Prediction of optical communication link availability: real-time observation of cloud patterns using a ground-based thermal infrared camera

The growing demand for high-speed broadband communications with low orbital or geostationary satellites is a major challenge. Using an optical link at 1.55 μm is an advantageous solution which potentially can increase the satellite throughput by a factor 10. Nevertheless, cloud cover is an obstacle for this optical frequency. Such communication requires an innovative management system to optimize the optical link availability between a satellite and several Optical Ground Stations (OGS). The Saint-Exupery Technological Research Institute (France) leads the project ALBS (French acronym for BroadBand Satellite Access). This initiative involving small and medium enterprises, industrial groups and research institutions specialized in aeronautics and space industries, is currently developing various solutions to increase the telecommunication satellite bandwidth. This paper presents the development of a preliminary prediction system preventing the cloud blockage of an optical link between a satellite and a given OGS. An infrared thermal camera continuously observes (night and day) the sky vault. Cloud patterns are observed and classified several times a minute. The impact of the detected clouds on the optical beam (obstruction or not) is determined by the retrieval of the cloud optical depth at the wavelength of communication. This retrieval is based on realistic cloud-modelling on libRadtran. Then, using subsequent images, cloud speed and trajectory are estimated. Cloud blockage over an OGS can then be forecast up to 30 minutes ahead. With this information, the preparation of the new link between the satellite and another OGS under a clear sky can be prepared before the link breaks due to cloud blockage

The OURSE model: Simulating the World Refining Sector to 2030

The development of a model of the World Refining for the POLES model ( Contract n°151559-2009 A08 FR – with the Joint Research Centre Institute for Prospective Technological Studies of Commission of the European Communities) aims to represent the oil product's supply at a world-wide level in a global energy model. The World oil refining industry faces to several challenges such as the increasing oil derivatives demand in the transport sector, the improvement of the specifications of these products, the crude oil availability and the limitation of carbon emissions. An aggregated refining model linked to the POLES energy model has been developed to study these questions. The OURSE (Oil is Used in Refineries to Supply Energy) model is a world-wide aggregated refining model which is designed to simulate the world oil product supply for the POLES (Prospective Outlook for the Long-term Energy System) model. OURSE is able to simulate the impact on the world refining industry of changes in the crude oil supply (in costs and qualities) as well as in the oil product demand (in terms of level, structure and specifications). OURSE also enables to assess the consequences of a carbon emission regulation (caps and taxes) as the adoption of various kinds of alternative fuel policies. More precisely, these impacts are evaluated as regards the world refining structure (investments), but also its balance (production and trade of petroleum products), its pollutant emissions (CO2 and SO2) and its costs (of production, investments, etc.). Simulations for 2030 were performed. Thus, the paper presents the results of a prospective exercise for the oil refining industry which has been carried out with the worldwide refining model OURSE according to the oil product demand projections of European Commission for Europe with the PRIMES model (European Commission, 2010) and the IFP projections for the rest of the World.JRC.J.1-Economics of Climate Change, Energy and Transpor

Optical ground station optimization for future optical geostationary satellite feeder uplinks

An optical link based on a multiplex of wavelengths at 1.55µm is foreseen to be a valuable alternative to the conventional radio-frequencies for the feeder link of the next-generation of high throughput geostationary satellite. Considering the limited power of lasers envisioned for feeder links, the beam divergence has to be dramatically reduced. Consequently, the beam pointing becomes a key issue. During its propagation between the ground station and a geostationary satellite, the optical beam is deflected (beam wandering), and possibly distorted (beam spreading), by atmospheric turbulence. It induces strong fluctuations of the detected telecom signal, thus increasing the bit error rate (BER). A steering mirror using a measurement from a beam coming from the satellite is used to pre-compensate the deflection. Because of the point-ahead angle between the downlink and the uplink, the turbulence effects experienced by both beams are slightly different, inducing an error in the correction. This error is characterized as a function of the turbulence characteristics as well as of the terminal characteristics, such as the servo-loop bandwidth or the beam diameter, and is included in the link budget. From this result, it is possible to predict intensity fluctuations detected by the satellite, both statistically (mean intensity, scintillation index, probability of fade, etc.) and temporally (power spectral densities, time series). The final objective is to optimize the different parameters of an optical ground station capable of mitigating the impact of atmospheric turbulence on the uplink in order to be compliant with the targeted capacity (1Terabit/s by 2025)

