PARASOL descend du Train / PARASOL gets off the Train

Après presque 5 ans de mesures simultanées avec les satellites de l'A-Train, le microsatellite PARASOL a quitté sa position au sein de la constellation à 12:48 TU, le 2 décembre 2009. La manoeuvre d'abaissement d'orbite réalisée par les équipes opérationnelles du CNES a permis d'atteindre une orbite à 3.9 km sous l'A-Train. PARASOL avait rejoint la constellation A-Train début février 2005. Depuis plusieurs mois déjà, la trace au sol de PARASOL dérivait lentement vers l'Est par rapport à celle des autres satellites de l'A-train car les réserves en carburant disponibles n'avaient pas permis de suivre les dernières manoeuvres d'inclinaison de la constellation A-train réalisées au printemps 2009. Cependant les mesures étaient encore en phase avec celles des autres capteurs. Sur la nouvelle orbite atteinte par PARASOL, cette quasi-simultanéité des mesures ne se reproduira désormais qu'à intervalles réguliers et pendant une durée limitée à quelques jours. Le CNES a décidé de positionner PARASOL un peu en dessous du A-train pour minimiser les risques en cas de défaillance du satellite et garantir ainsi la sécurité des autres satellites de la constellation. En effet, initialement prévu pour 2 ans, PARASOL atteindra ses 5 ans de mission nominale en mars 2010. PARASOL fêtera donc en solitaire son cinquième anniversaire en orbite le 18 décembre prochain mais poursuit néanmoins normalement sa mission d'observation des nuages et des aérosols.

After collecting observations synchronous with the other satellites from the A-Train for almost 5 years, PARASOL was moved to a lower orbit (3.9 km beneath) at 12:48 UT on December 2, 2009. The maneuver was performed by the CNES flight operations teams. The microsatellite PARASOL had joined the A-Train constellation in early February 2005. PARASOL orbit tracks have been slowly drifting eastward these past few months, due to insufficient fuel supplies that prevented PARASOL to be part of the last inclination maneuver performed by the other A-Train satellites in Spring 2009. However, observations were still in phase with the other sensors. On the new orbit, observations from PARASOL will no longer be simultaneous with the other sensors, except for only a few days at regular intervals. CNES's decision to position PARASOL to a lower orbit was motivated by safety reasons to minimize the risk of collision, should PARASOL begin to fail. While the expected duration of the PARASOL mission was 2 years, it will reach 5 years in March 2010. On December 18, 2009, PARASOL will celebrate its 5th anniversary in orbit, alone, yet pursuing its mission of observation of clouds and aerosols.

ICARE Workshop
on Atmospheric Processes and Remote Sensing
8-9 October 2009

ICARE's Users Committee and Chief Scientist organized a meeting on aerosol-cloud-radiation interactions and water cycle. The meeting took place on 8-9 October 2009 at the University Paris 6. The main objective of the meeting was to present the current status of remote sensing of atmospheric variables and processes followed by round table discussions. Four specific topics were discussed: climatic variables and trends, boundary layer, tropics, and convection in the upper troposphere/lower stratosphere.

+ Read more (in French)

April 2009: ICARE's Wiki is now available!

ICARE's Wiki is dedicated to ICARE users for sharing any useful information related to ICARE services. Anybody can read those pages, but you will have to register and log to ICARE wiki if you want to add or modify any page (even if you are already registered to ICARE general services).

+ Access ICARE's Wiki

PARASOL: 4 years in orbit

In March 2009, ICARE celebrates the 4th anniversary of PARASOL successful operations. PARASOL is a microsatellite launched by CNES on December 18, 2004. It carries a wide-field imaging radiometer/polarimeter called POLDER (Polarization and Directionality of the Earth's Reflectances). PARASOL is part of the A-Train constellation, and contributes to an overall strategy to observe clouds and aerosols from multiple sensors on the same orbit. Originally scheduled to last 2 years, the mission was reconducted indefinitely, in consideration of the instrument good performance and scientific value. The ICARE Data and Services Center generates derived cloud and aerosol science products routinely, usually within 24-48 hours of data acquisition. Science products have been operationally produced and distributed since March 2005, at the end of the satellite commissioning phase. Other than a few scattered incidents, PARASOL did not experience any major problem, and only very few downtimes occurred. Over 4 years's worth of PARASOL data are now available in the ICARE archive.

+ Read more