Balloonborne calibrated spectroradiometer for atmospheric nadir sounding

Laboratoire de Physique Moleculaire et Applications (LPMA)/Infrared Atmospheric Sounding interferometer (IASI) balloon is a calibrated infrared Fourier transform spectrometer that is used to measure the Earth's atmospheric emission (650-3000 cm(-1)). Operating under a stratospheric balloon, this spectroradiometer provides radiometrically calibrated spectra with an apodized spectral resolution of 0.1 cm(-1), which can be used to retrieve the concentration of atmospheric trace gases such as H2O, CO2, CO, O-3, N2O, and CH4. The radiometric calibration is performed by use of two reference blackbodies. A reference cavity (LPMA blackbody) has been developed to validate the radiometric calibration procedure and to characterize the instrument performances. One goal of the LPMA/IASI balloon is the preparation of the IASI mission, which is a satellite instrument dedicated primarily to operational meteorology. A description of the LPMA/IASI balloon, its performances, and the results obtained during the first flight of the instrument are presented. (C) 2002 Optical Society of America.