Venµs captured the orange snow in the Pyrenees

Theia just published the first Venµs images today, including a beautiful view of the Pyrenees. Once you have dezipped/untared/unzipped the files you can make a true color composite using the command:

gdal_translate -b 7 -b 4 -b 3 -scale 0 300 0 255 -ot byte VE_VM01_VSC_PDTIMG_L1VALD_ES_LTERA_20180419.DBL.TIF myColorCompo.tif

I tend to focus on the snow so I stretched the colors between reflectances 0-1000 instead of 0-300:

gdal_translate -b 7 -b 4 -b 3 -scale 0 1000 0 255 -ot byte VE_VM01_VSC_PDTIMG_L1VALD_ES_LTERA_20180419.DBL.TIF mySnowColorCompo.tif

First, I was a bit puzzled by the orange shade in the northern part of the image. We inspected carefully the image with Olivier because at this stage radiometric calibration issues are still possible..
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Enneigement au 1er avril 2018 dans les Pyrénées

Le 1er avril est le moment privilégié par les hydrologues pour caractériser le potentiel hydrologique du manteau neigeux. Dans le cadre de l'OPCC [1] nous avons compilé différents indicateurs [2] :

 

 

  • L'équivalent en eau du manteau neigeux dans les sous-bassins pyrénéens du bassin de l'Ebre est calculé par la Confederación Hidrográfica del Ebro (agence de bassin) à partir d'observations MODIS, des données météorologiques, et un modèle de type "degré-jour" (la fonte est proportionnelle à la température de l'air).

 

https://pbs.twimg.com/media/DZ4_0wkXkAELrmc.jpg

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La neige de Pyeongchang

Connaissiez-vous ce dicton coréen "On n'est jamais trop prudent" ?

 

Voici une série d'images Sentinel-2 près du site olympique de Pyeongchang. On voit de la neige artificielle apparaître dès le mois de novembre !

 

neige Pyeongchang

 

Les images suivantes montrent qu'au cours du mois de janvier de la neige naturelle a finalement recouvert le site...

The operational production of the Theia Snow collection has started

Great news, we can announce that the operational production of the Theia snow collection has started well. It means that maps of the snow cover area are now constantly added to the Theia portal. These maps are automatically generated from Sentinel-2 observations and have a spatial resolution of 20 m. The Snow collection will progressively cover most mountain regions in west Europe, but also the Atlas in Morocco, eastern Canada... The Snow collection can be freely downloaded from http://theia.cnes.fr by any registered user.

 
Today's front page of the Theia website featured this nice example in Sierra de Ancares (western end of the Cantabrian Mountains, Spain). In the southeast, snow was also detected on the Montes Aquilanos, including the small ski resort El Morredero. The image was captured yesterday! It illustrates well the value of multispectral imagery to discriminate the snow cover from the clouds. There is a cloud which looks alike snow but it is actually a valley fog confined by local topography.
 

Theia Sentinel-2 level 2A and snow product in the region de los Ancares, Spain. Image captured by Sentinel-2A on 30 Jan 2018.

Theia Sentinel-2 level 2A and snow product in the region de los Ancares, Spain. Image captured by Sentinel-2A on 30 Jan 2018.


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Ceci n'est pas un aéroport

Sentinel-2 a acquis cette belle image de la campagne autour de Notre-Dame-des-Landes le 17 janvier 2018, le jour même où le Premier ministre annonçait que le projet d'aéroport du Grand Ouest était abandonné. Pour fêter l'occasion le ciel breton s'était éclairci !

Image Sentinel-2 de Notre-Dame-des-Landes. La zone d'aménagement différé (ZAD) est délimitée en rouge (polygone téléchargeable sur data.gouv.fr).

Canigou 3D

Lo Canigó és una magnòlia immensa
que en un rebrot del Pirineu se bada
- Jacint Verdaguer i Santaló

 

The Canigó is an immense magnolia
that blooms in an offshoot of the Pyrenees

 

3D view of the Canigou on 19-Dec-2017 (with a fancy tiltshift effect)

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Yesterday's snow cover area in the Pyrenees

Olivier pointed to me that ESA's ground segment, PEPS and MUSCATE were all in really good shape today... And the sky was clear yesterday at the time of the Sentinel-2A acquisition!

So I could download the Level-2A product from theia.cnes.fr, run our let-it-snow processor, start QGIS and here it is: the map of yesterday's snow cover area at 20 m resolution. If you know the region, you might notice that there is currently a big contrast in the snow cover extent between the French and the Spanish Pyrenees. This is due to the blocking of the moist air masses coming from the north.

Snow cover area on 22 Nov 2017. blue: snow, grey: no snow, white: cloud.

Stay tuned! Theia should start to distribute these Sentinel-2 snow products in near real time very soon.