ASTER

L'ANSTJ se donne pour objectif de faire pratiquer les sciences et les techniques à un public de jeunes. Depuis vingt ans qu'elle existe, les activités qu'elle organise ont beaucoup évolué. La structure de projet demeure une constante, mais on est passé de projets de réalisation technique avec les clubs aérospatiaux du début à des projets de recherche collective dans des champs diversifiés, tels que l'astronomie, l'énergie solaire, l'informatique. Parallèlement un modèle pédagogique orienté vers la découverte de la démarche expérimentale a été progressivement formalisé. L'auteur s'appuie sur l'analyse des textes produits dans l'association ainsi que sur son expérience de participant puis d'animateur pour analyser cette évolution et les conditions qui l'ont amenée.

This work is aimed at estimating the sulfur dioxide emission of Mt. Etna volcano (Sicily, Italy) using the thermal infrared images remotely sensed by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). A new procedure (named FUN) is presented based on approximating functions which represent the atmospheric terms of the radiative transfer equation: transmittance, up-welling and down-welling radiances. The parameters of the approximating functions have been computed through the MODTRAN simulations performed using atmospheric monthly mean profiles measured at Trapani (1989Trapani ( -2003. Trapani (WMO station 16429) is located at the western tip of Sicily and is the closest station to Mt. Etna volcano. With these functions MODTRAN is no longer necessary to compute the SO 2 abundance in the plume emitted from Mt. Etna and seen by ASTER. Only an atmospheric radiosounding and a digital elevation model (DEM) registered to the ASTER image are required. This new procedure is compared with the known look-up tables (LUT) procedure proposed by other authors. An interesting aspect of the FUN procedure derives from its combined use with a split window (SW) algorithm. In this case only radiosounding is required to compute the SO 2 map. The FUN procedure presented in this paper is a rapid, simple and accurate means of generating SO 2 map estimates from the ASTER view of Mt. Etna.

This paper describes the problems involved with learning and understanding math for vision impaired students and developing a computer system approach for rendering mathematical formulae into audio form. Access to mathematics is an obstacle for blind students. The lack of easy access to mathematical resources is a barrier to higher education for many blind students and puts them at an unfair disadvantage in school, academia, and industry [1]. Results from the National Assessment of Educational Progress show that there is great disparity between the math skills of students with disabilities and students without disabilities [2]. A methodology for rendering technical documents, in particular, complex mathematical formula, in an audio descriptive form (Mathspeak) is presented in this paper.

GIS and remote-sensing provides better options for managing resources and enhancing the productivity. This study is carried out to access the optimum Aqua farming or Aquaculture sites in Pune area. Using the different essential parameters for selecting sites provides the optimum sites in the project area that will help Aqua farmers and results in overall progress in Business. The present study has predicted that about 0.25% (64.22453 ha) of the total land area of Pune city are optimum aqua sites with availability of market and better network connections. Pune has fresh water sources that leads to huge production of fishes and will also contribute profits for aqua farmers. The implementation of GIS technologies in finding suitable site for aquaculture will give a great result in the market productions and profits. Rivers channels and Road networks analysis is the two important factors for selecting the Aqua sites. The analysis is done using LISS-III satellite imagery and aster image. The methodology adopted is based on standard scientific processes. Weighted overlay technique is used in order to frame the exact model surface buildup criteria for the optimum sites throughout the project area.

Ce texte reprend une recherche conduite dans le cadre d'un appel à association de l'INRP, unité CRESAS, de 1996 à 1999.
L'équipe que nous avons constituée souhaitait développer l'étude des processus de construction des connaissances chez les élèves en centrant ses analyses sur le rôle des interactions langagières dans les apprentissages en biologie.
Nous avons essayé de montrer que l'hétérogénéité cognitive au sein d'une classe peut constituer une richesse pour permettre des progrès cognitifs significatifs pour l'ensemble des élèves. Nous avons recherché comment tenir compte de cette diversité, en s'appuyant sur elle, et en l'utilisant dans l'élaboration des séquences. Nous nous sommes centrées sur l'étude des interactions langagières entre élèves au sein de petits groupes hétérogènes en observant une classe du cycle 3 de l'école élémentaire. Nos travaux apportent des éclairages sur le rôle des négociations de sens dans les apprentissages scolaires.

