Infrared Atmospheric Sounding Interferometer

Infrared Atmospheric Sounding Interferometer
Name	Infrared Atmospheric Sounding Interferometer

Infrared Atmospheric Sounding Interferometer is a series of spaceborne Fourier transform spectrometer instruments flown on polar-orbiting meteorological satellites to measure Earth's atmospheric temperature and composition, supporting weather prediction and climate monitoring. The instrument program integrates technology and operations from organizations such as European Space Agency, EUMETSAT, European Organisation for the Exploitation of Meteorological Satellites, Met Office, and collaborations with agencies like NOAA, NASA, CNES, and JAXA. Data from the instruments are assimilated by centers including ECMWF, UK Met Office, US National Centers for Environmental Prediction, and used in research by institutions such as Max Planck Institute for Meteorology, NCAR, and Scripps Institution of Oceanography.

Overview

The program was developed within a context linking industrial partners like Airbus Defence and Space, Thales Alenia Space, and scientific laboratories including Rutherford Appleton Laboratory, Institut d'Astrophysique Spatiale, and Laboratoire de Météorologie Dynamique to provide high-spectral-resolution infrared sounding for satellites such as MetOp series, Metop-A, Metop-B, and Metop-C. The instrument complements sensors aboard platforms like NOAA-19, Suomi NPP, JPSS and missions including ERBS, Aqua, and Terra by filling spectral and temporal niches exploited by centers like ECMWF and research groups at University of Oxford and Massachusetts Institute of Technology.

Instrument Design and Operation

The instrument is a Michelson-style Fourier transform spectrometer assembled with components sourced from suppliers and labs linked to CNES, DLR, and ESA technology programs, integrating cryogenic detectors, beam-splitters, and scanning mechanisms developed with expertise from Fraunhofer Society, CEA Saclay, and Rutherford Appleton Laboratory. It obtains spectra across mid- and far-infrared bands to sense radiances associated with gases such as Water vapor, Carbon dioxide, Ozone, and trace species, supporting retrievals used by groups at University of Cambridge, University of Reading, and University of Tokyo. The instrument's optical bench, servo systems, and electronics were qualified using facilities at ESTEC, IABG, and DLR Oberpfaffenhofen, while integration and testing involved teams from EUMETSAT and national meteorological services such as Météo-France and Met Éireann.

Calibration and Data Processing

Radiometric and spectral calibration pipelines rely on blackbody references and internal calibration sources whose characterization involved laboratories such as NPL (United Kingdom), PTB, and cryogenic facilities at Institut d'Astrophysique Spatiale. Level-0 to Level-2 processing chains have been developed jointly by entities including EUMETSAT, NOAA, ECMWF, and contractor teams from Serco Group and CGI Group Inc., producing radiance, brightness temperature, and geophysical retrieval products used by research centers such as University of Colorado Boulder and Chinese Academy of Sciences. Algorithms implement Fourier transform operations, apodization, and instrument line shape corrections informed by studies at Imperial College London, NASA Langley Research Center, and Jet Propulsion Laboratory.

Mission History and Deployments

The instrument series has flown on successive meteorological platforms, integrated into programs coordinated by ESA and EUMETSAT, with launch campaigns involving contractors like Arianespace and ground segment operations by EUMETSAT and national agencies such as Met Office and KNMI. Mission timelines intersect with milestones at NOAA and climate monitoring initiatives including Global Climate Observing System and World Meteorological Organization activities, while cross-calibration exercises have engaged satellite teams from JAXA, NASA, and ISRO. Deployments have supported operational forecasting centers including ECMWF, US NCEP, and regional services such as Japan Meteorological Agency.

Scientific Applications and Products

Products derived from the instrument feed numerical weather prediction and climate diagnostics used by ECMWF, UK Met Office, NOAA NCEI, and academic groups at Harvard University, Princeton University, and ETH Zurich. Applications include temperature and humidity profile retrievals, trace gas column retrievals for Carbon dioxide and Ozone, surface and atmospheric sounding for assimilation by centers like Met Office, as well as climate trend analyses by organizations such as IPCC contributors and research groups at Lamont–Doherty Earth Observatory and Potsdam Institute for Climate Impact Research. Data support studies of phenomena linked to El Niño–Southern Oscillation, Arctic amplification, Antarctic ozone hole, and other climate-relevant events examined by institutions including NOAA PSL and University of Alaska Fairbanks.

Performance and Validation

Performance assessment and validation campaigns have been conducted with airborne instruments from programs at NASA Ames Research Center, NCAR, and DLR, and in situ networks including AGAGE, NDACC, and radiosonde networks operated by national meteorological services such as Météo-France and Deutscher Wetterdienst. Intercomparisons with instruments on Aqua and Terra, lidar networks at NOAA, and microwave sounders operated by EUMETSAT and NESDIS inform bias corrections and uncertainty estimates used in assimilation at ECMWF and validation studies by University of Reading and University of Hamburg. Continuous monitoring by teams at EUMETSAT and partners such as UK Met Office ensures operational readiness and product quality for forecasting and climate research.

Category:Remote sensing instruments