=> The LANDSAT-8 and SENTINEL-2 satellites have a spectral band centered on the 1.38µm wavelength, which is designed to allow the detection of high altitude clouds. This spectral band corresponds to a strong absorption band of water vapour. its absorption is so strong that a photon emitted by the sun in this wavelength has nearly […]
In a classical Hollywood thriller, in which the hero nearly dies several times, a last sequence of the film is usually dedicated to the happy ending with a swinging music. The same happens with the SPOT5 (Take5) story : after several periods with very little hopes of success, the SPOT5 (TAKE5) experiment is finally close […]
=> Sentinel-2 orbits The Sentinel-2 orbit was set so that the swaths observed by the satellite have a little overlap at the equator. The width of the overlap increases quickly at higher latitudes. For instance, at France latitude (45 degrees), about half of the surface will be observed twice per satellite cycle, from two adjacent […]
Rappel : Le CNES invite tous les utilisateurs des données SPOT4 (Take5) à un atelier de deux jours dans les locaux du CNES à Toulouse, du 18 au 19 novembre 2014. Un an et demi après l’expérience SPOT (Take5), et un an après la première réunion des utilisateurs, ce sera l’occasion de faire le point […]
=> Those who know me know that I work with Linux and that I like to use free softwares, even if it is not always easy at CNES where everything is around windows :-(. But before I started this blog, I had never contributed with free software. A few months ago, I published here two […]
CNES just gave a green light to go on with the studies to repeat the Take5 experiment with SPOT5. These studies will determine the exact cost of the experiment and see if it fits with what could be available, accounting for ESA’s help. If everything goes well, the experiment would start around April 2015, until […]
A partir de maintenant, le pôle THEIA mettra en ligne tous les mois un lot de données LANDSAT 8 supplémentaire, récemment acquises au dessus de la France. Le dernier lot publié va jusqu’au 31 mai 2014. Les données sont toujours à la même adresse : http://spirit.cnes.fr/resto/Landsat/Nous vous conseillons toujours la lecture de la description de […]
C’est fait, les données Landsat 5 et 7 au niveau 2A sont en ligne sur le serveur de THEIA. Elles sont accessibles depuis cette adresse http://spirit.cnes.fr/resto/Landsat/ Nous vous conseillons aussi la lecture du guide d’utilisation du serveur de distribution, et la description de leur traitement. The LANDSAT 5 and 7 data at level 2A are […]
=> As we are working to set-up a new Take5 experiment with SPOT5, here are some explanations of how it is possible to change the repeat cycle of a satellite from 26 days to 5 days, by just changing the satellite altitude by a couple of kilometres. There is nothing complicated behind that, just some […]