Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ESA campaign reveals glimpse of future Sentinel-3 imagery

11.09.2009
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:
http://www.esa.int
http://www.esa.int/esaEO/SEMOW432BZF_index_0.html

More articles from Physics and Astronomy:

nachricht First Juno science results supported by University of Leicester's Jupiter 'forecast'
26.05.2017 | University of Leicester

nachricht Measured for the first time: Direction of light waves changed by quantum effect
24.05.2017 | Vienna University of Technology

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: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>