Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


ESA campaign reveals glimpse of future Sentinel-3 imagery

As part of the development process for ESA’s Sentinel-3 Earth observation mission, remote-sensing experts carried out an extensive experiment campaign across southern Europe this summer. The results provide valuable insight into the imagery the mission will deliver after it is launched in 2013.

For all new Earth observation missions, a crucial part of the development process, after defining and designing the instruments, is to assess the future performance of the sensors. In addition, the algorithms being developed to transform the satellite data into usable information products also have to be tested.

In order to make these assessments, ESA organises test campaigns using airborne instruments that closely match the characteristics of the spaceborne sensors. The effort is coordinated with ground-based teams that collect complementary scientific data for calibration and evaluation.

One such campaign was recently completed for Sentinel-3, which is the third in a series of five space missions ESA is developing for the Global Monitoring for Environment and Security (GMES) initiative. Led by the European Commission, GMES will fulfil the growing need among European policy-makers to access accurate and timely information services to manage the environment, understand and mitigate the effects of climate change, and ensure civil security.

The ‘Sentinel-3 Experiment’ campaign – or Sen3Exp for short – involved a series of coordinated activities with scientists making ground-based measurements in Spain, Italy and the Ligurian and Adriatic Seas, while aircraft with sensitive instrumentation passed overhead and satellites acquired data simultaneously from space. The result is a comprehensive dataset of imagery and ground-truth information that can be used to simulate Sentinel-3 optical data, test the processors under development to generate the data products, and analyse whether these data products will satisfy the requirements of the user communities.

The campaign's Principal Investigator, Dr Carsten Brockmann, confirmed that, “A unique, comprehensive and valuable dataset has been created that will significantly support the development of the Sentinel-3 mission.”

Primarily, Sentinel-3 will support services related to the marine environment, such as maritime safety services that need ocean surface-wave information, ocean-current forecasting services that need surface-temperature information, and sea-water quality and pollution monitoring services that require advanced ocean colour products from both the open ocean and coastal areas. Sentinel-3 will also serve numerous land, atmospheric and cryospheric application areas such as land-use change monitoring, forest cover mapping and fire detection.

The mission's complement of optical sensors will comprise an Ocean Land Colour Instrument (OLCI), which is based on Envisat’s Medium Resolution Imaging Spectrometer (MERIS), and a Sea Land Surface Temperature Radiometer (SLSTR), which is a successor to Envisat’s Advanced Along Track Scanning Radiometer (AATSR).

The Sen3Exp campaign began in June in Barrax, La Mancha, Spain. An aircraft operated by the Spanish National Institute for Aerospace Technology (INTA), equipped with three hyperspectral imaging spectrometers, made two flights over the area. Meanwhile, satellite data were acquired by Envisat’s MERIS and AATSR and by the Compact High Resolution Imaging Spectrometer (CHRIS) aboard ESA’s Proba-1 satellite. At the same time, ground teams, under the direction of Prof. Jose Moreno from the University of Valencia, made atmospheric radiometric and biophysical measurements.

The campaign then moved to Pisa in Italy, from where a pine forest at San Rossore could be reached. At San Rossore, Prof. Federico Magnani from the University of Bologna oversaw the week-long ground measurement programme. The dataset was again complemented with MERIS, AATSR and CHRIS satellite data.

In July, activities focused on the marine environment where measurements were taken at two oceanic sites: the Boussole monitoring buoy in the Ligurian Sea and the Aqua Alta Oceanographic Tower (AAOT) in the Adriatic Sea, close to Venice. Both sites have played an important role in supporting ocean colour algorithm development and product validation for many years.

Boussole typifies the global ocean, where the measured signal is determined solely by the absorption of phytoplankton. AAOT is in an area where there is both open ocean water and also water that is optically complex because phytoplankton, suspended sediments and coloured dissolved organic matter also affect the measured signal. Such water can be found in all coastal regions and is a challenge to understand from space.
Routine radiometry measurements are made at these locations, both above and below the water surface and fed into the Mermaid database, managed by ARGANS, UK. A unique flight pattern was developed by the Sen3Exp team that encompassed a wide range of observational configurations. Two overpasses over each site were carried out and an image over the coast that included the transition between land and ocean was also acquired, which will be important for understanding how the signal behaves in coastal zones.