Flood related scientific and community-based data are rarely systematically collected and analysed in the Philippines. Over the last decades the Pagsangaan River Basin, Leyte, has experienced several flood events. However, documentation describing flood characteristics such as extent, duration or height of these floods are close to non-existing. To address this issue, computerized flood modelling was used to reproduce past events where there was data available for at least partial calibration and validation. The model was also used to provide scenario-based predictions based on A1B climate change assumptions for the area. The most important input for flood modelling is a Digital Elevation Model (DEM) of the river basin. No accurate topographic maps or Light Detection And Ranging (LIDAR)-generated data are available for the Pagsangaan River. Therefore, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Map (GDEM), Version 1, was chosen...

Groundwater is considered the major portion of the world's freshwater resources. One of the main challenges facing the sustainable development of Egypt is the need for better management of its limited fresh water resources. Groundwater exists in the Nile Valley, Nile Delta, Western Desert Oases, and Sinai Peninsula. Hydrogeological mapping of groundwater resources is one of the main tools for the controlled development of groundwater resources. Remotely sensed surface indicators of groundwater provide useful data where practical classical alternatives are not available. Integrated remote sensing and GIS are widely used in groundwater mapping. Locating potential groundwater targets is becoming more convenient, cost effective than invasive methods and efficient with the advent of a number of satellite imagery. The nature of remote sensing-based groundwater exploration is to delineate all possible features connected with localization of groundwater. Data,

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a high spatial resolution, multispectral imager with alongtrack stereo capabilities scheduled for launch on the first NASA spacecraft of the Earth Observing System (EOS AM-1) in mid-199 . Data will be obtained in 14 spectral bands covering the visible through the < hermal infrared wavelength region. A number of standard data products will be available to requesters through an on-line archival and processing system. Particular, user-specified data acquisitions will be possible through a Data Acquisition Request system. res0000913 06-09-99 2 0 : 5 7 : 4 0 R.-W 1 4 -0 5 r e s 0 0 0 0 9 1 3 0 6 -0 9 -9 9 2 0 : 5 7 : 4 0 R e v 1 4 . 0 5 The Charlesworth Group, Huddersfield 01484 517077

Dans la perspective d'enrichir l'éducation scientifique d'une dimension citoyenne, et plus spécifi quement écocitoyenne, la prise en compte des questions socioécologiques requiert l'intégration dans les curriculums de sciences, d'objectifs relevant d'une éducation relative à l'environnement. Or, le contexte actuel de promotion du développement durable (DD) à l'échelle nationale et internationale fait appel au recadrage de l'éducation à l'environnement dans une perspective de DD. Le projet planétaire d'éducation pour le développement durable (ÉDD) propose d'axer désormais l'effort éducatif, non pas sur le rapport à l'environnement et la reconstruction du réseau des relations au milieu de vie, mais sur l'avènement d'un « développement » que l'on souhaite durable. Dans un tel contexte de mouvance curriculaire, de prescriptions ministérielles, de débats et de controverses, ce numéro d'Aster se penche sur les enjeux que soulèvent l'intégration de préoccupations environnementales et la visée du développement durable à l'enseignement des sciences. 1 Nous nous proposons d'utiliser dans le contexte français l'appellation « éducation à l'environnement » et l'acronyme ÉE, car c'est ainsi que s'y est contextualisée l'ÉRE. Néanmoins, quand nous ferons référence au contexte international, nous utiliserons l'appellation « éducation relative à l'environnement » et l'acronyme ÉRE, car c'est la proposition de l'UNESCO dans le programme international d'éducation relative à l'environnement. 2 Une circulaire datant de juillet 2004 précise les conditions de généralisation de l'ÉEDD dans l'enseignement scolaire.

Les échanges langagiers sont nécessairement inscrits dans un contexte déterminé. Ici nous abordons l'argumentation dans les débats en classe sur des questions socialement vives. Après avoir défini ce que nous entendons par « questions socialement vives » dont font partie les biotechnologies à vocation agricole, nous illustrons notre propos par l'analyse d'une étude de cas portant sur la comparaison de deux situations-débats sur une question socialement vive : une transgenèse animale. L'analyse se fait à des niveaux de plus en plus fins, de l'analyse macroscopique des débats dans leur entier à l'analyse de l'argumentation dans la langue à partir d'extraits, en passant par l'analyse microscopique d'épisodes argumentatifs. ASTERN" 37.2003. Interacttonslcmgagières l,INIU>-oeàacuond , ASTER-29med'lJbn-75230 Paris Cedex 05

