HR: 1340h
AN: A33C-0915    [Abstracts]
TI: In-Flight Performance of PARASOL Inside the Aqua-Train Atmospheric Observatory
AU: * Fougnie, B
EM: Bertrand.Fougnie@cnes.fr
AF: Centre National d'Etudes Spatiales, 18 av. E.Belin Cedex 9, Toulouse, 31401 France
AU: Bracco, G
EM: Guillaume.Bracco@magellium.fr
AF: Magellium, 10 av. de l'Europe, Ramonville St-Agne, 31520 France
AU: Lafrance, B
EM: Bruno.Lafrance@c-s.fr
AF: CS-SystŠmes d'Information, rue Brindejonc des moulinais Cedex 5, Toulouse, 31506 France
AU: Ruffel, C
EM: Caroline.Ruffel@c-s.fr
AF: CS-SystŠmes d'Information, rue Brindejonc des moulinais Cedex 5, Toulouse, 31506 France
AU: Hagolle, O
EM: Olivier.Hagolle@cnes.fr
AF: Centre National d'Etudes Spatiales, 18 av. E.Belin Cedex 9, Toulouse, 31401 France
AB: PARASOL, Polarization and Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar, launched the 18th December 2004, is a microsatellite developed by the Franch Space Agency (CNES) carrying a wide-field of view imaging radiometer called POLDER and designed in partnership with the Atmospheric Optics Laboratory (LOA). The PARASOL instrument analyses a threefold signature : polarization, for different viewing angles and for 9 spectral bands from visible to near-infrared. In addition, PARASOL scientific goals are to improve the characterization of microphysical properties of clouds and aerosols using the complementary data provided by sensors composing the Afternoon-train observatory (MODIS, CALIPSO, CLOUDSAT). During the image quality commissioning phase, ended in June 2005, activities were conducted to complete in-flight geometric and radiometric calibration and evaluate the system performance regarding to mission specifications and scientific goals. Massive correlations between various images were used to assessed the in-flight geometric calibration and registration performances between polarized, spectral, and multi-directional observations which were found to be compatible with specifications, i.e. better than 0.05, 0.10, and 0.10 pixel respectively. The absolute location accuracy was estimated at 2-3km (note that pixel of the level-1 data grid are 6.18km). The in-flight radiometric calibration activity includes various aspects : absolute, multi-temporal, multi-angular and in-polarization calibrations, dark current and non-linearity characterization, optimization of the dynamic range. Because of the absence of on-board calibration device, these characterizations were assessed through methods based on acquisitions over well-defined natural targets : i/ Rayleigh scattering over predefined oceanic sites, ii/ spectrally flat sunglint over ocean, iii/ bright, high and spectrally flat convective clouds, iv/ pre-defined and well-characterized desert sites. The resulting absolute calibration accuracy is estimated at better than 3% while the interband calibration accuracy is nearly 1% from 490 to 1020nm At the exception of 2 open issues (a stray-light contamination leading to degraded performances at 443-nm, and a geometric performance slightly degraded 3 days per month during transits of the moon into the field-of-view of the star-tracker), performances are found to be very satisfactory, the quality of PARASOL level-1 data is now guaranteed for a full scientific exploitation.
UR: http://parasol-polder.cnes.fr/
DE: 0545 Modeling (4255)
DE: 0694 Instruments and techniques
DE: 1610 Atmosphere (0315, 0325)
DE: 3360 Remote sensing
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005