Science.gov

Sample records for zusammenhang zwischen dem

  1. Klimawandel auf dem Mars: Planetenforschung

    NASA Astrophysics Data System (ADS)

    Hauber, Ernst

    2003-11-01

    Es gibt mittlerweile eine bemerkenswerte Übereinstimmung zwischen geomorphologischen Beobachtungen und Vorhersagen über die Stabilität von Bodeneis sowie Klimamodellen des Mars. Letztere weisen darauf hin, dass es auf dem Mars in den letzten Millionen Jahren klimatische Umschwünge gegeben haben könnte. Dabei lagerten sich in höheren und mittleren Breiten mehrere Meter mächtige Schichten aus Eis und Staub ab, die sich später zwischen etwa 30° und 60° nördlicher und südlicher Breite teilweise wieder auflösten. Sollte diese Theorie zutreffen, könnten auch heute noch eishaltige Materialien unter einer isolierenden Schicht aus Staub bis in die Äquatorregionen zu finden sein.

  2. Zwischen Physik und Philosophie Ino Weber, Carl Friedrich von Weizscker, Ein Leben zwischen Physik und Philosophie

    E-print Network

    Falge, Eva

    Zwischen Physik und Philosophie Ino Weber, Carl Friedrich von Weizsäcker, Ein Leben zwischen Physik Philosoph? Die Einordnung Carl Friedrich von Weizsäckers in klassische Kategorien fällt schwer, denn sein zur Quantenphysik. Die noch junge Quantenmechanik der 1920er-Jahre warf ganz neue methodische und

  3. Model definition DEM summary

    E-print Network

    Kuhn, Matthew R.

    Model definition DEM summary Simple-shear Simulating undrained loading of sand with the discrete University of Portland EMI 2012 Conference South Bend, Indiana June 18­20, 2012 National Science Foundation_Undrained.pdf #12;Model definition DEM summary Simple-shear Nevada Sand Particles and contacts Model

  4. ASTER DEM performance

    USGS Publications Warehouse

    Fujisada, H.; Bailey, G.B.; Kelly, Glen G.; Hara, S.; Abrams, M.J.

    2005-01-01

    The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument onboard the National Aeronautics and Space Administration's Terra spacecraft has an along-track stereoscopic capability using its a near-infrared spectral band to acquire the stereo data. ASTER has two telescopes, one for nadir-viewing and another for backward-viewing, with a base-to-height ratio of 0.6. The spatial resolution is 15 m in the horizontal plane. Parameters such as the line-of-sight vectors and the pointing axis were adjusted during the initial operation period to generate Level-1 data products with a high-quality stereo system performance. The evaluation of the digital elevation model (DEM) data was carried out both by Japanese and U.S. science teams separately using different DEM generation software and reference databases. The vertical accuracy of the DEM data generated from the Level-1A data is 20 m with 95% confidence without ground control point (GCP) correction for individual scenes. Geolocation accuracy that is important for the DEM datasets is better than 50 m. This appears to be limited by the spacecraft position accuracy. In addition, a slight increase in accuracy is observed by using GCPs to generate the stereo data. ?? 2005 IEEE.

  5. The Oracle of DEM

    NASA Astrophysics Data System (ADS)

    Gayley, Kenneth

    2013-06-01

    The predictions of the famous Greek oracle of Delphi were just ambiguous enough to seem to convey information, yet the user was only seeing their own thoughts. Are there ways in which X-ray spectral analysis is like that oracle? It is shown using heuristic, generic response functions to mimic actual spectral inversion that the widely known ill conditioning, which makes formal inversion impossible in the presence of random noise, also makes a wide variety of different source distributions (DEMs) produce quite similar X-ray continua and resonance-line fluxes. Indeed, the sole robustly inferable attribute for a thermal, optically thin resonance-line spectrum with normal abundances in CIE is its average temperature. The shape of the DEM distribution, on the other hand, is not well constrained, and may actually depend more on the analysis method, no matter how sophisticated, than on the source plasma. The case is made that X-ray spectra can tell us average temperature, and metallicity, and absorbing column, but the main thing it cannot tell us is the main thing it is most often used to infer: the differential emission measure distribution.

  6. Hydrologic enforcement of lidar DEMs

    USGS Publications Warehouse

    Poppenga, Sandra K.; Worstell, Bruce B.; Danielson, Jeffrey J.; Brock, John C.; Evans, Gayla A.; Heidemann, H. Karl

    2014-01-01

    Hydrologic-enforcement (hydro-enforcement) of light detection and ranging (lidar)-derived digital elevation models (DEMs) modifies the elevations of artificial impediments (such as road fills or railroad grades) to simulate how man-made drainage structures such as culverts or bridges allow continuous downslope flow. Lidar-derived DEMs contain an extremely high level of topographic detail; thus, hydro-enforced lidar-derived DEMs are essential to the U.S. Geological Survey (USGS) for complex modeling of riverine flow. The USGS Coastal and Marine Geology Program (CMGP) is integrating hydro-enforced lidar-derived DEMs (land elevation) and lidar-derived bathymetry (water depth) to enhance storm surge modeling in vulnerable coastal zones.

  7. Discrete Element Method (DEM) Soil simulations --liquefaction

    E-print Network

    Kuhn, Matthew R.

    Discrete Element Method (DEM) Soil simulations -- liquefaction Granular materials: Are they simple simulations -- liquefaction Granular materials: Are they simple? Outline 1 Discrete Element Method (DEM) 2 Soil simulations -- liquefaction 3 Granular materials: Are they simple? Kuhn -- January 17, 2013 http

  8. Wiederbeginn nach dem Zweiten Weltkrieg

    NASA Astrophysics Data System (ADS)

    Strecker, Heinrich; Bassenge-Strecker, Rosemarie

    Dieses Kapitel schildert zunächst die Ausgangslage für die Statistik in Deutschland nach dem Zweiten Weltkrieg: Der statistische Dienst in den Besatzungszonen musste teilweise erst aufgebaut und der statistische Unterricht an den Hochschulen wieder in Gang gebracht werden. In dieser Lage ergriff der Präsident des Bayerischen Statistischen Landesamtes, Karl Wagner, tatkräftig unterstützt von Gerhard Fürst, dem späteren Präsidenten des Statistischen Bundesamtes, die Initiative zur Neugründung der Deutschen Statistischen Gesellschaft (DStatG). Die Gründungsversammlung 1948 im München wurde zu einem Meilenstein in der Geschichte der DStatG. Ziel war es, alle Statistiker zur Zusammenarbeit anzuregen, ihre Qualifikation an das internationale Niveau heranzuführen und die Anwendung neuerer statistischer Methoden in der Praxis zu fördern. Es folgten 24 Jahre fruchtbarer Arbeit unter Karl Wagner (1948-1960) und Gerhard Fürst (1960-1972). Der Beitrag skizziert die Statistischen Wochen, die Tätigkeit der Ausschüsse und die Veröffentlichungen in dieser Zeit.

  9. Das Informatik-Forum Stuttgart - mehr Dialog zwischen Theorie und Anwendung notwendig

    NASA Astrophysics Data System (ADS)

    Hieber, Ludwig

    Mit der Gründung des Informatik- Forum Stuttgart wird seit 1996 eine Plattform angeboten, die den Dialog zwischen der universitären Forschung, der Informatikausbildung und der IT-Wirtschaft in der Region Stuttgart intensivieren soll. In der Informatik hat sich eine Lücke zwischen Theorie und Anwendung entwickelt. Es ist nicht erkennbar, dass diese Lücke kleiner wird, eher das Gegenteil zeichnet sich ab. Verglichen mit anderen Branchen besteht die Gefahr, dass Anwender wesentlich später von Erkenntnissen aus der Forschung profitieren. Der entstandene Interaktionsstau zwischen Theorie und Anwendung der Informatik sollte abgebaut werden. An einigen Beispielen wird aufgezeigt, wo das besonders wichtig erscheint.

  10. Studien in dem Romanstil Otto Ludwigs

    E-print Network

    Trovillo, Bessie

    1910-01-01

    Literatur. Otto Ludwig, 1813-1865. Gesammelte Schriften. Adolphv v Stern, 1891, Bd. 1. "Biographie. "Zwischen Himmel und Erde." Bd. 2. "Die Heiterethei und ihr Widerspiel. Novellen." Bd. 3. "Dramen." Bd. 4. "Dramatische Fragmente." Bd. 5-6. "Studien... ScholarWorks | The University of Kansas Pre-1923 Dissertations and Theses Collection Otto Lugwigs Romanstill 1910 by Bessie Trovillo This work was digitized by the Scholarly Communications program staff in the KU Libraries’ Center for Digital Scholarship...

  11. An assessment of TanDEM-X GlobalDEM over rural and urban areas

    NASA Astrophysics Data System (ADS)

    Koudogbo, Fifamè N.; Duro, Javier; Huber, Martin; Rudari, Roberto; Eddy, Andrew; Lucas, Richard

    2014-10-01

    Digital Elevation Model (DEM) is a key input for the development of risk management systems. Main limitation of the current available DEM is the low level of resolution. DEMs such as STRM 90m or ASTER are globally available free of charge, but offer limited use, for example, to flood modelers in most geographic areas. TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement), the first bistatic SAR can fulfil this gap. The mission objective is the generation of a consistent global digital elevation model with an unprecedented accuracy according to the HRTI-3 (High Resolution Terrain Information) specifications. The mission opens a new era in risk assessment. In the framework of ALTAMIRA INFORMATION research activities, the DIAPASON (Differential Interferometric Automated Process Applied to Survey Of Nature) processing chain has been successfully adapted to TanDEM-X CoSSC (Coregistered Slant Range Single Look Complex) data processing. In this study the capability of CoSSC data for DEM generation is investigated. Within the on-going FP7 RASOR project (Rapid Analysis and Spatialisation and Of Risk), the generated DEM are compared with Intermediate DEM derived from the TanDEM-X first global coverage. The results are presented and discussed.

  12. Nonlocal similarity based DEM super resolution

    NASA Astrophysics Data System (ADS)

    Xu, Zekai; Wang, Xuewen; Chen, Zixuan; Xiong, Dongping; Ding, Mingyue; Hou, Wenguang

    2015-12-01

    This paper discusses a new topic, DEM super resolution, to improve the resolution of an original DEM based on its partial new measurements obtained with high resolution. A nonlocal algorithm is introduced to perform this task. The original DEM was first divided into overlapping patches, which were classified either as "test" or "learning" data depending on whether or not they are related to high resolution measurements. For each test patch, the similar patches in the learning dataset were identified via template matching. Finally, the high resolution DEM of the test patch was restored by the weighted sum of similar patches under the condition that the reconstruction weights were the same in different resolution cases. A key assumption of this strategy is that there are some repeated or similar modes in the original DEM, which is quite common. Experiments were done to demonstrate that we can restore a DEM by preserving the details without introducing artifacts. Statistic analysis was also conducted to show that this method can obtain higher accuracy than traditional interpolation methods.

  13. Topographic Avalanche Risk: DEM Sensitivity Analysis

    NASA Astrophysics Data System (ADS)

    Nazarkulova, Ainura; Strobl, Josef

    2015-04-01

    GIS-based models are frequently used to assess the risk and trigger probabilities of (snow) avalanche releases, based on parameters and geomorphometric derivatives like elevation, exposure, slope, proximity to ridges and local relief energy. Numerous models, and model-based specific applications and project results have been published based on a variety of approaches and parametrizations as well as calibrations. Digital Elevation Models (DEM) come with many different resolution (scale) and quality (accuracy) properties, some of these resulting from sensor characteristics and DEM generation algorithms, others from different DEM processing workflows and analysis strategies. This paper explores the impact of using different types and characteristics of DEMs for avalanche risk modeling approaches, and aims at establishing a framework for assessing the uncertainty of results. The research question is derived from simply demonstrating the differences in release risk areas and intensities by applying identical models to DEMs with different properties, and then extending this into a broader sensitivity analysis. For the quantification and calibration of uncertainty parameters different metrics are established, based on simple value ranges, probabilities, as well as fuzzy expressions and fractal metrics. As a specific approach the work on DEM resolution-dependent 'slope spectra' is being considered and linked with the specific application of geomorphometry-base risk assessment. For the purpose of this study focusing on DEM characteristics, factors like land cover, meteorological recordings and snowpack structure and transformation are kept constant, i.e. not considered explicitly. Key aims of the research presented here are the development of a multi-resolution and multi-scale framework supporting the consistent combination of large area basic risk assessment with local mitigation-oriented studies, and the transferability of the latter into areas without availability of higher resolution elevation modes. Worked examples are provided from different DEMs for Alpine as well as Central Asian study areas (including an avalanche cadaster of a mountain road in the Kyrgyz Republic), exploring the transfer of uncertainty parameters into regions where only lower resolution DEMs are available.

  14. Einfuhrung Softwareentwicklungspraktikum "Python mit dem Raspberry Pi"

    E-print Network

    Einf¨uhrung Softwareentwicklungspraktikum "Python mit dem Raspberry Pi" (WiSe 2015/2016) Clemens Hauptprojekt 4 Zeitplan 5 Raspberry Pi 6 Python 2 / 16 #12;Organisation 1/4 Lernziele Programmieren-Vortr¨age zu Hauptprojekt 03.02.2016: Hauptprojekt Abnahme 11 / 16 #12;Raspberry Pi Offene Plattform

  15. SHADED RELIEF, HILLSHADE, DIGITAL ELEVATION MODEL (DEM), ARIZONA

    EPA Science Inventory

    Shaded relief of the state of Arizona developed from 1-degree US Geological Survey (USGS) Digital Elevation Models (DEMs). DEM is a terminology adopted by the USGS to describe terrain elevation data sets in a digital raster form.

  16. SHADED RELIEF, HILLSHADE, DIGITAL ELEVATION MODEL (DEM), NEVADA

    EPA Science Inventory

    Shaded relief of the state of Nevada developed from 1-degree US Geological Survey (USGS) Digital Elevation Models (DEMs). DEM is a terminology adopted by the USGS to describe terrain elevation data sets in a digital raster form.

  17. Proteine am Anker: Interaktion zwischen Proteinen und Pharmaka jetzt detailliert analysierbar

    E-print Network

    Gerwert, Klaus

    Proteine am Anker: Interaktion zwischen Proteinen und Pharmaka jetzt detailliert analysierbar RUB-Biophysiker nutzen oberflächensensitive Spektroskopie 04.09.2012: RUB-Forscher vom Lehrstuhl für Biophysik haben eine Werkzeug in der Hand, um die Dynamik pharmakologisch interessanter Proteine im atomaren Detail zu

  18. Incorporating DEM Uncertainty in Coastal Inundation Mapping

    PubMed Central

    Leon, Javier X.; Heuvelink, Gerard B. M.; Phinn, Stuart R.

    2014-01-01

    Coastal managers require reliable spatial data on the extent and timing of potential coastal inundation, particularly in a changing climate. Most sea level rise (SLR) vulnerability assessments are undertaken using the easily implemented bathtub approach, where areas adjacent to the sea and below a given elevation are mapped using a deterministic line dividing potentially inundated from dry areas. This method only requires elevation data usually in the form of a digital elevation model (DEM). However, inherent errors in the DEM and spatial analysis of the bathtub model propagate into the inundation mapping. The aim of this study was to assess the impacts of spatially variable and spatially correlated elevation errors in high-spatial resolution DEMs for mapping coastal inundation. Elevation errors were best modelled using regression-kriging. This geostatistical model takes the spatial correlation in elevation errors into account, which has a significant impact on analyses that include spatial interactions, such as inundation modelling. The spatial variability of elevation errors was partially explained by land cover and terrain variables. Elevation errors were simulated using sequential Gaussian simulation, a Monte Carlo probabilistic approach. 1,000 error simulations were added to the original DEM and reclassified using a hydrologically correct bathtub method. The probability of inundation to a scenario combining a 1 in 100 year storm event over a 1 m SLR was calculated by counting the proportion of times from the 1,000 simulations that a location was inundated. This probabilistic approach can be used in a risk-aversive decision making process by planning for scenarios with different probabilities of occurrence. For example, results showed that when considering a 1% probability exceedance, the inundated area was approximately 11% larger than mapped using the deterministic bathtub approach. The probabilistic approach provides visually intuitive maps that convey uncertainties inherent to spatial data and analysis. PMID:25250763

  19. Einzelmolekül-Elektronik Transistoren aus dem Reagenzglas

    NASA Astrophysics Data System (ADS)

    Loos, Andreas

    2004-07-01

    Elektronische Bauteile aus einzelnen Molekülen herzustellen, ist ein Traum der Physiker (Physik in unserer Zeit 2003, 34 (6), 272). Vielleicht könnte der polyzyklische Kohlenwasserstoff Hexabenozocoronen (HBC) ein Stück weiter helfen. Ein Team um Frank Jäckel und Jürgen Rabe an der Berliner Humboldt-Universität hat zusammen mit Kollegen des Max-Planck-Instituts für Polymerforschung in Mainz aus dem bräunlichen Stoff Transistoren gemixt, die gerade mal ein Molekül groß sind [1].

  20. DEM time series of an agricultural watershed

    NASA Astrophysics Data System (ADS)

    Pineux, Nathalie; Lisein, Jonathan; Swerts, Gilles; Degré, Aurore

    2014-05-01

    In agricultural landscape soil surface evolves notably due to erosion and deposition phenomenon. Even if most of the field data come from plot scale studies, the watershed scale seems to be more appropriate to understand them. Currently, small unmanned aircraft systems and images treatments are improving. In this way, 3D models are built from multiple covering shots. When techniques for large areas would be to expensive for a watershed level study or techniques for small areas would be too time consumer, the unmanned aerial system seems to be a promising solution to quantify the erosion and deposition patterns. The increasing technical improvements in this growth field allow us to obtain a really good quality of data and a very high spatial resolution with a high Z accuracy. In the center of Belgium, we equipped an agricultural watershed of 124 ha. For three years (2011-2013), we have been monitoring weather (including rainfall erosivity using a spectropluviograph), discharge at three different locations, sediment in runoff water, and watershed microtopography through unmanned airborne imagery (Gatewing X100). We also collected all available historical data to try to capture the "long-term" changes in watershed morphology during the last decades: old topography maps, soil historical descriptions, etc. An erosion model (LANDSOIL) is also used to assess the evolution of the relief. Short-term evolution of the surface are now observed through flights done at 200m height. The pictures are taken with a side overlap equal to 80%. To precisely georeference the DEM produced, ground control points are placed on the study site and surveyed using a Leica GPS1200 (accuracy of 1cm for x and y coordinates and 1.5cm for the z coordinate). Flights are done each year in December to have an as bare as possible ground surface. Specific treatments are developed to counteract vegetation effect because it is know as key sources of error in the DEM produced by small unmanned aircraft systems. The poster will present the older and more recent changes of relief in this intensely exploited watershed and notably show how unmanned airborne imagery might be of help in DEM dynamic modelling to support soil conservation research.

  1. Zusatz- und Weiterqualifikation nach dem Studium

    NASA Astrophysics Data System (ADS)

    Domnick, Ivonne

    Ist der Bachelor geschafft, stellt sich die Frage nach einer Weiterqualifizierung. Neben einem Einstieg ins Berufsleben kann auch ein Masterstudium eventuell weitere entscheidende Bonuspunkte für den Lebenslauf bringen. Mit Zusatzqualifikationen aus fachfremden Bereichen wie Betriebswirtschaft oder Marketing ist es für Naturwissenschaftler leichter, den Einstieg ins Berufsleben zu schaffen. Viele Arbeitgeber sehen gerade bei Naturwissenschaftlern eine Promotion gerne. Hier sollte genau abgewogen werden, ob sie innerhalb einer bestimmten Zeitspanne zu schaffen ist. Auch nach einem Einstieg in den Job lässt sich der Doktortitel unter Umständen noch nachholen. Ebenso ist eine Weiterbildung neben dem Beruf in Teilzeit oder in einem Fernkurs möglich. Zusätzlich gibt es viele mehrwöchige oder mehrmonatige Kurse privater Anbieter, in denen man BWL-Grundkenntnisse erwerben kann.

  2. The TanDEM-X DEM — Status of the New Dataset for Studying Topography of the Global Impact Crater Record

    NASA Astrophysics Data System (ADS)

    Gottwald, M.; Fritz, T.; Breit, H.; Schaettler, B.; Harris, A.

    2015-07-01

    In the TanDEM-X mission two X-band radar satellites were operated as a single-pass SAR interferometer. From the acquired data a new digital elevation model is being generated. We report on the capabilities of this DEM for impact crater studies.

  3. N-to-One-Provisionierung zwischen internen Satellitenverzeichnissen des IntegraTUM-Metadirectory

    NASA Astrophysics Data System (ADS)

    Boursas, Latifa

    Dieser Beitrag beschreibt und analysiert die Synchronisationslösungen zur Verwaltung von Benutzerdaten, die Konnektoren aus verschiedenen Quellsystemen und zwischen Verzeichnisdiensten übertragen müssen. Der Schwerpunkt dieser Analyse liegt dabei auf den Transformationen, die zwei Datenmodelle mit unterschiedlichen Strukturen des Directory Information Tree (DIT) innerhalb des IntegraTUM-Metadirectory miteinander abgleichen. Besonders herausfordernd ist, diesen Abgleich mittels des Novell DirXML-Treibers zu realisieren, weil das DirXML-Datenmodell für die Synchronisation der LDAP-Objekte auf eins zu eins Synchronisation ausgelegt ist. In diesem Beitrag wird unsere Lösung für die Synchronisation mehreren LDAP-Objekte auf ein einziges Objekt detailliert und ihre Integrierbarkeit in anderen Hochschulen vorgestellt.

  4. EMDataBank unified data resource for 3DEM

    PubMed Central

    Lawson, Catherine L.; Patwardhan, Ardan; Baker, Matthew L.; Hryc, Corey; Garcia, Eduardo Sanz; Hudson, Brian P.; Lagerstedt, Ingvar; Ludtke, Steven J.; Pintilie, Grigore; Sala, Raul; Westbrook, John D.; Berman, Helen M.; Kleywegt, Gerard J.; Chiu, Wah

    2016-01-01

    Three-dimensional Electron Microscopy (3DEM) has become a key experimental method in structural biology for a broad spectrum of biological specimens from molecules to cells. The EMDataBank project provides a unified portal for deposition, retrieval and analysis of 3DEM density maps, atomic models and associated metadata (emdatabank.org). We provide here an overview of the rapidly growing 3DEM structural data archives, which include maps in EM Data Bank and map-derived models in the Protein Data Bank. In addition, we describe progress and approaches toward development of validation protocols and methods, working with the scientific community, in order to create a validation pipeline for 3DEM data. PMID:26578576

  5. Using DEM-CFD method at colloidal scale 

    E-print Network

    Chaumeil, Florian

    2013-11-28

    The aim of this work is to look into the applicability of Discrete Element Modelling (DEM) coupled to Computational Fluid Dynamics (CFD) to simulate micro-scale colloidal particles immersed in fluid. Numerical methods ...

  6. Tanzendes Tier oder exzentrische Positionalität - Philosophische Anthropologie zwischen Darwinismus und Kulturalismus

    NASA Astrophysics Data System (ADS)

    Fischer, Joachim

    Zunächst kurz vorweg zu den Formeln im Titel: "exzentrische Positionalität“ ist der Kategorienvorschlag der Philosophischen Anthropologie (genauer: von Helmuth Plessner) für den Menschen, für seine "Sonderstellung“ unter den Lebewesen - ich werde diesen Begriff erläutern. So viel kann man sagen: Der Terminus ist nicht schwieriger als "Transzendentalität“ oder das "Apriori“ oder "Autopoiesis“, also Begriffe, mit deren Orientierungswert in der intellektuellen Öffentlichkeit bereits gespielt wird, bietet aber möglicherweise mehr Erschließungskraft als die Kunstbegriffe z. B. von Kant, Maturana oder Luhmann. Und "tanzendes Tier“ ist ein glücklicher Anschauungsbegriff, eine Art Übersetzung für "exzentrische Positionalität“ - also ein "verrücktes“ Lebewesen, eine Verrückung im evolutionären Leben, die dieses Lebewesen von Natur aus zu einer bestimmten Art von Lebensführung, nämlich Kultur nötigt. Die Absicht des Beitrages ist es, die Philosophische Anthropologie als eine spezifische Theorietechnik zu präsentieren, um einen adäquaten Begriff des Menschen zu erreichen, und zwar eine Theoriestrategie angesichts des cartesianischen Dualismus - also des Dualismus zwischen Naturalismus und Kulturalismus.

  7. Shading-based DEM refinement under a comprehensive imaging model

    NASA Astrophysics Data System (ADS)

    Peng, Jianwei; Zhang, Yi; Shan, Jie

    2015-12-01

    This paper introduces an approach to refine coarse digital elevation models (DEMs) based on the shape-from-shading (SfS) technique using a single image. Different from previous studies, this approach is designed for heterogeneous terrain and derived from a comprehensive (extended) imaging model accounting for the combined effect of atmosphere, reflectance, and shading. To solve this intrinsic ill-posed problem, the least squares method and a subsequent optimization procedure are applied in this approach to estimate the shading component, from which the terrain gradient is recovered with a modified optimization method. Integrating the resultant gradients then yields a refined DEM at the same resolution as the input image. The proposed SfS method is evaluated using 30 m Landsat-8 OLI multispectral images and 30 m SRTM DEMs. As demonstrated in this paper, the proposed approach is able to reproduce terrain structures with a higher fidelity; and at medium to large up-scale ratios, can achieve elevation accuracy 20-30% better than the conventional interpolation methods. Further, this property is shown to be stable and independent of topographic complexity. With the ever-increasing public availability of satellite images and DEMs, the developed technique is meaningful for global or local DEM product refinement.

  8. Evaluating the Accuracy of dem Generation Algorithms from Uav Imagery

    NASA Astrophysics Data System (ADS)

    Ruiz, J. J.; Diaz-Mas, L.; Perez, F.; Viguria, A.

    2013-08-01

    In this work we evaluated how the use of different positioning systems affects the accuracy of Digital Elevation Models (DEMs) generated from aerial imagery obtained with Unmanned Aerial Vehicles (UAVs). In this domain, state-of-the-art DEM generation algorithms suffer from typical errors obtained by GPS/INS devices in the position measurements associated with each picture obtained. The deviations from these measurements to real world positions are about meters. The experiments have been carried out using a small quadrotor in the indoor testbed at the Center for Advanced Aerospace Technologies (CATEC). This testbed houses a system that is able to track small markers mounted on the UAV and along the scenario with millimeter precision. This provides very precise position measurements, to which we can add random noise to simulate errors in different GPS receivers. The results showed that final DEM accuracy clearly depends on the positioning information.

  9. Extract relevant features from DEM for groundwater potential mapping

    NASA Astrophysics Data System (ADS)

    Liu, T.; Yan, H.; Zhai, L.

    2015-06-01

    Multi-criteria evaluation (MCE) method has been applied much in groundwater potential mapping researches. But when to data scarce areas, it will encounter lots of problems due to limited data. Digital Elevation Model (DEM) is the digital representations of the topography, and has many applications in various fields. Former researches had been approved that much information concerned to groundwater potential mapping (such as geological features, terrain features, hydrology features, etc.) can be extracted from DEM data. This made using DEM data for groundwater potential mapping is feasible. In this research, one of the most widely used and also easy to access data in GIS, DEM data was used to extract information for groundwater potential mapping in batter river basin in Alberta, Canada. First five determining factors for potential ground water mapping were put forward based on previous studies (lineaments and lineament density, drainage networks and its density, topographic wetness index (TWI), relief and convergence Index (CI)). Extraction methods of the five determining factors from DEM were put forward and thematic maps were produced accordingly. Cumulative effects matrix was used for weight assignment, a multi-criteria evaluation process was carried out by ArcGIS software to delineate the potential groundwater map. The final groundwater potential map was divided into five categories, viz., non-potential, poor, moderate, good, and excellent zones. Eventually, the success rate curve was drawn and the area under curve (AUC) was figured out for validation. Validation result showed that the success rate of the model was 79% and approved the method's feasibility. The method afforded a new way for researches on groundwater management in areas suffers from data scarcity, and also broaden the application area of DEM data.

  10. Discrete Element Modeling (DEM) of Triboelectrically Charged Particles: Revised Experiments

    NASA Technical Reports Server (NTRS)

    Hogue, Michael D.; Calle, Carlos I.; Curry, D. R.; Weitzman, P. S.

    2008-01-01

    In a previous work, the addition of basic screened Coulombic electrostatic forces to an existing commercial discrete element modeling (DEM) software was reported. Triboelectric experiments were performed to charge glass spheres rolling on inclined planes of various materials. Charge generation constants and the Q/m ratios for the test materials were calculated from the experimental data and compared to the simulation output of the DEM software. In this paper, we will discuss new values of the charge generation constants calculated from improved experimental procedures and data. Also, planned work to include dielectrophoretic, Van der Waals forces, and advanced mechanical forces into the software will be discussed.

  11. Precise baseline determination for the TanDEM-X mission

    NASA Astrophysics Data System (ADS)

    Koenig, Rolf; Moon, Yongjin; Neumayer, Hans; Wermuth, Martin; Montenbruck, Oliver; Jäggi, Adrian

    The TanDEM-X mission will strive for generating a global precise Digital Elevation Model (DEM) by way of bi-static SAR in a close formation of the TerraSAR-X satellite, already launched on June 15, 2007, and the TanDEM-X satellite to be launched in May 2010. Both satellites carry the Tracking, Occultation and Ranging (TOR) payload supplied by the GFZ German Research Centre for Geosciences. The TOR consists of a high-precision dual-frequency GPS receiver, called Integrated GPS Occultation Receiver (IGOR), and a Laser retro-reflector (LRR) for precise orbit determination (POD) and atmospheric sounding. The IGOR is of vital importance for the TanDEM-X mission objectives as the millimeter level determination of the baseline or distance between the two spacecrafts is needed to derive meter level accurate DEMs. Within the TanDEM-X ground segment GFZ is responsible for the operational provision of precise baselines. For this GFZ uses two software chains, first its Earth Parameter and Orbit System (EPOS) software and second the BERNESE software, for backup purposes and quality control. In a concerted effort also the German Aerospace Center (DLR) generates precise baselines independently with a dedicated Kalman filter approach realized in its FRNS software. By the example of GRACE the generation of baselines with millimeter accuracy from on-board GPS data can be validated directly by way of comparing them to the intersatellite K-band range measurements. The K-band ranges are accurate down to the micrometer-level and therefore may be considered as truth. Both TanDEM-X baseline providers are able to generate GRACE baselines with sub-millimeter accuracy. By merging the independent baselines by GFZ and DLR, the accuracy can even be increased. The K-band validation however covers solely the along-track component as the K-band data measure just the distance between the two GRACE satellites. In addition they inhibit an un-known bias which must be modelled in the comparison, so the differences between the computed baselines and the K-band ranges vary around a mean. In the end a systematic deviation or bias cannot be detected this way. A 3-D assessment of the baseline accuracies including biases can be gained by comparison of independently derived baselines as here from GFZ and DLR. Indeed it turns out that the different baselines show systematic differences of a few millimeters. From this it can be concluded that for the TanDEM-X mission an unknown bias in the baselines is possible which in turn would hurt the anticipated DEM accuracy limit. In order to control a possible baseline bias, a calibration chain via SAR calibration data takes has been invented in the TanDEM-X ground segment. This chain delivers corrections to the baseline bias so that unbiased baselines with sub-millimeter accuracies can be provided to secure the DEM accuracy requirement.

  12. Supraleitung und Interkontinentalraketen „On-line computing“ zwischen Militär, Industrie und Wissenschaft

    NASA Astrophysics Data System (ADS)

    Knolle, Johannes; Joas, Christian

    Der zweite Weltkrieg und der Kalte Krieg veränderten nicht nur das Verhältnis zwischen Militär, Industrie und Wissenschaft, sondern auch die wissenschaftliche Praxis von Physikern und anderen Wissenschaftlern. In den 1950er Jahren stellte die Entwicklung von Interkontinentalraketen die Auftragnehmer des Militärs in der Industrie vor komplexe Fragestellungen, zu deren Lösung sie auf die Expertise von Wissenschaftlern angewiesen waren. Industrieunternehmen gründeten eigene Forschungseinheiten zur Lösung technischer und wissenschaftlicher Probleme.

  13. Entwicklungsperspektiven von Social Software und dem Web 2.0

    NASA Astrophysics Data System (ADS)

    Raabe, Alexander

    Der Artikel beschäftigt sich zunächst mit dem derzeitigen und zukünftigen Einsatz von Social Software in Unternehmen. Nach dem großen Erfolg von Social Software im Web beginnen viele Unternehmen eigene Social Software-Initiativen zu entwickeln. Der Artikel zeigt die derzeit wahrgenommenen Einsatzmöglichkeiten von Social Software im Unternehmen auf, erörtert Erfolgsfaktoren für die Einführung und präsentiert mögliche Wege für die Zukunft. Nach der Diskussion des Spezialfalles Social Software in Unternehmen werden anschließend die globalen Trends und Zukunftsperspektiven des Web 2.0 in ihren technischen, wirtschaftlichen und sozialen Dimensionen dargestellt. Wie aus den besprochenen Haupttrends hervorgeht, wird die Masse an digital im Web verfügbaren Informationen stetig weiterwachsen. So stellt sich die Frage, wie es in Zukunft möglich sein wird, die Qualität der Informationssuche und der Wissensgenerierung zu verbessern. Mit dem Einsatz von semantischen Technologien im Web wird hier eine revolutionäre Möglichkeit geboten, Informationen zu filtern und intelligente, gewissermaßen verstehende" Anwendungen zu entwerfen. Auf dem Weg zu einem intelligenten Web werden sich das Semantic Web und Social Software annähern: Anwendungen wie Semantic Wikis, Semantic Weblogs, lightweight Semantic Web-Sprachen wie Microformats oder auch kommerzielle Angebote wie Freebase von Metaweb werden die ersten Vorzeichen einer dritten Generation des Webs sein.

  14. DEMS - a second generation diabetes electronic management system.

    PubMed

    Gorman, C A; Zimmerman, B R; Smith, S A; Dinneen, S F; Knudsen, J B; Holm, D; Jorgensen, B; Bjornsen, S; Planet, K; Hanson, P; Rizza, R A

    2000-06-01

    Diabetes electronic management system (DEMS) is a component-based client/server application, written in Visual C++ and Visual Basic, with the database server running Sybase System 11. DEMS is built entirely with a combination of dynamic link libraries (DLLs) and ActiveX components - the only exception is the DEMS.exe. DEMS is a chronic disease management system for patients with diabetes. It is used at the point of care by all members of the diabetes team including physicians, nurses, dieticians, clinical assistants and educators. The system is designed for maximum clinical efficiency and facilitates appropriately supervised delegation of care. Dispersed clinical sites may be supervised from a central location. The system is designed for ease of navigation; immediate provision of many types of automatically generated reports; quality audits; aids to compliance with good care guidelines; and alerts, advisories, prompts, and warnings that guide the care provider. The system now contains data on over 34000 patients and is in daily use at multiple sites. PMID:10764939

  15. Spielerisches Erlernen der Programmierung mit dem Java-Hamster-Modell

    E-print Network

    Appelrath, Hans-Jürgen

    Spielerisches Erlernen der Programmierung mit dem Java- Hamster-Modell Dietrich Boles Department Oldenburg boles@informatik.uni-oldenburg.de Abstract: Das Java-Hamster-Modell ist ein spezielles Programmierkonzepte und den Programmentwurf kennen, indem sie so genannte Hamster-Programme entwickeln, mit denen sie

  16. Spatial Characterization of Landscapes through Multifractal Analysis of DEM

    PubMed Central

    Aguado, P. L.; Del Monte, J. P.; Moratiel, R.; Tarquis, A. M.

    2014-01-01

    Landscape evolution is driven by abiotic, biotic, and anthropic factors. The interactions among these factors and their influence at different scales create a complex dynamic. Landscapes have been shown to exhibit numerous scaling laws, from Horton's laws to more sophisticated scaling of heights in topography and river network topology. This scaling and multiscaling analysis has the potential to characterise the landscape in terms of the statistical signature of the measure selected. The study zone is a matrix obtained from a digital elevation model (DEM) (map 10 × 10?m, and height 1?m) that corresponds to homogeneous region with respect to soil characteristics and climatology known as “Monte El Pardo” although the water level of a reservoir and the topography play a main role on its organization and evolution. We have investigated whether the multifractal analysis of a DEM shows common features that can be used to reveal the underlying patterns and information associated with the landscape of the DEM mapping and studied the influence of the water level of the reservoir on the applied analysis. The results show that the use of the multifractal approach with mean absolute gradient data is a useful tool for analysing the topography represented by the DEM. PMID:25177728

  17. TSUNAMI INUNDATION MAPPING FOR OCEAN CITY, MD NGDC DEM

    E-print Network

    Kirby, James T.

    TSUNAMI INUNDATION MAPPING FOR OCEAN CITY, MD NGDC DEM BY BABAK TEHRANIRAD, SAEIDEH BANIHASHEMI BY THE NATIONAL TSUNAMI HAZARD MITIGATION PROGRAM NATIONAL WEATHER SERVICE GRANT NA10NWS4670010 CENTER FOR APPLIED COASTAL RESEARCH Ocean Engineering Laboratory University of Delaware Newark, Delaware 19716 #12;Tsunami

  18. EXOTICPEST ALERT Horse chestnut leaf miner, Cameraria ohridella Desch. & Dem.

    E-print Network

    EXOTICPEST ALERT Horse chestnut leaf miner, Cameraria ohridella Desch. & Dem. (Lepidoptera: Gracillariidae) EXOTIC The first sighting in the UK of the leaf mining moth, Cameraria ohridella, was on chestnut in the premature defoliation of many horse chestnut trees. Horse chestnuts are widely used in prominent amenity

  19. Incorporating Atomic Data Errors in Stellar DEM Reconstruction

    E-print Network

    Wolfe, Patrick J.

    as a redistribution matrix to go from temperature space to wavelength space. The standard instrumental effective area Matrix, Atomic Data Error, Capella INTRODUCTION The differential emission measures (DEMs Nt matrix C represents the continuum emissivity matrix, the I Nt matrix k¨L k¨PC represents

  20. The TanDEM-X Digital Elevation Model and Terrestrial Impact Craters

    NASA Astrophysics Data System (ADS)

    Gottwald, Manfred; Harris, Alan; Fritz, Thomas; Breit, Helko; Schaettler, Birgit

    The Digital Elevation Model (DEM) derived in the TanDEM-X mission is generated from data of the German X-band TerraSAR-X and TanDEM-X satellites, launched in June 2007 and June 2010, respectively. The complete final TanDEM-X DEM will be available by 2015. It achieves global coverage together with an accuracy in the sub-10 m range and a spatial resolution of 12 m at the equator. Thus it exceeds the quality of current elevation models generated from space-borne remote sensing data, e.g., SRTM X-band (15m/30m with limited coverage) considerably. The TanDEM-X DEM supports studies of terrestrial impact craters by revealing the morphology and topography of simple and complex structures, together with the surrounding terrain, in great detail - even for craters in very remote areas. In a first approach we apply the TanDEM-X digital elevation data to the impact crater record of the exposed entries in the Earth Impact Database (EID) of the Planetary and Space Science Center at the University of New Brunswick, Canada. This allows evaluation of how structures of confirmed origin are reflected in the TanDEM-X DEM data. Our early assessment analyses - using intermediate DEM processing products - suggest that of the about 120 EID entries of the exposed type 80%-90% can be identified in the DEM data. As the final elevation data successively will emerge during processing, we will generate for all known impact structures with visible surface features a homogeneous set of information extracted from the TanDEM-X DEM including, e.g., high precision maps, elevation profiles, etc. This catalogue can be used for further detailed studies or the development of search algorithms for potential impact features in selected areas. This presentation describes the current status of our research and illustrates several TanDEM-X DEM maps of known terrestrial impact craters.

  1. Comparison of the extracted DEMs in Heihe River upper and middle reaches

    NASA Astrophysics Data System (ADS)

    Chao, Zhenhua; Nan, Zhuotong; Li, Xin; Mao, Zhihua

    2006-12-01

    The Digital Elevation Model (DEM) are terrain elevations at regularly spaced horizontal intervals, i.e., an a grid of regularly spaced elevations. With the development of computing technology, the methods of data acquisition, data storage and data processing speed for DEMs get along well. Heihe river lies in the northwest of China and is a continental river. It roots from snow-ice and disappears in deserts. The drainage area is about 140,000 square kilometers and the river is the main water source for the living. The upper reaches are mountainous and the runoff is very important. The middle reaches are oasis. At present, many hydrological and ecological models are introduced. The catchment basin and stream network data acquired from DEMs are main input data for many surface hydrological models. So the quality and resolution of DEMs are significant. Software ENVI Version 4.2 furnishes with the DEMs Extraction Module. The paper compared several methods for extracting DEMs of the upper reaches. We extracted the elevation data from the ASTER---stereo images with the module and created the DEM. Secondly; we collected the DEM based on the contour map of Heihe river. The comparison of the DEMs quality was carried out between the DEM from the contour map, the DEM extracted by ENVI Version 4.2. To a certain extent, the DEM from Aster imagery can reflect the terrain and be used in hydrological models.

  2. Constructing DEM from characteristic terrain information using HASM method

    NASA Astrophysics Data System (ADS)

    Song, Dunjiang; Yue, Tianxiang; Du, Zhengping; Wang, Qingguo

    2009-09-01

    In the construction of DEM, terrain features (e.g. valleys or stream lines, ridges, peaks, saddle points) are important for improving DEM accuracy and saw many applications in hydrology, precision agriculture, military trajectory planning, etc. HASM (High Accuracy Surface Modeling) is a method for surface modeling, which is based on the theory of surface. Presently, HASM is only used for scattered point's interpolation. So the work in this paper attempts to construct DEM based on the characteristic terrain information as stream lines and scattered points by HASM method. The course is described as the following steps. Firstly TIN (Triangulated Irregular Network) from the scattered points is generated. Secondly, each segment of the stream lines is well oriented to represent stream lines' flow direction, and a tree data structure (that has parent, children and brothers) is used to represent the whole stream lines' segments. A segment is a curve which does not intersect with other segments. A Water Course Flow (WCF) line is a set of segment lines connected piecewise but without overlapping or repetition, from the most upper reaches to the most lower reaches. From the stream lines' tree data structure, all the possible WCF lines are enumerated, and the start point and end point of each WCF lines is predicted from searching among the TIN. Thirdly, given a cell size, a 2-D matrix for the research region is built, and the values of the cells who were traversed by the stream lines by linear interpolation among each WCF lines. Fourthly, all the valued cells that were passed through by the stream line and that were from the scattered points are gathered as known scattered sampling points, and then HASM is used to construct the final DEM. A case study on the typical landform of plateau of China, KongTong gully of Dongzhi Plateau, Qingyang, Gausu province, is presented. The original data is manually vecterized from scanned maps 1:10,000, includes scattered points, stream lines, contour lines, precipitous cliff lines of a region of area about 4×5 square km. For simplicity only the former two kinds of data sources are used. By Comparing with the result from stream-line-constrained TIN and hydrologically correct DEM construction method Thin plate Spline (TPS, that is implemented as command TopoToRaster in ArcGIS 9.0 and later version)through visual inspection, HASM gets a more desirable DEM and more reasonable integration of information of the terrain features. Finally, some challenges and future research about HASM is also given.

  3. Constructing DEM from characteristic terrain information using HASM method

    NASA Astrophysics Data System (ADS)

    Song, Dunjiang; Yue, Tianxiang; Du, Zhengping; Wang, Qingguo

    2010-11-01

    In the construction of DEM, terrain features (e.g. valleys or stream lines, ridges, peaks, saddle points) are important for improving DEM accuracy and saw many applications in hydrology, precision agriculture, military trajectory planning, etc. HASM (High Accuracy Surface Modeling) is a method for surface modeling, which is based on the theory of surface. Presently, HASM is only used for scattered point's interpolation. So the work in this paper attempts to construct DEM based on the characteristic terrain information as stream lines and scattered points by HASM method. The course is described as the following steps. Firstly TIN (Triangulated Irregular Network) from the scattered points is generated. Secondly, each segment of the stream lines is well oriented to represent stream lines' flow direction, and a tree data structure (that has parent, children and brothers) is used to represent the whole stream lines' segments. A segment is a curve which does not intersect with other segments. A Water Course Flow (WCF) line is a set of segment lines connected piecewise but without overlapping or repetition, from the most upper reaches to the most lower reaches. From the stream lines' tree data structure, all the possible WCF lines are enumerated, and the start point and end point of each WCF lines is predicted from searching among the TIN. Thirdly, given a cell size, a 2-D matrix for the research region is built, and the values of the cells who were traversed by the stream lines by linear interpolation among each WCF lines. Fourthly, all the valued cells that were passed through by the stream line and that were from the scattered points are gathered as known scattered sampling points, and then HASM is used to construct the final DEM. A case study on the typical landform of plateau of China, KongTong gully of Dongzhi Plateau, Qingyang, Gausu province, is presented. The original data is manually vecterized from scanned maps 1:10,000, includes scattered points, stream lines, contour lines, precipitous cliff lines of a region of area about 4×5 square km. For simplicity only the former two kinds of data sources are used. By Comparing with the result from stream-line-constrained TIN and hydrologically correct DEM construction method Thin plate Spline (TPS, that is implemented as command TopoToRaster in ArcGIS 9.0 and later version)through visual inspection, HASM gets a more desirable DEM and more reasonable integration of information of the terrain features. Finally, some challenges and future research about HASM is also given.

  4. Improving the TanDEM-X DEM for flood modelling using flood extents from Synthetic Aperture Radar images.

    NASA Astrophysics Data System (ADS)

    Mason, David; Trigg, Mark; Garcia-Pintado, Javier; Cloke, Hannah; Neal, Jeffrey; Bates, Paul

    2015-04-01

    Many floodplains in the developed world have now been imaged with high resolution airborne LiDAR or InSAR, giving accurate DEMs that facilitate accurate flood inundation modelling. This is not always the case for remote rivers in developing countries. However, the accuracy of DEMs produced for modelling studies on such rivers should be enhanced in the near future by the high resolution TanDEM-X World DEM. In a parallel development, increasing use is now being made of flood extents derived from high resolution SAR images for calibrating, validating and assimilating observations into flood inundation models in order to improve these. The paper discusses an additional use of SAR flood extents to improve the accuracy of the TanDEM-X DEM in the floodplain covered by the flood extents, thereby permanently improving the DEM for future flood modelling studies in this area. The method is based on the fact that for larger rivers the water elevation changes only slowly along a reach, so that the boundary of the flood extent (the waterline) can be regarded locally as a quasi-contour. As a result, heights of adjacent pixels along a small section of waterline can be regarded as a sample of heights with a common population mean. The height of the central pixel in the section can be replaced with the average of these heights, leading to a more accurate height estimate. While this will result in a reduction in the height errors along a waterline, the waterline is a linear feature in a two-dimensional space. However, improvements to the DEM heights between adjacent pairs of waterlines can also be made, because DEM heights enclosed by the higher waterline of a pair must be at least no higher than the refined heights along the higher waterline, whereas DEM heights not enclosed by the lower waterline must be no lower than the refined heights along the lower waterline. In addition, DEM heights between the higher and lower waterlines can also be assigned smaller errors because of the reduced errors on the refined waterline heights. The method was tested on a section of the TanDEM-X Intermediate DEM (IDEM) covering an 11km reach of the Warwickshire Avon, England. Flood extents from four COSMO-SKyMed images were available at various stages of a flood in November 2012. Waterlines were detected automatically using the method described in [1]. The 12.5m resolution IDEM was re-sampled to the 2.5m resolution of the CSK images using nearest neighbour interpolation. Improvements to the IDEM were attempted only in regions of low slope and low vegetation, so that the DEM could be regarded as the DTM. The height of a pixel on a waterline was replaced by the average of the waterline pixel heights in an 11 x 11 IDEM pixel window centred on the current CSK pixel (but selecting only one waterline height per IDEM pixel to reduce correlations). Original and refined IDEM heights were compared to corresponding airborne LiDAR heights. Along the waterlines, it was found that the original IDEM heights had a standard deviation of 1.1m and a bias of 0.2m, while the refined heights had a standard deviation of only 0.6m and a similar bias. Between two adjacent waterlines, on average approximately 25% of IDEM heights were above the higher waterline, and 20% below the lower waterline. When compared to LiDAR, the original higher heights had a mean difference from the LiDAR height of 2.4m with standard deviation 3.0m, while after correction the mean difference was 0.5m with standard deviation 1.0m. The corrected heights below the lower waterline were similarly improved. The height errors of a further 40% of IDEM heights between the higher and lower waterlines were also reduced, because of the reduced errors on the refined waterline heights. 1. Mason DC, Davenport IJ, Neal JC, Schumann GJ-P and Bates PD (2012). Near real-time flood detection in urban and rural areas using high resolution Synthetic Aperture Radar images. IEEE. Trans. Geoscience Rem. Sens., 50(8), 3041-3052.

  5. Separability of soils in a tallgrass prairie using SPOT and DEM data

    NASA Technical Reports Server (NTRS)

    Su, Haiping; Ransom, Michel D.; Yang, Shie-Shien; Kanemasu, Edward T.

    1990-01-01

    An investigation is conducted which uses a canonical transformation technique to reduce the features from SPOT and DEM data and evaluates the statistical separability of several prairie soils from the canonically transformed variables. Both SPOT and DEM data was gathered for a tallgrass prairie near Manhattan, Kansas, and high resolution SPOT satellite images were integrated with DEM data. Two canonical variables derived from training samples were selected and it is suggested that canonically transformed data were superior to combined SPOT and DEM data. High resolution SPOT images and DEM data can be used to aid second-order soil surveys in grasslands.

  6. A description of rotations for DEM models of particle systems

    NASA Astrophysics Data System (ADS)

    Campello, Eduardo M. B.

    2015-06-01

    In this work, we show how a vector parameterization of rotations can be adopted to describe the rotational motion of particles within the framework of the discrete element method (DEM). It is based on the use of a special rotation vector, called Rodrigues rotation vector, and accounts for finite rotations in a fully exact manner. The use of fictitious entities such as quaternions or complicated structures such as Euler angles is thereby circumvented. As an additional advantage, stick-slip friction models with inter-particle rolling motion are made possible in a consistent and elegant way. A few examples are provided to illustrate the applicability of the scheme. We believe that simple vector descriptions of rotations are very useful for DEM models of particle systems.

  7. The Shuttle Radar Topography Mission: A Global DEM

    NASA Technical Reports Server (NTRS)

    Farr, Tom G.; Kobrick, Mike

    2000-01-01

    Digital topographic data are critical for a variety of civilian, commercial, and military applications. Scientists use Digital Elevation Models (DEM) to map drainage patterns and ecosystems, and to monitor land surface changes over time. The mountain-building effects of tectonics and the climatic effects of erosion can also be modeled with DEW The data's military applications include mission planning and rehearsal, modeling and simulation. Commercial applications include determining locations for cellular phone towers, enhanced ground proximity warning systems for aircraft, and improved maps for backpackers. The Shuttle Radar Topography Mission (SRTM) (Fig. 1), is a cooperative project between NASA and the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense. The mission is designed to use a single-pass radar interferometer to produce a digital elevation model of the Earth's land surface between about 60 degrees north and south latitude. The DEM will have 30 m pixel spacing and about 15 m vertical errors.

  8. Development of parallel DEM for the open source code MFIX

    SciTech Connect

    Gopalakrishnan, Pradeep; Tafti, Danesh

    2013-02-01

    The paper presents the development of a parallel Discrete Element Method (DEM) solver for the open source code, Multiphase Flow with Interphase eXchange (MFIX) based on the domain decomposition method. The performance of the code was evaluated by simulating a bubbling fluidized bed with 2.5 million particles. The DEM solver shows strong scalability up to 256 processors with an efficiency of 81%. Further, to analyze weak scaling, the static height of the fluidized bed was increased to hold 5 and 10 million particles. The results show that global communication cost increases with problem size while the computational cost remains constant. Further, the effects of static bed height on the bubble hydrodynamics and mixing characteristics are analyzed.

  9. The ?DE-?M Plane in Dark Energy Cosmology

    NASA Astrophysics Data System (ADS)

    Qiang, Yuan; Zhang, Tong-Jie

    The dark energy cosmology with the equation of state w=const. is considered in this paper. The ?DE-?M plane has been used to study the present state and expansion history of the universe. Through the mathematical analysis, we give the theoretical constraint of cosmological parameters. Together with some observations such as the transition redshift from deceleration to acceleration, more precise constraint on cosmological parameters can be acquired.

  10. BOREAS Regional DEM in Raster Format and AEAC Projection

    NASA Technical Reports Server (NTRS)

    Knapp, David; Verdin, Kristine; Hall, Forrest G. (Editor)

    2000-01-01

    This data set is based on the GTOPO30 Digital Elevation Model (DEM) produced by the United States Geological Survey EROS Data Center (USGS EDC). The BOReal Ecosystem-Atmosphere Study (BOREAS) region (1,000 km x 1000 km) was extracted from the GTOPO30 data and reprojected by BOREAS staff into the Albers Equal-Area Conic (AEAC) projection. The pixel size of these data is 1 km. The data are stored in binary, image format files.

  11. Development of a 'bare-earth' SRTM DEM product

    NASA Astrophysics Data System (ADS)

    O'Loughlin, Fiachra; Paiva, Rodrigo; Durand, Michael; Alsdorf, Douglas; Bates, Paul

    2015-04-01

    We present the methodology and results from the development of a near-global 'bare-earth' Digital Elevation Model (DEM) derived from the Shuttle Radar Topography Mission (SRTM) data. Digital Elevation Models are the most important input for hydraulic modelling, as the DEM quality governs the accuracy of the model outputs. While SRTM is currently the best near-globally [60N to 60S] available DEM, it requires adjustments to reduce the vegetation contamination and make it useful for hydrodynamic modelling over heavily vegetated areas (e.g. tropical wetlands). Unlike previous methods of accounting for vegetation contamination, which concentrated on correcting relatively small areas and usually applied a static adjustment, we account for vegetation contamination globally and apply a spatial varying correction, based on information about canopy height and density. In creating the final 'bare-earth' SRTM DEM dataset, we produced three different 'bare-earth' SRTM products. The first applies global parameters, while the second and third products apply parameters that are regionalised based on either climatic zones or vegetation types, respectively. We also tested two different canopy density proxies of different spatial resolution. Using ground elevations obtained from the ICESat GLA14 satellite altimeter, we calculate the residual errors for the raw SRTM and the three 'bare-earth' SRTM products and compare performances. The three 'bare-earth' products all show large improvements over the raw SRTM in vegetated areas with the overall mean bias reduced by between 75 and 92% from 4.94 m to 0.40 m. The overall standard deviation is reduced by between 29 and 33 % from 7.12 m to 4.80 m. As expected, improvements are higher in areas with denser vegetation. The final 'bare-earth' SRTM dataset is available at 3 arc-second with lower vertical height errors and less noise than the original SRTM product.

  12. Efficient parallel CFD-DEM simulations using OpenMP

    NASA Astrophysics Data System (ADS)

    Amritkar, Amit; Deb, Surya; Tafti, Danesh

    2014-01-01

    The paper describes parallelization strategies for the Discrete Element Method (DEM) used for simulating dense particulate systems coupled to Computational Fluid Dynamics (CFD). While the field equations of CFD are best parallelized by spatial domain decomposition techniques, the N-body particulate phase is best parallelized over the number of particles. When the two are coupled together, both modes are needed for efficient parallelization. It is shown that under these requirements, OpenMP thread based parallelization has advantages over MPI processes. Two representative examples, fairly typical of dense fluid-particulate systems are investigated, including the validation of the DEM-CFD and thermal-DEM implementation with experiments. Fluidized bed calculations are performed on beds with uniform particle loading, parallelized with MPI and OpenMP. It is shown that as the number of processing cores and the number of particles increase, the communication overhead of building ghost particle lists at processor boundaries dominates time to solution, and OpenMP which does not require this step is about twice as fast as MPI. In rotary kiln heat transfer calculations, which are characterized by spatially non-uniform particle distributions, the low overhead of switching the parallelization mode in OpenMP eliminates the load imbalances, but introduces increased overheads in fetching non-local data. In spite of this, it is shown that OpenMP is between 50-90% faster than MPI.

  13. Validation of DEM prediction for granular avalanches on irregular terrain

    NASA Astrophysics Data System (ADS)

    Mead, Stuart R.; Cleary, Paul W.

    2015-09-01

    Accurate numerical simulation can provide crucial information useful for a greater understanding of destructive granular mass movements such as rock avalanches, landslides, and pyroclastic flows. It enables more informed and relatively low cost investigation of significant risk factors, mitigation strategy effectiveness, and sensitivity to initial conditions, material, or soil properties. In this paper, a granular avalanche experiment from the literature is reanalyzed and used as a basis to assess the accuracy of discrete element method (DEM) predictions of avalanche flow. Discrete granular approaches such as DEM simulate the motion and collisions of individual particles and are useful for identifying and investigating the controlling processes within an avalanche. Using a superquadric shape representation, DEM simulations were found to accurately reproduce transient and static features of the avalanche. The effect of material properties on the shape of the avalanche deposit was investigated. The simulated avalanche deposits were found to be sensitive to particle shape and friction, with the particle shape causing the sensitivity to friction to vary. The importance of particle shape, coupled with effect on the sensitivity to friction, highlights the importance of quantifying and including particle shape effects in numerical modeling of granular avalanches.

  14. A simplified DEM numerical simulation of vibroflotation without backfill

    NASA Astrophysics Data System (ADS)

    Jiang, M. J.; Liu, W. W.; He, J.; Sun, Y.

    2015-09-01

    Vibroflotation is one of the deep vibratory compaction techniques for ground reinforcement. This method densities the soil and improves its mechanical properties, thus helps to protect people's lives and property from geological disasters. The macro reinforcement mechanisms of vibroflotation method have been investigated by numerical simulations, laboratory and in-situ experiments. However, little attention has been paid on its micro - mechanism, which is essential to fully understand the principle of the ground reinforcement. Discrete element method (DEM), based on discrete mechanics, is more powerful to solve large deformation and failure problems. This paper investigated the macro-micro mechanism of vibroflotation without backfill under two conditions, i.e., whether or not the ground water was considered, by incorporating inter-particle rolling resistance model in the DEM simulations. Conclusions obtained are as follows: The DEM simulations incorporating rolling resistance well replicate the mechanical response of the soil assemblages and are in line with practical observations. The void ratio of the granular soil fluctuates up and down in the process of vibroflotation, and finally reduces to a lower value. It is more efficient to densify the ground without water compared to the ground with water.

  15. Interpolation and elevation errors: the impact of the DEM resolution

    NASA Astrophysics Data System (ADS)

    Achilleos, Georgios A.

    2015-06-01

    Digital Elevation Models (DEMs) are developing and evolving at a fast pace, given the progress of computer science and technology. This development though, is not accompanied by an advancement of knowledge on the quality of the models and their indigenous inaccuracy. The user on most occasions is not aware of this quality thus in not aware of the correlating product uncertainty. Extensive research has been conducted - and still is - towards this direction. In the research presented in this paper there is an analysis of elevation errors behavior which are recorded in a DEM. The behavior of these elevation errors, is caused by altering the DEM resolution upon the application of the algorithm interpolation. Contour lines are used as entry data from a topographical map. Elevation errors are calculated in the positions of the initial entry data and wherever the elevation is known. The elevation errors that are recorded, are analyzed, in order to reach conclusions about their distribution and the way in which they occur.

  16. Application research of terrain based on DEM and data mining

    NASA Astrophysics Data System (ADS)

    Yu, Ming; Chen, Xiaoyu; Ai, Tinghua

    2007-06-01

    Terrain is one of the essential elements on geography. A Digital Elevation Model (DEM) is one of the methods to represent the elevation of the earth's surface. It contains abundant landform information. It is very important that we can extract relevant information form DEM for GIS to analyze and apply. And it is very meaning that Mini-watersheds are classed with data mining yielding knowledge. This paper shows that some problems can be addressed using GIS technology. Firstly, TIN and DEM are formed. Secondly, 28 Mini-watershed of the study area separated by Hydrology Analysis and factors of other terrain are extracted. Such as drainage density, average slope, average slope length and topographic relief. Thirdly, Mini-watersheds are classed again by clustering based on data collecting C5.0 (Algorithm). In the end, model are set up and discussed. In this paper, we have discussed that (a)the topological gurgitation and slope grade relation great with each other (0.93); (b)most Mini-watershed are orientation south; (c) the results and models showed correlation clearly between terrain and agriculture landuse in the study area.

  17. A coupled DEM-CFD method for impulse wave modelling

    NASA Astrophysics Data System (ADS)

    Zhao, Tao; Utili, Stefano; Crosta, GiovanBattista

    2015-04-01

    Rockslides can be characterized by a rapid evolution, up to a possible transition into a rock avalanche, which can be associated with an almost instantaneous collapse and spreading. Different examples are available in the literature, but the Vajont rockslide is quite unique for its morphological and geological characteristics, as well as for the type of evolution and the availability of long term monitoring data. This study advocates the use of a DEM-CFD framework for the modelling of the generation of hydrodynamic waves due to the impact of a rapid moving rockslide or rock-debris avalanche. 3D DEM analyses in plane strain by a coupled DEM-CFD code were performed to simulate the rockslide from its onset to the impact with still water and the subsequent wave generation (Zhao et al., 2014). The physical response predicted is in broad agreement with the available observations. The numerical results are compared to those published in the literature and especially to Crosta et al. (2014). According to our results, the maximum computed run up amounts to ca. 120 m and 170 m for the eastern and western lobe cross sections, respectively. These values are reasonably similar to those recorded during the event (i.e. ca. 130 m and 190 m respectively). In these simulations, the slope mass is considered permeable, such that the toe region of the slope can move submerged in the reservoir and the impulse water wave can also flow back into the slope mass. However, the upscaling of the grains size in the DEM model leads to an unrealistically high hydraulic conductivity of the model, such that only a small amount of water is splashed onto the northern bank of the Vajont valley. The use of high fluid viscosity and coarse grain model has shown the possibility to model more realistically both the slope and wave motions. However, more detailed slope and fluid properties, and the need for computational efficiency should be considered in future research work. This aspect has also been investigated by Crosta et al. (2014) via 2D and 3D FEM ALE modelling without considering the water seepage in the slope mass has been used. Their results can be a good way to estimate the slope and wave motion for fast sliding conditions. The 3D modelling can also clarify the lateral motion of water and estimate the potential risk of water overtopping the dam crest. The DEM and FEM ALE modelling can be used together to analyse fast moving rockslides (i.e. flowslides, rockslides, rock and debris avalanches) both in dry conditions and for their interaction with water basins. References Zhao, T., Utili, S., Crosta, G.B. Rockslide and impulse wave modelling in the Vajont reservoir by DEM-CFD analyses. Rock Mechanics and rock Engineering, under review. Crosta, G.B., Imposimato, S. & Roddeman, D. 2014. Landslide spreading, impulse waves and modelling of the Vajont rockslide. Rock Mechanics and Rock Engineering, under review.

  18. 3D DEM analyses of the 1963 Vajont rock slide

    NASA Astrophysics Data System (ADS)

    Boon, Chia Weng; Houlsby, Guy; Utili, Stefano

    2013-04-01

    The 1963 Vajont rock slide has been modelled using the distinct element method (DEM). The open-source DEM code, YADE (Kozicki & Donzé, 2008), was used together with the contact detection algorithm proposed by Boon et al. (2012). The critical sliding friction angle at the slide surface was sought using a strength reduction approach. A shear-softening contact model was used to model the shear resistance of the clayey layer at the slide surface. The results suggest that the critical sliding friction angle can be conservative if stability analyses are calculated based on the peak friction angles. The water table was assumed to be horizontal and the pore pressure at the clay layer was assumed to be hydrostatic. The influence of reservoir filling was marginal, increasing the sliding friction angle by only 1.6?. The results of the DEM calculations were found to be sensitive to the orientations of the bedding planes and cross-joints. Finally, the failure mechanism was investigated and arching was found to be present at the bend of the chair-shaped slope. References Boon C.W., Houlsby G.T., Utili S. (2012). A new algorithm for contact detection between convex polygonal and polyhedral particles in the discrete element method. Computers and Geotechnics, vol 44, 73-82, doi.org/10.1016/j.compgeo.2012.03.012. Kozicki, J., & Donzé, F. V. (2008). A new open-source software developed for numerical simulations using discrete modeling methods. Computer Methods in Applied Mechanics and Engineering, 197(49-50), 4429-4443.

  19. In need of combined topography and bathymetry DEM

    NASA Astrophysics Data System (ADS)

    Kisimoto, K.; Hilde, T.

