NPOESS Airborne Sounder Testbed (NAST) Infrared Interferometer Sounder (NAST-I) 3.5 – 16 micron @ 0.25 cm-1 NADIR 2.6 km IFOV 20 km Altitude +/- 23 km Ground Coverage Electronics, Control, Navigation, Processing, Recording Microwave Radiometers (NAST-M) 54, 118 GHz* NASA ER-2 [*183 & 425 GHz expected before IHOP-02] Support NPOESS Sounding Instrument Development &Validation (CrIS & ATMS) Provide Mesoscale Earth Science Observations (from field experiment campaigns, e.g. CAMEX-3, WINTEX, CART site IOPs, and other flights of opportunity, e.g. Wallops98/99) Serve as an EOS Validation Tool (AIRS, CERES, MODIS, MOPITT,TES) Serve as an engineering testbed (infuse new technology to explore: enhancing airborne sounding; optimizing space-based sounding performance; and other measurements, e.g. GEO sounding & chemistry)

Far Infrared Sensor for Cirrus (FIRSC) A Powerful New Technique for Characterizing Cirrus Properties Far IR Radiance Spectrum of Cirrus (Ice) Clouds Polarizing Fourier Transform Spectrometer Results Validate Theory showing Large “Mie” Scattering Cirrus Signatures in the FIR Enables Measurement of Cirrus IWP, Size, and Shape for Climate Modeling Team Members: NASA Langley Research Center Queen Mary and Westfield College, London University of Colorado University of Oregon British Meteorological Office Flight International, Inc.

Potential Proteus Payload Primary Data Products Direct Products calibrated radiances (IR, Far-IR, & U-wave) Derived Products atmospheric temperature profiles atmospheric water vapor profiles surface temperature & emissivity cloud properties (altitude, temp. & emiss., IWP/LWP, particle size) tropospheric species column concentrations & some profiling (e.g. ozone, carbon monoxide) atmospheric transport via H2O winds aerosol IR optical depth

Potential NAST/Proteus IHOP Flight Objectives Overflight, mapping, and vertical radiance profiling over DOE ARM CART ground-based facilities, spatially & temporally coincident with other independent observations Tropospheric thermal and H2O spatial & temporal field characterization Validation intercomparisons with other independent ground-, balloon-, aircraft-, and space-based observations (in-situ & passive/active remote) IR radiance measurement & forward model validation geophysical parameter retrieval algorithm validation synergistic retrieval studies (e.g., NAST-I + NAST-M, +FIRSC, + LASE, etc.) Advanced LEO & GEO sensor parameter estimation studies Secondary cloud & precipitation overflight interests NAST-M measurements over precipitation, preferably varying intensity & type (i.e. solid/liquid) coincident with NEXRAD observations NAST-I/FIRSC coincident measurements over varying optical depth cirrus (e.g. perpendicular to frontal boundaries) preferably over CART site central facility radar

Summary NAST provides high spatial/spectral/temporal resolution radiance measurements for observing atmospheric temperature, moisture, and clouds NAST sounding data over the DoE ARM-site can be used to account for time and space variability when comparing and interpreting other measurements (e.g., ground-, balloon-, aircraft-, and space-based systems) Measured profiles of NAST radiances can be used to validate forward radiative transfer models and provide high vertical resolution profiles of atmospheric temperature and absorbing constituent profiles needed to validate aircraft and satellite retrievals The NAST/Proteus team has participated in 3 recent experiments at the SGP CART site (i.e., CIOP, WVIOP, & AFWEX), the last 2 focusing on water vapor characterization NAST IHOP in-field participation support will be pursued through the NPOESS IPO; additional funding needed to enable data analysis and IHOP-unique activities studies/activities.