Notice: Function acf_get_value was called incorrectly. Advanced Custom Fields PRO - We've detected one or more calls to retrieve ACF field values before ACF has been initialized. This is not supported and can result in malformed or missing data. Learn how to fix this. Please see Debugging in WordPress for more information. (This message was added in version 5.11.1.) in /home/www-data/wpicare/wp-includes/functions.php on line 6121

Notice: Function acf_get_value was called incorrectly. Advanced Custom Fields PRO - We've detected one or more calls to retrieve ACF field values before ACF has been initialized. This is not supported and can result in malformed or missing data. Learn how to fix this. Please see Debugging in WordPress for more information. (This message was added in version 5.11.1.) in /home/www-data/wpicare/wp-includes/functions.php on line 6121

Notice: Function acf_get_value was called incorrectly. Advanced Custom Fields PRO - We've detected one or more calls to retrieve ACF field values before ACF has been initialized. This is not supported and can result in malformed or missing data. Learn how to fix this. Please see Debugging in WordPress for more information. (This message was added in version 5.11.1.) in /home/www-data/wpicare/wp-includes/functions.php on line 6121

Notice: Function acf_get_value was called incorrectly. Advanced Custom Fields PRO - We've detected one or more calls to retrieve ACF field values before ACF has been initialized. This is not supported and can result in malformed or missing data. Learn how to fix this. Please see Debugging in WordPress for more information. (This message was added in version 5.11.1.) in /home/www-data/wpicare/wp-includes/functions.php on line 6121

Notice: Function acf_get_value was called incorrectly. Advanced Custom Fields PRO - We've detected one or more calls to retrieve ACF field values before ACF has been initialized. This is not supported and can result in malformed or missing data. Learn how to fix this. Please see Debugging in WordPress for more information. (This message was added in version 5.11.1.) in /home/www-data/wpicare/wp-includes/functions.php on line 6121

Notice: Function acf_get_value was called incorrectly. Advanced Custom Fields PRO - We've detected one or more calls to retrieve ACF field values before ACF has been initialized. This is not supported and can result in malformed or missing data. Learn how to fix this. Please see Debugging in WordPress for more information. (This message was added in version 5.11.1.) in /home/www-data/wpicare/wp-includes/functions.php on line 6121

Notice: Function _load_textdomain_just_in_time was called incorrectly. Translation loading for the cookie-law-info domain was triggered too early. This is usually an indicator for some code in the plugin or theme running too early. Translations should be loaded at the init action or later. Please see Debugging in WordPress for more information. (This message was added in version 6.7.0.) in /home/www-data/wpicare/wp-includes/functions.php on line 6121

Notice: Function _load_textdomain_just_in_time was called incorrectly. Translation loading for the better-wp-security domain was triggered too early. This is usually an indicator for some code in the plugin or theme running too early. Translations should be loaded at the init action or later. Please see Debugging in WordPress for more information. (This message was added in version 6.7.0.) in /home/www-data/wpicare/wp-includes/functions.php on line 6121

Notice: Function _load_textdomain_just_in_time was called incorrectly. Translation loading for the multilingual-press domain was triggered too early. This is usually an indicator for some code in the plugin or theme running too early. Translations should be loaded at the init action or later. Please see Debugging in WordPress for more information. (This message was added in version 6.7.0.) in /home/www-data/wpicare/wp-includes/functions.php on line 6121

Warning: session_start(): Session cannot be started after headers have already been sent in /home/www-data/wpicare/wp-content-icare/plugins/multilingual-press/inc/redirect/Mlp_Redirect_Frontend.php on line 93

Warning: Cannot modify header information - headers already sent by (output started at /home/www-data/wpicare/wp-includes/functions.php:6121) in /home/www-data/wpicare/wp-content-icare/plugins/web-connection-security/controllers/Base.php on line 69

Warning: Cannot modify header information - headers already sent by (output started at /home/www-data/wpicare/wp-includes/functions.php:6121) in /home/www-data/wpicare/wp-content-icare/plugins/web-connection-security/controllers/Base.php on line 70

Warning: Cannot modify header information - headers already sent by (output started at /home/www-data/wpicare/wp-includes/functions.php:6121) in /home/www-data/wpicare/wp-content-icare/plugins/web-connection-security/controllers/Base.php on line 45

Warning: Cannot modify header information - headers already sent by (output started at /home/www-data/wpicare/wp-includes/functions.php:6121) in /home/www-data/wpicare/wp-content-icare/plugins/web-connection-security/controllers/Base.php on line 49

Warning: Cannot modify header information - headers already sent by (output started at /home/www-data/wpicare/wp-includes/functions.php:6121) in /home/www-data/wpicare/wp-content-icare/plugins/web-connection-security/web-connection-security.php on line 27

Warning: Cannot modify header information - headers already sent by (output started at /home/www-data/wpicare/wp-includes/functions.php:6121) in /home/www-data/wpicare/wp-content-icare/plugins/multilingual-press/inc/hreflang-header/Mlp_Hreflang_Header_Output.php on line 145

Warning: Cannot modify header information - headers already sent by (output started at /home/www-data/wpicare/wp-includes/functions.php:6121) in /home/www-data/wpicare/wp-content-icare/plugins/multilingual-press/inc/hreflang-header/Mlp_Hreflang_Header_Output.php on line 145
PROGRA2 – PRopriétés Optiques des GRains Astronomiques et Atmosphériques

PROGRA2

PRopriétés Optiques des GRains Astronomiques et Atmosphériques

Les instruments PROGRA2 (PRopriétés Optiques des GRains Astronomiques et Atmosphérique) effectuent depuis 1994 des mesures sur la diffusion lumineuse par des nuages de particules solides irrégulières en suspension ou déposées en surface. Les mesures en lévitation sont effectuées en impesanteur lors de vols paraboliques à bord de l’A300 ZeroG puis de l’A310 ZeroG dans le cadre de campagnes financées par le CNES et l’ESA, mais aussi en laboratoire pour les particules les plus petites en utilisant une technique de soulèvement par injection d’air. Les mesures sont conduites pour différentes longueurs d’onde entre 450 et 1600 nm.

            Des centaines de courbes de diffusion lumineuses ont ainsi été obtenues dans ces différentes conditions pour des échantillons caractéristiques des matériaux trouvés sur Terre, dans l’atmosphère et dans l’espace (cendres volcaniques, basaltes, sables, carbones, météorites, carbure de silicium, …). Certains échantillons sont fabriqués en laboratoire, comme des analogues cométaires et interplanétaires, et des tholins. Toutes ces courbes sont utilisées pour interpréter les mesures effectuées à distance depuis des télescopes, des sondes spatiales et des instruments sous ballons atmosphériques, de la lumière solaire diffusée par les particules. Il est ainsi possible de mieux caractériser certaines propriétés physiques de ces particules solides, telles que leur taille, leur nature et leur porosité.  Le projet a été principalement financé par le CNES.



Rechercher