    2003-04-01

    In many geoscience applications, digital elevation models (DEMs) are now more commonly used at different scales and greater resolution due to the great advancement in computer technology. Increasing the accuracy/resolution of the model and the coverage of the terrain (global model) has been the goal of users as mapping technology has improved and computers get faster and cheaper. The ETOPO5 (5 arc minutes spatial resolution land and seafloor model), initially developed in 1988 by Margo Edwards, then at Washington University, St. Louis, MO, has been the only global terrain model for a long time, and it is now being replaced by three new topographic and bathymetric DEMs, i.e.; the ETOPO2 (2 arc minutes spatial resolution land and seafloor model), the GTOPO30 land model with a spatial resolution of 30 arc seconds (c.a. 1km at equator) and the 'GEBCO 1-MINUTE GLOBAL BATHYMETRIC GRID' ocean floor model with a spatial resolution of 1 arc minute (c.a. 2 km at equator). These DEMs are products of projects through which compilation and reprocessing of existing and/or new datasets were made to meet user's new requirements. These ongoing efforts are valuable and support should be continued to refine and update these DEMs. On the other hand, a different approach to create a global bathymetric (seafloor) database exists. A method to estimate the seafloor topography from satellite altimetry combined with existing ships' conventional sounding data was devised and a beautiful global seafloor database created and made public by W.H. Smith and D.T. Sandwell in 1997. The big advantage of this database is the uniformity of coverage, i.e. there is no large area where depths are missing. It has a spatial resolution of 2 arc minute. Another important effort is found in making regional, not global, seafloor databases with much finer resolutions in many countries. The Japan Hydrographic Department has compiled and released a 500m-grid topography database around Japan, J-EGG500, in 1999. Although the coverage of this database is only a small portion of the Earth, the database has been highly appreciated in the academic community, and accepted in surprise by the general public when the database was displayed in 3D imagery to show its quality. This database could be rather smoothly combined with the finer land DEM of 250m spatial resolution (Japan250m.grd, K. Kisimoto, 2000). One of the most important applications of this combined DEM of topography and bathymetry is tsunami modeling. Understanding of the coastal environment, management and development of the coastal region are other fields in need of these data. There is, however, an important issue to consider when we create a combined DEM of topography and bathymetry in finer resolutions. The problem arises from the discrepancy of the standard datum planes or reference levels used for topographic leveling and bathymetric sounding. Land topography (altitude) is defined by leveling from the single reference point determined by average mean sea level, in other words, land height is measured from the geoid. On the other hand, depth charts are made based on depth measured from locally determined reference sea surface level, and this value of sea surface level is taken from the long term average of the lowest tidal height. So, to create a combined DEM of topography and bathymetry in very fine scale, we need to avoid this inconsistency between height and depth across the coastal region. Height and depth should be physically continuous relative to a single reference datum across the coast within such new high resolution DEMs. (N.B. Coast line is not equal to 'altitude-zero line' nor 'depth-zero line'. It is defined locally as the long term average of the highest tide level.) All of this said, we still need a lot of work on the ocean side. Global coverage with detailed bathymetric mapping is still poor. Seafloor imaging and other geophysical measurements/experiments should be organized and conducted internationally and interdisciplinary ways more than ever. We always need greater technological advancement

  20. Accuracy of Cartosat-1 DEM and its derived attribute at multiple scale representation

    NASA Astrophysics Data System (ADS)

    Mukherjee, Samadrita; Mukherjee, Sandip; Bhardwaj, A.; Mukhopadhyay, Anirban; Garg, R. D.; Hazra, S.

    2015-04-01

    Digital Elevation Model (DEM) provides basic information about terrain relief and is used for morphological characterisation, hydrological modelling and infrastructural studies. This paper investigates the accuracy of DEM and its derived attributes in multiple scales. This study was carried out for a part of Shiwalik Himalaya using Cartosat-1 stereo pair data. DEM at various cell sizes were generated and information content was compared using mean elevation, variance and entropy statistics. Various post-spacing DEMs were validated to understand variation in vertical accuracy along different scales. The vertical accuracy (3.14-7.24 m) is affected in larger spacing DEM and elevation is underestimated. Slope of terrain also has similar impacts. The DEM and slope accuracy are also affected by the terrain roughness while assessing coarser grid size.

  1. Solar DEM Models : A solar image in color band b, mn pixels,

    E-print Network

    Wolfe, Patrick J.

    Solar DEM Models : A solar image in color band b, m×n pixels, containing a particular solar feature, for t = 1, 2, . . . , T. btM sianFieldRandomGaus I M I I bbb T t bbtt bbb bb 2 1 2 )( #12;Solar DEM.bI : the measure error of the ith row and jth column pixel of the certain image in color band b. ijbe #12;Solar DEM

  2. A photogrammetric DEM of Greenland based on 1978-1987 aerial photos: validation and integration with laser altimetry and satellite-derived DEMs

    NASA Astrophysics Data System (ADS)

    Korsgaard, N. J.; Kjaer, K. H.; Nuth, C.; Khan, S. A.

    2014-12-01

    Here we present a DEM of Greenland covering all ice-free terrain and the margins of the GrIS and local glaciers and ice caps. The DEM is based on the 3534 photos used in the aero-triangulation which were recorded by the Danish Geodata Agency (then the Geodetic Institute) in survey campaigns spanning the period 1978-1987. The GrIS is covered tens of kilometers into the interior due to the large footprints of the photos (30 x 30 km) and control provided by the aero-triangulation. Thus, the data are ideal for providing information for analysis of ice marginal elevation change and also control for satellite-derived DEMs.The results of the validation, error assessments and predicted uncertainties are presented. We test the DEM using Airborne Topographic Mapper (IceBridge ATM) as reference data; evaluate the a posteriori covariance matrix from the aero-triangulation; and co-register DEM blocks of 50 x 50 km to ICESat laser altimetry in order to evaluate the coherency.We complement the aero-photogrammetric DEM with modern laser altimetry and DEMs derived from stereoscopic satellite imagery (AST14DMO) to examine the mass variability of the Northeast Greenland Ice Stream (NEGIS). Our analysis suggests that dynamically-induced mass loss started around 2003 and continued throughout 2014.

  3. A seamless, high-resolution digital elevation model (DEM) of the north-central California coast

    USGS Publications Warehouse

    Foxgrover, Amy C.; Barnard, Patrick L.

    2012-01-01

    A seamless, 2-meter resolution digital elevation model (DEM) of the north-central California coast has been created from the most recent high-resolution bathymetric and topographic datasets available. The DEM extends approximately 150 kilometers along the California coastline, from Half Moon Bay north to Bodega Head. Coverage extends inland to an elevation of +20 meters and offshore to at least the 3 nautical mile limit of state waters. This report describes the procedures of DEM construction, details the input data sources, and provides the DEM for download in both ESRI Arc ASCII and GeoTIFF file formats with accompanying metadata.

  4. Influence of DEM resolution on drainage network extraction: A multifractal analysis

    NASA Astrophysics Data System (ADS)

    Ariza-Villaverde, A. B.; Jiménez-Hornero, F. J.; Gutiérrez de Ravé, E.

    2015-07-01

    Different hydrological algorithms have been developed to automatically extract drainage networks from digital elevation models (DEMs). D8 is the most widely used algorithm to delineate drainage networks and catchments from a DEM. This algorithm has certain advantages such as simplicity, the provision of a reasonable representation for convergent flow conditions and consistency among flow patterns, calculated contributing areas and the spatial representation of subcatchments. However, it has limitations in selecting suitable flow accumulation threshold values to determine the pixels that belong to drainage networks. Although the effects of DEM resolution on some terrain attributes, stream characterisation and watershed delineation have been studied, analyses of the influence of DEM resolution on flow accumulation threshold values have been limited. Recently, multifractal analyses have been successfully used to find appropriate flow accumulation threshold values. The application of this type of analysis to evaluate the relationship between DEM resolution and flow accumulation threshold value needs to be explored. Therefore, this study tested three DEM resolutions for four drainage basins with different levels of drainage network distribution by comparing the Rényi spectra of the drainage networks that were obtained with the D8 algorithm against those determined by photogrammetric restitution. According to the results, DEM resolution influences the selected flow accumulation threshold value and the simulated network morphology. The suitable flow accumulation threshold value increases as the DEM resolution increases and shows greater variability for basins with lower drainage densities. The links between DEM resolution and terrain attributes were also examined.

  5. DEM, tide and velocity over sulzberger ice shelf, West Antarctica

    USGS Publications Warehouse

    Baek, S.; Shum, C.K.; Lee, H.; Yi, Y.; Kwoun, Oh-Ig; Lu, Zhiming; Braun, Andreas

    2005-01-01

    Arctic and Antarctic ice sheets preserve more than 77% of the global fresh water and could raise global sea level by several meters if completely melted. Ocean tides near and under ice shelves shifts the grounding line position significantly and are one of current limitations to study glacier dynamics and mass balance. The Sulzberger ice shelf is an area of ice mass flux change in West Antarctica and has not yet been well studied. In this study, we use repeat-pass synthetic aperture radar (SAR) interferometry data from the ERS-1 and ERS-2 tandem missions for generation of a high-resolution (60-m) Digital Elevation Model (DEM) including tidal deformation detection and ice stream velocity of the Sulzberger Ice Shelf. Other satellite data such as laser altimeter measurements with fine foot-prints (70-m) from NASA's ICESat are used for validation and analyses. The resulting DEM has an accuracy of-0.57??5.88 m and is demonstrated to be useful for grounding line detection and ice mass balance studies. The deformation observed by InSAR is found to be primarily due to ocean tides and atmospheric pressure. The 2-D ice stream velocities computed agree qualitatively with previous methods on part of the Ice Shelf from passive microwave remote-sensing data (i.e., LANDSAT). ?? 2005 IEEE.

  6. Simulation of triaxial response of granular materials by modified DEM

    NASA Astrophysics Data System (ADS)

    Wang, XiaoLiang; Li, JiaChun

    2014-12-01

    A modified discrete element method (DEM) with rolling effect taken into consideration is developed to examine macroscopic behavior of granular materials in this study. Dimensional analysis is firstly performed to establish the relationship between macroscopic mechanical behavior, mesoscale contact parameters at particle level and external loading rate. It is found that only four dimensionless parameters may govern the macroscopic mechanical behavior in bulk. The numerical triaxial apparatus was used to study their influence on the mechanical behavior of granular materials. The parametric study indicates that Poisson's ratio only varies with stiffness ratio, while Young's modulus is proportional to contact modulus and grows with stiffness ratio, both of which agree with the micromechanical model. The peak friction angle is dependent on both inter-particle friction angle and rolling resistance. The dilatancy angle relies on inter-particle friction angle if rolling stiffness coefficient is sufficiently large. Finally, we have recommended a calibration procedure for cohesionless soil, which was at once applied to the simulation of Chende sand using a series of triaxial compression tests. The responses of DEM model are shown in quantitative agreement with experiments. In addition, stress-strain response of triaxial extension was also obtained by numerical triaxial extension tests.

  7. Extraction of Hydrological Proximity Measures from DEMs using Parallel Processing

    SciTech Connect

    Tesfa, Teklu K.; Tarboton, David G.; Watson, Daniel W.; Schreuders, Kimberly A.; Baker, Matthew M.; Wallace, Robert M.

    2011-12-01

    Land surface topography is one of the most important terrain properties which impact hydrological, geomorphological, and ecological processes active on a landscape. In our previous efforts to develop a soil depth model based upon topographic and land cover variables, we extracted a set of hydrological proximity measures (HPMs) from a Digital Elevation Model (DEM) as potential explanatory variables for soil depth. These HPMs may also have other, more general modeling applicability in hydrology, geomorphology and ecology, and so are described here from a general perspective. The HPMs we derived are variations of the distance up to ridge points (cells with no incoming flow) and variations of the distance down to stream points (cells with a contributing area greater than a threshold), following the flow path. These HPMs were computed using the D-infinity flow model that apportions flow between adjacent neighbors based on the direction of steepest downward slope on the eight triangular facets constructed in a 3 x 3 grid cell window using the center cell and each pair of adjacent neighboring grid cells in turn. The D-infinity model typically results in multiple flow paths between 2 points on the topography, with the result that distances may be computed as the minimum, maximum or average of the individual flow paths. In addition, each of the HPMs, are calculated vertically, horizontally, and along the land surface. Previously, these HPMs were calculated using recursive serial algorithms which suffered from stack overflow problems when used to process large datasets, limiting the size of DEMs that could be analyzed using that method to approximately 7000 x 7000 cells. To overcome this limitation, we developed a message passing interface (MPI) parallel approach for calculating these HPMs. The parallel algorithms of the HPMs spatially partition the input grid into stripes which are each assigned to separate processes for computation. Each of those processes then uses a queue data structure to order the processing of cells so that each cell is visited only once and the cross-process communications that are a standard part of MPI are handled in an efficient manner. This parallel approach allows analysis of much larger DEMs as compared to the serial recursive algorithms. In this paper, we present the definitions of the HPMs, the serial and parallel algorithms used in their extraction and their potential applications in hydrology, geomorphology and ecology.

  8. HALBLEITERSENSOREN Begriffe wie das ,,Labor auf dem Chip" oder die ,,Elektronische Nase" begegnen uns

    E-print Network

    Moritz, Werner

    CHEMISCHE HALBLEITERSENSOREN Begriffe wie das ,,Labor auf dem Chip" oder die ,,Elektronische Nase" begegnen uns häufig in den Medien. Dies lässt manchmal den Eindruck entstehen, dass die chemische Analytik. Vergleicht man jedoch chemische Sensoren mit einem sehr einfachen Sensor, z.B. dem Temperatursensor, können

  9. Evaluating the influence of spatial resolutions of DEM on watershed runoff and sediment yield using SWAT

    NASA Astrophysics Data System (ADS)

    Reddy, A. Sivasena; Reddy, M. Janga

    2015-10-01

    Digital elevation model (DEM) of a watershed forms key basis for hydrologic modelling and its resolution plays a key role in accurate prediction of various hydrological processes. This study appraises the effect of different DEMs with varied spatial resolutions (namely TOPO 20 m, CARTO 30 m, ASTER 30 m, SRTM 90 m, GEO-AUS 500 m and USGS 1000 m) on hydrological response of watershed using Soil and Water Assessment Tool (SWAT) and applied for a case study of Kaddam watershed in India for estimating runoff and sediment yield. From the results of case study, it was observed that reach lengths, reach slopes, minimum and maximum elevations, sub-watershed areas, land use mapping areas within the sub-watershed and number of HRUs varied substantially due to DEM resolutions, and consequently resulted in a considerable variability in estimated daily runoff and sediment yields. It was also observed that, daily runoff values have increased (decreased) on low (high) rainy days respectively with coarser resolution of DEM. The daily sediment yield values from each sub-watershed decreased with coarser resolution of the DEM. The study found that the performance of SWAT model prediction was not influenced much for finer resolution DEMs up to 90 m for estimation of runoff, but it certainly influenced the estimation of sediment yields. The DEMs of TOPO 20 m and CARTO 30 m provided better estimates of sub-watershed areas, runoff and sediment yield values over other DEMs.

  10. Solar DEM Model Proposal : A solar image in color band b, mn pixels,

    E-print Network

    Wolfe, Patrick J.

    Solar DEM Model Proposal : A solar image in color band b, m×n pixels, containing a particular solar 11 )( #12;Solar DEM Model Proposal : the volume (abundance?) of ion ii : the proportion of the total volume at temperature t t T t bitt I i ib MIE 11 )( #12;Solar Dataset · 15 Filters.txt files

  11. A Multi-Pass Generation of DEM for Urban Zheng Cui, 2

    E-print Network

    Chen, Shu-Ching

    @cis.uab.edu Abstract--High quality DEM (Digital Elevation Model) is indispensable for a smart city nowadays. A large. The filtering results, such as terrain surfaces and building boundaries, are critical in many smart city for mobile social networks. The DEM can be generated by surveying the area. LIDAR (Light Detection

  12. Using ASTER and SRTM DEMs for studying geomorphology and glaciation in high mountain areas

    E-print Network

    Bolch, Tobias

    Using ASTER and SRTM DEMs for studying geomorphology and glaciation in high mountain areas Tobias, SRTM, geomorphology, glaciation, Andes, Hindu Kush, Tien Shan ABSTRACT: For selected peaks in high identifying debris-covered glaciers and geomorphologic forms and processes. Results show that ASTER/SRTM DEMs

  13. C-DEM: A Multi-Modal Query System for Drosophila Embryo Databases

    E-print Network

    Xing, Eric P.

    C-DEM: A Multi-Modal Query System for Drosophila Embryo Databases Fan Guo, Lei Li, Christos hindgut"). C-DEM is an online system for Drosophila (= fruit-fly) Embryo images Mining. It supports images (and keywords, and genes). The demo is on a real Drosophila Embryo database, with 10,204 images, 2

  14. Evaluating the influence of spatial resolutions of DEM on watershed runoff and sediment yield using SWAT

    NASA Astrophysics Data System (ADS)

    Reddy, A. Sivasena; Reddy, M. Janga

    2015-09-01

    Digital elevation model (DEM) of a watershed forms key basis for hydrologic modelling and its resolution plays a key role in accurate prediction of various hydrological processes. This study appraises the effect of different DEMs with varied spatial resolutions (namely TOPO 20 m, CARTO 30 m, ASTER 30 m, SRTM 90 m, GEO-AUS 500 m and USGS 1000 m) on hydrological response of watershed using Soil and Water Assessment Tool (SWAT) and applied for a case study of Kaddam watershed in India for estimating runoff and sediment yield. From the results of case study, it was observed that reach lengths, reach slopes, minimum and maximum elevations, sub-watershed areas, land use mapping areas within the sub-watershed and number of HRUs varied substantially due to DEM resolutions, and consequently resulted in a considerable variability in estimated daily runoff and sediment yields. It was also observed that, daily runoff values have increased (decreased) on low (high) rainy days respectively with coarser resolution of DEM. The daily sediment yield values from each sub-watershed decreased with coarser resolution of the DEM. The study found that the performance of SWAT model prediction was not influenced much for finer resolution DEMs up to 90 m for estimation of runoff, but it certainly influenced the estimation of sediment yields. The DEMs of TOPO 20 m and CARTO 30 m provided better estimates of sub-watershed areas, runoff and sediment yield values over other DEMs.

  15. A simple method to improve the SRTM DEM based on Landsat ETM+ Image

    NASA Astrophysics Data System (ADS)

    Cai, Xiaobin; Chen, Xiaoling; Li, Hui; Tian, Liqiao; Wu, Zhongyi

    2005-10-01

    Shuttle Radar Terrain Mission (SRTM) DEM has become one of digital topographic data sources of the earth because of its high spatial resolution and near-global coverage. However, its widely usage has been limited by some void areas occurred in SRTM DEM, which are mainly related to the water body, spikes or wells. Although they were modified into finished SRTM DEM by using a complicated process by National Geospatial-Intelligence Agency (NGA), in which a lot of void areas could be filled with correct data, some void areas still exited especially in the water area. In addition, the accuracy of the finished SRTM DEM might be hindered because of no global accurate DEM as a reference. And the finished SRTM DEM can't be freely downloaded from Internet also limits its usage in some extent. A simple method to create an edited SRTM DEM based-on Landsat ETM+ image was proposed in this paper. The unfinished SRTM data was firstly re-projected to the UTM projection for matching the Landsat ETM+ image in the same area. Secondly, through analyzing the spectral attributes of water, the water body was accurately extracted from Landsat ETM+ image by using the indices of NDWI and NDVI. Thirdly, the water body in the unfinished SRTM DEM was masked, and the water void areas and non-water void areas were finally separated. The water body void areas were filled with the surrounding minimum elevation data and the non-water void areas were filled by using the method of Kriging interpolation. The results showed that the proposed method could improve the unfinished SRTM DEM, which were proved to be better than CIAT edited SRTM DEM according to the comparison of both visual effect and statistical accuracy.

  16. APPENDIX II II.1 Goodwin Creek DEM, Land Use, Soil Type, and Watershed Definition at Different Spatial

    E-print Network

    Julien, Pierre Y.

    APPENDIX II II.1 Goodwin Creek DEM, Land Use, Soil Type, and Watershed Definition at Different-------------------------------------------------------------------------------------------------------II-2 Figure II.1.1 DEM, watershed definition, soil type, and land use at 30-m ------------------II-2 Figure II.1.2 DEM, watershed definition, soil type, and land use at 90-m ------------------II-3 Figure II

  17. Frank, A. U., and S. Timpf. 1995. Forschungsprojekte der Abteilung Geoinformation an der TU Wien. Nachrichten aus dem Karten-und

    E-print Network

    Timpf, Sabine

    . Nachrichten aus dem Karten- und Vermessungswesen 1 (113):51-63. Forschungsprojekte der Abteilung. Timpf. 1995. Forschungsprojekte der Abteilung Geoinformation an der TU Wien. Nachrichten aus dem Karten

  18. Assessment of Uncertainty Propagation from DEM's on Small Scale Typologically-Differentiated Landslide Susceptibility in Romania

    NASA Astrophysics Data System (ADS)

    Cosmin Sandric, Ionut; Chitu, Zenaida; Jurchescu, Marta; Malet, Jean-Philippe; Ciprian Margarint, Mihai; Micu, Mihai

    2015-04-01

    An increasing number of free and open access global digital elevation models has become available in the past 15 years and these DEMs have been widely used for the assessment of landslide susceptibility at medium and small scales. Even though the global vertical and horizontal accuracies of each DEM are known, what it is still unknown is the uncertainty that propagates from the first and second derivatives of DEMs, like slope gradient, into the final landslide susceptibility map For the present study we focused on the assessment of the uncertainty propagation from the following digital elevation models: SRTM 90m spatial resolution, ASTERDEM 30m spatial resolution, EUDEM 30m spatial resolution and the latest release SRTM 30m spatial resolution. From each DEM dataset the slope gradient was generated and used in the landslide susceptibility analysis. A restricted number of spatial predictors are used for landslide susceptibility assessment, represented by lithology, land-cover and slope, were the slope is the only predictor that changes with each DEM. The study makes use of the first national landslide inventory (Micu et al, 2014) obtained from compiling literature data, personal or institutional landslide inventories. The landslide inventory contains more than 27,900 cases classified in three main categories: slides flows and falls The results present landslide susceptibility maps obtained from each DEM and from the combinations of DEM datasets. Maps with uncertainty propagation at country level and differentiated by topographic regions from Romania and by landslide typology (slides, flows and falls) are obtained for each DEM dataset and for the combinations of these. An objective evaluation of each DEM dataset and a final map of landslide susceptibility and the associated uncertainty are provided

  19. Incorporating the effect of DEM resolution and accuracy for improved flood inundation mapping

    NASA Astrophysics Data System (ADS)

    Saksena, Siddharth; Merwade, Venkatesh

    2015-11-01

    Topography plays a major role in determining the accuracy of flood inundation areas. However, many areas in the United States and around the world do not have access to high quality topographic data in the form of Digital Elevation Models (DEM). For such areas, an improved understanding of the effects of DEM properties such as horizontal resolution and vertical accuracy on flood inundation maps may eventually lead to improved flood inundation modeling and mapping. This study attempts to relate the errors arising from DEM properties such as spatial resolution and vertical accuracy to flood inundation maps, and then use this relationship to create improved flood inundation maps from coarser resolution DEMs with low accuracy. The results from the five stream reaches used in this study show that water surface elevations (WSE) along the stream and the flood inundation area have a linear relationship with both DEM resolution and accuracy. This linear relationship is then used to extrapolate the water surface elevations from coarser resolution DEMs to get water surface elevations corresponding to a finer resolution DEM. Application of this approach show that improved results can be obtained from flood modeling by using coarser and less accurate DEMs, including public domain datasets such as the National Elevation Dataset and Shuttle Radar Topography Mission (SRTM) DEMs. The improvement in the WSE and its application to obtain better flood inundation maps is dependent on the study reach characteristics such as land use, valley shape, reach length and width. Application of the approach presented in this study on more reaches may lead to development of guidelines for flood inundation mapping using coarser resolution and less accurate topographic datasets.

  20. How does modifying a DEM to reflect known hydrology affect subsequent terrain analysis?

    NASA Astrophysics Data System (ADS)

    Callow, John Nikolaus; Van Niel, Kimberly P.; Boggs, Guy S.

    2007-01-01

    SummaryMany digital elevation models (DEMs) have difficulty replicating hydrological patterns in flat landscapes. Efforts to improve DEM performance in replicating known hydrology have included a variety of soft (i.e. algorithm-based approaches) and hard techniques, such as " Stream burning" or "surface reconditioning" (e.g. Agree or ANUDEM). Using a representation of the known stream network, these methods trench or mathematically warp the original DEM to improve how accurately stream position, stream length and catchment boundaries replicate known hydrological conditions. However, these techniques permanently alter the DEM and may affect further analyses (e.g. slope). This paper explores the impact that commonly used hydrological correction methods ( Stream burning, Agree.aml and ANUDEM v4.6.3 and ANUDEM v5.1) have on the overall nature of a DEM, finding that different methods produce non-convergent outcomes for catchment parameters (such as catchment boundaries, stream position and length), and differentially compromise secondary terrain analysis. All hydrological correction methods successfully improved calculation of catchment area, stream position and length as compared to using the DEM without any modification, but they all increased catchment slope. No single method performing best across all categories. Different hydrological correction methods changed elevation and slope in different spatial patterns and magnitudes, compromising the ability to derive catchment parameters and conduct secondary terrain analysis from a single DEM. Modification of a DEM to better reflect known hydrology can be useful, however knowledge of the magnitude and spatial pattern of the changes are required before using a DEM for subsequent analyses.

  1. Scenario-Based Validation of Moderate Resolution DEMs Freely Available for Complex Himalayan Terrain

    NASA Astrophysics Data System (ADS)

    Singh, Mritunjay Kumar; Gupta, R. D.; Snehmani; Bhardwaj, Anshuman; Ganju, Ashwagosha

    2015-07-01

    Accuracy of the Digital Elevation Model (DEM) affects the accuracy of various geoscience and environmental modelling results. This study evaluates accuracies of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global DEM Version-2 (GDEM V2), the Shuttle Radar Topography Mission (SRTM) X-band DEM and the NRSC Cartosat-1 DEM V1 (CartoDEM). A high resolution (1 m) photogrammetric DEM (ADS80 DEM), having a high absolute accuracy [1.60 m linear error at 90 % confidence (LE90)], resampled at 30 m cell size was used as reference. The overall root mean square error (RMSE) in vertical accuracy was 23, 73, and 166 m and the LE90 was 36, 75, and 256 m for ASTER GDEM V2, SRTM X-band DEM and CartoDEM, respectively. A detailed error analysis was performed for individual as well as combinations of different classes of aspect, slope, land-cover and elevation zones for the study area. For the ASTER GDEM V2, forest areas with North facing slopes (0°-5°) in the 4th elevation zone (3773-4369 m) showed minimum LE90 of 0.99 m, and barren with East facing slopes (>60°) falling under the 2nd elevation zone (2581-3177 m) showed maximum LE90 of 166 m. For the SRTM DEM, pixels with South-East facing slopes of 0°-5° in the 4th elevation zone covered with forest showed least LE90 of 0.33 m and maximum LE90 of 521 m was observed in the barren area with North-East facing slope (>60°) in the 4th elevation zone. In case of the CartoDEM, the snow pixels in the 2nd elevation zone with South-East facing slopes of 5°-15° showed least LE90 of 0.71 m and maximum LE90 of 1266 m was observed for the snow pixels in the 3rd elevation zone (3177-3773 m) within the South facing slope of 45°-60°. These results can be highly useful for the researchers using DEM products in various modelling exercises.

  2. SPH-DEM simulations of grain dispersion by liquid injection

    NASA Astrophysics Data System (ADS)

    Robinson, Martin; Luding, Stefan; Ramaioli, Marco

    2013-06-01

    We study the dispersion of an initially packed, static granular bed by the injection of a liquid jet. This is a relevant system for many industrial applications, including paint dispersion or food powder dissolution. Both decompaction and dispersion of the powder are not fully understood, leading to inefficiencies in these processes. Here we consider a model problem where the liquid jet is injected below a granular bed contained in a cylindrical cell. Two different initial conditions are considered: a two-phase case where the bed is initially fully immersed in the liquid and a three-phase case where the bed and cell are completely dry preceding the injection of the liquid. The focus of this contribution is the simulation of these model problems using a two-way coupled SPH-DEM granularliquid method [M. Robinson, M. Ramaioli, and S. Luding, submitted (2013) and http://arxiv.org/abs/1301.0752 (2013)]. This is a purely particle-based method without any prescribed mesh, well suited for this and other problems involving a free (liquidgas) surface and a partly immersed particle phase. Our simulations show the effect of process parameters such as injection flow rate and injection diameter on the dispersion pattern, namely whether the granular bed is impregnated bottom-up or a jet is formed and compare well with experiments.

  3. Evaluation of DEM generation accuracy from UAS imagery

    NASA Astrophysics Data System (ADS)

    Santise, M.; Fornari, M.; Forlani, G.; Roncella, R.

    2014-06-01

    The growing use of UAS platform for aerial photogrammetry comes with a new family of Computer Vision highly automated processing software expressly built to manage the peculiar characteristics of these blocks of images. It is of interest to photogrammetrist and professionals, therefore, to find out whether the image orientation and DSM generation methods implemented in such software are reliable and the DSMs and orthophotos are accurate. On a more general basis, it is interesting to figure out whether it is still worth applying the standard rules of aerial photogrammetry to the case of drones, achieving the same inner strength and the same accuracies as well. With such goals in mind, a test area has been set up at the University Campus in Parma. A large number of ground points has been measured on natural as well as signalized points, to provide a comprehensive test field, to check the accuracy performance of different UAS systems. In the test area, points both at ground-level and features on the buildings roofs were measured, in order to obtain a distributed support also altimetrically. Control points were set on different types of surfaces (buildings, asphalt, target, fields of grass and bumps); break lines, were also employed. The paper presents the results of a comparison between two different surveys for DEM (Digital Elevation Model) generation, performed at 70 m and 140 m flying height, using a Falcon 8 UAS.

  4. Investigation of the Critical State in Soil Mechanics Using DEM

    SciTech Connect

    Pena, Andres A.; Garcia-Rojo, Ramon; Alonso-Marroquin, Fernando; Herrmann, Hans J.

    2009-06-18

    The existence and uniqueness of the so-called critical state in soil mechanics is validated in our DEM simulations of irregular polygonal particles. For different particle shape characteristics, the critical state is independent of the initial stress and density conditions. We retain low stress levels, since we do not take into account the crushing of particles. In biaxial test simulations isotropic particles evolve toward a limiting state in which the system reaches a critical void ratio and deforms with constant volume, deviatoric stress, fabric anisotropy, and mechanical coordination number. The last one has been found to be the first variable to attain a critical value making possible for the rest of micro-and-macro-mechanical variables the convergence to the critical state. In periodic shear cell tests, for large shear deformations samples with anisotropic particles reach at the macro-mechanical level the same critical value for both shear force and void ratio. At the micro-mechanical level the components of the stress tensor, the fabric tensor and the inertia tensor of the particles also reach the same stationary state. By varying the aspect ratio of the particles we stated the strong influence of particle shape anisotropy on the parameters that the granular packing attained at the critical state.

  5. TecDEM: A MATLAB based toolbox for tectonic geomorphology, Part 1: Drainage network preprocessing and stream profile analysis

    NASA Astrophysics Data System (ADS)

    Shahzad, Faisal; Gloaguen, Richard

    2011-02-01

    We present TecDEM, a software shell implemented in MATLAB that applies tectonic geomorphologic tasks to digital elevation models (DEMs). The first part of this paper series describes drainage partitioning schemes and stream profile analysis. The graphical user interface of TecDEM provides several options: determining flow directions, stream vectorization, watershed delineation, Strahler order labeling, stream profile generation, knickpoints selection, Concavity, Steepness and Hack indices calculations. The knickpoints along selected streams as well as stream profile analysis, and Hack index per stream profile are computed using a semi-automatic method. TecDEM was used to extract and investigate the stream profiles in the Kaghan Valley (Northern Pakistan). Our interpretations of the TecDEM results correlate well with previous tectonic evolution models for this region. TecDEM is designed to assist geoscientists in applying complex tectonic geomorphology tasks to global DEM data.

  6. What is the effect of LiDAR-derived DEM resolution on large-scale watershed model results?

    SciTech Connect

    Ping Yang; Daniel B. Ames; Andre Fonseca; Danny Anderson; Rupesh Shrestha; Nancy F. Glenn; Yang Cao

    2014-08-01

    This paper examines the effect of raster cell size on hydrographic feature extraction and hydrological modeling using LiDAR derived DEMs. LiDAR datasets for three experimental watersheds were converted to DEMs at various cell sizes. Watershed boundaries and stream networks were delineated from each DEM and were compared to reference data. Hydrological simulations were conducted and the outputs were compared. Smaller cell size DEMs consistently resulted in less difference between DEM-delineated features and reference data. However, minor differences been found between streamflow simulations resulted for a lumped watershed model run at daily simulations aggregated at an annual average. These findings indicate that while higher resolution DEM grids may result in more accurate representation of terrain characteristics, such variations do not necessarily improve watershed scale simulation modeling. Hence the additional expense of generating high resolution DEM's for the purpose of watershed modeling at daily or longer time steps may not be warranted.

  7. Automated sinkhole detection using a DEM subsetting technique and fill tools at Mammoth Cave National Park

    NASA Astrophysics Data System (ADS)

    Wall, J.; Bohnenstiehl, D. R.; Levine, N. S.

    2013-12-01

    An automated workflow for sinkhole detection is developed using Light Detection and Ranging (Lidar) data from Mammoth Cave National Park (MACA). While the park is known to sit within a karst formation, the generally dense canopy cover and the size of the park (~53,000 acres) creates issues for sinkhole inventorying. Lidar provides a useful remote sensing technology for peering beneath the canopy in hard to reach areas of the park. In order to detect sinkholes, a subsetting technique is used to interpolate a Digital Elevation Model (DEM) thereby reducing edge effects. For each subset, standard GIS fill tools are used to fill depressions within the DEM. The initial DEM is then subtracted from the filled DEM resulting in detected depressions or sinkholes. Resulting depressions are then described in terms of size and geospatial trend.

  8. IPY: An excellent opportunity to improve Arctic DEMs and document today's Arctic for future generations

    NASA Astrophysics Data System (ADS)

    Nolan, M.

    2003-12-01

    Digital Elevation Models (DEMs) are an essential resource for any field or modeling study in the terrestrial Arctic, yet the DEMs available there are currently the worst on the planet. Efforts in the past decade have led to the acquisition of new DEMs for the entire Antarctic continent (Radarsat Antarctic Mapping Project, RAMP) and for nearly all of the planet within +/- 60 degrees latitude (Space Shuttle Radar Topography Mission, SRTM). Thus, the U.S. Arctic is left with 1:63,360 maps made during the IGY times, which does not meet the USGS' own standards for accuracy. Other countries are left in similar circumstances, with DEMs created from paper maps with usually no better than 1:50,000 scale, and there is as yet no central circum-polar clearinghouse for such DEMs. And because nearly all of these DEMs were created by digitizing paper base maps, most contain artifacts of the digitizing process that further reduce their quality. It could be argued that DEMs of the polar regions of the planet Mars are more accurate, consistent, and easily available than those from the Earth's Arctic. Only an organized international effort could possibly manage such a data collection task, and the project seems well suited to the goals of the International Polar Year. Perhaps being last in line for new DEMs is actually beneficial in this case, as technological improvements have led to new acquisition systems that are more accurate than those used in SRTM and RAMP. For example, airborne synthetic aperture radar (SAR) interferometry has demonstrated the capability to acquire DEMs with 5 meter postings, 1 cm vertical resolution, and 2 m vertical accuracies, in addition to an orthorectified radar backscatter image at 2.5 meter postings; compare this with the 60m x 90m posting available currently and no associated orthoimagery. That is, for the price of an Arctic DEM, we would also get a picture of the Arctic at 2.5 meter resolution, and this picture can be merged with color Landsat to create stunning orthorectified images. These SAR systems, flying on a LearJet, can rapidly acquire day or night in a wide range of weather, eliminating most of the logistical delays common to other systems. Airborne Lidar, a laser based system, is also advanced to the stage where near-shore coastal bathymetry can be measured, such that we could seamlessly integrate DEMs and bathymetry. While the price of such acquisitions is high, it is comparable to DEM acquisitions on the rest of the planet and Mars, and the benefits would be enormous to a wide variety of polar researchers - perfect for the IPY. Presented in this poster will be several examples of how new DEMs have improved our Arctic research at UAF. McCall Glacier was originally an IGY field site and now has the longest record of mass balance observations of any glacier in the US Arctic, but our measurement program is hampered by the lack of decent topographic maps there. Our research using a new DEM in the Kuparuk River watershed in Alaska has shown that these DEMs substantially improve our hydrological modeling in such low gradient watersheds. With DEMs of such high accuracy and resolution, we can also begin a program of repeat-topographic mapping, to document changes not only to glaciers, but subtler permafrost phenomena with decimeter-scale changes such as pingos, thermokarsts, polygons, and oriented lakes. The time to acquire such data is now, however, before widespread changes occur. Thus the upcoming IPY can perhaps leave no better legacy than to replace the IGY-era, mediocre topographic maps with an accurate, high-resolution digital elevation model representing today's Arctic, which will remain valuable to generations of polar scientists.

  9. Radar Beam Occultation Studies Using GIS and DEM Technology: An Example Study of Guam

    E-print Network

    Kucera, Paul A.; Krajewski, Witold F.; Young, Bryan

    2004-07-01

    Geographic information systems (GISs) combined with digital elevation models (DEMs) provide opportunities to evaluate weather radar beam blockage and other ground clutter phenomena. The authors explore this potential using ...

  10. Hydrologic validation of a structure-from-motion DEM derived from low-altitude UAV imagery

    NASA Astrophysics Data System (ADS)

    Steiner, Florian; Marzolff, Irene; d'Oleire-Oltmanns, Sebastian

    2015-04-01

    The increasing ease of use of current Unmanned Aerial Vehicles (UAVs) and 3D image processing software has spurred the number of applications relying on high-resolution topographic datasets. Of particular significance in this field is "structure from motion" (SfM), a photogrammetric technique used to generate low-cost digital elevation models (DEMs) for erosion budgeting, measuring of glaciers/lava-flows, archaeological applications and others. It was originally designed to generate 3D-models of buildings, based on unordered collections of images and has become increasingly common in geoscience applications during the last few years. Several studies on the accuracy of this technique already exist, in which the SfM data is mostly compared with Lidar-generated terrain data. The results are mainly positive, indicating that the technique is suitable for such applications. This work aims at validating very high resolution SfM DEMs with a different approach: Not the original elevation data is validated, but data on terrain-related hydrological and geomorphometric parameters derived from the DEM. The study site chosen for this analysis is an abandoned agricultural field near the city of Taroudant, in the semi-arid southern part of Morocco. The site is characterized by aggressive rill and gully erosion and is - apart from sparsely scattered shrub cover - mainly featureless. An area of 5.7 ha, equipped with 30 high-precision ground control points (GCPs), was covered with an unmanned aerial vehicle (UAV) in two different heights (85 and 170 m). A selection of 160 images was used to generate several high-resolution DEMs (2 and 5 cm resolution) of the area using the fully automated SfM software AGISOFT Photoscan. For comparison purposes, a conventional photogrammetry-based workflow using the Leica Photogrammetry Suite was used to generate a DEM with a resolution of 5 cm (LPS DEM). The evaluation is done by comparison of the SfM DEM with the derived orthoimages and the LPS DEM. Parameters evaluated include the flow accumulation, the extracted thalweg networks, slope and exposition. Thus, the question asked is not "Is the height at this specific point accurate compared to a true reference height?", but rather "Does the surface runoff modelled from this DEM behave in the same way as it does in reality?". This means that the DEM will be validated on a functional basis, examining the accuracy of hydrological connectivity and networks. The results of this work may help in the establishment of the SfM technique in geoscience applications, and give an idea of the hydrologic accuracy and reliability of such DEMs.

  11. Uncertainty of SWAT model at different DEM resolutions in a large mountainous watershed.

    PubMed

    Zhang, Peipei; Liu, Ruimin; Bao, Yimeng; Wang, Jiawei; Yu, Wenwen; Shen, Zhenyao

    2014-04-15

    The objective of this study was to enhance understanding of the sensitivity of the SWAT model to the resolutions of Digital Elevation Models (DEMs) based on the analysis of multiple evaluation indicators. The Xiangxi River, a large tributary of Three Gorges Reservoir in China, was selected as the study area. A range of 17 DEM spatial resolutions, from 30 to 1000 m, was examined, and the annual and monthly model outputs based on each resolution were compared. The following results were obtained: (i) sediment yield was greatly affected by DEM resolution; (ii) the prediction of dissolved oxygen load was significantly affected by DEM resolutions coarser than 500 m; (iii) Total Nitrogen (TN) load was not greatly affected by the DEM resolution; (iv) Nitrate Nitrogen (NO?-N) and Total Phosphorus (TP) loads were slightly affected by the DEM resolution; and (v) flow and Ammonia Nitrogen (NH?-N) load were essentially unaffected by the DEM resolution. The flow and dissolved oxygen load decreased more significantly in the dry season than in the wet and normal seasons. Excluding flow and dissolved oxygen, the uncertainties of the other Hydrology/Non-point Source (H/NPS) pollution indicators were greater in the wet season than in the dry and normal seasons. Considering the temporal distribution uncertainties, the optimal DEM resolutions for flow was 30-200 m, for sediment and TP was 30-100 m, for dissolved oxygen and NO?-N was 30-300 m, for NH?-N was 30 to 70 m and for TN was 30-150 m. PMID:24509347

  12. Sterblichkeit: der paradoxe Kunstgriff des Lebens - Eine Betrachtung vor dem Hintergrund der modernen Biologie

    NASA Astrophysics Data System (ADS)

    Verbeek, Bernhard

    Leben gibt es auf der Erde seit fast 4 Mio. Jahren, trotz allen Katastrophen. Die Idee des Lebens scheint unsterblich. Der Tod aber offenbar auch. Jedes Lebewesen ist davon bedroht, ja für Menschen und andere "höhere“ Lebewesen ist er im Lebensprogramm eingebaut - todsicher. Diese Tatsache ist alles andere als selbstverständlich. Ist sie überhaupt kompatibel mit dem Prinzip der Evolution, nach dem der am besten Angepasste überlebt?

  13. An improved method to represent DEM uncertainty in glacial lake outburst flood propagation using stochastic simulations

    NASA Astrophysics Data System (ADS)

    Watson, Cameron S.; Carrivick, Jonathan; Quincey, Duncan

    2015-10-01

    Modelling glacial lake outburst floods (GLOFs) or 'jökulhlaups', necessarily involves the propagation of large and often stochastic uncertainties throughout the source to impact process chain. Since flood routing is primarily a function of underlying topography, communication of digital elevation model (DEM) uncertainty should accompany such modelling efforts. Here, a new stochastic first-pass assessment technique was evaluated against an existing GIS-based model and an existing 1D hydrodynamic model, using three DEMs with different spatial resolution. The analysis revealed the effect of DEM uncertainty and model choice on several flood parameters and on the prediction of socio-economic impacts. Our new model, which we call MC-LCP (Monte Carlo Least Cost Path) and which is distributed in the supplementary information, demonstrated enhanced 'stability' when compared to the two existing methods, and this 'stability' was independent of DEM choice. The MC-LCP model outputs an uncertainty continuum within its extent, from which relative socio-economic risk can be evaluated. In a comparison of all DEM and model combinations, the Shuttle Radar Topography Mission (SRTM) DEM exhibited fewer artefacts compared to those with the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), and were comparable to those with a finer resolution Advanced Land Observing Satellite Panchromatic Remote-sensing Instrument for Stereo Mapping (ALOS PRISM) derived DEM. Overall, we contend that the variability we find between flood routing model results suggests that consideration of DEM uncertainty and pre-processing methods is important when assessing flow routing and when evaluating potential socio-economic implications of a GLOF event. Incorporation of a stochastic variable provides an illustration of uncertainty that is important when modelling and communicating assessments of an inherently complex process.

  14. HELI-DEM portal for geo-processing services

    NASA Astrophysics Data System (ADS)

    Cannata, Massimiliano; Antonovic, Milan; Molinari, Monia

    2014-05-01

    HELI-DEM (Helvetia-Italy Digital Elevation Model) is a project developed in the framework of Italy/Switzerland Operational Programme for Trans-frontier Cooperation 2007-2013 whose major aim is to create a unified digital terrain model that includes the alpine and sub-alpine areas between Italy and Switzerland. The partners of the project are: Lombardy Region, Piedmont Region, Polytechnic of Milan, Polytechnic of Turin and Fondazione Politecnico from Italy; Institute of Earth Sciences (SUPSI) from Switzerland. The digital terrain model has been produced by integrating and validating the different elevation data available for the areas of interest, characterized by different reference frame, resolutions and accuracies: DHM at 25 m resolution from Swisstopo, DTM at 20 m resolution from Lombardy Region, DTM at 5 m resolution from Piedmont Region and DTM LiDAR PST-A at about 1 m resolution, that covers the main river bed areas and is produced by the Italian Ministry of the Environment. Further results of the project are: the generation of a unique Italian Swiss geoid with an accuracy of few centimeters (Gilardoni et al. 2012); the establishment of a GNSS permanent network, prototype of a transnational positioning service; the development of a geo-portal, entirely based on open source technologies and open standards, which provides the cross-border DTM and offers some capabilities of analysis and processing through the Internet. With this talk, the authors want to present the main steps of the project with a focus on the HELI-DEM geo-portal development carried out by the Institute of Earth Sciences, which is the access point to the DTM outputted from the project. The portal, accessible at http://geoservice.ist.supsi.ch/helidem, is a demonstration of open source technologies combined for providing access to geospatial functionalities to wide non GIS expert public. In fact, the system is entirely developed using only Open Standards and Free and Open Source Software (FOSS) both on the server side (services) and on the client side (interface). In addition to self developed code the system relies mainly on teh software GRASS 7 [1], ZOO-project [2], Geoserver [3] and OpenLayers [4] and the standards WMS [5], WCS [6] and WPS [7]. At the time of writing, the portal offers features like profiling, contour extraction, watershed delineation and analysis, derivatives calculation, data extraction, coordinate conversion but it is evolving and it is planned to extend to a series of environmental modeling that the IST developed in the past like dam break simulation, landslide run-out estimation and floods due to landslide impact in artificial basins. [1] Neteler M., Mitasova H., Open Source GIS: A GRASS GIS Approach. 3rd Ed. 406 pp, Springer, New York, 2008. [2] Fenoy G., Bozon N., Raghavan V., ZOO Project: The Open Wps Platform. Proceeding of 1st International Workshop on Pervasive Web Mapping, Geoprocessing and Services (WebMGS). Como, http://www.isprs.org/proceedings/XXXVIII/4-W13/ID_32.pdf, 26-27 agosto 2010. [3] Giannecchini S., Aime A., GeoServer, il server open source per la gestione interoperabile dei dati geospaziali. Atti 15a Conferenza Nazionale ASITA. Reggia di Colorno, 15-18 novembre 2011. [4] Perez A.S., OpenLayers Cookbook. Packt Publishing, 2012. ISBN 1849517843. [5] OGC, OpenGIS Web Map Server Implementation Specification, http://www.opengeospatial.org/standards/wms, 2006. [6] OGC, OGC WCS 2.0 Interface Standard - Core, http://portal.opengeospatial.org/files/?artifact_id=41437, 2010b. [7] OGC, OpenGIS Web Processing Service, http://portal.opengeospatial.org/files/?artifact_id=24151, 2007.

  15. Monitoring lava dome changes by means of differential DEMs from TanDEM-X interferometry: Examples from Merapi, Indonesia and Volcán de Colima, Mexico

    NASA Astrophysics Data System (ADS)

    Kubanek, J.; Westerhaus, M.; Heck, B.

    2013-12-01

    Estimating the amount of erupted material during a volcanic crisis is one of the major challenges in volcano research. One way to do this and to discriminate between juvenile and non-juvenile fraction is to assess topographic changes before and after an eruption while using area-wide 3D data. LiDAR or other airborne systems may be a good source, but the recording fails when clouds due to volcanic activity obstruct the sight. In addition, costs as well as logistics are high for local observatories. When dealing with dome-building volcanoes, acquiring the data gets further complicated. As the volcano dome can change rapidly in active phases, it is nearly impossible to collect data at the right time. However, when dealing with gross volume change estimates, at least two data sets - taken directly before and after the eruption - are essential. The innovative German Earth observation mission TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) is of great importance to overcome some of these problems. The two almost identical radar satellites TerraSAR-X and TanDEM-X fly in a close formation, thus recording images of the same place on the Earth surface at the same time (bistatic mode). As the radar signal penetrates clouds, digital elevation models (DEMs) of the area of investigation can be generated without problems even with cloud cover. A time series analysis of the differential DEMs therefore opens the possibility to assess volume changes at active lava domes. We choose Merapi in Indonesia and Volcán de Colima in Mexico as test sites. Both volcanoes reside in a state of long term effusive eruption, interrupted every few years by phases of dome destruction, generation of pyroclastic flows and deposition of volcanic material. The availability of extensive ground truth data for both test sites further enables to validate the spaceborne data and results. Here, we analyze lava dome changes due to the hazardous Merapi 2010 eruption. We show a series of DEMs derived by TanDEM-X interferometry taken before and after the eruption. Our results reveal that the eruption had led to a topographic change of up to 200 m in the summit area of Merapi. We further show the ability of the TanDEM-X data to observe much smaller topographic changes using Volcán de Colima as second test site. An explosion at the crater rim signaled the end of magma ascent in June 2011. The bistatic TanDEM-X data give important information on this explosion as we can observe topographic changes of up to 20 m and less in the summit area when comparing datasets taken before and after the event. We further analyzed datasets from the beginning of the year 2013 when Colima got active again after a dormant period. Our results indicate that repeated DEMs with great detail and good accuracy are obtainable, enabling a quantitative estimation of volume changes in the summit area of the volcano. As the TanDEM-X mission is an innovative mission, the present study serves as a test to employ data of a new satellite mission in volcano research. An error analysis of the DEMs to evaluate the volume quantifications was therefore also conducted.

  16. ArcGeomorphometry: A toolbox for geomorphometric characterisation of DEMs in the ArcGIS environment

    NASA Astrophysics Data System (ADS)

    Rigol-Sanchez, Juan P.; Stuart, Neil; Pulido-Bosch, Antonio

    2015-12-01

    A software tool is described for the extraction of geomorphometric land surface variables and features from Digital Elevation Models (DEMs). The ArcGeomorphometry Toolbox consists of a series of Python/Numpy processing functions, presented through an easy-to-use graphical menu for the widely used ArcGIS package. Although many GIS provide some operations for analysing DEMs, the methods are often only partially implemented and can be difficult to find and used effectively. Since the results of automated characterisation of landscapes from DEMs are influenced by the extent being considered, the resolution of the source DEM and the size of the kernel (analysis window) used for processing, we have developed a tool to allow GIS users to flexibly apply several multi-scale analysis methods to parameterise and classify a DEM into discrete land surface units. Users can control the threshold values for land surface classifications. The size of the processing kernel can be used to identify land surface features across a range of landscape scales. The pattern of land surface units from each attempt at classification is displayed immediately and can then be processed in the GIS alongside additional data that can assist with a visual assessment and comparison of a series of results. The functionality of the ArcGeomorphometry toolbox is described using an example DEM.

  17. P bordet ligger sex hrband som inte nuddar varandra. Ovanp dem ligger ett papper som delvis tcker dem (se bild). Man vet att tre av

    E-print Network

    delvis täcker dem (se bild). Man vet att tre av hårbanden är tunna, medan tre är tjocka och att banden är helt täckt: ett tunt eller ett tjockt? Och hur kan det se ut under pappret? Vill du ha fler sådana institutionen, Stockholms universitet: Sal 22, Hus 5, Kräftriket. Mer information och anmälan: www.math.su.se

  18. Crucial Points of Interferometric Processing for dem Generation Using High Resolution SAR Data

    NASA Astrophysics Data System (ADS)

    Sefercik, U. G.; Dana, I.

    2011-09-01

    Data collection for digital elevation model (DEM) generation can be carried out by two main methods in space-borne remote sensing such as stereoscopy using optical or radar satellite imagery (stereophotogrammetry, respectively radargrammetry) and interferometry based on interferometric synthetic aperture radar (InSAR) data. These techniques have advantages and disadvantages in comparison against each other. Especially filling the gaps which arise from the problem of cloud coverage in DEM generation by optical imagery, InSAR became operational in recent years and DEMs became the most demanded interferometric products. Essentially, in comparison, DEM generation from synthetic aperture radar (SAR) images is not a simple manner like generation from optical satellite imagery. Interferometric processing has several complicated steps for the production of a DEM. The quality of the data set and used software package come into prominence for the stability of the generated DEM. In the paper, the interferometric processing steps for DEM generation from InSAR data and the crucial threshold values are tried to be explained. For DEM generation, a part of Istanbul (historical peninsula and near surroundings) was selected as the test field because of data availability. The data sets of two different imaging modes (StripMap ~ 3 m resolution and High Resolution Spotlight ~ 1 m resolution) of TerraSAR-X have been used. At the implementation, besides the determination of crucial points at interferometric processing steps, to define the effect of computer software, DEM production have been performed using two different software packages in parallel and the products have been compared In the result section of the paper, besides the colorful visualizations of final products along with the height scales, accuracy evaluations have been performed for both DEMs with the help of a more accurate reference digital terrain model (DTM). This reference model has been achieved by large scale aerial photos. Normally, it has a 5 m original grid spacing, however it has been resampled at a spacing of 1 m towards the needs of the research.

  19. ALOS DEM quality assessment in a rugged topography, A Lebanese watershed as a case study

    NASA Astrophysics Data System (ADS)

    Abdallah, Chadi; El Hage, Mohamad; Termos, Samah; Abboud, Mohammad

    2014-05-01

    Deriving the morphometric descriptors of the Earth's surface from satellite images is a continuing application in remote sensing, which has been distinctly pushed with the increasing availability of DEMs at different scales, specifically those derived from high to very high-resolution stereoscopic and triscopic image data. The extraction of the morphometric descriptors is affected by the errors of the DEM. This study presents a procedure for assessing the quality of ALOS DEM in terms of position and morphometric indices. It involves evaluating the impact of the production parameters on the altimetric accuracy through checking height differences between Ground Control Points (GCP) and the corresponding DEM points, on the planimetric accuracy by comparing extracted drainage lines with topographic maps, and on the morphometric indices by comparing profiles extracted from the DEM with those measured on the field. A twenty set of triplet-stereo imagery from the PRISM instrument on the ALOS satellite has been processed to acquire a 5 m DEM covering the whole Lebanese territories. The Lebanese topography is characterized by its ruggedness with two parallel mountainous chains embedding a depression (The Bekaa Valley). The DEM was extracted via PCI Geomatica 2013. Each of the images required 15 GCPs and around 50 tie points. Field measurements was carried out using differential GPS (Trimble GeoXH6000, ProXRT receiver and the LaserACE 1000 Rangefinder) on Al Awali watershed (482 km2, about 5% of the Lebanese terrain). 3545 GPS points were collected at all ranges of elevation specifying the Lebanese terrain diversity, ranging from cliffy, to steep and gently undulating terrain along with narrow and wide flood plains and including predetermined profiles. Moreover, definite points such as road intersections and river beds were also measured in order to assess the extracted streams from the DEM. ArcGIS 10.1 was also utilized to extract the drainage network. Preliminary results showed that using Toutin's Model, enabling Wallis filter and specifying high DEM detail, along with restricting the holes filling option gave the best position accuracy and the least number of failure values. This is mainly due to the ruggedness of the studying area. Comparing GPS heights with the extract DEM showed a Minimum and a maximum error of (-11.9 m, 10.56 m), Mean error (1.32 m) and RMSE of (4.7 m). While extracting the drainage lines showed 80 to 90 % of coincidence of the upper water heads and an order of less than one pixel for the main river course and mountainous road intersection.

  20. Recent Release of the ASTER Global DEM Product

    NASA Astrophysics Data System (ADS)

    Behnke, J.; Hall, A.; Meyer, D.; Sohre, T.; Doescher, C.

    2009-12-01

    On June 29th, the ASTER Global Digital Elevation Model (DEM) release was announced to the public and to a very eager audience. ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) is an imaging instrument flying on Terra, a satellite launched in December 1999 as part of NASA's Earth Observing System (EOS). ASTER is a cooperative effort between NASA, Japan's Ministry of Economy, Trade and Industry (METI) and Japan's Earth Remote Sensing Data Analysis Center (ERSDAC). On June 21, NASA Headquarters along with colleagues in Japan (METI) signed a plan for distribution of this product. The global digital elevation model of Earth is available online to users everywhere at no cost from NASA's Land Processes Distributed Active Archive Center (DAAC) located at Sioux Falls, SD. The DAAC is a joint project of NASA and the USGS and is a key component of NASA's EOSDIS. The new ASTER GDEM was created from nearly 1.3 million individual stereo-pair images acquired by the Japanese Advanced Spaceborne Thermal Emission and Reflection Radiometer (Aster) instrument aboard NASA’s Terra satellite. The ASTER elevation model was jointly developed by NASA and METI under contract to Sensor Information Laboratory Corp., Tsukuba, Japan. On June 29, the NASA press release was picked up quickly by numerous news organizations and online sites. Response to the product was incredible! The news of the release of the product was carried on websites across the globe, this fueled a tremendous response from users. Here are a few interesting metrics about the release: - over 41,000 unique visitors to website in first week following release - top countries in order were: US (approx. 20%), Germany, U.K., Brazil, Austria, Canada, Spain, Switzerland, Japan - approximately 29,000 visitors came to the news page in the first week and about 11,000 of these users downloaded the actual press release - by the end of August, over 2 Million ASTER GDEM files had been downloaded from the Land Processes DAAC This presentation covers the issues associated with the release of this very popular product, including issues raised by many of our users.

  1. Acute environmental toxicity and persistence of DEM, a chemical agent simulant: Diethyl malonate. [Diethyl malonate

    SciTech Connect

    Cataldo, D.A.; Ligotke, M.W.; Harvey, S.D.; Fellows, R.J.; Li, Shu-mei W.; Van Voris, P.; Wentsel, R.S.

    1990-05-01

    The purpose of the following chemical simulant studies is to assess the potential acute environmental effects and persistence of diethyl malonate (DEM). Deposition velocities for DEM to soil surfaces ranged from 0.04 to 0.2 cm/sec. For foliar surfaces, deposition velocities ranged from 0.0002 cm/sec at low air concentrations to 0.05 cm/sec for high dose levels. The residence times or half-lives of DEM deposited to soils was 2 h for the fast component and 5 to 16 h for the residual material. DEM deposited to foliar surfaces also exhibited biphasic depuration. The half-life of the short residence time component ranged from 1 to 3 h, while the longer time component had half-times of 16 to 242 h. Volatilization and other depuration mechanisms reduce surface contaminant levels in both soils and foliage to less than 1% of initial dose within 96 h. DEM is not phytotoxic at foliar mass loading levels of less than 10 {mu}m/cm{sup 2}. However, severe damage is evident at mass loading levels in excess of 17 {mu}g/cm{sup 2}. Tall fescue and sagebrush were more affected than was short-needle pine, however, mass loading levels were markedly different. Regrowth of tall fescue indicated that the effects of DEM are residual, and growth rates are affected only at higher mass loadings through the second harvest. Results from in vitro testing of DEM indicated concentrations below 500 {mu}g/g dry soil generally did not negatively impact soil microbial activity. Short-term effects of DEM were more profound on soil dehydrogenase activity than on soil phosphatase activity. No enzyme inhibition or enhancement was observed after 28 days in incubation. Results of the earthworm bioassay indicate survival to be 86 and 66% at soil doses of 107 and 204 {mu}g DEM/cm{sup 2}, respectively. At higher dose level, activity or mobility was judged to be affected in over 50% of the individuals. 21 refs., 10 figs., 15 tabs.

  2. Numerische Verfahren fr die PET Diplomarbeit

    E-print Network

    Louis, Alfred K.

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 4.6.1 FOREX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 4.6.2 FORE.6.4 Zusammenhang zwischen FORE, FOREX und FORE-J . . . . . . 125 4.7 Vergleich der Algorithmen dieses Kapitels

  3. DEM Extraction from High-Resolution Stereoscopic Worldview 1 & 2 Imagery of Polar Outlet Glaciers

    NASA Astrophysics Data System (ADS)

    Porter, C. C.; Morin, P. J.; Howat, I. M.; Niebuhr, S.; Smith, B. E.

    2011-12-01

    There are few reliable digital elevation models (DEMs) in polar regions and most are of low resolution (on the order of 100's of meters to km) or of poor quality. Polar environments are changing rapidly and accurate DEMs are critical for correcting imagery, measuring glacier thickness changes and modeling ice flow and surface melt water drainage. Using in-track stereoscopic images from Worldview-1 and Worldview-2, we derived high-resolution DEMs for outlet glaciers and other areas of interest in Antarctica and the Arctic. We used ERDAS Imagine's LPS eATE (enhanced automated terrain extraction) algorithm to derive a dense point cloud of matches. The resulting point cloud is comparable in density to that obtained by LiDAR flown at 10,000 feet. Preliminary comparisons of our results to ground control points collected by field teams and airborne and satellite laser altimeters show 0.5 - 10 meter vertical error over glaciers and 2 - 10 meter error over ice-free terrain. The error is primarily due to approximations in the sensor model and is consistent across the DEM. Our results indicate that refinements in the sensor model and point matching algorithm will improve accuracy. Given the increasing interest in glacier change detection around the globe, DEMs extracted from frequent satellite stereo pairs can be used to monitor and quantify changes in both movement and volume.

  4. Perspective - synthetic DEMs: a vital underpinning for the quantitative future of landform analysis?

    NASA Astrophysics Data System (ADS)

    Hillier, J. K.; Sofia, G.; Conway, S. J.

    2015-07-01

    Physical processes, including anthropogenic feedbacks, sculpt planetary surfaces (e.g., Earth's). A fundamental tenet of Geomorphology is that the shapes created, when combined with other measurements, can be used to understand those processes. Artificial or synthetic Digital Elevation Models (DEMs) might be vital in progressing further with this endeavour. Morphological data, including metrics and mapping (manual and automated) are a key resource, but at present their quality is typically weakly constrained (e.g., by mapper inter-comparison). In addition to examining inaccuracies caused by noise, relatively rare examples illustrate how synthetic DEMs containing a priori known, idealised morphologies can be used perform "synthetic tests" to make strong "absolute" statements about landform detection and quantification; e.g., 84 % of valley heads in the real landscape are identified correctly. From our perspective, it is vital to verify such statistics as ultimately they link physics-driven models of processes to morphological observations, allowing quantitative hypotheses to be formulated and tested. Synthetic DEMs built by directly using governing equations that encapsulate processes are another key part of forming this link. Thus, this note introduces synthetic tests and DEMs, then it outlines a typology of synthetic DEMs along with their benefits, challenges and future potential to provide constraints and insights. The aim is to discuss how we best proceed with uncertainty-aware landscape analysis to examine physical processes.

  5. Identifying LiDAR sample uncertainty on terrain features from DEM simulation

    NASA Astrophysics Data System (ADS)

    Chu, Hone-Jay; Chen, Ruey-An; Tseng, Yi-Hsing; Wang, Cheng-Kai

    2014-01-01

    Light detection and ranging (LiDAR) is an effective technology to detect highly dense-point elevation data from terrain surfaces. The density of LiDAR data points significantly affects the level of detail of a high-resolution digital elevation model (DEM). In this study, the conditioned Latin hypercube sampling (cLHS) and simple random sampling (SRS) methods select sufficient LiDAR samples, and sequential Gaussian simulation (SGS) generates multiple DEM realizations that are a set of simulated DEM maps subject to a specified mean, variance, and spatial structure of measured data. Based on DEM realizations, the uncertainty of a spatial feature with a specified elevation is determined. The results suggest that LiDAR sampling patterns, including the size and configuration, affect the spatial distribution of the feature uncertainty, especially when the sample size is small. The accuracy of a DEM is dependent on the choice of sampling techniques for low sampling density data. Unlike random sampling, the cLHS method replicates the distribution of spatial elevation patterns in small sample sizes. Hence, the integrated method can assess the uncertainty of spatial features efficiently in geomorphic monitoring and management.

  6. A beginner's guide to stereo-derived DEM production and analysis using ISIS, ASP, and ArcMap

    E-print Network

    Rathbun, Julie A.

    A beginner's guide to stereo-derived DEM production and analysis using ISIS, ASP, and ArcMap v. 1 ............................................................................................................................5 2. Processing the images with ISIS

  7. DEM analyses of shear behaviour of rock joints by a novel bond contact model

    NASA Astrophysics Data System (ADS)

    Jiang, M. J.; Liu, J.; Sun, C.; Chen, H.

    2015-09-01

    The failure of rock joints is one of the potential causes for the local and general rock instability, which may trigger devastating geohazards such as landslide. In this paper, the Distinct Element Method (DEM) featured by a novel bond contact model was utilized to simulate shear behaviour of centre/non-coplanar rock joints. The DEM results show that the complete shear behaviour of jointed rock includes four stages: elastic shearing phase, crack propagation, the failure of rock bridges and the through-going discontinuity. The peak shear strength of centre joint increases as the joint connectivity rate decreases. For intermittent noncoplanar rock joints, as the inclination of the rock joints increases, its shear capacity decreases when the inclination angle is negative while increase when positive. Comparison with the experimental results proves the capability of this DEM model in capturing the mechanical properties of the jointed rocks.

  8. Flow Dynamics of green sand in the DISAMATIC moulding process using Discrete element method (DEM)

    NASA Astrophysics Data System (ADS)

    Hovad, E.; Larsen, P.; Walther, J. H.; Thorborg, J.; Hattel, J. H.

    2015-06-01

    The DISAMATIC casting process production of sand moulds is simulated with DEM (discrete element method). The main purpose is to simulate the dynamics of the flow of green sand, during the production of the sand mould with DEM. The sand shot is simulated, which is the first stage of the DISAMATIC casting process. Depending on the actual casting geometry the mould can be geometrically quite complex involving e.g. shadowing effects and this is directly reflected in the sand flow during the moulding process. In the present work a mould chamber with “ribs” at the walls is chosen as a baseline geometry to emulate some of these important conditions found in the real moulding process. The sand flow is simulated with the DEM and compared with corresponding video footages from the interior of the chamber during the moulding process. The effect of the rolling resistance and the static friction coefficient is analysed and discussed in relation to the experimental findings.

  9. CFD-DEM Simulations of Current-Induced Dune Formation and Morphological Evolution

    E-print Network

    Sun, Rui

    2015-01-01

    Understanding the fundamental mechanisms of sediment transport, particularly those during the formation and evolution of bedforms, is of critical scientific importance and has engineering relevance. Traditional approaches of sediment transport simulations heavily rely on empirical models, which are not able to capture the physics-rich, regime-dependent behaviors of the process. With the increase of available computational resources in the past decade, CFD-DEM (computational fluid dynamics-discrete element method) has emerged as a viable high-fidelity method for the study of sediment transport. However, a comprehensive, quantitative study of the generation and migration of different sediment bed patterns using CFD-DEM is still lacking. In this work, current-induced sediment transport problems in a wide range of regimes are simulated, including 'flat bed in motion', `small dune', `vortex dune' and suspended transport. Simulations are performed by using SediFoam, an open-source, massively parallel CFD-DEM solver...

