NPOESS Airborne Sounder Testbed - Interferometer (NAST-I)


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The National Airborne Sounder Testbed-Interferometer (NAST-I) is a high spectral resolution (0.25cm-1) and high spatial resolution (0.13 km linear resolution per km of aircraft flight altitude, at nadir) scanning (2.3 km ground cross-track swath width per km of aircraft flight altitude) interferometer sounding system that was developed to be flown on high-altitude aircraft to provide experimental observations needed to finalize the specifications and to test proposed designs and data processing algorithms for the Cross-track Infrared Sounder (CrIS) flying on the Suomi NPP (SNPP) and Joint Polar Satellite System (JPSS) platforms. Because the NAST-I infrared spectral radiance and temperature, humidity, trace species, cloud and surface property soundings have unprecedented spectral and high spatial resolution, respectively, the data can be used to support a variety of satellite sensor calibration / validation and atmospheric research programs. The NAST-I covers a spectral range from ~ 600-2900 cm-1 (3.5-16 microns) with 0.25 cm-1 spectral resolution, yielding more than 9000 spectral channels of radiance emission/absorption information. The NAST-I passive infrared (IR) Michelson interferometer is often flown with the NAST passive microwave sounding instrument (NAST-M, from MIT LL) to provide an all-weather sounding capability. The NAST-I instrument has flown numerous science missions on the ER-2, WB-57, and Proteus aircraft, and the team has evaluated efforts needed to become operational on the DC-8. Additional information can be obtained from Anna Noe (, 757-864-6466) or Dr. Allen Larar (, 757-864-5328).

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