. Atmospheric remote sounding from satellites is an essential component of the observational strategy deployed to monitor atmospheric pollution and changing composition. The IASI nadir looking thermal infrared sounder onboard MetOp will provide 15 years of global scale observations for a series of key atmospheric species, with unprecedented spatial sampling and coverage. This paper gives an overview of the instrument's capability for measuring atmospheric composition in the perspective of chemistry and air quality. The assessment is made in terms of species, accuracy and vertical information. Global distributions are presented for CO, CH4, O3 (total and tropospheric), HNO3, NH3, and volcanic SO2. Local distributions of organic species measured during fire events, such as C2H4, CH3OH, HCOOH, and PAN are also shown. For each species or process, the link is made to specialized papers in this issue.

/pdf/monitoring-of-atmospheric-composition-using-the-thermal-2ktxqf7uy7.pdf

Monitoring of atmospheric composition using the thermal infrared IASI/METOP sounder

Abstract. Atmospheric remote sounding from satellites is an essential component of the observational strategy deployed to monitor atmospheric pollution and changing composition. The IASI nadir looking thermal infrared sounder onboard MetOp will provide 15 years of global scale observations for a series of key atmospheric species, with unprecedented spatial sampling and coverage. This paper gives an overview of the instrument's capability for measuring atmospheric composition in the perspective of chemistry and air quality. The assessment is made in terms of species, accuracy and vertical information. Global distributions are presented for CO, CH4, O3 (total and tropospheric), HNO3, NH3, and volcanic SO2. Local distributions of organic species measured during fire events, such as C2H4, CH3OH, HCOOH, and PAN are also shown. For each species or process, the link is made to specialized papers in this issue.

http://systemarchitect.mit.edu/docs/selva12b.pdf

A survey and assessment of the capabilities of Cubesats for Earth observation

Four years after launch, IASI has delivered significant advances in remote sensing capability for numerical weather prediction and atmospheric composition monitoring and promises an excellent dataset for climate studies. The Infrared Atmospheric Sounding Interferometer (IASI) forms the main infrared sounding component of EUMETSAT's Metop-A satellite (Klaes et al., 2007), which was launched in October 2006. This article presents the results of the first four years of the operational IASI mission. The performance of the instrument is shown to be exceptional in terms of calibration and stability the quality of the data has allowed the rapid use of the observations in operational numerical weather prediction (NWP) and the development of new products for atmospheric chemistry and climate studies, some of which were unexpected before launch. The assimilation of IASI observations in NWP models provides significant forecast impact; in most cases the impact has been shown to be at least as large as for any previous instrument. In atmospheric chemistry, global distributions of gases such as ozone and carbon monoxide can be produced in near-real time, and short-lived species such as ammonia or methanol can be mapped, allowing identification of new sources. The data have also shown the ability to track the location and chemistry of gaseous plumes and particles associated with volcanic eruptions and fires, providing valuable data for air quality monitoring and aircraft safety. IASI also contributes to the establishment of robust long term data records of several essential climate variables. The suite of products being developed from IASI continues to expand as the data are investigated, and further impacts are expected from increased use of the data in NWP and climate studies in the coming years. The instrument has set a high standard for future operational hyperspectral infrared sounders, and demonstrated that such instruments have a vital role in the global observing system.

/pdf/hyperspectral-earth-observation-from-iasi-five-years-of-3bq6uzno65.pdf

Hyperspectral Earth Observation from IASI: Five Years of Accomplishments

Requirements for the GMES Atmosphere Service and ESA's implementation concept: Sentinels-4/-5 and -5p

The Infrared Atmospheric Sounding Interferometer (IASI) is a key payload element of the METOP series of European meteorological polar-orbit satellites. IASI will provide very accurate data about the atmosphere, land and oceans for application to weather predictions and climate studies. The IASI measurement technique is based on passive IR remote sensing using an accurately calibrated Fourier Transform Spectrometer operating in the 3.7 - 15.5 μm spectral range and an associated infrared imager operating in the 10.3-12.5 μm spectral range. The optical configuration of the sounder is based on a Michelson interferometer. Interferograms are processed by the on-board digital processing subsystem which performs the inverse Fourier Transform and the radiometric calibration. The integrated infrared imager allows the co registration of the IASI sounder with AVHRR imager on-board METOP.
The first model (proto-flight) of IASI has successfully completed a verification program conducted at ALCATEL SPACE premises in Cannes. This paper provides a brief overview of the IASI mission, instrument architecture and key performances results. A companion paper1 by Alcatel provides more information on instrument design and development.

IASI instrument: technical overview and measured performances

The purpose of this paper is to present the IASI overall architecture and the IASI functional chain including optics and interferometer, analogue to digital acquisition, on board and on ground digital processing. It points out special features of IASI's design and critical technologies. The IASI technical description is followed by a development status including activities on breadboards, engineering models, proto flight and flight models with emphasis put on achieved critical steps. A companion paper by CNES will provide detailed information on the IASI mission and instrument key performance achievement.

Thierry Maciaszek

Papers

IASI instrument: technical overview and measured performances

Design and development of IASI instrument