Chikurachki volcano (Northern Kurile Islands Chain, Paramushir Island 50-20VN, 155-27VE; elevation 1816 m, stratovolcano) has been in a state of unrest for over twenty years. Its most recent eruption that began in April 2003 was preceded by an eruption between January and May 2002. Thermal infrared images from the Japanese -United States' Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER-5 TIR channels, 8 -12 Am, 90 m/pixel, Noise Equivalent Delta Temperature [NEDT]¨0.1 -0.3 K; onboard the U.S. National Aeronautics and Space Administration's Terra polar-orbiting spacecraft) of a snow-covered Chikurachki Volcano taken in January 2003 show muted evidence of thermal activity. ASTER thermal infrared (TIR) images from February 2003, however, indicate warmer areas within the summit crater. Average whole-pixel temperatures of adjacent summit slopes are in the range of 250 -252 K, while many summit-crater whole pixel temperatures are¨2 -6 K greater. A two component Planck solution for the warmer pixels yields a solution of 275 -277 K for 10 -15% of the Chikurachki summit crater and 285 -295 K for 25 -35% of a prominent ''hotspot'' on its flank. An interpretation of this enhanced preeruption heat flow is the presence of surface melt water. The detection in ASTER data of such subtle precursory heat-flow enhancement, even retrospectively, raises important issues for remote monitoring of ''dormant'' snow-capped volcanoes, especially those that threaten nearby populations, like Mt. Rainier. D

Dans le cadre d'une recherche de l'INRP, intitulée "Des images pour apprendre les sciences", nous nous sommes intéressées aux situations didactiques au cours desquelles des élèves sont placés face à des images et nous avons conduit des observations dans des classes de CM1 et CM2 (enfants de 9 à 11 ans). Nous utilisons ici les résultats obtenus dans une classe de CM1 lors de l'étude de la reproduction humaine. Partant du principe que tout apprentissage conceptuel doit se traduire par une évolution favorable des conceptions des élèves, nous avons mis en place un dispositif permettant de suivre pas à pas les progrès des élèves pour savoir si les tâches réalisées autour des images les aident à mieux comprendre les phénomènes étudiés. Nous nous sommes en particulier attachées aux tâches qui consistent à lire et à élaborer différents schémas et nous avons essayé d'évaluer leur efficacité. Les activités proposées aux élèves avaient également pour but de développer leur capacité à schématiser et nous avons essayé d'évaluer les progrès effectués dans ce domaine.

This paper proposes an integration of Spectral Mixture Analysis and Endmember Remote Sensing Indices to derive land surface temperature (LST), to identify urban heat islands (UHI) and to investigate their relationships to land use/land cover (LULC) and air-pollution in Tabriz city, Iran. LST values are assessed from ASTER remotely sensed thermal images to appraise the intensity of UHIs through a statistical approach. The results indicate that LST is highly influenced by LULC and that UHIs are closely linked to LST and LULC. As expected, LST is sensitive to vegetation and moisture and low temperatures are found in water bodies and vegetated areas. High temperatures are related to construction zones and industrial sites which are not necessarily located in the city centre. While the results demonstrate a high correlation between UHIs and air-pollution spatial analysis discloses a different pattern: when correlating identified UHI zones with air pollution the market area of Tabriz city reveals the highest measured PM values.

Résumé/Abstract L&#x27;Éducation à l&#x27;environnement (ÉE) est citée dans les textes officiels français depuis 1971. Ceux de 1993 demandaient un regard pluridisciplinaire soit dans le cadre de projets, soit au sein de chaque discipline. Parmi ces dernières, les sciences de ...

The Neoproterozoic Wadi Kid metamorphic belt in southeastern Sinai in Egypt represents a structurally and metamorphically complex assemblage of metasedimentary and metavolcanic rocks folded into a series of ENE-WSW-trending antiforms and synforms. Geological mapping in this region is challenging, primarily due to difficult access, complexity of structures, and lack of resolution and areal integrity of lithological differentiation using conventional mapping techniques. Spectral ratioing of selected bands of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data of the area, in synergy with geological field observation, proved effective in resolving geological mapping problems in the region. A new ASTER band-ratio image 4/7-4/6-4/10 is applied successfully for lithological mapping in the Wadi Kid area, showing improvement over previous techniques in detailing the main rock units. These are gneiss and migmatite, amphibolite, volcanogenic sediments with banded iron formation, meta-pelites, talc schist, meta-psammites, meta-acidic volcanics, meta-pyroclastics volcaniclastics, albitites and granitic rocks. Validating the use of the new ASTER band-ratio image relied on both calculating statistical optimum index factor (OIF) and matching interpreted lithological boundaries to field data and previously published geologic maps. The adopted ASTER band-ratio image demonstrates the benefit of using ASTER remote sensing data in lithological mapping of the Wadi Kid area and therefore for lithological mapping in the Arabian-Nubian shield and other arid areas.

