MAJA presentation at the Recent Advances in Quantitative Remote Sensing symposium, fifth edition

I just came back from Valencia, where I attended the fifth edition of the  Recent Advances in Quantitative Remote Sensing Symposium. It is one of my favourites, thanks to an amazing team of organizers led by Jose Sobrino. It is a unique symposium, because it has only one session  where you can even see opticians listen to radarists, or passive microwaves experts share ideas with active microwave experts ! Every three years, it is a way to gather quickly a good sense of the advances in each domain of remote sensing, over lands mainly. Next RAQRS will happen in 2020 in Valencia, and no doubt I'll be there, and not only for the delicious coffee breaks or for the giant paella.

 

Of course, my talk, available here or visible below, was about Sentinel-2 L2A products, including cloud detection and atmospheric correction. This time, I focused on product validation and provided a lot of validation results obtained by our little team at CNES and CESBIO, with special thanks to Camille Desjardins (CNES) and Bastien Rouquié (CESBIO) and Magdalena Main-Knorn (DLR). I also provided a comparison of MAJA and Sen2cor for various criteria that all show the benefits of using multi-temporal information, as done in MAJA. Despite all that, and although these results were perfectly known by ESA, ESA decided to stick with Sen2cor in their production, supposed to be global next year. The slides explain how this decision was made.

 

Anyway, as you probably know, you can access MAJA products from Theia, or you may also download MAJA's executable (if you have a powerful linux computer).

 

 

 

 

Aftermath of Mathew hurricane over Haiti in 2016

Following Simon's publication on Saint Barthelemy island after Hurricane Irma, one of our twitter friends, @Pierre_Markuse, posted a comparison of the South Western part of Haiti, before and after Mathew huricane ravaged it last year, on the 4th of October 2016. As you can see, the whole lands turn brown just after the hurricane. I am really not an expert, so I just can imagine it is caused by the wind cutting branches and trunks and by water run-off taking the lower vegetation away.  I read that 40% or the  forest and 20% of the shrub has been erased. Moreover, the wind and water must have left mud and dust on the remaining leaves, contributing to the brown color.

 

However, what is amazing is that by end of November, vegetation comes back ! My guess is that mud and dust disappear, shrubs and trees start to grow new leaves and the low vegetation grows back  But experts are welcome to explain how it happens exactly, there is a comment section !

 

I have an additional special own interest in displaying this information :  it is a hard test for how our multi-temporal methods included in MAJA to detect clouds, shadows and aerosols can manage such a case. Continue reading

[MUSCATE] 1141 L2A products in a day !

Yesterday, MUSCATE facility at CNES produced 1141 Sentinel-2  L2A products in a day, while the previous record was 762. A few glitches had reduced the production on the previous days, and yesterday allowed us to catch up the back log. At the same time we have started producing data acquired in 2016 for several zones outside Europe and Africa. The total number of L2A products in MUSCATE now amounts to 33071. Congrats and thanks to the development and exploitation teams !

Hier, le centre de traitement MUSCATE au CNES a traité 1141 produits de niveau 2A de Sentinel-2, alors que le record précédent était 762. Quelques petits soucis avaient retardé la production ces derniers jours, et c'est hier que nous avons rattrapé le retard, et en même temps lancé la production des données acquises en 2016 sur un grand nombre de  zones hors Europe et Afrique. Le nombre total de produits de nievau 2A atteint maintenant 33871. Félicitations et un grand merci aux équipes de développement et d'exploitation !

 

Les Sentinels témoins de la déforestation en Amazonie

Le Monde.fr a publié un reportage frappant "Au Brésil, avec les policiers qui luttent contre la déforestation de l’Amazonie". Le journaliste et photographe Bruno Kelly a suivi les agents de l’institut pour l’environnement et les ressources naturelles renouvelables (Ibama) dans les environs d'Apui, une petite localité isolée au sud de l'état d'Amazonas. Il écrit que "le chef de la police reconnaît que contrôler avec 1 300 agents une zone de la taille de l’Europe occidentale est une tâche pour le moins difficile".
 
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Vavilov Glacier in 2016 and 2017

Back from a long summer break, I needed to find something else to do than just catching up with emails... Luckily, the organizers of the 2017 International Glaciology Society meeting in Boulder tweeted this animation of the Vavilov Glacier (October Revolution Island, Russian Arctic):


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THEIA distributes L2A Sentinel-2 data over Italy, Switzerland, and most of Alps

Done ! All Sentinel-2 data acquired above Italy, Switzerland and Austrian Alps, and processed at level 2A, are now available on Theia website! The data format is described here. We would be very thankful if users in Italy or Switzerland could help us spread the news among remote sensing users in both countries.

 

The level 2A product provides surface reflectances with a good cloud and shadows mask. The processing is done at CNES, within MUSCATE facility, using the MAJA software, developed by CNES, CESBIO and DLR. The production started with data acquired in December 2016, and will go on in near real time.

 

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An anomaly provisionally prevents real time production in ESA's Sentinel-2 ground segment

That's bad luck, just before the long week-end of the 15th of August, ESA Sentinel-2 ground segment failed and ceased production. This explains why Theia ground segment is not producing in real time anymore.

Pas de chance, le segment sol de Sentinel-2 À L'ESA est tombé en panne juste avant le week-end du 15 août. Ceci explique pourquoi la production de Theia ne s'effectue plus en temps réel.

As a consequence of a ground segment contingency occurred at Matera station, the publication of Sentinel-2 products in the data hubs is temporarily interrupted as of today 11 August. The anomaly is under investigation and the data dissemination is expected to resume by mid of next week.

NASA selected CESBIO's land cover map of France as "image of the day"

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It is a well deserved recognition for the land cover product developed at CESBIO : NASA's earth observatory blog dedicated its "image of the day" blog post for the 15th of August to this product.

 

This work was done in the framework of Theia, using iota2 free software also developed at CESBIO. Thanks to the information conveyed by time series,iota2 is a fully automatic processor.

Jordi Inglada's team first published in 2015 a land cover map based on LANDSAT 8 data acquired in 2014, with a 30m resolution.This production was followed, in 2017 by a new map, based on Sentinel-2 data, acquired in 2016, at 10m resolution.

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La NASA choisit le produit d'occupation des sols OSO du CESBIO comme "image du jour "

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C'est une reconnaissance bien méritée pour le produit d'occupation des sols OSO développé et produit au CESBIO : le blog "earthobservatory" de la NASA a consacré son article "image du jour" du 15 août à ce produit.

 

Ce travail a été conduit dans le cadre de Theia, avec le logiciel libre iota2 développé au CESBIO. Grâce à l'utilisation de toute l'information contenue dans les séries temporelles  d'images, la chaîne iota2 arrive à fournir un résultat de grande qualité, tout en étant complètement automatique.

 

L'équipe de Jordi Inglada a publié une première carte en 2015, basée sur les données LANDSAT 8 acquises en 2015, avec une résolution de 30m. Cette production a été suivie, début 2017, d'une carte basée sur les données Sentinel-2, acquises en 2016, cette fois à une résolution de 10m.

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