Global Monitoring for Environment and Security (GMES) is the European programme to establish a European capacity for Earth Observation. GMES is designed to provide European policy makers and public ...authorities with accurate and timely information to better manage the environment, understand and mitigate the effects of climate change and ensure civil security. Sentinel-3 is an Earth observation satellite mission specifically designed for GMES to ensure the long-term collection and operational delivery of high-quality measurements to GMES ocean, land, and atmospheric services, while contributing to the GMES, emergency and security services. Key Sentinel-3 measurement requirements, corresponding to identified GMES user needs, have been derived as follows:•Sea surface topography (SSH), significant wave height (Hs) and surface wind speed derived over the global ocean to an equivalent accuracy and precision as that presently achieved by ENVISAT Radar Altimeter-2 (RA-2) but with enhanced surface topography measurements in the coastal zone, sea ice regions and over inland rivers, their tributaries and lakes.•Sea surface temperature (SST) determined for oceanic and coastal waters globally to an equivalent accuracy and precision as that presently achieved by the ENVISAT Advanced Along Track Scanning Radiometer (AATSR) over the ocean (i.e. <0.3K), at a spatial resolution of 1km.•Visible, and Short-Wave Infrared radiances for oceanic, inland and coastal waters at a spatial resolution of 0.3km (simultaneously and co-registered with SST measurements), determined to an equivalent level of accuracy and precision as ENVISAT Medium Resolution Imaging Spectrometer with complete ocean coverage in 2–3days.•Visible and infrared radiances over global land-surfaces in 1–2days, sea-ice and ice-sheets equivalent to those currently provided from ENVISAT MERIS, AATSR and Système Probatoire d'Observation de la Terre (SPOT) Vegetation.
The Sentinel-3 mission addresses these requirements by implementing and operating:•A dual frequency, Synthetic Aperture Radar Altimeter (SRAL) instrument supported by a dual frequency passive microwave radiometer (MWR) for wet-tropospheric correction, a Precise Orbit Determination package including a GPS receiver, a DORIS instrument and a laser retro-reflector.•A highly sensitive Ocean and Land Colour Imager (OLCI) delivering multi-channel wide-swath optical measurements for ocean and land surfaces.•A dual-view Sea and Land Surface Temperature Radiometer (SLSTR) delivering accurate surface ocean, land, and ice temperature.•A collaborative ground segment providing management of the mission, management, development, production and access to core data products in an operational near real time delivery context.
The mission foresees a series of satellites, each having 7-year lifetime, over a 20-year period starting with the launch of Sentinel-3A in late 2013 and of Sentinel-3B in late 2014. During full operations two identical satellites will be maintained in the same orbit with a phase delay of 180°.
This paper provides an overview of the GMES Sentinel-3 mission including the mission background and user requirements, a technical description of the space segment, a brief overview of the ground segment concept, and a summary description of Sentinel-3 data products and their anticipated performance.
► A new satellite mission called Sentinel-3 dedicated to oceanography is described. ► A technical overview of the Sentinel-3 instrument payload is presented. ► A summary of the Sentinel-3 ground segment and operations concept is presented. ► A summary of products derived from Sentinel-3 payload instruments is presented.
Agricultural intensification and associated loss of high‐quality habitats are key drivers of insect pollinator declines. With the aim of decreasing the environmental impact of agriculture, the 2014 ...EU Common Agricultural Policy (CAP) defined a set of habitat and landscape features (Ecological Focus Areas: EFAs) farmers could select from as a requirement to receive basic farm payments. To inform the post‐2020 CAP, we performed a European‐scale evaluation to determine how different EFA options vary in their potential to support insect pollinators under standard and pollinator‐friendly management, as well as the extent of farmer uptake.
A structured Delphi elicitation process engaged 22 experts from 18 European countries to evaluate EFAs options. By considering life cycle requirements of key pollinating taxa (i.e. bumble bees, solitary bees and hoverflies), each option was evaluated for its potential to provide forage, bee nesting sites and hoverfly larval resources.
EFA options varied substantially in the resources they were perceived to provide and their effectiveness varied geographically and temporally. For example, field margins provide relatively good forage throughout the season in Southern and Eastern Europe but lacked early‐season forage in Northern and Western Europe. Under standard management, no single EFA option achieved high scores across resource categories and a scarcity of late season forage was perceived.
Experts identified substantial opportunities to improve habitat quality by adopting pollinator‐friendly management. Improving management alone was, however, unlikely to ensure that all pollinator resource requirements were met. Our analyses suggest that a combination of poor management, differences in the inherent pollinator habitat quality and uptake bias towards catch crops and nitrogen‐fixing crops severely limit the potential of EFAs to support pollinators in European agricultural landscapes.