تتناول الدراسة شدة الجزيرة الحرارية لمدينة المنصورة وتباينها الداخلي على المستوى المكاني والزمني، وعلاقة ذلك بالقصور الحراري وخصائصه. وقد اعتمدت الدراسة على الاستشعار من بعد بشكل رئيسي لمعالجة وتحليل المرئيات الفضائية بهدف استخلاص العمران الحضري آليا، والتعرف على أنماط الأسطح الأرضية بالمدينة وظهيرها، وحساب درجات الحرارة والألبيدو السطحي، واستخدام النماذج الرياضية المتقدمة لحساب القصور الحراري. وقد أظهرت الدراسة أن المواد والأسطح الحضرية في المنصورة تتسم بقصور حراري مرتفع عن الظهير الزراعي بنحو 7.3٪ في المتوسط بسبب السعة الحرارية العالية وقدرتها على توصيل الحرارة، وهو ما يساهم بشكل فعال في تحديد سرعة استجابة المدينة للتسخين خلال النهار بفعل الإشعاع الشمسي، كما ينظم عملية بث الإشعاع الأرضي على مدار اليوم. وقد تبين أيضا أن القصور الحراري يحدد ملامح عدة للجزيرة الحرارية ويفسر كثيرا من خصائصها، مثل تباين شدة الجزيرة الحرارية بين النهار والليل، وظاهرة الهبوط الحراري الصباحي Morning Heat Sink، والتباين الحراري داخل المدينة. لذا تُوصي الدراسة بإجراء المزيد من البحوث التفصيلية التي تتناول القصور الحراري كعامل رئيسي يساهم في فهم المناخ التفصيلي للمدن المصرية، كما تُوصي بأن يُؤخذ في الاعتبار عند وضع أي استراتيجيات أو إجراءات تنفيذية تستهدف تحسين البيئة الحضرية أو التغلب على المشكلات الناجمة عن جزيرتها الحرارية.

Les conceptions sur la formation des maîtres sont implicites, diverses, contradictoires ; elles oublient trop souvent que les maîtres enseignent des disciplines scolaires. Comment penser aujourd'hui la formation des enseignants à la prise en charge de leur discipline ? Cet article propose un modèle d'analyse qui s'appuie sur deux idées directrices : 11 l'idée de référence (les activités scolaires sont des images de pratiques extérieures à l'école et prises comme références), 2/ l'idée de professionnalité (les enseignants doivent acquérir une double technicité, dans les pratiques de référence d'une part, et dans le guidage des activités et des apprentissages scolaires d'autre part). L'article présente enfin quelques réflexions sur les formations actuelles, inspirées par le "modèle référence-prq)essionnalité"'. ASTER N° 19. 1994. La didactique des sciences en Europe. INRP, 29, rue d'Ulm, 75230 Paris Cedex 05

Minicurso ministrado durante o VI Workshop Internacional Sobre Planejamento e Desenvolvimento Sustentável de Bacias Hidrográficas, realizado entre os dias 11 e 15 de julho de 2017, na Universidade Federal de Uberlândia, MG. O minicurso tratou de dados e suas aplicações utilizando o QGIS como plataforma de trabalho. Os dados hidrológicos foram extraídos a partir da ferramenta TauDEM.

The NW–SE trending Central Iranian Volcanic Belt hosts many well-known porphyry copper deposits in Iran. It becomes an interesting area for remote sensing investigations to explore the new prospects of porphyry copper and vein type epithermal gold mineralization. Two copper mining districts in southeastern segment of the volcanic belt, including Meiduk and Sarcheshmeh have been selected in the present study. The performance of Principal Component Analysis, band ratio and Minimum Noise Fraction transformation has been evaluated for the visible and near infrared (VNIR) and, shortwave infrared (SWIR) subsystems of ASTER data. The image processing techniques indicated the distribution of iron oxides and vegetation in the VNIR subsystem. Hydrothermal alteration mineral zones associated with porphyry copper mineralization identified and discriminated based on distinctive shortwave infrared (SWIR) properties of the ASTER data in a regional scale. These techniques identified new prospects of porphyry copper mineralization in the study areas. The spatial distribution of hydrothermal alteration zones has been verified by in situ inspection, X-ray diffraction (XRD) analysis, and spectral reflectance measurements. Results indicated that the integration of the image processing techniques has a great ability to obtain significant and comprehensive information for the reconnaissance stages of porphyry copper exploration in a regional scale. The results of this research can assist exploration geologists to find new prospects of porphyry copper and gold deposits in the other virgin regions before costly detailed ground investigations. Consequently, the introduced image processing techniques can create an optimum idea about possible location of the new prospects.► In this study we use ASTER data for porphyry copper exploration. ► We identify vegetation, iron oxide, clay minerals using ASTER data in regional scale. ► Spectral mapping methods using ASTER SWIR data discriminate alteration minerals. ► The techniques identify new prospects of copper mineralization in the study areas.