The campaign also took advantage of the fact that the MERIS 15 spectral bands can be reprogrammed. Thus, for several short periods during the campaign window, data were acquired using some of the new spectral bands planned for OLCI and provided some of the most realistic simulations possible of the data expected from Sentinel-3.
With more than 60 people involved, the success of this technically and logistically complex campaign demonstrates the excellent cooperation between European scientists. Now comes the task of analysing the huge dataset collected during the campaign. An additional opportunity for data analysis is provided by the inclusion in of data collected from the Airborne Prism Experiment (APEX) imaging spectrometer during a parallel campaign in Switzerland and Belgium.

In the meantime, Professors Moreno and Magnani agree that, “A large data archive has been generated that will help not only to provide important input for Sentinel-3 but will be valuable for future ESA missions.”

Mariangela D'Acunto | EurekAlert!
Further information:

More articles from Physics and Astronomy:

nachricht Laser-wielding physicists seize control of atoms' behavior
06.10.2015 | University of Chicago

nachricht Observing the Unobservable: Researchers Measure Electron Orbitals of Molecules in 3D
05.10.2015 | Karl-Franzens-Universität Graz

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Physicists shrink particle accelerator

Prototype demonstrates feasibility of building terahertz accelerators

An interdisciplinary team of researchers has built the first prototype of a miniature particle accelerator that uses terahertz radiation instead of radio...

Im Focus: Simple detection of magnetic skyrmions

New physical effect: researchers discover a change of electrical resistance in magnetic whirls

At present, tiny magnetic whirls – so called skyrmions – are discussed as promising candidates for bits in future robust and compact data storage devices. At...

Im Focus: High-speed march through a layer of graphene

In cooperation with the Center for Nano-Optics of Georgia State University in Atlanta (USA), scientists of the Laboratory for Attosecond Physics of the Max Planck Institute of Quantum Optics and the Ludwig-Maximilians-Universität have made simulations of the processes that happen when a layer of carbon atoms is irradiated with strong laser light.

Electrons hit by strong laser pulses change their location on ultrashort timescales, i.e. within a couple of attoseconds (1 as = 10 to the minus 18 sec). In...

Im Focus: Battery Production: Laser Light instead of Oven-Drying and Vacuum Technology

At the exhibition BATTERY + STORAGE as part of WORLD OF ENERGY SOLUTIONS 2015 in Stuttgart, the Fraunhofer Institutes for Laser Technology ILT and for Ceramic Technologies and Systems IKTS will be showing how laser technology can be used to manufacture batteries both cost- and energy-efficiently.

In the truest sense, it’s all about watts at the Dresden-based Fraunhofer Institute for Ceramic Technologies and Systems IKTS and the Aachen-based Fraunhofer...

Im Focus: New Sinumerik features improve productivity and precision

EMO 2015, Hall 3, Booth E06/F03

  • Drive optimization called automatically by the part program boosts productivity
  • Automatically switching the dynamic values to rapid traverse and interpolation...
All Focus news of the innovation-report >>>



Event News

EHFG 2015: Securing healthcare and sustainably strengthening healthcare systems

01.10.2015 | Event News

Conference in Brussels: Tracking and Tracing the Smallest Marine Life Forms

30.09.2015 | Event News

World Alzheimer`s Day – Professor Willnow: Clearer Insights into the Development of the Disease

17.09.2015 | Event News

Latest News

Graphene teams up with two-dimensional crystals for faster data communications

06.10.2015 | Information Technology

Laser-wielding physicists seize control of atoms' behavior

06.10.2015 | Physics and Astronomy

Flipping molecular attachments amps up activity of CO2 catalyst

06.10.2015 | Life Sciences

More VideoLinks >>>