SPOT4(Take5)

SPOT4(Take5) data downloads statistics

=> Three and a half months after the first release of SPOT4 (Take5) products, we can draw a first analysis of the SPOT4(Take5) data downloads (from THEIA distribution website : http://spirit.cnes.fr/take5/)  We have also obtained a ranking of the 45 sites versus the number of downloads, and notice that all 45 sites where at least […]

SPOT4(Take5) aerosol optical thickness validation results

=> We are currently preparing a data reprocessing of all SPOT4 (Take5) data, to be released before the end of 2013. For this, I tested several aerosol models and compiled all the validation results for our multi-temporal Aerosol Optical Thickness (AOT) estimation method named MACCS. Our estimates are compared to AERONET in-situ AOT measurements.The MACCS […]

Validation des épaiseurs optiques d’aérosols obtenues pour SPOT4(Take5)

=>Nous sommes en train de préparer un retraitement des données SPOT4 (Take5) pour la fin de l’année. Pour en choisir les paramètres, j’ai compilé tous les résultats de validation des épaisseurs optiques mesurées par notre méthode MACCS, en les comparant avec celles mesurées par le réseau Aeronet. Dans la méthode MACCS appliquée à SPOT4(Take5), en […]

A new version of the SPOT4(Take5) products is available.

=> The CNES teams of the THEIA Land Data Center have reprocessed the SPOT4 (Take5) data, in order to take into account a large number of images that were not processed in the first place, because some data had not been yet received or because their processing had failed due to a few little bugs. The […]

How to estimate Aerosol Optical Thickness

=> Caution ! This post contains formulas ! Aerosols play a great role in the atmospheric effects. Aerosols are particles suspended in the atmosphere, which can be of several types: sand or dust, soot from combustion, sulfates or sea salt, surrounded by water… Their size ranges between 0.1 micron and a few microns, depending on […]

Nous jouerons Take5 jusqu’à la fête de la musique !

=>La fin de l’expérience SPOT4(Take5) était initialement prévue le 28 mai, mais le CNES a accepté de prolonger l’expérience de près d’un mois, jusqu’à la fin du printemps. SPOT4 prendra donc ses dernières images autour du 21 Juin. Cette prolongation nous permettra d’observer, en France, la fin du cycle des cultures d’hiver et le début des […]

We will play Take5 until the end of Spring !

=> The end of SPOT4 (Take5) experiment was initially planned the 28th of May, but CNES just decided to extend it until the end of Spring.  The last SPOT4 images should be acquired around June the 21st. In France, and in many other countries, June 21st is the « Music Day » : we will be playing […]

SPOT4(Take5) : Cloud statistics after one month

=> We have now received all the L1A images of the SPOT4(Take5) experiment taken between January the 31st and March the 10th, for which at least some part of the surface is visible. We ortho-rectify these images to obtain level 1C products, but sometimes, the cloud cover is still too high to process the image. […]

SPOT4 (Take5) : statistiques de couverture nuageuse sur un mois

=>Nous avons reçu d’Astrium Geo toutes les images de niveau 1A de l’expérience SPOT4(Take5), acquises entre le 31/01/2013 et le 10/03/2013, qui ne sont pas entièrement couvertes de nuages. Nous ortho-rectifions ces images pour obtenir des produits de Niveau 1C. Il arrive cependant que la couverture nuageuse soit trop importante pour pouvoir fabriquer un produit […]

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