This study investigates the application of spectral image processing methods to ASTER data for mapping hydrothermal alteration zones associated with porphyry copper mineralization and related host rock. The study area is located in the southeastern segment of the Urumieh-Dokhtar Volcanic Belt of Iran. This area has been selected because it is a potential zone for exploration of new porphyry copper deposits. Spectral transform approaches, namely principal component analysis, band ratio and minimum noise fraction were used for mapping hydrothermally altered rocks and lithological units at regional scale. Spectral mapping methods, including spectral angle mapper, linear spectral unmixing, matched filtering and mixture tuned matched filtering were applied to differentiate hydrothermal alteration zones associated with porphyry copper mineralization such as phyllic, argillic and propylitic mineral assemblages.

Geologists have used remote sensing data since the advent of the technology for regional mapping, structural interpretation and to aid in prospecting for ores and hydrocarbons. This paper provides a review of multispectral and hyperspectral remote sensing data, products and applications in geology. During the early days of Landsat Multispectral scanner and Thematic Mapper, geologists developed band ratio techniques and selective principal component analysis to produce iron oxide and hydroxyl images that could be related to hydrothermal alteration. The advent of the Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) with six channels in the shortwave infrared and five channels in the thermal region allowed to produce qualitative surface mineral maps of clay minerals (kaolinite, illite), sulfate minerals (alunite), carbonate minerals (calcite, dolomite), iron oxides (hematite, goethite), and silica (quartz) which allowed to map alteration facies (propylitic, argillic etc.). The step toward quantitative and validated (subpixel) surface mineralogic mapping was made with the advent of high spectral resolution hyperspectral remote sensing. This led to a wealth of techniques to match image pixel spectra to library and field spectra and to unravel mixed pixel spectra to pure endmember spectra to derive subpixel surface compositional information. These products have found their way to the mining industry and are to a lesser extent taken up by the oil and gas sector. The main threat for geologic remote sensing lies in the lack of (satellite) data continuity. There is however a unique opportunity to develop standardized protocols leading to validated and reproducible products from satellite remote sensing for the geology community. By focusing on geologic mapping products such as mineral and lithologic maps, geochemistry, P-T paths, fluid pathways etc. the geologic remote sensing community can bridge the gap with the geosciences community. Increasingly workflows should be multidisciplinary and remote sensing data should be integrated with field observations and subsurface geophysical data to monitor and understand geologic processes.

TETHYS is a relational GIS database that combines geophysical, remote sensing, geochemical, and geochronological data, developed as a flexible resource for studying magmatic and geodynamic responses to continental collisions. In this paper, we demonstrate utility of our database by integrating field, remote sensing, and structural data, for detailed mapping and tectonic emplacement of Muslim Bagh ophiolite of western Pakistan. This ophiolite forms the uppermost part of a nappe pile which accreted onto the Indian continental margin during the closure of the Neo-Tethys during a pre-terminal collision that predated the final closure of Tethys during the major collision between India and Eurasia. Utilizing the TETHYS, Landsat, ASTER imagery, and a digital elevation model developed from the ASTER data are used to characterize the lithology and structure of the area. Use of image processing techniques improved the geologic map of the area, for a better understanding of the tectonic emplacement of the Muslim Bagh ophiolite. For the first time we report that the dikes in the Muslim Bagh ophiolite are cutting the metamorphic sole. Our preliminary geochemical data for sheeted dike complex suggest chemical affinities with arc-related rocks. This observation suggests that dikes were intruded in an island arc environment soon after the ophiolite was formed.

Many ore deposits are first detected in the field by the recognition of hydrothermally altered host rocks, and are typically zonally distributed. Ore deposits are often produced by fluid flow processes that alter the mineralogy and chemistry of the country rock. One of the main reason for extention using a multi-spectral and hyperspectral sensor is due to detect the optical characteristics of the Earth's surface using several of spectral bands. All previous studies show that remote sensing has a important impress to detection alteration zones. The Advanced Spaceborne Thermal Emission and Reflection Radimeter (ASTER) sensor measures reflected radiation in VNIR, SWIR and TIR electromagnetic energies. It is cheap and easily available. The alteration minerals in Siyahrud area have been successfully investigated in the field and have been successfully detected by processing of Aster data. The finding shows hydrothermal alteration, which can be a model in indicating the productive units in this region. This Alteration mapping have been used by principal component analysis method , band ratio and False Color Composit method. this study and field investigation shows the hydrothermal alteration zone related to: iron oxide-bearing & hydroxidebearing minerals and mineral endmembers related to epithermal gold include phyllosilicates minerals ( Kaolinite,Illite, Alunite minerals). Results indicates ASTER , s capability to provide information on alteration minerals which are importance for mineral exploration activatites.

