Point of Contact:

Bill Smith

NASA Langley Research Center
Mail Stop 401
Hamptop, VA 23681-2199

Office Telephone: (757) 864-5914

FAX: (757) 864-8197

E-mail: bill.l.smith@larc.nasa.gov

The NAST-I Homepage: http://cimss.ssec.wisc.edu/nast

The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Atmospheric Sounding Testbed (NAST) is a suite of airborne infrared and microwave spectrometers, being developed for the Integrated Program Office (IPO), that will be flown on the NASA high altitude ER-2 aircraft as part of the risk reduction effort for NPOESS. In addition to their stand-alone scientific value, data from these airborne instruments will be used to simulate possible satellite-based radiance measurements, therefore enabling experimental validation of instrument system specifications and data processing techniques for future advanced atmospheric remote sensors (e.g., the proposed sounder component for NPOESS).

The NAST-I is a high resolution Michelson interferometer, developed by MIT Lincoln Laboratory, that derives its heritage from the non-scanning High resolution Interferometer Sounder (HIS) developed by researchers at the University of Wisconsin and serves as a critical component of the NAST instrument suite. It will scan the Earth beneath the ER-2 with a nominal spatial resolution of approximately 2.5 km with 13 Earth view observations in the cross-track direction (resulting in a cross-track swath width of about 45 km), with an unapodized spectral resolution of 0.25 cm-1 within the 3.6 - 17 micron (590 - 2810 cm-1) spectral range. The NAST-I instrument flies in the superpod of NASA's high altitude ER-2 aircraft. Its infrared radiance observations will provide information on the spectral characteristics of the atmosphere and surface, enabling detailed retrievals of atmospheric temperature and water vapor profiles at high temporal and spatial resolution. Specific science products will consist of direct and derived quantities associated with the measured infrared radiance spectra. Direct products will include brightness temperatures for discrete wavelength intervals sensitive to variations in the desired geophysical parameters, i.e., surface temperature, and atmospheric temperature and water vapor. Derived products will include surface temperature, atmospheric temperature and water vapor content representative of different atmospheric vertical layers, cloud top pressure and thermodynamic state, as well as tropospheric trace gas concentrations.

NAST-I measurements obtained during the CAMEX-3 field experiment will be available from the project's data archive; most products will be in both an image format (i.e., GIF) for quick-look browsing and a digital format (i.e. NetCDF) suitable for further data analysis.