. Istanbul 2004
been analysed,
)e 4
ter to be daily
(f 1000 x 1000
been acquired
ed.
the authorized
the extensive
20° access
1 stereoscopic
stereoscopic
different B/H,
iplet with the
in the pitch
ion becomes
! acquisition is
ontours (using
object images
…. These image
he very low
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B1. Istanbul 2004
able B/H as they are also used to improve correlation
RS and to limit disparity between stereo images.
B/H Stereo length Tri -stereo length
0.15 20 km -
0.2 60 km -
0.3 120 km 20 km
0.4 175 km 60 km
0.5 225 km 90 km
0.6 280 km 120 km
0.7 300 km 145 km
0.8 300 km 175 km
0.9 300 km 205 km
1 300 km 255 km
Table 14 : Maximum length of stereo coverage
4.8.4 Instantaneous mosaic coverage capabilities
High agility allows also swath enlargement by contiguous
strips, even in East/West direction of acquisition. Mosaic
images ranging from 60 x 200 km2 (3 strips) to 120 x 65 km2
(6 strips) with 20? access authorized, and from 60 x 340 km2
(3 strips) to 140 x 105 km2 (6 strips) with 30? access
authorized, can be acquired.
4.8.5 Mean Acquisition capabilities over a year
Due to high agility coupled with high image storage and
downlink capacities, Pléiades satellite coverage capability
reaches around 30 000 km? per orbit (summer season) and an
average area of more than 2 500 000 km? over a year. This
annual capacity includes weather statistics, that is
corresponds to cloud free images.
5 CONCLUSION
Pleiades is not the SPOT-5 follow-on program but more a
new concept for Earth Observation, which is proposed,
through a wider European cooperation, to satisfy the needs of
all scientific, institutional (including Defense) and private
users for satellite imagery.
The Optical High Resolution component of Pléiades, Pléiades
HR, has been decided and is in its realization phase. With its
two satellites it represents the French part of the ORFEO
program which is completed by four SAR-X satellites
provided by Italy within its COSMO-SkyMed program. The
two systems will provide high-resolution (metric) imagery
with a very short revisit time (24 h for optical, 12 h for SAR)
to satisfy dual requirements, as defined in an
intergovernmental agreement between the two Countries.
Beyond this current industrial realization there is still a need
to develop new tools and/or new processes to optimize the
use of these future data. This implies close links with the
different user communities, value-added companies and all
actors involved in Earth Observation.
In order to prepare users in France and Italy, then in Europe,
to ORFEO utilization an ORFEO preparatory program has
been settled in 2003. It should last from 2004 to 2008. Two
complementary aspects are identified: methodology (tool
development) and thematic applications (tool usage to get
useful information from image data). Tools and processes are
developed by scientists in close cooperation with image
processing specialists for end users who should assess these
tools and implement them within their routine processes.
Seven work axes have been defined, while differentiating 2D
methods from 3D methods.
For 2D methods:
— Multi-scale, multi-resolution issues and coupling with
exogenous data
— Very High Resolution SAR data
— Object models and statistical / dynamical image analysis
— Scene models and global/structural image analysis
For 3D methods:
— Urban studies from optical images
— Deformation characterization
— 3D models from SAR data
There is also a need to develop, with European and maybe
not-European partners new systems providing SPOT-5 like
data, whose demand is increasing either from the current
SPOT users or from new ones.
The Global Monitoring for Environment and Security
(GMES), at the European level, as the Group on Earth
Observations (GEO) at the international level are
encouraging initiatives which should help for a decision to
implement the necessary space and ground infrastructures
within the proposed Global Earth Observation System of
Systems (GEOSS) which should be defined by the end of this
year and decided next year for a 10 year period.
REFERENCES
Baudoin A., 1999, The current and future SPOT program.
ISPRS Workshop Hanover 1999
Baudoin A., 2001, « Pléiades: a Multi Mission and Multi
Cooperative Program”, 52 "d International Astronautical
Congress/Toulouse, France, October 2001
Caltagirone F., 2000, COSMO-SkyMed Mission Overview
Proceeding of NATO/SET Symposium on Space-Based
Observation Techniques Samos — Greece 2000
Damilano P., 2001, “Pleiades High Resolution Satellite: a
Solution for Military and Civilian Needs in Metric-Class
Optical Observation", 15th Annual/USU Conference on
Small Satellites, August 2001
Koneeny G., 1999, Mapping from Space - ISPRS Workshop
Hanover 1999
Kubik P., 2002, *Pleiades-HR image quality design", ACSM
- ASPRS 2002 Annual conference proceedings
Massonnet D., 1999, Capabilities and Limitations of the
Interferometric CartWheel, CEOS SAR Workshop, Oct. 1999,
Toulouse, paper 136
ACKNOWLEDGMENTS
Special thanks have to be given to Eric Boussarie, Alain
Gleyzes and Jean-Michel Lachiver from CNES Pléiades
team, who have provided all technical information of
Chapter 4.