This research focuses on the application of HyMap airborne hyperspectral data and ASTER satellite multispectral data to mineral exploration and lithologic mapping in the Arctic regions of central East Greenland. The study area is the Kap Simpson complex in central East Greenland. The Kap Simpson complex is one of the largest exposed Palaeogene felsic complexes of East Greenland. It has been the target of several mineral exploration projects. The analysis of the HyMap data produced a detailed picture of the spatial distribution of the alteration minerals in the Kap Simpson complex, unavailable from field-based studies in the area. The analysis of the ASTER data produced mineral maps which due to the moderate spatial and spectral resolution of the ASTER imagery can be useful for reconnaissance level mineral exploration. Colour composites of the mean normalized ASTER thermal bands display lithological information and detected a large felsic igneous intrusion that has not been shown on the recently compiled geological maps of the area. The results of this research have considerable potential to evaluate the use of hyperspectral and multispectral remote sensing for geological purposes in the Arctic regions of central East Greenland.

Accurate delineation of watershed and drainage networks is crucial for hydrological and geomorphological models, water resource management, change of floodplains, flood risk management, and surface water mapping. Since high-resolution digital elevation models (DEMs) are often not available, it is necessary to evaluate open source products. Various statistical measures were used to estimate the vertical accuracy of these freely available DEMs. Moreover, DEM products from Shuttle Radar Topography Mission (SRTM), Advanced Thermal Emission and Reflection Radiometer (ASTER), and Cartosat data were also compared. The study areas are located in the Vadodara district of Gujarat State of India. A comparison of SRTM-, ASTER-, and Cartosat-derived DEMs allowed a qualitative assessment of the vertical component of the error, whereas statistical measurements were used to estimate their vertical accuracy. In order to compare the frequency histograms of the elevation distributions in the DEMs in the study area, skewness and kurtosis were determined. Further, to obtain the degree of relationship between the DEMs, scatterplots, as well as correlation coefficients, were used. The results showed that all DEMs have imperfections in the delineation of a small river like Vishwamitri, and the comparison showed that SRTM 30 m and ASTER 30 m failed to delineate proper main drainage for the river. Cartosat 30 m DEM exhibited better results. The root mean square error (RMSE) was calculated as 7.21 m for ASTER and 3.24 m for SRTM. The correlation value of 0.94 indicates the existence of a strong positive linear correlation between SRTM and Cartosat. The study shows that for the study area ASTER elevation data were highly underestimated, whereas SRTM elevation data were slightly overestimated.

Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Phased Array L-band Synthetic Aperture Radar (PALSAR) images covering the Um Rus area in the Central Eastern Desert of Egypt were evaluated for mapping geologic structure, lithology, and gold-related alteration zones. The study area is covered by Pan-African basement rocks including gabbro and granodiorite intruded into a variable mixture of metavolcanics and metasediments. The first three principal component analyses (PCA1, PCA2, PCA3) in a Red-Green-Blue (RGB) of the visible through shortwave-infrared (VNIR + SWIR) ASTER bands enabled the discrimination between lithological units. The results show that ASTER band ratios ((2 + 4)/3, (5 + 7)/6, (7 + 9)/8) in RGB identifies the lithological units and discriminates the granodiorite very well from the adjacent rock units.

