VENUS (Vegetation and Environment New µ-Spacecraft) A demonstration space mission dedicated to land...
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VENUSVENUS((Vegetation and Environment New µ-Spacecraft) Vegetation and Environment New µ-Spacecraft)
AA demonstration space mission dedicated to land demonstration space mission dedicated to land surface environment surface environment in the framework of GMES
Selma CHERCHALI, Directorate for Strategy and Programmes, Earth ObservationLand Environment Programme Manager
Context and objectives of the mission
■Despite the existing panoply of space sensors, appropriate measurements tools are still lacking
Very high spatial and temporal variability of earth surfaces parameters, e.g. fast vegetation growth in small crop fields
Earth observation missions currently covering either the temporal variability (AVHRR, VEGETATION, MERIS, MODIS, MSG…) or the spatial variability (SPOT, Landsat…)
Increasing scientific and social demand in environment issues related to land surface environment, e.g. sustainable development, management of water resources and natural or cultivated ecosystems...
Recent and significant scientific advances in the modelling of land surface processes at all scales
■Conciliating the capability to characterise the high spatial variability of land surfaces with its rapid evolution in time is the main driving force of the mission concept
■ Monitoring and understanding the vegetation cycles to improve functioning models
Access to the dynamic of surfaces
■ Useful information over land retrieved from remote sensing data
Reflectances, vegetation index, leaf area index, albedo, surface temperature, solar irradiance, precipitation
Land cover maps Net primary productivity (from simplified model forced by remote sensing data) Time evolution of these variables ...
Need to provide simultaneously high spatial resolution and high temporal revisit data to solve land cover heterogeneity and vegetation dynamics
Context and objectives of the mission
VENµS
■ObjectivesTo provide data for research on land surface functioning : land cover & land
use, water and carbon exchanges, snow
To provide data for research on land surface functioning : land cover & land use, water and carbon exchanges, snow
Data assimilation Automatic land cover mapping Validation of medium resolution satellite products Demonstration of the use of RS data for the implementation of Environmental
regulations (e.g. Grenelle laws in France)
■Main specificity of Venµs multi-temporal observations with constant observation angles
Before the operational space infrastructure, VENUS is a demonstration mission aiming at studying the technical feasibility of the concept and at developing scientific methods over a sample of ground research sites
Developing new processing algorithms is one of Venµs missions VENUS is a demonstration mission which aims is to demonstrate the benefit of
superspectral, high resolution, high revisit frequency, and high quality measurements. One objective of VENUS is
– i) to be the precursor of an operational mission (Sentinel 2) with such characteristics and full global coverage and
– ii) to develop pre-processing algorithms, methods, and applications that will use these data.
(From Venµs Mission Requirements)
VENUS : a demonstration mission in the framework of GMES
Image Features
Venµs image characteristics Resolution 5m-10m, Field of View 27 km 12 spectral bands from 412 to 910 nm Systematic acquisition of 50 sites every second day 2 stereoscopic bands with a low angle difference Constant viewing angle ==> Directional effects are minimised
VENS organization
Israeli Space Agency designs, manufactures and tests the VENS Platform (IMPS). Manufactured by IAI-MBT
CNES is responsible for the camera (manufactured by Elop)
Scientific mission (720 km) 2.5 years
Technological mission (410 km) – 1 year
Orbit change
End of the commissioning phase electrical propulsion system Launch
2012
3 months
~250 kg
■ CNES develops and operates the Science Mission Center and Image Ground Segment (SMIGS), and makes the data available to the users
Programmatic aspects : GMES
■GMES services dedicated to earth environment are under development and validation by the European Commission and ESA, with the support of national space agencies. Services are expected to be operational by 2013;
Services dedicated to land environment are amongst the top priority themes of GMES
■The GMES Space component (sentinels + national missions) specifications have to fulfil the user requirements (priorities, sensors, revisit time, continuity of data…) especially for the first fast tracks “oceanography”, “land monitoring”, “emergency” (and the next ones : atmosphere, security).
The SPOT satellites will be beyond their expected lifetime by 2012 The Sentinel 2 will be the future operational infrastructure for feeding the GMES
services (2013)
a way up to operational services by 2013
■ Venµs is a scientific mission : limited number of sites, no continuity. Free access to the data.
■The European Sentinel-2 mission will provide global coverage of high resolution superspectral data, every 10 days with one satellite and every 5 days with two satellites
One clear image every 15 to 30 days
■ESA, coordinator of the GSC, takes into account the national missions and plans in order to make the GSC coherent, complete and affordable for the users/CE.
■Contribution through national / multi-lateral programme : Demonstration mission : Vénμs
Programmatic aspects : GMES
And what’s the next?
Moreover, a major challenge is to be ready to provide on a operational basis the data and the models required to support the strong evolution of agricultural, environmental and security policies and to feed decision support system (GMES)
■After the race for resolution, the next step will be ~daily revisit with decametric resolution, everywhere (systematic coverage).