  10. FEM × DEM modelling of cohesive granular materials: Numerical homogenisation and multi-scale simulations

    NASA Astrophysics Data System (ADS)

    Nguyen, Trung; Combe, Gaël; Caillerie, Denis; Desrues, Jacques

    2014-10-01

    The article presents a multi-scale modelling approach of cohesive granular materials, its numerical implementation and its results. At microscopic level, Discrete Element Method (DEM) is used to model dense grains packing. At the macroscopic level, the numerical solution is obtained by a Finite Element Method (FEM). In order to bridge the micro- and macro-scales, the concept of Representative Elementary Volume (REV) is applied, in which the average REV stress and the consistent tangent operators are obtained in each macroscopic integration point as the results of DEM's simulation. In this way, the numerical constitutive law is determined through the detailed modelling of the microstructure, taking into account the nature of granular materials. We first elaborate the principle of the computation homogenisation (FEM × DEM), then demonstrate the features of our multiscale computation in terms of a biaxial compression test. Macroscopic strain location is observed and discussed.

  11. Quality assessment of Digital Elevation Model (DEM) in view of the Altiplano hydrological modeling

    NASA Astrophysics Data System (ADS)

    Satgé, F.; Arsen, A.; Bonnet, M.; Timouk, F.; Calmant, S.; Pilco, R.; Molina, J.; Lavado, W.; Crétaux, J.; HASM

    2013-05-01

    Topography is crucial data input for hydrological modeling but in many regions of the world, the only way to characterize topography is the use of satellite-based Digital Elevation Models (DEM). In some regions, the quality of these DEMs remains poor and induces modeling errors that may or not be compensated by model parameters tuning. In such regions, the evaluation of these data uncertainties is an important step in the modeling procedure. In this study, which focuses on the Altiplano region, we present the evaluation of the two freely available DEM. The shuttle radar topographic mission (SRTM), a product of the National Aeronautics and Space Administration (NASA) and the Advanced Space Born Thermal Emission and Reflection Global Digital Elevation Map (ASTER GDEM), data provided by the Ministry of Economy, Trade and Industry of Japan (MESI) in collaboration with the NASA, are widely used. While the first represents a resolution of 3 arc seconds (90m) the latter is 1 arc second (30m). In order to select the most reliable DEM, we compared the DEM elevation with high qualities control points elevation. Because of its large spatial coverture (track spaced of 30 km with a measure of each 172 m) and its high vertical accuracy which is less than 15 cm in good weather conditions, the Geoscience Laser Altimeter System (GLAS) on board on the Ice, Cloud and Land elevation Satellite of NASA (ICESat) represent the better solution to establish a high quality elevation database. After a quality check, more than 150 000 ICESat/GLAS measurements are suitable in terms of accuracy for the Altiplano watershed. This data base has been used to evaluate the vertical accuracy for each DEM. Regarding to the full spatial coverture; the comparison has been done for both, all kind of land coverture, range altitude and mean slope.

  12. Assessment of Digital Elevation Model (DEM) aggregation methods for hydrological modeling: Lake Chad basin, Africa

    NASA Astrophysics Data System (ADS)

    Le Coz, Mathieu; Delclaux, François; Genthon, Pierre; Favreau, Guillaume

    2009-08-01

    Digital Elevation Models (DEMs) are used to compute the hydro-geomorphological variables required by distributed hydrological models. However, the resolution of the most precise DEMs is too fine to run these models over regional watersheds. DEMs therefore need to be aggregated to coarser resolutions, affecting both the representation of the land surface and the hydrological simulations. In the present paper, six algorithms (mean, median, mode, nearest neighbour, maximum and minimum) are used to aggregate the Shuttle Radar Topography Mission (SRTM) DEM from 3? (90 m) to 5' (10 km) in order to simulate the water balance of the Lake Chad basin (2.5 Mkm 2). Each of these methods is assessed with respect to selected hydro-geomorphological properties that influence Terrestrial Hydrology Model with Biogeochemistry (THMB) simulations, namely the drainage network, the Lake Chad bottom topography and the floodplain extent. The results show that mean and median methods produce a smoother representation of the topography. This smoothing involves the removing of the depressions governing the floodplain dynamics (floodplain area<5000 km 2) but it eliminates the spikes and wells responsible for deviations regarding the drainage network. By contrast, using other aggregation methods, a rougher relief representation enables the simulation of a higher floodplain area (>14,000 km 2 with the maximum or nearest neighbour) but results in anomalies concerning the drainage network. An aggregation procedure based on a variographic analysis of the SRTM data is therefore suggested. This consists of preliminary filtering of the 3? DEM in order to smooth spikes and wells, then resampling to 5' via the nearest neighbour method so as to preserve the representation of depressions. With the resulting DEM, the drainage network, the Lake Chad bathymetric curves and the simulated floodplain hydrology are consistent with the observations (3% underestimation for simulated evaporation volumes).

  13. TanDEM-X: A radar interferometer with two formation-flying satellites

    NASA Astrophysics Data System (ADS)

    Krieger, Gerhard; Zink, Manfred; Bachmann, Markus; Bräutigam, Benjamin; Schulze, Daniel; Martone, Michele; Rizzoli, Paola; Steinbrecher, Ulrich; Walter Antony, John; De Zan, Francesco; Hajnsek, Irena; Papathanassiou, Kostas; Kugler, Florian; Rodriguez Cassola, Marc; Younis, Marwan; Baumgartner, Stefan; López-Dekker, Paco; Prats, Pau; Moreira, Alberto

    2013-08-01

    TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurements) is an innovative formation-flying radar mission that opens a new era in spaceborne radar remote sensing. The primary objective is the acquisition of a global digital elevation model (DEM) with unprecedented accuracy (12 m horizontal resolution and 2 m relative height accuracy). This goal is achieved by extending the TerraSAR-X synthetic aperture radar (SAR) mission by a second, TerraSAR-X like satellite (TDX) flying in close formation with TerraSAR-X (TSX). Both satellites form together a large single-pass SAR interferometer with the opportunity for flexible baseline selection. This enables the acquisition of highly accurate cross-track interferograms without the inherent accuracy limitations imposed by repeat-pass interferometry due to temporal decorrelation and atmospheric disturbances. Besides the primary goal of the mission, several secondary mission objectives based on along-track interferometry as well as new bistatic and multistatic SAR techniques have been defined, representing an important and innovative asset of the TanDEM-X mission. TanDEM-X is implemented in the framework of a public-private partnership between the German Aerospace Center (DLR) and EADS Astrium GmbH. The TanDEM-X satellite was successfully launched in June 2010 and the mission started its operational data acquisition in December 2010. This paper provides an overview of the TanDEM-X mission and summarizes its actual status and performance. Furthermore, results from several scientific radar experiments are presented that show the great potential of future formation-flying interferometric SAR missions to serve novel remote sensing applications.

  14. Perspective - Synthetic DEMs: A vital underpinning for the quantitative future of landform analysis?

    NASA Astrophysics Data System (ADS)

    Hillier, John K.; Sofia, Giulia; Conway, Susan

    2015-04-01

    Physical processes, including anthropogenic feedbacks, sculpt planetary surfaces (e.g., Earth's). A fundamental tenet of Geomorphology is that the shapes created, when combined with other measurements, can be used to understand those processes. Morphological data, including metrics and mapping (manual and automated), are a key resource in this endeavour. However, how good are these data that analyses rely on? Artificial or synthetic DEMs are widely used to examine the distortions of 'noise' (e.g., on topographic parameters), but only rarely to make strong 'absolute' statements about landform detection and quantification; e.g., 84% of the river channels in the real landscape are found, or 47% of all actual drumlins H > 3 m are mapped. In theory synthetic DEMs a priori containing known, idealised components can give such absolute conclusions regarding effectiveness if they can be constructed so as to represent well the actual landscapes. So, do we need good realistic synthetic DEMs, how can we best construct them, and what for? From our perspective, they are vital to verify the statistics that will link physics-driven models of processes to morphological observations, allowing quantitative hypotheses to be formulated and tested. We will outline current approaches, and some speculations about the future, but we are seeking a discussion on how best to construct realistic synthetic DEMs and proceed with uncertainty-aware landscape analysis to examine physical processes.

  15. Tau auf dem Bei Alzheimer-Forschung denkt man nicht unbedingt an Teilchenbeschleuniger. Das Deutsche

    E-print Network

    Falge, Eva

    Tau auf dem Gedächtnis Bei Alzheimer-Forschung denkt man nicht unbedingt an Teilchenbeschleuniger Querschnitts durch ein Alzheimer- (links) und ein gesundes Gehirn (rechts). Der Verlust an Nervenzellen lässt die beiden Wissenschaftler, die schon viel Licht ins Dunkel der Entstehung von Morbus Alzheimer

  16. Tau auf dem Bei Alzheimer-Forschung denkt man nicht unbedingt an Teilchenbeschleuniger. Das Deutsche

    E-print Network

    Falge, Eva

    Tau auf dem Gedächtnis Bei Alzheimer-Forschung denkt man nicht unbedingt an Teilchenbeschleuniger Querschnitts durch ein Alzheimer- (links) und ein gesundes Gehirn (rechts). Der Verlust an Nervenzellen lässt Alzheimer gebracht haben, ,,die ultima- tive Taschenlampe". Zu den Mandelkows? Der Pförtner greift wortlos

  17. Representative hillslope methods for applying the WEPP model with DEMs and GIS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modeling procedures called the Hillslope methods were developed that use geographical information systems (GIS) and digital elevation models (DEMs) to assess water erosion in small watersheds with the Water Erosion Prediction Project (WEPP) model. The Hillslope methods are automated procedures to d...

  18. A problem-oriented approach for DEM data management and manipulation

    NASA Astrophysics Data System (ADS)

    Huang, Fengru; Fang, Yu; Chen, Bin

    2009-10-01

    For the last decades, GIS software technologies have made tremendous development and applied to many special fields when their targets are relevant to geographical locations. But the basis of cartographic mapping of GIS is a restriction for more development in GIS data modelling, storage and manipulation. Recently, much attention is being paid on ORDBMS(Object Relational Database Management System) to represent and manage GIS Data. New approaches have earned acceptance in many research communities and several proposals have emerged in commercial software for solving the management and manipulation on GIS vector data. Though the storage and management of field-based model data(e.g. raster, DEM, TIN) have got less achievement and people still use files and procedural ways to manipulation field-based GIS data in common applications. In this paper a new structure model using ORDBMS technology for field-based data's storage and management was proposed on the basis of full discussion on several GIS data management technologies, then a problem-oriented approach for DEM data management and manipulation was designed and implemented through open source software systems PostgreSQL and Python language. Experimental examples of different DEM data souces were stored, managed and used by using the extended spatial database system. The experiments illustrated that this solution would be a useful supplement to spatial database and it provided an effective way to DEM data management and analysis, and support the interoperability between vector data and field data.

  19. A problem-oriented approach for DEM data management and manipulation

    NASA Astrophysics Data System (ADS)

    Huang, Fengru; Fang, Yu; Chen, Bin

    2008-10-01

    For the last decades, GIS software technologies have made tremendous development and applied to many special fields when their targets are relevant to geographical locations. But the basis of cartographic mapping of GIS is a restriction for more development in GIS data modelling, storage and manipulation. Recently, much attention is being paid on ORDBMS(Object Relational Database Management System) to represent and manage GIS Data. New approaches have earned acceptance in many research communities and several proposals have emerged in commercial software for solving the management and manipulation on GIS vector data. Though the storage and management of field-based model data(e.g. raster, DEM, TIN) have got less achievement and people still use files and procedural ways to manipulation field-based GIS data in common applications. In this paper a new structure model using ORDBMS technology for field-based data's storage and management was proposed on the basis of full discussion on several GIS data management technologies, then a problem-oriented approach for DEM data management and manipulation was designed and implemented through open source software systems PostgreSQL and Python language. Experimental examples of different DEM data souces were stored, managed and used by using the extended spatial database system. The experiments illustrated that this solution would be a useful supplement to spatial database and it provided an effective way to DEM data management and analysis, and support the interoperability between vector data and field data.

  20. In greren Lettern als der Titel prangt einer der beiden Autoren auf dem Cover

    E-print Network

    Falge, Eva

    In größeren Lettern als der Titel prangt einer der beiden Autoren auf dem Cover: Stephen Hawking letzten Schluss vorstellen, ,,42" oder der große Flop Stephen Hawking, Leonard Mlodinow, Der große Entwurf jenen, die es als Bestsellerauto- ren ganz oben in die Sachbuchcharts ge- schafft haben. Hawkings im

  1. Discrete element modelling (DEM) input parameters: understanding their impact on model predictions using statistical analysis

    NASA Astrophysics Data System (ADS)

    Yan, Z.; Wilkinson, S. K.; Stitt, E. H.; Marigo, M.

    2015-09-01

    Selection or calibration of particle property input parameters is one of the key problematic aspects for the implementation of the discrete element method (DEM). In the current study, a parametric multi-level sensitivity method is employed to understand the impact of the DEM input particle properties on the bulk responses for a given simple system: discharge of particles from a flat bottom cylindrical container onto a plate. In this case study, particle properties, such as Young's modulus, friction parameters and coefficient of restitution were systematically changed in order to assess their effect on material repose angles and particle flow rate (FR). It was shown that inter-particle static friction plays a primary role in determining both final angle of repose and FR, followed by the role of inter-particle rolling friction coefficient. The particle restitution coefficient and Young's modulus were found to have insignificant impacts and were strongly cross correlated. The proposed approach provides a systematic method that can be used to show the importance of specific DEM input parameters for a given system and then potentially facilitates their selection or calibration. It is concluded that shortening the process for input parameters selection and calibration can help in the implementation of DEM.

  2. Reconstructing Stellar DEMs from X-ray Spectra CHASC (California-Harvard AstroStatistics Collaboration)

    E-print Network

    Wolfe, Patrick J.

    a redistribution of the atomic emissivities across temperature, weighted by the DEM: #21; j = N T X i=1 #3; ji Æ for incorporating atomic data errors into the calculations. Some notable features of our algorithm are: { To #12;t information such as atomic line se- quences, known atomic data errors, systematic e#11;ects due to calibration

  3. aus dem Jahrbuch der Max-Planck-Gesellschaft from the Yearbook of the Max Planck Society

    E-print Network

    Leseproben aus dem Jahrbuch der Max-Planck-Gesellschaft Extracts from the Yearbook of the Max.mpg.de/166008/jahrbuecher The Yearbook of the Max Planck Society serves the purpose of scientific reporting of contributions from the Yearbook is presented below in the form of synopses. They are available on the internet

  4. Von Charles Darwin zu Oswald Heer (1809-1883), dem ersten Direktor des

    E-print Network

    Zürich, Universität

    Von Charles Darwin zu Oswald Heer (1809-1883), dem ersten Direktor des Botanischen Gartens Zürich Dieses Jahr wird Charles Darwin weltweit geehrt. Wir feiern den 200. Geburtstag eines grossen und in der Bibliothek der Botanischen Institute Einblicke in die Welt von ,,Charles Darwin als

  5. Mit dem Namen Charles Darwin verbinden sich immer auch die nach ihm benannten

    E-print Network

    Falge, Eva

    Mit dem Namen Charles Darwin verbinden sich immer auch die nach ihm benannten Darwinfinken auf den entwickelten weitgehend übereinstimmt. Seitdem Charles Darwin seine Überle- gungen nach langen Jahren des wissenschaftshistori- schen Bedeutung von Charles Darwin. Er beschreibt, wie Darwin ein neues Verständ- nis von der

  6. How Can the TanDEM-X Digital Elevation Model Support Terrestrial Impact Crater Studies?

    NASA Astrophysics Data System (ADS)

    Gottwald, M.; Fritz, T.; Breit, H.; Schaettler, B.; Harris, A.

    2015-09-01

    The German Aerospace Center operated the X-band radar satellites TerraSAR-X and TanDEM-X as a single-pass SAR interferometer. Data acquisition occurred over the entire land surface for the generation of a very high quality digital elevation model.

  7. A simplified DEM-CFD approach for pebble bed reactor simulations

    SciTech Connect

    Li, Y.; Ji, W.

    2012-07-01

    In pebble bed reactors (PBR's), the pebble flow and the coolant flow are coupled with each other through coolant-pebble interactions. Approaches with different fidelities have been proposed to simulate similar phenomena. Coupled Discrete Element Method-Computational Fluid Dynamics (DEM-CFD) approaches are widely studied and applied in these problems due to its good balance between efficiency and accuracy. In this work, based on the symmetry of the PBR geometry, a simplified 3D-DEM/2D-CFD approach is proposed to speed up the DEM-CFD simulation without significant loss of accuracy. Pebble flow is simulated by a full 3-D DEM, while the coolant flow field is calculated with a 2-D CFD simulation by averaging variables along the annular direction in the cylindrical geometry. Results show that this simplification can greatly enhance the efficiency for cylindrical core, which enables further inclusion of other physics such as thermal and neutronic effect in the multi-physics simulations for PBR's. (authors)

  8. Spuren von Massenbewegungen auf dem Grund des Vierwaldstttersees bei Weggis: Die Ereignisse von 1601 und 1795

    E-print Network

    Gilli, Adrian

    83 Spuren von Massenbewegungen auf dem Grund des Vierwaldstättersees bei Weggis: Die Ereignisse von- gangenheit wiederholt von subaquatischen Massenbewegungen erfasst (z. B. Schnell- mann et al. 2006). Die zwei jüngsten Gross- ereignisse sind die von einem Erdbeben in Unterwalden (MW ~ 6.2) ausgelöste subaqua- tische

  9. Von und ber Albert Einstein aus dem Bibliotheksbestand des kiz der Universitt Ulm

    E-print Network

    Ulm, Universität

    Von und über Albert Einstein aus dem Bibliotheksbestand des kiz der Universität Ulm Titel Autor Synthese Madary, Carl Alberti 1921 J96: B 3500/1921 M Akademie-Vorträge Einstein, Albert Treder, Hans- Jürgen Akademie-Verl. 1979 BZ: p QC 3/1979 E Ex.2 W: p QC 3/1979 E Albert Einstein: sein Einfluß auf

  10. 04.03.2010Prof. Dr. H. Ingensand Geodtische Messtechnik und Ingenieurgeodsie Innenraumpositionierung mit dem

    E-print Network

    Innenraumpositionierung mit dem Cricket-System (Indoor Positioning using Crickets) Rainer Mautz Freitag, 05. März 2010, 8 Latency Introduction in Wireless Positioning #12;· Global System for Mobile Communication (GSM) can des Cricket Systems -50 0 50 100 -50 0 50 -50 0 50 Z 01 Clustersize: 5 nodes 07 06 04 08

  11. RESEARCH/REVIEW ARTICLE A new DEM of the Austfonna ice cap by combining differential

    E-print Network

    Kääb, Andreas

    interferometry with ICESat laser altimetry Geir Moholdt & Andreas Ka¨a¨b Department of Geosciences, University with recent elevation data. The new and freely available DEM is constructed purely from spaceborne remote sensing data using differential SAR interferometry (DInSAR) in combination with ICESat laser altimetry

  12. North York (Yonge Street) building outlines with heights, clutter data, DEM, contours and places

    E-print Network

    Buildings Buildings > 50 13 Industrial area 14 Airstrip 15 River 16 Coast 17Title: North York (Yonge Street) building outlines with heights, clutter data, DEM, contours: 2010 Coverage Date(s): August 2009 Updates: N/A Abstract: - 3D Building Outlines in the City of Toronto

  13. Downtown Toronto building outlines with heights, clutter data, DEM, contours and places

    E-print Network

    Buildings Buildings > 50 13 Industrial area 14 Airstrip 15 River 16 Coast 17 Agriculture 18 StadiumTitle: Downtown Toronto building outlines with heights, clutter data, DEM, contours and places Data Date(s): August 2009 Updates: N/A Abstract: - 3D Building Outlines in the City of Toronto core

  14. The effect of DEM resolution on slope estimation and sediment predictions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Moderate resolution (30 m) digital elevation models (DEMs) are normally used to estimate slope for the parameterization of non-point source process-based water quality models. These models, such as the Soil and Water Assessment Tool (SWAT), utilize the Modified Universal Soil Loss Equation (MUSLE) ...

  15. Warum Astrologie nicht funktionieren kann

    E-print Network

    Freistetter, Florian

    2011-01-01

    There exists many different versions of astrology that are different from each other and sometimes even in conflict with each other. But the basis of every astrological system is the assumption of a connection between the motion of celestial bodies and the fate of man. An analysis of the methods of astrology shows that - regardless of which special system is used - there exists no consistent basis that allows to deduce general and verifiable rules. An astrological analysis is therefore always arbitrary and meaningless. Astrology does not work. ----- Astrologie existiert in vielen verschiedenen Versionen die sich oft deutliche voneinander unterscheiden und sogar widersprechen. Allen gemeinsam ist aber die grundlegende Annahme eines Zusammenhangs zwischen der Bewegung der Himmelsk\\"orper und dem Schicksal der Menschen. Eine Analyse der astrologischen Methodik zeigt, dass sie - egal in welcher konkreten Auspr\\"agung - \\"uber keine in sich schl\\"ussige Grundlage verf\\"ugt, anhand der sich allgemeing\\"ultige und \\...

  16. Inter-agency comparison of TanDEM-X baseline solutions

    NASA Astrophysics Data System (ADS)

    Jäggi, A.; Montenbruck, O.; Moon, Y.; Wermuth, M.; König, R.; Michalak, G.; Bock, H.; Bodenmann, D.

    2012-07-01

    TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) is the first Synthetic Aperture Radar (SAR) mission using close formation flying for bistatic SAR interferometry. The primary goal of the mission is to generate a global digital elevation model (DEM) with 2 m height precision and 10 m ground resolution from the configurable SAR interferometer with space baselines of a few hundred meters. As a key mission requirement for the interferometric SAR processing, the relative position, or baseline vector, of the two satellites must be determined with an accuracy of 1 mm (1D RMS) from GPS measurements collected by the onboard receivers. The operational baseline products for the TanDEM-X mission are routinely generated by the German Research Center for Geosciences (GFZ) and the German Space Operations Center (DLR/GSOC) using different software packages (EPOS/BSW, GHOST) and analysis strategies. For a further independent performance assessment, TanDEM-X baseline solutions are generated at the Astronomical Institute of the University of Bern (AIUB) on a best effort basis using the Bernese Software (BSW). Dual-frequency baseline solutions are compared for a 1-month test period in January 2011. Differences of reduced-dynamic baseline solutions exhibit a representative standard deviation (STD) of 1 mm outside maneuver periods, while biases are below 1 mm in all directions. The achieved baseline determination performance is close to the mission specification, but independent SAR calibration data takes acquired over areas with a well known DEM from previous missions will be required to fully meet the 1 mm 1D RMS target. Besides the operational solutions, single-frequency baseline solutions are tested. They benefit from a more robust ambiguity fixing and show a slightly better agreement of below 1 mm STD, but are potentially affected by errors caused by an incomplete compensation of differential ionospheric path delays.

  17. Validation of DEMs Derived from High Resolution SAR Data: a Case Study on Barcelona

    NASA Astrophysics Data System (ADS)

    Sefercik, U. G.; Schunert, A.; Soergel, U.; Watanabe, K.

    2012-07-01

    In recent years, Synthetic Aperture Radar (SAR) data have been widely used for scientific applications and several SAR missions were realized. The active sensor principle and the signal wavelength in the order of centimeters provide all-day and all-weather capabilities, respectively. The modern German TerraSAR-X (TSX) satellite provides high spatial resolution down to one meter. Based on such data SAR Interferometry may yield high quality digital surface models (DSMs), which includes points located on 3d objects such as vegetation, forest, and elevated man-made structures. By removing these points, digital elevation model (DEM) representing the bare ground of Earth is obtained. The primary objective of this paper is the validation of DEMs obtained from TSX SAR data covering Barcelona area, Spain, in the framework of a scientific project conducted by ISPRS Working Group VII/2 "SAR Interferometry" that aims the evaluation of DEM derived from data of modern SAR satellite sensors. Towards this purpose, a DSM was generated with 10 m grid spacing using TSX StripMap mode SAR data and converted to a DEM by filtering. The accuracy results have been presented referring the comparison with a more accurate (10 cm-1 m) digital terrain model (DTM) derived from large scale photogrammetry. The results showed that the TSX DEM is quite coherent with the topography and the accuracy is in between ±8-10 m. As another application, the persistent scatterer interferometry (PSI) was conducted using TSX data and the outcomes were compared with a 3d city model available in Google Earth, which is known to be very precise because it is based on LIDAR data. The results showed that PSI outcomes are quite coherent with reference data and the RMSZ of differences is around 2.5 m.

  18. Fusion of high-resolution DEMs derived from COSMO-SkyMed and TerraSAR-X InSAR datasets

    NASA Astrophysics Data System (ADS)

    Jiang, Houjun; Zhang, Lu; Wang, Yong; Liao, Mingsheng

    2014-06-01

    Voids caused by shadow, layover, and decorrelation usually occur in digital elevation models (DEMs) of mountainous areas that are derived from interferometric synthetic aperture radar (InSAR) datasets. The presence of voids degrades the quality and usability of the DEMs. Thus, void removal is considered as an integral part of the DEM production using InSAR data. The fusion of multiple DEMs has been widely recognized as a promising way for the void removal. Because the vertical accuracy of multiple DEMs can be different, the selection of optimum weights becomes a key problem in the fusion and is studied in this article. As a showcase, two high-resolution InSAR DEMs near Mt. Qilian in northwest China are created and then merged. The two pairs of InSAR data were acquired by TerraSAR-X from an ascending orbit and COSMO-SkyMed from a descending orbit. A maximum likelihood fusion scheme with the weights optimally determined by the height of ambiguity and the variance of phase noise is adopted to syncretize the two DEMs in our study. The fused DEM has a fine spatial resolution of 10 m and depicts the landform of the study area well. The percentage of void cells in the fused DEM is only 0.13 %, while 6.9 and 5.7 % of the cells in the COSMO-SkyMed DEM and the TerraSAR-X DEM are originally voids. Using the ICESat/GLAS elevation data and the Chinese national DEM of scale 1:50,000 as references, we evaluate vertical accuracy levels of the fused DEM as well as the original InSAR DEMs. The results show that substantial improvements could be achieved by DEM fusion after atmospheric phase screen removal. The quality of fused DEM can even meet the high-resolution terrain information (HRTI) standard.

  19. Testing DEM-based atmospheric corrections to SAR interferograms over the Los Angeles basin

    NASA Astrophysics Data System (ADS)

    Jin, L.; Funning, G. J.; Floyd, M. A.

    2009-12-01

    Atmospheric water vapor delay is the major source of noise in SAR interferograms. It is considered a prime disadvantage of high-precision InSAR technology. Without the atmospheric delay being corrected, it is hard to see any slow surface movements of the ground, e.g. fault creep; and it is impossible to validate Permanent Scatters InSAR method either, which assumes that water vapor can be estimated and removed by considering time series of interferograms. As long as the water vapor delay is estimated or measured, not only can we solve the previous two problems, but also reduce the errors in geodetic measurements, and improve the accuracy in generating Digital Elevation Models (DEMs) with ERS-1/2 tandem data. In order to reduce water vapor delay, there are some possible solutions using different data sets, including GPS, MODIS, and MERIS etc. This project is a method based on DEMs. It intends to find the relationship between topography and atmospheric water vapor delay in SAR interferograms so the water vapor signals can be reduced in interferograms. It is assumed that the atmospheric water vapor delay is linearly related to the topography over a certain distance. For example, the low phase delay appears over the places where the elevation is high; or low elevation leads to high phase delay. We tested 17 interferograms over the LA basin -- 5 from the ERS-1/2 tandem mission between 1995 and 1996; 12 from EnviSAT between 2005 and 2007 with the time spans from 35 days to 8 months. The basic idea was to divide each interferogram and DEM into a series of small windows. Then the coefficients of the relationship between the phase and the corresponding elevation in each same window were found. After interpolating these coefficients across the interferogram area, we obtained the water vapor correction by multiplying the coefficients by elevations. In this project, we tested three interpolation methods -- linear, spline, and cubic, but we found that there was little difference among these three methods. In order to test the result, we calculated the root mean square (RMS) phase of the data before and after correcting, and assessed the similarity of the correction between neighboring windows (i.e. the ‘coherence’ of the correction). We varied the sizes of windows to find the size which was most effective in removing signals, which have the highest coherence and significantly different RMS from others. However, the result we achieved was that: the smaller the window size the more signal the correction removed. Furthermore, when we conducted the same procedures using 10 other DEMs (i.e. DEMs of other places), we found the wrong DEMs also removed signals at a similar level of success to the correct DEM. In only 3 interferograms could we separate the correct DEM from the wrong ones without difficulties. Another thing worth mentioning is the method also removed the real deformation signals, e.g. uplifts and subsidence in the Santa Ana aquifer region. In conclusion then, the DEM-based corrections alone are not sufficient (in most circumstances) to correct for water vapor delay. The incorporation of GPS-derived water vapor delay estimates into these models would be a likely necessary improvement.

  20. Effects of DEM scale on the spatial distribution of the TOPMODEL topographic wetness index and its correlations to watershed characteristics

    NASA Astrophysics Data System (ADS)

    Drover, D. R.; Jackson, C. R.; Bitew, M.; Du, E.

    2015-11-01

    Topographic wetness indices (TWIs) calculated from digital elevation models (DEMs) are meant to predict relative landscape wetness and should have predictive power for soil and vegetation attributes. While previous researchers have shown cumulative TWI distributions shift to larger values as DEM resolution decreases, there has been little work assessing how DEM scales affect TWI spatial distributions and correlations with soil and vegetation properties. We explored how various DEM resolutions (2, 5, 10, 20, 30, and 50 m) subsampled from high definition LiDAR altered the spatial distribution of TWI values and the correlations of these values with soil characteristics determined from point samples, Natural Resources Conservation Service (NRCS) soil units, depths to groundwater, and managed vegetation distributions within a first order basin in the Upper Southeastern Coastal Plain with moderate slopes, flat valleys, and several wetlands. Point-scale soil characteristics were determined by laboratory analysis of point samples collected from riparian transects and hillslope grids. DEM scale affected the spatial distribution of TWI values in ways that affect our interpretation of landscape processes. At the finest DEM resolutions, valleys disappeared as TWI values were driven by local microtopography and not basin position. Spatial distribution of TWI values most closely matched the spatial distribution of soils, depth to groundwater, and vegetation stands for the 10, 20, and 30 m resolutions. DEM resolution affected the shape and direction of relationships between soil nitrogen and carbon contents and TWI values, but TWI values provided poor prediction of soil chemistry at all resolutions.

  1. A Study of the Novel of Otto Ludwig based on “Maria,” “Die Heiterethei u. i Widerspiel” and “Zwischen Himmel u. Erde”

    E-print Network

    Palmer, Emma Mae

    1909-01-01

    r e , i s a story of "diamond cut diamond". Hannesle,an undersized,diffident l i t t l e t a i l o r i s so tyrannized over by h i s mother that he decides he must marry some one who can protect him against her. A big strong t e r r o r of a g i r... s peaceably. "Zwischen Himmel und Erde" i s a story of twj brothers, s l a t e r s , by trade. F r i t z and Appllonius Nettenmair. Apollonius i s bash­ f u l and over conscientious while his brother i s the opposite. Apollonius, the "Träumer...

  2. Comparison of a Range of Terrain Variables Derived From DEMs Based on Different Resolutions and Input Data

    NASA Astrophysics Data System (ADS)

    Kienzle, S. W.

    2002-12-01

    It is a well-known fact that the grid cell size of a raster digital elevation model has significant effects on derived terrain variables such as slope, aspect, plan and profile curvature or the wetness index. This poster presents vital information for users of DEMs generated from 100 m regularly sampled, or similar, elevation points such as those available province-wide for Alberta, Canada. Findings are valid for flat to moderately sloped terrain present in the North American prairies and foothills regions and other locations with similar terrain. DEMs with grid cell sizes ranging from 100 to 5 m were interpolated from both 100 and 10 m regularly spaced elevation points using the ANUDEM interpolation method. Significant differences in a number of terrain variables derived from DEMs with different resolutions using cumulative distribution functions and a subsequent Kolmogorov-Smirnov test are revealed. Terrain variables based on 100 m regularly sampled elevation points (100 m DEM) are compared to a DEM based on 10 m regularly sampled elevation points which serves as a benchmark. Correlation analysis reveals that only elevation and slope have a strong positive relationship while all other terrain derivatives are not represented realistically. Relative root mean square errors quantify the quality of terrain derivatives. Major findings are summarised as follows: (a) All computed terrain variables tested (slope, aspect, plan and profile curvature, curvature and the wetness index) vary significantly with a change in grid cell size; (b) the higher the order of the derivative, the smaller the DEM resolution should be; (c) only elevation and slope show a high correlation between the 100 m DEM and the benchmark DEM; (d) the 100 m DEM can, therefore, only be used to show the general range and general spatial distribution of terrain variables, but fails - with the exception of slope - to represent spatially correctly the terrain variables at the associated scale.

  3. Integration of 2-D hydraulic model and high-resolution lidar-derived DEM for floodplain flow modeling

    NASA Astrophysics Data System (ADS)

    Shen, D.; Wang, J.; Cheng, X.; Rui, Y.; Ye, S.

    2015-08-01

    The rapid progress of lidar technology has made the acquirement and application of high-resolution digital elevation model (DEM) data increasingly popular, especially in regards to the study of floodplain flow. However, high-resolution DEM data pose several disadvantages for floodplain modeling studies; e.g., the data sets contain many redundant interpolation points, large numbers of calculations are required to work with data, and the data do not match the size of the computational mesh. Two-dimensional (2-D) hydraulic modeling, which is a popular method for analyzing floodplain flow, offers highly precise elevation parameterization for computational mesh while ignoring much of the micro-topographic information of the DEM data itself. We offer a flood simulation method that integrates 2-D hydraulic model results and high-resolution DEM data, thus enabling the calculation of flood water levels in DEM grid cells through local inverse distance-weighted interpolation. To get rid of the false inundation areas during interpolation, it employs the run-length encoding method to mark the inundated DEM grid cells and determine the real inundation areas through the run-length boundary tracing technique, which solves the complicated problem of connectivity between DEM grid cells. We constructed a 2-D hydraulic model for the Gongshuangcha detention basin, which is a flood storage area of Dongting Lake in China, by using our integrated method to simulate the floodplain flow. The results demonstrate that this method can solve DEM associated problems efficiently and simulate flooding processes with greater accuracy than simulations only with DEM.

  4. DEM modelling of the penetration process of the HP3 Mole

    NASA Astrophysics Data System (ADS)

    Poganski, J.; Kargl, G.; Schweiger, H.; Kömle, N.

    2015-10-01

    The NASA InSight Mission will be launched in March 2016 and will reach the surface of Mars roughly nine months later in the Elysium Region. One of the instruments on board is the HP³ Mole to measure the planetary heat flow. For this purpose it needs to penetrate five meters deep into the surface of Mars and thus offers also the possibility to analyse the soil properties. For the reconstruction of the soil behaviour and also to predict the mole performance and maximum reachable depth in advance, numerical simulations are used. The simulation of the soil during the hammering process of the HP³ Mole requires a substantial numerical effort due to the local high dynamics and large soil deformations that occur. After comparing the capability of various simulation methods (FEM, MPM and DEM) a discrete element method (DEM) was chosen.

  5. Coupled DEM-CFD Investigation of Granular Transport in a Fluid Channel

    NASA Astrophysics Data System (ADS)

    Zhao, T.; Dai, F.; Xu, N. W.

    2015-09-01

    This paper presents three dimensional numerical investigations of granular transport in fluids, analysed by the Discrete Element Method (DEM) coupled with Computational Fluid Mechanics (CFD). By employing this model, the relevance of flow velocity and granular depositional morphology has been clarified. The larger the flow velocity is, the further distance the grains can be transported to. In this process, the segregation of solid grains has been clearly identified. This research reveals that coarse grains normally accumulate near the grain source region, while the fine grains can be transported to the flow front. Regardless of the different flow velocities used in these simulations, the intensity of grains segregation remains almost unchanged. The results obtained from the DEM-CFD coupled simulations can reasonably explain the grain transport process occurred in natural environments, such as river scouring, evolution of river/ocean floor, deserts and submarine landslides.

  6. DEM generation and tidal deformation detection for sulzberger ice shelf, West Antarctica using SAR interferometry

    USGS Publications Warehouse

    Baek, S.; Kwoun, Oh-Ig; Bassler, M.; Lu, Zhiming; Shum, C.K.; Dietrich, R.

    2004-01-01

    In this study we generated a relative Digital Elevation Model (DEM) over the Sulzberger Ice Shelf, West Antarctica using ERS1/2 synthetic aperture radar (SAR) interferometry data. Four repeat pass differential interferograms are used to find the grounding zone and to classify the study area. An interferometrically derived DEM is compared with laser altimetry profile from ICESat. Standard deviation of the relative height difference is 5.12 m and 1.34 m in total length of the profile and at the center of the profile respectively. The magnitude and the direction of tidal changes estimated from interferogram are compared with those predicted tidal differences from four ocean tide models. Tidal deformation measured in InSAR is -16.7 cm and it agrees well within 3 cm with predicted ones from tide models.

  7. DEM simulation of particles of complex shapes using the multisphere method: Application for additive manufacturing

    NASA Astrophysics Data System (ADS)

    Parteli, Eric J. R.

    2013-06-01

    Additive manufacturing constitutes a promising production technology with potential application in a broad range of industrial areas. In this type of manufacturing process, objects are created from powder particles by adding layers of material upon one another through selectively melting particles from the powder bed. However, understanding the mechanical behavior of the powder during manufacturing as a function of material properties and particle shape is an essential pre-requisite for optimizing the production process. Here we develop a numerical tool for modeling the dynamics of powder particles during additive manufacturing based on force-based simulations by means of the Discrete Element Method (DEM). An existing DEM software (LIGGGHTS) is extended in order to study the transport of powder particles of complex geometric shapes through accounting for the boundary conditions inherent to the manufacturing process.

  8. The H? Diagnostic of Electron Heating: The Case of DEM L71

    NASA Astrophysics Data System (ADS)

    Rakowski, Cara E.; Ghavamian, Parviz; Laming, J. Martin

    2009-05-01

    Recently, the mechanisms and extent of immediate postshock heating of electrons at collisionless shocks have been under intense investigation. Several recent studies have suggested that the ratio of electron to proton temperature at the shock front scales approximately as the inverse square of the shock velocity. A specific interpretation of this dependence was first introduced by Ghavamian et al., who suggested electron heating by lower-hybrid waves in a cosmic ray (CR) precursor as a possible mechanism behind such a relationship. The best line diagnostics for the electron to proton temperature ratio behind collisionless shocks in partially neutral gas are the combination of broad and narrow H? lines emitted in the immediate vicinity of the shock front. In this work, we present extensive long-slit spectroscopy of the H? emission in the blast wave shock of supernova remnant DEM L71. We chose this remnant for two main reasons. First, the shock velocities in DEM L71 span the range of speeds where the electron to proton temperature ratio varies most rapidly with shock speed. Second, previous Fabry-Perot scans of the H? line complex indicated broad-to-narrow flux ratios lower than existing models predicted, but the spectral coverage of those observations was not broad enough to reliably measure the background emission around the broad component H? line. Our new high-resolution (R gsim 1600) spectra of DEM L71 provide extensive coverage of the background near the H? line and confirm our earlier Fabry-Perot results of consistently low (lsim1) broad-to-narrow flux ratios. Here, we present results of these observations and also outline the first results from spectra of radiative portions of DEM L71. We compare our results to the latest models of H? profiles from collisionless shocks. We conclude that the most likely explanation for the low broad-to-narrow flux ratio is the ionization and excitation of neutrals by electrons heated in the extended CR precursor.

  9. High resolution DEM from Tandem-X interferometry: an accurate tool to characterize volcanic activity

    NASA Astrophysics Data System (ADS)

    Albino, Fabien; Kervyn, Francois

    2013-04-01

    Tandem-X mission was launched by the German agency (DLR) in June 2010. It is a new generation high resolution SAR sensor mainly dedicated to topographic applications. For the purpose of our researches focused on the study of the volcano-tectonic activity in the Kivu Rift area, a set of Tandem-X bistatic radar images were used to produce a high resolution InSAR DEM of the Virunga Volcanic Province (VVP). The VVP is part of the Western branch of the African rift, situated at the boundary between D.R. Congo, Rwanda and Uganda. It has two highly active volcanoes, Nyiragongo and Nyamulagira. A first task concerns the quantitative assessment of the vertical accuracy that can be achieved with these new data. The new DEMs are compared to other space borne datasets (SRTM, ASTER) but also to field measurements given by differential GPS. Multi-temporal radar acquisitions allow us to produce several DEM of the same area. This appeared to be very useful in the context of an active volcanic context where new geomorphological features (faults, fissures, volcanic cones and lava flows) appear continuously through time. For example, since the year 2000, time of the SRTM acquisition, we had one eruption at Nyiragongo (2002) and six eruptions at Nyamulagira (2001, 2002, 2004, 2006, 2010 and 2011) which all induce large changes in the landscape with the emplacement of new lava fields and scoria cones. From our repetitive Tandem-X DEM production, we have a tool to identify and also quantify in term of size and volume all the topographic changes relative to this past volcanic activity. These parameters are high value information to improve the understanding of the Virunga volcanoes; the accurate estimation of erupted volume and knowledge of structural features associated to past eruptions are key parameters to understand the volcanic system, to ameliorate the hazard assessment, and finally contribute to risk mitigation in a densely populated area.

  10. Radiosensitization by misonidazole during recovery of cellular thiols following depletion by BSO or DEM.

    PubMed

    McNally, N J; Soranson, J A

    1989-05-01

    V79 cells have been depleted of their endogenous thiols by treatment with 100 microM BSO for 16-18 hr, or 0.5 mM DEM for 1 hr. The recovery of cellular thiols after removal of the drugs was determined by h.p.l.c. or flow cytometry and the sensitizer enhancement ratio for 100 microM misonidazole was measured as a function of time after removal of the drugs. The SER of 1.2 for control (hypoxic) cells increased to 1.8 for BSO treated (hypoxic) cells and 2.2 for DEM treated ones, when thiol levels were below 10% of controls. The SER and thiol levels returned to control values within 5 hr of removing DEM. After BSO there was little change during the first 5 hr and then a gradual return to normal values by 24 hrs. The major fall in the SER after removal of the drugs occurred as the cellular thiols increased to 60% of control values. PMID:2715087

  11. A Seamless, High-Resolution, Coastal Digital Elevation Model (DEM) for Southern California

    USGS Publications Warehouse

    Barnard, Patrick L.; Hoover, Daniel

    2010-01-01

    A seamless, 3-meter digital elevation model (DEM) was constructed for the entire Southern California coastal zone, extending 473 km from Point Conception to the Mexican border. The goal was to integrate the most recent, high-resolution datasets available (for example, Light Detection and Ranging (Lidar) topography, multibeam and single beam sonar bathymetry, and Interferometric Synthetic Aperture Radar (IfSAR) topography) into a continuous surface from at least the 20-m isobath to the 20-m elevation contour. This dataset was produced to provide critical boundary conditions (bathymetry and topography) for a modeling effort designed to predict the impacts of severe winter storms on the Southern California coast (Barnard and others, 2009). The hazards model, run in real-time or with prescribed scenarios, incorporates atmospheric information (wind and pressure fields) with a suite of state-of-the-art physical process models (tide, surge, and wave) to enable detailed prediction of water levels, run-up, wave heights, and currents. Research-grade predictions of coastal flooding, inundation, erosion, and cliff failure are also included. The DEM was constructed to define the general shape of nearshore, beach and cliff surfaces as accurately as possible, with less emphasis on the detailed variations in elevation inland of the coast and on bathymetry inside harbors. As a result this DEM should not be used for navigation purposes.

  12. A Review of Discrete Element Method (DEM) Particle Shapes and Size Distributions for Lunar Soil

    NASA Technical Reports Server (NTRS)

    Lane, John E.; Metzger, Philip T.; Wilkinson, R. Allen

    2010-01-01

    As part of ongoing efforts to develop models of lunar soil mechanics, this report reviews two topics that are important to discrete element method (DEM) modeling the behavior of soils (such as lunar soils): (1) methods of modeling particle shapes and (2) analytical representations of particle size distribution. The choice of particle shape complexity is driven primarily by opposing tradeoffs with total number of particles, computer memory, and total simulation computer processing time. The choice is also dependent on available DEM software capabilities. For example, PFC2D/PFC3D and EDEM support clustering of spheres; MIMES incorporates superquadric particle shapes; and BLOKS3D provides polyhedra shapes. Most commercial and custom DEM software supports some type of complex particle shape beyond the standard sphere. Convex polyhedra, clusters of spheres and single parametric particle shapes such as the ellipsoid, polyellipsoid, and superquadric, are all motivated by the desire to introduce asymmetry into the particle shape, as well as edges and corners, in order to better simulate actual granular particle shapes and behavior. An empirical particle size distribution (PSD) formula is shown to fit desert sand data from Bagnold. Particle size data of JSC-1a obtained from a fine particle analyzer at the NASA Kennedy Space Center is also fitted to a similar empirical PSD function.

  13. Applying DEM-SRTM for reconstructing a late Quaternary paleodrainage in Amazonia

    NASA Astrophysics Data System (ADS)

    Hayakawa, Ericson H.; Rossetti, Dilce F.; Valeriano, Márcio M.

    2010-08-01

    Remote sensing is a particularly invaluable tool that has helped the detection of paleomorphologies produced by river dislocation in a variety of landscapes, which has contributed in reconstructing the geological evolution of many fluvial systems. This technique might provide useful information to discuss the evolution of large fluvial systems, in special those located in areas of difficult access where the acquisition of field data is difficult. Application of remote sensing for paleodrainage characterization in densely vegetated tropical areas is scarce in the literature. This work records processing of the Digital Elevation Model (DEM) derived from the Shuttle Radar Topography Mission (SRTM), which succeeded in revealing an ancient drainage complex of the Madeira River, one of the main Amazonas tributaries, where other remote sensing products failed the detection. Analysis of this paleodrainage and of its modern counterpart within the geological framework available for this region leads to propose that activity along pre-existent faults during the latest Quaternary would have promoted the southeastward dislocation of a nearly 200 km long segment of the Madeira River. During this process, an impressive paleodrainage network was left behind, which was only able to be detected using the DEM-SRTM. Application of this technique might be of great help to the detection of paleodrainage morphologies in densely vegetated areas similar to the Amazonas lowland. The dynamics of channel migration in this and many other large scale tropical river systems might benefit from the investigation based on data derived from DEM-SRTM.

  14. Shoreline Mapping with Integrated HSI-DEM using Active Contour Method

    NASA Astrophysics Data System (ADS)

    Sukcharoenpong, Anuchit

    Shoreline mapping has been a critical task for federal/state agencies and coastal communities. It supports important applications such as nautical charting, coastal zone management, and legal boundary determination. Current attempts to incorporate data from hyperspectral imagery to increase the efficiency and efficacy of shoreline mapping have been limited due to the complexity in processing its data as well as its inferior spatial resolution when compared to multispectral imagery or to sensors such as LiDAR. As advancements in remote-sensing technologies increase sensor capabilities, the ability to exploit the spectral formation carried in hyperspectral images becomes more imperative. This work employs a new approach to extracting shorelines from AVIRIS hyperspectral images by combination with a LiDAR-based DEM using a multiphase active contour segmentation technique. Several techniques, such as study of object spectra and knowledge-based segmentation for initial contour generation, have been employed in order to achieve a sub-pixel level of accuracy and maintain low computational expenses. Introducing a DEM into hyperspectral image segmentation proves to be a useful tool to eliminate misclassifications and improve shoreline positional accuracy. Experimental results show that mapping shorelines from hyperspectral imagery and a DEM can be a promising approach as many further applications can be developed to exploit the rich information found in hyperspectral imagery.

  15. Energy Crisis in the Superbubble DEM L 192 (N 51D)

    E-print Network

    R. L. Cooper; M. A. Guerrero; Y. -H. Chu; C. -H. R. Chen; B. C. Dunne

    2004-01-21

    Superbubbles surrounding OB associations provide ideal laboratories to study the stellar energy feedback problem because the stellar energy input can be estimated from the observed stellar content of the OB associations and the interstellar thermal and kinetic energies of superbubbles are well-defined and easy to observe. We have used DEM L 192, also known as N 51D, to carry out a detailed case study of the energy budget in a superbubble, and we find that the expected amount of stellar mechanical energy injected into the ISM, (18+-5)x10^51 ergs, exceeds the amount of thermal and kinetic energies stored in the superbubble, (6+-2)x10^51 ergs. Clearly, a significant fraction of the stellar mechanical energy must have been converted to other forms of energy. The X-ray spectrum of the diffuse emission from DEM L 192 requires a power-law component to explain the featureless emission at 1.0-3.0 keV. The origin of this power-law component is unclear, but it may be responsible for the discrepancy between the stellar energy input and the observed interstellar energy in DEM L 192.

  16. Validation Of DEM Data Dvied From World View 3 Stero Imagery For Low Elevation Majuro Atoll, Marchall Islands

    EPA Science Inventory

    The availability of surface elevation data for the Marshall Islands has been identified as a "massive" data gap for conducting vulnerability assessments and the subsequent development of climate change adaption strategies. Specifically, digital elevation model (DEM) data are nee...

  17. Validation of DEM Data Derived from World View 3 Stereo Imagery for Low Elevation Majuro Atoll, Marshall Islands

    EPA Science Inventory

    The availability of surface elevation data for the Marshall Islands has been identified as a “massive” data gap for conducting vulnerability assessments and the subsequent development of climate change adaption strategies. Specifically, digital elevation model (DEM) data are need...

  18. DEM modelling, vegetation characterization and mapping of aspen parkland rangeland using LIDAR data

    NASA Astrophysics Data System (ADS)

    Su, Guangquan

    Detailed geographic information system (GIS) studies on plant ecology, animal behavior and soil hydrologic characteristics across spatially complex landscapes require an accurate digital elevation model (DEM). Following interpolation of last return LIDAR data and creation of a LIDAR-derived DEM, a series of 260 points, stratified by vegetation type, slope gradient and off-nadir distance, were ground-truthed using a total laser station, GPS, and 27 interconnected benchmarks. Despite an overall mean accuracy of +2 cm across 8 vegetation types, it created a RMSE (square root of the mean square error) of 1.21 m. DEM elevations were over-estimated within forested areas by an average of 20 cm with a RMSE of 1.05 m, under-estimated (-12 cm, RMSE = 1.36 m) within grasslands. Vegetation type had the greatest influence on DEM accuracy, while off-nadir distance (P = 0.48) and slope gradient (P = 0.49) did not influence DEM accuracy; however, the latter factors did interact (P < 0.10) to effect accuracy. Vegetation spatial structure (i.e., physiognomy) including plant height, cover, and vertical or horizontal heterogeneity, are important factors influencing biodiversity. Vegetation over and understory were sampled for height, canopy cover, and tree or shrub density within 120 field plots, evenly stratified by vegetation formation (grassland, shrubland, and aspen forest). Results indicated that LIDAR data could be used for estimating the maximum height, cover, and density, of both closed and semi-open stands of aspen (P < 0.001). However, LIDAR data could not be used to assess understory (<1.5 m) height within aspen stands, nor grass height and cover. Recognition and mapping of vegetation types are important for rangelands as they provide a basis for the development and evaluation of management policies and actions. In this study, LIDAR data were found to be superior to digital classification schedules for their mapping accuracy in aspen forest and grassland, but not shrubland. No single classification schedule created a high classification accuracy map for all types; however, the integration of LIDAR data and digital images achieved maps with corresponding overall accuracies of 91% and 83.9% with 3 and 8 classes of vegetation.

  19. Combined DEM Extration Method from StereoSAR and InSAR

    NASA Astrophysics Data System (ADS)

    Zhao, Z.; Zhang, J. X.; Duan, M. Y.; Huang, G. M.; Yang, S. C.

    2015-06-01

    A pair of SAR images acquired from different positions can be used to generate digital elevation model (DEM). Two techniques exploiting this characteristic have been introduced: stereo SAR and interferometric SAR. They permit to recover the third dimension (topography) and, at the same time, to identify the absolute position (geolocation) of pixels included in the imaged area, thus allowing the generation of DEMs. In this paper, StereoSAR and InSAR combined adjustment model are constructed, and unify DEM extraction from InSAR and StereoSAR into the same coordinate system, and then improve three dimensional positioning accuracy of the target. We assume that there are four images 1, 2, 3 and 4. One pair of SAR images 1,2 meet the required conditions for InSAR technology, while the other pair of SAR images 3,4 can form stereo image pairs. The phase model is based on InSAR rigorous imaging geometric model. The master image 1 and the slave image 2 will be used in InSAR processing, but the slave image 2 is only used in the course of establishment, and the pixels of the slave image 2 are relevant to the corresponding pixels of the master image 1 through image coregistration coefficient, and it calculates the corresponding phase. It doesn't require the slave image in the construction of the phase model. In Range-Doppler (RD) model, the range equation and Doppler equation are a function of target geolocation, while in the phase equation, the phase is also a function of target geolocation. We exploit combined adjustment model to deviation of target geolocation, thus the problem of target solution is changed to solve three unkonwns through seven equations. The model was tested for DEM extraction under spaceborne InSAR and StereoSAR data and compared with InSAR and StereoSAR methods respectively. The results showed that the model delivered a better performance on experimental imagery and can be used for DEM extraction applications.

  20. Insights on the emplacement of a compound lava flow field documented by a time series of Lidar-derived DEMs

    NASA Astrophysics Data System (ADS)

    Favalli, Massimiliano; Tarquini, Simone; Fornaciai, Alessandro

    2010-05-01

    The application of light detection and ranging (LIDAR) technology allows the production of high-resolution digital elevation models which are widely used in volcanological studies. Here we show a novel application of the airborne LIDAR technology which yields details of the volumetric rates and emplacement dynamics of an active lava flow field. During November 17-18, 2006, an airborne Lidar survey has been carried out at Mt. Etna on the upper slopes of the Valle del Bove (East flank) where a compound lava flow field was emplacing. The survey flight was specifically planned as a series of crossings (about 15' apart) over the flow field to repeatedly acquire a number of strips (one at each crossing) of the evolving lava channels. From each strip, a high resolution Digital Elevation Model (DEM) has been independently derived obtaining a time series of DEMs representing the evolution of the compound lava flow field. We derived volume changes in each acquisition interval by DEM subtraction. The analysis of the obtained series of DEM differences clearly shows that the emplacement of flow units is characterized by pulses of lava moving along lava channels. Lava fluxes have been derived for several flow units. Volumes and velocities of different pulses are uneven, highlighting a complex non linear emplacement of compound lava flows. These results have been obtained owing to a substantial improvement of three technical aspects: (1) the correction for systematic errors in raw LIDAR data; (2) the DEM-to-DEM coregistration; and (3) the precise quantification of residual errors.

  1. Coastal Digital Elevation Models (DEMs) for tsunami hazard assessment on the French coasts

    NASA Astrophysics Data System (ADS)

    Maspataud, Aurélie; Biscara, Laurie; Hébert, Hélène; Schmitt, Thierry; Créach, Ronan

    2015-04-01

    Building precise and up-to-date coastal DEMs is a prerequisite for accurate modeling and forecasting of hydrodynamic processes at local scale. Marine flooding, originating from tsunamis, storm surges or waves, is one of them. Some high resolution DEMs are being generated for multiple coast configurations (gulf, embayment, strait, estuary, harbor approaches, low-lying areas…) along French Atlantic and Channel coasts. This work is undertaken within the framework of the TANDEM project (Tsunamis in the Atlantic and the English ChaNnel: Definition of the Effects through numerical Modeling) (2014-2017). DEMs boundaries were defined considering the vicinity of French civil nuclear facilities, site effects considerations and potential tsunamigenic sources. Those were identified from available historical observations. Seamless integrated topographic and bathymetric coastal DEMs will be used by institutions taking part in the study to simulate expected wave height at regional and local scale on the French coasts, for a set of defined scenarii. The main tasks were (1) the development of a new capacity of production of DEM, (2) aiming at the release of high resolution and precision digital field models referred to vertical reference frameworks, that require (3) horizontal and vertical datum conversions (all source elevation data need to be transformed to a common datum), on the basis of (4) the building of (national and/or local) conversion grids of datum relationships based on known measurements. Challenges in coastal DEMs development deal with good practices throughout model development that can help minimizing uncertainties. This is particularly true as scattered elevation data with variable density, from multiple sources (national hydrographic services, state and local government agencies, research organizations and private engineering companies) and from many different types (paper fieldsheets to be digitized, single beam echo sounder, multibeam sonar, airborne laser bathymetric and topographic data, …) were gathered. Consequently, datasets were first assessed internally for both quality and accuracy and then externally with other to ensure consistency and gradual topographic/bathymetric transitioning along limits of the datasets. The heterogeneous ages of the input data also stress the importance of taking into account the temporal variability of bathymetric features, especially in the active areas (sandbanks, estuaries, channels). Locally, gaps between marine (hydrographic surveys) and terrestrial (topographic LIDAR) data have required the introduction of new methods and tools to solve interpolation. Through these activities the goal is to improve the production line and to enhance tools and procedures used for the improvement of processing, validation and qualification algorithms of bathymetric data, data collection work, automation of processing and integration process for conception of improved both bathymetric and topographic DEMs, merging data collected. This work is supported by a French ANR program in the frame of "Investissements d'Avenir", under the grant ANR-11-RSNR-00023-01.

  2. On the COSMO-SkyMed Exploitation for Interferometric DEM Generation

    NASA Astrophysics Data System (ADS)

    Teresa, C. M.; Raffaele, N.; Oscar, N. D.; Fabio, B.

    2011-12-01

    DEM products for Earth observation space-borne applications are being to play a role of increasing importance due to the new generation of high resolution sensors (both optical and SAR). These new sensors demand elevation data for processing and, on the other hand, they provide new possibilities for DEM generation. Till now, for what concerns interferometric DEM, the Shuttle Radar Topography Mission (SRTM) has been the reference product for scientific applications all over the world. SRTM mission [1] had the challenging goal to meet the requirements for a homogeneous and reliable DEM fulfilling the DTED-2 specifications. However, new generation of high resolution sensors (including SAR) pose new requirements for elevation data in terms of vertical precision and spatial resolution. DEM are usually used as ancillary input in different processing steps as for instance geocoding and Differential SAR Interferometry. In this context, the recent SAR missions of DLR (TerraSAR-X and TanDEM-X) and ASI (COSMO-SkyMed) can play a promising role thanks to their high resolution both in space and time. In particular, the present work investigates the potentialities of the COSMO/SkyMed (CSK) constellation for ground elevation measurement with particular attention devoted to the impact of the improved spatial resolution wrt the previous SAR sensors. The recent scientific works, [2] and [3], have shown the advantages of using CSK in the monitoring of terrain deformations caused by landslides, earthquakes, etc. On the other hand, thanks to the high spatial resolution, CSK appears to be very promising in monitoring man-made structures, such as buildings, bridges, railways and highways, thus enabling new potential applications (urban applications, precise DEM, etc.). We present results obtained by processing both SPOTLIGHT and STRIPMAP acquisitions through standard SAR Interferometry as well as multi-pass interferometry [4] with the aim of measuring ground elevation. Acknowledgments Work supported by ASI (Agenzia Spaziale Italiana) in the framework of the project "AO-COSMO Project ID-1462 - Feasibility of possible use of COSMO/SkyMed in bistatic SAR Earth observation - ASI Contract I/063/09/0". References [1] B. Rabus, M. Eineder, A. Roth, and R. Bamler, "The Shuttle Radar Topography Mission-A new class of digital elevation models acquired by spaceborne radar," ISPRS J. Photogramm. Remote Sens., vol. 57, no. 4, pp. 241-262, Feb. 2003. [2] F. BOVENGA, D. O. NITTI, R. NUTRICATO, M. T. CHIARADIA, "C- and X-band multi-pass InSAR analysis over Alpine and Apennine regions". In Proceedings of the European Space Agency Living Planet Symposium, June 28 - July 2, 2010, Bergen, Norway. [3] D. REALE, D. O. NITTI, D. PEDUTO, R. NUTRICATO, F. BOVENGA, G. FORNARO, "Postseismic Deformation Monitoring With The COSMO/SKYMED Constellation". IEEE Geoscience Remote Sensing Letters, 2011. DOI: 10.1109/LGRS.2010.2100364 [4] Nitti, D.O., Nutricato, R., Bovenga, F., Conte, D., Guerriero, L. & Milillo, G., "Quantitative Analysis of Stripmap And Spotlight SAR Interferometry with CosmoSkyMed constellation.", Proceedings if IEEE IGARSS 2009, July 13-17, 2009. Cape Town, South Africa.

  3. Coupling photogrammetric data with DFN-DEM model for rock slope hazard assessment

    NASA Astrophysics Data System (ADS)

    Donze, Frederic; Scholtes, Luc; Bonilla-Sierra, Viviana; Elmouttie, Marc

    2013-04-01

    Structural and mechanical analyses of rock mass are key components for rock slope stability assessment. The complementary use of photogrammetric techniques [Poropat, 2001] and coupled DFN-DEM models [Harthong et al., 2012] provides a methodology that can be applied to complex 3D configurations. DFN-DEM formulation [Scholtès & Donzé, 2012a,b] has been chosen for modeling since it can explicitly take into account the fracture sets. Analyses conducted in 3D can produce very complex and unintuitive failure mechanisms. Therefore, a modeling strategy must be established in order to identify the key features which control the stability. For this purpose, a realistic case is presented to show the overall methodology from the photogrammetry acquisition to the mechanical modeling. By combining Sirovision and YADE Open DEM [Kozicki & Donzé, 2008, 2009], it can be shown that even for large camera to rock slope ranges (tested about one kilometer), the accuracy of the data are sufficient to assess the role of the structures on the stability of a jointed rock slope. In this case, on site stereo pairs of 2D images were taken to create 3D surface models. Then, digital identification of structural features on the unstable block zone was processed with Sirojoint software [Sirovision, 2010]. After acquiring the numerical topography, the 3D digitalized and meshed surface was imported into the YADE Open DEM platform to define the studied rock mass as a closed (manifold) volume to define the bounding volume for numerical modeling. The discontinuities were then imported as meshed planar elliptic surfaces into the model. The model was then submitted to gravity loading. During this step, high values of cohesion were assigned to the discontinuities in order to avoid failure or block displacements triggered by inertial effects. To assess the respective role of the pre-existing discontinuities in the block stability, different configurations have been tested as well as different degree of fracture persistency in order to enhance the possible contribution of rock bridges on the failure surface development. It is believed that the proposed methodology can bring valuable complementary information for rock slope stability analysis in presence of complex fractured system for which classical "Factor of Safety" is difficult to express. References • Harthong B., Scholtès L. & F.V. Donzé, Strength characterization of rock masses, using a coupled DEM-DFN model, Geophysical Journal International, doi: 10.1111/j.1365-246X.2012.05642.x, 2012. • Kozicki J & Donzé FV. YADE-OPEN DEM: an open--source software using a discrete element method to simulate granular material, Engineering Computations, 26(7):786-805, 2009 • Kozicki J, Donzé FV. A new open-source software developed for numerical simulations using discrete modeling methods, Comp. Meth. In Appl. Mech. And Eng. 197:4429-4443, 2008. • Poropat, G.V., New methods for mapping the structure of rock masses. In Proceedings, Explo 2001, Hunter Valley, New South Wales, 28-31 October 2001, pp. 253-260, 2001. • Scholtès, L. & Donzé FV. Modelling progressive failure in fractured rock masses using a 3D discrete element method, International Journal of Rock Mechanics and Mining Sciences, 52:18-30, 2012a. • Scholtès, L. & Donzé, F.-V., DEM model for soft and hard rocks: role of grain interlocking on strength, J. Mech. Phys. Solids, doi: 10.1016/j.jmps.2012.10.005, 2012b. • Sirovision, Commonwealth Scientific and Industrial Research Organisation CSIRO, Siro3D Sirovision 3D Imaging Mapping System Manual Version 4.1, 2010

  4. A real-time flood forecasting and simulation system based on GIS and DEM: Analysis of sensitivity to scale factors

    NASA Astrophysics Data System (ADS)

    Garcia, Sandra G.

    The hydrometeorological telemetric networks in real time interrelated with weather forecasting and rainfall information obtained from remote sensing, constitute real forecasting and protection instruments in the event of flash flooding, so typical of semiarid environments. In this Thesis, spatial analysis approached with functions embedded in a Geographical Information System (GIS) are proposed. The aims are: (a) To combine efficiently information from different sources (telemetric networks and radar-satellite technology). (b) To develop methodology of application of spatially distributed and hybrid hydrologic models, which are topographically based and event-oriented. (c) To extract automatically from Digital Elevation Models (DEM) the relevant parameters of the hydrologic models used. When extracting the drainage networks from a DEM, various questions arise: what is the most suitable drainage density for the hydrographic network? What degree of affection does the selection of DEM cell size have on the hydrologic results, or are they not sensitive to it? Can any invariable property by defined with the scale which characterizes indexes or parameters based on the drainage network hierarchy? A clear inter-relationship can be seen between the geomorphological and hydrologic parameters and the DEM resolution. The morphometric parameters are also affected by threshold area variation. It is proposed a methodology to identify a priori the range of DEM resolutions and threshold areas for in which the parameters present a certain stability for modelling based on drainage networks topology. When working with spatially distributed models, several questions crop up: Are the distributed parameters derived from DEM and the complete hydrologic results affected by cell size? Is it feasible to identify invariable properties with the scale which characterizes the spatial distributions of the parameters? The terrain slope and the flow path length are affected by the DEM cell-size adopted. The spatially distributed flow velocity presents invariance properties with the DEM scale, founded on the behaviour of the cumulative drainage area distribution curve. Thus, the hydrographs simulated by means of distributed UH models, present slight sensitivity to the DEM cell size. Scale exponents, invariable with DEM resolution, of power distributions which characterize the behaviour of certain distributed parameters, have been identified.

