The Meteosat Third Generation (MTG) Programme is a EUMETSAT geostationary satellite mission developed by the European Space Agency (ESA). It will ensure the future continuity with, and enhancement of, operational meteorological and climate data from Geostationary Orbit as currently provided by the Meteosat Second Generation (MSG) system. The MTG satellites series is composed of 4 MTG-I and 2 MTG-S to bring to the meteorological community a continuous Imagery and Sounding capabilities with high spatial, spectral, and temporal resolution observations including geophysical parameters of the Earth based on new state-of-the-art sensors.
The first satellite (MTG-I1) was launched on 13th December 2022 by an Ariane 5 rocket. It features the Flexible Combined Imager (FCI) and the Lightning Imager (LI). MTG-S series of satellites, whose first launch is planned in 2025, embarks the Infra-Red Sounder (IRS) and the Sentinel-4/ Ultra-violet/Visible/Near-Infrared (UVN) sounder instruments on geostationary orbit.
This presentation will summarise the outcomes of the Cal/Val of the MTG-I1 FCI and LI Level-1 and Level-2 operational products, and will provide the status of the MTG-S1 mission.
Accurate satellite measurements depend on rigorous radiometric performance monitoring for reliability and precision in data collection. EUMETSAT achieves this through ongoing monitoring of operational missions using vicarious calibration and inter-calibration systems.
Vicarious calibration and inter-calibration techniques employ natural targets, such as warm deserts, the Moon, Deep Convective Clouds (DCC), and dark oceans, to transfer calibration from a radiometric reference to the monitored mission. These methods are indispensable for instruments like MSG/SEVIRI, lacking an on-board calibration device for solar channels, yet widely used for monitoring and validating the radiometric performance of on-board calibration systems.
This paper presents the routine radiometric calibration monitoring of MTG-I1/FCI, MSG/SEVIRI and Sentinel-3 OLCI and SLSTR Level-1 products using our multi-mission tool, Mission Integrated Calibration Monitoring and Inter-Calibration System (MICMICS). The monitoring process encompasses diverse calibration targets, such as desert sites, DCC, lunar observations, and inter-comparisons with other reference instruments, enhancing the overall assessment.
Aboard the next generation of EUMETSAT geostationary satellites, the Flexible Combined Imager (FCI) will continue the current SEVIRI (Spinning Enhanced Visible and Infrared Imager) mission with enhanced temporal, spatial, and spectral capabilities. For monitoring the radiometric stability of the FCI reflective solar bands ranging from 0.4 to 2.2 μm, the Moon acquisitions are planned to be used. The Moon will cross the FCI field-of-view on a regular basis, under different illumination conditions and elevations. The FCI scan mechanism will allow the acquisition of the Moon with two or three consecutive swaths at the most. Two challenges must be resolved to make use of Moon observations. First, consecutive swaths include an overlap region to avoid coverage gaps. It means that some Moon areas are observed twice. Second, the swaths make an angle with respect to the equatorial plane that varies with the elevation. Consequently, it is necessary to reconstruct the full Moon disc from those consecutive swaths before the total lunar irradiance can be calculated and compared to the current lunar calibration reference, the GIRO (GSICS Implementation of the ROLO) model. This paper presents the prototype developed to make use of Moon observations with FCI. It has two components: i) a Moon transit simulator that generates equivalent Level 1b data using Himawari-8/AHI data as an input, and ii) a Moon image-stitching algorithm, which re-builds the Moon image from the simulated Level 1b swaths. In order to assess the efficiency of the stitching algorithm, two methods to reconstruct the Moon image are implemented and compared. The first one makes full use of the information available from the Moon transit simulator. The second one is the stitching method that will be deployed during operations, i.e. using exclusively information from the Level 1b swaths.
In December 2014 experts from 14 different agencies and departments attended the joint GSICS – CEOS/IVOS Lunar Calibration Workshop meeting organised by EUMETSAT in collaboration with USGS, CNES and NASA. Altogether, this represents potentially more than 25 instruments capable of observing the Moon. The main objectives of the workshop were i) to work across agencies with the GSICS Implementation of the ROLO model (GIRO) - a common and validated implementation of the USGS lunar radiometric reference, ii) to share knowledge and expertise on lunar calibration and iii) to generate for the first time a reference dataset that could be used for validation and comparisons. This lunar calibration community endorsed the GIRO to be the established publicly available reference for lunar calibration, directly traceable to the USGS ROLO model. However, further effort is required to reach inter-calibration between instruments, in particular for each instrument team to accurately estimate the over-sampling factor for their images of the Moon. A way to develop a cross-calibration algorithm and GSICS inter-calibration products is proposed. This includes key issues of fixing the GIRO calibration to an absolute scale, addressing spectral differences between instruments, and improving the existing calibration reference, which translates into future updates of the GIRO. The availability of extensive Moon observation datasets will help to further improve this reference and is expected to grow with the availability of additional lunar observations from past, current and future missions. All participants agreed on EUMETSAT pursuing its efforts in developing and maintaining the GIRO in collaboration with USGS to ensure traceability to the reference ROLO model.
Using the principle of reciprocity, observations acquired by the SEVIRI radiometer on-board the Meteosat Second
Generation satellites provide multi-angular and multi-spectral measurements that can be used for retrieving
information on both the atmospheric aerosol load, and the Earth surface. The purpose of the presented new
Land Daily Aerosol algorithm developed at EUMETSAT is to derive simultaneously the mean daily tropospheric
aerosol load and the land surface properties from the SEVIRI observations. The algorithm is based on the
Optimal Estimation theory. The aerosol load is calculated through the optical depth parameter, for various
classes of aerosols over land surfaces, and is inferred from the inversion of a forward radiative transfer model
against daily-accumulated observations in the 0.6, 0.8 and 1.6 SEVIRI bands. These daily time series provide
the angular sampling used to discriminate the radiative effects that result from the surface anisotropy, from
those caused by the aerosol scattering. Results of comparisons with AERONET data are presented to validate
the modelling approach and the algorithm that resolves the inversion problem. The retrieval error is analysed,
together with the effects on the retrieval quality of updating in time the prior information.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.