This post intends to answer a question about Sentinel-HR, that we have had quite often inside or outside CNES : Securing continuity in a critical timeseries requires user community foresight, Programme justification, 10 yrs Agency prep, and finances. Whilst Sentinel-HR may well be an excellent/valid idea, I’m left asking why certain Copernicus contributing missions couldn’t […]
=> Si vous travaillez avec des produits Sentinel2, vous avez probablement entendu dire que le nouveau traitement géométrique de l’ESA est actif depuis le 1er avril 2021. Ce nouveau traitement se base sur l’affinage des paramètres de prise de vue par rapport à un ensemble d’images de reference (Global Reference Image, GRI), et doit diminuer l’erreur […]
=> If you are working with Sentinel2 products, you probably heard that ESA new geometric processing is active since 1st of April 2021. This new processing, based on the geometric refinement of viewing parameters with respect to a Global Reference Image (GRI), should bring absolute location error from 11 meters (95.5% of products) to better […]
The distribution of MAJA L2A processor, as an executable software, started in april 1997, but we started counting the number of downloads only since October 2017. The cumulative number of downloads just reached 2000 on April the 2nd 2021. It is on average 1.56 downloads per day, and more than 2 downloads per work day […]
=> Here is a frequently asked question : I noticed, in such L2A product processed by MAJA, that some pixels had negative reflectances, is it normal ? No, it should not happen, but the fact it happens is not entirely surprising, I will explain it below. Unlike negative reflectances, reflectances greater than one can exist, […]
=> Voici une question que je reçois assez fréquemment : J’ai remarqué dans (tel produit L2A Sentinel-2 corrigé des effets atmosphériques par MAJA) des réflectances négatives ou égales à zéro. Est-ce normal ? Non, ce n’est pas normal, mais ce n’est pas totalement surprenant non plus. Contrairement aux réflectances négatives, qui ne devraient pas exister, […]
In the last few months, several papers on Sentinel-2 cloud detection have been published by MDPI remote sensing journal. We found large errors or shortcomings on two of these papers, that should not have been allowed by the reviewers or editors. The third one is much better, even if we disagree with one of its […]
Sur une image Pléiades acquise le 15 janvier, Etienne a remarqué une fracture qui traverse une bonne partie de la langue du glacier de l’Astrolabe auprès de la base Dumont-d’Urville en Antarctique. On peut reconstituer l’ouverture de cette crevasse à partir d’une série d’images Sentinel-1 (une année complète de janvier 2020 à janvier 2021) D’après […]
=> The Space Climate Observatory (SCO) is an international initiative of the One Planet Summit, launched in June 2019, which is also a French initiative. The SCO brings together several space agencies around the world and international organizations (UNDP, ESA, UNEP). It aims at developping projects for local decision-makers to help them adapt to climate […]