  5. Stream Morphologic Measurements from Airborne Laser Swath Mapping: Comparisons with Field Surveys, Traditional DEMs, and Aerial Photographs

    NASA Astrophysics Data System (ADS)

    Snyder, N. P.; Schultz, L. L.

    2005-12-01

    Precise measurement of stream morphology over entire watersheds is one of the great research opportunities provided by airborne laser swath mapping (ALSM). ALSM surveys allow for rapid quantification of factors, such as channel width and gradient, that control stream hydraulic and ecologic properties. We compare measurements from digital elevation models (DEMs) derived from ALSM data collected by the National Center for Airborne Laser Mapping (NCALM) to field surveys, traditional DEMs (rasterized from topographic maps), and aerial photographs. The field site is in the northern Black Mountains in arid Death Valley National Park (California). The area is unvegetated, and therefore is excellent for testing DEM analysis methods because the ALSM data required minimal filtering, and the resulting DEM contains relatively few unphysical sinks. Algorithms contained in geographic information systems (GIS) software used to extract stream networks from DEMs yield best results where streams are steep enough for resolvable pixel-to-pixel elevation change, and channel width is on the order of pixel resolution. This presents a new challenge with ALSM-derived DEMs because the pixel size (1 m) is often an order of magnitude or more smaller than channel width. We find the longitudinal profile of Gower Gulch in the northern Black Mountains (~4 km total length) extracted using the ALSM DEM and a flow accumulation algorithm is 14% longer than a traditional 10-m DEM, and 13% longer than a field survey. These differences in length (and therefore gradient) are due to the computed channel path following small-scale topographic variations within the channel bottom that are not relevant during high flows. However, visual analysis of shaded-relief images created from high-resolution ALSM data is an excellent method for digitizing channel banks and thalweg paths. We used these lines to measure distance, elevation, and width. In Gower Gulch, the algorithm-derived profile is 10% longer than that measured by tracing the thalweg on the ALSM imagery. By obtaining longitudinal profiles and widths from the same dataset, ALSM represents a major step forward from previous remote-sensing morphologic analyses, in which profiles are measured using traditional DEMs or topographic maps, and widths from aerial photographs. These combined analyses would be particularly powerful in regions of low relief and/or wide channels were traditional DEMs have limited utility.

  6. Computer vision: automating DEM generation of active lava flows and domes from photos

    NASA Astrophysics Data System (ADS)

    James, M. R.; Varley, N. R.; Tuffen, H.

    2012-12-01

    Accurate digital elevation models (DEMs) form fundamental data for assessing many volcanic processes. We present a photo-based approach developed within the computer vision community to produce DEMs from a consumer-grade digital camera and freely available software. Two case studies, based on the Volcán de Colima lava dome and the Puyehue Cordón-Caulle obsidian flow, highlight the advantages of the technique in terms of the minimal expertise required, the speed of data acquisition and the automated processing involved. The reconstruction procedure combines structure-from-motion and multi-view stereo algorithms (SfM-MVS) and can generate dense 3D point clouds (millions of points) from multiple photographs of a scene taken from different positions. Processing is carried out by automated software (e.g. http://blog.neonascent.net/archives/bundler-photogrammetry-package/). SfM-MVS reconstructions are initally un-scaled and un-oriented so additional geo-referencing software has been developed. Although this step requires the presence of some control points, the SfM-MVS approach has significantly easier image acquisition and control requirements than traditional photogrammetry, facilitating its use in a broad range of difficult environments. At Colima, the lava dome surface was reconstructed from recent and archive images taken from light aircraft over flights (2007-2011). Scaling and geo-referencing was carried out using features identified in web-sourced ortho-imagery obtained as a basemap layer in ArcMap - no ground-based measurements were required. Average surface measurement densities are typically 10-40 points per m2. Over mean viewing distances of ~500-2500 m (for different surveys), RMS error on the control features is ~1.5 m. The derived DEMs (with 1-m grid resolution) are sufficient to quantify volumetric change, as well as to highlight the structural evolution of the upper surface of the dome following an explosion in June 2011. At Puyehue Cordón-Caulle, images of the active lava flow were taken on foot from a ridge overlooking the flow. To assess the evolution of the flow front, two DEMs were derived from collections of ~400 images taken on different days. To scale and geo-reference the data, one image sequence was accompanied by simultaneous collection of a GPS track using a consumer handheld GPS unit; no control points were used. The second survey was then scaled and georeferenced to the first, using features identifiable in both image sets, giving an RMS error of ~0.22 m. DEM comparison then allows advance rates and mechanisms to be identified, and comparisons drawn with emplacement processes of basaltic flows. In both case studies, the SfM-MVS approach allowed DEM generation when access or lack of dedicated surveying equipment and expertise prevented standard techniques from being deployed.olima dome 2011: 3D point cloud data

  7. Reanalysis of the DEMS nested case-control study of lung cancer and diesel exhaust: suitability for quantitative risk assessment.

    PubMed

    Crump, Kenny S; Van Landingham, Cynthia; Moolgavkar, Suresh H; McClellan, Roger

    2015-04-01

    The International Agency for Research on Cancer (IARC) in 2012 upgraded its hazard characterization of diesel engine exhaust (DEE) to "carcinogenic to humans." The Diesel Exhaust in Miners Study (DEMS) cohort and nested case-control studies of lung cancer mortality in eight U.S. nonmetal mines were influential in IARC's determination. We conducted a reanalysis of the DEMS case-control data to evaluate its suitability for quantitative risk assessment (QRA). Our reanalysis used conditional logistic regression and adjusted for cigarette smoking in a manner similar to the original DEMS analysis. However, we included additional estimates of DEE exposure and adjustment for radon exposure. In addition to applying three DEE exposure estimates developed by DEMS, we applied six alternative estimates. Without adjusting for radon, our results were similar to those in the original DEMS analysis: all but one of the nine DEE exposure estimates showed evidence of an association between DEE exposure and lung cancer mortality, with trend slopes differing only by about a factor of two. When exposure to radon was adjusted, the evidence for a DEE effect was greatly diminished, but was still present in some analyses that utilized the three original DEMS DEE exposure estimates. A DEE effect was not observed when the six alternative DEE exposure estimates were utilized and radon was adjusted. No consistent evidence of a DEE effect was found among miners who worked only underground. This article highlights some issues that should be addressed in any use of the DEMS data in developing a QRA for DEE. PMID:25857246

  8. Reanalysis of the DEMS Nested Case-Control Study of Lung Cancer and Diesel Exhaust: Suitability for Quantitative Risk Assessment

    PubMed Central

    Crump, Kenny S; Van Landingham, Cynthia; Moolgavkar, Suresh H; McClellan, Roger

    2015-01-01

    The International Agency for Research on Cancer (IARC) in 2012 upgraded its hazard characterization of diesel engine exhaust (DEE) to “carcinogenic to humans.” The Diesel Exhaust in Miners Study (DEMS) cohort and nested case-control studies of lung cancer mortality in eight U.S. nonmetal mines were influential in IARC’s determination. We conducted a reanalysis of the DEMS case-control data to evaluate its suitability for quantitative risk assessment (QRA). Our reanalysis used conditional logistic regression and adjusted for cigarette smoking in a manner similar to the original DEMS analysis. However, we included additional estimates of DEE exposure and adjustment for radon exposure. In addition to applying three DEE exposure estimates developed by DEMS, we applied six alternative estimates. Without adjusting for radon, our results were similar to those in the original DEMS analysis: all but one of the nine DEE exposure estimates showed evidence of an association between DEE exposure and lung cancer mortality, with trend slopes differing only by about a factor of two. When exposure to radon was adjusted, the evidence for a DEE effect was greatly diminished, but was still present in some analyses that utilized the three original DEMS DEE exposure estimates. A DEE effect was not observed when the six alternative DEE exposure estimates were utilized and radon was adjusted. No consistent evidence of a DEE effect was found among miners who worked only underground. This article highlights some issues that should be addressed in any use of the DEMS data in developing a QRA for DEE. PMID:25857246

  9. Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM): A Year 2000 Global Baseline for Measuring Topographic Change

    NASA Astrophysics Data System (ADS)

    Crippen, R. E.

    2002-12-01

    The SRTM DEM is the first near-global, high-resolution elevation model. The data were acquired in February 2000 aboard the Space Shuttle Endeavour and cover the Earth's land masses between 60N and 56S latitudes at about 30 meters spatial resolution. The data are a virtual global snapshot in that they were acquired in about 10 days by a single sensor. Absolute vertical accuracy was targeted at 16 meters. However, spatially broad temporal changes in topography have been detected and measured down to about one-meter precision by comparing the SRTM DEM to the USGS National Elevation Dataset (NED). NED has similar spatial properties, but was independently derived, commonly years (or decades) earlier. Such changes already noted include those related to volcanic processes, alluvial fan deposition, subsidence related to oil extraction, and direct anthropogenic changes such as landfills and major road cuts and fills. Large tectonic changes in topography are likewise potentially evident in such comparisons. New and forthcoming satellites include capabilities to produce elevation models that can be used to detect and measure ongoing and future topographic change when compared to the SRTM DEM. For example, the ASTER instrument on the Terra satellite (launched in 1999) produces targeted DEMs, and SPOT-5 (launched in 2002) is expected to produce a global DEM over a five-year period. Both of these DEM sources (and the NED and others) use optical wavelength sensors which may "observe a different surface" than the SRTM radar, particularly in heavily vegetated areas, and this must be considered in making the comparisons. However, having a "before" data set is often the roadblock in measuring change, and SRTM has now provided the first detailed "before" DEM for most of Earth's land surface.

  10. Sensitivity of watershed attributes to spatial resolution and interpolation method of LiDAR DEMs in three distinct landscapes

    NASA Astrophysics Data System (ADS)

    Goulden, T.; Hopkinson, C.; Jamieson, R.; Sterling, S.

    2014-03-01

    This study investigates scaling relationships of watershed area and stream networks delineated from LiDAR DEMs. The delineations are tested against spatial resolution, including 1, 5, 10, 25, and 50 m, and interpolation method, including Inverse Distance Weighting (IDW), Moving Average (MA), Universal Kriging (UK), Natural Neighbor (NN), and Triangular Irregular Networks (TIN). Study sites include Mosquito Creek, Scotty Creek, and Thomas Brook, representing landscapes with high, low, and moderate change in elevation, respectively. Results show scale-dependent irregularities in watershed area due to spatial resolution at Thomas Brook and Mosquito Creek. The highest sensitivity of watershed area to spatial resolution occurred at Scotty Creek, due to high incidence of LiDAR sensor measurement error and subtle changes in elevation. Length of drainage networks did not show a scaling relationship with spatial resolution, due to algorithmic complications of the stream initiation threshold. Stream lengths of main channels at Thomas Brook and Mosquito Creek displayed systematic increases in length with increasing spatial resolution, described through an average fractal dimension of 1.059. The scaling relationship between stream length and DEM resolution allows estimation of stream lengths from low-resolution DEMs in the absence of high-resolution DEMs. Single stream validation at Thomas Brook showed the 1 m DEM produced the lowest length error and highest spatial accuracy, at 3.7% and 71.3%, respectively. Single stream validation at Mosquito Creek showed the 25 m DEM produced the lowest length error, and the 1 m DEM the highest spatial accuracy, at 0.6% and 61.0%, respectively.

  11. Evaluation of TanDEM-X elevation data for geomorphological mapping and interpretation in high mountain environments - A case study from SE Tibet, China

    NASA Astrophysics Data System (ADS)

    Pipaud, Isabel; Loibl, David; Lehmkuhl, Frank

    2015-10-01

    Digital elevation models (DEMs) are a prerequisite for many different applications in the field of geomorphology. In this context, the two near-global medium resolution DEMs originating from the SRTM and ASTER missions are widely used. For detailed geomorphological studies, particularly in high mountain environments, these datasets are, however, known to have substantial disadvantages beyond their posting, i.e., data gaps and miscellaneous artifacts. The upcoming TanDEM-X DEM is a promising candidate to improve this situation by application of state-of-the-art radar technology, exhibiting a posting of 12 m and less proneness to errors. In this study, we present a DEM processed from a single TanDEM-X CoSSC scene, covering a study area in the extreme relief of the eastern Nyainqêntanglha Range, southeastern Tibet. The potential of the resulting experimental TanDEM-X DEM for geomorphological applications was evaluated by geomorphometric analyses and an assessment of landform cognoscibility and artifacts in comparison to the ASTER GDEM and the recently released SRTM 1? DEM. Detailed geomorphological mapping was conducted for four selected core study areas in a manual approach, based exclusively on the TanDEM-X DEM and its basic derivates. The results show that the self-processed TanDEM-X DEM yields a detailed and widely consistent landscape representation. It thus fosters geomorphological analysis by visual and quantitative means, allowing delineation of landforms down to footprints of ~ 30 m. Even in this premature state, the TanDEM-X elevation data are widely superior to the ASTER and SRTM datasets, primarily owing to its significantly higher resolution and its lower susceptibility to artifacts that hamper landform interpretation. Conversely, challenges toward interferometric DEM generation were identified, including (i) triangulation facets and missing topographic information resulting from radar layover on steep slopes facing toward the radar sensor, (ii) low coherence values on leeward slopes, (iii) decorrelation effects over water bodies, and (iv) challenges for phase unwrapping in settings of strong topographic contrasts. There is, however, a high probability that these drawbacks can be overcome by applying multiple interferograms exhibiting different perpendicular baselines as planned for the generation of the final TanDEM-X DEM product.

  12. Collection of medical drug information in pharmacies: Drug Event Monitoring (DEM) in Japan.

    PubMed

    Hayashi, Sei-ichiro; Nanaumi, Akira; Akiba, Yasuji; Komiyama, Takako; Takeuchi, Koichi

    2005-07-01

    To establish a system for collecting and reporting information from community pharmacists such as that on adverse effects, the Japan Pharmaceutical Association (JPA) conducts Drug Event Monitoring (DEM). In the fiscal year 2002, a survey was carried out to clarify the incidence of sleepiness due to antiallergic drugs. The investigated active ingredients were ebastine, fexofenadine hydrochloride, cetirizine hydrochloride, and loratadine. Community pharmacists asked the following question to patients who visited their pharmacies: "Have you ever become sleepy after taking this drug?" During a 4-week survey period, reports of 94256 cases were collected. To evaluate the incidence of sleepiness, we analyzed cases in which reports showed alleged absence of concomitant oral drugs, and drug use in conformity with the dose and method described in package inserts. The incidence of sleepiness was significantly different among the drugs (chi(2)-test, p<0.001). The observed incidences of sleepiness due to the drugs (8.8-20.5%) were higher than those described in each package insert (1.8-6.35%). This may be because an active question was used ("Have you ever become sleepy after taking this drug?"). Active intervention by pharmacists may be useful for collecting more information on improvement in the QOL of patients and safety. In addition, the pharmacists were asked to report events other than "sleepiness" in the free description column of the report. Some symptoms not described in the package inserts were reported, suggesting that DEM may lead to the discovery of new adverse effects. These results suggest that community pharmacists have a good opportunity to collect information in DEM, and safety information such as that on adverse effects can be obtained from pharmacies. PMID:15997212

  13. Evaluation of Elevation, Slope and Stream Network Quality of SPOT Dems

    NASA Astrophysics Data System (ADS)

    El Hage, M.; Simonetto, E.; Faour, G.; Polidori, L.

    2012-07-01

    Digital elevation models are considered the most useful data for dealing with geomorphology. The quality of these models is an important issue for users. This quality concerns position and shape. Vertical accuracy is the most assessed in many studies and shape quality is often neglected. However, both of them have an impact on the quality of the final results for a particular application. For instance, the elevation accuracy is required for orthorectification and the shape quality for geomorphology and hydrology. In this study, we deal with photogrammetric DEMs and show the importance of the quality assessment of both elevation and shape. For this purpose, we produce several SPOT HRV DEMs with the same dataset but with different template size, that is one of the production parameters from optical images. Then, we evaluate both elevation and shape quality. The shape quality is assessed with in situ measurements and analysis of slopes as an elementary shape and stream networks as a complex shape. We use the fractal dimension and sinuosity to evaluate the stream network shape. The results show that the elevation accuracy as well as the slope accuracy are affected by the template size. Indeed, an improvement of 1 m in the elevation accuracy and of 5 degrees in the slope accuracy has been obtained while changing this parameter. The elevation RMSE ranges from 7.6 to 8.6 m, which is smaller than the pixel size (10 m). For slope, the RMSE depends on the sampling distance. With a distance of 10 m, the minimum slope RMSE is 11.4 degrees. The stream networks extracted from these DEMs present a higher fractal dimension than the reference river. Moreover, the fractal dimension of the extracted networks has a negligible change according to the template size. Finally, the sinuosity of the stream networks is slightly affected by the change of the template size.

  14. DEM L241, A SUPERNOVA REMNANT CONTAINING A HIGH-MASS X-RAY BINARY

    SciTech Connect

    Seward, F. D.; Charles, P. A.; Foster, D. L.; Dickel, J. R.; Romero, P. S.; Edwards, Z. I.; Perry, M.; Williams, R. M.

    2012-11-10

    A Chandra observation of the Large Magellanic Cloud supernova remnant DEM L241 reveals an interior unresolved source which is probably an accretion-powered binary. The optical counterpart is an O5III(f) star making this a high-mass X-ray binary with an orbital period likely to be of the order of tens of days. Emission from the remnant interior is thermal and spectral information is used to derive density and mass of the hot material. Elongation of the remnant is unusual and possible causes of this are discussed. The precursor star probably had mass >25 M {sub Sun}.

  15. A 3D DEM-LBM approach for the assessment of the quick condition for sands

    NASA Astrophysics Data System (ADS)

    Mansouri, M.; Delenne, J.-Y.; El Youssoufi, M. S.; Seridi, A.

    2009-09-01

    We present a 3D numerical model to assess the quick condition (the onset of the boiling phenomenon) in a saturated polydisperse granular material. We use the Discrete Element Method (DEM) to study the evolution of the vertical intergranular stress in a granular sample subjected to an increasing hydraulic gradient. The hydrodynamic forces on the grains of the sample are computed using the Lattice Boltzmann Method (LBM). The principal assumption used is that grains remain at rest until the boiling onset. We show that the obtained critical hydraulic gradient is close to that defined in classical soil mechanics. To cite this article: M. Mansouri et al., C. R. Mecanique 337 (2009).

  16. Development of high-resolution coastal DEMs: Seamlessly integrating bathymetric and topographic data to support coastal inundation modeling

    NASA Astrophysics Data System (ADS)

    Eakins, B. W.; Taylor, L. A.; Warnken, R. R.; Carignan, K. S.; Sharman, G. F.

    2006-12-01

    The National Geophysical Data Center (NGDC), an office of the National Oceanic and Atmospheric Administration (NOAA), is cooperating with the NOAA Pacific Marine Environmental Laboratory (PMEL), Center for Tsunami Research to develop high-resolution digital elevation models (DEMs) of combined bathymetry and topography. The coastal DEMs will be used as input for the Method of Splitting Tsunami (MOST) model developed by PMEL to simulate tsunami generation, propagation and inundation. The DEMs will also be useful in studies of coastal inundation caused by hurricane storm surge and rainfall flooding, resulting in valuable information for local planners involved in disaster preparedness. We present our methodology for creating the high-resolution coastal DEMs, typically at 1/3 arc-second (10 meters) cell size, from diverse digital datasets collected by numerous methods, in different terrestrial environments, and at various scales and resolutions; one important step is establishing the relationships between various tidal and geodetic vertical datums, which may vary over a gridding region. We also discuss problems encountered and lessons learned, using the Myrtle Beach, South Carolina DEM as an example.

  17. Comparison of elevation derived from insar data with dem from topography map in Son Dong, Bac Giang, Viet Nam

    NASA Astrophysics Data System (ADS)

    Nguyen, Duy

    2012-07-01

    Digital Elevation Models (DEMs) are used in many applications in the context of earth sciences such as in topographic mapping, environmental modeling, rainfall-runoff studies, landslide hazard zonation, seismic source modeling, etc. During the last years multitude of scientific applications of Synthetic Aperture Radar Interferometry (InSAR) techniques have evolved. It has been shown that InSAR is an established technique of generating high quality DEMs from space borne and airborne data, and that it has advantages over other methods for the generation of large area DEM. However, the processing of InSAR data is still a challenging task. This paper describes InSAR operational steps and processing chain for DEM generation from Single Look Complex (SLC) SAR data and compare a satellite SAR estimate of surface elevation with a digital elevation model (DEM) from Topography map. The operational steps are performed in three major stages: Data Search, Data Processing, and product Validation. The Data processing stage is further divided into five steps of Data Pre-Processing, Co-registration, Interferogram generation, Phase unwrapping, and Geocoding. The Data processing steps have been tested with ERS 1/2 data using Delft Object-oriented Interferometric (DORIS) InSAR processing software. Results of the outcome of the application of the described processing steps to real data set are presented.

  18. Automatic Detection and Boundary Extraction of Lunar Craters Based on LOLA DEM Data

    NASA Astrophysics Data System (ADS)

    Li, Bo; Ling, ZongCheng; Zhang, Jiang; Wu, ZhongChen

    2015-07-01

    Impact-induced circular structures, known as craters, are the most obvious geographic and geomorphic features on the Moon. The studies of lunar carters' patterns and spatial distributions play an important role in understanding geologic processes of the Moon. In this paper, we proposed a method based on digital elevation model (DEM) data from lunar orbiter laser altimeter to detect the lunar craters automatically. Firstly, the DEM data of study areas are converted to a series of spatial fields having different scales, in which all overlapping depressions are detected in order (larger depressions first, then the smaller ones). Then, every depression's true boundary is calculated by Fourier expansion and shape parameters are computed. Finally, we recognize the craters from training sets manually and build a binary decision tree to automatically classify the identified depressions into craters and non-craters. In addition, our crater-detection method can provides a fast and reliable evaluation of ages of lunar geologic units, which is of great significance in lunar stratigraphy studies as well as global geologic mapping.

  19. Region-growing segmentation to automatically delimit synthetic drumlins in 'real' DEMs

    NASA Astrophysics Data System (ADS)

    Eisank, Clemens; Smith, Mike; Hillier, John

    2013-04-01

    Mapping or 'delimiting' landforms is one of geomorphology's primary tools. Computer-based techniques, such as terrain segmentation, may potentially provide terrain units that are close to the size and shape of landforms. Whether terrain units represent landforms heavily depends on the segmentation algorithm, its settings and the type of underlying land-surface parameters (LSPs). We assess a widely used region-growing technique, i.e. the multiresolution segmentation (MRS) algorithm as implemented in object-based image analysis software, for delimiting drumlins. Supervised testing was based on five synthetic DEMs that included the same set of perfectly known drumlins at different locations. This, for the first time, removes subjectivity from the reference data. Five LSPs were tested, and four variants were computed for each using two pre- and post-processing options. The automated method (1) employs MRS to partition the input LSP into 200 ever coarser terrain unit patterns, (2) identifies the spatially best matching terrain unit for each reference drumlin, and (3) computes four accuracy metrics for quantifying the aerial match between delimited and reference drumlins. MRS performed best on LSPs that are regional, derived from a decluttered DEM and then normalized. Median scale parameters (SPs) for segments best delineating drumlins were relatively stable for the same LSP, but varied significantly between LSPs. Larger drumlins were generally delimited at higher SPs. MRS indicated high robustness against variations in the location and distribution of drumlins.

  20. Micro relief parameters from high resolution DEMs as representative values for physical based soil erosion models

    NASA Astrophysics Data System (ADS)

    Neugirg, Fabian; Kaiser, Andreas; Haas, Florian; Veh, Georg; Schindewolf, Marcus; Schmidt, Jürgen; Becht, Michael

    2014-05-01

    Field parameters, such as hydraulic roughness are indispensable for modeling soil erosion on a physical base. Established approaches to acquire parameters for hydraulic roughness are based on flow velocity, flow volume and the slope angle. Other methods refer to grain sizes affecting a volume flow as an indicator for roughness. This work presents a remote sensing approach to generate high resolution surface reconstructions of rough terrain in different scales. As the ability of producing high resolution digital elevation models (DEM) is rapidly increasing over the last years, the possibilities of morphometric analysis of micro reliefs are also constantly developing. Point spacings of very dense point clouds acquired with the help of terrestrial laserscanning or structure from motion are minimal. Thus, even small grain sizes and inhomogeneity can be identified in the DEMs. Surface models used for this study were acquired in advance and afterwards simulated flow and rainfall events. Resulting changes in surface roughness caused by fluvial erosion could be detected on bare soil and sparsely vegetated areas. To validate the measured roughness values flow velocities and flow volumes were regularly recorded during the events. This work aims to present a step forward to standardizing new methods in data acquisition in soil erosion modeling.

  1. Monitoring water levels by integrating optical and synthetic aperture radar water masks with lidar DEMs

    NASA Astrophysics Data System (ADS)

    Hopkinson, C.; Brisco, B.; Patterson, S.

    2014-12-01

    The ability to map and monitor wetland and lake open water extent and levels across the landscape allows improved estimates of watershed water balance, surface storage and flood inundation. The study presents open water classifications over the wetland dominated Sheppard Slough watershed east of Calgary in western Canada using parallel temporal imagery captured from the RapidEye and RadarSat satellites throughout 2013, a year of widespread and costly flood inundation in this region. The optical and SAR-based temporal image stacks were integrated with a high-resolution lidar DEM in order to delineate regions of inundation on the DEM surface. GIS techniques were developed to extract lidar-derived water surface elevations and track the spatio-temporal variation in pond and lake water level across the watershed. Water bodies were assigned unique identifiers so that levels could be tracked and linked to their associated watershed channel reach. The procedure of optical image classification through to merging of individual water bodies into watershed channel topology and extracting reach water levels has been automated within python scripts. The presentation will describe: i) the procedures used; ii) a comparison of the SAR and optical classification and water level extraction results; iii) a discussion of the spatio-temporal variations in water level across the Sheppard Slough watershed; and iv) a commentary on how the approach could be implemented for web-based operational monitoring and as simulation initialisation inputs for flood inundation model studies.

  2. Assessing volume change of tropical Peruvian glaciers from multi-temporal digital elevation models (DEMs)

    NASA Astrophysics Data System (ADS)

    Huh, K.; Mark, B. G.

    2012-12-01

    Although far smaller than large polar ice caps, mountain glaciers are significant contributors to sea level rise and tropical glaciers in particular are sources of critical water resources to regional societies. The glaciers in Cordillera Blanca, the Andes of Peru, hold important environmental and economic concerns of regional water supplies to communities in the arid western part of the country under continued global climate change. Yet steep relief and remote locations present challenges for measuring mass changes in tropical glaciers. Remotely sensed images provide feasible opportunities to measure glacier surface area changes. We use a combination of satellite and airborne remote sensing, digital photogrammetry and geospatial techniques to assess the surface area, volume and topographic changes of key glaciers in the Cordillera Blanca, Peru between 1962 and 2008. The intercomparison of digital elevation models (DEMs) from airborne Light Detection and Range (LiDAR) data of 2008, multispectral Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) of 2001-2008 and stereo-paired airborne photographs of 1962 for deriving elevation differences over time reveal the data quality to measure the volume loss in the area. The DEMs over non-glacier areas in the study sites were selected and differentially corrected Global Positioning System (dGPS) data points were used for comparison as well. The motivation of this study is to refine a surface area to volume scaling for tropical glaciers to enable extrapolation of more detailed inventory of glacier volume and water resources.

  3. 1963 Vajont rock slide: a comparison between 3D DEM and 3D FEM

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni; Utili, Stefano; Castellanza, Riccardo; Agliardi, Federico; Bistacchi, Andrea; Weng Boon, Chia

    2013-04-01

    Data on the exact location of the failure surface of the landslide have been used as the starting point for the modelling of the landslide. 3 dimensional numerical analyses were run employing both the discrete element method (DEM) and a Finite Element Method (FEM) code. In this work the focus is on the prediction of the movement of the landlside during its initial phase of detachment from Mount Toc. The results obtained by the two methods are compared and conjectures on the observed discrepancies of the predictions between the two methods are formulated. In the DEM simulations the internal interaction of the sliding blocks and the expansion of the debris is obtained as a result of the kinematic interaction among the rock blocks resulting from the jointing of the rock mass involved in the slide. In the FEM analyses, the c-phi reduction technique was employed along the predefine failure surface until the onset of the landslide occurred. In particular, two major blocks of the landslide were identified and the stress, strain and displacement fields at the interface between the two blocks were analysed in detail.

  4. DEM generation from digital photographs using computer vision: Accuracy and application

    NASA Astrophysics Data System (ADS)

    James, M. R.; Robson, S.

    2012-12-01

    Data for detailed digital elevation models (DEMs) are usually collected by expensive laser-based techniques, or by photogrammetric methods that require expertise and specialist software. However, recent advances in computer vision research now permit 3D models to be automatically derived from unordered collections of photographs, and offer the potential for significantly cheaper and quicker DEM production. Here, we review the advantages and limitations of this approach and, using imagery of the summit craters of Piton de la Fournaise, compare the precisions obtained with those from formal close range photogrammetry. The surface reconstruction process is based on a combination of structure-from-motion and multi-view stereo algorithms (SfM-MVS). Using multiple photographs of a scene taken from different positions with a consumer-grade camera, dense point clouds (millions of points) can be derived. Processing is carried out by automated 'reconstruction pipeline' software downloadable from the internet. Unlike traditional photogrammetric approaches, the initial reconstruction process does not require the identification of any control points or initial camera calibration and is carried out with little or no operator intervention. However, such reconstructions are initially un-scaled and un-oriented so additional software has been developed to permit georeferencing. Although this step requires the presence of some control points or features within the scene, it does not have the relatively strict image acquisition and control requirements of traditional photogrammetry. For accuracy, and to allow error analysis, georeferencing observations are made within the image set, rather than requiring feature matching within the point cloud. Application of SfM-MVS is demonstrated using images taken from a microlight aircraft over the summit of Piton de la Fournaise volcano (courtesy of B. van Wyk de Vries). 133 images, collected with a Canon EOS D60 and 20 mm fixed focus lens, were used to create a ~1.6 km wide DEM covering the summit craters. When compared with a DEM constructed using close-range photogrammetry the SfM-MVS results showed an RMS error of 1.0 m. The overall precision of the project can be considered by ratioing this against the average viewing distance (1000 m). This relative precision of 1:1000 is in line with the results of other projects carried out over a range of spatial scales (down to ~0.1 m), so appears to be a characteristic expected achievable precision for the SfM-MVS approach. Consequently, over shorter viewing distances, absolute precisions increase - e.g. centimeter-level precisions for outcrop-scale studies where viewing distances may be expected to be of order 10 m. Although SfM-MVS cannot deliver the accuracy and precision of formal close-range photogrammetry, it can approach the results that are achievable from single stereo image pairs. However, the main advantages of the technique lie in the enhanced flexibility in image collection and automated processing, both of which significantly decrease the level of expertise required. When compared with terrestrial laser scanning at outcrop scales, the data collection time in the field can be reduced by ~80%. SfM-MVS data quality is sufficient for the technique to provide valuable DEMs of active flows and domes where access to (or for) modern surveying equipment is restricted.

  5. BOREAS HYD-8 DEM Data Over the NSA-MSA and SSA-MSA in the UTM Projection

    NASA Technical Reports Server (NTRS)

    Wang, Xue-Wen; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Band, L. E.; Smith, David E. (Technical Monitor)

    2000-01-01

    The BOREAS HYD-8 team focused on describing the scaling behavior of water and carbon flux processes at local and regional scales. These DEMs were produced from digitized contours at a cell resolution of 100 meters. Vector contours of the area were used as input to a software package that interpolates between contours to create a DEM representing the terrain surface. The vector contours had a contour interval of 25 feet. The data cover the BOREAS MSAs of the SSA and NSA and are given in a UTM map projection. Most of the elevation data from which the DEM was produced were collected in the 1970s or 1980s. The data are stored in binary, image format files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  6. Turbidity Current Transport using DEM and FEM: a Hybrid Lagrangian-Eulerian Approach

    NASA Astrophysics Data System (ADS)

    Alves, J. L.; Guevara, N. O., Jr.; Silva, C. E.; Alves, F. T.; Gazoni, L. C.; Coutinho, A.; Camata, J.; Elias, R. N.; Paraizo, P.

    2013-05-01

    In this work we describe a contribution to the study of turbidity transport in scales smaller than TFM (two-fluid models), The intent of the work, part of a large scale simulation project, is to assess local, small scale parameters and their upscaling. The hybrid model is based on a Lagrangian-Eulerian approach under a class of the so called Unresolved Discrete Particle Method (UDPM). In this approach, a Lagrangian description is used for the particle system employing the Discrete Element Method (DEM) while a fixed Eulerian mesh is used for the fluid phase modeled by finite element method (FEM), Fluid motion is governed by Navier-Stokes equations which are solved by an appropriate FEM implementation. Closure equation are used to compute drag and lift forces over the particles in the DEM framework. Volume averaged momentum sink terms are included in the fluid equations. The resulting coupled DEM-FEM model is integrated in time with a subcycling scheme. The aforementioned scheme was applied in the simulation of a sedimentation basin as depicted in figures 1 and 2 to investigate flow and deposition features of the suspension in a finer scale. For this purpose a submodel of the basin was generated. Mapping variables back and forth the Eulerian (finite element) model and the Lagrangian (discrete element) model were performed during the subcycled integration of the hybrid model. References: [1] Hoomans, B.P.B., Kuipers, J.A.M., Swaaij, van W.P.M," Granular dynamics Simulation of segregation phenomena in bubbling gas-fluidised beds", Powder Technology, V 109, Issues 1-3, 3 April 2000, pp 41-48; [2] Cho, S.H., Choi,H.G, Yoo, J.Y.,"Direct numerical simulation of fluid flow laden with many particles", International Journal of Multiphase Flow, V 31, Issue 4, April 2005, pp 435-451;; Sedimentation basin: sectioning the turbidity plume in the Eulerian FE model for setting up the discrete particle model. ; Sedimentation Basin: section of the turbidity plume displaying the generated discrete particle model underneath.

  7. Robust 3D Quantification of Glacial Landforms: A Use of Idealised Drumlins in a Real DEM

    NASA Astrophysics Data System (ADS)

    Hillier, J. K.; Smith, M. S.

    2012-04-01

    Drumlins' attributes, such as height (h) and volume (V ), may preserve important information about the dynamics of former ice sheets. However, measurement errors are large (e.g., 39.2% of V within ±25% of their real values for the 'cookie cutter') and, in general, poorly understood. To accurately quantify the morphology of glacial landforms, the relief belonging to that landform must be reliably isolated from other components of the landscape (e.g. buildings, hills). A number of techniques have been proposed for this regional-residual separation (RRS). Which is best? Justifications for those applied remain qualitative assertions. A recently developed, novel method using idealised drumlins of known size (hin, V in) in a real digital elevation model (DEM) is used to quantitatively determine the best RRS technique, allowing general guidelines for quantifying glacial landforms to be proposed. 184 drumlins with digitised outlines in western Central Scotland are used as a case study. The NEXTMap surface model (DSM) is the primary dataset employed. A variety of techniques are then investigated for their ability to recover sizes (hr, V r). A metric, ?, is used that maximises the number of Hr/Hin values near 1.0 whilst giving equal weight to different drumlin sizes: a metric dominated by the large number of small drumlins is not desirable. For simplicity, the semi-automated 'cookie cutter' technique is used as a baseline for comparison. This removes heights within a drumlin from a DEM, cuts a hole, then estimates its basal surface by interpolating across the space with a fully tensioned bi-cubic spline (-T1). Metrics for h and V are ?h = 0.885 and ?V = 0.247. Other tensions do not improve this significantly, with ?V of 0.245 at best, but using Delauney triangulation reduces ?V to 0.206. Windowed 'sliding median' filters, which do not require heights within drumlins to be removed, attain a minimum ?V of 0.470 at a best width of 340 m (-Fm340). Finally, even crudely (-Fm60) removing clutter (e.g. trees and buildings) to estimate a terrain model (DTM) before processing improves ?h dramatically to 0.412. Mean height (hin) of 6.8 m is then much better recovered at 7.1±0.3 (2?), as opposed to 12.5 ± 0.6 (2?) before decluttering. So, guidelines proposed to best quantify mapped glacial landforms are to i) declutter before ii) removing heights within the drumlin, then iii) interpolating to estimate a basal surface using Delauney triangulation. Mapping landforms' outlines from DTMs is not recommended since outlines are shifted by the distortions they contain, inducing errors. The 'synthetic' DEMs used have been demonstrated to be statistically valid, reliably representing reality. So, the optimal isolation method will now be used to assess the drumlins and their populations in the study area. Synthetic DEMs could be readily created to assess a variety of other landforms and other areas.

  8. Issues with using high-resolution DEMs for fluvial geomorphology modelling

    NASA Astrophysics Data System (ADS)

    Castro, Andres

    2015-04-01

    It is widely recognized that undertaking detailed fluvial morphology studies can be a difficult and expensive task due to the high amount of resources, such as time and highly trained personnel, that such studies requires in order to obtain accurate results. Yet, for a wide range of projects that in one way or another require the understanding fluvial systems, engineers are frequently challenged with the daunting task of managing expenses within tight budgets and expecting high quality results. It is with this perspective that it is often desired to simplify processes while maintaining a high reliability of results. In an attempt to tackle this issue the current PhD research presents an alternative methodology to undertake river geomorphology studies, by applying an automated procedure to model stream power from DEMs generated from high resolution LiDAR data. The main aim of the research is to estimate the stream power distribution along selected UK catchments and link the estimated stream power values to floodplain development processes. The raw LiDAR data, in the form of ASCII text files, used for the study correspond to 1m, 2m and 10m resolutions. During the process of creating the DEM of one of the selected rivers, the River Teme, the presence of a number of "blank spots" within the mosaic was noted. These areas corresponded to NoData zones generated presumably from the deflection of the laser beam on a water surface. Given that the GIS software didn't consider the missing data areas as part of the DEM, even though most of the "blank spots" were located on the river channel, it was necessary to develop a procedure in order to eliminate the NoData zones and correct the DEM, prior to undertaking the hydrological analysis of the catchment, without compromising the quality of the rest of the data. In search of an improved quality of results it has been commonly assumed that the higher resolution of the data the better and more accurate results are to be obtained. In the past much attention was focused on how to obtain and process the high resolution data. Nowadays with the availability of very high resolution spatial data and very powerful hardware it is becoming apparent that the quality and accuracy of results depends greatly of the software performance, as it has been found of the current research. While performing the hydrological analysis on GIS of the aforementioned selected UK rivers it was found that very high (1m or 2m) resolution LiDAR data does not provide of the most accurate representation of the rivers' flow paths. When compared with 10m resolution data it becomes apparent that the "lower" resolution data produces better results than the 1m or 2m data, more adjusted to the river actual path. It is possible to argue that the reason for this resides in limitations of the software itself. It is also necessary to point out that, while the for the current research purposes the 10m resolution data provides of better results, for other applications, such as topographic analyses of the area, very high resolution data (1m or 2m) is probably more adequate.

  9. Mechanistic Based DEM Simulation of Particle Attrition in a Jet Cup

    SciTech Connect

    Xu, Wei; DeCroix, David; Sun, Xin

    2014-02-01

    The attrition of particles is a major industrial concern in many fluidization systems as it can have undesired effects on the product quality and on the reliable operation of process equipment. Therefore, to accomodate the screening and selection of catalysts for a specific process in fluidized beds, risers, or cyclone applications, their attrition propensity is usually estimated through jet cup attrition testing, where the test material is subjected to high gas velocities in a jet cup. However, this method is far from perfect despite its popularity, largely due to its inconsistency in different testing set-ups. In order to better understand the jet cup testing results as well as their sensitivity to different operating conditions, a coupled computational fluid dynamic (CFD) - discrete element method (DEM) model has been developed in the current study to investigate the particle attrition in a jet cup and its dependence on various factors, e.g. jet velocity, initial particle size, particle density, and apparatus geometry.

  10. Quality of DEMs derived from Kite Aerial Photogrammety System: a case study of Dutch coastal environments.

    NASA Astrophysics Data System (ADS)

    Paron, Paolo; Smith, Mike J.; Anders, Niels; Meesuk, Vorawit

    2014-05-01

    Coastal protection is one of the main challenges for the Netherlands, where a large proportion of anthropogenic activity is located below sea level (both residential and economic). The Dutch government is implementing an innovative method of coastal replenishment using natural waves and winds to relocate sand from one side to the other of the country. This requires close monitoring of the spatio-temporal evolution of beaches in order to correctly model the future direction and amount of sand movement. To do so -on the onshore beach- we tested a Kite-Aerial Photography System for monitoring the beach dynamics at Zandmotor (http://www.dezandmotor.nl/en-GB/). The equipment used for data collection were a commercial DSLR camera (Nikon D7000 with a 20mm lens), gyro-levelled rig, Sutton Flowform 16 kite and Leica GNSS Viva GS10, with GSM connection to the Dutch geodetic network. We flew using a 115 m line with an average inclination of 40 to 45°; this gave a camera vertical distance of ~80 m and pixel size of ~20 mm. The methodology follows that of Smith et al. (2009), and of Paron & Smith (2013), applied to a highly dynamic environment with low texture and small relief conditions. Here we present a comparison of the quality of the digital elevation model (DEM) generated from the same dataset using two different systems: Structure from Motion (SfM) using Agisoft Photoscan Pro and traditional photogrammetry using Leica Photograpmmetry Suite. In addition the outputs from the two data processing methods are presented, including both an image mosaic and DEM, and highlighting pros and cons of both methods. References Smith, M. J. et al. 2009. High spatial resolution data acquisition for the geosciences: kite aerial photography. ESPL, 34(1), 155-161. Paron, P., Smith, M.J. 2013. Kite aerial photogrammetry system for monitoring coastal change in the Netherlands. 8th IAG International Conference on Geomorphology, Paris, August.

  11. Analysis of initial drainage network evolution from aerial photography and a DEM time series

    NASA Astrophysics Data System (ADS)

    Schneider, Anna; Gerke, Horst H.; Maurer, Thomas; Nenov, Rossen; Raab, Thomas

    2013-04-01

    The evolution of erosion rill or gully networks is a formative process in initial landscape development. Digital representations of drainage networks are often derived from Digital Elevation Models (DEMs) based on morphometric parameters, or mapped in field surveys or from aerial photographs. This study attempted to reconstruct and analyze the first five years of erosion rill network evolution in the 6 ha artificial catchment 'Hühnerwasser', which serves as a real world-laboratory to study patterns and processes of initial ecosystem development. The drainage network was characterized in a twofold approach, based on the analysis of remotely-sensed data. We used high-resolution drone-based aerial photographs to map the actively eroding rill network for four states of development, and a time series of ten Digital Elevation Models to characterize the morphology of the surface. Rill network maps and morphometric parameters were combined to allow for region-specific analyses of morphometry for different parts of the rill network. After a rapid growth of the erosion rill network during the first two years of development, a reduction of the area of actively eroding rills was observed. Region-specific analysis of morphometry indicates an increase in flow accumulation in the central parts of the rill network, which suggests that locally evolving feedback cycles between flow accumulation and erosion affected rill network development, in addition to the effects of precipitation characteristics and the growth of vegetation cover. The combination of drainage network characterization from aerial photography and DEMs could improve analyses of initial drainage network development in experimental studies, as it allows for critical comparisons of flow accumulation patterns and the actual patterns of erosion rills or gullies.

  12. Open-source MFIX-DEM software for gas-solids flows: Part I verification studies

    SciTech Connect

    Garg, Rahul; Galvin, Janine; Li, Tingwen; Pannala, Sreekanth

    2012-01-01

    With rapid advancements in computer hardware, it is now possible to perform large simulations of granular flows using the Discrete Element Method (DEM). As a result, solids are increasingly treated in a discrete Lagrangian fashion in the gas solids flow community. In this paper, the open-source MFIX-DEM software is described that can be used for simulating the gas solids flow using an Eulerian reference frame for the continuum fluid and a Lagrangian discrete framework (Discrete Element Method) for the particles. This method is referred to as the continuum discrete method (CDM) to clearly make a distinction between the ambiguity of using a Lagrangian or Eulerian reference for either continuum or discrete formulations. This freely available CDM code for gas solids flows can accelerate the research in computational gas solids flows and establish a baseline that can lead to better closures for the continuum modeling (or traditionally referred to as two fluid model) of gas solids flows. In this paper, a series of verification cases is employed which tests the different aspects of the code in a systematic fashion by exploring specific physics in gas solids flows before exercising the fully coupled solution on simple canonical problems. It is critical to have an extensively verified code as the physics is complex with highly-nonlinear coupling, and it is difficult to ascertain the accuracy of the results without rigorous verification. These series of verification tests set the stage not only for rigorous validation studies (performed in part II of this paper) but also serve as a procedure for testing any new developments that couple continuum and discrete formulations for gas solids flows.

  13. Open-source MFIX-DEM software for gas-solids flows: Part 1 - Verification studies

    SciTech Connect

    Garg, Rahul; Galvin, Janine; Li, Tingwen; Pannala, Sreekanth

    2012-04-01

    With rapid advancements in computer hardware, it is now possible to perform large simulations of granular flows using the Discrete Element Method (DEM). As a result, solids are increasingly treated in a discrete Lagrangian fashion in the gas–solids flow community. In this paper, the open-source MFIX-DEM software is described that can be used for simulating the gas–solids flow using an Eulerian reference frame for the continuum fluid and a Lagrangian discrete framework (Discrete Element Method) for the particles. This method is referred to as the continuum discrete method (CDM) to clearly make a distinction between the ambiguity of using a Lagrangian or Eulerian reference for either continuum or discrete formulations. This freely available CDM code for gas–solids flows can accelerate the research in computational gas–solids flows and establish a baseline that can lead to better closures for the continuum modeling (or traditionally referred to as two fluid model) of gas–solids flows. In this paper, a series of verification cases is employed which tests the different aspects of the code in a systematic fashion by exploring specific physics in gas–solids flows before exercising the fully coupled solution on simple canonical problems. It is critical to have an extensively verified code as the physics is complex with highly-nonlinear coupling, and it is difficult to ascertain the accuracy of the results without rigorous verification. These series of verification tests set the stage not only for rigorous validation studies (performed in part II of this paper) but also serve as a procedure for testing any new developments that couple continuum and discrete formulations for gas–solids flows.

  14. Open Source MFIX-DEM Software for Gas-Solids Flows: Part 1 - Verification Studies

    SciTech Connect

    Garg, Rahul; Galvin, Janine; Li, Tingwen; Pannala, Sreekanth

    2012-04-01

    With rapid advancements in computer hardware, it is now possible to perform large simulations of granular flows using the Discrete Element Method (DEM). As a result, solids are increasingly treated in a discrete Lagrangian fashion in the gas–solids flow community. In this paper, the open-source MFIX-DEM software is described that can be used for simulating the gas–solids flow using an Eulerian reference frame for the continuum fluid and a Lagrangian discrete framework (Discrete Element Method) for the particles. This method is referred to as the continuum discrete method (CDM) to clearly make a distinction between the ambiguity of using a Lagrangian or Eulerian reference for either continuum or discrete formulations. This freely available CDM code for gas–solids flows can accelerate the research in computational gas–solids flows and establish a baseline that can lead to better closures for the continuum modeling (or traditionally referred to as two fluid model) of gas–solids flows. In this paper, a series of verification cases is employed which tests the different aspects of the code in a systematic fashion by exploring specific physics in gas–solids flows before exercising the fully coupled solution on simple canonical problems. It is critical to have an extensively verified code as the physics is complex with highly-nonlinear coupling, and it is difficult to ascertain the accuracy of the results without rigorous verification. These series of verification tests set the stage not only for rigorous validation studies (performed in part II of this paper) but also serve as a procedure for testing any new developments that couple continuum and discrete formulations for gas–solids flows.

  15. DEM Simulated Results And Seismic Interpretation of the Red River Fault Displacements in Vietnam

    NASA Astrophysics Data System (ADS)

    Bui, H. T.; Yamada, Y.; Matsuoka, T.

    2005-12-01

    The Song Hong basin is the largest Tertiary sedimentary basin in Viet Nam. Its onset is approximately 32 Ma ago since the left-lateral displacement of the Red River Fault commenced. Many researches on structures, formation and tectonic evolution of the Song Hong basin have been carried out for a long time but there are still remained some problems that needed to put into continuous discussion such as: magnitude of the displacements, magnitude of movement along the faults, the time of tectonic inversion and right lateral displacement. Especially the mechanism of the Song Hong basin formation is still in controversy with many different hypotheses due to the activation of the Red River fault. In this paper PFC2D based on the Distinct Element Method (DEM) was used to simulate the development of the Red River fault system that controlled the development of the Song Hong basin from the onshore to the elongated portion offshore area. The numerical results show the different parts of the stress field such as compress field, non-stress field, pull-apart field of the dynamic mechanism along the Red River fault in the onshore area. This propagation to the offshore area is partitioned into two main branch faults that are corresponding to the Song Chay and Song Lo fault systems and said to restrain the east and west flanks of the Song Hong basin. The simulation of the Red River motion also showed well the left lateral displacement since its onset. Though it is the first time the DEM method was applied to study the deformation and geodynamic evolution of the Song Hong basin, the results showed reliably applied into the structural configuration evaluation of the Song Hong basin.

  16. A Progressive Black Top Hat Transformation Algorithm for Estimating Valley Volumes from DEM Data

    NASA Astrophysics Data System (ADS)

    Luo, W.; Pingel, T.; Heo, J.; Howard, A. D.

    2013-12-01

    The amount of valley incision and valley volume are important parameters in geomorphology and hydrology research, because they are related to the amount erosion (and thus the volume of sediments) and the amount of water needed to create the valley. This is not only the case for terrestrial research but also for planetary research as such figuring out how much water was on Mars. With readily available digital elevation model (DEM) data, the Black Top Hat (BTH) transformation, an image processing technique for extracting dark features on a variable background, has been applied to DEM data to extract valley depth and estimate valley volume. However, previous studies typically use one single structuring element size for extracting the valley feature and one single threshold value for removing noise, resulting in some finer features such as tributaries not being extracted and underestimation of valley volume. Inspired by similar algorithms used in LiDAR data analysis to separate above ground features and bare earth topography, here we propose a progressive BTH (PBTH) transformation algorithm, where the structuring elements size is progressively increased to extract valleys of different orders. In addition, a slope based threshold was introduced to automatically adjust the threshold values for structuring elements with different sizes. Connectivity and shape parameters of the masked regions were used to keep the long linear valleys while removing other smaller non-connected regions. Preliminary application of the PBTH to Grand Canyon and two sites on Mars has produced promising results. More testing and fine-tuning is in progress. The ultimate goal of the project is to apply the algorithm to estimate the volume of valley networks on Mars and the volume of water needed to form the valleys we observe today and thus infer the nature of the hydrologic cycle on early Mars. The project is funded by NASA's Mars Data Analysis program.

  17. Comparison of SIFT and SURF based DEM extraction approaches on a GEOEYE-1 satellite stereo-pair

    NASA Astrophysics Data System (ADS)

    Daliakopoulos, Ioannis; Tsanis, Ioannis

    2014-05-01

    A MATLAB module for Digital Elevation Model (DEM) extraction from Very High Resolution (VHR) satellite stereo-pair imagery is used to compare the efficiency of two well established feature detection and description algorithms. A procedure for parallel processing of cascading image tiles is used for handling the large datasets requirements of VHR satellite imagery. Scale-Invariant Feature Transform (SIFT) and Speeded Up Robust Features (SURF) algorithms are used to detect potentially tentative feature matches in the members of the stereo-pair. The resulting feature pairs are filtered using the RANdom SAmple Consensus (RANSAC) algorithm by using a variable distance threshold. Finally, tentative feature matches are converted to point cloud ground coordinates for DEM generation. A 0.5 m × 0.5 m Geoeye-1 stereo-pair acquired over an area of 25 km2 in the island of Crete, Greece is used as input for the module. The resulting 2 m × 2 m DEMs has superior detail over previously developed 2 m and 5 m DEMs that are used as reference, and yields a Root Mean Square Error (RMSE) of about 1 m compared to ground truth measurements. Results suggest that SURF's superior runtime performance outweighs the slightly better feature quality attained with SIFT.

  18. Nr. 111 / 2014 // 17. Juni 2014 Die Teilnehmerinnen und Teilnehmer der diesjhrigen EASM Summer School vor dem Firmen-

    E-print Network

    Schittkowski, Klaus

    School vor dem Firmen- gebäude der Puma AG in Herzogenaurach. Attraktive Berufsperspektiven im internationalen Sportmanagement Die EASM Summer School zu Gast bei der Puma AG in Herzogenaurach Vor kurzem war Tschechien und aus Deutschland beim Sportartikelhersteller Puma in Herzogenaurach eingeladen. Hier erhielten

  19. DEM-based reconstruction of southern Basse-Terre volcanoes (Guadeloupe archipelago, FWI): Contribution to the Lesser Antilles Arc construction

    E-print Network

    by the reconstruction of a volcano's morphology and time sequences. However, composite volcanoes often have complex. In this paper we present 3D reconstructions of a range of composite volcanoes, the overall activity of whichDEM-based reconstruction of southern Basse-Terre volcanoes (Guadeloupe archipelago, FWI

  20. Ice dynamics of Himalayan glaciers (Himachal Pradesh, India) using TerraSAR-X/TanDEM-X data.

    NASA Astrophysics Data System (ADS)

    Vijay, Saurabh; Braun, Matthias

    2015-04-01

    Mountain glaciers are the natural indicators of climate change. Himalaya is a part of widely spread mountain range consisting of second largest ice mass after polar region. The glaciers in Himalaya are located in Himachal Pradesh and other territories of India. The precipitation in the region is influenced by both Indian summer monsoon and mid-latitude winter westerlies. The glacier discharge influences the river basins and provides fresh water for various infrastructural necessities of urbanization in the state. The study aims to estimate the ice thickness and volume change during the decade (2011-2000) and annually during 2011-2014. For this, TanDEM-X DEMs are subtracted from the SRTM C/X band DEM of 2000. In addition, ice flow dynamics are quantified by the constellation of TerraSAR-X/TanDEM-X data using SAR offset tracking method. The primary investigations reveal that the terminus velocity of Bada Shigri (G077683E32169N), the biggest glacier of the state, Chhota Shigri( G077513E32227N), a bench-mark glacier, and other glacier (G077547E32162N) in 2011 found out to be < 2cm/day. The upper stream velocities of the glaciers are increased linearly and influenced by glacier tributaries.

  1. BOREAS HYP-8 DEM Data Over The NSA-MSA and SSA-MSA in The AEAC Projection

    NASA Technical Reports Server (NTRS)

    Knapp, David E.; Hall, Forrest G. (Editor); Wang, Xue-Wen; Band, L. E.; Smith, David E. (Technical Monitor)

    2000-01-01

    These data were derived from the original Digital Elevation Models (DEMs) produced by the Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-8 team. The original DEMs were in the Universal Transverse Mercator (UTM) projection, while this product is projected in the Albers Equal-Area Conic (AEAC) projection. The pixel size of the data is 100 meters, which is appropriate for the 1:50,000-scale contours from which the DEMs were made. The original data were compiled from information available in the 1970s and 1980s. This data set covers the two Modeling Sub-Areas (MSAs) that are contained within the Southern Study Area (SSA) and the Northern Study Area (NSA). The data are stored in binary, image format files. The DEM data over the NSA-MSA and SSA-MSA in the AEAC projection are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  2. Mapping hydrological environments in central Amazonia: ground validation and surface model based on SRTM DEM data corrected for deforestation

    NASA Astrophysics Data System (ADS)

    Moulatlet, G. M.; Rennó, C. D.; Costa, F. R. C.; Emilio, T.; Schietti, J.

    2014-07-01

    One of the most important freely available digital elevation models (DEMs) for Amazonia is the one obtained by the Shuttle Radar Topography Mission (SRTM). However, since SRTM tends to represent the vegetation surface instead of the ground surface, the broad use of SRTM DEM as a framework for terrain description in Amazonia is hampered by the presence of deforested areas. We present here two datasets: (1) a deforestation-corrected SRTM DEM for the interfluve between the Purus and Madeira rivers, in central Amazonia, which passed through a careful identification of different environments and has deforestation features corrected by a new method of increasing pixel values of the DEM; and (2) a set of eighteen hydrological-topographic descriptors based on the corrected SRTM DEM. The hydrological-topographic description was generated by the Height Above the Nearest Drainage (HAND) algorithm, which normalizes the terrain elevation (a.s.l.) by the elevation of the nearest hydrologically connected drainage. The validation of the HAND dataset was done by in situ hydrological description of 110 km of walking trails also available in this dataset. The new SRTM DEM expands the applicability of SRTM data for landscape modelling; and the datasets of hydrological features based on topographic modelling is undoubtedly appropriate for ecological modelling and an important contribution for environmental mapping of Amazonia. The deforestation-corrected SRTM DEM is available at http://ppbio.inpa.gov.br/knb/metacat/naman.318.3/ppbio; the polygons selected for deforestation correction are available at http://ppbio.inpa.gov.br/knb/metacat/naman.317.3/ppbio; the set of hydrological-topographic descriptors is available at http://ppbio.inpa.gov.br/knb/metacat/naman.544.2/ppbio; and the environmental description of access trails is available at http://ppbio.inpa.gov.br/knb/metacat/naman.541.2/ppbio.

  3. EarthEnv-DEM90: A nearly-global, void-free, multi-scale smoothed, 90m digital elevation model from fused ASTER and SRTM data

    NASA Astrophysics Data System (ADS)

    Robinson, Natalie; Regetz, James; Guralnick, Robert P.

    2014-01-01

    A variety of DEM products are available to the public at no cost, though all are characterized by trade-offs in spatial coverage, data resolution, and quality. The absence of a high-resolution, high-quality, well-described and vetted, free, global consensus product was the impetus for the creation of a new DEM product described here, 'EarthEnv-DEM90'. This new DEM is a compilation dataset constructed via rigorous techniques by which ASTER GDEM2 and CGIAR-CSI v4.1 products were fused into a quality-enhanced, consistent grid of elevation estimates that spans ?91% of the globe. EarthEnv-DEM90 was assembled using methods for seamlessly merging input datasets, thoroughly filling voids, and smoothing data irregularities (e.g. those caused by DEM noise) from the approximated surface. The result is a DEM product in which elevational artifacts are strongly mitigated from the input data fusion zone, substantial voids are filled in the northern-most regions of the globe, and the entire DEM exhibits reduced terrain noise. As important as the final product is a well defined methodology, along with new processing techniques and careful attention to final outputs, that extends the value and usability of the work beyond just this single product. Finally, we outline EarthEnv-DEM90 acquisition instructions and metadata availability, so that researchers can obtain this high-resolution, high-quality, nearly-global new DEM product for the study of wide-ranging global phenomena.

  4. Characterization of active fault scarps from medium to high resolution DEM: case studies from Central and Southern Apennines (Italy)

    NASA Astrophysics Data System (ADS)

    Brunori, C.; Cinti, F. R.; Ventura, G.

    2013-12-01

    We identify geo-morphometric features of active fault scarps in Italy through a semiautomatic processing using GIS. Medium to high resolution DEM was used to characterize the geometry, structural, and erosive elements of two seismogenic normal faults in Central and Southern Apennines. The Pettino fault in L'Aquila area was detected using a 1 m pixel DEM derived from airborne LiDAR survey (Friuli Venezia Giulia Civil Protection). For the Castrovillari fault in northern Calabria region was used a 4 m pixel DEM (Regional Cartography Office of Regione Calabria). Scarp segments are region of planar discontinuities identified by selected values of DEM-derived Terrain Ruggedness Index (TRI) and Vector Ruggedness Measure (VRM). These planar discontinuities corresponds to landscape features such as, river terraces, roads scarps, and other natural or human features. The discrimination between these features have been accomplished overlaying extracted features on aerial photograph, geological and geomorphologic maps and in situ survey. After that, we perform the quantitative and statistical analysis of these areas identified as "fault scarps". The identification of elements relative to the scarps (e.g. base, crest, slope) is then obtained to derive the estimate of parameters describing the fault: altitude, height of the scarp, length, slope and aspect, Terrain Ruggedness Index (TRI) and Vector Ruggedness Measure (VRM). The spatial distribution of the extracted values was obtained through their statistical analysis. We analyze scarp parameters variations along the whole scarp extent, such as strike value from aspect variations, slope and profile curvature differences as indicators of tectonic and/or erosion activity. The combined analysis of the DEM-derived parameters allows us to (a) define aspects of three-dimensional scarp geometry, (b) decipher its geomorphological significance, and (c) estimate the long-term slip rate.

  5. Constructing a Comprehensive Tool for Deriving Drainage Network using Semi-Open Source Tools and Comparision on Different DEM Data Sources

    NASA Astrophysics Data System (ADS)

    Gupta, P. K.; Yadav, P.

    2014-11-01

    Digital elevation model (DEM) provides elevation information in raster format for an area which help in analysis as these phenomena are gravity depended. Hydrological study requires creation of drainage network map. DEM is the primary input for this process. Generally 6 or more processes are required to be completed to get the drainage network. These are available in form of hydrology tools in the ArcGIS software. These processes are manual and time consuming which increases the chances of human error. An automated process is constructed in this paper which aims to create a tool that can handle multiple files in an intelligent manner. The input DEM plays a significant role in hydrological studies. This study attempts to do a comparative study to analyse the variation in the drainage network and the intermediate products with the change in the input DEM. A tool is created using ArcPy site package in Python programming language to integrate all required hydrology tools. The script is then used to create a tool in ArcGIS 10 which takes location as an input parameter and perform the process on all the DEM files inside the directory. The tool creates separate directory for every DEM file and thus reduces the chances of file mismanagement. The proposed tool is tested on two different datasets namely ASTER GDEM and Cartosat DEM. The tool runs efficiently on both the datasets and thus provides results to compare the drainage pattern produced by these different data sources.

  6. Toward a simple, DEM-based model for linking channel morphology with Atlantic salmon habitat

    NASA Astrophysics Data System (ADS)

    Snyder, N. P.; Wilkins, B. C.; Wright, J. R.

    2008-12-01

    Atlantic salmon require swiftwater gravel-bedded rivers for rearing and spawning. Morphology of the rivers in coastal New England and Atlantic Canada is strongly influenced by glacial and land-use history. Longitudinal profiles are characterized by relatively steep (gradient >0.002) and flat (gradient <0.0005) segments, with length scales of several km. This heterogeneity corresponds to strong variations in channel form (boulder cascades, pools and riffles, plane beds, low-gradient wetlands, mainstem lakes), substrate grain size, and aquatic habitat characteristics. We seek to develop methods to use simple GIS-based measurements to investigate relationships between channel processes and habitat characteristics. The near extirpation of Atlantic salmon from U.S. rivers motivates restoration efforts, including the removal of barriers to migration and instream habitat restoration projects. Resource managers desire GIS-based methods to facilitate rapid identification of potential spawning and rearing habitat within channel networks. We develop methods for predicting channel conditions using traditional (10-30 m pixels) and lidar (1-m pixels) digital elevation models (DEMs). We calibrate and test our methods using field surveys of habitat, channel form and bed grain size in coastal Maine and New Brunswick. A statistical approach uses stream gradient measured over segments defined by channel centerline intersections with contour lines (3-6 m intervals) on digitized topographic maps, contributing area, and physiographic province. This model explains 73% of the variation in field-identified rearing habitat. Commonly available GIS data allows this model to be applied over large areas, making it useful for regional habitat assessments. We present preliminary results from a process- based model that predicts bed grain size using morphologic measurements from lidar DEMs and the Shields equation. We compare these predictions to field grain size and habitat mapping. The lidar-based method has similar predictive capability to the statistical model, and greater spatial resolution (channel gradient is measured over 0.5-m vertical intervals). We suggest that failures in the lidar-based approach likely relate to local variations in channel roughness and sediment size and supply not included in the model. Further, we speculate that these mismatches may present an opportunity to prioritize stream restoration efforts such as removal of small dams or additions of large woody debris by identifying river reaches with potential high- quality habitat.

  7. Satellite-derived Digital Elevation Model (DEM) selection, preparation and correction for hydrodynamic modelling in large, low-gradient and data-sparse catchments

    NASA Astrophysics Data System (ADS)

    Jarihani, Abdollah A.; Callow, John N.; McVicar, Tim R.; Van Niel, Thomas G.; Larsen, Joshua R.

    2015-05-01

    Digital Elevation Models (DEMs) that accurately replicate both landscape form and processes are critical to support modelling of environmental processes. Topographic accuracy, methods of preparation and grid size are all important for hydrodynamic models to efficiently replicate flow processes. In remote and data-scarce regions, high resolution DEMs are often not available and therefore it is necessary to evaluate lower resolution data such as the Shuttle Radar Topography Mission (SRTM) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) for use within hydrodynamic models. This paper does this in three ways: (i) assessing point accuracy and geometric co-registration error of the original DEMs; (ii) quantifying the effects of DEM preparation methods (vegetation smoothed and hydrologically-corrected) on hydrodynamic modelling relative accuracy; and (iii) quantifying the effect of the hydrodynamic model grid size (30-2000 m) and the associated relative computational costs (run time) on relative accuracy in model outputs. We initially evaluated the accuracy of the original SRTM (?30 m) seamless C-band DEM (SRTM DEM) and second generation products from the ASTER (ASTER GDEM) against registered survey marks and altimetry data points from the Ice, Cloud, and land Elevation Satellite (ICESat). SRTM DEM (RMSE = 3.25 m,) had higher accuracy than ASTER GDEM (RMSE = 7.43 m). Based on these results, the original version of SRTM DEM, the ASTER GDEM along with vegetation smoothed and hydrologically corrected versions were prepared and used to simulate three flood events along a 200 km stretch of the low-gradient Thompson River, in arid Australia (using five metrics: peak discharge, peak height, travel time, terminal water storage and flood extent). The hydrologically corrected DEMs performed best across these metrics in simulating floods compared with vegetation smoothed DEMs and original DEMs. The response of model performance to grid size was non-linear and while the smaller grid sizes (?120 m) improved the hydrodynamic model results, these offered only slight improvements at very significant computational costs compared to grid size of 120 m, with grid sizes 250 m and greater decreasing in model accuracy. This study highlights the important impact that the quality of the underlying DEM has, and in particular how sensitive hydrodynamic models are to preparation methods and how important vegetation smoothing and hydrological correction of the base topographic data for modelling floods in low-gradient and multi-channel environments.

