=> L’acquisition de mesures sur le terrain se passe rarement sans quelques petits aléas. Dans le cas de notre nouvelle station ROSAS fraîchement installée il y a un mois, l’aléa a malheureusement pris la forme d’un engin agricole venu percuter le mât lors d’un travail du sol le 15 avril dernier. La base du mât […]
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, […]
These space engineers are fast and efficient ! Just a week after our ROSAS station in Lamasquère was erected, we already have the first BRDF measurements, the producing of which required also the processing of calibration sequences. This was done thanks to our colleagues at CNES from the service in charge of measurement physics […]
=> At last! We announced it in March 2020, and here it is, one year later! From lock-downs to constraints related to crops grow stages or soil wetness, we have been forced to postpone the operations several times. And finally, the ROSAS* Lamasquère (South-Western France) station sent its very first measurements on March 17, 2021. […]
=> Enfin ! Nous vous l’avions annoncé en mars 2020, la voici opérationnelle un an plus tard. De confinements en contraintes liées à l’état des cultures et du sol, nous avons été obligé de repousser les opérations à de multiples reprises. Et finalement, la station ROSAS* de Lamasquère (Haute-Garonne, France) aura fait ses premières mesures […]
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 […]
=> Do we need to remind you of all the collateral damage linked to deforestation or the eco-system services that forests provide ? We have already talked about these in this blog (here and there too). Yet forests are disappearing at an alarming rate. Between 1990 and 2020, an area of forest equal to more […]