Satellite remote sensing methods are a powerful tool for detailed geologic analysis, especially in inaccessible regions of the earth's surface. Short-wave infrared (SWIR) bands are shown to provide spectral information bearing on the lithologic, structural, and geochemical character of rock bodies such as ophiolites, allowing for a more comprehensive assessment of the lithologies present, their stratigraphic relationships, and geochemical character. Most remote sensing data are widely available for little or no cost, along with user-friendly software for non-specialists. In this paper we review common remote sensing systems and methods that allow for the discrimination of solid rock (lithologic) components of ophiolite complexes and their structural relationships. Ophiolites are enigmatic rock bodies which associated with most, if not all, plate collision sutures. Ophiolites are ideal for remote sensing given their widely recognized diversity of lithologic types and structural relationships. Accordingly, as a basis for demonstrating the utility of remote sensing techniques, we briefly review typical ophiolites in the Tethyan tectonic belt. As a case study, we apply integrated remote sensing studies of a well-studied example, the Muslim Bagh ophiolite, located in Balochistan, western Pakistan. On this basis, we attempt to demonstrate how remote sensing data can validate and reconcile existing information obtained from field studies. The lithologic and geochemical diversity of Muslim Bagh are representative of Tethyan ophiolites. Despite it's remote location it has been extensively mapped and characterized by structural and geochemical studies, and is virtually free of vegetative cover. Moreover, integrating the remote sensing data with 'ground truth' information thus offers the potential of an improved template for interpreting remote sensing data sets of other ophiolites for which little or no field information is available.

Remote sensing data can be effectively used as a mean to build geological knowledge for poorly mapped terrains. Spectral remote sensing data from space- and air-borne sensors have been widely used to geological mapping, especially in areas of high outcrop density in arid regions. However, spectral remote sensing information by itself cannot be efficiently used for a comprehensive lithological classification of an area due to (1) diagnostic spectral response of a rock within an image pixel is conditioned by several factors including the atmospheric effects, spectral and spatial resolution of the image, sub-pixel level heterogeneity in chemical and mineralogical composition of the rock, presence of soil and vegetation cover; (2) only surface information and is therefore highly sensitive to the noise due to weathering, soil cover, and vegetation. Consequently, for efficient lithological classification, spectral remote sensing data needs to be supplemented with other remote sensing datasets that provide geomorphological and subsurface geological information, such as digital topographic model (DEM) and aeromagnetic data. Each of the datasets contain significant information about geology that, in conjunction, can potentially be used for automated lithological classification using supervised machine learning algorithms. In this study, support vector machine (SVM), which is a kernel-based supervised learning method, was applied to automated lithological classification of a study area in northwestern India using remote sensing data, namely, ASTER, DEM and aeromagnetic data. Several digital image processing techniques were used to produce derivative datasets that contained enhanced information relevant to lithological discrimination. A series of SVMs (trained using k-folder cross-validation with grid search) were tested using various combinations of input datasets selected from among 50 datasets including the original 14 ASTER bands and 36 derivative datasets (including 14 principal component bands, 14 independent component bands, 3 band ratios, 3 DEM derivatives: slope/curvatureroughness and 2 aeromagnetic derivatives: mean and variance of susceptibility) extracted from the ASTER, DEM and aeromagnetic data, in order to determine the optimal inputs that provide the highest classification accuracy. It was found that a combination of ASTER-derived independent components, principal components and band ratios, DEM-derived slope, curvature and roughness, and aeromagnetic-derived mean and variance of magnetic susceptibility provide the highest classification accuracy of 93.4% on independent test samples. A comparison of the classification results of the SVM with those of maximum likelihood (84.9%) and minimum distance (38.4%) classifiers clearly show that the SVM algorithm returns much higher classification accuracy. Therefore, the SVM method can be used to produce quick and reliable geological maps from scarce geological information, which is still the case with many under-developed frontier regions of the world.

The increased availability of remote sensing platforms with appropriate spatial and temporal resolution, global coverage and low financial costs allows for fast, semi-automated, and cost-effective estimates of changes in glacier parameters over large areas. Remote sensing approaches allow for regular monitoring of the properties of alpine glaciers such as ice extent, terminus position, volume and surface elevation, from which glacier mass balance can be inferred. Such methods are particularly useful in remote areas with limited field-based glaciological measurements. This paper reviews advances in the use of visible and infrared remote sensing combined with field methods for estimating glacier parameters, with emphasis on volume/area changes and glacier mass balance. The focus is on the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor and its applicability for monitoring Himalayan glaciers. The methods reviewed are: volumetric changes inferred from digital elevation models (DEMs), glacier delineation algorithms from multi-spectral analysis, changes in glacier area at decadal time scales, and AAR/ELA methods used to calculate yearly mass balances. The current limitations and on-going challenges in using remote sensing for mapping characteristics of mountain glaciers also discussed, specifically in the context of the Himalaya.