  8. CFD-DEM study of effect of bed thickness for bubbling fluidized beds

    SciTech Connect

    Tingwen, Li; Gopalakrishnan, Pradeep; Garg, Rahul; Shahnam, Mehrdad

    2011-10-01

    The effect of bed thickness in rectangular fluidized beds is investigated through the CFD–DEM simulations of small-scale systems. Numerical results are compared for bubbling fluidized beds of various bed thicknesses with respect to particle packing, bed expansion, bubble behavior, solids velocities, and particle kinetic energy. Good two-dimensional (2D) flow behavior is observed in the bed having a thickness of up to 20 particle diameters. However, a strong three-dimensional (3D) flow behavior is observed in beds with a thickness of 40 particle diameters, indicating the transition from 2D flow to 3D flow within the range of 20–40 particle diameters. Comparison of velocity profiles near the walls and at the center of the bed shows significant impact of the front and back walls on the flow hydrodynamics of pseudo-2D fluidized beds. Hence, for quantitative comparison with experiments in pseudo-2D columns, the effect of walls has to be accounted for in numerical simulations.

  9. Synthesizing maps of 3D scenes from multiple reference views without constructing the DEM

    NASA Astrophysics Data System (ADS)

    Barrett, Eamon B.; Payton, Paul M.; Marra, Peter J.

    1996-12-01

    The reference data consists of two or more central- projection images of a three-dimensional distribution of object points, i.e., a 3D scene. The positions and orientations of the cameras which generated the reference images are unknown, as are the coordinates of all the object points. We derive and demonstrate invariant methods for synthesizing nadir views of the object points, i.e., 2D maps of the 3D scene. The techniques we demonstrate depart from standard methods of resection and intersection to recover the camera geometry and reconstruct object points from the reference images, followed by back-projection to create the nadir view. Our approach will be to perform the image measurements and computations required to estimate the image invariant relationships linking the reference images to one another and to the nadir view. The empirically estimated invariant relationships can thereafter be used to transfer conjugate points from the reference images to their synthesized conjugates in the nadir view. Computation of the object model -- the digital elevation model (DEM) -- is not required in this approach. The method also differs from interpolation in that the 3D structure of the scene is preserved, including the effects of partial occlusion. Algorithms are validated, initially with synthetic CAD models and subsequently with real data consisting of uncontrolled aerial imagery and maps with occasional missing or inaccurately delineated features.

  10. Transformation (normalization) of slope gradient and surface curvatures, automated for statistical analyses from DEMs

    NASA Astrophysics Data System (ADS)

    Csillik, O.; Evans, I. S.; Dr?gu?, L.

    2015-03-01

    Automated procedures are developed to alleviate long tails in frequency distributions of morphometric variables. They minimize the skewness of slope gradient frequency distributions, and modify the kurtosis of profile and plan curvature distributions toward that of the Gaussian (normal) model. Box-Cox (for slope) and arctangent (for curvature) transformations are tested on nine digital elevation models (DEMs) of varying origin and resolution, and different landscapes, and shown to be effective. Resulting histograms are illustrated and show considerable improvements over those for previously recommended slope transformations (sine, square root of sine, and logarithm of tangent). Unlike previous approaches, the proposed method evaluates the frequency distribution of slope gradient values in a given area and applies the most appropriate transform if required. Sensitivity of the arctangent transformation is tested, showing that Gaussian-kurtosis transformations are acceptable also in terms of histogram shape. Cube root transformations of curvatures produced bimodal histograms. The transforms are applicable to morphometric variables and many others with skewed or long-tailed distributions. By avoiding long tails and outliers, they permit parametric statistics such as correlation, regression and principal component analyses to be applied, with greater confidence that requirements for linearity, additivity and even scatter of residuals (constancy of error variance) are likely to be met. It is suggested that such transformations should be routinely applied in all parametric analyses of long-tailed variables. Our Box-Cox and curvature automated transformations are based on a Python script, implemented as an easy-to-use script tool in ArcGIS.

  11. Astronomical solar radiation simulation based on DEM in Wuyishan mountainous areas

    NASA Astrophysics Data System (ADS)

    Wang, Shaogang; He, Guojin; Liu, Dingsheng; Wang, Xiaoqin

    2008-12-01

    Digital Elevation Models (DEM) data (90mx90m) reflected by the NASA Shuttle Radar Topography Mission (SRTM) are used as basic information source to overlay digital slope models and digital aspect models, which are applicable to the mountainous terrain of astronomical solar radiation distributed model. This paper uses ray-tracing method and integral by subparagraph to calculate the conditions of terrain shading information, and through an integral way to make a visualization of monthly astronomical solar radiation (ASR). The result shows that the geographical and topographical factors do visible effect to the spatial distribution of astronomical solar radiation over Wuyishan area, especially in January, it does the most obvious effect to terrain shading, while in July it does the lightest effect to terrain shading. This method can accurately reflect regional differences of solar radiation, and through accumulating daily solar radiation in the region, we can obtain the total amount of solar radiation in every month of the year. This result can provide prerequisite conditions as an important reference and then be useful to biomass estimating of vegetation, agricultural production, climatic resources development and exploiture.

  12. Production of Optimized DEM Using IDW Interpolation Method (Case Study; Jam and Riz Basin-Assaloyeh)

    NASA Astrophysics Data System (ADS)

    Soleimani, K.; Modallaldoust, S.

    In this research, preparing the optimized Digital Elevation Model (DEM)of Jam and Riz basin was studied by use of Inverse Distance Weighting (IDW) and utilization of GIS technique. Performing of IDW method depends on several factors including cell size, number of neighbor`s points, point searching radius and optimized power. On this basis, two Geostatistical methods were used for determination of points searching radius of standard ellipse and standard deviation ellipse. Considering the fixed cell size in network with value of 3 which represents weighting degree of points and with determining the rotation angle and measure of axis of standard deviation ellipse and calculation of optimized radius in standard ellipse by use of statistical method, then optimized power was automatically derived in ArcGIS 9.2 environment. In this method the number of neighbor's points was selected with four repetition points of 3, 5, 7 and 15. However, 8 digital elevation models were gained after the mentioned processes. Finally, digital elevation models of 1 to 8 were compared with control points using compare means test in SPSS11.5 statistical software which shown the IDW-3 with the best conditions recommended as the optimized model. Although the results are showing a similar forms but from them IDW3 model has the lowest mean standard error of 0.26842 which is used seven neighbor points.

  13. Numerical modelling by the Stokes--DEM coupled simulation for a roof at hot magma chamber

    NASA Astrophysics Data System (ADS)

    Furuichi, M.; Nishiura, D.

    2014-12-01

    The dynamics of a granular media has been suggested to play an important role in a reheated magma chamber by a hot intrusion (e.g. Burgisser and Bergantz, 2011). Although several mechanisms, such as Rayleigh Taylor instability, unzipping, and rhythmic convection (e.g. Shibano et.al. 2012, 2013), have been proposed for characterizing upward migration process in a crystalline magma chamber, their contributions in the long geodynamical time scale are not clear yet. Thus we perform numerical simulations to investigate the thermal evolution of the magma chamber with basal intrusion in three dimensions. In order to solve high-viscosity fluid and particle dynamics for modelling a melt--crystal jammed state of the magma, we have developed a coupled Stokes--DEM simulation code with two key techniques: formulation of particle motion without inertia and semi-implicit treatment of particle motion in the fluid equation (Furuichi and Nishiura 2014). Our simulation can successfully handle sinking particles in a high-viscosity fluid. We examine different types of the granular media heated from the bottom with varying parameters. We especially focus on pattern of the settling particles against the melt density contrast between upper and lower region.

  14. New insights into high resolution DEM structural analysis with Coltop3D software

    NASA Astrophysics Data System (ADS)

    Metzger, R.; Jaboyedoff, M.; Oppikofer, T.

    2009-04-01

    Modern measurement devices such a terrestrial laser scanning (TLS) systems allow for collecting tremendous amount of (x,y,z) points (up to 20 millions) within a few minutes. However, data analysis still may be impaired because of software limitations, which are usually not designed to handle such huge data sets. To overcome this shortcoming, a software - Coltop3D - was written from scratch. Coltop3D aims at providing the geosciences community a powerful tool to visually handle seamlessly large point clouds and large regular grids DEM, at allowing for straightforward visual analysis of the data with different colour scheme, and at providing specific geologist and/or geoscientist treatment methods such as structural analysis. The main features of Coltop3D are as follow: 1) Ability to handle huge data sets (up to 150 millions points); 2) Coloring the surface with a color scheme linking computer graphics HSV wheel and Schmidt-Lambert stereonet projection; 3) Ability to select a subset of a point cloud with complex geometric shapes; 4) Ability to select a subset of a point cloud with dip and dip direction values; 5) Creating density stereonets with selected subset; 6) Easily import from or export point cloud data to third party software. Besides the technical and basic capabilities of Coltop3D, specific case studies such as structural analysis and rock fall analysis will be presented.

  15. DEM simulation of particle mixing for optimizing the overcoating drum in HTR fuel fabrication

    NASA Astrophysics Data System (ADS)

    Liu, Malin; Lu, Zhengming; Liu, Bing; Shao, Youlin

    2013-06-01

    The rotating drum was used for overcoating coated fuel particles in HTR fuel fabrication process. All the coated particles should be adhered to equal amount of graphite powder, which means that the particle should be mixed quickly in both radial and axial directions. This paper investigated the particle flow dynamics and mixing behavior in different regimes using the discrete element method (DEM). By varying the rotation speed, different flow regimes such as slumping, rolling, cascading, cataracting, centrifuging were produced. The mixing entropy based on radial and axial grid was introduced to describe the radial and axial mixing behaviors. From simulation results, it was found that the radial mixing can be achieved in the cascading regime more quickly than the slumping, rolling and centrifuging regimes, but the traditional rotating drum without internal components can not achieve the requirements of axial mixing and should be improved. Three different structures of internal components are proposed and simulated. The new V-shaped deflectors were found to achieve a quick axial mixing behavior and uniform axial distribution in the rotating drum based on simulation results. At last, the superiority was validated by experimental results, and the new V-shaped deflectors were used in the industrial production of the overcoating coated fuel particles in HTR fuel fabrication process.

  16. Constructing a prior information base for river mapping from digital images and DEMs by an advanced image interpretation system

    NASA Astrophysics Data System (ADS)

    Demirkesen, Ali Can

    The purpose of this dissertation is to describe the construction of a prior information-base (interpretation of river characteristics) for river mapping from digital representations, such as remotely sensed digital images and DEMs, by an advanced image interpretation system. More reliable prior information availability in an advanced image interpretation system enables GIS and remote sensing facilities to locate rivers in an easier, more accurate and more straightforward way. In this study, the author proposes a prior information-base including some rules and facts for river mapping from the use of both remotely sensed multi-spectral images and DEMs. These rules not only allow water-related applications in both GIS and remote sensing to be more accurate, but also construct the information-base for river mapping by an advanced image interpretation system. These rules were constructed as a synthesis from searching the literature and experiments with both digital images and DEMs. These rules are employed in an advanced image interpretation system which requires (1) a prior information-base; (2) a working memory; (3) an inference module (Caelli and Bischof, 1997; Schenk and Zilberstein, 1990). A prior information-base is formed by a set of rules (qualitative or quantitative or relationships). A working memory has the basic function of holding features in the form of spatial data and their attribute values. These spatial and attribute data are used by interpreters to activate the rules. Inference module refers to software and hardware that connect the user's questions to the prior information-base and instruct the user (interpreter) about the process. In this dissertation, a prior information-based river mapping was implemented and the proposed rules were tested studying both images and DEMs in IDRISI, as well as RiverTools.

  17. Direct micromechanics derivation and DEM confirmation of the elastic moduli of isotropic particulate materials: Part I No particle rotation

    NASA Astrophysics Data System (ADS)

    Fleischmann, J. A.; Drugan, W. J.; Plesha, M. E.

    2013-07-01

    We derive the macroscopic elastic moduli of a statistically isotropic particulate aggregate material via the homogenization methods of Voigt (1928) (kinematic hypothesis), Reuss (1929) (static hypothesis), and Hershey (1954) and Kröner (1958) (self-consistent hypothesis), originally developed to treat crystalline materials, from the directionally averaged elastic moduli of three regular cubic packings of uniform spheres. We determine analytical expressions for these macroscopic elastic moduli in terms of the (linearized) elastic inter-particle contact stiffnesses on the microscale under the three homogenization assumptions for the three cubic packings (simple, body-centered, and face-centered), assuming no particle rotation. To test these results and those in the literature, we perform numerical simulations using the discrete element method (DEM) to measure the overall elastic moduli of large samples of randomly packed uniform spheres with constant normal and tangential contact stiffnesses (linear spring model). The beauty of DEM is that simulations can be run with particle rotation either prohibited or unrestrained. In this first part of our two-part series of papers, we perform DEM simulations with particle rotation prohibited, and we compare these results with our theoretical results that assumed no particle rotation. We show that the self-consistent homogenization assumption applied to the locally body-centered cubic (BCC) packing most accurately predicts the measured values of the overall elastic moduli obtained from the DEM simulations, in particular Poisson's ratio. Our new analytical self-consistent results lead to significantly better predictions of Poisson's ratio than all prior published theoretical results. Moreover, our results are based on a direct micromechanics analysis of specific geometrical packings of uniform spheres, in contrast to all prior theoretical analyses, which were based on difficult-to-verify hypotheses involving overall inter-particle contact distributions. We continue the analysis begun in this first part for the case of unrestrained particle rotation in Part II, Fleischmann et al. (2013).

  18. A Screening Method for Flash Flooding Risk using Instantaneous Unit Hydrographs Derived from High Resolution DEM data

    NASA Astrophysics Data System (ADS)

    Senevirathne, Nalin; Willgoose, Garry

    2015-04-01

    Flash flooding is considered a severe natural hazard and has had significant impact on human and infrastructure throughout the history. Modelling techniques and the understanding of flash flooding are getting improved with the availability of better quality data such as high resolution Digital Elevation Models (DEM). DEMs allow the automated characterization of the influence of geomorphology on the hydrologic response of catchments. They are particularly useful for small ungauged catchments where available hydrologic data (e.g. rainfall, runoff) are sparse and where site specific studies are rarely done unless some evidence of high risk is available. In this paper, we present new risk indicators, derived directly from instantaneous unit hydrographs (IUH), which can be used to identify flash flooding risk areas within catchments. The study area includes 35 major river basins covering a 1700km long by 50km wide coastal strip of Eastern Australia. Standard terrain analysis methods (pit filling, flow direction, local slope, contributing area, flow velocity and travel time) were used to produce IUHs for every pixel in the study area using a high resolution (1 arc second) DEM. When computing the IUHs, each pixel was considered as the outlet of its own catchment bounded by its contributing area. This allows us to characterise the hydrological response at the finest scale possible for a DEM. Risk indicators related to rate of storm rise and catchment lag time were derived from IUHs. Flash flood risk maps were produced at the catchment scale and they are match well with the data of severe flash flooding that occurred around Toowoomba (at the northern end of the coastal strip studied) in January 2011.

  19. GIS-based debris flow source and runout susceptibility assessment from DEM data - a case study in NW Nicaragua

    NASA Astrophysics Data System (ADS)

    Guinau, M.; Vilajosana, I.; Vilaplana, J. M.

    2007-11-01

    In October 1998, Hurricane Mitch triggered numerous landslides (mainly debris flows) in Honduras and Nicaragua, resulting in a high death toll and in considerable damage to property. The potential application of relatively simple and affordable spatial prediction models for landslide hazard mapping in developing countries was studied. Our attention was focused on a region in NW Nicaragua, one of the most severely hit places during the Mitch event. A landslide map was obtained at 1:10 000 scale in a Geographic Information System (GIS) environment from the interpretation of aerial photographs and detailed field work. In this map the terrain failure zones were distinguished from the areas within the reach of the mobilized materials. A Digital Elevation Model (DEM) with 20 m×20 m of pixel size was also employed in the study area. A comparative analysis of the terrain failures caused by Hurricane Mitch and a selection of 4 terrain factors extracted from the DEM which, contributed to the terrain instability, was carried out. Land propensity to failure was determined with the aid of a bivariate analysis and GIS tools in a terrain failure susceptibility map. In order to estimate the areas that could be affected by the path or deposition of the mobilized materials, we considered the fact that under intense rainfall events debris flows tend to travel long distances following the maximum slope and merging with the drainage network. Using the TauDEM extension for ArcGIS software we generated automatically flow lines following the maximum slope in the DEM starting from the areas prone to failure in the terrain failure susceptibility map. The areas crossed by the flow lines from each terrain failure susceptibility class correspond to the runout susceptibility classes represented in a runout susceptibility map. The study of terrain failure and runout susceptibility enabled us to obtain a spatial prediction for landslides, which could contribute to landslide risk mitigation.

  20. Precise Determination of the Baseline Between the TerraSAR-X and TanDEM-X Satellites

    NASA Astrophysics Data System (ADS)

    Koenig, Rolf; Rothacher, Markus; Michalak, Grzegorz; Moon, Yongjin

    TerraSAR-X, launched on June 15, 2007, and TanDEM-X, to be launched in September 2009, both carry the Tracking, Occultation and Ranging (TOR) category A payload instrument package. The TOR consists of a high-precision dual-frequency GPS receiver, called Integrated GPS Occultation Receiver (IGOR), for precise orbit determination and atmospheric sounding and a Laser retro-reflector (LRR) serving as target for the global Satellite Laser Ranging (SLR) ground station network. The TOR is supplied by the GeoForschungsZentrum Potsdam (GFZ) Germany, and the Center for Space Research (CSR), Austin, Texas. The objective of the German/US collaboration is twofold: provision of atmospheric profiles for use in numerical weather predictions and climate studies from the occultation data and precision SAR data processing based on precise orbits and atmospheric products. For the scientific objectives of the TanDEM- X mission, i.e., bi-static SAR together with TerraSAR-X, the dual-frequency GPS receiver is of vital importance for the millimeter level determination of the baseline or distance between the two spacecrafts. The paper discusses the feasibility of generating millimeter baselines by the example of GRACE, where for validation the distance between the two GRACE satellites is directly available from the micrometer-level intersatellite link measurements. The distance of the GRACE satellites is some 200 km, the distance of the TerraSAR-X/TanDEM-X formation will be some 200 meters. Therefore the proposed approach is then subject to a simulation of the foreseen TerraSAR-X/TanDEM-X formation. The effect of varying space environmental conditions, of possible phase center variations, multi path, and of varying center of mass of the spacecrafts are evaluated and discussed.

  1. Detecting Blind Fault with Fractal and Roughness Factors from High Resolution LiDAR DEM at Taiwan

    NASA Astrophysics Data System (ADS)

    Cheng, Y. S.; Yu, T. T.

    2014-12-01

    There is no obvious fault scarp associated with blind fault. The traditional method of mapping this unrevealed geological structure is the cluster of seismicity. Neither the seismic event nor the completeness of cluster could be captured by network to chart the location of the entire possible active blind fault within short period of time. High resolution DEM gathered by LiDAR could denote actual terrain information despite the existence of plantation. 1-meter interval DEM of mountain region at Taiwan is utilized by fractal, entropy and roughness calculating with MATLAB code. By jointing these handing, the regions of non-sediment deposit are charted automatically. Possible blind fault associated with Chia-Sen earthquake at southern Taiwan is served as testing ground. GIS layer help in removing the difference from various geological formation, then multi-resolution fractal index is computed around the target region. The type of fault movement controls distribution of fractal index number. The scale of blind fault governs degree of change in fractal index. Landslide induced by rainfall and/or earthquake possesses larger degree of geomorphology alteration than blind fault; special treatment in removing these phenomena is required. Highly weathered condition at Taiwan should erase the possible trace remained upon DEM from the ruptured of blind fault while reoccurrence interval is higher than hundreds of years. This is one of the obstacle in finding possible blind fault at Taiwan.

  2. Development of New Accurate, High Resolution DEMs and Merged Topographic-Bathymetric Grids for Inundation Mapping in Seward Alaska

    NASA Astrophysics Data System (ADS)

    Marriott, D.; Suleimani, E.; Hansen, R.

    2004-05-01

    The Geophysical Institute of the University of Alaska Fairbanks and the Alaska Division of Geological and Geophysical Surveys continue to participate in the National Tsunami Hazard Mitigation Program by evaluating and mapping potential inundation of selected coastal communities in Alaska. Seward, the next Alaskan community to be mapped, has excellent bathymetric data but very poor topographic data available. Since one of the most significant sources of errors in tsunami inundation mapping is inaccuracy of topographic and bathymetric data, the Alaska Tsunami Modeling Team cooperated with the local USGS glaciology office to perform photogrammetry in the Seward area to produce a new DEM. Using ten air photos and the APEX photogrammetry and analysis software, along with several precisely located GPS points, we developed a new georeferenced and highly accurate DEM with a 5-meter grid spacing. A variety of techniques were used to remove the effects of buildings and trees to yield a bald earth model. Finally, we resampled the new DEM to match the finest resolution model grid, and combined it with all other data, using the most recent and accurate data in each region. The new dataset has contours that deviate by more than 100 meters in some places from the contours in the previous dataset, showing significant improvement in accuracy for the purpose of tsunami modeling.

  3. A simulation of wide area surveillance (WAS) systems and algorithm for digital elevation model (DEM) extraction

    NASA Astrophysics Data System (ADS)

    Cheng, Beato T.

    2010-04-01

    With the advances in focal plane, electronics and memory storage technologies, wide area and persistence surveillance capabilities have become a reality in airborne ISR. A WAS system offers many benefits in comparison with the traditional airborne image capturing systems that provide little data overlap, both in terms of space and time. Unlike a fix-mount surveillance camera, a persistence WAS system can be deployed anywhere as desired, although the platform typically has to be in motion, say circling above an area of interest. Therefore, WAS is a perfect choice for surveillance that can provide near real time capabilities such as change detection and target tracking. However, the performance of a WAS system is still limited by the available technologies: the optics that control the field-of-view, the electronics and mechanical subsystems that control the scanning, the focal plane data throughput, and the dynamics of the platform all play key roles in the success of the system. It is therefore beneficial to develop a simulated version that can capture the essence of the system, in order to help provide insights into the design of an optimized system. We describe an approach to the simulation of a generic WAS system that allows focal plane layouts, scanning patterns, flight paths and platform dynamics to be defined by a user. The system generates simulated image data of the area ground coverage from reference databases (e.g. aerial imagery, and elevation data), based on the sensor model. The simulated data provides a basis for further algorithm development, such as image stitching/mosaic, registration, and geolocation. We also discuss an algorithm to extract the terrain elevation from the simulated data, and to compare that with the original DEM data.

  4. DEM-based model for reconstructing volcano's morphology from primary volcanic landforms

    NASA Astrophysics Data System (ADS)

    Gayer, Eric; Lopez, Philippe; Michon, Laurent

    2014-05-01

    Volumes of magma intruded in and emitted by volcanoes through time can be estimated by reconstruction of volcano's morphology and time sequence. Classical approaches for quantifying magma volumes on active volcanoes are based on the difference between pre- and post-eruption digital elevation models (DEM), but this kind of approach needs the pre-eruptive surfaces to be available. For old and eroded volcanoes these surfaces are poorly constrained. However, because the geometrical form of many volcanic edifices exhibits a remarkable symmetry we propose, here, a new approach using primary volcanic landforms in order to estimate the amount of the both erupted and eroded material and to locate eruptive centers. A large fraction of composite volcanoes have near constant slope on their flanks and a form that is concave upwards near their summits. But many phenomena can lead to non-symetrical edifices and complex morphologies can result, for example from parasitic centers of volcanism on the flanks, from alternation of short effusive and explosive construction phases, from flank or caldera collapses, or from glacial and other types of erosion. In this study we propose that, on the first order approximation, complex morphologies can be modeled by piling regular cones. In this model, cones centers and slopes are derived by fitting primary volcanic landform with a linear function :elevation=f(distance from center). Such an approach allows to estimate both errors on location of the eruptive center and on the volume of the resulting cones. This model can then be used for quantifying volume of erupted and eroded material, and for quantifying catastrophic events as giant landslides or flank collapse. This approach is tested on four different active volcanoes : Mount Mayon (Philippines), Mount Fuji (Japan), Mount Etna (Sicily) and Mount Teide (Canary Island) to estimate errors in volume between modeled and actual edifices. It is then used on volcanoes of La Réunion hotspot to reconstruct the Piton des Neiges and Piton de la Fournaise volcanoes at its different stages of growing.

  5. Influence of H- and OH-adsorbates on the ethanol oxidation reaction--a DEMS study.

    PubMed

    Bach Delpeuch, Antoine; Chatenet, Marian; Rau, Maria Sol; Cremers, Carsten

    2015-04-28

    The ethanol oxidation reaction (EOR) was investigated by potentiodynamic techniques on Pt/C, Rh/C, Pt-Rh/C, Pt-SnO2/C and Pt-Rh-SnO2/C by differential electrochemical mass spectrometry (DEMS) in a flow cell system. Prior to the cyclic voltammetries, adsorption of H- and OH-species was carried out by chronoamperometry at Ead = 0.05 and 1 V vs. RHE, respectively, in order to examine their influence on the EOR on the different electrocatalysts. For the sake of comparison, another adsorption potential was chosen at Ead = 0.3 V vs. RHE, in the double layer region (i.e. in the absence of such adsorbates). For this study, 20 wt% electrocatalysts were synthesized using a modified polyol method and were physically characterized by inductively coupled plasma atomic emission spectrometry (ICP-AES), X-ray diffraction (XRD) and transmission electron microscopy (TEM). When comparing the first and second cycles of the cyclic voltammograms (CVs) on Pt/C and Pt-SnO2/C, the presence of Had on the electrocatalyst surface seems to hinder the initiation of the ethanol electrooxidation, whereas the reaction onset potential is shifted negatively with the presence of OH-adsorbates. In contrast to them, the EOR on Rh/C is enhanced when the electrocatalyst surface is covered with Had and is inhibited after adsorption at Ead = 0.3 and 1 V vs. RHE. Finally, on Pt-Rh/C and Pt-Rh-SnO2/C, neither the H- nor OH-adsorbates do impact the EOR initiation. The lowest EOR onset was recorded on Pt-SnO2/C and Pt-Rh-SnO2/C electrocatalysts. The CO2 currency efficiency (CCE) was also determined for each electrocatalyst and demonstrated higher values on Pt-Rh-SnO2/C. PMID:25820025

  6. Mapping hydrological environments in central Amazonia: ground validation and surface model based on SRTM DEM data corrected for deforestation

    NASA Astrophysics Data System (ADS)

    Moulatlet, G. M.; Rennó, C. D.; Costa, F. R. C.; Emilio, T.; Schietti, J.

    2015-03-01

    One of the most important freely available digital elevation models (DEMs) for Amazonia is the one obtained by the Shuttle Radar Topography Mission (SRTM). However, since SRTM tends to represent the vegetation surface instead of the ground surface, the broad use of SRTM DEM as a framework for terrain description in Amazonia is hampered by the presence of deforested areas. We present here two data sets: (1) a deforestation-corrected SRTM DEM for the interfluve between the Purus and Madeira rivers, in central Amazonia, which passed through a careful identification of different environments and has deforestation features corrected by a new method of increasing pixel values of the DEM (Rennó, 2009); and (2) a set of 18 hydrological-topographic descriptors based on the corrected SRTM DEM. Deforestation features are related with the opening of an 800 km road in the central part of the interfluve and occupancy of its vicinity. We used topographic profiles from the pristine forest to the deforested feature to evaluate the recovery of the original canopy coverage by minimizing canopy height variation (corrections ranged from 1 to 38 m). The hydrological-topographic description was obtained by the Height Above the Nearest Drainage (HAND) algorithm, which normalizes the terrain elevation (above sea level) by the elevation of the nearest hydrologically connected drainage. The validation of the HAND data set was done by in situ hydrological description of 110 km of walking trails also available in this data set. The new SRTM DEM expands the applicability of SRTM data for landscape modelling; the data sets of hydrological features based on topographic modelling are undoubtedly appropriate for ecological modelling and an important contribution to environmental mapping of Amazonia. The deforestation-corrected SRTM DEM is available at http://ppbio.inpa.gov.br/knb/metacat/naman.318.3/ppbio; the polygons selected for deforestation correction are available at http://ppbio.inpa.gov.br/knb/metacat/naman.317.3/ppbio; the set of hydrological-topographic descriptors is available at http://ppbio.inpa.gov.br/knb/metacat/naman.544.2/ppbio; the environmental description of access trails is available at http://ppbio.inpa.gov.br/knb/metacat/naman.541.2/ppbio; and the limits of deforestation corrections and drainage validation are available at http://ppbio.inpa.gov.br/knb/metacat/liliandias.38.1/ppbio.

  7. Coupled LBM-DEM Three-phase Simulation on Gas Flux Seeping from Marine Sediment

    NASA Astrophysics Data System (ADS)

    Kano, Y.; Sato, T.

    2014-12-01

    One of the main issues of the geological storage of CO2 under the seabed is a risk of CO2 leakage. Once CO2seeps into the ocean, it rises in water column dissolving into seawater, which results in the acidification of seawater and/or returning to the air. Its behaviour significantly depends on flow rate and bubble size (Kano et al., 2009; Dewar et al., 2013). As for porous media, bubble size is generally predicted through simple force balance based on flow rate, surface tension and channel size which is estimated by porosity and grain size. However, in shallow marine sediments, grains could be mobilised and displaced by buoyant gas flow, which causes distinctive phenomena such as blow-out or formation of gas flow conduit. As a result, effective gas flux into seawater can be intermissive, and/or concentrated in narrow area (QICS, 2012; Kawada, 2013). Bubble size is also affected by these phenomena. To predict effective gas flux and bubble size into seawater, three-phase behaviour of gas-water-sediment grains should be revealed. In this presentation, we will report the results of gas-liquid-solid three-phase simulations and their comparisons with experimental and observation data. Size of solid particles is based on grain size composing marine sediments at some CCS project sites. Fluid-particle interactions are solved using the lattice Boltzmann method (LBM), while the particle-particle interactions are treated by coupling with the Discrete Element method (DEM). References: Dewar, M., Wei, W., McNeil, D., Chen, B., 2013. Small-scale modelling of the physiochemical impacts of CO2leaked from sub-seabed reservoirs or pipelines within the North Sea and surrounding waters. Marine Pollution Bulletin 73(2), 504-515. Kano, Y., Sato, T., Kita, J., Hirabayashi, S., Tabeta, S., 2009. Model prediction on the rise of pCO2 in uniform flows by leakage of CO2purposefully stored under the seabed. Int. J. Greenhouse Gas Control, Vol. 3(5), 617-625. Kawada, R. 2014. A study on the mechanism which determines the size of bubbles seeping from sand sediment. Graduation thesis. Faculty of Engineering, The University of Tokyo. (in Japanese). QICS, 2012. QICS: Quantifying and Monitoring Potential Ecosystem Impacts of Geological Carbon Storage. (accessed Aug.06.14)

  8. Bonded 2D-DEM Models of Pit Craters and Collapse Calderas

    NASA Astrophysics Data System (ADS)

    Holohan, E. P.; Schöpfer, M. P. J.; Walsh, J. J.

    2010-05-01

    Subsidence of the roof of a magma reservoir commonly produces volcanic depressions, which, depending on scale, are termed pit craters or collapse calderas. To identify what geometric and mechanical factors influence the structural evolution of this subsidence, we used Distinct Element Method (DEM) numerical models. The models comprise an assemblage of gravitationally-loaded circular particles that interact at their contacts according to elastic-frictional laws. Cohesion is provided by inter-particle bonds that break once their shear or tensile strength is exceeded. Varying particle and bond micro-properties yields assemblage macro-properties characteristic of natural rock masses (e.g. elasticity, failure, and strain softening), with fracture localization simulated by bond breakage. The magma reservoir is represented as a region of non-bonded, low-fiction particles. Withdrawal of magma is simulated by incrementally reducing the area of the reservoir particles. The resultant gravity-driven failure and subsidence of the overlying reservoir roof is explicitly replicated. We investigated the effect on subsidence of several initial mechanical and geometric properties. Of these, the strength (cohesion) and thickness/diameter ratio (T/D) of the roof exerted strongest influences, whilst the roof's Young's Modulus and the reservoir's ceiling curvature imparted secondary influences. These properties interacted to produce four ‘end-member' subsidence styles, although elements of several styles tended to occur in any one model realization: (1) Predominantly central sagging at low T/D and low strength; (2) hitherto unrecognized ‘central snapping' at low T/D and high strength; (3) predominantly single central block subsidence at low to intermediate strength and at intermediate T/D ratios; (4) multiple central block subsidence at high strength and high T/D ratios. The critical T/D ratio, at which subsidence changes from single central block to multiple central block, was strongly dependent on material strength. Our model results provide a more quantitative understanding of the genesis of subsidence styles observed or inferred in the field: e.g. at Nindiri crater, Nicaragua; Dolomieu caldera, Reunion; and Miyakejima caldera, Japan.

  9. Forecasting of Storm-Surge Floods Using ADCIRC and Optimized DEMs

    NASA Technical Reports Server (NTRS)

    Valenti, Elizabeth; Fitzpatrick, Patrick

    2006-01-01

    Increasing the accuracy of storm-surge flood forecasts is essential for improving preparedness for hurricanes and other severe storms and, in particular, for optimizing evacuation scenarios. An interactive database, developed by WorldWinds, Inc., contains atlases of storm-surge flood levels for the Louisiana/Mississippi gulf coast region. These atlases were developed to improve forecasting of flooding along the coastline and estuaries and in adjacent inland areas. Storm-surge heights depend on a complex interaction of several factors, including: storm size, central minimum pressure, forward speed of motion, bottom topography near the point of landfall, astronomical tides, and, most importantly, maximum wind speed. The information in the atlases was generated in over 100 computational simulations, partly by use of a parallel-processing version of the ADvanced CIRCulation (ADCIRC) model. ADCIRC is a nonlinear computational model of hydrodynamics, developed by the U.S. Army Corps of Engineers and the US Navy, as a family of two- and three-dimensional finite-element-based codes. It affords a capability for simulating tidal circulation and storm-surge propagation over very large computational domains, while simultaneously providing high-resolution output in areas of complex shoreline and bathymetry. The ADCIRC finite-element grid for this project covered the Gulf of Mexico and contiguous basins, extending into the deep Atlantic Ocean with progressively higher resolution approaching the study area. The advantage of using ADCIRC over other storm-surge models, such as SLOSH, is that input conditions can include all or part of wind stress, tides, wave stress, and river discharge, which serve to make the model output more accurate. To keep the computational load manageable, this work was conducted using only the wind stress, calculated by using historical data from Hurricane Camille, as the input condition for the model. Hurricane storm-surge simulations were performed on an eight-node Linux computer cluster. Each node contained dual 2-GHz processors, 2GB of memory, and a 40GB hard drive. The digital elevation model (DEM) for this region was specified using a combination of Navy data (over water), NOAA data (for the coastline), and optimized Interferometric Synthetic Aperture Radar data (over land). This high-resolution topographical data of the Mississippi coastal region provided the ADCIRC model with improved input with which to calculate improved storm-surge forecasts.

  10. Sediment budget estimation in a small torrential catchment using DEM of difference approach

    NASA Astrophysics Data System (ADS)

    Bezak, Nejc; Grigillo, Dejan; Rusjan, Simon; Šraj, Mojca; Urban?i?, Tilen; Kozmus Trajkovski, Klemen; Petrovi?, Dušan; Mikoš, Matjaž

    2015-04-01

    The aim of the study was to estimate the sediment budget (net erosion change) in a small torrential catchment using the DEM of difference (DoD) approach. The Kuzlovec torrent (~ 0.7 km2; in the Gradaš?ica River catchment) is located approximately 20 km west of the City of Ljubljana and is part of the Sava River basin. The elevation ranges between 394 and 847 m.a.s.l, the mean catchment slope is 27.3°, the mean annual precipitation typically ranges between 1600 to 1800 mm, forest covers more than 85% of the area, and the predominant soil type is Rendzic Leptosol (according to the FAO classification). Using the Terestrical Laser Scanning (TLS) a digital terrain model (DTM) with a 5 cm grid cell was obtained. A smaller (about 25 m wide and 160 m long) specific study site with a mean slope of 37° was selected in order to ensure the high quality of data. A high resolution (several million points) surveys were performed in April 2013 and August 2014. In the night from 4th to 5th of August 2014 an extreme flash flood happened in the investigated area. Three tipping bucket rain gauges and one disdrometer, which are located in the Gradaš?ica River catchment, measured 110 to 185 mm of rainfall in less than 10 hours. Two rain gauges measured about 110 mm, one rain gauge (the closest to the Kuzloved torrent) recorded approximately 140 mm of rainfall, while the disdrometer measured 185 mm of rainfall. The estimated return period of this rainfall event (based on the rain gauge data) was between 100 and 250 years, however based on the disdrometer observations the return period was larger than 250 years. The Gumbel distribution was used in order to construct the intensity-duration-frequency (IDF) relationship and the data from 1976 to 2008 was used for this purpose. Furthermore, the maximum one minute rainfall intensity measured by the disdrometer was 288 mm/h. This high rainfall intensities triggered several shallow landslides and caused intense soil erosion processes, especially large bedload and suspended load movement along the stream channel network. A DoD approach was used to estimate the net erosion change in the selected section of the Kuzlovec torrent. A mean difference in the elevation between the DTM 2014 (after flash flood) and DTM 2013 (before flash flood) was -0.104 m. Based on the grid cell size (0.05 m) and number of cells (~ 1.93 106) a net erosion of about 500 m3 was calculated. Furthermore, uncertainty estimation is needed to validate the calculated net erosion change between two DTMs.

  11. Forecasting Rainfall Induced Landslide using High Resolution DEM and Simple Water Budget Model

    NASA Astrophysics Data System (ADS)

    Luzon, P. K. D.; Lagmay, A. M. F. A.

    2014-12-01

    Philippines is hit by an average of 20 typhoons per year bringing large amount of rainfall. Monsoon carrying rain coming from the southwest of the country also contributes to the annual total rainfall that causes different hazards. Such is shallow landslide mainly triggered by high saturation of soil due to continuous downpour which could take up from hours to days. Recent event like this happened in Zambales province September of 2013 where torrential rain occurred for 24 hours amounting to half a month of rain. Rainfall intensity measured by the nearest weather station averaged to 21 mm/hr from 10 pm of 22 until 10 am the following day. The monsoon rains was intensified by the presence of Typhoon Usagi positioned north and heading northwest of the country. A number of landslides due to this happened in 3 different municipalities; Subic, San Marcelino and Castillejos. The disaster have taken 30 lives from the province. Monitoring these areas for the entire country is but a big challenge in all aspect of disaster preparedness and management. The approach of this paper is utilizing the available forecast of rainfall amount to monitor highly hazardous area during the rainy seasons and forecasting possible landslide that could happen. A simple water budget model following the equation Perct=Pt-R/Ot-?STt-AETt (where as the terms are Percolation, Runoff, Change in Storage, and Actual Evapotraspiration) was implemented in quantifying all the water budget component. Computations are in Python scripted grid system utilizing the widely used GIS forms for easy transfer of data and faster calculation. Results of successive runs will let percolation and change in water storage as indicators of possible landslide.. This approach needs three primary sets of data; weather data, topographic data, and soil parameters. This research uses 5 m resolution DEM (IfSAR) to define the topography. Soil parameters are from fieldworks conducted. Weather data are from the Philippine Atmospheric, Geophysical and Astronomical Services Administration. The model is calibrated from stream gauges downsteam corresponding to the calculated runoff. Reliability of the results are as good as the data and is limited by the availability of such, though continuous enhancement of the method is expected as implementation progresses.

  12. Effects of Historical Landslide distribution and DEM resolution on the Accuracy of Landslide susceptibility mapping using Artificial Neural Network

    NASA Astrophysics Data System (ADS)

    Kawabata, D.; Bandibas, J.

    2013-12-01

    An efficient and accurate method of generating landslide susceptibility maps is very important to mitigate the loss of properties and lives caused by this type of geological hazard. The study area is Niigata, Japan sustained extensive landslide damage triggered by earthquake on 2004. This study focuses on the development of an accurate and efficient method of data integration, processing and generation of a landslide susceptibility map using an ANN (Artificial Neural Network), and data from some type of DEM (Digital Elevation Models) and landslide distribution map. DEM was generated from aerial photograph, laser scanning data, topographic map and ASTER. Two Landslide distribution maps are derived from NIED and GSI. The effects of the DEM resolution and landslide distribution on the accuracy of landslide susceptibility mapping has been analyzed using ANN in this study. The method contains two major phases. The first phase is the data integration and analysis, and the second is the artificial neural network training and mapping. The data integration and analysis phase involves GIS based statistical analysis relating landslide occurrence to geological and geomorphological parameters. The parameters include slope, aspect, elevation and geology. This phase determines the geological and geomorphological factors that are significantly correlated with landslide occurrence. The second phase further relates the landslide susceptibility index to the important geological and geomorphological parameters identified in the first phase through ANN training. The trained ANN is then used to generate a landslide susceptibility map. The area provided enough landslide data to check the efficiency and accuracy of the developed method. Based on the initial results of the experiment, the developed method is more than 90% accurate in determining the probability of landslide occurrence in a particular area.

  13. Extracting Precise and Affordable Dems Despite of the Clouds. Ajax: the Joining of Radar and Optical Strengths

    NASA Astrophysics Data System (ADS)

    Cunin, 1 L.; Nonin, 2 P.; Janoth, 3 J.; Bernard, 4 M.

    2012-07-01

    On the one hand, onboard SPOT 5, the HRS instrument systematically collects stereopairs around the Globe since 2002. Each stereopair can encompass an area up to 600 km x 120 km within a single pass (i.e. 72 000 km² stereoscopic strips). Covering now more than 120 millions sq.km of the Earth landmasses, SPOT 5 stereoscopic imagery has become one of main satellite data sources for accurate DEM extraction, at least where the cloud coverage leaves a chance to do so ! On the other hand, the TerraSAR-X satellite, launched in June 2007, is able to collect radar data through the clouds in several modes. An approach to extract height information by radargrammetry was developed, and the commercial distribution of Digital Elevation Models based on TerraSAR-X StripMap and SpotLight Modes (resp. 3m and 1m resolution) has started in 2010. To improve the overall height accuracy of the DEM, acquisitions from both orbit directions are utilised, each point on the ground being thus imaged at least 4 times by TerraSAR-X. Since 2002, Spot Image and French National Cartographic Institute (IGN) are building a worldwide database called Elevation30/Reference3D™, which includes a Digital Elevation Model at 1-arc-second resolution (DTED level 2) extracted from HRS stereopairs. To answer the wide demand of precise DEMs over Tropical and Northern areas, frequently covered by clouds, a study was performed to integrate StripMap radargrammetric TerraSAR-X data into the Reference3D process, and two prototype products were issued, over Colombia and Congo areas. During this experiment, efforts have been made to stick to technical steps that could be integrated within a standardized production process, in order to keep offering affordable prices while maintaining a high standard of horizontal and vertical accuracy. The DEMs extracted from TerraSAR-X and HRS proved extremely consistent with each other, showing a mean difference of 0.80m. This allows to propose a unified Elevation30 product to the users, with a guaranteed accuracy materialized into the product through a dedicated vertical Accuracy Commitment Mask.

  14. SveDem, the Swedish Dementia Registry – A Tool for Improving the Quality of Diagnostics, Treatment and Care of Dementia Patients in Clinical Practice

    PubMed Central

    Religa, Dorota; Fereshtehnejad, Seyed-Mohammad; Cermakova, Pavla; Edlund, Ann-Katrin; Garcia-Ptacek, Sara; Granqvist, Nicklas; Hallbäck, Anne; Kåwe, Kerstin; Farahmand, Bahman; Kilander, Lena; Mattsson, Ulla-Britt; Nägga, Katarina; Nordström, Peter; Wijk, Helle; Wimo, Anders; Winblad, Bengt; Eriksdotter, Maria

    2015-01-01

    Background The Swedish Dementia Registry (SveDem) was developed with the aim to improve the quality of diagnostic work-up, treatment and care of patients with dementia disorders in Sweden. Methods SveDem is an internet based quality registry where several indicators can be followed over time. It includes information about the diagnostic work-up, medical treatment and community support (www.svedem.se). The patients are diagnosed and followed-up yearly in specialist units, primary care centres or in nursing homes. Results The database was initiated in May 2007 and covers almost all of Sweden. There were 28 722 patients registered with a mean age of 79.3 years during 2007–2012. Each participating unit obtains continuous online statistics from its own registrations and they can be compared with regional and national data. A report from SveDem is published yearly to inform medical and care professionals as well as political and administrative decision-makers about the current quality of diagnostics, treatment and care of patients with dementia disorders in Sweden. Conclusion SveDem provides knowledge about current dementia care in Sweden and serves as a framework for ensuring the quality of diagnostics, treatment and care across the country. It also reflects changes in quality dementia care over time. Data from SveDem can be used to further develop the national guidelines for dementia and to generate new research hypotheses. PMID:25695768

  15. Developing and programming a watershed traversal algorithm (WTA) in GRID-DEM and adapting it to hydrological processes

    NASA Astrophysics Data System (ADS)

    Mateo Lázaro, Jesús; Sánchez Navarro, José Ángel; García Gil, Alejandro; Edo Romero, Vanesa

    2013-02-01

    A methodology for programming hydrological processes into watersheds using grid-type digital elevation models (DEMs) is investigated. This methodology is based on the basic configuration of the flow directions structure in the DEM, which is stored in files where information about topological relations and other frequently used features are saved. Some basic functions for managing topological data that significantly simplify the source code programming are also presented and described. We develop an algorithm that runs the entire drainage network in a watershed in both directions, upwards and downwards, which is ideal for incorporating structural models of hydrological processes that occur in basins or assessing its characteristics. The main attribute of this method is that information about hydrological processes and properties is transmitted during the routing from one area to another of the basin. The information is used when developing models of these hydrological processes and transmitted throughout the basin. At the end of the article, using this methodology with the SHEE software is illustrated with some examples.

  16. DEM-based Approaches for the Identification of Flood Prone Areas

    NASA Astrophysics Data System (ADS)

    Samela, Caterina; Manfreda, Salvatore; Nardi, Fernando; Grimaldi, Salvatore; Roth, Giorgio; Sole, Aurelia

    2013-04-01

    The remarkable number of inundations that caused, in the last decades, thousands of deaths and huge economic losses, testifies the extreme vulnerability of many Countries to the flood hazard. As a matter of fact, human activities are often developed in the floodplains, creating conditions of extremely high risk. Terrain morphology plays an important role in understanding, modelling and analyzing the hydraulic behaviour of flood waves. Research during the last 10 years has shown that the delineation of flood prone areas can be carried out using fast methods that relay on basin geomorphologic features. In fact, the availability of new technologies to measure surface elevation (e.g., GPS, SAR, SAR interferometry, RADAR and LASER altimetry) has given a strong impulse to the development of Digital Elevation Models (DEMs) based approaches. The identification of the dominant topographic controls on the flood inundation process is a critical research question that we try to tackle with a comparative analysis of several techniques. We reviewed four different approaches for the morphological characterization of a river basin with the aim to provide a description of their performances and to identify their range of applicability. In particular, we explored the potential of the following tools. 1) The hydrogeomorphic method proposed by Nardi et al. (2006) which defines the flood prone areas according to the water level in the river network through the hydrogeomorphic theory. 2) The linear binary classifier proposed by Degiorgis et al. (2012) which allows distinguishing flood-prone areas using two features related to the location of the site under exam with respect to the nearest hazard source. The two features, proposed in the study, are the length of the path that hydrologically connects the location under exam to the nearest element of the drainage network and the difference in elevation between the cell under exam and the final point of the same path. 3) The method by Manfreda et al. (2011) that suggested a modified Topographic Index (TIm) for the identification of flood prone area. 4) The downslope index proposed by Hjerdt et al. (2004) that quantifies the topographic controls on hydrology by evaluating head differences following the (surface) flow path in the steepest direction. The method does not use the exit point at the stream as reference; instead, the algorithm looks at how far a parcel of water has to travel along its flow path to lose a given head potential, d [m]. This last index was not defined with the aim to describe flood prone areas; in fact it represents an interesting alternative descriptor of morphological features that deserve to be tested. Analyses have been carried out for some Italian catchments. The outcomes of the four methods are presented using, for calibration and validation purposes, flood inundation maps made available by River Basin Authorities. The aim is, therefore, to evaluate the reliability and the relative errors in the detection of the areas subject to the flooding hazard. These techniques should not be considered as an alternative of traditional procedures, but additional tool for the identification of flood-prone areas and hazard graduation over large regions or when a preliminary identification is needed. Reference Degiorgis M., G. Gnecco, S. Gorni, G. Roth, M. Sanguineti, A. C. Taramasso, Classifiers for the detection of flood-prone areas using remote sensed elevation data, J. Hydrol., 470-471, 302-315, 2012. Hjerdt, K. N., J. J. McDonnell, J. Seibert, A. Rodhe, A new topographic index to quantify downslope controls on local drainage, Water Resour. Res., 40, W05602, 2004. Manfreda, S., M. Di Leo, A. Sole, Detection of Flood Prone Areas using Digital Elevation Models, Journal of Hydrologic Engineering, Vol. 16, No. 10, 781-790, 2011. Nardi, F., E. R. Vivoni, S. Grimaldi, Investigating a floodplain scaling relation using a hydrogeomorphic delineation method, Water Resour. Res., 42, W09409, 2006.

  17. Low-altitude remote sensing dataset of DEM and RGB mosaic for AB corridor on July 13 2013 and L2 corridor on July 21 2013

    SciTech Connect

    Baptiste Dafflon

    2015-04-07

    Low-altitude remote sensing dataset including DEM and RGB mosaic for AB (July 13 2013) and L2 corridor (July 21 2013).Processing flowchart for each corridor:Ground control points (GCP, 20.3 cm square white targets, every 20 m) surveyed with RTK GPS. Acquisition of RGB pictures using a Kite-based platform. Structure from Motion based reconstruction using hundreds of pictures and GCP coordinates. Export of DEM and RGB mosaic in geotiff format (NAD 83, 2012 geoid, UTM zone 4 north) with pixel resolution of about 2 cm, and x,y,z accuracy in centimeter range (less than 10 cm). High-accuracy and high-resolution inside GCPs zone for L2 corridor (500x20m), AB corridor (500x40) DEM will be updated once all GCPs will be measured. Only zones between GCPs are accurate although all the mosaic is provided.

  18. Amundsen Sea sector ice shelf thickness, melt rates, and inland response from annual high-resolution DEM mosaics

    NASA Astrophysics Data System (ADS)

    Shean, D. E.; Joughin, I. R.; Smith, B. E.; Alexandrov, O.; Moratto, Z.; Porter, C. C.; Morin, P. J.

    2014-12-01

    Significant grounding line retreat, acceleration, and thinning have occurred along the Amundsen Sea sector of West Antarctica in recent decades. These changes are driven primarily by ice-ocean interaction beneath ice shelves, but existing observations of the spatial distribution, timing, and magnitude of ice shelf melt are limited. Using the NASA Ames Stereo Pipeline, we generated digital elevation models (DEMs) with ~2 m posting from all ~450 available WorldView-1/2 along-track stereopairs for the Amundsen Sea sector. A novel iterative closest point algorithm was used to coregister DEMs to filtered Operation IceBridge ATM/LVIS data and ICESat-1 GLAS data, offering optimal sub-meter horizontal/vertical accuracy. The corrected DEMs were used to produce annual mosaics for the entire ~500x700 km region with focused, sub-annual products for ice shelves and grounding zones. These mosaics provide spatially-continuous measurements of ice shelf topography with unprecedented detail. Using these data, we derive estimates of ice shelf thickness for regions in hydrostatic equilibrium and map networks of sub-shelf melt channels for the Pine Island (PIG), Thwaites, Crosson, and Dotson ice shelves. We also document the break-up of the Thwaites ice shelf and PIG rift evolution leading up to the 2013 calving event. Eulerian difference maps document 2010-2014 thinning over fast-flowing ice streams and adjacent grounded ice. These data reveal the greatest thinning rates over the Smith Glacier ice plain and slopes beyond the margins of the fast-flowing PIG trunk. Difference maps also highlight the filling of at least two subglacial lakes ~30 km upstream of the PIG grounding line in 2011. Lagrangian difference maps reveal the spatial distribution of ice shelf thinning, which can primarily be attributed to basal melt. Preliminary results show focused ice shelf thinning within troughs and large basal channels, especially along the western margin of the Dotson ice shelf. These new data provide critical observations that will improve our understanding ice-ocean interaction and mass loss for the Amundsen Sea sector on local and regional scales.

  19. Analysis of the seasonal and interannual evolution of Jakobshavn Isbrae from 2010-2013 using high spatial/temporal resolution DEM and velocity data

    NASA Astrophysics Data System (ADS)

    Shean, D. E.; Joughin, I. R.; Smith, B. E.; Moratto, Z. M.; Alexandrov, O.; Floricioiu, D.; Morin, P. J.; Porter, C. C.; Beyer, R. A.; Fong, T.

    2013-12-01

    Greenland's large marine-terminating outlet glaciers have displayed marked retreat, speedup, and thinning in recent decades. Jakobshavn Isbrae, one of Greenland's largest outlet glaciers, has retreated ~15 km, accelerated ~150%, and thinned ~200 m since the early 1990s. Here, we present the first comprehensive analysis of high spatial (~2-5 m/px) and temporal (daily-monthly) resolution elevation and velocity data for Jakobshavn from 7/2010 to 7/2013. We have developed an automated processing pipeline using open-source software (Ames Stereo Pipeline, GDAL/OGR, NumPy/SciPy, etc.) to produce orthoimage, digital elevation model (DEM), and surface velocity products from DigitalGlobe WorldView-1/2 stereo imagery (~0.5 m/px, ~17 km swath width). Our timeseries consists of 35 WV DEMs (~2-4 m/px) covering the lower trunks of the main+north branches and fjord, but also extending >110 km inland. We supplement this record with 7 TanDEM-X DEMs (~5 m/px, ~35 km swath width) between 6/2011-9/2012. Elevation data from IceBridge ATM/LVIS, ICESat GLAS, and GPS campaigns provide absolute control data over fixed surfaces (i.e., exposed bedrock). Observed WV DEM offsets are consistent with DigitalGlobe's published value of 5.0 m CE90/LE90 horizontal/vertical accuracy. After DEM co-registration, we observe sub-meter horizontal and vertical absolute accuracy. Velocity data are derived from TerraSAR-X data with 11 day repeat interval. Supplemental velocity data are derived through correlation of high-resolution WV DEM/image data. The contemporaneous DEM and velocity data provide full 3D displacement vectors for each time interval, allowing for the analysis of both Eulerian and Lagrangian elevation change. The lower trunk of Jakobshavn displays significant seasonal velocity variations, with recent rates of ~8 km/yr during winter to >17 km/yr during summer. DEM data show corresponding elevation changes of -30 to -45 m in summer and +15 to +20 m in winter, corresponding to integrated volumes of -1.0 to -1.5 km3 and +0.3 to +0.6 km3 for the lower ~20 km of the main trunk. Further analysis will characterize the upstream propagation of the seasonal elevation change and the relationship with observed strain rates. Seasonal surface mass balance elevation changes are also observed over adjacent grounded, slow-moving (~100 m/yr) regions. The DEM timeseries shows a net interannual thinning trend of -15-20 m/yr for lower Jakobshavn, with decreasing magnitude upstream. This is consistent with long-term altimetry records. Interannual thinning of ~2 m/yr and lateral retreat is also observed for grounded ice sheet margins. These DEM and velocity data capture the timing, magnitude and evolution of dynamic thinning/thickening with unprecedented spatial and temporal resolution. These results also emphasize the importance of dense temporal elevation data when characterizing ice sheet variability and interpreting deviations from long-term records. Similar high-resolution timeseries are available for all major outlet glaciers and ice streams in Greenland and Antarctica. Ultimately, these observations will improve our understanding of outlet glacier behavior, while complementing ongoing efforts to constrain estimates for ice-sheet mass balance and contribution to present/future sea level rise.

  20. The evaluation of unmanned aerial system-based photogrammetry and terrestrial laser scanning to generate DEMs of agricultural watersheds

    NASA Astrophysics Data System (ADS)

    Ouédraogo, Mohamar Moussa; Degré, Aurore; Debouche, Charles; Lisein, Jonathan

    2014-06-01

    Agricultural watersheds tend to be places of intensive farming activities that permanently modify their microtopography. The surface characteristics of the soil vary depending on the crops that are cultivated in these areas. Agricultural soil microtopography plays an important role in the quantification of runoff and sediment transport because the presence of crops, crop residues, furrows and ridges may impact the direction of water flow. To better assess such phenomena, 3-D reconstructions of high-resolution agricultural watershed topography are essential. Fine-resolution topographic data collection technologies can be used to discern highly detailed elevation variability in these areas. Knowledge of the strengths and weaknesses of existing technologies used for data collection on agricultural watersheds may be helpful in choosing an appropriate technology. This study assesses the suitability of terrestrial laser scanning (TLS) and unmanned aerial system (UAS) photogrammetry for collecting the fine-resolution topographic data required to generate accurate, high-resolution digital elevation models (DEMs) in a small watershed area (12 ha). Because of farming activity, 14 TLS scans (? 25 points m- 2) were collected without using high-definition surveying (HDS) targets, which are generally used to mesh adjacent scans. To evaluate the accuracy of the DEMs created from the TLS scan data, 1098 ground control points (GCPs) were surveyed using a real time kinematic global positioning system (RTK-GPS). Linear regressions were then applied to each DEM to remove vertical errors from the TLS point elevations, errors caused by the non-perpendicularity of the scanner's vertical axis to the local horizontal plane, and errors correlated with the distance to the scanner's position. The scans were then meshed to generate a DEMTLS with a 1 × 1 m spatial resolution. The Agisoft PhotoScan and MicMac software packages were used to process the aerial photographs and generate a DEMPSC (Agisoft PhotoScan) and DEMMCM (MicMac), respectively, with spatial resolutions of 1 × 1 m. Comparing the DEMs with the 1098 GCPs showed that the DEMTLS was the most accurate data product, with a root mean square error (RMSE) of 4.5 cm, followed by the DEMMCM and the DEMPSC, which had RMSE values of 9.0 and 13.9 cm, respectively. The DEMPSC had absolute errors along the border of the study area that ranged from 15.0 to 52.0 cm, indicating the presence of systematic errors. Although the derived DEMMCM was accurate, an error analysis along a transect showed that the errors in the DEMMCM data tended to increase in areas of lower elevation. Compared with TLS, UAS is a promising tool for data collection because of its flexibility and low operational cost. However, improvements are needed in the photogrammetric processing of the aerial photographs to remove non-linear distortions.

  1. Improvement of Forest Height Retrieval By Integration of Dual-Baseline PolInSAR Data And External DEM Data

    NASA Astrophysics Data System (ADS)

    Xie, Q.; Wang, C.; Zhu, J.; Fu, H.; Wang, C.

    2015-06-01

    In recent years, a lot of studies have shown that polarimetric synthetic aperture radar interferometry (PolInSAR) is a powerful technique for forest height mapping and monitoring. However, few researches address the problem of terrain slope effect, which will be one of the major limitations for forest height inversion in mountain forest area. In this paper, we present a novel forest height retrieval algorithm by integration of dual-baseline PolInSAR data and external DEM data. For the first time, we successfully expand the S-RVoG (Sloped-Random Volume over Ground) model for forest parameters inversion into the case of dual-baseline PolInSAR configuration. In this case, the proposed method not only corrects terrain slope variation effect efficiently, but also involves more observations to improve the accuracy of parameters inversion. In order to demonstrate the performance of the inversion algorithm, a set of quad-pol images acquired at the P-band in interferometric repeat-pass mode by the German Aerospace Center (DLR) with the Experimental SAR (E-SAR) system, in the frame of the BioSAR2008 campaign, has been used for the retrieval of forest height over Krycklan boreal forest in northern Sweden. At the same time, a high accuracy external DEM in the experimental area has been collected for computing terrain slope information, which subsequently is used as an inputting parameter in the S-RVoG model. Finally, in-situ ground truth heights in stand-level have been collected to validate the inversion result. The preliminary results show that the proposed inversion algorithm promises to provide much more accurate estimation of forest height than traditional dualbaseline inversion algorithms.

  2. A hierarchical pyramid method for managing large-scale high-resolution drainage networks extracted from DEM

    NASA Astrophysics Data System (ADS)

    Bai, Rui; Tiejian, Li; Huang, Yuefei; Jiaye, Li; Wang, Guangqian; Yin, Dongqin

    2015-12-01

    The increasing resolution of Digital Elevation Models (DEMs) and the development of drainage network extraction algorithms make it possible to develop high-resolution drainage networks for large river basins. These vector networks contain massive numbers of river reaches with associated geographical features, including topological connections and topographical parameters. These features create challenges for efficient map display and data management. Of particular interest are the requirements of data management for multi-scale hydrological simulations using multi-resolution river networks. In this paper, a hierarchical pyramid method is proposed, which generates coarsened vector drainage networks from the originals iteratively. The method is based on the Horton-Strahler's (H-S) order schema. At each coarsening step, the river reaches with the lowest H-S order are pruned, and their related sub-basins are merged. At the same time, the topological connections and topographical parameters of each coarsened drainage network are inherited from the former level using formulas that are presented in this study. The method was applied to the original drainage networks of a watershed in the Huangfuchuan River basin extracted from a 1-m-resolution airborne LiDAR DEM and applied to the full Yangtze River basin in China, which was extracted from a 30-m-resolution ASTER GDEM. In addition, a map-display and parameter-query web service was published for the Mississippi River basin, and its data were extracted from the 30-m-resolution ASTER GDEM. The results presented in this study indicate that the developed method can effectively manage and display massive amounts of drainage network data and can facilitate multi-scale hydrological simulations.

  3. Numerical slope stability simulations of chasma walls in Valles Marineris/Mars using a distinct element method (dem).

    NASA Astrophysics Data System (ADS)

    Imre, B.

    2003-04-01

    NUMERICAL SLOPE STABILITY SIMULATIONS OF CHASMA WALLS IN VALLES MARINERIS/MARS USING A DISTINCT ELEMENT METHOD (DEM). B. Imre (1) (1) German Aerospace Center, Berlin Adlershof, bernd.imre@gmx.net The 8- to 10-km depths of Valles Marineris (VM) offer excellent views into the upper Martian crust. Layering, fracturing, lithology, stratigraphy and the content of volatiles have influenced the evolution of the Valles Marineris wallslopes. But these parameters also reflect the development of VM and its wall slopes. The scope of this work is to gain understanding in these parameters by back-simulating the development of wall slopes. For that purpose, the two dimensional Particle Flow Code PFC2D has been chosen (ITASCA, version 2.00-103). PFC2D is a distinct element code for numerical modelling of movements and interactions of assemblies of arbitrarily sized circular particles. Particles may be bonded together to represent a solid material. Movements of particles are unlimited. That is of importance because results of open systems with numerous unknown variables are non-unique and therefore highly path dependent. This DEM allows the simulation of whole development paths of VM walls what makes confirmation of the model more complete (e.g. Oreskes et al., Science 263, 1994). To reduce the number of unknown variables a proper (that means as simple as possible) field-site had to be selected. The northern wall of eastern Candor Chasma has been chosen. This wall is up to 8-km high and represents a significant outcrop of the upper Martian crust. It is quite uncomplex, well-aligned and of simple morphology. Currently the work on the model is at the stage of performing the parameter study. Results will be presented via poster by the EGS-Meeting.

  4. Inter-annual surface evolution of an Antarctic blue-ice moraine using multi-temporal DEMs

    NASA Astrophysics Data System (ADS)

    Westoby, M. J.; Dunning, S. A.; Woodward, J.; Hein, A. S.; Marrero, S. M.; Winter, K.; Sugden, D. E.

    2015-11-01

    Multi-temporal and fine resolution topographic data products are being increasingly used to quantify surface elevation change in glacial environments. In this study, we employ 3-D digital elevation model (DEM) differencing to quantify the topographic evolution of a blue-ice moraine complex in front of Patriot Hills, Heritage Range, Antarctica. Terrestrial laser scanning (TLS) was used to acquire multiple topographic datasets of the moraine surface at the beginning and end of the austral summer season in 2012/2013 and during a resurvey field campaign in 2014. A complementary topographic dataset was acquired at the end of season 1 through the application of Structure-from-Motion (SfM) photogrammetry to a set of aerial photographs taken from an unmanned aerial vehicle (UAV). Three-dimensional cloud-to-cloud differencing was undertaken using the Multiscale Model to Model Cloud Comparison (M3C2) algorithm. DEM differencing revealed net uplift and lateral movement of the moraine crests within season 1 (mean uplift ∼ 0.10 m), with lowering of a similar magnitude in some inter-moraine depressions and close to the current ice margin. Our results indicate net uplift across the site between seasons 1 and 2 (mean 0.07 m). This research demonstrates that it is possible to detect dynamic surface topographical change across glacial moraines over short (annual to intra-annual) timescales through the acquisition and differencing of fine-resolution topographic datasets. Such data offer new opportunities to understand the process linkages between surface ablation, ice flow, and debris supply within moraine ice.

  5. Automated classifications of topography from DEMs by an unsupervised nested-means algorithm and a three-part geometric signature

    NASA Astrophysics Data System (ADS)

    Iwahashi, Junko; Pike, Richard J.

