IEEE Geoscience and Remote Sensing Magazine - June 2015 - 41

space agencies
P. Ultré-Guérard and B. Boissin
Centre National d'Etudes Spatiales, Paris, France

The CNES Earth Observation Program
Abstract-This paper provides an overview of the
Earth Observation activities of the French Space Agency.
I. INTRODUCTION
he fact that satellites can scan the Earth in just a few
hours or observe certain points on the globe on a
permanent basis makes them an extraordinary tool
for monitoring the planet's health. Combining satellite
observations with in situ measurements and physical
models enables to study the interactions between the
Earth's component envelopes, from its core to the highest layers of the atmosphere and to learn more about its
ongoing evolution. Such observations are essential to
improve forecasts of some geophysical phenomena, as
with meteorology or oceanography.
The issues of human impact on the environment and
climate change, as well as the management and mitigation of major disasters, etc. are just some of the challenges faced by current and future generations. Satellites
play an essential role in this quest for knowledge and
sustainable management of the environment.
CNES (Centre National d'Etudes Spatiales) participates to these efforts either through national missions
often in multilateral cooperation with other space
agencies or operational agencies, such as Eumetsat, or
through France's participation in ESA's Earth Observation Programs (European Space Agency) (Earth Explorer,
Earth Watch or ESA-EU Copernicus programs).
Over the past thirty years CNES has developed significant expertise in imaging, altimetry and sounding
and has worked to share this expertise in the development of operational missions in the frame work of
the Copernicus and Eumetsat programs. CNES has the
objective to maintain this expertise and is working in
close concertation with the French scientific community to give access to new, innovative measurements.
At last but not least, CNES aims to facilitate the access
to missions' data and foster the development of services
and applications.

Digital Object Identifier 10.1109/MGRS.2015.2443152
Date of publication: 30 July 2015

june 2015

ieee Geoscience and remote sensing magazine

II. ON GOING AND PLANNED MISSIONS
CNES contributes to eleven satellites in operation
(Figure 1: CNES supported Earth Observation missions in operation) and seven currently under development for a launch in the next six years (Figure 2:
CNES supported Earth Observation missions in
development). [1]
All these satellites are either demonstrators of new
concepts or first elements of operational series of satellites and pave the way for operational services such as
those developed within the European Copernicus program (Sentinels-1 to -6), the Eumetsat program (Meteosat, Metop, Jason) or purely commercial programs
(SPOT 6 and SPOT 7).
A. LAND OBSERVATORIES
1) HigH resolution imagery: sPot family
Launched in 2002, SPOT 5 continued the SPOT series of
satellites with a new high resolution instrument HRG,
offering a 2,5m spatial resolution and a 60 km swath. A
stereoscopic instrument HRS was also flown allowing
the satellite to efficiently map terrain in three dimensions (Figure 3) with one decametre height accuracy and
a 120km swath.
Despite the fact that SPOT 5 remains in good condition, it will be de-orbited by the end of 2015 in order
to respect the French law on space debris. For its last 5
months, from April 2015 to September 2015, it will be
placed in a 5 day repeat orbit cycle to observe hundred
of ground sites and as such to prepare the Sentinel-2
mission (Take 5: [2]).
Continuity in this type of imagery will be
ensured by the high resolution capability of Spot
6-7 satellites which have been fully funded by the
private sector, Airbus Defence and Space (Airbus
DS). For its decametric multispectral capability the
Copernicus Sentinel-2 will generate global coverage with a 5 days revisit. CNES is strongly involved
in Sentinel-2 through its expertise and technical
support to ESA on image quality monitoring and in
orbit commissioning.
0274-6638/15©2015IEEE

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