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Proceedings Paper • Open Access

First in-flight results of Pleiades 1A innovative methods for optical calibration
Author(s): Philippe Kubik; Laurent Lebègue; Sébastien Fourest; Jean-Marc Delvit; Françoise de Lussy; Daniel Greslou; Gwendoline Blanchet

Paper Abstract

The PLEIADES program is a space Earth Observation system led by France, under the leadership of the French Space Agency (CNES). Since it was successfully launched on December 17th, 2011, Pleiades 1A high resolution optical satellite has been thoroughly tested and validated during the commissioning phase led by CNES. The whole system has been designed to deliver submetric optical images to users whose needs were taken into account very early in the design process. This satellite opens a new era in Europe since its off-nadir viewing capability delivers a worldwide 2- days access, and its great agility will make possible to image numerous targets, strips and stereo coverage from the same orbit. Its imaging capability of more than 450 images of 20 km x 20 km per day can fulfill a broad spectrum of applications for both civilian and defence users.

For an earth observing satellite with no on-board calibration source, the commissioning phase is a critical quest of wellcharacterized earth landscapes and ground patterns that have to be imaged by the camera in order to compute or fit the parameters of the viewing models. It may take a long time to get the required scenes with no cloud, whilst atmosphere corrections need simultaneous measurements that are not always possible.

The paper focuses on new in-flight calibration methods that were prepared before the launch in the framework of the PLEIADES program : they take advantage of the satellite agility that can deeply relax the operational constraints and may improve calibration accuracy. Many performances of the camera were assessed thanks to a dedicated innovative method that was successfully validated during the commissioning period : Modulation Transfer Function (MTF), refocusing, absolute calibration, line of sight stability were estimated on stars and on the Moon. Detectors normalization and radiometric noise were computed on specific pictures on Earth with a dedicated guidance profile. Geometric viewing frame was determined with a particular image acquisition combining different views of the same target.

All these new methods are expected to play a key role in the future when active optics will need sophisticated in-flight calibration strategy.

Paper Details

Date Published: 20 November 2017
PDF: 10 pages
Proc. SPIE 10564, International Conference on Space Optics — ICSO 2012, 1056407 (20 November 2017); doi: 10.1117/12.2309056
Show Author Affiliations
Philippe Kubik, Ctr. National d'Études Spatiales (France)
Laurent Lebègue, Ctr. National d'Études Spatiales (France)
Sébastien Fourest, Ctr. National d'Études Spatiales (France)
Jean-Marc Delvit, Ctr. National d'Études Spatiales (France)
Françoise de Lussy, Ctr. National d'Études Spatiales (France)
Daniel Greslou, Ctr. National d'Études Spatiales (France)
Gwendoline Blanchet, Ctr. National d'Études Spatiales (France)

Published in SPIE Proceedings Vol. 10564:
International Conference on Space Optics — ICSO 2012
Bruno Cugny; Errico Armandillo; Nikos Karafolas, Editor(s)

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