    2007-05-01

    An iterative procedure that implements the classification of continuous topography as a problem in digital image-processing automatically divides an area into categories of surface form; three taxonomic criteria-slope gradient, local convexity, and surface texture-are calculated from a square-grid digital elevation model (DEM). The sequence of programmed operations combines twofold-partitioned maps of the three variables converted to greyscale images, using the mean of each variable as the dividing threshold. To subdivide increasingly subtle topography, grid cells sloping at less than mean gradient of the input DEM are classified by designating mean values of successively lower-sloping subsets of the study area (nested means) as taxonomic thresholds, thereby increasing the number of output categories from the minimum 8 to 12 or 16. Program output is exemplified by 16 topographic types for the world at 1-km spatial resolution (SRTM30 data), the Japanese Islands at 270 m, and part of Hokkaido at 55 m. Because the procedure is unsupervised and reflects frequency distributions of the input variables rather than pre-set criteria, the resulting classes are undefined and must be calibrated empirically by subsequent analysis. Maps of the example classifications reflect physiographic regions, geological structure, and landform as well as slope materials and processes; fine-textured terrain categories tend to correlate with erosional topography or older surfaces, coarse-textured classes with areas of little dissection. In Japan the resulting classes approximate landform types mapped from airphoto analysis, while in the Americas they create map patterns resembling Hammond's terrain types or surface-form classes; SRTM30 output for the United States compares favorably with Fenneman's physical divisions. Experiments are suggested for further developing the method; the Arc/Info AML and the map of terrain classes for the world are available as online downloads.

  6. Automated classifications of topography from DEMs by an unsupervised nested-means algorithm and a three-part geometric signature

    USGS Publications Warehouse

    Iwahashi, J.; Pike, R.J.

    2007-01-01

    An iterative procedure that implements the classification of continuous topography as a problem in digital image-processing automatically divides an area into categories of surface form; three taxonomic criteria-slope gradient, local convexity, and surface texture-are calculated from a square-grid digital elevation model (DEM). The sequence of programmed operations combines twofold-partitioned maps of the three variables converted to greyscale images, using the mean of each variable as the dividing threshold. To subdivide increasingly subtle topography, grid cells sloping at less than mean gradient of the input DEM are classified by designating mean values of successively lower-sloping subsets of the study area (nested means) as taxonomic thresholds, thereby increasing the number of output categories from the minimum 8 to 12 or 16. Program output is exemplified by 16 topographic types for the world at 1-km spatial resolution (SRTM30 data), the Japanese Islands at 270??m, and part of Hokkaido at 55??m. Because the procedure is unsupervised and reflects frequency distributions of the input variables rather than pre-set criteria, the resulting classes are undefined and must be calibrated empirically by subsequent analysis. Maps of the example classifications reflect physiographic regions, geological structure, and landform as well as slope materials and processes; fine-textured terrain categories tend to correlate with erosional topography or older surfaces, coarse-textured classes with areas of little dissection. In Japan the resulting classes approximate landform types mapped from airphoto analysis, while in the Americas they create map patterns resembling Hammond's terrain types or surface-form classes; SRTM30 output for the United States compares favorably with Fenneman's physical divisions. Experiments are suggested for further developing the method; the Arc/Info AML and the map of terrain classes for the world are available as online downloads. ?? 2006 Elsevier B.V. All rights reserved.

  7. Die MHH wurde in dem Projekt WiKiZ (Wirtschaft Kinder Zukunft) von den Wirtschaftsjunioren Hannover ,,fr eine herausragende Lsung der Kinderbetreuung whrend der Arbeitszeit"

    E-print Network

    Manstein, Dietmar J.

    Die MHH wurde in dem Projekt WiKiZ (Wirtschaft ­ Kinder ­ Zukunft) von den Wirtschaftsjunioren erhielt einen von drei ersten Preisen. Die MHH Gleichstellungsbeauftragte Dr. Bärbel Miemietz und die Preisverleihung im Plenarsaal der IHK Hannover die Urkunde für die MHH entgegen. Die Laudatorin Jasmin Arbabian

  8. Site-specific assessment of the rockfall and the rock block volume distribution relations, using a LIDAR generated DEM

    NASA Astrophysics Data System (ADS)

    Mavrouli, Olga; Corominas, Jordi; Jaboyedoff, Michel

    2014-05-01

    The quantification of the rockfall hazard and, in particular of the rockfall propagation, requires information on the expected probability or frequency of rockfalls of a given magnitude (size), usually in the form of magnitude-frequency M-F relations. Two kinds of relations are needed. The first one characterises the rockfall masses that can be potentially detached from the slope face giving information on the volume distribution of rockfalls. From now on, this will be referred to as potential rockfall volume distribution VDR. For fragmental rockfalls, the evaluation of the VDR can be a first step towards the temporal M-F, The second one characterises the volume distribution of the rock blocks that result from the disintegration of the previous rockfall masses due to impact with the ground. This one will be referred to as rock block volume distribution VDB. In this work we present two analytical procedures which are independent from the existence of empirical data, for: (i) The calculation of the potential VDR that refers to big volumes with low probability of occurrence. This is realised by detection of the kinematically unstable surfaces on a DEM and on orthophotos, and calculation of the volumes that correspond to them. The basic assumptions here describing a conservative scenario of very low probability are: (a) the rockfall mass is detached entirely at a single rockfall event, without taking into account that smaller successive failures are possible instead; (b) all discontinuity sets are present everywhere in the slope and have infinite persistence; and (c) big stepped-path failures are possible. (ii) The assessment of the in-situ rock blocks volume distribution on the slope face, VDB, by calculation of the volume of the prisms which are formed by the intersection of the existing discontinuity sets and are kinematically unstable. This is also based on data obtained by DEM analysis. A high-resolution DEM obtained by Lidar is used. Both procedures are presented though an application example at the country of Andorra and in particular at the chute of Forat Negre. The results from the first procedure indicate that it is kinematically possible to have mobilised volumes of some thousands of cubic meters although the probability of generating large volumes is low. The VDR for big volume events was well fitted by a power-law equal to -0.5. The VDB from the second procedure, assuming three intersection types within the discontinuity network and two extreme cases of discontinuity persistence, was also found to follow a power-law, with exponent -1.3. The comparison with field data collected by past studies in the same area indicates that in reality, the discontinuities have a very high persistence and that considering only their visible trace length is very conservative.

  9. Developing sub 5-m LiDAR DEMs for forested sections of the Alpine and Hope faults, South Island, New Zealand: Implications for structural interpretations

    NASA Astrophysics Data System (ADS)

    Langridge, R. M.; Ries, W. F.; Farrier, T.; Barth, N. C.; Khajavi, N.; De Pascale, G. P.

    2014-07-01

    Kilometre-wide airborne light detection and ranging (LiDAR) surveys were collected along portions of the Alpine and Hope faults in New Zealand to assess the potential for generating sub 5-m bare earth digital elevation models (DEMs) from ground return data in areas of dense rainforest (bush) cover as an aid to mapping these faults. The 34-km long Franz-Whataroa LiDAR survey was flown along the densely-vegetated central-most portion of the transpressive Alpine Fault. Six closely spaced flight lines (200 m apart) yielded survey coverage with double overlap of swath collection, which was considered necessary due to the low density of ground returns (0.16 m-2 or a point every 6 m2) under mature West Coast podocarp-broadleaf rainforest. This average point spacing (˜2.5 m) allowed for the generation of a robust, high quality 3-m bare earth DEM. The DEM confirmed the zigzagged form of the surface trace of the Alpine Fault in this area, originally recognised by Norris and Cooper (1995, 1997) and highlights that the surface strike variations are more variant than previously mapped. The 29-km long Hurunui-Hope LiDAR survey was flown east of the Main Divide of the Southern Alps along the dextral-slip Hope Fault, where the terrain is characterised by lower rainfall and more open beech forest. Flight line spacings of ˜275 m were used to generate a DEM from the ground return data. The average ground return values under beech forest were 0.27 m-2 and yielded an estimated cell size suitable for a 2-m DEM. In both cases the LiDAR revealed unprecedented views of the surface geomorphology of these active faults. Lessons learned from our survey methodologies can be employed to plan cost-effective, high-gain airborne surveys to yield bare earth DEMs underneath vegetated terrain and multi-storeyed canopies from densely forested environments across New Zealand and worldwide.

  10. Empirical relationships among triangular facet slope, facet height and slip rates along active normal faults from ASTER DEM data

    NASA Astrophysics Data System (ADS)

    Tsimi, Christina; Ganas, Athanassios

    2015-04-01

    ASTER DEM data (30-m pixel size) are used to derive empirical relationships between triangular facet attributes and slip rates along active normal faults. We sampled 232 triangular facets along 10 normal faults in Greece and Bulgaria that slip with rates from 0.1 mm/yr up to 1.3 mm/yr. The studied normal faults accumulate Quaternary tectonic strain in well-known extensional provinces, such as central Greece, Crete and SW Bulgaria. The normal fault footwalls analysed herein have been developed under similar long-term climatic conditions. It is suggested that two key geometrical features of the youngest generation of triangular facets (slope angle and height) can provide useful metrics to assess rates of deformation when seismological and geodetic data are lacking or not found in sufficient quantity to make reasonable assessments. Our derived empirical relation between slip rate and facet slope angle is: Y=0.057•X-1 where Y is fault slip rate (mm/yr) and X is facet slope angle (degrees), with an R² = 0.728. It is envisaged that our analysis may be helpful in assessing seismic hazard along normal faults with similar facet characteristics in other extensional settings. Note: This research was funded by The Rapid Analysis and Spatialisation Of Risk (RASOR) project http://www.rasor-project.eu/

  11. DEM analyses of the whole failure process of shallow foundation in plate load test on dense sand

    NASA Astrophysics Data System (ADS)

    Li, L.; Jiang, M. J.; Li, T.; Chen, S. L.

    2015-09-01

    Shallow foundations are widely used in civil engineering practice, but the instability mechanism is still unclear yet. Previously, the Finite Element Method (FEM) was commonly used to analyze the failure process of shallow foundations, but it meets difficulty in properly simulating the whole failure process of shallow foundation on the strain-softening material. Hence, the Discrete Element Method (DEM) is employed in this paper to study the instability mechanism of the shallow foundation via numerical plate load test with focus on the microscopic features evolution during vertical loading. In the simulation, an amplified gravity was applied to a dense granular ground to reproduce a gravity stress state at a large scale. Then, a plate was put on the granular ground to simulate the plate load test. Deformation pattern, particle velocity and distribution of void ratio in the ground were examined to illustrate the microscopic features in the whole failure process of the granular ground. The results show that: 1) There are a marked peak value and a settlement softening branch in the stress-settlement relationship. 2) The grids close to the edge of the plate are peculiarly extended and twisted. 3) Four particle motion patterns were observed in the velocity fields and the percentage of each motion pattern changes during loading. 4) The void ratio field varies during loading, and the distinguishing interface tends to be similar to Terzaghi's shear failure surface.

  12. An iterative LiDAR DEM-aided algorithm for GNSS positioning in obstructed/rapidly undulating environments

    NASA Astrophysics Data System (ADS)

    Danezis, Chris; Gikas, Vassilis

    2013-09-01

    This paper describes a new algorithm to aid stand-alone GNSS positioning in areas of bad signal reception using a Digital Elevation Model (DEM). Traditional Height-Aiding (HA) algorithms assume either a preset (fixed) value for the receiver elevation or rely on the elevation value that corresponds to the nearest available position fix. This may lead in erroneous receiver elevation estimates that, under circumstances, are inefficient to aid effectively GNSS positioning. In this study, the receiver elevation is updated at every iteration step of the navigation solution through dynamic interpolation of the elevation model. The algorithm, because of its ability to extract and fully exploit the elevation information derived from a digital model, it can prove particularly useful in forested areas with steep-sloped terrain. Extended test runs were undertaken to validate the correctness of the mathematical model and the feasibility of the algorithm and associated software. Particularly, analysis of a dataset acquired in a forested, rapidly undulating environment reveals significant average improvement in all performance metrics of positioning, namely the GNSS position availability (50%), accuracy (56%) and external reliability (86%) compared to the Standard Point Positioning (SPP) solution. Moreover, it was found that the method can cope successfully in marginal operating conditions with situations of bad satellite geometry and satellite signals affected by interference due to tree canopy.

  13. An efficient and comprehensive method for drainage network extraction from DEM with billions of pixels using a size-balanced binary search tree

    NASA Astrophysics Data System (ADS)

    Bai, Rui; Li, Tiejian; Huang, Yuefei; Li, Jiaye; Wang, Guangqian

    2015-06-01

    With the increasing resolution of digital elevation models (DEMs), computational efficiency problems have been encountered when extracting the drainage network of a large river basin at billion-pixel scales. The efficiency of the most time-consuming depression-filling pretreatment has been improved by using the O(NlogN) complexity least-cost path search method, but the complete extraction steps following this method have not been proposed and tested. In this paper, an improved O(NlogN) algorithm was proposed by introducing a size-balanced binary search tree (BST) to improve the efficiency of the depression-filling pretreatment further. The following extraction steps, including the flow direction determination and the upslope area accumulation, were also redesigned to benefit from this improvement. Therefore, an efficient and comprehensive method was developed. The method was tested to extract drainage networks of 31 river basins with areas greater than 500,000 km2 from the 30-m-resolution ASTER GDEM and two sub-basins with areas of approximately 1000 km2 from the 1-m-resolution airborne LiDAR DEM. Complete drainage networks with both vector features and topographic parameters were obtained with time consumptions in O(NlogN) complexity. The results indicate that the developed method can be used to extract entire drainage networks from DEMs with billions of pixels with high efficiency.

  14. Seasonal changes of surface velocity and elevation of Columbia Glacier, Alaska using time-series TerraSAR-X/TanDEM-X data

    NASA Astrophysics Data System (ADS)

    Vijay, Saurabh; Braun, Matthias

    2015-04-01

    Alaskan glaciers are a major contributor to global sea-level rise from glaciers and ice caps outside the polar ice sheets. Columbia Glacier is a large tidewater glacier located on the coast of south-central Alaska. The glacier has retreated ˜ 21 km and lost half of its volume during 1957-2007, more rapidly after 1980. It is now split into two branches, known as Main/East and West branch. In this study, we used time series of high-resolution TerraSAR-X/TanDEM-X stripmap satellite imagery during 2011-2014 to investigate the temporal development of glacier surface velocities, elevation and mass changes. The active SLC images of the bistatic TanDEM-X acquisitions, acquired over 11 or 22 days repeat intervals, are utilized to derive surface velocity fields using SAR intensity offset tracking. We observed a very strong seasonal variability in the surface velocities. Maximum values at the ice front reach up to 14.43 m/day in May and reduced to 2 m/day in October in the year 2012. However, at a distance of 17.5 km from the ice front, almost no seasonal variability can be observed. A significant influence in the distance to the terminus and elevation was detected. We attributed this temporal and spatial variability of surface velocity to changes in the basal hydrology and lubrification of the glacier bed. Similar fluctuations are observed in consecutive years. In a second step, we exploited TanDEM-X data by interferometrically generating time series of digital elevation models (DEMs) . For quantitative volume change estimates, we used DEMs of almost similar months of the observational years in order to minimize errors resulting from variable X-band radar penetration. The main branch gained a volume of 12.77± 2.89km^3in 2011-12, but lost -18.94± 3.21km^3in 2012-13 . A slight gain was observed with 1.05± .88km^3in 2013-14. However, the west branch gained volume only in 2011-12 and lost in the consecutive years. Moreover, the west branch retreated by ˜ 3km and lost its area twice faster than the main branch during 2011-14.

  15. Yaquina Bay Topobathy DEM

    EPA Science Inventory

    The U.S.EPA contracted with the U.S.ACE to obtain intertidal and subtidal bathymetric soundings of Yaquina Bay between Poole Slough and the South Beach Marina in 2002. These data were compiled with U.S.ACE subtidal soundings from 1999, 1998, 2000 and National Ocean Service soundi...

  16. c Lerche, Uni. Freiburg, 1 Statistik: Zwischen

    E-print Network

    Lerche, Hans Rudolf

    . Datenerhebung #12;c Lerche, Uni. Freiburg, 13 Strittige Sozialstatistiken I. Verbreitung der Prostitution um Prostitution um 1850 in New York a) Sch¨atzung des Bischofs der Methodistenkirche (1866): 11 000 ­ 12 000 b Sozialstatistiken I. Verbreitung der Prostitution um 1850 in New York a) Sch¨atzung des Bischofs der

  17. c Lerche, Uni. Freiburg, 1 Statistik: Zwischen

    E-print Network

    Lerche, Hans Rudolf

    Sozialstatistiken I. Verbreitung der Prostitution um 1850 in New York a) Sch¨atzung des Bischofs der Sozialstatistiken I. Verbreitung der Prostitution um 1850 in New York a) Sch¨atzung des Bischofs der Lerche, Uni. Freiburg, 13 Strittige Sozialstatistiken I. Verbreitung der Prostitution um 1850 in New York

  18. Reevaluation of 1935 M 7.0 earthquake fault, Miaoli-Taichung Area, western Taiwan: a DEM and field study

    NASA Astrophysics Data System (ADS)

    Lin, Y. N.; Chen, Y.; Ota, Y.

    2003-12-01

    A large earthquake (M 7.0) took place in Miaoli area, western Taiwan on April 21st, 1935. Right to its south is the 1999 Chi-Chi earthquake fault, indicating it is not only tectonically but seismically active. As the previous study, the study area is located in the mature zone of a tectonic collision that occurred between Philippine sea Plate and Eurasia continental Plate. The associated surface ruptures of 1935 earthquake daylighted Tungtsichiao Fault, a tear fault trending NE in the south and Chihhu Fault, a back thrust trending N-S in the north, but no ruptures occurred in between. Strike-slip component was identified by the horizontal offset observed along Tungtsichiao Fault; however, there are still disputes on the reported field evidence. Our purposes are (1) to identify the structural behaviors of these two faults, (2) to find out what the seismogenic structure is, and (3) to reconstruct the regional geology by information given by this earthquake. By DEM interpretation and field survey, we can clearly recognize a lot of the 1935 associated features. In the west of Chihhu Fault, a series of N-S higher terraces can be identified with eastward tilted surfaces and nearly 200 m relative height. Another lower terrace is also believed being created during the 1935 earthquake, showing an east-facing scarp with a height of ca. 1.5~2 m. Outcrop investigation reveals that the late-Miocene bedrock has been easterly thrusted over the Holocene conglomerates, indicating a west-dipping fault plane. The Tungtsichiao Fault cuts through a lateritic terrace at Holi, which is supposed developed in Pleistocene. The fault scarp is only discernible in the northeastern ending. Other noticeable features are the fault related antiforms that line up along the surface rupture. There is no outcrop to show the fault geometry among bedrocks. We re-interpret the northern Chihhu Fault as the back thrust generated from a main subsurface detachment, which may be the actual seismogenic fault. Due to the bend geometry normally existing between ramp and detachment, stress accumulated and earthquake happened right on it. The fault tip of this main thrust may be blind on land or break out offshore, which explains why no surface ruptures related to the main thrust were found.

  19. Application of high resolution DEM data to detect rock damage from geomorphic signals along the central San Jacinto Fault

    NASA Astrophysics Data System (ADS)

    Wechsler, Neta; Rockwell, Thomas K.; Ben-Zion, Yehuda

    2009-12-01

    We analyze geomorphic properties extracted from LiDAR and SRTM (Shuttle Radar Topography Mission) data to test whether the damage zone along the central San Jacinto Fault (SJF) zone can be resolved with remotely-sensed data in a quantitative fashion. The SJF is one of the most active faults in southern California, with well expressed geomorphology and a fast slip rate, as seen in the geology and by GPS. We use ArcMap and the TauDEM toolbox to compare several morphometric parameters, including drainage density (Dd), on both sides of the fault, using a 1 km and a 5 km buffer for the LiDAR and SRTM data, respectively. We also analyze the spatial patterns of Dd near the fault, using two different definitions of spatial Dd. The high resolution of the LiDAR data allows us to focus on a single fault, eliminating the effects of parallel nearby faults. From the LiDAR data we find that the highest Dd values occur in areas between two fault strands, followed generally by rocks on the northeast side of the fault, with the lowest Dd values occurring on the southwest side of the fault. The SRTM data shows a band of high Dd values centered on the main fault trace with ~ 1 km width. Our results indicate that there is a strong correlation between drainage density and proximity to the fault, with zones of structural complexity along the fault displaying the highest Dd. We interpret this to largely be an effect of degree of rock damage, as these are areas that are expected to be more damaged, and field observations support this contention. If we are correct, then it appears that the northeast side of the SJF is generally more damaged. South of the trifurcation area there is evidence that the signal is reversed on the larger scale, with more damage on the southwest side of the fault inferred from the SRTM data, possibly caused by extension between the Coyote Creek and Clark faults. The implications of the observed asymmetry could be geological evidence for rupture propagation direction, because a preferred propagation direction is predicted to produce asymmetric damage structure that would be recorded in the volume of rock surrounding a fault.

  20. Photogrammetric Processing of IceBridge DMS Imagery into High-Resolution Digital Surface Models (DEM and Visible Overlay)

    NASA Astrophysics Data System (ADS)

    Arvesen, J. C.; Dotson, R. C.

    2014-12-01

    The DMS (Digital Mapping System) has been a sensor component of all DC-8 and P-3 IceBridge flights since 2009 and has acquired over 3 million JPEG images over Arctic and Antarctic land and sea ice. The DMS imagery is primarily used for identifying and locating open leads for LiDAR sea-ice freeboard measurements and documenting snow and ice surface conditions. The DMS is a COTS Canon SLR camera utilizing a 28mm focal length lens, resulting in a 10cm GSD and swath of ~400 meters from a nominal flight altitude of 500 meters. Exterior orientation is provided by an Applanix IMU/GPS which records a TTL pulse coincident with image acquisition. Notable for virtually all IceBridge flights is that parallel grids are not flown and thus there is no ability to photogrammetrically tie any imagery to adjacent flight lines. Approximately 800,000 Level-3 DMS Surface Model data products have been delivered to NSIDC, each consisting of a Digital Elevation Model (GeoTIFF DEM) and a co-registered Visible Overlay (GeoJPEG). Absolute elevation accuracy for each individual Elevation Model is adjusted to concurrent Airborne Topographic Mapper (ATM) Lidar data, resulting in higher elevation accuracy than can be achieved by photogrammetry alone. The adjustment methodology forces a zero mean difference to the corresponding ATM point cloud integrated over each DMS frame. Statistics are calculated for each DMS Elevation Model frame and show RMS differences are within +/- 10 cm with respect to the ATM point cloud. The DMS Surface Model possesses similar elevation accuracy to the ATM point cloud, but with the following advantages: · Higher and uniform spatial resolution: 40 cm GSD · 45% wider swath: 435 meters vs. 300 meters at 500 meter flight altitude · Visible RGB co-registered overlay at 10 cm GSD · Enhanced visualization through 3-dimensional virtual reality (i.e. video fly-through) Examples will be presented of the utility of these advantages and a novel use of a cell phone camera for aerial photogrammetry will also be presented.

  1. Intercomparison of DEM-based approaches for the identification of flood-prone areas in different geomorphologic and climatic conditions

    NASA Astrophysics Data System (ADS)

    Samela, Caterina; Nardi, Fernando; Grimaldi, Salvatore; De Paola, Francesco; Sole, Aurelia; Manfreda, Salvatore

    2014-05-01

    Floods represent the most critical natural hazard for many countries and their frequency appears to be increasing in recent times. The legal constraints of public administrators and the growing interest of private companies (e.g., insurance companies) in identifying the areas exposed to the flood risk, is determining the necessity of developing new tools for the risk classification over large areas. Nowadays, among the numerous hydrologic and hydraulic methods regularly used for practical applications, 2-D hydraulic modeling represents the most accurate approach for deriving detailed inundation maps. Nevertheless, data requirement for these modeling approaches is certainly onerous, limiting their applicability over large areas. On this issue, the terrain morphology may provide an extraordinary amount of information useful to detect areas that are particularly prone to serious flooding. In the present work, we compare the reliability of different DEM-derived quantitative morphologic descriptors in characterizing the relationships between geomorphic attributes and flood exposure. The tests are carried out using techniques of pattern classification, such as linear binary classifiers (Degiorgis et al., 2012), whose ability is evaluated through performance measures. Simple and composed morphologic features are taken into account. The morphological features are: the upslope contributing area (A), the local slope (S), the length of the path that hydrologically connects the location under exam to the nearest element of the drainage network (D), the difference in elevation between the cell under exam and the final point of the same path (H), the curvature (downtriangle2H). In addition to the mentioned features, the study takes into consideration a number of composed indices, such as: the modified topographic index (Manfreda et al., 2011), the downslope index (DI) proposed by Hjerdt et al. (2004), the ratio between the elevation difference H and the distance to the network D, and other indices. Each binary classifier is applied in several catchments in order to verify the reproducibility of the procedures in different geomorphologic, climatic and hydrologic conditions. The study explores the use of these procedures in gauged river basins located in Italy and in an ungauged basin located in Africa. References Degiorgis, M., G. Gnecco, S. Gorni, G. Roth, M. Sanguineti, A.C. Taramasso, 2012. Classifiers for the detection of flood-prone areas using remote sensed elevation data, J. Hydrol., 470-471, 302-315. Hjerdt, K. N., J.J. McDonnell, J. Seibert, A. Rodhe, A new topographic index to quantify downslope controls on local drainage, Water Resour. Res., 40, W05602, 2004. Manfreda, S., M. Di Leo, A. Sole, Detection of Flood Prone Areas using Digital Elevation Models, J. Hydrol. Eng., 16(10), 781-790, 2011.

  2. Study of Morphologic Change in Poyang Lake Basin Caused by Sand Dredging Using Multi-temporal Landsat Images and DEMs

    NASA Astrophysics Data System (ADS)

    Qi, S.; Zhang, X.; Wang, D.; Zhu, J.; Fang, C.

    2014-11-01

    Sand dredging has been practiced in rivers, lakes, harbours and coastal areas in recent years in China mostly because of demand from construction industry as building material. Sand dredging has disturbed aquatic ecosystems by affecting hydrological processes, increasing content of suspended sediments and reducing water clarity. Poyang Lake, connecting with Yangtze River in the lower reaches of the Yangtze River, is the largest fresh water lake in China. Sand dredging in Poyang Lake has been intensified since 2001 because such practice was banned in Yangtze River and profitable. In this study, the morphologic change caused by sand dredging in Poyang Lake basin was analysed by overlaying two DEMs acquired in 1952 and 2010 respectively. Since the reflectance of middle infrared band for sand dredging vessel is much higher than that of water surface, sand dredging vessels were showed as isolated grey points and can be counted in the middle infrared band in 12 Landsat images acquired in flooding season during 2000~2010. Another two Landsat images (with low water level before 2000 and after 2010) were used to evaluate the morphologic change by comparing inundation extent and shoreline shape. The following results was obtained: (1) vessels for sand dredging are mainly distributed in the north of Poyang Lake before 2007, but the dredging area was enlarged to the central region and even to Gan River; (2) sand dredging area reached to about 260.4 km2 and is mainly distributed in the north of Songmen Mountain and has been enlarged to central of Poyang Lake from the distribution of sand vessels since 2007. Sand dredged from Poyang Lake was about 1.99 × 109 m3 or 2448 Mt assuming sediment bulk density of 1.23 t m-3. It means that the magnitude of sand mining during 2001-2010 is almost ten times of sand depositions in Poyang Lake during 1955-2010; (3) Sand dredging in Poyang Lake has alternated the lake capacity and discharge section area, some of the watercourse in the northern channel was enlarged by more than 1 km when in low lake level. This study is useful to understand the change of hydrological system, especially the drying up trend in Poyang Lake in recent autumns and winters.

  3. Tracking and evolution of irrigation triggered active landslides by multi-source high resolution DEM: The Jiaojiacun landslide group of Heifangtai (Northwest of China)

    NASA Astrophysics Data System (ADS)

    Zeng, Runqiang; Meng, Xingmin; Wang, Siyuan; Chen, Guan; Lee, Yajun; Zhang, Yi

    2014-05-01

    The construction of three large hydropower stations, i.e. Liujia, Yanguo and Bapan, resulted in the immigration of the impacted people to Heifangtai from 1960s. To support the living and farming of the immigrated people, a large amount of water has been pumped from the Yellow River to Heifangtai, which has changed the former underground water budget and led to 111 landslides from 1968 in this area. To reveal the deformation process of landslides in Heifangtai, a quantitative deformation analysis model of landslide based on multi-source DEM data is established using four periods of topographic maps obtained in 1970, 2001, 2010 and 2013 respectively, including two 1:10000 topographic maps and two 1:1000 data acquired from 3D Laser Scanner. The whole study area was divided into two sections based on the two distinct kinds of landslide patterns. The selected morphometric parameters, residual topographic surface and surface roughness, extracted from three typical landslides, and the statistical analysis (Box-plot diagrams) of the temporal variations of these parameters, allowed the reconstruction and tracking of these landslides. We monitored the changing of landslide boundaries, average vertical and horizontal displacement rates and zones of uplift and subsidence. The volumes of removed and/or accumulated material were estimated as well. We can then demonstrate the kinematics of landslides based on information from high-resolution DEM, and the changing table of underground water, ring-shear test and soil-water characteristic curve referenced from other researchers. The results provide a new insight on the use of multi-source high resolution DEM in the monitoring of irrigation-triggered landslides.

  4. The Multi-Instrument (EVE-RHESSI) DEM for Solar Flares, and Implications for Residual Non-Thermal Soft X-Ray Emission

    NASA Astrophysics Data System (ADS)

    McTiernan, James M.; Caspi, Amir; Warren, Harry

    2015-04-01

    In the soft X-ray energy range, solar flare spectra are typically dominated by thermal emission. The low energy extent of non-thermal emission can only be loosely quantified using currently available X-ray data. To address this issue, we combine observations from the EUV Variability Experiment (EVE) on-board the Solar Dynamics Observatory (SDO) with X-ray data from the Reuven Ramaty High Energy Spectroscopic Imager (RHESSI). The improvement over the isothermal approximation is intended to resolve the ambiguity in the range where the thermal and non-thermal components may have similar photon fluxes. This "crossover" range can extend up to 30 keV for medium to large solar flares.Previous work (Caspi et.al. 2014ApJ...788L..31C) has concentrated on obtaining DEM models that fit both instruments' observations well. Now we are interested in any breaks and cutoffs in the "residual" non-thermal spectrum; i.e., the RHESSI spectrum that is left over after the DEM has accounted for the bulk of the soft X-ray emission. Thermal emission is again modeled using a DEM that is parametrized as multiple gaussians in temperature; the non-thermal emission is modeled as a photon spectrum obtained using a thin-target emission model ('thin2' from the SolarSoft Xray IDL package). Spectra for both instruments are fit simultaneously in a self-consistent manner. The results for non-thermal parameters then are compared with those found using RHESSI data alone, with isothermal and double-thermal models.

  5. Neural correlates of the DemTect in Alzheimer's disease and frontotemporal lobar degeneration – A combined MRI & FDG-PET study?

    PubMed Central

    Woost, Timo B.; Dukart, Juergen; Frisch, Stefan; Barthel, Henryk; Sabri, Osama; Mueller, Karsten; Schroeter, Matthias L.

    2013-01-01

    Valid screening devices are critical for an early diagnosis of dementia. The DemTect is such an internationally accepted tool. We aimed to characterize the neural networks associated with performance on the DemTect's subtests in two frequent dementia syndromes: early Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD). Voxel-based group comparisons of cerebral glucose utilization (as measured by F-18-fluorodeoxyglucose positron emission tomography) and gray matter atrophy (as measured by structural magnetic resonance imaging) were performed on data from 48 subjects with AD (n = 21), FTLD (n = 14) or subjective cognitive impairment (n = 13) as a control group. We performed group comparisons and correlation analyses between multimodal imaging data and performance on the DemTect's subtests. Group comparisons showed regional patterns consistent with previous findings for AD and FTLD. Interestingly, atrophy dominated in FTLD, whereas hypometabolism in AD. Across diagnostic groups performance on the “wordlist” subtest was positively correlated with glucose metabolism in the left temporal lobe. The “number transcoding” subtest was significantly associated with glucose metabolism in both a predominantly left lateralized frontotemporal network and a parietooccipital network including parts of the basal ganglia. Moreover, this subtest was associated with gray matter density in an extensive network including frontal, temporal, parietal and occipital areas. No significant correlates were observed for the “supermarket task” subtest. Scores on the “digit span reverse” subtest correlated with glucose metabolism in the left frontal cortex, the bilateral putamen, the head of caudate nucleus and the anterior insula. Disease-specific correlation analyses could partly verify or extend the correlates shown in the analyses across diagnostic groups. Correlates of gray matter density were found in FTLD for the “number transcoding” subtest and the “digit span reverse” subtest. Correlates of glucose metabolism were found in AD for the “wordlist” subtest and in FTLD for the “digit span reverse” subtest. Our study contributes to the understanding of the neural correlates of cognitive deficits in AD and FTLD and supports an external validation of the DemTect providing preliminary conclusions about disease-specific correlates. PMID:24179826

  6. Neural correlates of the DemTect in Alzheimer's disease and frontotemporal lobar degeneration - A combined MRI & FDG-PET study.

    PubMed

    Woost, Timo B; Dukart, Juergen; Frisch, Stefan; Barthel, Henryk; Sabri, Osama; Mueller, Karsten; Schroeter, Matthias L

    2013-01-01

    Valid screening devices are critical for an early diagnosis of dementia. The DemTect is such an internationally accepted tool. We aimed to characterize the neural networks associated with performance on the DemTect's subtests in two frequent dementia syndromes: early Alzheimer's disease (AD) and frontotemporal lobar degeneration (FTLD). Voxel-based group comparisons of cerebral glucose utilization (as measured by F-18-fluorodeoxyglucose positron emission tomography) and gray matter atrophy (as measured by structural magnetic resonance imaging) were performed on data from 48 subjects with AD (n = 21), FTLD (n = 14) or subjective cognitive impairment (n = 13) as a control group. We performed group comparisons and correlation analyses between multimodal imaging data and performance on the DemTect's subtests. Group comparisons showed regional patterns consistent with previous findings for AD and FTLD. Interestingly, atrophy dominated in FTLD, whereas hypometabolism in AD. Across diagnostic groups performance on the "wordlist" subtest was positively correlated with glucose metabolism in the left temporal lobe. The "number transcoding" subtest was significantly associated with glucose metabolism in both a predominantly left lateralized frontotemporal network and a parietooccipital network including parts of the basal ganglia. Moreover, this subtest was associated with gray matter density in an extensive network including frontal, temporal, parietal and occipital areas. No significant correlates were observed for the "supermarket task" subtest. Scores on the "digit span reverse" subtest correlated with glucose metabolism in the left frontal cortex, the bilateral putamen, the head of caudate nucleus and the anterior insula. Disease-specific correlation analyses could partly verify or extend the correlates shown in the analyses across diagnostic groups. Correlates of gray matter density were found in FTLD for the "number transcoding" subtest and the "digit span reverse" subtest. Correlates of glucose metabolism were found in AD for the "wordlist" subtest and in FTLD for the "digit span reverse" subtest. Our study contributes to the understanding of the neural correlates of cognitive deficits in AD and FTLD and supports an external validation of the DemTect providing preliminary conclusions about disease-specific correlates. PMID:24179826

  7. Performance Evaluation of Four DEM-Based Fluvial Terrace Mapping Methods Across Variable Geomorphic Settings: Application to the Sheepscot River Watershed, Maine

    NASA Astrophysics Data System (ADS)

    Hopkins, A. J.; Snyder, N. P.

    2014-12-01

    Fluvial terraces are utilized in geomorphic studies as recorders of land-use, climate, and tectonic history. Advances in digital topographic data, such as high-resolution digital elevation models (DEMs) derived from airborne lidar surveys, has promoted the development of several methods used to extract terraces from DEMs based on their characteristic morphology. The post-glacial landscape of the Sheepscot River watershed, Maine, where strath and fill terraces are present and record Pleistocene deglaciation, Holocene eustatic forcing, and Anthropocene land-use change, was selected to implement a comparison between terrace mapping methodologies. At four study sites within the watershed, terraces were manually mapped to facilitate the comparison between fully and semi-automated DEM-based mapping procedures, including: (1) edge detection functions in Matlab, (2) feature classification algorithms developed by Wood (1996), (3) spatial relationships between interpreted terraces and surrounding topography (Walter et al., 2007), and (4) the TerEx terrace mapping toolbox developed by Stout and Belmont (2014). Each method was evaluated based on its accuracy and ease of implementation. The four study sites have varying longitudinal slope (0.1% - 5%), channel width (<5 m - 30 m), relief in surrounding landscape (15 m - 75 m), type and density of surrounding land use, and mapped surficial geologic units. In general, all methods overestimate terrace areas (average predicted area 136% of the manually defined area). Surrounding topographic relief appears to exert the greatest control on mapping accuracy, with the most accurate results (92% of terrace area mapped by Walter et al., 2007 method) achieved where the river valley was most confined by adjacent hillslopes. Accuracy decreased for study sites surrounded by a low-relief landscape, with the most accurate results achieved by the TerEx toolbox (Stout and Belmont, 2014; predicted areas were 45% and 89% of manual delineations). Our work informs future studies by highlighting the strengths and drawbacks of each method tested and by making recommendations for the types of geomorphic settings where each is most appropriate. The tested algorithms represent powerful new ways to analyze landscape history over large regions using high-resolution, lidar DEMs.

  8. Mass changes of glaciers over the Central Karakoram derived from TanDEM-X and SRTM/X-SAR Digital Elevation Models

    NASA Astrophysics Data System (ADS)

    Rankl, Melanie; Braun, Matthias

    2015-04-01

    Snow cover and glaciers in the Karakoram region are important freshwater resources for many downriver communities as they provide water for irrigation and hydro power. A better understanding of current glacier changes is hence an important baseline information. Glaciers in the Karakoram have shown stable and positive glacier mass balances during recent years as well as stable and advancing termini positions. The Karakoram is also known for a large number of surge-type glaciers. Here, we present geodetic glacier elevation and mass changes using TanDEM-X and SRTM/X-SAR Digital Elevation Models between 2000 and 2012. Based on previous glacier inventories for the Karakoram, we show elevation changes and glacier mass balances for glaciers with advancing and stable termini between 2000 and 2012 as well as surge-type glaciers separately. In order to convert volume changes to mass changes, we applied different density scenarios (i.e., constant densities for ice and snow or zonally variable densities). Our findings show average glacier thickening of +0.01 ± 0.02 m a-1 or mass gain of +0.0099 ± 2.8x10-5 Gt a-1(using a density of 850 kg m-3) between 2000 and 2012 for parts of the Central Karakoram. Surge-type glaciers and advancing glaciers indicated slight surface lowering, while the majority of the studied glaciers showed stable termini and surface thickening. Our measurements are independent from varying penetration depths of the radar signal or temporal decorrelation between image acquisitions. Both datasets were acquired in the X-band frequency under assumed similar surface conditions. The bistatic TanDEM-X mission is highly suitable for interferometric processing due to high spatial resolutions and only 3 sec time lag between TanDEM-X and TerraSAR-X overpasses. We want to stress the enormous potential of the TanDEM-X mission to estimate geodetic glacier mass balances, in particular when compared to elevation data sets acquired in a similar frequency and comparable observation period.

  9. SMS1 fur MC, FHS Hagenberg 12. Ubungsblatt fur den 19. Janner 2006

    E-print Network

    ) Worauf mussen sich Alice und Bob im Setup einigen? (b) Welche Nachrichten werden ausgetauscht? (c) Wie zwischen Alice und Bob ausgetauschten Nachrichten kennt? 4. Alice und Sie wollen sich mit dem Verfahren von

  10. Using the ASTER global DEM to derive empirical relationships among triangular facet slope, facet height and slip rates along active normal faults

    NASA Astrophysics Data System (ADS)

    Tsimi, Christina; Ganas, Athanassios

    2015-04-01

    The advent of global DEMs provided a uniform elevation dataset for studying geomorphic parameters in a variety of settings. In this paper ASTER DEM data (30-m pixel size) are used to derive empirical relationships between triangular facet attributes and slip rates along active normal faults. We sampled 232 triangular facets along 10 normal faults in Greece and Bulgaria that slip with rates from 0.1 mm/yr up to 1.3 mm/yr. The studied normal faults accumulate Quaternary tectonic strain in well-known extensional provinces, such as central Greece, Crete and SW Bulgaria. The normal fault footwalls analyzed herein have been developed under similar long-term climatic conditions. It is suggested that two key geometrical features of the youngest generation of triangular facets (slope angle and height) can provide useful metrics to assess rates of deformation when seismological and geodetic data are lacking or not found in sufficient quantity to make reasonable assessments. Our derived empirical relation between slip rate and facet slope angle is: Y = 0.057 × X - 1 where Y is the fault slip rate (mm/yr) and X is the facet slope angle (degrees), with an R2 = 0.728. It is envisaged that our analysis may be helpful in assessing seismic hazard along normal faults with similar facet characteristics in other extensional settings.

  11. A GIS modeled DEM-based hydrologic watershed network of the Greenland Ice Sheet and non-ice land surface areas

    NASA Astrophysics Data System (ADS)

    Pitcher, L. H.; Smith, L. C.; Chu, V. W.; Wang, J.

    2011-12-01

    Increased mass loss of the Greenland Ice Sheet and subsequent global sea level rise has amplified the need to understand Greenland's hydrology and melt patterns. Drainage basins for Greenland's land surface and ice sheet were produced using the GLAS/IceSat 1km surface DEM and a hydrostatic surface pressure grid over the ice sheet. The pressure grid was modeled using the surface DEM and a 5km bedrock elevation grid (Bamber et al., 2001), assuming hydrostatic pressure and no conduit flow within the ice sheet as per Lewis & Smith (2009). Pour points were generated using an 8-pixel pour point derivation algorithm (Jenson & Domingue, 1988) and were used to model watersheds and flow networks. This work provides a complete watershed, flow and drainage network dataset for the entirety of Greenland - both land and ice surface regions. Potential applications include ice sheet melt water routing to the ocean, supraglacial melt water patterns, and the separation of specific ice melt drainage networks from snow melt networks. These basins act as a base for the incorporation of finer resolution IceBridge and GLAS/IceSat data products.

  12. Co-seismic vertical displacements from a single post-seismic lidar DEM: example from the 2010 El Mayor-Cucapah earthquake

    NASA Astrophysics Data System (ADS)

    Barišin, Ivana; Hinojosa-Corona, Alejandro; Parsons, Barry

    2015-07-01

    A method is outlined by means of which it is possible to estimate high-resolution vertical displacements due to an earthquake even in the case where high-resolution topography is lacking before the earthquake. This result can be achieved by combining a highly accurate, post-event digital elevation model (DEM), for example lidar, with archived satellite imagery. The method is illustrated by calculating vertical displacements for the 2010 El Mayor-Cucapah earthquake. For this earthquake, there are both pre- and post-event lidar DEMs from which vertical displacements may also be estimated after correcting for the lateral advection of topography due to horizontal displacements. A comparison between the two means of deriving vertical displacements shows generally good agreement, with the displacements obtained using satellite imagery performing better in high relief areas. As a result of this property, we are able to trace the vertical offsets due to the El Mayor-Cucapah earthquake as the rupture jumped from the Pescadores fault to the Borrego fault in propagating through the high relief of the Sierra Cucapah.

  13. A new set of MATLAB functions (TecDEM toolbox) to analyze erosional stages in landscapes and base-level changes in river profiles

    NASA Astrophysics Data System (ADS)

    Andreani, Louis; Gloaguen, Richard; Shahzad, Faisal

    2014-05-01

    We implemented three new functions in the MATLAB-based TecDEM toolbox [1,2]: surface index, topographic position index, and the analysis of base-levels in river longitudinal profiles. These tools provide useful ways to understand the effects of base-level changes on topography such as stream captures, erosion or rejuvenation of pre-existing topographic features and anomalies in river longitudinal profiles. We developed a new index (referred as "surface index") which provides a quick way to map simultaneously preserved and eroded portions of an elevated landscape. This index classifies landscapes according to their erosional stages using the combination of the hypsometric integral, which efficiently highlights flat surfaces, and the surface roughness, which substantially increases with incision. We also implemented the commonly used "topographic position index". This index provides a simple way to classify the landscapes as valleys, ridges and flat areas. However, its application in tectonic geomorphology can go far beyond as it discriminates valleys shapes and reveals other important features such as wind gaps and knickpoints when associated to the extracted river system. Finally, we implemented a tool allowing the estimation of base-level changes using the reconstruction of river longitudinal profiles. River profiles can be decomposed in concave or convex segments. Relict base-levels are typically associated to gently concave segments in river profiles. By restoring the initial shape of these segments we are able to estimate the amount of incision between the present day base-level and the relict base-level. All these tools were successfully tested in different settings such as Central America, Central Europe and Pamir. In addition to the description of these tools we provide examples from these different areas. [1] Shahzad, F., & Gloaguen, R. (2011). TecDEM: A MATLAB based toolbox for tectonic geomorphology, Part 1: Drainage network preprocessing and stream profile analysis. Computers & Geosciences, 37, 250-260. [2] Shahzad, F., & Gloaguen, R. (2011). TecDEM: A MATLAB based toolbox for tectonic geomorphology, Part 2: Surface dynamics and basin analysis. Computers & Geosciences, 37, 261-271.

  14. Testing the influence of vertical, pre-existing joints on normal faulting using analogue and 3D discrete element models (DEM)

    NASA Astrophysics Data System (ADS)

    Kettermann, Michael; von Hagke, Christoph; Virgo, Simon; Urai, Janos L.

    2015-04-01

    Brittle rocks are often affected by different generations of fractures that influence each other. We study pre-existing vertical joints followed by a faulting event. Understanding the effect of these interactions on fracture/fault geometries as well as the development of dilatancy and the formation of cavities as potential fluid pathways is crucial for reservoir quality prediction and production. Our approach combines scaled analogue and numerical modeling. Using cohesive hemihydrate powder allows us to create open fractures prior to faulting. The physical models are reproduced using the ESyS-Particle discrete element Modeling Software (DEM), and different parameters are investigated. Analogue models were carried out in a manually driven deformation box (30x28x20 cm) with a 60° dipping pre-defined basement fault and 4.5 cm of displacement. To produce open joints prior to faulting, sheets of paper were mounted in the box to a depth of 5 cm at a spacing of 2.5 cm. Powder was then sieved into the box, embedding the paper almost entirely (column height of 19 cm), and the paper was removed. We tested the influence of different angles between the strike of the basement fault and the joint set (0°, 4°, 8°, 12°, 16°, 20°, and 25°). During deformation we captured structural information by time-lapse photography that allows particle imaging velocimetry analyses (PIV) to detect localized deformation at every increment of displacement. Post-mortem photogrammetry preserves the final 3-dimensional structure of the fault zone. We observe that no faults or fractures occur parallel to basement-fault strike. Secondary fractures are mostly oriented normal to primary joints. At the final stage of the experiments we analyzed semi-quantitatively the number of connected joints, number of secondary fractures, degree of segmentation (i.e. number of joints accommodating strain), damage zone width, and the map-view area fraction of open gaps. Whereas the area fraction does not change distinctly, the number of secondary fractures and connected joints increases strongly with increasing angles between basement fault and joint strike. Integrating these models with a 3-dimensional DEM code using the ESyS-Particle software allows for retrieving 4D information from the models, as well as for testing other parameters such as joint spacing or joint depth. Our DEM models are capable of robustly reproducing all characteristic features observed in the analogue models, and will provide a quantitative measure of the influence of joint-fault angle on permeability of cohesive rocks that have experienced more than one brittle deformation phase.

  15. Full-waveform and discrete-return lidar in salt marsh environments: An assessment of biophysical parameters, vertical uncertatinty, and nonparametric dem correction

    NASA Astrophysics Data System (ADS)

    Rogers, Jeffrey N.

    High-resolution and high-accuracy elevation data sets of coastal salt marsh environments are necessary to support restoration and other management initiatives, such as adaptation to sea level rise. Lidar (light detection and ranging) data may serve this need by enabling efficient acquisition of detailed elevation data from an airborne platform. However, previous research has revealed that lidar data tend to have lower vertical accuracy (i.e., greater uncertainty) in salt marshes than in other environments. The increase in vertical uncertainty in lidar data of salt marshes can be attributed primarily to low, dense-growing salt marsh vegetation. Unfortunately, this increased vertical uncertainty often renders lidar-derived digital elevation models (DEM) ineffective for analysis of topographic features controlling tidal inundation frequency and ecology. This study aims to address these challenges by providing a detailed assessment of the factors influencing lidar-derived elevation uncertainty in marshes. The information gained from this assessment is then used to: 1) test the ability to predict marsh vegetation biophysical parameters from lidar-derived metrics, and 2) develop a method for improving salt marsh DEM accuracy. Discrete-return and full-waveform lidar, along with RTK GNSS (Real-time Kinematic Global Navigation Satellite System) reference data, were acquired for four salt marsh systems characterized by four major taxa (Spartina alterniflora, Spartina patens, Distichlis spicata, and Salicornia spp.) on Cape Cod, Massachusetts. These data were used to: 1) develop an innovative combination of full-waveform lidar and field methods to assess the vertical distribution of aboveground biomass as well as its light blocking properties; 2) investigate lidar elevation bias and standard deviation using varying interpolation and filtering methods; 3) evaluate the effects of seasonality (temporal differences between peak growth and senescent conditions) using lidar data flown in summer and spring; 4) create new products, called Relative Uncertainty Surfaces (RUS), from lidar waveform-derived metrics and determine their utility; and 5) develop and test five nonparametric regression model algorithms (MARS -- Multivariate Adaptive Regression, CART -- Classification and Regression Trees, TreeNet, Random Forests, and GPSM -- Generalized Path Seeker) with 13 predictor variables derived from both discrete and full waveform lidar sources in order to develop a method of improving lidar DEM quality. Results of this study indicate strong correlations for Spartina alterniflora (r > 0.9) between vertical biomass (VB), the distribution of vegetation biomass by height, and vertical obscuration (VO), the measure of the vertical distribution of the ratio of vegetation to airspace. It was determined that simple, feature-based lidar waveform metrics, such as waveform width, can provide new information to estimate salt marsh vegetation biophysical parameters such as vegetation height. The results also clearly illustrate the importance of seasonality, species, and lidar interpolation and filtering methods on elevation uncertainty in salt marshes. Relative uncertainty surfaces generated from lidar waveform features were determined useful in qualitative/visual assessment of lidar elevation uncertainty and correlate well with vegetation height and presence of Spartina alterniflora. Finally, DEMs generated using full-waveform predictor models produced corrections (compared to ground based RTK GNSS elevations) with R2 values of up to 0.98 and slopes within 4% of a perfect 1:1 correlation. The findings from this research have strong potential to advance tidal marsh mapping, research and management initiatives.

  16. Measuring the quality of life of people with dementia in nursing homes in Germany – the study protocol for the Qol-Dem Project

    PubMed Central

    Dichter, Martin Nikolaus; Halek, Margareta; Dortmann, Olga; Meyer, Gabriele; Bartholomeyczik, Sabine

    2013-01-01

    Background: QUALIDEM is a standardized dementia-specific quality of life (Qol) measurement, which was developed and validated in the Netherlands. A German version has been available since 2008. This study protocol describes the design and methodology for the quality of life of people with dementia (Qol-Dem) project. Objective: This project aims to evaluate the reliability and validity of the German version of the QUALIDEM. Method: Due to the lack of both a universal definition of Qol and of standards to verify the validity of Qol measurements, this study is divided into three phases. The aim of the first theoretical phase is the development of a dementia-specific Qol model as a result of a meta-synthesis of qualitative studies. The second empirical phase consists of the three following steps: (a) an investigation of the scalability and internal consistency of the measure, (b) an evaluation of the interrater and intrarater reliability, and (c) an extensive evaluation of the validity of the QUALIDEM. The resulting Qol model (phase 1) will be used for the selection of appropriate comparators for validity testing. In the third phase, the QUALIDEM will be adapted, if necessary, based on the knowledge generated in the first two phases. Conclusion: The findings of the Qol-Dem project should deliver an accurate assessment of the psychometric properties of the German version of the QUALIDEM. The results will contribute to the further development of the instrument. Furthermore, the results will contribute to the theoretical development of the concept of Qol among people with dementia. PMID:23922616

  17. Development of Flood Inundation Libraries using Historical Satellite Data and DEM for Part of Godavari Basin: An Approach Towards Better Flood Management

    NASA Astrophysics Data System (ADS)

    Bhatt, C. M.; Rao, G. S.; Patro, B.

    2014-12-01

    Conventional method of identifying areas to be inundated for issuing flood alert require inputs like discharge data, fine resolution digital elevation model (DEM), software for modelling and technically trained manpower to interpret the results meaningfully. Due to poor availability of these inputs, including good network of historical hydrological observations and limitation of time, quick flood early warning becomes a difficult task. Presently, based on the daily river water level and forecasted water level for major river systems in India, flood alerts are provided which are non-spatial in nature and does not help in understanding the inundation (spatial dimension) which may be caused at various water levels. In the present paper a concept for developing a series of flood-inundation map libraries two approaches are adopted one by correlating inundation extent derived from historical satellite data analysis with the corresponding water level recorded by the gauge station and the other simulation of inundation using digital elevation model (DEM's) is demonstrated for a part of Godavari Basin. The approach explained can be one of quick and cost-effective method for building a library of flood inundation extents, which can be utilized during flood disaster for alerting population and taking the relief and rescue operations. This layer can be visualized from a spatial dimension together with other spatial information like administrative boundaries, transport network, land use and land cover, digital elevation data and satellite images for better understanding and visualization of areas to be inundated spatially on free web based earth visualization portals like ISRO's Bhuvan portal (http://bhuvan.nrsc.gov.in). This can help decision makers in taking quick appropriate measures for warning, planning relief and rescue operations for the population to get affected under that river stage.

  18. Tectonic architecture through Landsat-7 ETM+/SRTM DEM-derived lineaments and relationship to the hydrogeologic setting in Siwa region, NW Egypt

    NASA Astrophysics Data System (ADS)

    Masoud, Alaa; Koike, Katsuaki

    2006-08-01

    Fracture zones on the Earth's surface are important elements in the understanding of plate motion forces, the dynamics of the subsurface fluid flow, and earthquake distributions. However, good exposures of these features are always lacking in arid regions, characterized by flat topography and where sand dunes extensively cover the terrain. During field surveys these conditions, in many cases, hinder the proper characterization of such features. Therefore, an approach that identifies the regional fractures as lineaments on remotely-sensed images or shaded digital terrain models, with its large scale synoptic coverage, could be promising. In the present work, a segment tracing algorithm (STA), for lineament detection from Landsat-7 Enhanced Thematic Mapper Plus (ETM+) imagery, and the data from the Shuttle Radar Topographic Mission (SRTM) 30 m digital elevation model (DEM), has been applied in the Siwa region, located in the northwest of the Western Desert of Egypt. The objectives are to analyze the spatial variation in orientation of the detected linear features and its relation to the hydrogeologic setting in the area and the underlying geology, and to evaluate the performance of the algorithm applied to the ETM+ and the DEM data. Detailed structural analysis and better understanding of the tectonic evolution of the area could provide useful tools for hydrologists for reliable groundwater management and development planning. The results obtained have been evaluated by the structural analysis of the area and field observations. Four major vertical fracture zones were detected corresponding to two conjugate sets of strike-slip faults that governed the surface, and subsurface environments of the lakes in the region, and these correlate well with the regional tectonics.

  19. Geoinformatik: Modelle, Strukturen, Funktionen

    NASA Astrophysics Data System (ADS)

    Bartelme, Norbert

    Ob im Alltag oder bei Fachfragen - wir begründen Entscheidungen nicht nur inhaltlich, sondern auch nach dem räumlichen und zeitlichen Zusammenhang. Die Geoinformation bietet Antwort auf beide Fragen. 'Geoinformatik' vermittelt einen breiten Überblick über die Modellierung von Geoinformation in Datenbanken und informationsverarbeitenden Systemen. Das Spektrum reicht von der Modellierung von Geo-Objekten im Raum biszu ihrer Schematisierung in Datenbanken vor dem Hintergrund typischer GIS-Applikationen.

  20. On the investigation of the performances of a DEM-based hydrogeomorphic floodplain identification method in a large urbanized river basin: the Tiber river case study in Italy

    NASA Astrophysics Data System (ADS)

    Nardi, Fernando; Biscarini, Chiara; Di Francesco, Silvia; Manciola, Piergiorgio

    2013-04-01

    Floodplains are critical landscape features for their importance in both ecohydrological and socio-economic terms. River valleys are, in fact, the domain where the interdependence of the complex human-environmental interface is more significant. Riparian zones, along perennial channels, where the frequency of saturation is high and most flooding occurs, are also the areas where urban areas and infrastructures (e.g. highways, bridges, railways, etc) are more present. This is mainly due to geomorphologic conditions since those areas are predominantly flat and easier to develop. One of the more challenging issues under changing climatic, environmental and human drivers for implementing efficient current and future urban plans is to accurately and timely identify, map and characterize the potential flooding scenarios of floodplains. This is currently achieved by implementing detailed topographic, hydrologic and hydraulic studies for flood modeling and mapping for different frequencies (i.e. return time), but those activities are rarely implemented at the large (river basin) scale for their economic cost and time of implementation. In addition to that, flood map updating is not as frequent as needed for following the rapid changing land use conditions. As a result, it is very often the case that urban plans are based on heterogeneous and discontinuous flood map information. Nevertheless, several recent researches demonstrated the potential for the use of high resolution digital elevation models (DEMs) to define the floodplain feature by means of automated hydrogeomorphic methods. This means identifying the flood prone area by filtering potentially inundated cells by implementing proper morphological and hydrological analyses. In this work we implemented the flooplain identification model proposed by Nardi et al. (WRR, 2006) which automatically extract the river network and estimate flood water levels according to a predefined scaling Leopold law. Inundated areas are consequently identified as those river buffers, draining towards the channel, with an elevation that is less than the maximum flow depth of the corresponding outlet. Keeping in mind that this hydrogeomorhic model performances are strictly related to the quality and properties of the input DEM and that the intent of this kind of methodology is not to substitute standard flood modeling and mapping methods, in this work the performances of this approach are qualitatively evaluated by comparing results with standard flood maps. The Tiber river basin was selected as case study, one of the main river basins in Italy covering a drainage area of approximately 17.000 km2. This comparison is interesting for understanding the performance of the model in a large and complex domain where the impact of the urbanization matrix is significant. Results of this investigation confirm the potential of such DEM-based floodplain mapping models for providing a fast timely homogeneous and continuous inundation scenario to urban planners and decision makers, but also the drawbacks of using such methodology where the humans are significantly and rapidly modifying the surface properties.

  1. Morphotectonics inferred from the analysis of topographic lineaments auto-detected from DEMs: Application and validation for the Sinai Peninsula, Egypt

    NASA Astrophysics Data System (ADS)

    Masoud, Alaa A.; Koike, Katsuaki

    2011-10-01

    Morphotectonic lineaments observed on the Sinai Peninsula in Egypt were auto-detected from Shuttle Radar Topography Mission 90-m digital elevation model (DEM) and gravity grid data and then analyzed to characterize the tectonic trends that dominated the geologic evolution of this area. The approach employed consists of DEM shading, segment tracing, grouping, statistical analysis of the distribution and orientation of the lineaments, fault plane characterization, and smooth representation techniques. Statistical quantification of counts, mean lengths, densities, and orientations was used to infer the relative severity of the tectonic regimes, to unravel the prominent structural trends, and to demarcate the contribution of various faulting styles that prevailed through time. Restored to the present-day geographic position, prominent N50°-60°W, N20°-40°W, N50°-60°E, and N20°-30°E and less prominent N-S, E-W, and ENE trends were common. The prominence of these trends varied through time. The NW and NE trends showed relatively equal abundances in the Precambrian and the Cambrian whereas the prominence of the NW trends prevailed from the Carboniferous to the Holocene. Lineaments in all formations were near vertical and on average, about 65% showed as strike-slip, 22% as reverse, and 13% as normal faulting styles. Statistics from the detected linear features and the reference geological data reveal the relative severity of five dominant tectonic regimes: Precambrian compression followed by extension at its end, Cretaceous compression, Eocene compression, Miocene extension, and finally Holocene compression. Auto-detected lineaments and the severity of the characterized tectonic periods correspond well with reference data on the geologic structure, geodynamic framework, and the gravity anomaly. Furthermore, the recent significance of the broad structural zones was confirmed by the foci of the earthquake epicenters along and at the intra-plate intersections of the broad lineament zones and at the plate boundaries. The spatial distribution of trends with varying styles of faulting distinguished four main tectonic provinces of marked geodynamics variances.

  2. Constraining the DEM and the kinematics of an unstable slope in the Maurienne Valley (French Alps) from remote and ground optical techniques

    NASA Astrophysics Data System (ADS)

    Valentin, Johann; Donze, Frédéric; Jongmans, Denis; Yvart, Sébastien; Lacroix, Pascal; Brenguier, Ombeline; Baillet, Laurent; Lescurier, Anne; Muller, Nicolas; Larose, Eric

    2015-04-01

    Clay-rich rocks are abundant in the Alps where they make a significant part of the sedimentary cover. When they are exposed, these rocks may form reliefs that are affected by rock falls. The failed material quickly transform into rock debris with a fine-grained matrix, which accumulates on slope and in gullies. Historical chronicles show that devastating debris flows can be triggered in the Alpine valleys in case of heavy rain falls. An unstable slope located in the Flysch zone (of Eocene age) has been chosen in the Maurienne valley (French Alps), which is 1 km wide at this location. The study area (0.3 km2) exhibits a rough topography with a slope varying between 20° at the bottom and 90° at the top, for a difference in elevation of about 500 m. The site has been affected by three rock falls (with a volume of about 30,000 m3) in the last fifteen years. The fallen material has filled two gullies. A debris flow occurred in one of this gully in January 2012 and covered a road on a thickness of 4 m. Seismic prospecting was carried out in this 400 long gully and at the cliff top. The results showed that the rock is strongly fractured and deconsolidated over a thickness of at least 10 m and could be affected by further collapses in the near future. A displacement measurement strategy, based on low-cost remote sensing techniques, has been developed in order to obtain spatially-distributed information on the kinematics of the slope and to better understand the double mechanism (fall-flow). Different remote sensing optical techniques using various platforms (satellite, helicopter, drone, and ground) have been first applied in order to obtain DEMs of the site at various scales. The resolution ranges from 1 cm (close range terrestrial optical photogrammetry) to 2 m (Pleiades images), with 50 cm for the helicopter. The DEMs accuracies were estimated from the results of a differential GPS survey. We discuss the optimum strategy to monitor both the flow and the cliff.

  3. Geodynamic framework of large volcanic fields highlighted by SRTM DEMs: Method evaluation and perspectives exampled on three areas from the Cameroon Volcanic Line

    NASA Astrophysics Data System (ADS)

    Nkono, Collin; Féménias, Olivier; Demaiffe, Daniel

    2009-10-01

    This study is a part of a wider investigation to evaluate how much can be learnt by using low-cost methods such as systematic moderate-resolution remote sensing to map and quantify geological structures at the regional scale on very large volcanic provinces only partly studied in the field. Volcanic-centre and cinder-cone distribution, faults and structural lineaments are mapped combining Shuttle Radar Topography Mission (SRTM), Digital Elevation Models (DEMs) and Landsat satellite images. As an example of the method, we present the interpretation of structural data and morphological features of three contrasted areas from the Cameroon Volcanic Line (Tombel graben, Upper Benue valley, and Ngaoundéré area) for which local field studies are available for comparison. At a local scale, this remote-sensing method of mapping displays good to excellent correlations with previously published data and, by itself, it allows one to constrain the structural setting of each area. Numerical treatment of vent and cinder-cone localisation can be related to tension fractures ( T direction), whereas numerical treatment of the lineaments constrains the associated fault system to a single transtensional (strike-slip + extension) Riedel type fracture network. The first results on the Cameroon Volcanic Line are promising and could be used at a larger scale on numerous volcanic provinces for which field data are not yet available.

  4. Three-dimensional DEM–CFD analysis of air-flow-induced detachment of API particles from carrier particles in dry powder inhalers

    PubMed Central

    Yang, Jiecheng; Wu, Chuan-Yu; Adams, Michael

    2014-01-01

    Air flow and particle–particle/wall impacts are considered as two primary dispersion mechanisms for dry powder inhalers (DPIs). Hence, an understanding of these mechanisms is critical for the development of DPIs. In this study, a coupled DEM–CFD (discrete element method–computational fluid dynamics) is employed to investigate the influence of air flow on the dispersion performance of the carrier-based DPI formulations. A carrier-based agglomerate is initially formed and then dispersed in a uniformed air flow. It is found that air flow can drag API particles away from the carrier and those in the downstream air flow regions are prone to be dispersed. Furthermore, the influence of the air velocity and work of adhesion are also examined. It is shown that the dispersion number (i.e., the number of API particles detached from the carrier) increases with increasing air velocity, and decreases with increasing the work of adhesion, indicating that the DPI performance is controlled by the balance of the removal and adhesive forces. It is also shown that the cumulative Weibull distribution function can be used to describe the DPI performance, which is governed by the ratio of the fluid drag force to the pull-off force.

  5. Scale-dependency of stream gradients derived from LiDAR DEM and its relationship to watershed morphology in the Southern Japanese Alps

    NASA Astrophysics Data System (ADS)

    Hayakawa, Y. S.; Imaizumi, F.; Hattanji, T.

    2008-12-01

    Bedrock erosion in streams is a key element in determining topography of mountain watershed. Failures in steep slopes can often be controlled by riverbed incision with regard to base level changes, where knickzone propagation often has a significant impact on such stream incision. Here we analyze longitudinal morphology of bedrock rivers in a steep mountain watershed in terms of stream gradient, using a high-resolution (1 m) LiDAR DEM in a steep mountain watershed at Ikawa, central Japan. By computing stream gradients with different measure lengths, scale-dependent changes in the gradient are revealed. Relative steepness of riverbed is then quantified using the scaling gradients. Spatial distribution of relative steepness in the watershed indicates that longitudinal riverbed morphology often correspond to morphological condition of slopes with differing types of channel head. Streams in subwatersheds with gentle slopes have less steepness while those in subwatersheds with steep slopes in which failures are frequent. These differences are not likely derived from lithological or tectonic factors, but from geomorphic history in the watershed. The steepness index can also be used for detection of knickzones comprising small knickpoints and waterfalls, whereas location of knickzones has rarely been identified quantitatively in such an uppermost steep mountainous watersheds. The distribution of relative steepness and knickzones possibly reflect incision waves occurring in the watershed: late- or post-glacial base level lowering could have caused formation of knickzones, and some of the propagating knickzones reached upper portions in the watershed while the uppermost area seems to be preserved.

