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The infrared atmospheric sounding interferometer (IASI) is a Fourier transform spectrometer based on the Michelson interferometer, associated with an integrated imaging system (IIS). As part of the payload of the MetOp series of polar-orbiting meteorological satellites, there are currently two IASI instruments in operation: on MetOp-A (launched 19 October 2006) and on Met-Op B (launched 17 September 2012) with the third due for launch in 2017. IASI is a nadir-viewing instrument recording infrared emission spectra from 645 to 2760 cm−1 at 0.25 cm−1 resolution (0.5 cm−1 after apodisation). Although primarily intended to provide information in near real-time on atmospheric temperature and water vapour to support weather forecasting, the concentrations of various trace gases can also be retrieved from the spectra. == Origin and development == IASI belongs to the thermal infrared (TIR) class of spaceborne instruments, which are devoted to tropospheric remote sensing. On the operational side, it is intended as a replacement for the HIRS instruments, whereas on the scientific side, it continues the mission of instruments dedicated to atmospheric composition, which are also nadir viewing, Fourier Transform instruments (e.g. Atmospheric Chemistry Experiment). Thus, it blends the demands imposed by both meteorology - high spatial coverage, and atmospheric chemistry - accuracy and vertical information for trace gases. Designed by the Centre national d'Études Spatiales, it now combines a good horizontal coverage and a moderate spectral resolution.〔 Additionally, its counterpart on the Suomi NPP is the Cross-track infrared Sounder (CRiS). Under an agreement between CNES and EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites), the former was responsible for developing the instrument and data processing software. The latter is responsible for archiving and distributing the data to the users, as well as for operating IASI itself. Currently, Alcatel Space is the prime contractor of the project and oversees the production of the recurring models.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Infrared atmospheric sounding interferometer」の詳細全文を読む スポンサード リンク
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