The mapping of hydrothermal alteration zones associated with mineralization is of paramount importance in searching for metal deposits. For this purpose, targeting alteration zones by analyzing airborne geophysical and satellite imagery provides accurate and reliable results. In the Kelâat M’Gouna inlier, located in the Saghro Massif of the Moroccan Anti Atlas, natural gamma-ray spectrometry and ASTER satellite data were used to map hydrothermal alteration zones. Natural gamma-ray spectrometry data were processed to produce maps of Potassium (K in %), Uranium (eU in ppm), Thorium (eTh in ppm) and ratios of K/eTh and K/eU. In addition, four-band ratios were computed, on ASTER data, to map the distribution of clay minerals, phyllitic minerals, propylitic minerals, and iron oxides. The combined results obtained from geophysical and satellite data were further exploited by fuzzy logic modelling using the Geographic Information System (GIS) to generate a mineral prospectivity map. Seven hydrothermal alteration zones likely to be favorable for mineralization have been identified. They show a spatial correlation with (i) known surface prospects and mineral occurrences, (ii) the granite-encasing contact zone, and (iii) the fault zones (Sidi Flah and Tagmout faults). This research therefore provides important information on the prospecting of mineral potential in the study area.

(élèves de 13 ans). Le cycle 3 de l'école primaire correspond aux trois dernières années de la scolarité primaire (élèves de 8 à 10 ans) : Cours élémentaire 2 (CE2), Cours Moyen 1 (CM1) et Cours Moyen 2 (CM2). (7) Goery Delacôte. Préface du Livre du professeur de 4 e de la collection Libre Parcours, Hachette. 1979. des programmes scolaires qui intègrent peu à peu l'astronomie Suivent ceux de l'école élémentaire, plus exactement du cours moyen en 1985 : Éléments d'astronomie : Le repérage dans l'espace. La mesure du temps La Terre et les astres : La rotation de la Terre sur elle-même et autour du Soleil. La succession des jours et des nuits, et des saisons. Les fuseaux horaires. Les phases de la Lune et son mouvement autour de la Terre ; les marées. Les planètes du Soleil. Au lycée à cette période, l'astronomie n'apparaît pas en tant que telle et on se limite à l'étude des planètes et des satellites en mécanique dans le cadre de l'étude des actions à distance. C'est seulement dans le cadre des 10 % d'activités libres, puis dans les projets d'action éducatives que l'astronomie est alors abordée. Dans la vingtaine d'années qui a suivi, les programmes d'astronomie de l'école élémentaire ont évolué : suppression de l'étude des marées en 1995, de l'explication des saisons en 2002, mais les nouveaux programmes dépassent maintenant les limites du système solaire en incluant une approche de l'Univers. Malgré ces modifications, la partie astronomie reste à ce jour clairement identifiée au cycle 3 sous la rubrique "Le ciel et la Terre". Au collège, c'est actuellement toujours en classe de Quatrième, dans la rubrique "lumière", qu'apparaissent quelques éléments d'astronomie (8): Structure du système solaire. Phases de la Lune. Éclipses. Vitesse de la lumière dans l'espace (ordres de grandeurs des distances dans l'univers ou des durées de propagation de la lumière qui lui correspondent). Au lycée enfin, les programmes applicables depuis la rentrée 2000 comportent une partie intitulée : "Exploration de l'espace", qui présente l'Univers qui nous entoure, de l'atome aux galaxies. "On apprend à s'y repérer par la mesure de distances, de l'échelle atomique à l'échelle astronomique, et à utiliser la lumière pour obtenir des renseignements sur les astres et la matière contenue dans l'espace" (9). Cette partie du programme est totalement nouvelle et soulève chez les enseignants un certain nombre de questions qui justifieraient une recherche didactique. (8) Programmes de la classe de Quatrième de 1992. (9) Programmes de la classe de Seconde de 2000. 1.1. L'étude des planètes dans les manuels Dans le manuel de sciences de la collection Gulliver, les auteurs (Astolfi et al., 1996), considèrent que ce thème tient une étoile, c'est hérissé de pointes

Traditionnellement l'enseignement scientifique se propose immédiatement d'introduire au savoir actuel La prise en compte des obstacles n'a de sens que si l'on se propose le passage de la pensée commune à la pensée scientifique de façon à caractériser une fonction polémique : le rejet des croyances. Mais on peut rester dans la représentation, ou bien nier l'idée d'obstacle de nombreuses façons. Pour travailler les obstacles il faut réunir un certain nombre de conditions qui rendent possible la mise au point de procédés. Pouvoir décomposer les avancées conceptuelles en étapes à franchir successivement. Analyser le polymorphisme des obstacles et leur réapparition dans diverses étapes de la démarche. Être attentif aux révolutions inaperçues par familiarité, ou par le caractère infinitésimal du changement apporté. Le cas Galilée permet d'analyser l'articulation entre les différentes étapes d'une démarche.