A partir des produits neige Theia, j’ai calculé la durée d’enneigement entre le 1er juin et le 31 août à 20 m de résolution spatiale pour chaque année depuis 2017 dans les zones cœurs des quatre Parcs Nationaux français de haute montagne (Pyrénées, Vanoise, Écrins, Mercantour). A titre d’illustration voici la comparaison entre l’été 2022 […]
=> The applications of interferometric techniques on radar images are currently developing in many fields. Being able to easily process and plot radar images, interferograms or time series of interferograms with a tool and data that are free and available without being a specialist is an important issue for scientists or companies that do not […]
Because the first images were partly cloudy, the Pléiades 1A and 1B satellites (CNES/Airbus) continued to acquire images over Kyrgyzstan and a cloud-free 0.7-m stereoscopic pair was acquired 16 July 2022. We could also obtain a 1.5 m SPOT7 stereoscopic pair from the Airbus DS archive thanks to the Dinamis initiative. The latter was taken […]
Our let-it-snow (LIS) processor computes the extent of the snow cover from Sentinel-2 surface reflectance (level 2 products). However, it can also compute multi-temporal composites (level 3 products) such as the snow cover duration, snow onset and snow melt out date from a time series of snow cover maps with a cloud mask. Aurore Dupuis […]
Collard et al. (2022) have shown that Sentinel-2 can be used to estimate the wave spectrum in the presence sea ice. The waves tilt the sea ice surface and therefore modulate the reflected radiation that is received by Sentinel-2 sensor. The wave spectrum extracted from the image can even be used to invert the wave […]
Last week, Simon Gascoin and I spent quite some time working on the Marmolada event. Just a week-end to rest and Twitter reminded us Monday morning that this summer 2022 was special for glaciers. Not only are they out of balance with the climate and will probably suffer one of their most negative mass balance […]
The deadly Marmolada glacier collapse happened on 3 July 2022. On 6 July 2022, Pléiades 1B (CNES, Airbus DS) acquired a clear-sky stereo pair of the area. From these images we could estimate a detached volume of ice of 65’000 ± 10’000 cubic meters. First, we generated a digital elevation model (DEM) from Pléiades stereo […]
Alors que les bassines se développent en France pour stocker l’eau en particulier en Pays de la Loire, elles sont aussi utilisées au Maroc dans un environnement bien plus aride. Dans la région désertique entre Errachidia et Boudnib, près de la frontière algérienne, l’apparition de ces piscines géantes a transformé le paysage. L’eau est prélevée […]
=> In our a priori definition of Sentinel-HR mission, we had included an option to observe the 3D topography at a high resolution, with a moderate accuracy ambition (lower than that offered by the CO3D satellite, as shown in the table below), but globally and with a systematic revisit. But our mission advisory group insisted, […]