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GMES is a joint initiative of the European
Commission (EC) and the European Space Agency
(ESA), designed to establish a European capacity for
the provision and use of operational monitoring
information for environment and security applications.
ESA’s role in GMES is to provide the definition and
the development of the space- and ground-related
system elements. GMES Sentinel-2 mission provides
continuity to services relying on multi-spectral highresolution
optical observations over global terrestrial
surfaces. The key mission objectives for Sentinel-2
are: (1) to provide systematic global acquisitions of
high-resolution multi-spectral imagery with a high
revisit frequency, (2) to provide enhanced continuity
of multi-spectral imagery provided by the SPOT series
of satellites, and (3) to provide observations for the
next generation of operational products such as landcover
maps, land change detection maps, and
geophysical variables. Consequently, Sentinel-2 will
directly contribute to the Land Monitoring,
Emergency Response, and Security services. The
corresponding user requirements have driven the
design towards a dependable multi-spectral Earthobservation
system featuring the MSI with 13 spectral
bands spanning from the visible and the near infrared
to the short wave infrared. The spatial resolution
varies from 10 m to 60 m depending on the spectral
band with a 290 km field of view. This unique
combination of high spatial resolution, wide field of
view and large spectral coverage will represent a
major step forward compared to current multi-spectral
missions. The mission foresees a series of satellites,
each having a 7.25-year lifetime (extendable to 12
years) over a 20-year period starting with the launch
of Sentinel-2A foreseen by mid-2014. During full
operations two identical satellites will be maintained
in the same sun synchronous orbit with a phase delay
of 180° providing a revisit time of five days at the
equator.
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