40 research outputs found
A gradient-like variational Bayesian approach for joint image super-resolution and source separation, application to astrophysical map-making
International audienc
Retrieval of vertical constituents and temperature profiles from passive sub-millimeter wave limb observations of the Martian atmosphere: a feasibility study
The investigation of the Martian atmosphere is of key importance for an understanding of the planets present and past. Passive limb observations of thermal radiation at submillimeter wavelengths in the 320â350-GHz range by use of a state-of-the-art satellite receiver on a low Mars orbit allow important parameters such as the mixing ratios of H2O, HDO, 12CO, 13CO, O3, and H2O2 as well as the thermal profile to be retrieved with high precision and unprecedented vertical range and resolution, providing valuable information for better understanding of the planetâs water cycle, atmospheric dynamics, and photochemistry. The feasibility of these kinds of measurement is demonstrated by means of model simulations based on realistic atmospheric, spectroscopic, and instrumental parameters. Temperature can be retrieved to âŒ90 km with half-scale height vertical resolution from single-scan measurements of emission lines of the long-lived species 12CO and 13CO. The global water-vapor distribution can be measured even under dry or wet conditions with good vertical resolution from the surface to âŒ45 km, and simultaneous observations of HDO allow useful information on the D/H ratio up to an altitude of âŒ30 km to be derived. The sensitivity of the limb-sounding technique also permits information on the photochemically important minor species O3 and H2O2 to be obtained. It is shown that spectral averaging may improve precision, altitude range, and resolution of the retrieved profiles. Other frequency bands are explored, and the 435â465-GHz range is suggested as a possible alternative to the 320â350-GHz range
Analysis of Polarimetric GNSS-R Airborne Data as a Function of Land Use
International audienceThe objective of this study is to analyze global navigation satellite system reflectometry (GNSS-R) data variations as a function of land cover using airborne measurements obtained with the global navigation satellite system reflectometry instrument (GLORI), which is a polarimetric instrument. GNSS-R measurements were acquired at the agricultural Urgell site in Spain in July 2021. In situ measurements describing the soil and vegetation properties were then obtained simultaneously with flight measurements. The behavior of the observable copolarization [rightâright (RR)] reflectivity ÎRR and the cross-polarization [rightâleft (RL)] reflectivity ÎRL as a function of land use is discussed. The distribution of coherent and incoherent components in the reflected power is estimated for different types of land cover
Bonnes pratiques en Ă©coconception de service numĂ©rique: Incontournables pour diminuer de façon drastique les GES, elles font lâobjet dâun guide. On en dĂ©couvre la genĂšse.
National audienceEcoInfo, un collectif qui comprend des ingĂ©nieurs, des chercheurs et des enseignants-chercheurs des secteurs de la recherche et de lâenseignement supĂ©rieur, propose notamment la production dâun guide de Bonnes pratiques en Ă©coconception de service numĂ©rique, dont la derniĂšre version a Ă©tĂ© publiĂ©e en mai 2023. On vous en prĂ©sente ici les grandes lignes
Je code: les bonnes pratiques en éco-conception de service numérique à destination des développeurs de logiciels
Following the booklets on good practices in software development that were produced by the GT-Patri of the DevLOG network (in conjunction with the DRE CNRS), the french GDS EcoInfo has produced a booklet on good practices in digital service eco-design for software developers.This booklet is a complement to the 3 booklets of good practices related to software development proposed by the network of actors of software development within the french Education and Research: DevLOG.This project is dedicated to good practices in terms of eco-design of digital services that allow to apprehend, understand and reduce the environmental impact of digital technology.macroAfter explaining the general context in the first sheet, a second sheet ("But Why?") highlights the need to integrate an environmental dimension into our digital service designs, and consequently into our software developments. The third sheet ("When?") reminds us of the stages in the life cycle of a digital service and introduces the good practice sheets that correspond to the different stages: "Before", "During" and "After", bearing in mind that development is often iterative, and the boundaries between the different stages are permeable.At the end of the booklet, you will find a specific sheet on eco-design practices for scientific computing, as well as sheets on development on mobile platforms, for the web and on hardware accelerators.Cette plaquette est un complément aux 3 plaquettes de bonnes pratiques liées au développement logiciel proposées par le réseau des acteurs du DEVeloppement LOGiciel au sein de l'Enseignement Supérieur et de la Recherche : DevLOG.Ce volet est dédié aux bonnes pratiques en termes d'écoconception de service numérique qui permettent d'appréhender, de comprendre et de réduire l'impact environnemental du numérique.AprÚs avoir explicité le contexte général dans une premiÚre fiche, une seconde fiche ("Mais pourquoi ?") met en évidence la nécessité d'intégrer une dimension environnementale dans nos conceptions de service numérique, et par conséquent dans nos développements de logiciels. La troisiÚme fiche ("Quand ?") rappelle les étapes du cycle de vie d'un service numérique pour introduire les fiches de bonnes pratiques qui correspondent aux différentes étapes : "Avant", "Pendant" et "AprÚs", en gardant à l'esprit que le développement est souvent itératif, et les frontiÚres entre les différentes étapes sont perméables.Vous trouverez à la fin de la plaquette une fiche spécifique sur les bonnes pratiques d'écoconception pour le calcul scientifique, ainsi que des fiches sur le développement sur plateforme mobile, pour le web et sur accélérateur
Bonnes pratiques en Ă©coconception de service numĂ©rique: Incontournables pour diminuer de façon drastique les GES, elles font lâobjet dâun guide. On en dĂ©couvre la genĂšse.
National audienceEcoInfo, un collectif qui comprend des ingĂ©nieurs, des chercheurs et des enseignants-chercheurs des secteurs de la recherche et de lâenseignement supĂ©rieur, propose notamment la production dâun guide de Bonnes pratiques en Ă©coconception de service numĂ©rique, dont la derniĂšre version a Ă©tĂ© publiĂ©e en mai 2023. On vous en prĂ©sente ici les grandes lignes