IEEE Geoscience and Remote Sensing Magazine - June 2015 - 43

satellites, have monitored the Earth's biosphere. They
offered quasi daily coverage of the Earth with a kilometric resolution in four spectral bands (blue, red, near infrared and short wave infrared).
The 16 years Vegetation data base is invaluable to better
understand plant cover's role in carbon and water cycles on
a global scale and interactions between Earth's biosphere
and global changes.
Proba V, fully funded by Belgium and operated by ESA,
ensures service continuity since 2013 with a better resolution than Vegetation.
b) Venns (Vegetation and enVironment
monitoring on a new microsatellite)
The Venns mission [4] is a joint French-Israeli venture
whose aim is monitoring changes in plant cover every two
days over predefined sites of interest, using a high-resolution superspectral camera (11 spectral bands). Currently
scheduled for a 2016 launch, data from Venns will pave the
way for new land-use and vegetation monitoring services
with a very high repetitivity.
4) Biomass
Biomass is the 8th ESA Earth Explorer mission. Its objectives are to acquire, P-band repeat-pass data over forest to
map biomass on a global scale using SAR (Synthetic Aperture Radar) techniques such as polarimetry, interferometry and tomography, thus helping to achieve sustainable
management of forests and gain new insights into how our
planet's climate works.
CNES has contributed significantly to the mission
definition especially through data exploitation of the two
campaigns TROPISAR (airborne campaign) and TROPISCAT (ground based campaign to evaluate signal coherence) on tropical forest in French Guiana. The advanced
techniques developed by the teams (polarimetry, interferometry and tomography) have helped to consolidate
and improve the mission.
5) Hydrology: sWoT (surface WaTer
and ocean TopograpHy)
SWOT [5] mission objective is to measure water heights
(and their space-time variations) of rivers, lakes and
flooded zones as well as oceans. For continental surfaces, this mission will measure at large scale changes in
water storage of the main lakes and reservoirs, as well as
enable to evaluate with a higher accuracy the flow rates
of major rivers.
The interferometric altimeter KaRIN (Ka-band Radar
INterferometer) will give a bi-dimentional image with a
horizontal resolution of about 50-100 m. It includes two
Ka-band SAR antenna, mounted at each end of a 10 m
boom structure, respectively providing a lage ground track
of 120 km large (Figure 5). With its large swath, the SWOT
satellite will cover all the lakes, rivers, reservoirs and oceans
of the Earth, at least twice every 21 days.
june 2015

ieee Geoscience and remote sensing magazine

Figure 3. The SPOT 5 satellite maps terrain in three dimensions
Andes mountains-August 2003.

Figure 4. Pleiades agility 3 faces of the Mecca "tower clock" Saudi

Arabia acquired during one pass ©CNES 2012 Distribution Airbus DS.
SWOT is developed in cooperation with NASA
(National Aeronautics and Space Administration) and is
to be launched in 2020.
B. OCEAN OBSERVATORIES
1) salT and THe climaTe: smos
(soil moisTure and ocean saliniTy)
SMOS [6] measures both soil moisture and ocean salinity
(Figure 6). Both are key variables in climate monitoring,
surface/vegetation/atmosphere transfers, and ocean/atmosphere cycles, which are used in predictive atmospheric,
oceanographic, and hydrologic models. Space observation
is the only means to date to measure directly and globally
these key variables.
The mission, launched in 2009, was jointly developed by
ESA, CNES and CDTI (Centro para el Desarrollo Technologico Industrial), Spain's space agency. The instrument, an
L-Band interferometric radiometer with a spatial resolution
of 50 km, measures surface soil moisture and the ocean surface salinity every 3 days on a global scale.
2) alTimeTry: Jason, alTika, sWoT
Following the retirement of the Topex-Poseidon (1992-2006)
and Jason 1 (2001-2013) satellite, the service continuity is
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Table of Contents for the Digital Edition of IEEE Geoscience and Remote Sensing Magazine - June 2015