  6. Kanban - der Weg ist das Ziel

    NASA Astrophysics Data System (ADS)

    Aull, Florian; Berlak, Joachim; Dickmann, Eva; Dickmann, Philipp; Fischäder, Holm; Gerlach, Joachim; Henneberg, Jens; Kapalla, Klaus; Kress, Oliver; Kuttler, Robert; Schneider, Herfried M.; Schürle, Philipp; Stellpflug, Franz-Josef; Wannenwetsch, Ralph; Wulz, Johannes; Zäh, Michael F.

    Wenn man aktuell Produktionsbereiche in Deutschland und Europa besucht, fallen im Zusammenhang mit modernen Produktionsmethoden immer öfter die Begriffe Kanban (jap. Karte, Signal) und Pull-Produktion, und dies nicht ohne Stolz, da diese mit dem schillernden Vorbild des Toyota Produktionssystems in Zusammenhang stehen. Tatsächlich ist Kanban ein integraler Bestandteil moderner Produktionssysteme. Blickt man aber im Rahmen von Prozessanalysen hinter die Fassaden", d. h. in die tägliche Praxis der Arbeitsprozesse, wird man schnell desillusioniert - die viel gepriesenen klassischen Kanban-Regeln werden im Tagesgeschäft nicht eingehalten.

  7. Discrimination of fluvial, eolian and neotectonic features in a low hilly landscape: A DEM-based morphotectonic analysis in the Central Pannonian Basin, Hungary

    NASA Astrophysics Data System (ADS)

    Ruszkiczay-Rüdiger, Zsófia; Fodor, László; Horváth, Erzsébet; Telbisz, Tamás

    2009-03-01

    The Gödöll? Hills, a low-relief terrain within the Central Pannonian Basin in Hungary, is characterised by moderate tectonic deformation rates. Although typical tectonic landforms are not clearly recognisable in the study area, this paper succeeded in discriminating between tectonically controlled landforms and features shaped by fluvial erosion or deflation with no tectonic control. DEM-based morphometric parameters including elevation, slope and surface roughness, enabled the delineation of two NW-SE trending spearhead-shaped ridges separated by a wide rectilinear valley of the same strike. Although directional statistics suggested possible tectonic control of NW-SE striking landforms, precise morphometry completed with an analysis of subsurface structures rejected their tectonic preformation. Deflation plays a significant role in shaping the area, and the presence of two large-scale yardangs separated by a wind channel is proposed. In temperate-continental areas of Europe, no deflational landforms of such scale have been described so far, suggesting that Pleistocene wind power in periglacial areas was more significant than it was previously thought. Characteristic drainage patterns and longitudinal valley profiles enabled the recognition of areas probably affected by neotectonic deformation. A good agreement was observed between locations of Quaternary warping predicted by the morphometric study and subsurface structures revealed by the tectonic analysis. Zones of surface uplift and subsidence corresponded to anticlinal and synclinal hinges of fault-related folds. In low-relief and slowly-deforming areas, where exogenous forces may override tectonic deformation, only the integrated application of morphometric and subsurface-structural indications could assure correct interpretation of the origin of various landforms, while a morphometric study alone could have led to misinterpretation of some morphometric indices apparently suggesting tectonic preformation. On the other hand, the described morphological expression of subsurface structures could verify Quaternary age of the deformation.

  8. Nonlinear Force-Free Magnetic Fields of Active Regions based on automated loop tracing in AIA/SDO images with DEM discrimination of chromospheric and coronal features

    NASA Astrophysics Data System (ADS)

    Aschwanden, Markus J.; Boerner, P.; AIA/SDO Team

    2013-07-01

    We developed a forward-fitting code that computes a nonlinear force-free magnetic field (NLFFF) solution constrained by line-of-sight magnetograms from HMI/SDO and by coronal loop structures detected in EUV images from AIA/SDO. The 2D coordinates of coronal loop structures are detected with an improved version of the Oriented Coronal CUrved Loop Tracing (OCCULT-2) code, an automated pattern recognition algorithm that has demonstrated a quality and fidelity in loop tracing that matches visual perception. One fundamental limitation in the completeness of detecting coronal loops comes from the background confusion of coronal loop EUV emission with low-temperature (T=10^4-10^6 K) emission from the chromosphere and transition region, as well as T ~ 1.0 MK emission from reticulated ``moss structure'' that stems from the footpoints of hotter (T 2-8 MK) coronal loops. We employ a pixel-wise differential emission measure (DEM) analysis using the 7 coronal AIA filters in order to produce uncontaminated emission measure maps in coronal temperature ranges, which allows an improved performance of automated loop tracing. A nonlinear force-free magnetic field solution is then computed by forward-fitting of an analytical NLFFF solution of twisted coronal field lines to the automatically traced coronal loop coordinates. We demonstrate the performance of this magnetic field modeling for a number of solar active regions observed with SDO. The developed method is able to calculate the most realistic magnetic field models of solar active regions that match all available observable constraints.

  9. Anti-nuclear liberals and the bomb: A comparative history of Kampf dem Atomtod and the Committee for a Sane Nuclear Policy, 1957-1963

    SciTech Connect

    Thiede, B.

    1992-01-01

    The premises of Kampf dem Atomtod (KdA) and Citizens for a Sane Nuclear Policy (SANE) were based on nineteenth century traditions of liberal peace advocacy. Both groups gained substantial public support for their goals to prevent the nuclear armament of the Bundeswehr and to stop nuclear testing. Both organizations won well-educated middle-class and mostly white supporter. The dissertation examines the role of women: whether housewife or doctor, women stressed their special concerns as mothers. Both KdA and SANE had troubled relations with the labor movement. Their leaders hoped to gain government leaders' respect by winning a respectable, non-Communist constituency and claiming their goals were reasonable ones. Government officials attacked KdA and SANE as dupes of Moscow. Many supporters left the organizations because of their strict anti-Communism. Local groups accused their leaders of lacking initative. KdA and SANE's leaders wasted time and energy rehashing issues and postponing decisions. After a period of providing initiatives and ideas local committees disintegrated. Both organizations considered education their paramount goal but their arguments primarily reached the converted, who often preferred more political action. KdA and SANE's leaders instead chose to support respectable projects based on humanitarian ideals. Since these projects offered little in the way of concrete action agendas, supporters defected to more active organizations or slipped into apathy. Neither organization achieved its national goals. Both governments generally denied them access to the policymaking process, ignored them as irrelavant, or attacked them as Communist sympathizers. While SANE and KdA were heard by those concerned by nuclear policy, and while members of SANE's National Board did help muster support for the Partial Test Ban Treaty, both organizations failed to make liberal peace values productive in the nuclear decisionmaking process.

  10. Contour to DEM Michael Gousie

    E-print Network

    Franklin, W. Randolph

    Data 8 #12;' & $ Interpolation & Approximation In- troduction Desirable properties: local control, and the desired properties mutually contradictory. E.g., Interpolating N-degree polynomial to N-1 points in 2D Contour Lossily Compressed Gridded Approximation Features 3 #12;' & $ So What's New? People have

  11. Das Kreuz auf dem Schlachtfeld 

    E-print Network

    Schmidlin, A. [author

    2012-03-05

    .4.15. [Stamped] 1. Mobl. Landsturm-Inft.-Batl. Heidelberg, 2. Komp. [An] Frä ulein Maria Kolbe, Heidelberg, Kronprinzenstr. 28. Saarburg 11.....4.15. [Stamped] 1st Heidelberg Mobile Home Guard Infantry Battalion, 2nd Company. [To] Ms. Maria Kolbe, Heidelberg, Kronprinzenstr. 28. Saarburg...

  12. DEM EROLU ERDEM Baheehir University

    E-print Network

    Erdem, Cigdem Eroglu

    ) supported by Turkish Scientific and Technical Research Council (TUBITAK), EEAG-110E056, 2010 - 2013. o "3D-PI) supported by Turkish Scientific and Technical Research Council (TUBITAK) ), EEAG-110E053, 2010 - 2013. o-based E-learning system", supported by the Scientific and Technological Research Council of Turkey

  13. Estimating Mangrove Canopy Height and Above-Ground Biomass in Everglades National Park with Airbone LiDAR and TanDEM-X Data.

    NASA Astrophysics Data System (ADS)

    Feliciano, E. A.; Wdowinski, S.; Potts, M. D.; Fatoyinbo, T. E.; Lee, S. K.

    2014-12-01

    The coastal mangroves forests of Everglades National Park (ENP) are well protected from development. Nevertheless, climate change, hurricanes and other anthropogenic disturbances have affected these intertidal ecosystems. Understanding and monitoring forest structural parameters such as canopy height and above-ground biomass (AGB) are important for the establishment of an historical database for past, present and future ecosystem comparison. Forest canopy height has a well understood and directly proportional correlation with AGB. It is possible to derive it using (1) airborne LiDAR/Laser Scanning (ALS) or (2) space-borne radar systems such as Shuttle Radar Topography Mission (SRTM) and TanDEM-X (TDX). A previous study of the mangrove canopy height and AGB in the ENP was conducted a decade ago based on ALS data acquired in 2004 in conjunction with SRTM data, which were acquired in 2000 (Simard et al. 2006). In this study we estimated canopy height and AGB using an ALS dataset acquired in 2012 and TDX data acquired during the years 2012-2014. The ALS dataset was acquired along a 16.5 x 1.5 km swath of mangrove forest with variable canopy height. The sampled areas were representative of mangrove stature and structure in the whole ENP. Analysis of the ALS dataset showed that mangrove canopy height can reach up to ~25 meters close to the coastal ENP waters. Additionally, by comparing our ALS results with those of a previous study by Simard et al. (2006) we identified areas where mangrove height changes greater than ± 3 meters occurred. To expand the study area to the full ENP mangrove ecosystem we processed single-polarization TDX data to obtain a Digital Canopy Model (DCM) that represents the mangrove canopy height. In order to obtain the true canopy height we calibrated the TDX phase center height with ALS true canopy height. Preliminary results of a corrected single-polarized (HH) TDX scene show that mangrove canopy height can reach up to ~25 meters in the western region of the ENP.

  14. Remote-sensing of Riverine Environments Utilized by Spawning Pallid Sturgeon Using a Suite of Hydroacoustic Tools and High-resolution DEMs

    NASA Astrophysics Data System (ADS)

    Elliott, C. M.; Jacobson, R. B.; DeLonay, A. J.; Braaten, P. J.

    2013-12-01

    The pallid sturgeon (Scaphirynchus albus) inhabits sandy-bedded rivers in the Mississippi River basin including the Missouri and Lower Yellowstone Rivers and has experienced decline generally associated with the fragmentation and alteration of these river systems. Knowledge gaps in the life history of the pallid sturgeon include lack of an understanding of conditions needed for successful reproduction and recruitment. We employed hydroacoustic tools to investigate habitats utilized by spawning pallid sturgeon in the Missouri River in Missouri, Kansas, Iowa, and Nebraska, and the Yellowstone River in Montana and North Dakota USA from 2008-2013. Reproductive pallid sturgeon were tracked to suspected spawning locations by field crews using either acoustic or radio telemetry, a custom mobile mapping application, and differential global positioning systems (DGPS). Female pallid sturgeon were recaptured soon after spawning events to validate that eggs had been released. Habitats were mapped at presumed spawning and embryo incubation sites using a multibeam echosounder system (MBES), sidescan sonar, acoustic Doppler current profiler, an acoustic camera and either a real-time kinematic global positioning system (RTK GPS) or DGPS. High-resolution DEM's and velocimetric maps were gridded from at a variety of scales from 0.10 to 5 meters for characterization and visualization at spawning and presumed embryo incubation sites. Pallid sturgeon spawning sites on the Missouri River are deep (6-8 meters) and have high current velocities (>1.5 meters per second). These sites are also characterized by high turbidity and high rates of bedload sediment transport in the form of migrating sand dunes. Spawning on the channelized Lower Missouri River occurs on or adjacent to coarse angular bank revetment or bedrock. Collecting biophysical information in these environmental conditions is challenging, and there is a need to characterize the substrate and substrate condition at a scale relevant to spawning fish and developing embryos (< 1 meter). The Yellowstone River in Montana and North Dakota provides the closest analog to a reference condition for pallid sturgeon spawning habitat with a natural flow regime and relatively natural channel geomorphology. Recent documented suspected spawning on the Yellowstone River occurs in a a sand-bedded reach with patches of gravel deposits, in zones of higher velocity (1.0-1.5 meters per second) compared to the ranges of velocities available in an adjacent reach and over a range of depths (2-5 meters). Results from substrate assessments at pallid sturgeon spawning sites on the Missouri and Yellowstone Rivers may have implications for sediment and flow management as well as provide guidance for potential habitat manipulation in support of the recovery of the pallid sturgeon.

  15. Insights on the 2010 Lava Flows of Piton de la Fournaise Using Cosmo-SkyMed and TanDEM-X Data: Lava Displacement Rates, Thicknesses, and Volume Estimates

    NASA Astrophysics Data System (ADS)

    Bato, M. G.; Froger, J. L.; Harris, A. J. L.; Villeneuve, N.

    2014-12-01

    Characterization of lava flow after its emplacement provides volume and constraints for lava flow emplacement simulations that help assess pending volcanic hazards. Additionally, it gives us better insights in understanding the dynamics of the underlying magmatic plumbing system and the possible mechanism of the eruption. In this work, we developed a technique using monostatic Cosmo-SkyMed and bistatic TanDEM-X data to calculate the volume, measure the thickness, and the horizontal and vertical displacements immediately after the emplacement of the October 2010 lava flow at Piton de la Fournaise. Results show that the thickest part of the October 2010 lava flow is about 13 to 16 m and the DRE volume is estimated to fall within the range of 1.71 to 3.00 x 106 m3 (±1?), depending on which InSAR database was used. We also observe that the October 2010 lava flow is subsiding at a maximum rate of 14 cm yr-1. Apart from the vertical displacement, joint sliding and centripetal displacement were also identified with a maximum rate of 4.0 cm yr-1. We cross-validated our InSAR results with the mixed-pixel technique of Harris [1997] in terms of the estimated volumes. Our analysis shows that the volume derived using a few TanDEM-X interferograms fitted well within the range of volume given by the mixed-pixel technique as compared to the huge monostatic Cosmo-SkyMed database. In addition to the October 2010 lava flow, we also characterized the thin lava flow deposit of the December 2010 eruption, however using only bistatic TanDEM-X data. In this case of thin lava deposits, we expect that TanDEM-X are best to use in deriving the thickness and estimating the volume as these type of data are more sensitive to topographic change. Reference: Harris AJL, Blake S, Rothery DA, Stevens NF., 1997. A chronology of the 1991 to 1993 Mount Etna eruption using advanced very high resolution radiometer data: implications for real-time thermal volcano monitoring. Geophys. Res. Lett. 102:7985-8003.

  16. Pit Craters and Collapse Calderas: Structural Influences of Initial Mechanical and Geometric Properties as revealed by 2D Distinct Element Method (DEM) Models

    NASA Astrophysics Data System (ADS)

    Holohan, E. P.; Schöpfer, M. P.; Walsh, J. J.

    2009-12-01

    Pit craters and collapse calderas are volcanic depressions produced by subsidence of the roof of a magma reservoir. They are near-ubiquitous features of volcanic fields or edifices on Earth and other terrestrial planets. Pit crater and caldera subsidence may occur by diverse structural mechanisms, each previously linked with various initial controlling factors. We present Distinct Element Method (DEM) numerical models of this subsidence process to shed new light on such mechanisms and the factors controlling them. Our models comprise an assemblage of gravitationally-loaded circular particles that interact at their contacts according to elastic-frictional laws. Cohesion is provided by inter-particle bonds that break once their shear or tensile strength is exceeded. Varying particle and bond micro-properties yielded assemblage macro-properties and rheological responses characteristic of natural rock masses (e.g. elasticity, failure, and strain softening), with fracture localization simulated by bond breakage. The magma reservoir is represented as a region of non-bonded, low-friction particles. Withdrawal of magma is simulated by incrementally reducing the area of the reservoir particles. The resultant gravity-driven failure and subsidence of the overlying reservoir roof is explicitly replicated. We have investigated the effect on subsidence of initial mechanical and geometric properties. The former included Young’s Modulus and strength (cohesion), whilst the latter included the thickness/diameter ratio (T/D) of the roof and the ceiling curvature imparted by the shape of the underlying reservoir. These initial mechanical and geometric properties interacted to produce several ‘end-member’ subsidence mechanisms: (1) Predominantly central sagging at low strength and low T/D; (2) predominantly single central block subsidence at low to intermediate strength and at intermediate T/D; (3) multiple central block subsidence at high strength and high T/D; (4) a hitherto unrecognized ‘central snapping’ mechanism at high strength, low T/D, and with a low ceiling curvature. In terms of material properties, the occurrence of these mechanisms was weakly dependent on Young’s Modulus, but strongly dependent on material strength. In terms of geometric properties, a moderate dependency on reservoir shape at low T/D diminished at intermediate and high T/D. One important outcome of the interaction of mechanical and geometric properties is that the critical T/D ratio, above which the single central block mechanism changes to the multiple central block mechanism, decreases from > 1 to < 0.6 with increasing material strength. Our model results agree well with those of analogue studies of pit crater and caldera subsidence, and provide a more quantitative understanding of the genesis of different mechanisms observed in the field - e.g. at Nindiri crater, Nicaragua and Miyakejima caldera, Japan.

  17. Black Hawk Down: Film Zwischen Reflektion und Konstruktion Gesellschaftlicher Wirklichkeit

    NASA Astrophysics Data System (ADS)

    Pötzsch, Holger

    2009-05-01

    BLACK HAWK DOWN: FILM BETWEEN THE REFLECTION AND CONSTRUCTION OF SOCIAL REALITY - In this article, Ridley Scott's film Black Hawk Down (USA 2001) is read in the context of contemporary theories concerning cultural memory (Jan and Aleida Assmann) and media culture (Douglas Kellner). It is argued that film (and representation in general) does not merely reflect a preceding reality; it also actively serves to construct it. It is shown how Scott's film privileges one particular perspective on an actual event and how this point of view is objectified and installed in the memory of Western media culture. What potential implications does an increased blurring of fact and fiction in the representation of war have? What are the consequences for political and pedagogical practice? What role can cultural studies play in these processes?

  18. An algorithm for generalizing topography to grids while preserving subscale morphologic characteristics—creating a glacier bed DEM for Jakobshavn trough as low-resolution input for dynamic ice-sheet models

    NASA Astrophysics Data System (ADS)

    Herzfeld, Ute C.; Wallin, Bruce F.; Leuschen, Carlton J.; Plummer, Joel

    2011-11-01

    The objective of this paper is to derive an algorithm for preserving important subscale morphologic characteristics at grids of lower-resolution, in particular for linear features such as canyons and ridge lines. The development of such an algorithm is necessitated by applications that require reduced spatial resolution, as is common in cartographic generalization, GIS applications, and geophysical modeling. Since any algorithm that results in weighted averages, including optimum interpolation and ordinary kriging, cannot reproduce correct depths, a new algorithm is designed based on principles of mathematical morphology. The algorithm described here is applied to derive a subglacial bed of the Greenland Ice Sheet that includes the trough of Jakobshavn Isbræ as a continuous canyon at correct depth in a low-resolution (5-km) digital elevation model (DEM). Data from recent airborne radar measurements of the elevation of the subglacial bed as part of the CReSIS project are utilized. The morphologic algorithm is designed with geophysical ice-sheet modeling in mind, in the following context. Currently occurring changes in the Earth's climate and the cryosphere cause changes in sea level, and the societal relevance of these natural processes motivates estimation of maximal sea-level rise in the medium-term future. The fast-moving outlet glaciers are more sensitive to climatic change than other parts of the Greenland ice sheet. Jakobshavn Isbrae, the fastest-moving ice stream in Greenland, follows a subglacial geologic trough. Since the existence of the trough causes the acceleration of the slow-moving inland ice in the Jakobshavn region and the formation of the ice stream, correct representation of the trough in a DEM is essential to model changes in the dynamics of the ice sheet and resultant sea-level predictions, even if current ice-sheet models can typically be run only at 5-km resolution. The DEM resultant from this study helps to bridge the conceptual gap between data analysis and geophysical modeling approaches. It is available as SeaRISE Greenland bed data set dev1.2 at http://websrv.cs.umt.edu/isis/index.php/SeaRISE_Assessment.

  19. Aerial imagery and structure-from-motion based DEM reconstruction of region-sized areas (Sierra Arana, Spain and Namur Province, Belgium) using an high-altitude drifting balloon platform.

    NASA Astrophysics Data System (ADS)

    Burlet, Christian; María Mateos, Rosa; Azañón, Jose Miguel; Perez, José Vicente; Vanbrabant, Yves

    2015-04-01

    A new type of untethered balloon based mapping platform allows affordable remote sensing applications from higher altitudes and with a greater range and payload capacity than common motorized UAV's. The airborne device, called "Stratochip", is based on a dual helium balloons configuration. At a defined altitude (comprised between 1000 and 30000m), the first balloon is released, drastically reducing the platform climbing rate. The payload (up to 10kg) can then drift in a sub-horizontal trajectory until it leaves a pre-defined area of interest. Leaving the pre-defined area, the second balloon is released and the payload is recovered after a parachute landing. The predicted flight path of the Stratochip, launch site and surveyed area are calculated using both forecasted (NOAA model) and real-time (inborne instruments) meteorological data, along with the physical parameters of the balloons and parachute. The predicted recovery area can also be refined in real-time to secure and facilitate equipment retrieval. In this study, we present the results of two cartographic campaigns made in Belgium (Famennian outcrops near Beauraing, Namur Province) and Spain (karstic field in the Eastern part of Sierra Arana, Granada region). Those campaigns aimed to test the usability of the Stratochip to survey a large area at medium altitudes (3000m-8000m) and produced an updated Digital Elevation Model and orthophoto mosaic of those regions. For that purpose, the instrument installed in the Stratochip payload was constituted of a digital camera stabilized with two IMU's and two brushless motors. An automated routine then tilted the camera at predefined angles while taking pictures of the ground. This technique allowed to maximize the photogrammetric information collected on a single pass flight, and improved the DEM reconstruction quality, using structure-from-motion algorithms. Three sets of data (DEM + orthophoto) were created from those campaigns, using pictures sets collected a different elevations. A 1m/pixel ground resolution set covering an area of about 200km² and mapping the eastern part of the Sierra Arana (Andalucía, Spain) includes a kartsic field directly to the south-east of the ridge and the cliffs of the "Riscos del Moro". A 4m/pixel ground resolution set covering an area of about 900km² includes the landslide active Diezma region (Andalucía, Spain) and the water reserve of Francisco Abellan lake. The third set has a 3m/pixel ground resolution, covers about 100km² and maps the Famennian rocks formations, known as part of "La Calestienne", outcropping near Beauraing and Rochefort in the Namur Province (Belgium). The DEM and orthophoto's have been referenced using ground control points from satellite imagery (Spain, Belgium) and DPGS (Belgium). The quality of produced DEM were then evaluated by comparing the level and accuracy of details and surface artefacts between available topographic data (SRTM- 30m/pixel, topographic maps) and the three Stratochip sets. This evaluation showed that the models were in good correlation with existing data, and can be readily be used in geomorphology, structural and natural hazard studies.

  20. An Automated System of Knickpoint Definition and Extraction from a Digital Elevation Model (DEM): Implications for Efficient Large-Scale Mapping and Statistical Analyses of Knickpoint Distributions in Fluvial Networks

    NASA Astrophysics Data System (ADS)

    Neely, A. B.; Bookhagen, B.; Burbank, D. W.

    2014-12-01

    Knickpoints, or convexities in a stream's longitudinal profile, often delineate boundaries in stream networks that separate reaches eroding at different rates resulting from sharp temporal or spatial changes in uplift rate, contributing drainage area, precipitation, or bedrock lithology. We explicitly defined the geometry of a knickpoint in a manner that can be identified using an algorithm which operates in accordance with the stream power incision model, using a chi-plot analysis approach. This method allows for comparison between the real stream profile extracted from a DEM, and a linear best-fit line profile in chi-elevation space, representing a steady state theoretical stream functioning in accordance to uniform temporal and spatial conditions listed above. Assessing where the stream of interest is "under-steepened" and "over-steepened" with respect to a theoretical linear profile reveals knickpoints as certain points of slope inflection, extractable by our algorithm. We tested our algorithm on a 1m resolution LiDAR DEM of Santa Cruz Island (SCI), a tectonically active island 25km south of Santa Barbara, CA with an estimated uplift rate between 0.5 and 1.2mm/yr calculated from uplifted paleoshorelines. We have identified 1025 knickpoints using our algorithm and compared the position of these knickpoints to a similarly-sized dataset of knickpoints manually selected from distance-elevation longitudinal stream profiles for the same region. Our algorithm reduced mapping time by 99.3% and agreed with knickpoint positions from the manually selected knickpoint map for 85% of the 1025 knickpoints. Discrepancies can arise from inconsistencies in manual knickpoint selection that are not present in an automated computation. Additionally, the algorithm measures useful characteristics for each knickpoint allowing for quick statistical analyses. Histograms of knickpoint elevation and chi coordinate have a 3 peaked distribution, possibly expressing 3 levels of uplifted marine terrace platforms on SCI. Few knickpoints exist with a contributing drainage area >200,000m2, demonstrating a cutoff drainage area where knickpoint migration has stalled. We intend to use this tool to further explore the significance, evolution, and dynamics of knickpoint features on SCI.

  1. MITTEILUNGSBLATT DES REKTORS

    E-print Network

    Heermann, Dieter W.

    Aufbaumodule, wird das Modul ,,Base Studies in Computational Linguistics" wie folgt neu gefasst: Base Studies in Computational Linguistics Relevanz für Studienfachnote: ja Modul und zugehörige Lehrveranstaltungen Modulart in Computational Linguistics" besteht die Wahl zwischen einer Veranstaltung entweder aus dem Bereich der

  2. Geodtisch-geophysikalische Arbeiten in der Schweiz

    E-print Network

    Giger, Christine

    -Arbeit zwischen dem Autor und seinem ehemaligen Fachkollegen Stéphane Guerrier (zur Zeit Doktorand an der ist jedoch sehr aufwendig und ist das Verdienst des Autors. Konkret hat er die Leistung der technique subit actuellement une petite révolution grâce à l'arrivée de systèmes micro

  3. Entwicklung eines hocheffizienten Photovoltaikwechselrichters fr den Leistungsbereich von 100 bis 500 kW

    E-print Network

    Noé, Reinhold

    freie Wahl zwischen IGBTs und MOSFETs besteht, da es möglich ist, die Endstufe diskret aufzubauen und Wechselrichtertopologien realisieren. Durch geschickte Nutzung der Vorteile von IGBTs (niedrige Durchlassver- luste) und Sili- ziumkarbid (SiC) Dioden und JFETs bzw. MOSFETs [1], [2] mit dem großen Vorteil der Reduzierung

  4. Auf dem Weg zum universellen Quantencomputer

    NASA Astrophysics Data System (ADS)

    Jaksch, Dieter; Calarco, Tommaso; Zoller, Peter

    2000-11-01

    Die Quantenmechanik eröffnet faszinierende Perspektiven für die Kommunikation und die Informationsverarbeitung. Um universell programmierbare Quantenrechner realisieren zu können bedarf es der Implementierung von Konzepten zur Quanteninformationsverarbeitung die sich auf eine große Anzahl von Qubits anwenden lassen.

  5. Dem Generation with WORLDVIEW-2 Images

    NASA Astrophysics Data System (ADS)

    Büyüksalih, G.; Baz, I.; Alkan, M.; Jacobsen, K.

    2012-07-01

    For planning purposes 42 km coast line of the Black Sea, starting at the Bosporus going in West direction, with a width of approximately 5 km, was imaged by WorldView-2. Three stereo scenes have been oriented at first by 3D-affine transformation and later by bias corrected RPC solution. The result is nearly the same, but it is limited by identification of the control points in the images. Nevertheless after blunder elimination by data snooping root mean square discrepancies below 1 pixel have been reached. The root mean square discrepancy at control point height reached 0.5 m up to 1.3 m with a base to height relation between 1:1.26 and 1:1.80. Digital Surface models (DSM) with 4 m spacing have been generated by least squares matching with region growing, supported by image pyramids. A higher percentage of the mountainous area is covered by forest, requiring the approximation based on image pyramids. In the forest area the approximation just by region growing leads to larger gaps in the DSM. Caused by the good image quality of WorldView-2 the correlation coefficients reached by least squares matching are high and even in most forest areas a satisfying density of accepted points was reached. Two stereo models have an overlapping area of 1.6 km times 6.7 km allowing an accuracy evaluation. Small, but nevertheless significant differences in scene orientation have been eliminated by least squares shift of both overlapping height models to each other. The root mean square differences of both independent DSM are 1.06m or as a function of terrain inclination 0.74 m + 0.55 m ? tangent (slope). The terrain inclination in the average is 7° with 12% exceeding 17°. The frequency distribution of height discrepancies is not far away from normal distribution, but as usual, larger discrepancies are more often available as corresponding to normal distribution. This also can be seen by the normalized medium absolute deviation (NMAS) related to 68% probability level of 0.83m being significant smaller as the root mean square differences. Nevertheless the results indicate a standard deviation of the single height models of 0.75 m or 0.52 m + 0.39* tangent (slope), corresponding to approximately 0.6 pixels for the x-parallax in flat terrain, being very satisfying for the available land cover. An interpolation over 10 m enlarged the root mean square differences of both height models nearly by 50%.

  6. Diesel Exhaust in Miners Study (DEMS)

    Cancer.gov

    In March 2012, the National Cancer Institute (NCI) and the National Institute for Occupational Safety and Health (NIOSH) completed a retrospective cohort mortality and nested case-control study of 12,315 workers at eight non-metal mining facilities to investigate risk of lung cancer in relation to quantitative measures of historical exposure to diesel exhaust, after taking into account smoking and other lung cancer risk factors

  7. Objective constitutive relations from DEM Stefan Luding

    E-print Network

    Luding, Stefan

    by an error-function #12;2 (Fenistein, van de Meent, and van Hecke 2004; Luding 2004b; Luding 2006b of the ring-shaped geometry is simulated. The walls are cylindrical, and are roughened due to some (about 3

  8. Mit dem Zufall rechnen -oder lieber ohne?

    E-print Network

    Jüttler, Bert

    Johannes Kepler Universität Linz 19. Januar 2015 #12;Computing with randomness - or better without? Inaugural Lecture Aicke Hinrichs Institute of Analysis Johannes Kepler University Linz January 19, 2015 #12

  9. Dem Bones: Forensic Resurrection of a Skeleton.

    ERIC Educational Resources Information Center

    Bruce, Alease

    2001-01-01

    Presents an activity for students to determine the sex and age of an individual from a collection of bones. Simulates some of the actual procedures conducted in a forensic anthropologist's lab, examining and identifying bones through a series of lab activities. (Author/ASK)

  10. Future earthquake source faults on deep sea-floor around the Boso triple plate junction revealed by tectonic geomorphology using 3D images produced from 150 meter grid DEM

    NASA Astrophysics Data System (ADS)

    Goto, H.; Nakata, T.; Watanabe, M.; Suzuki, Y.; Izumi, N.; Nishizawa, A.; Horiuchi, D.; Kido, Y. N.

    2013-12-01

    Boso triple junction, which is the only example of a triple trench junction on earth, is located off the southeast of Boso peninsula, where the Izu-Bonin trench meets with the Japan trench and the Sagami trench. Boso submarine canyon, which is extended to Katsuuma basin about 7000m deep, forms an incised meander along the north side of Sagami trough. Taito spur separate Katsuuma basin from Bando abyssal basin about 9000m deep, where Japan trench meet with Isu-Bonin trench. In this paper, we present detailed stereo-paired topographic images produced from 0.002 degree (about 150m) DBEM (Digital Bathymetry Model), which processed from the depth sounding data obtained by Japan Coast Guard and JAMSTEC around Boso triple junction. It enables us to observe submarine geomorphology easily and precisely. We identified submarine active faults and other tectonic features related to subduction by using the similar standard for air-photo interpretation of inland active faults. We made more precise submarine active tectonic geomorphological map around Boso triple junction than that by previous workers. Numerous distinct faults on the so-called outer rise associated with subduction of Pacific plate are regarded as normal faulting as widely accepted. While the normal faults on the outer rise are parallel to the trench in the southern part of the Japan trench and the northern part of the Izu-Bonin trench, these normal faults around the east of the triple junction with NNW-SSE extend slightly oblique to the trench. The western margin of Bando abyssal basin is bounded by the thrust faults, which form east-facing 200-500m-high convex scarps associated with raised basin floor to the west of the scarp. These faults also deform Mogi submarine fan surface and uplift to the west along the extension of the scarp. The antecedent valley is extended for about 10km across Taito spur that is an active anticlinal ridge about 1000m high. Katsuura basin is surrounded by terraced former basin floor that is tilted to the west, indicating up-growing of Taito spur. Northeastern part of Izu bar on Philippine Sea plate is characterized by rather smooth extensive convex slope between 1500m-7500m for over 200km long along the trench. On the lower part of the slope below 6000m, several gullies such as Mikura canyon and Kita-Hachijo canyon dissecting the slope forms rapids, probably due to continuous up-warping by subsurface thrusting dipping to the west under the slope. It is noteworthy that we can identify prominent active tectonic features on even very deep sea-floor along the plate boundaries, by using 3D images produced from 150 meter grid DEM.

  11. Das Social Semantic Web aus kommunikationssoziologischer Perspektive

    NASA Astrophysics Data System (ADS)

    Schmidt, Jan; Pellegrini, Tassilo

    Zwei Trends prägen derzeit die Gestalt des Internets: Auf der einen Seite finden sich Entwicklungen rund um das Web 2.0" oder Social Web", die dem einzelnen Nutzer neue Möglichkeiten des onlinegestützten Identitäts-, Beziehungs- und Informationsmanagements eröffnen. Auf der anderen Seite stehen die Innovationen des Semantic Web, die Relationen zwischen Datenbeständen strukturieren helfen, um so zu verbesserten maschinellen Repräsentationen von Wissen zu gelangen. Dieser Beitrag skizziert die Idee eines Social Semantic Web", in dem beide Entwicklungen zusammenfließen. Als Scharnier dient dabei der Begriff der Prodnutzung, der die aktive Rolle des Nutzers bei der Erstellung, Verbreitung und Weiterentwicklung von Inhalten wie von strukturiertem Wissen betont.

  12. Herausforderungen und Best Practices bei der Speicherung von multi-valued Attributen in LDAP-basierten Verzeichnisdiensten

    NASA Astrophysics Data System (ADS)

    Hommel, Wolfgang; Pluta, Daniel

    LDAP-basierte Verzeichnisdienste unterscheiden sich von relationalen Datenbankmanagementsystemen unter anderem stark bezüglich der Datenmodellierung. Dieser Artikel vertieft eingangs die Herausforderungen bei der LDAP-spezifischen Abbildung von Relationen zwischen mehreren multivalued Attributen. Die Diskussion erfolgt vor dem Hintergrund, dass einerseits Verzeichnisdienste generell nur bedingt zur Speicherung von Relationen geeignet sind und dass andererseits multi-valued Attribute ein mächtiges LDAP-Instrument sind, zu dem es in relationalen Datenbanksystemen keine direkte Entsprechung gibt. Anschließend werden Lösungskonzepte vorgestellt und mögliche Weiterentwicklungen des IntegraTUM-LDAP-Schemas zu deren Umsetzung skizziert, eine exemplarische Implementierung präsentiert und die Ergebnisse der bisherigen Entwicklung des IntegraTUM-Schemas gegenübergestellt.

  13. „Überholen ohne einzuholen“ Die Entwicklung von Technologien für übermorgen in Kernenergie und Mikroelektronik der DDR

    NASA Astrophysics Data System (ADS)

    Barkleit, Gerhard

    Dem nuklearen Patt zwischen Ostblock und westlichem Staatenbündnis ist es nach weitgehend übereinstimmender Auffassung von Politik und Wissenschaft zu danken, dass der "Kalte Krieg" in der zweiten Hälfte des 20. Jahrhunderts nicht zum weltumfassenden Flächenbrand eskalierte. An der raschen Herstellung dieses Patts waren zwei Dresdner Physiker maßgeblich beteiligt, deren einer im Manhattan-Projekt in den USA gearbeitet hatte und später in England der Spionage für die Sowjetunion und des Verrats des Know-how der Atombombe überführt wurde.

  14. Aufbau von organisationsübergreifenden Fehlermanagementprozessen im Projekt IntegraTUM

    NASA Astrophysics Data System (ADS)

    Hommel, Wolfgang; Knittl, Silvia

    Das Projekt IntegraTUM wird in enger Kooperation zwischen der Technischen Universität München (TUM) und dem Leibniz-Rechenzentrum (LRZ) durchgeführt. In diesem Projekt werden Dienste gemeinsam entwickelt, die nachhaltig vom LRZ betrieben werden sollen. Die damit verbundene Rezentralisierung erfordert auch eine enge Kooperation im Falle von technischen Störungen und Fehlern im Betriebsablauf bei diesen Diensten über die Organisationsgrenzen hinweg. Unsere Aktivitäten in diesem organisationsübergreifenden Fehlermanagement werden hier beschrieben.

  15. VDI-Berichte Nr. 1886, 2005 79 Biosystemtechnologie: Interaktion zwischen biologischen

    E-print Network

    Behnke, Sven

    - Tech Systems (BTS) covers `Smart Drug Delivery Systems' as pharmaceutical products, `Learning Neural Prostheses' as medical devices, Smart Communicators' as communication electronic products, and `Smart Poison

  16. Zwischen Commonsense und Wissenschaft Mathematik in der Erziehungsphilosophie A. N. Whiteheads

    NASA Astrophysics Data System (ADS)

    Sölch, Dennis

    Obwohl Whitehead heute wie selbstverständlich als Philosoph rezipiert wird, so hat er seine wissenschaftliche Laufbahn doch als Mathematiker begonnen. Lange Zeit war er gemeinsam mit Bertrand Russell als Autor der Principia Mathematica unter Mathematikern und mathematischen Logikern deutlich besser bekannt als unter Philosophen. Doch selbst von denjenigen, die sich mit Whiteheads Überlegungen zur Metaphysik, zur Wissenschaftsgeschichte und zur Theologie befassen, werden seine Schriften zur Philosophie von Erziehung und Bildung häufig kaum beachtet. So entgeht es leicht, dass Whitehead nicht nur ein auf theoretischem Gebiet brillanter Mathematiker war, sondern sein theoretisches Fachwissen im Hinblick auf pädagogische und didaktische Relevanz fortwährend reflektiert hat.

  17. Einstellung und Wissen von Lehramtsstudierenden zur Evolution - ein Vergleich zwischen Deutschland und der Türkei

    NASA Astrophysics Data System (ADS)

    Graf, Dittmar; Soran, Haluk

    Es wird eine Untersuchung vorgestellt, in der Wissen und Überzeugungen von Lehramtsstudierenden aller Fächer zum Thema Evolution an zwei Universitäten in Deutschland und der Türkei erhoben worden sind. Die Befragung wurde in Dortmund und in Ankara durchgeführt. Es stellte sich heraus, dass ausgeprägte Defizite im Verständnis der Evolutionsmechanismen herrschen. Viele Studierende, insbesondere aus der Türkei, sind nicht von der Faktizität der Evolution überzeugt. Dies gilt sowohl für Studierende mit Fach Biologie als auch für Studierende mit anderen Fächern. Näher untersucht worden sind die Faktoren, die die Überzeugungen zur Evolution beeinflussen können, was ja in Anbetracht der hohen Ablehnungsrate der Evolution von besonderem Interesse ist. Das Vertrauen in die Wissenschaft spielt hierbei eine besondere Rolle: Wer der Wissenschaft vertraut, ist auch eher von der Evolution überzeugt, als diejenigen, die skeptisch gegenüber der Wissenschaft sind.

  18. Das Gymnasium Zwischen Tradition und Modernen Bildungsanspruchen (The Gymnasium between Tradition and Modern Educational Requirements).

    ERIC Educational Resources Information Center

    Heller, Kurt A.

    2003-01-01

    Provides brief history of the German Gymnasium as a traditional European secondary school system with a preparatory function for higher education. Reviews the main goals of the gymnasium. Asks what role the gymnasium plays as a learning environment for gifted students. Discusses the politico-educational consequences and demands on the gymnasium.…

  19. SEMINAR IM SOMMERSEMESTER 2013 MIT DEM TITEL MENGENLEHRE: KARDINALZAHLINVARIANTEN"

    E-print Network

    Mildenberger, Heike

    . A K Peters, 1995. [3] Murray Bell. On the combinatorial principle P(c). Fund. Math., 114:149­157, 1981. [4] Murray Bell and Kenneth Kunen. On the -character of ultrafilters. C. R. Math. Rep. Acad. Sci-Tukey-Verbindungen, Dualit¨at Aline Wunsch 4. Vortrag (15.5.2013) Date: 5.2.2012. 1 #12;2 HEIKE MILDENBERGER "Category

  20. SEMINAR IM SOMMERSEMESTER 2013 MIT DEM TITEL MENGENLEHRE: KARDINALZAHLINVARIANTEN"

    E-print Network

    Mildenberger, Heike

    . A K Peters, 1995. [3] Murray Bell. On the combinatorial principle P(c). Fund. Math., 114:149­157, 1981. [4] Murray Bell and Kenneth Kunen. On the -character of ultrafilters. C. R. Math. Rep. Acad. Sci-Tukey-Verbindungen, Dualit¨at Aline Wunsch 4. Vortrag (15.5.2013) Date: 18.6.2012. 1 #12;2 HEIKE MILDENBERGER "Category

  1. Coronal response to an EUV wave from DEM analysis

    E-print Network

    Vanninathan, K; Dissauer, K; Madjarska, M S; Hannah, I G; Kontar, E P

    2015-01-01

    EUV (Extreme-Ultraviolet) waves are globally propagating disturbances that have been observed since the era of the SoHO/EIT instrument. Although the kinematics of the wave front and secondary wave components have been widely studied, there is not much known about the generation and plasma properties of the wave. In this paper we discuss the effect of an EUV wave on the local plasma as it passes through the corona. We studied the EUV wave, generated during the 2011 February 15 X-class flare/CME event, using Differential Emission Measure diagnostics. We analyzed regions on the path of the EUV wave and investigated the local density and temperature changes. From our study we have quantitatively confirmed previous results that during wave passage the plasma visible in the Atmospheric Imaging Assembly (AIA) 171A channel is getting heated to higher temperatures corresponding to AIA 193A and 211A channels. We have calculated an increase of 6 - 9% in density and 5 - 6% in temperature during the passage of the EUV wav...

  2. Zur Theorie der Manganate Auf dem Weg zu neuer Elektronik

    E-print Network

    Röder, Beate

    .07.06 1 / 19 #12;Ausblick 1 Einleitung Magnetismus Spintronics Manganate 2 Theoretische Bearbeitung Modell Manganate Lise-Meitner-Feier 20.07.06 2 / 19 #12;Ausblick 1 Einleitung Magnetismus Spintronics Manganate 2 Magnetismus Spintronics Manganate 2 Theoretische Bearbeitung Modell L¨osung des Modells Ergebnisse und

  3. Quarks & Gluonen im Superrechner: Quantenchromodynamik auf dem Gitter

    NASA Astrophysics Data System (ADS)

    Gattringer, Christof

    2004-09-01

    Die Quantenchromodynamik (QCD) ist die heute gültige Quantenfeldtheorie der starken Wechselwirkung. Sie beschreibt die Dynamik des Zusammenspiels von Quarks und Gluonen. Weil die Gluonen mit sich selbst wechselwirken können, ist der traditionelle Zugang über eine Störungsentwicklung nur bei sehr hohen Energien anwendbar. Die elegante Übertragung auf ein vierdimensionales Raumzeit-Gitter macht die QCD der numerischen Berechnung auf Supercomputern zugänglich. Damit können zentrale Probleme wie etwa Hadronmassen oder Matrixelemente bestimmt werden. Heute ist die Gitter-QCD so weit entwickelt, dass sie ein tieferes Verständnis von der Natur der starken Wechselwirkung ermöglicht.

  4. Granular physics in low-gravity environments using DEM

    E-print Network

    G. Tancredi; A. Maciel; L. Heredia; P. Richeri; S. Nesmachnow

    2011-11-26

    Granular materials of different sizes are present on the surface of several atmosphere-less Solar System bodies. The phenomena related to granular materials have been studied in the framework of the discipline called Granular Physics; that has been studied experimentally in the laboratory and, in the last decades, by performing numerical simulations. The Discrete Element Method simulates the mechanical behavior of a media formed by a set of particles which interact through their contact points. The difficulty in reproducing vacuum and low-gravity environments makes numerical simulations the most promising technique in the study of granular media under these conditions. In this work, relevant processes in minor bodies of the Solar System are studied using the Discrete Element Method. Results of simulations of size segregation in low-gravity environments in the cases of the asteroids Eros and Itokawa are presented. The segregation of particles with different densities was analysed, in particular, the case of comet P/Hartley 2. The surface shaking in these different gravity environments could produce the ejection of particles from the surface at very low relative velocities. The shaking causing the above processes is due to: impacts, explosions like the release of energy by the liberation of internal stresses or the re accommodation of material. Simulations of the passage of impact-induced seismic waves through a granular medium were also performed. We present several applications of the Discrete Element Methods for the study of the physical evolution of agglomerates of rocks under low-gravity environments.

  5. Dem Generation with Short Base Length Pleiades Triplet

    NASA Astrophysics Data System (ADS)

    Jacobsen, K.; Topan, H.

    2015-03-01

    An image triplet of Pleiades images covering the area of Zonguldak, Turkey has been investigated. The height to base relation of the first to the last image is just 1:4.5 and for the first and the second image 1:9. This is quite below the usual height to base relation of 1:1.6 for a typical stereo pair of space images. The corresponding small angle of convergence influences the possible vertical accuracy, but images with such a small angle of convergence are more similar to each other as images with larger convergence angles. This enables a better image matching, improving the vertical accuracy and compensating partially the influence of poor intersection geometry. Even over forest areas no matching gaps occurred. Height models are generated with different base configurations and compared with a reference height model. Pleiades images are distributed with 50cm ground sampling distance instead of the physical size of 70cm, the image quality justifies this zooming and also the geometric results are in the range of other space images with originally 50cm GSD. The image orientation by bias corrected Rational Polynomial Coefficients (RPC) is leading with more as 160 ground control points (GCP) to root mean square (RMS) differences slightly below 1.0 GSD of the distributed images (0.5m GSD). Only negligible systematic errors have been identified. With the combination of the first and last image a standard deviation of the generated height model of 1.6m, respectively for flat terrain close to 1.0m has been reached in relation to a reference height model. The small angle of convergence is not as much influencing the height accuracy as according to simple geometric relation.

  6. Nr. 120 // 2015 // 7. Juli 2015 Schampus auf dem Campus!

    E-print Network

    Ott, Albrecht

    Faszination für und durch Wissenschaft, Forschung, Sport und Kunst widmet, einer rauschenden Ballnacht und Jubiläumswochenende am Sonntag beim großen Bigband Event am Audimax-See ausklingen. Let´s swing and groove Danner Leiterin der Stabsabteilung Presse, Marketing und Kommunikation Universität Bayreuth

  7. Forecasting of Storm Surge Floods Using ADCIRC and Optimized DEMs

    NASA Technical Reports Server (NTRS)

    Valenti, Elizabeth; Fitzpatrick, Patrick

    2005-01-01

    Increasing the accuracy of storm surge flood forecasts is essential for improving preparedness for hurricanes and other severe storms and, in particular, for optimizing evacuation scenarios. An interactive database, developed by WorldWinds, Inc., contains atlases of storm surge flood levels for the Louisiana/Mississippi gulf coast region. These atlases were developed to improve forecasting of flooding along the coastline and estuaries and in adjacent inland areas. Storm surge heights depend on a complex interaction of several factors, including: storm size, central minimum pressure, forward speed of motion, bottom topography near the point of landfall, astronomical tides, and most importantly, maximum wind speed. The information in the atlases was generated in over 100 computational simulations, partly by use of a parallel-processing version of the ADvanced CIRCulation (ADCIRC) model. ADCIRC is a nonlinear computational model of hydrodynamics, developed by the U.S. Army Corps of Engineers and the US Navy, as a family of two- and three-dimensional finite element based codes. It affords a capability for simulating tidal circulation and storm surge propagation over very large computational domains, while simultaneously providing high-resolution output in areas of complex shoreline and bathymetry. The ADCIRC finite-element grid for this project covered the Gulf of Mexico and contiguous basins, extending into the deep Atlantic Ocean with progressively higher resolution approaching the study area. The advantage of using ADCIRC over other storm surge models, such as SLOSH, is that input conditions can include all or part of wind stress, tides, wave stress, and river discharge, which serve to make the model output more accurate.

  8. Visualization of small scale structures on high resolution DEMs

    NASA Astrophysics Data System (ADS)

    Kokalj, Žiga; Zakšek, Klemen; Pehani, Peter; ?otar, Klemen; Oštir, Krištof

    2015-04-01

    Knowledge on the terrain morphology is very important for observation of numerous processes and events and digital elevation models are therefore one of the most important datasets in geographic analyses. Furthermore, recognition of natural and anthropogenic microrelief structures, which can be observed on detailed terrain models derived from aerial laser scanning (lidar) or structure-from-motion photogrammetry, is of paramount importance in many applications. In this paper we thus examine and evaluate methods of raster lidar data visualization for the determination (recognition) of microrelief features and present a series of strategies to assist selecting the preferred visualization of choice for structures of various shapes and sizes, set in varied landscapes. Often the answer is not definite and more frequently a combination of techniques has to be used to map a very diverse landscape. Researchers can only very recently benefit from free software for calculation of advanced visualization techniques. These tools are often difficult to understand, have numerous options that confuse the user, or require and produce non-standard data formats, because they were written for specific purposes. We therefore designed the Relief Visualization Toolbox (RVT) as a free, easy-to-use, standalone application to create visualisations from high-resolution digital elevation data. It is tailored for the very beginners in relief interpretation, but it can also be used by more advanced users in data processing and geographic information systems. It offers a range of techniques, such as simple hillshading and its derivatives, slope gradient, trend removal, positive and negative openness, sky-view factor, and anisotropic sky-view factor. All included methods have been proven to be effective for detection of small scale features and the default settings are optimised to accomplish this task. However, the usability of the tool goes beyond computation for visualization purposes, as sky-view factor, for example, is an essential variable in many fields, e.g. in meteorology. RVT produces two types of results: 1) the original files have a full range of values and are intended for further analyses in geographic information systems, 2) the simplified versions are histogram stretched for visualization purposes and saved as 8-bit GeoTIFF files. This means that they can be explored in non-GIS software, e.g. with simple picture viewers, which is essential when a larger community of non-specialists needs to be considered, e.g. in public collaborative projects. The tool recognizes all frequently used single band raster formats and supports elevation raster file data conversion.

  9. DEM Solutions Develops Answers to Modeling Lunar Dust and Regolith

    NASA Technical Reports Server (NTRS)

    Dunn, Carol Anne; Calle, Carlos; LaRoche, Richard D.

    2010-01-01

    With the proposed return to the Moon, scientists like NASA-KSC's Dr. Calle are concerned for a number of reasons. We will be staying longer on the planet's surface, future missions may include dust-raising activities, such as excavation and handling of lunar soil and rock, and we will be sending robotic instruments to do much of the work for us. Understanding more about the chemical and physical properties of lunar dust, how dust particles interact with each other and with equipment surfaces and the role of static electricity build-up on dust particles in the low-humidity lunar environment is imperative to the development of technologies for removing and preventing dust accumulation, and successfully handling lunar regolith. Dr. Calle is currently working on the problems of the electrostatic phenomena of granular and bulk materials as they apply to planetary surfaces, particularly to those of Mars and the Moon, and is heavily involved in developing instrumentation for future planetary missions. With this end in view, the NASA Kennedy Space Center's Innovative Partnerships Program Office partnered with OEM Solutions, Inc. OEM Solutions is a global leader in particle dynamics simulation software, providing custom solutions for use in tackling tough design and process problems related to bulk solids handling. Customers in industries such as pharmaceutical, chemical, mineral, and materials processing as well as oil and gas production, agricultural and construction, and geo-technical engineering use OEM Solutions' EDEM(TradeMark) software to improve the design and operation of their equipment while reducing development costs, time-to-market and operational risk. EDEM is the world's first general-purpose computer-aided engineering (CAE) tool to use state-of-the-art discrete element modeling technology for the simulation and analysis of particle handling and manufacturing operations. With EDEM you'can quickly and easily create a parameterized model of your granular solids system. Computer-aided design (CAD) models of real particles can be imported to obtain an accurate representation of their shape. EDEM(TradeMark) uses particle-scale behavior models to simulate bulk solids behavior. In addition to particle size and shape, the models can account for physical properties of particles along with interaction between particles and with equipment surfaces and surrounding media, as needed to define the physics of a particular process.

  10. Coronal Response to an EUV Wave from DEM Analysis

    NASA Astrophysics Data System (ADS)

    Vanninathan, K.; Veronig, A. M.; Dissauer, K.; Madjarska, M. S.; Hannah, I. G.; Kontar, E. P.

    2015-10-01

    Extreme-Ultraviolet (EUV) waves are globally propagating disturbances that have been observed since the era of the Solar and Heliospheric Observatory/Exteme-ultraviolet Imaging Telescope instrument. Although the kinematics of the wave front and secondary wave components have been widely studied, there is not much known about the generation and plasma properties of the wave. In this paper we discuss the effect of an EUV wave on the local plasma as it passes through the corona. We studied the EUV wave, generated during the 2011 February 15 X-class flare/coronal mass ejection event, using Differential Emission Measure diagnostics. We analyzed regions on the path of the EUV wave and investigated the local density and temperature changes. From our study we have quantitatively confirmed previous results that during wave passage the plasma visible in the Atmospheric Imaging Assembly (AIA) 171 Å channel is getting heated to higher temperatures corresponding to AIA 193 and 211 Å channels. We have calculated an increase of 6%–9% in density and 5%–6% in temperature during the passage of the EUV wave. We have compared the variation in temperature with the adiabatic relationship and have quantitatively demonstrated the phenomenon of heating due to adiabatic compression at the wave front. However, the cooling phase does not follow adiabatic relaxation but shows slow decay indicating slow energy release being triggered by the wave passage. We have also identified that heating is taking place at the front of the wave pulse rather than at the rear. Our results provide support for the case that the event under study here is a compressive fast-mode wave or a shock.

  11. Schlusswort

    NASA Astrophysics Data System (ADS)

    Pfeffer, Michael; Reinhardt, Andreas

    Im Rahmen des BMBF-Verbundprojektes ProMoLeS wurde bereits zu Projektbeginn der Industriearbeitskreis Montagelösungen für die Leistungselektronik" gegründet, welcher unter der organisatorischen und fachlichen Leitung vom bayerischen Cluster Leistungselektronik im ECPE e.V. eine Plattform für den Austausch zwischen Unternehmen der Leistungselektronik bietet. Ziel des Industriearbeitskreises ist es daher, mit neuen und innovativen Lösungen einen Beitrag zur Sicherung der Montagearbeitsplätze am Standort Deutschland zu leisten. Der Arbeitskreis richtet sich an Fach- und Führungskräfte von Unternehmen, die leistungselektronische Systeme oder deren Komponenten entwickeln und herstellen: Entwicklungsingenieure, Fertigungsplaner, Fertigungstechnologen, Fertigungsleiter, Arbeitsorganisatoren, Qualitätsbeauftragte sowie Wissenschaftler an Hochschulen, die auf den genannten Gebieten arbeiten. Ziel und Zweck des Arbeitskreises ist es, Wissen und Erfahrung auszutauschen, persönliche Kontakte von Fachleuten zwischen Unternehmen und wissenschaftlichen Einrichtungen zu verstärken, Kooperationen in dem Gebieten der Entwicklung, Fertigung, Logistik oder Qualifizierung aufzubauen, strategisch relevante Themen zu erkennen und gemeinsame Forschungs- und Entwicklungsprojekte zu initiieren. Damit soll die Wettbewerbsfähigkeit der Unternehmen verbessert und Arbeitsplätze am Standort gesichert werden.

  12. Semantic Web Revisited - Eine kurze Einführung in das Social Semantic Web

    NASA Astrophysics Data System (ADS)

    Blumauer, Andreas; Pellegrini, Tassilo

    Während in den vergangenen Monaten Themen wie Web 2.0 und Social Software ein erstaunliches Konjunkturhoch erlebt haben, vollzieht sich weitgehend abseits der öffentlichen Wahrnehmung eine technologische Komplementärinnovation. Die wachsende Adaption semantischer Technologien zu Zwecken der strukturierten Erschließung von Web 2.0 Content", aber auch der Einsatz von Social Software zur kollaborativen Anreicherung von Web Content mit maschinenlesbaren Metadaten sind Ausdruck eines Trends in Richtung Social Semantic Web". Bezeichnendes Merkmal dieser Entwicklung ist die voranschreitende Konvergenz zwischen Social Software und Semantic Web Technologien. Dieser Beitrag hat das Ziel ein allgemeines Bewusstsein und Verständnis dieser Entwicklung zu schaffen und nähert sich dem Phänomen aus einer nichttechnischen Perspektive.

  13. Cyber-Physical Systems - Wissenschaftliche Herausforderungen Bei Der Entwicklung

    NASA Astrophysics Data System (ADS)

    Broy, Manfred

    Cyber-Physical Systems adressieren die enge Verbindung eingebetteter Systeme zur Überwachung und Steuerung physikalischer Vorgänge mittels Sensoren und Aktuatoren über Kommunikationseinrichtungen mit den globalen digitalen Netzen (dem Cyberspace"). Dieser Typus von Systemen ermöglicht über Wirkketten eine Verbindung zwischen Vorgängen der physischen Realität und den heute verfügbaren digitalen Netzinfrastrukturen. Dies erlaubt vielfältige Applikationen mit hohem wirtschaftlichen Potential, und mit starker Innovationskraft. Die vollständige Ausschöpfung des Potentials erfordert aber gezielte wissenschaftliche Anstrengungen bei der Entwicklung solcher Systeme im Hinblick auf Methodik, Technologie, Kostenbeherrschung und funktionale Angemessenheit.

  14. Einfluss des Internets auf das Informations-, Einkaufs- und Verkehrsverhalten

    NASA Astrophysics Data System (ADS)

    Nerlich, Mark R.; Schiffner, Felix; Vogt, Walter

    Mit Daten aus eigenen Erhebungen können das einkaufsbezogene Informations- und Einkaufsverhalten im Zusammenhang mit den verkehrlichen Aspekten (Distanzen, Verkehrsmittel, Wegekopplungen) dargestellt werden. Die Differenzierung in die drei Produktkategorien des täglichen, mittelfristigen und des langfristigen Bedarfs berücksichtigt in erster Linie die Wertigkeit eines Gutes, die seine Erwerbshäufigkeit unmittelbar bestimmt. Der Einsatz moderner IKT wie das Internet eröffnet dem Endverbraucher neue Möglichkeiten bei Information und Einkauf. Die verkehrliche Relevanz von Online-Shopping wird deutlich, wenn man berücksichtigt, dass im Mittel rund 17% aller Online-Einkäufe, die die Probanden durchgeführt haben, Einkäufe in Ladengeschäften ersetzen. Dies gilt in verstärktem Maße für Online-Informationen: etwa die Hälfte hätte alternativ im stationären Einzelhandel stattgefunden. Da der Erwerb von Gütern des täglichen Bedarfs häufig nahräumlich und in relevantem Anteil nicht-motorisiert erfolgen kann, sind in diesem Segment - im Gegensatz zum mittel- und langfristigen Bedarf - nur geringe Substitutionseffekte zu beobachten.

  15. Between handicraft and science: Friedrich Schwab (1858 - 1931). (German Title: Zwischen Handwerk und Wissenschaft: Friedrich Schwab (1858 - 1931))

    NASA Astrophysics Data System (ADS)

    Brosche, Peter; Zsoldos, Endre

    So far only fragments are known of the biography of Friedrich Schwab. Now that we were able to clear up the essentials of his life, it exhibits an exemplary character between handicraft and science. He tried to apply his talents if possible at scientific expeditions and at higher teaching institutions but did not hesitate to change positions and countries if the circumstances were unacceptable. He served astronomy in his youth as mechanic of the German Venus transit expedition 1882 to the straits of Magellan, later and preponderantly as a long standing observer of variable stars. The inspection of the literature proves that his work was received as serious by the contemporaneous professionals.

  16. Ueber einige Wechselbeziehungen zwischen Anglistik und Englischunterricht (On Some Mutual Relationships between English Philology and English Teaching).

    ERIC Educational Resources Information Center

    Finkenstaedt, Thomas

    1978-01-01

    Discusses the mutual dependence of English philology and the teaching of English as a foreign language. It is felt that the modern philologies will fall upon hard times if they try to influence language teaching with arguments better applied to the classical languages. (IFS/WGA)

  17. Zwischen Web 2.0, virtuellen Welten und Game-based Learning - Einsatzszenarien und Prototypen im Hochschulumfeld

    NASA Astrophysics Data System (ADS)

    Pongratz, Hans

    Web 2.0, virtuelle Welten und Game-based Learning werden als Allheilmittel moderner Wissensvermittlung an Hochschulen genannt. Dieser Artikel beschreibt nach einer Einführung in die Thematik Einsatzszenarien und Prototypen im Hochschulumfeld anhand ausgewählter Web 2.0-Dienste, der virtuellen Welt Second Life, eines an der TUM entwickelten Frameworks für Gamebased Learning Applikationen und eines Lernspiels. Diese werden anhand von konkreten Lehr- und Lernszenarien vorgestellt und anhand der bisherigen Erfahrungen in diesem Bereich kritisch beleuchtet.

  18. Charakterisierung von Sulfotransferasen im Gastrointestinaltrakt von Mensch und Ratte und Aktivierung von Promutagenen in V79-Zellen, die eine intestinale Form (1B1) des Menschen und der Ratte exprimieren

    NASA Astrophysics Data System (ADS)

    Teubner, Wera

    2001-05-01

    Die Ausstattung der gastrointestinalen Mukosa des Menschen und der Ratte mit Sulfotransferasen wurde mit Hilfe von Immunodetektion und Enzymaktivitätsmessungen untersucht. In Proben aus Colon und Rektum von 39 Personen wurden die Formen h1A1, h1A3 und h1B1 identifiziert, wobei in einer weiteren Probe, die als einzige von einem an Colitis Ulcerosa erkrankten Patienten stammte, keine Sulfotransferasen nachgewiesen werden konnten. Bei der Immunblot-Analyse war das Expressionsmuster der einzelnen Formen in allen Proben ähnlich. In wenigen Proben waren die relativen Signalintensitäten der h1A1 und der h1B1 um die Hälfte erniedrigt. Der Gehalt von SULT an zytosolischem Protein zeigte einen bis zu 8 - 10fachen Unterschied, er betrug jedoch bei zwei Dritteln der Proben zwischen 0,15 und 0,3 (h1A1 und h1A3) bzw. 0,6 und 0,8 Promille (h1B1). Die Variation konnte nicht auf Alter, Geschlecht oder Krankheitsbild der Patienten zurückgeführt werden. Auch der für die allelischen Varianten der h1A1 beschriebene Effekt auf die Enzymaktiviät bzw. Stabilität konnte in der Menge an immunreaktivem Protein nicht in diesem Ausma detektiert werden. Die Allelhäufigkeit von h1A1*R und h1A1*H war gegenüber der gesunden Bevölkerung nicht verändert. In den sieben Proben aus dem Dünndarm (Coecum, viermal Ileum, Jejunum) konnten zusätzlich die Formen h1E1 und h2A1 identifiziert werden. Ein möglicherweise der Form h1C1 entsprechendes Protein wurde im Magen detektiert. Im Vergleich zum Menschen war die Expression in der Ratte stärker auf die Leber konzentriert. Während beim Menschen in allen untersuchten Abschnitten Sulfotransferasen in Mengen detektiert wurden, die in zwei Fällen (h1B1 und h1A3) sogar den Gehalt in der Leber überstiegen, beschränkte sich die Expression in der Ratte auf im Vergleich zur Leber geringe Mengen im Magen und Dickdarm. Nachgewiesen wurden die r1B1, r1A1 sowie eine nicht identifizierte Form von 35kD, bei der es sich vermutlich um die r1C2 handelt. Im Vergleich zur Leber enthielt der Dickdarm der Ratte 20 - 30 % an r1B1 und 3 % an r1A1, während im Dickdarm des Menschen die 3 - 5fache Menge an h1B1 und 25 - 50 % an h1A1 gefunden wurden. Die nicht identifizierte Form verhielt sich wie die r1B1. Die für die Leber der Ratte bekannte geschlechtsabhängige Expression wurde im Gastrointestinaltrakt nicht beobachtet. Die Verteilung der Sulfotransferasen im Colon und Ileum des Menschen wurde immunhistochemisch untersucht; für die Gewebe der Ratte war die Spezifität der zur Verfügung stehenden Antiseren nicht ausreichend. Im Colon traten h1B1-spezifische Färbungen in den differenzierten Enterozyten am oberen Ende der Krypten auf, im Dünndarm wurden die Epithelzellen der Zotten gefärbt. Die Färbung konzentrierte sich auf das Zytoplasma. Eine ähnliche Verteilung zeigte sich für h1A1 und h1A3, auer da zusätzlich eine intensive Färbung der Endothelzellen der Kapillaren in der Submukosa des Ileums auftrat. Im Dickdarm war dies nur bei den Kapillaren in den Lymphfollikeln zu erkennen. Die h2A1 war lediglich im Zytoplasma der Epithelzellen der Zotten des Ileums nachzuweisen, während im Colon keine Farbreaktion auftrat. Durch die Verwendung der rekombinanten Indikatorstämme TA1538-h1A1, -h1A3 und -h1B1 und des Ausgangsstammes Salmonella typhimurium TA1538 im Ames-Test wurde gezeigt, da verschiedene benzylische und allylische Alkohole durch im humanen Colon exprimierte Sulfotransferasen zu Mutagenen aktiviert werden. In den meisten Fällen erwies sich eine der drei Sulfotransferasen als besonders effizient in der Bioaktivierung, während durch die anderen Formen kein oder nur ein schwacher Effekt verursacht wurde. Die Bioaktivierung von Promutagenen durch Sulfotransferasen im Colon mu im Zusammenhang mit der Lokalisation diskutiert werden. Die Zellen im Darm, in denen immunhistochemisch Sulfotransferasen detektiert wurden, haben mit Ausnahme des Endothels je nach Abschnitt eine Lebensdauer von maximal fünf Tagen und machen keine weiteren Zellteilungen mehr durch. Daher sind DNA-Schäden in diesen Zellen ein seh

  19. A DEM analysis of step-path failure in jointed rock slopes

    NASA Astrophysics Data System (ADS)

    Scholtès, Luc; Donzé, Frédéric V.

