s) Geostationary eXtended Observations (GeoXO) series satellites are planned to follow the Geostationary Operational Environmental Satellite (GOES)-R series satellites in 2032 and beyond. GeoXO will provide the nation continuity of environmental imagery over the western hemisphere, with observational improvements where feasible. The GeoXO Sounder (GXS) will provide level 1b calibrated and navigated radiances in the midwave infrared (MWIR) and the longwave infrared (LWIR) for vertical profiles retrievals of atmospheric temperature and moisture. GXS data and associated retrievals will not only be employed by National Weather Service (NWS) forecasters in near real time, but also will be used for numerical weather prediction (NWP) models. For NWP to fully utilize GXS data, the GXS spectral information must be precisely captured and spectrally corrected for any instrument artifacts, if needed, onto a fixed spectral grid that is temporally stable. The GXS requirements necessitate spectral stability at the level 1b for all spatial locations. A cross-correlation correction methodology was explored, employing a reference spectrum compared to shifted spectra. Existing polar orbital sounder data from NASA’s Atmospheric Infrared Sounder (AIRS) and NOAA’s Cross-track Interferometric Sounder (CrIS) were used to assess the variability of the correction under realistic conditions. Variations in the reference spectrum were also explored. Resulting analysis, supporting that GXS data could be corrected by this method, will be discussed.

Keywords:

• GOES-R follow-on, GeoXO instruments, GXS

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This material is based upon work supported by the Dept. of Commerce under Air Force Contract No. FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Dept. of Commerce.

* Correspondence e-mail: Owen.McElhinney@ll.mit.edu