Cloud and precipitation observations with the NPOESS Aircraft Sounder Testbed-Microwave (NAST-M) spectrometer suite at 54/118/183/425 GHz

The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Aircraft Sounder Testbed-Microwave, or NAST-M, has added two spectrometers to its original suite operating near the oxygen lines at 50-57 GHz and the oxygen line at 118.75 GHz. These new spectrometers are centered on the water vapor absorption line at 183.31 GHz and the oxygen absorption line at 424.76 GHz. This addition has increased the ability of NAST-M to retrieve humidity profiles and to sense smaller-diameter hydrometeors. The co-aligned NAST-M suite concurrently imaged clouds and convective cells during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE 2002) and the 2003 Pacific THORpex (The Observing-system Research and predictability experiment) Observing System Test (THORpex 2003).