RZ-DPSK Optical Modulation For free Space Optical Communication Satellites

We demonstrate up to 4 dB improvement in optical receiver sensitivity using Return-to-Zero Differential Phase Shift Keying (RZ-DPSK) modulation compared with Non-Return-to-Zero On Off Keying (NRZ-OOK) in free space optical communication from satellite to ground at 40 Gbit/s data rate. This has been assessed using simulation software. An experiment is taking place to validate this result for 10 Gbit/s

Apprentissage de la pensée informatique : de la formation des enseignant·e·s à la formation de tou·te·s les citoyen·ne·s

National audienceIn recent years, in France, computer learning (under the term of code) has entered the school curriculum, in primary and high school. This learning is also aimed at developing computer thinking to enable students, girls and boys, to start master all aspects of the digital world (science, technology, industry, culture). However, neither teachers, nor parents are trained to teach or educate on these topics. Furthermore, if the educational system progresses progressively towards these objectives, in everyday life and in professional context there is also a need for lifelong training in computer thinking. Large-scale projects on coding initiation are now quite successful in supporting the training of professionals in education on these topics. However, they require an infrastructure of people and important resources to maintain their level of efficiency. In order to further develop the objectives of helping people to demystify IT thinking, we aim to question here the way by which it is possible to conceive a concrete and operational initiative that addresses this issue. A huge challenge: Let's share a proposal here and discuss it.En France au cours de ces dernières années, l’apprentissage de l’informatique (sous le terme d’«​ ​ apprentissage du code​ ​ ») est entré dans les programmes scolaires, en primaire et secondaire. Cet apprentissage vise notamment le développement de la pensée informatique (au sens défini par Wing) afin de permettre aux élèves, filles et garçons, d’acquérir les bases, une étape initiale vers la maîtrise du numérique, sous tous ses aspects (science, technologie, industrie et culture). Cependant, peu d’enseignant·e·s, ou de parents, ont été formé·e·s pour enseigner les sciences du numérique ou éduquer à leurs fondements et leurs usages. De plus, si le système éducatif avance progressivement au niveau de ces objectifs, dans la vie quotidienne et en contexte professionnel, il existe aussi un besoin de formation tout au long de la vie à la pensée informatique. Des projets d’envergure sur l’apprentissage du code sont aujourd’hui forts d’un véritable succès en matière de support à la formation des professionnel·le·s de l’éducation sur ces sujets. Cependant ces projets nécessitent une main d'oeuvre importante tant pour la création de ressources que pour leur actualisation, afin de rester en phase avec les besoins de formation dans un domaine en évolution constante. Dans le but de développer davantage les objectifs de démystification de la pensée informatique vers un large public de citoyens et de citoyennes, nous voulons questionner ici la manière dont il est possible de concevoir une initiative concrète et opérationnelle qui relève ce défi. Partageons ici une proposition et discutons-la. Ce qui est proposé porte un nom : une Université, Citoyenne en Sciences et Culture du Numérique (#UCscN) qui s’inscrit dans la tradition des universités populaires. Il s’agit donc très simplement d’étendre à toutes et tous cette éducation pour penser l’informatique en capitalisant sur l’expérience acquise de Class’Code en formant les professionnel·le·s de l’éducation

Apprentissage de la pensée informatique : de la formation des enseignant·e·s à la formation de tou·te·s les citoyen·ne·s

