In: Wagner W., Szekely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B 
data, final image product) and data access services (online 
catalogued data browsing, product ordering) definitions have 
been major issues (Baillarin 2006). 
The UGCs, including the image processing algorithms, have 
successfully passed system tests and are now fully integrated 
and ready for operations. 
Figure 2: Pleiades-HR Ground Segment 
geometric distortions (viewing directions and high frequency 
attitude variations), but no ground projection is operated. All 
multispectral (XS) and panchromatic (PA) pixels are 
registered. 
XS can be PAN-sharpened in the same processing flow to 
obtain a 0.50 m GSD 4-band colour image (blue, green, red, 
near infrared). 
This product can be accurately located by rational functions: in 
addition to Pleiades-HR physical model, metadata contains 
direct and inverse location models that can be used by 
commercial software. 
2.4 Ortho-image and Mosaic Level 
The Pleiades-HR ortho-image is resampled into a cartographic 
projection and corrected from sensor and terrain distortions. 
This product must be very precisely located to be used into 
geographic information systems (GIS). Product location is 
checked on an accurate DEM (Reference3D™, if available) 
with automatic GCPs (algorithm based on (Baillarin 2004)]). 
Users can also give their own DEM for ortho-rectification. The 
final product contains associated quality metadata. 
Pleiades-HR ortho-images can also be PAN-sharpened to 
obtain a 0.50 m GSD 4-band colour image. 
Mosaics products are larger size ortho-images, automatically 
processed as a seamless patchwork of individual strips. This is 
made possible thanks to the high agility and the precise 
pointing capability of the platform. The strips are all converted 
is same geometry, using automatically computed tie points and 
ground control points, then radiometrically homogenised, then 
joined together using computed stitching-line. 
3. SIMPLIFYING THE FOCAL PLANE: THE 
“SENSOR” PRODUCT 
A light version of the UGC, with image reception and 
production capabilities, is also available for any foreign users 
willing to receive and produce Pleiades-HR images (e.g. 
Kiruna Station). 
2.2 Image products 
Several types of products have been defined in order to fulfil 
the user needs considering that the remote sensing community 
is generally divided in two groups: 
Users needing data for mapping purposes or using Geographic 
Information Systems (GIS), whatever the sensors 
characteristics. They usually use ortho-image products, which 
are resampled into cartographic projections and corrected from 
sensor and terrain distortions. 
Users wanting to process “raw data” in order to deliver value- 
added products (such as 3D, geophysics data, ...) using their 
own methods. They need comprehensive ancillary data to 
compute the geometric model. Because of the specific 
geometry of Pleiades-HR focal plane (Kubik 2005), a “Sensor 
Level” product has been defined making the geometric model 
simpler while preserving its accuracy. 
Hence, two processing levels have been defined in addition to 
the classical raw levels. They are presented and assessed here 
after. 
2.3 Sensor Level 
The Sensor Level product corresponds to the image that would 
have been delivered by a perfect standard push-broom sensor. 
The product is only corrected from on-board radiometric and 
The complexity of the Pleiades-HR focal plane makes the 
classical level 1 product difficult to use. A new product level 
called “Sensor Level” is proposed (De Lussy 2006). 
This Sensor Level product consists in a basic product specially 
designed for the photogrammetric community and delivered 
with a physical model and a rational function model. 
The purpose is to generate the image which would have been 
acquired by a simpler push-broom sensor (SPOT-like) in the 
same imaging conditions in order to be able to exploit the 
geometric characteristics of the image (such as DEM or 3D 
extraction) without having to take into account the complex 
geometry of the real sensor. 
3.1 Perfect Sensor Geometry 
Due to the complexity of the focal plane (mainly because of the 
detector layout composed of five slightly tilted TDI arrays for 
the PA and five CCD arrays for each XS band), the raw 
products should be considered as 25 different products with 
their own geometrical models. 
a 20 mm 
Multispectral detector arrays 
Panchromatic TDI component 
Virtual Perfect Sensor array 
♦ * j mm 
i » 1 mm 
a 400 mm