The calibration/validation phase is now underway to precisely calibrate the instrument and refine processing parameters to obtain perfectly calibrated atmospheric spectra for operational distribution to users in 2026. These data are eagerly awaited by the international scientific community and national weather services.
Metop-SGA1 was developed by the European Space Agency (ESA) on EUMETSAT’s behalf and is operated by EUMETSAT. At the end of the in-orbit commissioning phase, EUMETSAT will take over management of operational data for all instruments on the satellite. CNES has overall technical responsibility for IASI-NG, including during in-orbit commissioning, with support from the French national scientific research centre CNRS and national weather service Meteo-France. CNES also developed part of the EUMETSAT processing chain that turns raw acquisitions from the instrument into atmospheric characterization data, and is in charge of developing and operating a technical expertise centre to monitor the instrument’s performance in orbit. The instrument was built for CNES by Airbus Defence & Space, working from instrument specifications and science goals established by the scientific community.
IASI-NG is designed to observe Earth’s atmosphere for meteorology, climate science and air quality monitoring. It succeeds the IASI instruments operating on the first generation of Metop satellites since 2006. It is set to improve performance by a factor of two and will sound the atmosphere with unprecedented precision, measuring temperature, humidity and atmospheric composition (ozone, methane, carbon dioxide, aerosols, etc.) continuously over a period of 20 years, thus making a significant contribution to the monitoring of Earth’s climate. CNRS research laboratories are closely involved in processing IASI-NG spectra to extract the geophysical and climate data required to characterize and monitor the planet’s atmosphere.
The first data from the IASI-NG instrument were generated from raw measurements processed with system settings defined during ground testing. This first spectrum shows the composition of the atmosphere seen by the instrument as the satellite was flying over Toulouse, France.
IASI-NG splits light waves reflected from Earth according to their frequency. Snapshots of the atmosphere are obtained from 16,921 separate data points (spectral channels), each of which can be selected and compared to any other point on the globe. This atmospheric spectrum represents the amount of energy measured as a function of light wave frequency in IASI-NG’s infrared range. Providing much greater detail than its predecessor, the instrument is able to identify the characteristic signatures of molecules in the atmosphere. These initial spectra acquired on 30 September already give a glimpse of the broad variety of chemical species that IASI-NG can sense, such as carbon dioxide, nitric acid, methane or ozone.
The instrument observes radiation from Earth, and the spectral lines it sees show light absorbed by the different molecules in the atmosphere at that particular time. The depth of these lines tells us how many molecules are present, while the sharper resolution allows us to determine this information with greater accuracy at different altitudes.
The first data also include information acquired by IASI-NG’s imager, which operates in an infrared channel and enables exact co-registration of sounding points with images. All data are acquired by scanning left to right along the satellite’s track.
The IASI-NG instrument’s improved performance is made possible by an innovative Mertz interferometer* concept, deployed for the first time on a space mission. Its measurements will enable extraction of more accurate vertical profiles of temperature and humidity close to the surface, a key requirement for further improving global and regional numerical prediction models.
The IASI-NG mission is a key element of international climate science efforts. Its improved performance will deliver more data on greenhouse gases and deeper insights into the chemical components in the atmosphere to better estimate air quality.
The IASI-NG mission is expected to continue acquiring data until at least 2047 and possibly beyond. Added to the dataset built up by the previous generation of IASI instruments, these data will provide an unprecedented climate record covering more than 40 years of global atmospheric observations.
For more information, see the
EUMETSAT website.
* The Mertz principle is based on a Michelson interferometer that compensates for field effects by inserting in the optical path a plate whose thickness is controlled to provide the right optical index.
About EUMETSAT
EUMETSAT, Europe’s meteorological satellite agency, monitors the weather and climate from space. Based in Darmstadt, Germany, it provides its 30 member states with meteorological imagery and data that are essential for the safety of their communities and key sectors of their economies. Four Meteosat satellites in geostationary orbit deliver continuous observations of fast-developing severe weather events, while two polar-orbiting Metop satellites provide data of pivotal importance for forecasts from one to ten days in advance. EUMETSAT operates the Sentinel ocean- and atmosphere-monitoring missions for the EU’s Copernicus programme, and is also a partner in the Jason ocean-monitoring mission.
About CNES
CNES (Centre National d’Etudes Spatiales) is the government agency responsible for shaping France’s space policy and implementing it in Europe. Its task is to conceive and orbit satellites, invent the space systems of the future and nurture new services to aid us in our daily lives. Founded in 1961, it is the initiator of major space projects, launch vehicles and satellites, and the partner of choice for industry, fuelling innovation. CNES comprises some 2,400 men and women with a passion for space working in infinite fields of applications in five core areas of focus: Ariane, science, Earth observation, telecommunications and defence. It is a key player driving technology innovation, economic development and industrial policy for the nation. It also fosters scientific collaborations and has forged numerous international partnerships. France, represented by CNES, is a leading contributor to the European Space Agency (ESA).
About CNRS
A leading world player in fundamental research, the National Centre for Scientific Research (CNRS) is the only French organization active in all fields of science. Its unique position as a multi-specialist enables it to combine all scientific disciplines to shed light on and understand the challenges of today's world, working with public and socio-economic stakeholders. Together, sciences are serving sustainable progress that benefits society as a whole.
About Meteo-France
Meteo-France is the national weather and climate service tasked with forecasting weather, preserving the climate record and studying future climate. By anticipating weather conditions at ever finer temporal and spatial scales, it helps to keep people, property and the economy safe. To this end, it alerts authorities and citizens to weather-related risks and provides its expertise to government departments. Meteo-France also analyses how climate is evolving and helps to predict the impacts of global and local climate change thanks to some of the most sophisticated climate models in the world.
In economic and social sectors increasingly prone to weather and climate risks, Meteo-France delivers weather and climate services to help authorities and businesses take better decisions and tailor their adaptation strategies.