National audienceIn recent years, in France, computer learning (under the term of code) has entered the school curriculum, in primary and high school. This learning is also aimed at developing computer thinking to enable students, girls and boys, to start master all aspects of the digital world (science, technology, industry, culture). However, neither teachers, nor parents are trained to teach or educate on these topics. Furthermore, if the educational system progresses progressively towards these objectives, in everyday life and in professional context there is also a need for lifelong training in computer thinking. Large-scale projects on coding initiation are now quite successful in supporting the training of professionals in education on these topics. However, they require an infrastructure of people and important resources to maintain their level of efficiency. In order to further develop the objectives of helping people to demystify IT thinking, we aim to question here the way by which it is possible to conceive a concrete and operational initiative that addresses this issue. A huge challenge: Let's share a proposal here and discuss it.En France au cours de ces dernières années, l'apprentissage de l'informatique (sous le terme d'« apprentissage du code ») est entré dans les programmes scolaires, en primaire et secondaire. Cet apprentissage vise notamment le développement de la pensée informatique (au sens défini par Wing) afin de permettre aux élèves, filles et garçons, d'acquérir les bases, une étape initiale vers la maîtrise du numérique, sous tous ses aspects (science, technologie, industrie et culture). Cependant, peu d'enseignant·e·s, ou de parents, ont été formé·e·s pour enseigner les sciences du numérique ou éduquer à leurs fondements et leurs usages. De plus, si le système éducatif avance progressivement au niveau de ces objectifs, dans la vie quotidienne et en contexte professionnel, il existe aussi un besoin de formation tout au long de la vie à la pensée informatique. Des projets d'envergure sur l'apprentissage du code sont aujourd'hui forts d'un véritable succès en matière de support à la formation des professionnel·le·s de l'éducation sur ces sujets. Cependant ces projets nécessitent une main d'oeuvre importante tant pour la création de ressources que pour leur actualisation, afin de rester en phase avec les besoins de formation dans un domaine en évolution constante. Dans le but de développer davantage les objectifs de démystification de la pensée informatique vers un large public de citoyens et de citoyennes, nous voulons questionner ici la manière dont il est possible de concevoir une initiative concrète et opérationnelle qui relève ce défi. Partageons ici une proposition et discutons-la. Ce qui est proposé porte un nom : une Université, Citoyenne en Sciences et Culture du Numérique (#UCscN) qui s'inscrit dans la tradition des universités populaires. Il s'agit donc très simplement d'étendre à toutes et tous cette éducation pour penser l'informatique en capitalisant sur l'expérience acquise de Class'Code en formant les professionnel·le·s de l'éducation

Use of clustering techniques for automated lumping of components in compositional models

Compositional reservoir simulation run times scale with the square of the number of components used to characterize the fluid. Therefore, having usable and practical reservoir models requires that we minimize the number of components without sacrificing prediction accuracy. In this work we: 1. Validate a novel approach that automates the compositional lumping by using clustering techniques that allow the number of components to be controlled 2. Discuss its implementation into a simulator pre-processor to allows quick evaluation of the impact on production profiles and run-times of reducing the number of components in actual simulation runs 3. Explore alternative approaches to compressing the compositional data in the simulator cells to allow component convection to be carried out in compressed format using: (a) Singular Value Decomposition (SVD) (b) Non-negative matrix factorization (NNMF) (c) Auto-encoders (AE

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GLN-6557Besson, Lausanne et Genève, n° 112Copinger, n° 492Goff, Suppl. A-807aGW, n° 2111Hain, n° 1169IGI, n° 632ISTC, n° ia00807500Lökkös, BPU, n° 32Lökkös, Genève, n° 30Madsen, Copenhague, n° 241Parguez, Rhône-Alpes, n° 59Pellechet, Lyon, n° 24Pellechet-Polain, n° 822Sack, Freiburg i. B., n° 215Torchet, Loire, n° 55USTC, n° 45225