Validation

A new article on the validation of MAJA’s Sentinel-2 surface reflectances

Whether you are a user of the atmospheric correction processor MAJA or THEIA’s Sentinel-2 Level 2 products, you will probably be interested to read our new article on the validation of MAJA Sentinel-2 surface reflectances. The article is published in open access in Remote Sensing : Colin, J.; Hagolle, O.; Landier, L.; Coustance, S.; Kettig, […]

22.05.2023

First validation results with the Lamasquère ROSAS instrument

=> Following its installation in March 2021, our new ROSAS device at Lamasquère has produced a first series of acquisitions over a complete maize crop cycle. The ROSAS system is based on the use of a multi-spectral photometer to carry out angular and spectral measurements of both incident and reflected radiation from the surface. The […]

14.12.2021

Premiers résultats de validation du site ROSAS de Lamasquère

=> Suite à sa mise en place en mars 2021, notre nouveau dispositif ROSAS de Lamasquère a produit une première série d’acquisitions sur un cycle complet de culture de maïs. Le dispositif ROSAS repose sur l’utilisation d’un photomètre multi-spectral pour non seulement réaliser des mesures angulaires et spectrales du rayonnement incident, mais aussi du rayonnement […]

Notre nouveau travail, jardiniers !

=> Après qu’un premier tracteur s’est approché trop près de notre station ROSAS, le suivant est passé un peu trop loin. Même si on n’est jamais contents, c’est bien mieux comme ça ! Ce tracteur a semé le maïs sur la parcelle sur laquelle nous avons construit la station. S’il est acceptable de laisser un […]

05.06.2021

Our new job: gardeners !

=> After a first tractor came too close from our ROSAS station, the next one passed by a little too far. Even if we’re never satisfied, it is much better ! This tractor sowed the maize on the plot on which we have built the station.  If it is acceptable to leave a two meter circle […]

04.06.2021

Premiers retours sur le nouveau traitement géométrique Sentinel2

=> 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 […]

05.05.2021

A first peek at new Sentinel2 geometric processing

=> 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 […]

Several issues found in recent papers on cloud detection published in MDPI remote sensing

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 […]

11.03.2021

Soon a new ROSAS station for measuring bi-directional reflectance at Lamasquère, South of France

=> The L2 products from the Maja chain are regularly evaluated for their quality, whether in terms of cloud detection, optical thickness estimation or surface reflectance estimation. While the validation of the cloud masks is essentially based on the tedious creation of sets of controls (manual or semi-automatic), the estimation of the optical properties of […]

18.03.2020

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