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Snowmelt and snow sublimation in the Indus basin

The Indus basin has one of the largest irrigation system in the world. Available water resources are abstracted almost entirely, mostly for crop irrigation in Pakistan. The Indus basin is also considered as one of the large basins in Asia with the highest dependence on snowmelt runoff. The contribution of snow and ice melt to […]

27.09.2021

Towards a composite of the most recent clear-sky observations from the Theia Snow collection

We are thinking of a new « live » product which would allow anyone to display the most recent snow observations from Sentinel-2 in a web browser. This service would simply display a composite of the latest Theia Snow products over a given time window (e.g. the past 20 days). This can be easily coded thanks to […]

20.05.2020

Sentinel-2 also sees grassland taxonomic diversity !

Sentinel-2 image time series are widely used to map land cover, see for instance here or here. However, they can be used to extract other relevant information about the observed landscapes. In a recently published article (https://doi.org/10.1016/j.rse.2019.111536), we have used fifteen months of Sentinel optical and radar data to predict taxonomic and functional diversity at […]

20.12.2019

Khumbu icefall in 4D

This video shows all available Venµs images since launch over the Khumbu icefall near Mt Everest (109 images). The images are RGB composites of Level 1C bands 7,4,3 (5 m resolution) that were draped onto the HMA 8m DEM.   How to do that? First download the Venµs images using theia_download.py, extract the region of […]

13.10.2019

Upgrade of let-it-snow to compute the fractional snow cover

In preparation for the next Pan European high resolution snow and ice monitoring service, I have upgraded the let-it-snow (LIS) processor to enable the computation of the fractional snow cover (FSC) within the pixel. So far LIS was only used to compute a « binary snow mask » (in fact ternary: snow, no-snow, cloud). However, the EEA […]

12.09.2019

S1-Tiling, on demand ortho-rectification of Sentinel-1 images on Sentinel-2 grid

=> Sentinel-1 is currently the only system to provide SAR images regularly on all lands on the planet. Access to these time series of images opens an extraordinary range of applications.In order to meet the needs of a large number of users, including our needs, we have created an automatic processing chain to generate « Analysis […]

30.01.2019

S1Tiling : ortho-rectification à la demande des données Sentinel-1 sur la grille Sentinel-2

=>​ Sentinel-1 est actuellement le seul système à fournir des images SAR régulièrement sur toutes les terres de la planète. L’accès à ces séries temporelles d’images ouvre un champ d’application hors du commun. Afin de répondre aux besoins d’un grand nombre d’utilisateurs, dont les nôtres, nous avons créé une chaîne de traitement automatique permettant de […]

Speed-up downloads from PEPS S2 mirror site with peps_download.py

The French Sentinel mirror site, PEPS, has a very clever data management facility. All the products are stored on tapes, with a capacity of several PB, and there is some sort of cache made of disks. The products accessed recently are on disks, while the other products stay on tapes. The storage costs and also […]

23.03.2018

Using NDVI with atmospherically corrected data

NDVI NDVI is by far the most commonly used vegetation index. NDVI was developed in the early seventies (Rouse 1973, Tucker 1979), and widely used with remote sensing in the nineties until now. It is computed from the surface reflectance in the red and near infra-red channels on each side of the red-edge.  where and […]

04.02.2018

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