Policy Implications. To conserve pollinators and help protect pollination services, our expert elicitation highlights the need to create a variety of interconnected, well‐managed habitats that complement each other in the resources they offer. To achieve this the Common Agricultural Policy post‐2020 should take a holistic view to implementation that integrates the different delivery vehicles aimed at protecting biodiversity (e.g. enhanced conditionality, eco‐schemes and agri‐environment and climate measures). To improve habitat quality we recommend an effective monitoring framework with target‐orientated indicators and to facilitate the spatial targeting of options collaboration between land managers should be incentivised.
Resumen
La intensificación agrícola y la consecuente pérdida de hábitats de alta calidad son desencadenantes clave del declive de los insectos polinizadores. Con el objetivo de disminuir el impacto ambiental de la agricultura, la Política Agrícola Común (PAC) de la UE de 2014 definió un conjunto de medidas para hábitats y paisajes (Áreas de Enfoque Ecológico: EFA por sus siglas en inglés) que los agricultores podían seleccionar como requisito para recibir pagos agrícolas básicos. Para informar la reforma de la PAC a partir a 2020, realizamos una evaluación a escala europea para determinar cómo las diferentes opciones de EFA varían en su potencial para asistir a los insectos polinizadores bajo un manejo estándar y amigable con los polinizadores, así como su aceptación por parte de los agricultores.
El proceso estructurado de elicitación Delphi para evaluar las opciones de EFA involucró a 22 expertos de 18 países europeos. Se consideraron los requisitos de los diferentes taxones de polinizadores (es decir, abejorros, abejas solitarias y sírfidos) evaluando cada opción por su potencial para proporcionar forraje, sitios de nidificación y recursos para las larvas.
Las opciones de EFA variaron sustancialmente en la cantidad de recursos que se percibía que proporcionan y su efectividad vario geográfica y temporalmente. Por ejemplo, los márgenes de cultivos proporcionan un forraje relativamente bueno durante toda la temporada en el sur y el este de Europa, pero carecen de forraje a principios de temporada en el norte y oeste de Europa. Bajo el manejo estándar, ninguna opción de EFA logró puntuaciones altas en todas las categorías de recursos y en general se percibió una escasez de forraje al final de la temporada.
Los expertos identificaron oportunidades sustanciales para mejorar la calidad del hábitat mediante la adopción de un manejo amigable con los polinizadores. Sin embargo, mejorar la gestión por sí solo es poco probable que garantice que se cumplan todos los requisitos necesarios para los polinizadores. Nuestro análisis sugiere que una combinación de manejo inadecuado, diferencias de calidad inherentes a los distintos hábitat y el sesgo de aceptación hacia cultivos de cobertura y cultivos que fijan nitrógeno limitan severamente el potencial de los EFA para apoyar a los polinizadores en los paisajes agrícolas europeos.
Implicaciones políticas. Para conservar a los polinizadores y ayudar a proteger los servicios de polinización, nuestro estudio destaca la necesidad de crear una variedad de hábitats interconectados y bien administrados que se complementen entre sí en los recursos que ofrecen. Para lograr esto, la PAC post‐2020 debe integrar los diferentes vehículos de implementación destinados a proteger la biodiversidad (por ejemplo, condicionalidad mejorada, esquemas ecológicos y medidas agroambientales y climáticas). Para mejorar la calidad del hábitat, recomendamos un marco de monitoreo efectivo con indicadores orientados a objetivos y incentivar la colaboración entre los administradores de las tierras.
Résumé
L’intensification agricole et la perte associée d'habitats semi‐naturels sont les principaux moteurs du déclin des insectes pollinisateurs. Dans l'intention de réduire l'impact environnemental de l'agriculture, la politique agricole commune (PAC) de l'UE de 2014 a défini un ensemble d'habitats et d’éléments paysagers (surfaces d'intérêt écologique: SIE) dans la mise en place ou le respect desquels les agriculteurs pouvaient s'engager comme condition pour bénéficier d'aides économiques européennes (droit au paiement de base). Pour éclairer la PAC post‐2020, nous avons évalué à l'échelle européenne et à dire d'expert, d'une part les potentialités des diverses SIE à favoriser les insectes pollinisateurs, via une gestion standard et via une gestion optimisée, et d'autre part l'étendue de l'adoption de ces mesures par les agriculteurs.
Un processus structuré d’élaboration et d'agrégation des opinions (méthode Delphi) a fait appel à 22 experts de 18 pays européens pour évaluer les potentialités des diverses SIE. Considérant les traits bioécologiques des principaux taxons pollinisateurs (i.e. bourdons, abeilles solitaires et syrphes), chaque SIE a été évaluée pour son potentiel à fournir des ressources trophiques et des sites de reproduction (sites de nidification pour les bourdons et abeilles, sites de ponte et développement larvaire pour les syrphes).
