In English
Since spring 2017, we have made the MAJA cloud screening and atmospheric correction processor available for commercial use. A bit later, end of June, the Sen2agri software package, which includes MAJA older version (named MACCS) , was also released to the public. We did not expect a large success, as these two packages are quite […]
In English
I have always wanted to provide an Algorithm Theoretical Basis Document related to MAJA, but never had time, because I always had more urgent things to do. Some papers had been published, allowing MAJA users to get a good idea or the methods we use, but the published articles did not cover all the features […]
Sentinel-2
When we started making tests of the L2A production at MUSCATE with Sentinel-2B data, we considered using a small correction of Sentinel-2B to correct for a eventual bias between the reflectances of each satellite. Such differences were observed by colleagues form CNES, and were comprised between 0 and 2.5%. Finally, we decided not to implement […]
Applications
Le satellite Franco-Israelien Venµs, attendu depuis si longtemps, a été lancé le 2 août 2017. 110 sites dans le monde vont être observés en 2018 et 2019 à 10 m de résolution et avec 12 bandes spectrales. Alors que la plupart des sites ne correspondent qu’à l’emprise d’une scène Venµs (27 à 32 km de […]
CESBIO
=> The main difficulty of the atmospheric correction comes from the determination of the aerosols optical properties: one has to know the optical properties of the aerosol type present in the atmosphere and determine their optical thickness. Using Sentinel-2 data to determine the aerosol type is very complicated, and our MAJA processor, used to generate […]
CESBIO
=>La principale difficulté de la correction atmosphérique réside dans la détermination des propriétés optiques des aérosols : il faut connaître les propriétés optiques du type d’aérosols présent dans l’atmosphère et déterminer leur quantité, symbolisée par l’épaisseur optique. Il est très difficile, à partir des données Sentinel-2, de déterminer le type d’aérosols, et notre chaîne MAJA, […]
Applications
Version française par ici. The land surface models simulate the water and energy fluxes between soil, land cover and atmosphere. Their scopes of application spread from numerical weather prevision to soil water modeling. However, these models are initially conceived to be applied on wide areas. Thus, they use low resolution cover parameters (>1km) derived from mid-resolution […]
Applications
English version right here. Les modèles de surface simulent les échanges d’eau et d’énergie entre le sol, le couvert (végétal ou non) et l’atmosphère. Leurs applications vont de la prévision numérique du temps à la modélisation de l’état hydrique des sols. Cependant, ces modèles, initialement conçus pour simuler de grandes étendues, utilisent des paramètres du couvert […]
Applications
Criticizing is easy, and doing is hard, especially when trying to create a global map of croplands. Some collegues from CESBIO have worked on that subject within the Sen2Agri project, and obtained good resuts, but only at the local or country scale. Finding a method that works everywhere must clearly be much harder.These days, I […]