Sentinel-2

Patagonian skies are not cloudy anymore

« The most usual weather in these latitudes is a fresh wind between north west and south west with a cloudy overcast sky » – Phillip Parker King, Sailing Directions for the Coasts of Eastern and Western Patagonia (1832). Patagonia is a beautiful place to visit but campers know that the weather is extremely variable and the […]

Sentinel-2A captures a giant ice avalanche in Tibet

The Nature News website reported yesterday on a massive ice avalanche that happened in Rutog, Tibet, on 17 July 2016. This ice avalanche killed 9 people and may be one the largest ever observed. The ice and rock mixture spread over 6 km from the collapse point up to the Aru Co lake shoreline.

First Sentinel-2 snow map

=> In the framework of the THEIA land data center, we have developed a simple but robust method to map the snow cover from Sentinel-2-like level 2A products. This code was tested with SPOT-4 Take-5 and Landsat-8 series, but it remained to adapt it so that it can run on real Sentinel-2 images! This is […]

Premier masque de neige Sentinel-2

=>Dans le cadre du Centre d’expertise scientifique THEIA « surface enneigée » nous avons développé une méthode simple et robuste pour détecter la neige à haute-resolution à partir des produits de niveau 2A de type Sentinel-2. Ce code a été testé sur des séries SPOT-4 Take-5 et Landsat-8, mais il restait à l’adapter pour qu’il puisse tourner […]

SAT-IRR: Satellite for Irrigation Scheduling

=> Following the irrigation scheduling experiment in Morocco during the SPOT4-Take5 experiment (Le Page et al, 2014), a Web tool owing to help the irrigation decision making is under development (http://osr-cesbio.ups-tlse.fr/Satirr). The tool is functional on three Landsat8 tiles: Marrakech in Morocco, Kairouan in Tunisia, Toulouse, France. As the tool is addressing irrigators, the idea is […]

2015

=> Dear reader,  may 2015 bring you health and happyness !2015 should be a great year for the time series of optical images at a high resolution, with the launch of Sentinel 2A in Mat, in less than four months ! We have been waiting for it for so long that we can hardly believe […]

2015

=>Chers lecteurs de ce blog, que cette année 2015 vous apporte joie et santé  !L’année 2015 sera une grande année pour les séries temporelles optiques à haute résolution, avec le lancement de Sentinel-2A début mai, dans moins de quatre mois ! Nous attendons ce satellite depuis si longtemps qu’il est difficile de croire que cette […]

Comparison of Level 3A compositing methods

=> As said in a previous post, we are testing various methods of level 3A production, using SPOT4 (Take 5). The Theia Land Data Center will the use these methods to process Sentinel 2 data. In case you did not click on the link above, let’s recall that the level 3A products are monthly composite […]

How to estimate Aerosol Optical Thickness

=> Caution ! This post contains formulas ! Aerosols play a great role in the atmospheric effects. Aerosols are particles suspended in the atmosphere, which can be of several types: sand or dust, soot from combustion, sulfates or sea salt, surrounded by water… Their size ranges between 0.1 micron and a few microns, depending on […]

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