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 !
Les images suivantes montrent qu'au cours du mois de janvier de la neige naturelle a finalement recouvert le site...
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.
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.
TIROS-1 weather satellite was launched by NASA on 01 April 1960. It took the first weather satellite picture on 02 April 1960 , and also the real first weather satellite picture on 01 April 1960 .
On 02 April 1960 it took what I believe is the first publicly available satellite picture of the snow cover in the Alps (picture 1 below). On 13 May 1960 it captured a stunning view of the snow cover over the High Mountain Asia, including the Himalayas, Hindu Kush, Pamir and Karakoram ranges. These pictures are shown in the TIROS-1 final report .
Villarrica volcano is one of the most active volcanoes in the Chilean Andes. A colleague of mine (Esteban Alonso) told me that last week he went ski touring up there and when he reached the summit he could see the bubbling lava in the bottom of the crater, and could even feel its heat...
Yesterday Theia shifted into high gear and released 1300 snow products!. These products correspond to 13 Sentinel-2 tiles covering the Western Alps (France/Italy/Switzerland), the Pyrenees (France/Spain) and the Hight Atlas (Morocco).
Hier Theia est passé à la vitesse supérieure et a mis à disposition 1300 produits neige ! Ces produits correpondent aux 13 tuiles Sentinel-2 qui couvrent les Alpes Occidentales (France/Italie/Suisse), les Pyrénées (France/Espagne) et le Haut-Atlas (Maroc).
This was made possible thanks to the great work of Dominique Clesse, Joëlle Donadieu, Céline L'Helguen, Arnaud Selle and Simon Baillarin at CNES. Merci à eux !
Nous sommes heureux d'annoncer que Theia a mis en ligne 93 produits neige faits à partir de Sentinel-2. Ces produits correspondent à 6 tuiles qui couvrent une partie des Alpes, des Pyrénées et de l'Atlas pour une période comprise entre juillet et novembre 2016. La production opérationnelle devrait débuter cet automne (c'est-à-dire au fil de l'eau), et couvrira une surface plus grande. Nous essaierons aussi d'améliorer les produits grâce aux retours des utilisateurs.
Série temporelle de produits neige pour la tuile 30TYN (Pyrénées)
We are pleased to announce that Theia has put online 93 Sentinel-2 snow products, corresponding to 6 tiles in the Alps, Pyrenees, and Atlas mountains between July 2016 to November 2016. 300 more products should be available next week. The operational production should start in autumn 2017 (i.e. near real time), and will cover a larger area. We will also strive to improve the products based on the users feedbacks!
Time series of available products for tile 30TYN (Pyrenees)
Sentinel-2A was launched on 23-July-2015 but the routine operations started in July 2016 after the ramp-up phase . Now with the onset of the austral summer, the first Sentinel-2A images of Antarctica are getting available (except for Dome C, which is a calibration site).