Les SIE différaient considérablement les unes des autres sur les ressources qu'elles étaient censées offrir et leur efficacité variait géographiquement et temporellement. Par exemple, les bords de champ peuvent fournir des ressources trophiques tout au long de l'année en Europe du Sud et de l'Est mais pas en début de saison en Europe du Nord et de l'Ouest. En cas de gestion standard, aucun type de SIE n'atteint de score élevé pour aucun type de ressource, et une période de disette alimentaire survient en fin de saison.
Les experts ont mis en évidence de possibles et substantielles améliorations des SIE par le biais de leur gestion optimisée. Cependant, cette seule amélioration ne garantit pas la fourniture de ressources suffisantes aux pollinisateurs des paysages agricoles européens. Pour cela, des habitats spécifiques doivent être favorisés, dont la mise en place ne doit pas être entravée par un choix massif de SIE à base de cultures intermédiaires pièges à nitrates ou fixatrices d'azote.
Implications politiques. Pour préserver les pollinisateurs et le service de pollinisation des plantes entomophiles, notre étude souligne la nécessité de créer une diversité d'habitats interconnectés, gérés de façon optimale, qui se complètent mutuellement dans les ressources qu'ils offrent. Pour atteindre cet objectif, la PAC post‐2020 doit adopter une vision holistique de la mise en œuvre des différents leviers de protection de la biodiversité (e.g. éco‐conditionnalité renforcée, programmes verts ou ‘eco‐schemes’, mesures agro‐environnementales et climatiques). Pour réellement améliorer la qualité des habitats, nous recommandons des suivis efficaces de la biodiversité à l'aide d'indicateurs pertinents. Enfin, pour optimiser la disposition spatiale des SIE et leur connectivité, la collaboration entre les différents gestionnaires des espaces agricoles doit être encouragée.
Samenvatting
De achteruitgang van bestuivende insecten in het landelijk gebied is voornamelijk het gevolg van intensivering van de landbouw en het daarmee gepaard gaande verlies van geschikt voedsel‐ en nestelhabitat. Om de impact van de landbouw op het milieu te verminderen zijn in 2014 binnen het EU Gemeenschappelijk landbouwbeleid (GLB) een aantal Ecologische Aandachtsgebieden (Ecological Focus Areas, EFAs) vastgesteld die boeren kunnen implementeren om te voldoen aan de eisen voor directe inkomenssteun. In deze studie hebben we, ten behoeve van de hervorming van het GLB voor de periode na 2020, op Europese schaal een evaluatie uitgevoerd van de potentiële waarde van verschillende EFAs voor bestuivers. De waarde van EFAs is hierbij beoordeeld onder gangbaar beheer en in het geval het beheer voor bestuivers geoptimaliseerd zou worden.
De evaluatie is uitgevoerd door middel van de Delphi‐methode, waarbij 22 experts uit 18 Europese landen betrokken waren. Op basis van de levenscyc
The organised storage of spectral data described by metadata is important for long-term use and data sharing with other scientists. Metadata describing the sampling environment, geometry and ...measurement process serves to evaluate the suitability of existing data sets for new applications. There is a need for spectral databases that serve as repositories for spectral field campaign and reference signatures, including appropriate metadata parameters. Such systems must be (a) highly automated in order to encourage users entering their spectral data collections and (b) provide flexible data retrieval mechanisms based on subspace projections in metadata spaces.
The recently redesigned SPECCHIO system stores spectral and metadata in a relational database based on a non-redundant data model and offers efficient data import, automated metadata generation, editing and retrieval via a Java application.
RSL is disseminating the database and software to the remote sensing community in order to foster the use and further development of spectral databases.
SLSTR is a high accuracy infrared radiometer which will be embarked in the Earth low-orbit Sentinel 3 operational GMES mission. SLSTR is an improved version of the previous AATSR and ATSR-1/2 ...instruments which have flown respectively on Envisat and ERS-1/2 ESA missions. SLSTR will provide data continuity with respect to these previous missions but with a substantial improvement due to its higher swaths (750 km in dual view and 1400 km in single view) which should permit global coverage of SST and LST measurements (at 1 km of spatial resolution in IR channels) with daily revisit time, useful for climatological and meteorological applications. Two more SWIR channels and a higher spatial resolution in the VIS/SWIR channels (0.5 km) are also implemented for a better clouds/aerosols screening. Two further additional channels for global scale fire monitoring are present at the same time as the other nominal channels.
The product generation from hyperspectral sensor data has high requirements on the processing infrastructure, both hardware and software. The Airborne Prism Experiment (APEX) processing and archiving ...facility has been set up to provide for the automated generation of level-1 calibrated data and user-configurable on-demand product generation for higher processing levels. The system offers full reproducibility of user orders and processing parameters by employing a relational database. The flexible workflow software allows for the quick integration of novel algorithms or the definition of new processing sequences. Reprocessing of data is supported by the archiving approach. Configuration management based on the database enables the control over different versions of processing modules to be applied. The system is described with a focus on the APEX instrument; however, its generic design allows adaptation to other sensor systems.
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