    2015-02-01

    A numerical analysis of step-path failure mechanisms in rock slopes is provided based upon simulations performed using a discrete element method specifically enhanced for the modeling of jointed rock masses. Fracturing of the intact rock as well as yielding within discontinuities can be simulated to determine the failure surface without any a priori assumption on its location. For both coplanar and non-coplanar sets of discontinuities, failure is the result of the propagation of tensile microcracks that develop in the rock bridges from the tips of pre-existing discontinuity planes in a way similar to wing cracks extensions that can eventually coalesce to form extended step-path failure surfaces. Sensitivity analyses are performed to better understand the critical mechanisms that lead to slope failure and to discriminate between the respective roles played by intact rock and planes of weakness at the onset of failure. For a randomly distributed set of joints that share the same preferential orientation, failure is shown to be dependent on the frictional strength mobilized on the joint surfaces. The results confirm the critical need for a comprehensive and extensive characterization of both mechanical and geometrical properties of discontinuities when assessing the stability of a rock mass.

  20. Structural Analysis of Central Luzon, Philippines, Using Shuttle Radar Topography Mission DEM

    NASA Astrophysics Data System (ADS)

    Torres, R.; Mouginis-Mark, P.; Garbeil, H.; Bautista, L.; Ramos, E.

    2002-12-01

    Central Luzon Island (13-16°N, 120-122°E), which is bounded to the east by Philippine Trench, to the west by Manila Trench, to the north by Digdig-Dingalan Fault (DDF) and to the south by Verde Island Passage Fault (VIPF), is one of the most seismically and volcanologically active regions in the Philippines. Active seismicity and violent earthquakes in the region are evidently related to the activities along the subduction zones and branches of the Philippine Fault system. Volcanic eruptions and periodic swarms of volcanic earthquakes were also observed in three active volcanoes, i.e., Pinatubo, Taal Volcano Island and Banahaw, while young calderas of Taal and Laguna de Bay are demonstrably fault-bounded. We use the Shuttle Radar Topography Mission (SRTM) data with 90 m spatial resolution to conduct regional mapping of the faults and volcanic structures in this region. Of particular interests are the NE-SW set of normal faults within the Macolod Corridor, the right-lateral Marikina Valley Fault System (MVFS), the prevalence of N-S trending structures and the series of NW-SE structures that parallel to sub-parallel the active branches of the Philippine Fault. Using ENVI software package, we processed the SRTM data into shaded relief images and examined the lineament features from different azimuth directions and angles of artificial illumination. The prominent NW-SE structures in this area revealed by SRTM data were formed as sinistral shears that parallel the seismically active DDF and VIPF. The N-S trending structures, including some segments of MVFS and N-S oriented fold axes, were apparently generated by an earlier E-W compression, but recently displayed dextral movement with localized vertical component and pull-apart zones. The overprinting of recent fault kinematics on previously formed structures suggest a dramatic shift of regional stress distribution in Central Luzon. The dextral movement along MVFS and the extensional NE-SW faults within the Macolod Corridor are consistent with the regional deformation due to coupling of DDF and VIPF movements. Similarly, the E-W to ENE-WSW and N-S to NNE-SSW structures probably formed as Riedel and anti-Riedel shears.

  1. Automatic Dem Generation And 3D Change Detection From Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Krauß, Thomas; d'Angelo, Pablo; Tian, Jiaojiao; Reinartz, Peter

    2013-12-01

    In this paper we present a method for fully automatic generation of digital surface models (DSM) from very high resolution (VHR) satellite imagery and the consecutively automatic change detection from the derived 3D information. Common change detection methods are normally only based on spectral change detection. These methods will fail for e.g. comparing summer and winter scenes with the latter covered with snow. Introducing the digital elevation model into the change detection process will allow for a more detailled object modeling and also for the possibility to detect more sophisticated changes like volume estimation of mining activities. Here we present the involved methods for the generation of the high resolution surface models, the fusion and classification and finally the automatic 3D change detection. The methods are applied to some VHR stereo test data sets and the results are evaluated for quality and usefulness for automatic information derivation from large data sets.

  2. Proprocessing: Geocoding of AVIRIS Data Using Navigation, Engineering, DEM, and Radar Tracking System Data

    NASA Technical Reports Server (NTRS)

    Meyer, P.; Larson, S. A.; Hansen, E. G.; Itten, K. I

    1993-01-01

    Remotely sensed data have geometric characteristics and representation which depend on the type of the acquisition system used. To correlate such data over large regions with other real world representation lools like conventional maps or Geographic Information Systems (GIS) for verification purposes, or for further treatment within different data sets, a coregistration has to be performed.

  3. Preprocessing: Geocoding of AVIRIS data using navigation, engineering, DEM, and radar tracking system data

    NASA Technical Reports Server (NTRS)

    Meyer, Peter; Larson, Steven A.; Hansen, Earl G.; Itten, Klaus I.

    1993-01-01

    Remotely sensed data have geometric characteristics and representation which depend on the type of the acquisition system used. To correlate such data over large regions with other real world representation tools like conventional maps or Geographic Information System (GIS) for verification purposes, or for further treatment within different data sets, a coregistration has to be performed. In addition to the geometric characteristics of the sensor there are two other dominating factors which affect the geometry: the stability of the platform and the topography. There are two basic approaches for a geometric correction on a pixel-by-pixel basis: (1) A parametric approach using the location of the airplane and inertial navigation system data to simulate the observation geometry; and (2) a non-parametric approach using tie points or ground control points. It is well known that the non-parametric approach is not reliable enough for the unstable flight conditions of airborne systems, and is not satisfying in areas with significant topography, e.g. mountains and hills. The present work describes a parametric preprocessing procedure which corrects effects of flight line and attitude variation as well as topographic influences and is described in more detail by Meyer.

  4. Simulations of Fracture and Fragmentation of Geologic Materials using Combined FEM/DEM/SPH Analysis

    SciTech Connect

    Morris, J P; Johnson, S M

    2007-04-05

    An overview of the Lawrence Discrete Element Code (LDEC) is presented, and results from a study investigating the effect of explosive and impact loading on geologic materials using the Livermore Distinct Element Code (LDEC) are detailed. LDEC was initially developed to simulate tunnels and other structures in jointed rock masses using large numbers of polyhedral blocks. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model this class of problems, LDEC now includes implementations of Cosserat point theory and cohesive elements. This approach directly simulates the transition from continuum to discontinuum behavior, thereby allowing for dynamic fracture within a combined finite element/discrete element framework. In addition, a Smooth Particle Hydrodynamics (SPH) capability has been incorporated into LDEC, permitting the simulation of fluid-structure interaction. We will present results from a study of detonation-induced fracture and fragmentation of geologic media surrounding a tunnel using LDEC.

  5. SLOPE STABILITY ANALYSIS OF THE ILIAMNA VOLCANO, ALASKA, USING ASTER TIR, SRTM DEM, AND AEROMAGNETIC DATA

    E-print Network

    using Iliamna, Alaska as a case study. ASTER and SRTM data were processed and scaled, then a script areas at risk for slope failure, which correlate well to the geologic field studies. These scripts can study. In order to classify potential volcano hazard areas the Alaskan Volcano Observatory, a joint

  6. Ökophysik: Plaudereien über das Leben auf dem Land, im Wasser und in der Luft

    NASA Astrophysics Data System (ADS)

    Nachtigall, W.

    Prof. em. Dr. rer. nat. Werner Nachtigall, geb. 1934, war als Zoophysiologe und Biophysiker Leiter des Zoologischen Instituts der Universität des Saarlandes in Saarbrücken. In Forschung und Ausbildung hat er sich insbesondere mit Aspekten der Technischen Biologie und Bionik befasst und mit seinen Forschergruppen viele Basisdaten insbesondere zur Ökologie, Physiologie und Physik des Fliegens und Schwimmens aber auch zur Stabilität beispielsweise der Gräser erarbeitet. Lebewesen überraschen immer wieder durch ihre "Biodiversität", ihre hochspezifischen Ausgestaltungen und Anpassungen.

  7. Simulations of Fracture and Fragmentation of Geologic Materials using Combined FEM/DEM Analysis

    SciTech Connect

    Morris, J P; Rubin, M B; Block, G I; Bonner, M P

    2005-05-26

    Results are presented from a study investigating the effect of explosive and impact loading on geological media using the Livermore Distinct Element Code (LDEC). LDEC was initially developed to simulate tunnels and other structures in jointed rock masses with large numbers of intact polyhedral blocks. However, underground structures in jointed rock subjected to explosive loading can fail due to both rock motion along preexisting interfaces and fracture of the intact rock mass itself. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model these types of problems, we have implemented Cosserat point theory and cohesive element formulations into the current version of LDEC, thereby allowing for dynamic fracture and combined finite element/discrete element simulations. Results of a large-scale LLNL simulation of an explosive shock wave impacting an elaborate underground facility are also discussed. It is confirmed that persistent joints lead to an underestimation of the impact energy needed to fill the tunnel systems with rubble. Non-persistent joint patterns, which are typical of real geologies, inhibit shear within the surrounding rock mass and significantly increase the load required to collapse a tunnel.

  8. The regular shape of stratovolcanoes: A DEM-based morphometrical approach

    NASA Astrophysics Data System (ADS)

    Karátson, Dávid; Favalli, Massimiliano; Tarquini, Simone; Fornaciai, Alessandro; Wörner, Gerhard

    2010-06-01

    We studied the shape of the most regular-shaped stratovolcanoes of the world to mathematically define the form of the ideal stratovolcano. Based on the Shuttle Radar Topographic Mission data we selected 19 of the most circular and symmetrical volcanoes, which incidentally all belong to subduction-related arcs surrounding the Pacific. The selection of volcanoes benefitted from the introduction of a new definition of circularity which is more robust than previous definitions, being independent of the erosional dissection of the cone. Our study on the shape of stratovolcanoes was based on the analysis of the radial elevation profiles of each volcano. The lower half section of the volcanoes is always well fitted by a logarithmic curve, while the upper half section is not, and falls into two groups: it is fitted either by a line ("C-type", conical upper part) or by a parabolic arc ("P-type", parabolic/concave upper part). A quantitative discrimination between these groups is obtained by fitting their upper slope with a linear function: C-type volcanoes show small, whereas P-type volcanoes show significant negative angular coefficient. The proposed threshold between the two groups is - 50 × 10 - 4 °/m. Chemical composition of eruptive products indicates higher SiO 2 and/or higher H 2O content for C-type volcanoes, which could imply a higher incidence of mildly explosive (e.g. strombolian) eruptions. We propose that this higher explosivity is responsible for forming the constant uppermost slopes by the deposition of ballistic tephra and its subsequent stabilisation at a constant angle. By contrast, P-type volcanoes are characterized by a smaller SiO 2 and H 2O content, which can be responsible for a higher incidence of effusive events and/or a lower incidence of upper flank-forming (i.e. mild) explosive eruptions. Therefore, the concave upper flanks of these volcanoes may be shaped typically by lava flows. Based on this hypothesis, we propose that the morphometric analysis of the elevation profile of stratovolcanoes can provide insights into their dominant eruptive style.

  9. Ein Ort, an dem unangenehme Zeitgenossen wie Chlamydien, HI-Viren oder Tuberkulosebakterien im Zentrum stehen

    E-print Network

    Falge, Eva

    -Campus in Berlin liegt, nur wenige Schritte ent- fernt von der Luisenstraße, wo Robert Koch 1882 den MaxPlanckForschung 57 #12;Immer und immer wieder hatte Robert Koch gegen Ende des 19. Jahrhunderts

  10. Michael Zimmer’s Diary: Ein deutsches Tagebuch aus dem Amerikanischen Biirgerkrieg

    E-print Network

    Keel, William

    2005-01-01

    American word would be produced as in Hambold or Hambolt (17; for the town of Humboldt, Kansas), which would correspond more to the American pronunciation when read out loud than the German pronunciation of the baron s actual name. The original German... FOR GERMAN-AMERICAN STUDIES and THE JOYCE AND ELIZABETH HALL CENTER FOR THE HUMANITIES TABLE OF CONTENTS From the Editor ix DonalfF. Durnbaugh: In Memoriam 1 INTRODUCTORY ESSAY Frank Baron German Republicans and Radicals in the Struggle for a Slave...

  11. Quantification of Terrain Ruggedness as a Predictor of DEM Interpolation Error 

    E-print Network

    Coursey, Luke

    2013-11-20

    Interpolation of elevation data is a common step for creation and reformatting of many digital elevation products, which involves the estimation of unknown surface values based on surrounding measurements. Hydrological and ...

  12. Ecology and behavior of reintroduced Hawaiian Geese Von dem Fachbereich Biologie

    E-print Network

    Black, Jeff

    of Forestry and Wildlife, the National Biological Survey, and Sandy and Jill Friedman, Honolulu, for financial and Susanne Strauß were of invaluable assistance. My work on the State-wide database was only possible through

  13. Political Participation of Non-Citzens in Germany and Western Europe. (Beitrage aus dem Fachbereich Padagogik).

    ERIC Educational Resources Information Center

    Reuter, Lutz R.

    This paper compares the present social, economic, and political rights labor immigrants enjoy within the European Community (EC). Its focus is the current debate about the municipal suffrage of permanent residents. The dual relevance of the topic is obvious. EC bodies like the Commission, Council of Ministers, Political Council, and European…

  14. A Study of a DEM-Based Granular Dynamics Solver M.Sc Candidate

    E-print Network

    Toronto, University of

    , sand or powders) is a challenging mathematical and computational problem. Our observation such as sand, dust or powders exhibit behaviors that is incompletely described by existing solid, liquid or gas freestanding shape, flow like liquids and move in a cohesive unit or expand like gases and evolve with complex

  15. CFD-DEM modelling of two-phase pneumatic conveying with experimental validation. 

    E-print Network

    Ebrahimi, Mohammadreza

    2014-11-27

    A wide range of industrial processes involve multiphase granular flows. These include catalytic reactions in fluidized beds, the pneumatic conveying of raw materials and gas-particle separators. Due to the complex nature ...

  16. http://gedenkbuch.univie.ac.at Das Projekt besteht aus dem

    E-print Network

    Pottmann, Helmut

    - sität Wien aufbewahrt wird, sowie aus der gleichnamigen Online-Datenbank. Es umfasst derzeit rund 1 of the University of Vienna were dismissed and subsequently driven away and/or murdered for "racial and/or political

  17. MURGANGAKTIVITT AUF EINEM BEWALDETEN KEGEL DER SCHWEIZER ALPEN SEIT DEM SPTEN HOLOZN

    E-print Network

    Butler, David R. - Department of Geography, Texas State University

    , Larix decidua Mill., Picea abies (L.) Karst., Pinus cembra L. ABSTRACT The study of 1102 trees growing, seasonality, triggers, dendrogeomorphology, tree ring, Larix decidua Mill., Picea abies (L.) Karst., Pinus

  18. Die Darstellung von Außenseitern in Klaus Manns Erzählungen aus dem Exil

    E-print Network

    Kroh, Regine

    2008-05-20

    This thesis is concerned with the analysis of the depiction of outsiders in Klaus Mann's stories that were written in exile. Based on a sociological and literary definition of the term "outsider," this study investigates ...

  19. SPH-DEM simulations of grain dispersion by liquid injection Martin Robinson

    E-print Network

    Luding, Stefan

    for this and other problems involving a free (liquid- gas) surface and a partly immersed particle phase. Our and dams. Industrially, the dispersion of solid particles in a liquid is of broad relevance for chemical- cess. However, we wish to focus in this work only on the case in which the liquid-solid interfacial

  20. FEM-DEM Simulation of Two-way Fluid-Solid Interaction in Fibrous Porous Media

    E-print Network

    Luding, Stefan

    in chemical engineering, mechanical engineering unit- processes like silos, mixers, ball-mills, or conveyor many parameters such as particle size/spatial distribution, particle shape, and orientation, etc

  1. Verification and validation of a DEM-CFD model and multiscale modelling of cohesive fluidization regimes 

    E-print Network

    Gupta, Prashant

    2015-06-29

    Fluidization of solid particles using gas flow is an important process in chemical and pharmaceutical industries. The dynamics of fluidisation are intricately related to particle scale physics. Fluid-particle interactions ...

  2. Calibration of DEM models for granular materials using bulk physical tests 

    E-print Network

    Johnstone, Mical William

    2010-01-01

    to develop the methodology including 3 inorganic solids (single and paired glass beads, and polyethylene terephthalate pellets) and two organic materials (black eyes beans and black kidney beans). The developed methodology consists of three steps: 1...

  3. Grundlagen II: Variablen, Werte, Typen, Strukturen Softwareentwicklungspraktikum "Python mit dem Raspberry Pi"

    E-print Network

    Raspberry Pi" (WiSe 2015/2016) Clemens Schefels Lehr- und Forschungseinheit f¨ur Programmier- und;Dictionary Beispiele f¨ur Schl¨ussel/Wert Paare 1 >>> abkuerzung = {"Raspi" : "Raspberry Pi", 2 "S2: 2 print("Hallo Raspberry") 20 / 37 #12;Schleifen ­ Programmbeispiel Programm-Beispiel Beispiel

  4. Dynamic simulations of geologic materials using combined FEM/DEM/SPH analysis

    SciTech Connect

    Morris, J P; Johnson, S M

    2008-03-26

    An overview of the Lawrence Discrete Element Code (LDEC) is presented, and results from a study investigating the effect of explosive and impact loading on geologic materials using the Livermore Distinct Element Code (LDEC) are detailed. LDEC was initially developed to simulate tunnels and other structures in jointed rock masses using large numbers of polyhedral blocks. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model this class of problems, LDEC now includes implementations of Cosserat point theory and cohesive elements. This approach directly simulates the transition from continuum to discontinuum behavior, thereby allowing for dynamic fracture within a combined finite element/discrete element framework. In addition, there are many application involving geologic materials where fluid-structure interaction is important. To facilitate solution of this class of problems a Smooth Particle Hydrodynamics (SPH) capability has been incorporated into LDEC to simulate fully coupled systems involving geologic materials and a saturating fluid. We will present results from a study of a broad range of geomechanical problems that exercise the various components of LDEC in isolation and in tandem.

  5. Processes of mass loss on a debris covered glacier determined by high resolution DEM differencing

    NASA Astrophysics Data System (ADS)

    Thompson, Sarah; Benn, Doug I.; Mertes, Jordan

    2015-04-01

    In recent years the response of debris-covered glaciers to climatic warming has seen significant disscussion. The insulating properties of a debris layer (> 5-6 cm) are well established however, in the Himalayas regionally averaged thinning rates, based on satellite laser altimetry, were found to be very similar on both debris-covered, and clean ice glaciers in the Himalayas. Overall mass loss rates on large debris covered glaciers have been discussed in conjunction with supraglacial lake development and growth but the processes involved in downwasting are often numerous and complex. Here we report on mass loss measurements, from a combination of in situ lake surveys and remote sensing, on large debris covered glacier in the Khumbu Himal Nepal. Lake bathymetry sonar surveys were conducted in the winter of 2009 and 2012, and GeoEye-1 stereo imagery was acquired in 2010 and 2012. The temporal data sets were combined and differencd to allow detailed investigation of glacial surface change over the 2 year period. Ngozumpa Glacier has a stagnant ice tongue extending down to ~4650 m asl, the lower 15 km of which is debris covered. This debris covered region is highly irregular with many hollows occupied by studded with numerous supraglacial ponds and lakes. In the early 1990s a base level lake was identified ~1 km from the glacier terminus. Our results show a highly complex pattern of glacial downwasting and lake change. Numerous examples of rapid supra glacial growth and drainage are evident, including the formation and enlargement of lakes along preexisting structures such as relic englacial drainage conduits. However, also in evidence are areas of significant lake shrinkage due to sedimentation and lake shore debris collapse. In addition to lake induced mass loss a background downwasting rate of ~ 0.5 m a-1 is evident in the lower ablation area where debris thicknesses are known to be between 1-3 m thick. The results illustrate the highly complex nature of debris covered glacier evolution and the myriad processes involved.

  6. Micro-mechanical study of stress path and initial conditions in granular materials using DEM

    NASA Astrophysics Data System (ADS)

    Dorostkar, Omid; Mirghasemi, Ali Asghar

    2015-10-01

    The macroscale response of granular materials under different loading conditions stems from the alteration of micromechanical properties during loading. Previous studies have used either physical experiments or discrete element method simulations to explore the effect of initial conditions and stress path on granular materials. However, microscale studies are not sufficient, especially for various loading paths. We study micromechanics of granular materials using the stress-force-fabric (SFF) relationship for a better understanding of the behavior of granular materials. Triaxial compression and extension tests are conducted on samples containing 1000 spherical particles, with periodic boundaries, and the effect of initial porosity is studied. In the next step, using the SFF relationship, we study the effect of anisotropic consolidation ratio. In addition to providing an appropriate explanation for shear strength out of evolution of anisotropy coefficients, our results show that anisotropic consolidation does not affect the micromechanical properties of granular materials in a way to change mobilized friction angle of sample at failure point.

  7. DEM code-based modeling of energy accumulation and release in structurally heterogeneous rock masses

    NASA Astrophysics Data System (ADS)

    Lavrikov, S. V.; Revuzhenko, A. F.

    2015-10-01

    Based on discrete element method, the authors model loading of a physical specimen to describe its capacity to accumulate and release elastic energy. The specimen is modeled as a packing of particles with viscoelastic coupling and friction. The external elastic boundary of the packing is represented by particles connected by elastic springs. The latter means introduction of an additional special potential of interaction between the boundary particles, that exercises effect even when there is no direct contact between the particles. On the whole, the model specimen represents an element of a medium capable of accumulation of deformation energy in the form of internal stresses. The data of the numerical modeling of the physical specimen compression and the laboratory testing results show good qualitative consistency.

  8. Nr. 272 // 2013 // 29. Oktober 2013 Physik studieren noch vor dem Studium?

    E-print Network

    Dettweiler, Michael

    an der Uni Bayreuth! Schülerinnen und Schüler vom Augustinus- Gymnasium in Weiden bestehen ihre erste Prüfung in Physik an der Universität Bayreuth Sieben Schülerinnen und Schüler vom Augustinus-Gymnasium im Weidener Schülerinnen und Schüler vom Augustinus-Gymnasium freuen sich über ihre Urkunde zur bestandenen

  9. Zwischen Wollen, aber nicht können und Können, aber nicht wollen: Übergangsprobleme von Jugendlichen in Japan am Beispiel der „Freeter`` und „NEETs``

    NASA Astrophysics Data System (ADS)

    Eswein, Mikiko; Pilz, Matthias

    2012-08-01

    Caught between wanting but not being able to, and being able, but not wanting to: Transitional problems among Japanese youths based on the examples of "Freeters" and "NEETs" - The study of processes of transition from the education system to employment is particularly important in light of youth unemployment. In Japan this transition process is often declared to be successful. In recent years, however, numerous signs have indicated a change in the situation. This article analyses this problem based on the examples of two Japanese social groups, "Freeters" and "NEETs". These terms refer to young adults who do not immediately move into to regular employment. The article begins by analysing the causes, then comments on education policy measures undertaken to tackle the issue. Drawing on scientifically grounded models it is shown that both social groups are characterised by meagre formal school qualifications. Social background, by contrast, is not particularly relevant; although there are hints that parents' financial means play an increasingly important role in determining whether a young person attends a high-level educational institution. Although public opinion in Japan frequently attributes values and attitudes to these groups that deviate from the norm, this is not conclusively supported by existing empirical findings. Consequently, the reasons for these transitional problems tend to be perceived as being connected to the difficult labour market situation resulting from the ongoing economic crisis. In addition to certain education policy initiatives, Japan will therefore rely heavily in future on the ability to effectively manage the integration of its shrinking cohorts of school and university graduates.

  10. Zwischen "Fassade" und "wirklicher Absicht": Eine Betrachtung uber die dritte Erziehungsreform in Japan = Between "Facade" and "Real Intent": Observations on Japan's Third Educational Reform.

    ERIC Educational Resources Information Center

    Ito, Toshiko

    1997-01-01

    Asserts that the Japanese educational system consists of the "facade" of ministerially-decreed harmony and the "real intent" of competition. Argues that the balance between the two has been endangered by recent reforms that seek to promote "creativity and diversification." Suggests that policymakers did not analyze factors that might impede…

  11. Zwischen Gesetz und Fall. Mutmassungen uber Typologien als Padagogische Wissensform (Between General Law and the Individual Case. Conjectures Concerning Typologies as a Form of Pedagogical Knowledge).

    ERIC Educational Resources Information Center

    Herzog, Walter

    2003-01-01

    Considers the mediation between scientific knowledge and practical action as a crucial feature of professional teaching. Investigates the assumption that typologies represent a form of knowledge which can bridge the gap between theory and practice. Differentiates between two forms of typological thinking and discusses reservations concerning…

  12. "Astronomica" in the Correspondence between Leonhard Euler and Daniel Bernoull (German Title: "Astronomica" im Briefwechsel zwischen Leonhard Euler und Daniel Bernoulli)

    NASA Astrophysics Data System (ADS)

    Verdun, Andreas

    2010-12-01

    The Euler Commission of the Swiss Academy of Sciences intends to terminate the edition of Leonhard Euler's works in the next year 2011 after nearly one hundred years since the beginning of the editorial works. These works include, e.g., Volume 3 of the Series quarta A which will contain the correspondence between Leonhard Euler (1707-1783) and Daniel Bernoulli (1700-1783) and which is currently being edited by Dr. Emil A. Fellmann (Basel) and Prof. Dr. Gleb K. Mikhailov (Moscow). This correspondence contains more than hundred letters, principally from Daniel Bernoulli to Euler. Parts of this correspondence were published uncommented already in 1843. It is astonishing that, apart from mathematics and physics (mainly mechanics and hydrodynamics), many topics addressed concern astronomy. The major part of the preserved correspondence between Euler and Daniel Bernoulli, in which astronomical themes are discussed, concerns celestial mechanics as the dominant discipline of theoretical astronomy of the eighteenth century. It was triggered and coined mainly by the prize questions of the Paris Academy of Science. In more than two thirds of the letters current problems and questions concerning celestial mechanics of that time are treated, focusing on the lunar theory and the great inequality in the motions of Jupiter and Saturn as special applications of the three body problem. In the remaining letters, problems concerning spherical astronomy are solved and attempts are made to explain certain phenomena in the field of "cosmic physics" concerning astronomical observations.

  13. A review of "Orthodoxie als Konsensbildung. Das theologische Disputationswesen an der Universitat Wittenberg zwischen 1570 und 1710" by Kenneth G. Appold 

    E-print Network

    Boettcher, Susan R.

    2007-01-01

    and structure of the art of disputation as practiced at the University of Wittenberg, the leading Lutheran university of the sixteenth century. The narrative begins with Jakob Andreae?s inaugural lecture in 1577, just after the purge of crypto- Calvinist... scholars from Wittenberg theological faculty. Appold traces Andreae?s efforts, with Saxon Elector August I, to establish a new method of theologi- cal education and its outcomes for the practice of disputations. Interest in disputations waxed and waned...

  14. Dateiformate für Audio

    NASA Astrophysics Data System (ADS)

    Petermichl, Karl

    Ein Dateiformat definiert die Anordnung und die Bedeutung von Werten innerhalb einer Datei. Dies reicht von inhaltsbeschreibenden Parametern bis zum Adressbereich der eigentlichen Audiodaten. Bedingt durch historische Entwicklungen und anwendungsspezifische Erfordernisse kommt in der Audiotechnik eine große Vielfalt von Formaten und Datenstrukturen zum Einsatz. In der Regel handelt es sich um Binärdateien; Textdateien können aufgrund des eingeschränkten Wertebereiches nur für sehr kleine Datensätze verwendet werden. Wesentlich ist die Unterscheidung zwischen dem Dateiformat und der Kodierung der im File enthaltenen Audiosignale. Je nach Intention der Entwickler wird schon bei der Entwicklung eines Dateiformats festgelegt, ob es nur zur Speicherung einer bestimmten Kodierung genutzt werden kann, oder ob die Option besteht, unterschiedliche Audioformate im gleichen Dateiformat abzuspeichern. Damit wird in vielen Fällen auch eine Einteilung in "lineare“ und "datenreduzierte“ Dateiformate unmöglich, vielmehr muss eine Datei auf ihre Möglichkeiten und den tatsächlichen Inhalt überprüft werden, bevor eine Aussage zulässig ist.

  15. Differenzialdiagnosen, Simulatoren und ungewöhnliche Formen des Kontaktekzems.

    PubMed

    Kränke, Birger; Schuster, Christian

    2015-11-01

    Wie alle Ekzemkrankheiten sind sowohl das irritative als auch das allergische Kontaktekzem primär über ihr morphologisches Erscheinungsbild "Ekzem" definiert. Zusätzlich gilt aber als unabdingbar für die Diagnosestellung, dass sie als spezifisches Reaktionsmuster an Haut (und Schleimhaut) erst durch den direkten oder indirekten Kontakt mit einem Allergen oder Irritans ausgelöst werden. In der Theorie und im Lehrbuch lassen sich die für ein Ekzem typischen Charakteristika einfach beschreiben, doch in der täglichen Praxis können die Erscheinungsbilder vielfältig und durchaus uncharakteristisch sein: Kontaktreaktionen können auch lichenoid, lymphomatoid, granulomatös, pigmentiert, purpurisch oder multiforme-artig auftreten und somit das eigentlich typische "Ekzembild" vermissen lassen. Dadurch wird der Kreis der zu berücksichtigenden Differenzialdiagnosen deutlich erweitert. Komplizierend kommt hinzu, dass eine signifikante Zahl an Auslösern, die nicht über einen Kontaktmechanismus krankheitsauslösend wirken, unerwünschte Reaktionen entsprechend der Morphologie eines Ekzems und dem Verteilungsmuster eines Kontaktekzems auslösen können. In diesem Zusammenhang sind vor allem Medikamente und hier besonders die zunehmend in der Onkologie verwendeten Kinaseblocker zu nennen. Die Kenntnis dieser Zusammenhänge ist essentiell für die adäquate diagnostische wie auch therapeutische Betreuung eines Patienten mit vermeintlichem oder tatsächlichem Kontaktekzem. PMID:26513064

  16. Schmerzen und Schmerztherapie in der Dermatologie.

    PubMed

    Beiteke, Ulrike; Bigge, Stefan; Reichenberger, Christina; Gralow, Ingrid

    2015-10-01

    Eine Prävalenzrate von 23 Millionen Deutschen mit chronischen Schmerzen ist anzunehmen. In einer aktuellen Erhebung waren 30 % der chronischen Schmerzpatienten mit ihrer Schmerztherapie nicht zufrieden. Des Weiteren leiden fünf Millionen Deutsche an neuropathischen Schmerzen, wovon 20 % nicht ausreichend therapiert sind. Schmerz ist auch ein Symptom vieler dermatologischer Krankheitsbilder. Die zumeist somatischen Schmerzen sind vielfach als milde Schmerzen einzustufen. Eine zunehmende Forschung zur Lebensqualität zeigt jedoch eine deutliche Beeinträchtigung der Lebensqualität durch moderate Schmerzen, u.a. bei Psoriasis vulgaris et arthropathica. Starke Schmerzen treten bei Herpes zoster, Ulcus cruris und Pyoderma gangraenosum auf. Als Grundlagen werden Schmerzklassifikation und im kurzen Exzerpt Schmerzleitung und -modulation dargestellt. Der Einsatz standardisierter Skalen zur Erhebung und Verlaufsbeobachtung der Schmerzstärke wird empfohlen, um Therapieoptimierungen zu gewährleisten und interdisziplinär auf gleicher Basis zu kommunizieren. Die Weiterbildung in der Dermatologie sieht den Erwerb von Kenntnissen, Erfahrungen und Fertigkeiten in der allgemeinen Schmerztherapie vor. Bezogen darauf werden grundlegende Behandlungskonzepte in Anlehnung an das erweiterte WHO-Schema, ein stufenweises Vorgehen sowie Kombinationstherapien dargestellt. Der Fokus dieser Arbeit liegt auf der Schmerztherapie o. g. konservativ zu behandelnder stark schmerzhafter Dermatosen. Neben gängigen Therapeutika und aktuellen Therapiestandards werden, soweit vorhanden, leitlinienbasiert spezifische Optionen erörtert. Der Wissensstand zum peri- und postoperativen Schmerzmanagement wird kurz umrissen. Dieser Artikel vermittelt: ? Grundlagen zur Klassifikation und Neurophysiologie von Schmerzen, ? Standards für die Schmerzdokumentation bei Kindern und Erwachsenen, ? allgemeine Standards für eine medikamentöse Schmerztherapie, ? aktuelle spezifische Therapieoptionen für Zosterneuralgie, Ulcus cruris, Pyoderma gangraenosum im Zusammenhang mit dem erweiterten WHO-Schema. PMID:26408456

  17. Astronomische Kupferstiche von Gottfried Teuber für Erhard Weigel

    NASA Astrophysics Data System (ADS)

    Herbst, Klaus-Dieter

    Zum Spektrum nichtverbaler Zeugnisse aus der Geschichte der Wissenschaften zählen auch die zahlreichen bildhaften Dokumente, auf denen die Objekte der wissenschaftlichen Untersuchung festgehalten sind, darunter auch die Kupferstiche (später Fotografien), die den astronomischen Büchern und Schriften beigegeben worden sind. Welcher wissenschaftshistorisch relevante Informationsgehalt ist nun solchen nichtverbalen Zeugnissen neben dem künstlerischen Aspekt der Illustration des Textes zuzubilligen? In Form einer Fallstudie soll im Vortrag ein bisher wenig beachteter Aspekt einer Antwort auf diese Frage angerissen werden. Im Rahmen dieser Fallstudie werden einige Kupferstiche aus dem Himmels=Zeiger`` von Erhard W eigel (1625-1699) vorgestellt, seit 1653 Professor für Mathematik an der Universität Jena und maßgeblicher Initiator der Kalenderreform in den protestantischen Ländern von 1699. Die in diesen Stichen enthaltenen Informationen können grob in drei Gruppen eingeteilt werden: A Aussagen zur Astronomie (dargestellte Himmelserscheinung), B Aussagen zur Drucktechnik (und künstlerischen Gestaltung), C Aussagen zur Biographie (des Herstellers bzw. Auftraggebers). Meines Erachtens ist der Aspekt C in der Historiographie bisher nicht erkannt worden. Hierauf soll mit einem Beispiel aufmerksam gemacht werden, wobei es um die Biographien von zwei Personen geht: die des Buchautors (Weigel) und die des Herstellers des Kupferstiches (Gottfried Teuber). Die Auswertung des Beispiels zeigt, daß durch Beachtung der sonst unauffällig erscheinenden Hersteller eines Kupferstiches Ansatzpunkte gefunden werden können, um Material für die noch unzureichend erforschte Beziehung zwischen den Gelehrten aus der ersten Reihe und deren Gehilfen aufzuspüren.

  18. A review of applications of satellite SAR, optical, altimetry and DEM data for surface water modelling, mapping and parameter estimation

    NASA Astrophysics Data System (ADS)

    Musa, Z. N.; Popescu, I.; Mynett, A.

    2015-09-01

    Hydrological data collection requires deployment of physical infrastructure like rain gauges, water level gauges, as well as use of expensive equipment like echo sounders. Many countries around the world have recorded a decrease in deployment of physical infrastructure for hydrological measurements; developing countries especially have less of this infrastructure and, where it exists, it is poorly maintained. Satellite remote sensing can bridge this gap, and has been applied by hydrologists over the years, with the earliest applications in water body and flood mapping. With the availability of more optical satellites with relatively low temporal resolutions globally, satellite data are commonly used for mapping of water bodies, testing of inundation models, precipitation monitoring, and mapping of flood extent. Use of satellite data to estimate hydrological parameters continues to increase due to use of better sensors, improvement in knowledge of and utilization of satellite data, and expansion of research topics. A review of applications of satellite remote sensing in surface water modelling, mapping and parameter estimation is presented, and its limitations for surface water applications are also discussed.

  19. A review of applications of satellite SAR, optical, altimetry and DEM data for surface water modelling, mapping and parameter estimation

    NASA Astrophysics Data System (ADS)

    Musa, Z. N.; Popescu, I.; Mynett, A.

    2015-05-01

    Hydrological data collection requires deployment of physical infrastructure like rain gauges, water level gauges, as well as use of expensive equipment like echo sounders. Many countries around the world have recorded a decrease in deployment of physical infrastructure for hydrological measurements; developing countries especially have less of this infrastructure and where they exist, they are poorly maintained. Satellite remote sensing can bridge this gap, and has been applied by hydrologists over the years, with the earliest applications in water body and flood mapping. With the availability of more optical satellites with relatively low temporal resolutions globally, satellite data is commonly used for: mapping of water bodies, testing of inundation models, precipitation monitoring, and mapping of flood extent. Use of satellite data to estimate hydrological parameters continues to increase due to use of better sensors, improvement in knowledge of/and utilization of satellite data, and expansion of research topics. A review of applications of satellite remote sensing in surface water modelling, mapping and estimation is presented, and its limitations for surface water applications are also discussed.

  20. Auf dem Weg zur digitalen Fakultät - moderne IT Infrastruktur am Beispiel des Physik-Departments der TU München

    NASA Astrophysics Data System (ADS)

    Homolka, Josef

    Der Geschäftsbetrieb einer Universität ist durch zunehmende Digitalisierung und Nutzung elektronischer Medien gekennzeichnet. Die Einführung immer leistungsfähigerer zentraler IT-Systeme führt zu einer komplexen Vielfalt heterogener Benutzer- und Administrationsschnittstellen. Zur Schaffung einer umfassenden benutzerfreundlichen und nahtlosen IT-Infrastruktur ist die Beteiligung aller organisatorischen Einheiten und Ebenen erforderlich. Am Physik-Departement der Technischen Universität München wurden unter Integration eigener Ressourcen mit zentralen Ressourcen, die im Rahmen des IntegraTUM Projektes entwickelt und bereitgestellt wurden, existierende Dienste weiterentwickelt und neue Angebote aufgebaut. Das System, bestehend aus den Komponenten Netzwerk, Arbeitsplatzrechner, Serverinfrastruktur, E-Mail-Service, WWWDienst, Datenhaltung und Software wurde für die Nutzerkreise Studenten und Mitarbeiter im Hinblick auf Anwenderfreundlichkeit und nahtlosen Zugriff optimiert.

  1. Handbibliothek am Lehrstuhl Broy 15. 9. 2000 Leihbedingungen: Grne Leihkarte dem Buch entnehmen, unterschreiben und im dafr

    E-print Network

    Cengarle, María Victoria

    . Proc. Summer School Marktoberdorf 1991, NATO ASI Series. Heidelberg: Springer. BERENDT, B. et al. (red Search. Wiley­Teubner Series in Computer Science, Stuttgart: Teubner. ANDREWS, G. R. (1991): Concurrent. BABER, R. L. (1991): Error­Free Software. Know­How and Know­Why of Programm Correctness. Wiley Series

  2. AK Hartmann, Thermodynamik und Statistische Physik 106 Hinweis: Musterlosungen zu Computeraufgaben aus dem Statistik Teil nun bei studip verfugbar.

    E-print Network

    Hartmann, Alexander K.

    S (Bereich I) bis ps (Bereich III) "im Kreis" 0: 0 = pB pS dp vI + pS pB dp vII + pA pS dp vII + ps pA dp vIII pB pS dp (vI - vII) = pS pA dp (vII - vIII) (14.10) geometrische Interpretation: Fl¨achen F1 = F2 Teilchenzahl l chemisches Potential µp l (T, p, cp 1, . . ., cp L) mit Konzentrationen (!) cp l = Np l /Np , Np

  3. Rapid delineation of alluvial fans using IfSAR-derived DEM for selected provinces in the Philippines

    NASA Astrophysics Data System (ADS)

    Ortiz, Iris Jill; Aquino, Dakila; Norini, Gianluca; Narod Eco, Rodrigo; Mahar Lagmay, Alfredo

    2015-04-01

    Alluvial fans are fan-shaped geomorphic features formed when sediments from a watershed are transported and deposited downstream via tributaries flowing out from the sudden break of a slope. Hazards usually associated with alluvial fans are flooding and debris flows. In this study, we used an Interferometric Synthetic Aperture Radar-derived digital elevation model of Pangasinan and Nueva Ecija Provinces in the Philippines to identify and delineate alluvial fans. Primary parameters considered include the geomorphic characteristics of the catchment area, stream network and slopes ranging from 0.11 to 8 degrees. Using this method, 12 alluvial fans were identified in Pangasinan and 16 in Nueva Ecija with areas ranging from 0.35 to 80 sq. km. The largest fan identified is the Mangatarem-Aguilar fan in Pangaisnan with a total area of 80.87 sq km while the Gabaldon fan in Nueva Ecija with total area of 48.11 sq km. We observed from the results that some alluvial fans have multiple feeder streams, and others have overlapping lateral extents with adjacent fans. These overlapping fans are called bajadas. In addition, the general location of fans and their apices in the two provinces appear to coincide with segments of the Philippines Fault System. There are about people 1.4 million living within these alluvial fans. Mapping and characterizing and identifying their associated hazards is crucial in the disaster preparedness efforts of the exposed population.

  4. reinfarction, there was a statistically significant benefit dem-onstrated for enoxaparin vs unfractionated heparin in the

    E-print Network

    Huey, Raymond B.

    to reperfusion in acute ST-segment elevation myocardial infarction: a meta- analysis of randomized trials. JAMA, or unfractionated heparin: the ASSENT-3 randomised trial in acute myocardial infarction. Lancet. 2001;358:605-613. 3-elevation myocardial infarction: results of the ENTIRE- Thrombolysis in Myocardial Infarction (TIMI) 23 Trial

  5. ?-TEMPy: Simultaneous Fitting of Components in 3D-EM Maps of Their Assembly Using a Genetic Algorithm

    PubMed Central

    Pandurangan, Arun Prasad; Vasishtan, Daven; Alber, Frank; Topf, Maya

    2015-01-01

    Summary We have developed a genetic algorithm for building macromolecular complexes using only a 3D-electron microscopy density map and the atomic structures of the relevant components. For efficient sampling the method uses map feature points calculated by vector quantization. The fitness function combines a mutual information score that quantifies the goodness of fit with a penalty score that helps to avoid clashes between components. Testing the method on ten assemblies (containing 3–8 protein components) and simulated density maps at 10, 15, and 20 Å resolution resulted in identification of the correct topology in 90%, 70%, and 60% of the cases, respectively. We further tested it on four assemblies with experimental maps at 7.2–23.5 Å resolution, showing the ability of the method to identify the correct topology in all cases. We have also demonstrated the importance of the map feature-point quality on assembly fitting in the lack of additional experimental information. PMID:26655474

  6. ?-TEMPy: Simultaneous Fitting of Components in 3D-EM Maps of Their Assembly Using a Genetic Algorithm.

    PubMed

    Pandurangan, Arun Prasad; Vasishtan, Daven; Alber, Frank; Topf, Maya

    2015-12-01

    We have developed a genetic algorithm for building macromolecular complexes using only a 3D-electron microscopy density map and the atomic structures of the relevant components. For efficient sampling the method uses map feature points calculated by vector quantization. The fitness function combines a mutual information score that quantifies the goodness of fit with a penalty score that helps to avoid clashes between components. Testing the method on ten assemblies (containing 3-8 protein components) and simulated density maps at 10, 15, and 20 Å resolution resulted in identification of the correct topology in 90%, 70%, and 60% of the cases, respectively. We further tested it on four assemblies with experimental maps at 7.2-23.5 Å resolution, showing the ability of the method to identify the correct topology in all cases. We have also demonstrated the importance of the map feature-point quality on assembly fitting in the lack of additional experimental information. PMID:26655474

  7. Meso-scale coupling of FEM/DEM for fluid-particle interactions S. Srivastava, K. Yazdchi and S. Luding*

    E-print Network

    Luding, Stefan

    's laws of motion and particle-particle/wall interactions are taken into account on the (smallest) scale with particle density in a given region. Two-way momentum exchange is implemented using semi-empirical drag laws et al. [11], Xu et al. [5] and Wu et al. [12]. In DPM, individual particles are tracked using Newton

  8. Forecasting of high frequency foreign currency data using artificial neural networks. A study of intraday USD/DEM exchange rates

    SciTech Connect

    Lodhia, P.; Antonious, A.; Esat, I.

    1996-12-31

    There has been much recent interest in the application of artificial intelligence systems to real world problems. Substantial interest has been shown in their application to investment markets. Artificial Neural Networks are the most common technique here. This paper is concerned with the use of ANNs in forecasting exchange rates. Much research has been carried out in currency markets. However, many of the studies use end of day or average quotes for currencies as a basis for prediction. A growing school of thought propose that markets are non-random in the short-term and can be shown to follow patterns. This short-term time span can be described as being a period when the markets are inefficient at price adjustments. The use of intraday data is an ideal testing ground for ANNs based research. This paper aims to study the intraday forecasting of the US Dollar/German Deutschmark and to address the question of whether ANNs can make acceptable predictions. The problems of forecasting in such a complex environment will be addressed.

  9. Use of Integrated MASTER Multispectral Imagery and LiDAR DEM for Active Fault Detection and Evaluation

    NASA Astrophysics Data System (ADS)

    Perez, F. G.; Bryant, W. A.; Treiman, J. A.; Real, C. R.; Hook, S.

    2011-12-01

    Displacement caused by surface fault rupture associated with large earthquakes not only disrupts infrastructure and damages natural and built environments, but also constitutes a life safety hazard. The California Geological Survey (CGS) has the authority and responsibility, under the Alquist-Priolo Earthquake Fault Zoning Act, to identify and map active faults in California for the purpose of surface rupture hazard identification and mitigation through regulatory zoning. Mapping and evaluation of active faults is generally accomplished through conventional aerial photo interpretation and field mapping, which rely on recognizing fault-related geomorphic features and juxtaposition of contrasting rocks, soil, and geologic structure. Faults covered by vegetation or concealed by young alluvium will most likely not be detected by this method. Furthermore, spatial accuracy of photo-interpreted fault traces is limited to the accuracy, scale, and method of transfer to conventional topographic base maps, which generally lack the spatial accuracy of geolocated imagery. The inherent limitations of conventional active fault mapping are expected to be overcome by using integrated MASTER and LiDAR data. MASTER is a multispectral imagery with 50 spectral bands ranging from visible to thermal region of the electromagnetic spectrum. LiDAR on the other hand is a laser-based technology with very high positional accuracy, sub-meter resolution and capability to filter out vegetation. MASTER and LiDAR are integrated via data transformation/fusion and the resulting fused imagery are utilized to interpret active faults through recognition of fault features associated with different distinctive properties related to geology, drainage, vegetation, hydrology, thermal, anthropogenic, and topography. The completeness and accuracy of the fault interpretation is gauged by overlaying it to a baseline data of previously mapped fault traces. The research study, supported by a NASA grant, evaluated a well-mapped, 26-km reach of the southern San Andreas Fault Zone in the Antelope Valley near Palmdale.

  10. 3D morphometry of valley networks on Mars from HRSC/MEX DEMs: Implications for climatic evolution through time

    NASA Astrophysics Data System (ADS)

    Ansan, V.; Mangold, N.

    2013-09-01

    valley networks have been identified mainly in the Noachian heavily cratered uplands. Eight dense branching valley networks were studied in Noachian terrains of Huygens, Newcomb and Kepler craters, south Tyrrhena Terra, and Thaumasia, in Hesperian terrains of Echus Plateau and west Eberswalde craters, and in Amazonian terrains of Alba Patera, using images and digital elevation models from the Mars Express High Resolution Stereo Camera to determine 2D and 3D morphometric parameters. Extracted geomorphic parameters show similar geometry to terrestrial valleys: drainage densities, organization from bifurcation ratios and lengths ratios, Hack exponent consistent with terrestrial values of ~0.6, and progressive deepening of valleys with increasing Strahler order. In addition, statistics on valley depths indicate a deeper incision of Noachian valleys compared to younger post-Noachian valleys (<25 m for Amazonian ones compared to >100 m for Noachian ones), showing a strong difference in fluvial erosion. These characteristics show that dense Martian valley networks formed by overland flows in relation to a global atmospheric water cycle in Noachian epoch and confirm that the later stages of activity may be related to shorter duration of activity, distinct climatic conditions, and/or regional processes, or conditions.

  11. Konsolidierte Fassung der Universitt Bayreuth: Der Text dieser Satzung ist nach dem aktuellen Stand sorgfltig erstellt; gleichwohl sind

    E-print Network

    Schmidt, Matthias

    ,,Biologische- und chemische Verfahrenstechnik", ,,Energie- und Umwelttechnik" und ,,Mechatronik und Automotive 130 Semesterwochenstunden (SWS). 2 In dieser Zahl ist die Abschlussarbeit, die in der Regel im

  12. CFD Analysis of the Effect of Temperature and Buoyancy Due to Concrete Building Structures Based from an Integrated DEM and

    E-print Network

    Alberta, University of

    on atmospheric temperature and the convection winds generated in the Aburra val- ley of Medelln, Colombia-Stokes Equations were solved for buoyant, turbulent flow of compressible fluid accounting for convection and heat valleys with no large wind speed due to the mountain protection. Applications include atmospheric heating

  13. Identification of Geomorphic Signatures of Neotectonic Activity Using dem in the Precambrian Terrain of Western Ghats, India

    NASA Astrophysics Data System (ADS)

    Jayappa, K. S.; Markose, V. J.; Nagaraju, M.

    2012-07-01

    To assess the relative tectonic activity classes, five geomorphic indices such as stream-gradient index (SL), drainage basin asymmetry (Af), hypsometric integral (Hi), valley floor width - valley height ratio (Vf) and drainage basin shape (Bs) of ninety-four sub-basins of Valapattanam river basin have been analysed by applying the standard formulae. Relative tectonic activity classes (Iat) obtained by the average (S/n) of different classes of geomorphic indices have been classified into three groups. Group I shows high tectonic activity with values of S/n < 2; group II shows moderate tectonic activity with S/n > 2 to < 2.5; and group III shows low tectonic activity with values of S/n ? 2.5. Field evidences such as deep valleys, sudden changes in the river course and waterfalls at fault planes clearly agree with the values and classes of tectonic geomorphic indices.

  14. Die allgemeine Terminologielehre--ein Grenzgebiet zwischen Sprachwissenschaft, Logik, Ontologie, Informatik und den Sachwissenschaften (The Theory of General Terminology--An Intersection of Linguistics, Logic, Ontology, Information Science, and the Technical Sciences)

    ERIC Educational Resources Information Center

    Wuster, Eugen

    1974-01-01

    Expanded version of a lecture held at the University of Vienna, May 25, 1972, and in shorter form at the Third International Congress for Applied Linguistics, Copenhagen, Denmark, August 22, 1972. (DD)

  15. H.C. Schumacher - Center of international communication in astronomy and mediator betwen Denmark an Germany. (German Title: H.C. Schumacher - Zentrum der internationalen Kommunikation in der Astronomie und Mittler zwischen Dänemark und Deutschland)

    NASA Astrophysics Data System (ADS)

    Hamel, Jürgen

    As the editor of the ``Astronomische Nachrichten'', H.C. Schumacher played an outstanding role among the astronomers of the first half of the 19th century. Altona, his place of activity, belonged to the kingdom of Denmark. Both the foundation of the ``Astronomische Nachrichten'' and its existence depended for several decades on the support by the Danish kings and high-ranking officials at the Copenhagen court. This paper analyses these questions on the basis of previously unused archival sources and discusses also Schumacher's life and his relations to the royal dynasty.

  16. Der Begriff des "Ki" und die japanische Padagogik: Uber Konflikte zwischen westlicher und japanischer Padagogik (The Concept of "Ki" and Japanese Pedagogy: On Conflicts between Western and Japanese Pedagogics).

    ERIC Educational Resources Information Center

    Fujikawa, Nobuo

    1997-01-01

    Sketches the characteristics of the Japanese educational tradition and analyzes conflicts between modern western pedagogies and traditional education. Argues that Japanese socialization processes stress a specifically Japanese construction of the "self" and of behavior. Concludes that Japanese educators should be more aware of this element in the…

  17. Der Briefwechsel zwischen Sidonie Na?dherny? und Albert Bloch : September 1947-September 1950 : mit einer Einfu?hrung in die Widmungsgedichte von Karl Kraus an Sidonie Na?dherny?

    E-print Network

    Champion, Elke Lorenz

    1998-01-01

    Die Aufgabe dieser Arbeit besteht darin, Sidonie Na?dherny? Einfluß auf das Werk von Karl Kraus, vor allem auf seine Lyrik, an Hand der Albert Bloch/Sidonie Na?dherny?-Korrespondenz auszuwerten. Neben den eigentlichen Briefen sind für diese...

  18. Diglossische Prozesse (Zwischen Deutsch und Spanisch) unter den Spanischen Emigranten der 2. Generation in Deutschland: Eine Soziolinguistische Studie (Diglossia Processes (Between German and Spanish) Among Second Generation Spanish Immigrants in Germany: A Sociolinguistic Study).

    ERIC Educational Resources Information Center

    Sanchez, Karin Vilar

    1998-01-01

    Presents a sociolinguistic study of second-generation Spanish immigrants in Germany. Specific focus is on "diglossia processes," or how Spanish and German are used for different sociolinguistic situations. (Author/VL)

  19. The controversy between Alexander Friedmann and Albert Einstein about the possibility of a non-static world (German Title: Die Kontroverse zwischen Alexander Friedmann und Albert Einstein um die Möglichkeit einer nichtstatischen Welt)

    NASA Astrophysics Data System (ADS)

    Singer, Georg

    Einstein's treatment of the cosmological problem as well as his unshakeable adherence to his own static solution of the complete field equations was throughout determined by Ernst Mach's idea of relativity of inertia. Friedmann, however, like Eddington, Weyl and others did not consider Mach's principle to be a part of general relativity, and so he regarded a time dependent developing spatial geometry as being consistent with world matter at relative rest. In his final statement to the controversy, Einstein acknowledged just formal correctness of Friedmann's results. Actually his criticism was not due ``to a miscalculation'', as he was ready to admit, but was owed to a fundamental fixed idea which continued to exist and which was the cause of his disavowal of physical significance of dynamical solutions.

  20. Hardware-Abbildung eines videobasierten Verfahrens zur echtzeitfähigen Auswertung von Winkelhistogrammen auf eine modulare Coprozessor-Architektur

    NASA Astrophysics Data System (ADS)

    Flatt, H.; Tarnowsky, A.; Blume, H.; Pirsch, P.

    2010-10-01

    Dieser Beitrag behandelt die Abbildung eines videobasierten Verfahrens zur echtzeitfähigen Auswertung von Winkelhistogrammen auf eine modulare Coprozessor-Architektur. Die Architektur besteht aus mehreren dedizierten Recheneinheiten zur parallelen Verarbeitung rechenintensiver Bildverarbeitungsverfahren und ist mit einem RISC-Prozessor verbunden. Eine konfigurierbare Architekturerweiterung um eine Recheneinheit zur Auswertung von Winkelhistogrammen von Objekten ermöglicht in Verbindung mit dem RISC eine echtzeitfähige Klassifikation. Je nach Konfiguration sind für die Architekturerweiterung auf einem Xilinx Virtex-5-FPGA zwischen 3300 und 12 000 Lookup-Tables erforderlich. Bei einer Taktfrequenz von 100 MHz können unabhängig von der Bildauflösung pro Einzelbild in einem 25-Hz-Videodatenstrom bis zu 100 Objekte der Größe 256×256 Pixel analysiert werden. This paper presents the mapping of a video-based approach for real-time evaluation of angular histograms on a modular coprocessor architecture. The architecture comprises several dedicated processing elements for parallel processing of computation-intensive image processing tasks and is coupled with a RISC processor. A configurable architecture extension, especially a processing element for evaluating angular histograms of objects in conjunction with a RISC processor, provides a real-time classification. Depending on the configuration of the architecture extension, 3 300 to 12 000 look-up tables are required for a Xilinx Virtex-5 FPGA implementation. Running at a clock frequency of 100 MHz and independently of the image resolution per frame, 100 objects of size 256×256 pixels are analyzed in a 25 Hz video stream by the architecture.

  1. IEEE JOURNALON OCEANICENGINEERING, VOL. OE-4, NO. 3, JULY 1979 113 [20] -, "Architektur aus dem Meer," Deursche Buuzeit, vol. 11,no.

    E-print Network

    Moura, José

    . Passive SystemsTheory With Narrow-Band and Linear Constraints:Part 111-Spatial/Temporal Diversity JOSE M based on synchronized measurements of the travel time delay are precluded by the incoherent phase model considered. The paper explores alternative methods that process the phase modula- tions induced onthe signal

  2. Channel planform geometry and slopes from freely available high-spatial resolution imagery and DEM fusion: Implications for channel width scalings, erosion proxies,

    E-print Network

    Bookhagen, Bodo

    fusion: Implications for channel width scalings, erosion proxies, and fluvial signatures in tectonically, lithologic variability, and a host of geomorphic processes (e.g. landsliding, out- burst floods, glacial

  3. Investigating a damaging buried sinkhole cluster in an urban area (Zaragoza city, NE Spain) integrating multiple techniques: Geomorphological surveys, DInSAR, DEMs, GPR, ERT, and trenching

    NASA Astrophysics Data System (ADS)

    Carbonel, Domingo; Rodríguez-Tribaldos, Verónica; Gutiérrez, Francisco; Galve, Jorge Pedro; Guerrero, Jesús; Zarroca, Mario; Roqué, Carles; Linares, Rogelio; McCalpin, James P.; Acosta, Enrique

    2015-01-01

    This contribution analyses a complex sinkhole cluster buried by urban elements in the mantled evaporite karst of Zaragoza city, NE Spain, where active subsidence has caused significant economic losses (~ 0.3 million Euro). The investigation, conducted after the development of the area, has involved the application of multiple surface and subsurface techniques. A detailed map of modern surface deformation indicates two active coalescing sinkholes, whereas the interpretation of old aerial photographs reveals the presence of two additional dormant sinkholes beneath human structures that might reactivate in the near future. DInSAR (Differential Interferometry Synthetic Aperture Radar) displacement data have limited spatial coverage mainly due to high subsidence rates and surface changes (re-pavement), and the Electrical Resistivity Tomography (ERT) and trenching investigations were severely restricted by the presence of urban elements. Nonetheless, the three techniques consistently indicate that the area affected by subsidence is larger than that defined by surface deformation features. The performance of the Ground Penetrating Radar (GPR) technique was adversely affected by the presence of highly conductive and massive anthropogenic deposits, but some profiles reveal that subsidence in the central sector of one of the sinkholes is mainly accommodated by sagging. The stratigraphic and structural relationships observed in a trench dug across the topographic margin of one of the sinkholes may be alternatively interpreted by three collapse events of around 0.6 m that occurred after 290 yr BP, or by progressive fault displacement combined with episodic anthropogenic excavation and fill. Average subsidence rates of > 6.6 mm/yr and 40 mm/yr have been calculated using stratigraphic markers dated by the radiocarbon method and historical information, respectively. This case study illustrates the need of conducting thorough investigations in sinkhole areas during the pre-planning stage including a geomorphic approach. A sound geomorphic model is essential for the proper design of the site investigation, the interpretation of the data and application of effective mitigation measures. Once sinkhole areas are developed, urban elements largely restrict the applicability and performance of multiple techniques, substantially decreasing the feasibility and benefit/effort ratio of the investigations.

  4. Nr. 276 / 2012 // 05. Oktober 2012 Die Teilnehmerinnen und Teilnehmer des Kick-off-Meetings zum EU-Projekt ,,HarWin" vor dem

    E-print Network

    Dettweiler, Michael

    ,,Harvesting solar energy with multifunctional glass-polymer windows" ­ kurz: ,,HarWin" ­ verweist auf dasWin" in das 7. Rahmenprogramm der Europäischen Union ein, die energieeffiziente Gebäude (,,Energy Efficient beeinträchtigt. Im Gegenteil, neuartige Polymer-Glas-Verbundstrukturen machen es möglich, die Energie des

  5. Modelling of the hydrological connectivity changes in the Minjiang Upstream after the Wenchuan earthquake using satellite remote sensing and DEM data

    NASA Astrophysics Data System (ADS)

    Zhang, H. Z.; Chi, T. H.; Fan, J. R.

    2015-02-01

    The 2008 Wenchuan earthquake-induced landslides destroyed larger areas of mountain vegetation and produced large volume of landslide-debris, which made the vegetation's hydrological adjusting function diminished and made the hydrological progresses in slopes changed, resulting in severe erosion and catastrophic debris flows for a rather long time. Since 2008, the landslide-damaged vegetation and its hydrological function have been recovering. In this paper, the Minjiang Upstream watersheds around Yingxiu Town were selected. First, the landslide-damaged vegetation was identified and monitored via multi-temporal (2001-2014) satellite images. Then, the slope materials stability was assessed through topographic analysis of the vegetation survival environments. Then, the hydrological connectivity index (HCI) was defined to describe the upstream sediment production and downstream transport pathway. Finally, results indicated that HCI decreased annually with the vegetation recovery after the obvious increases during the earthquakes. While, analysis of 2008-2013 debris flow events indicated that the areas, the vertical drop to river <1000 m and the horizontal distance to river <2500 m, have high HCI increases and are more susceptible for debris flow formation. Monitoring the landslide-damaged vegetation recovery processes can contribute to assess the hydrological connectivity changes and understand the debris flow formation.

  6. Baron von Zach's business relations with the Munich entrepreneur Joseph von Utzschneider (German Title: Geschäftsbeziehungen des Barons von Zach zu dem Münchner Unternehmer Joseph von Utzschneider)

    NASA Astrophysics Data System (ADS)

    Schneider, Ivo

    The relationship between the astronomer von Zach on the one side and the entrepreneur Joseph von Utzschneider and his partner Georg von Reichenbach on the other dates presumably from the year 1807 when Zach spent two months in Munich. Already in the same year Zach had ordered an instrument for himself and began to solicit business for the institute of Reichenbach, Utzschneider, and Liebherr, which was founded in 1804. One of the clients canvassed by Zach was the director of the observatory in Naples Zuccari. Zuccari had ordered the whole equipment for the new observatory from this institute in 1813. The instruments for Naples, which were completed in 1814, were sent accompanied by Reichenbach by land and sea to their destination where Reichenbach supervised their setup. At that time Reichenbach had separated from Utzschneider who kept the optical institute in Benediktbeuern with his new partner Joseph von Fraunhofer whereas Reichenbach became owner of the mathematical-mechanical institute in Munich. For personal and economical reasons Utzschneider began soon after to produce not only optical glass but also optical devices similar to those offered by Reichenbach. As soon as two institutes in Munich competed against each other on the market for sophisticated geodetical and astronomical instruments Zach sided with Utzschneider. Zach's main professional argument for this decision was that both competitors got the optical glass for their instruments from Utzschneider's optical institute in Benediktbeuern. This meant that Utzschneider had first choice and so the optical part of his instruments could be considered as better than that of Reichenbach`s instruments. Zach's role as an agent in Italy and France for the sale of products coming from Utzschneider's manufactories is highlighted by three of Zach's letters to Utzschneider from 1817 and 1818, two of which are reproduced here for the first time.

  7. GRANTOV SOUTZ GA UK 2014 -DOPLUJC INFORMACE grantov soutz se d Grantovm dem ve znn dostupnm na http://www.cuni.cz/UK-4347-

    E-print Network

    Cerveny, Vlastislav

    GRANTOVÁ SOUTZ GA UK 2014 - DOPLUJÍCÍ INFORMACE · grantová soutz se ídí Grantovým ádem ve znní na esení nejvýse tí projekt soucasn nebo mze být uveden nejvýse ve tech pihláskách projekt soucasn UK ve výsi 15% z celkových plánovaných pímých náklad, aplikace vypocítává rovnz automaticky

  8. GRANTOV SOUTZ GA UK 2016 -DOPLUJC INFORMACE grantov soutz se d Grantovm dem ve znn dostupnm na https://www.cuni.cz/UK-

    E-print Network

    Cerveny, Vlastislav

    GRANTOVÁ SOUTZ GA UK 2016 - DOPLUJÍCÍ INFORMACE grantová soutz se ídí Grantovým ádem ve znní GAUK pocítají automaticky a jsou zahrnuty do plánovaných osobních náklad; rezii, v pípad MFF UK ve GAUK je mozné; náklady na cestovné pro akademické a vdecké pracovníky je mozné plánovat pouze ve

  9. CityFIT Urban Guide: Modelling and Deploying indicators of Property Exposure to Flooding in Lagos using LIDAR DEM and DSM data 

    E-print Network

    Mosuro, Sulaiman

    2012-11-29

    The propagation of flood inundation in urban catchments is highly dependent on the surface topography, land cover and the representation of structure in elevation data used in modelling. Studies have shown that subtle variations in terrain have a...

  10. An Assessment of the Potential Use of SRTM DEMs in Terrain Analysis for the Efficient Mapping of Soils in the Dyrlands Region of Kazakhstan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The relationship between soil properties and hill slope position is well established. Potential variations in the amount of soil organic carbon (SOC) with topographic position must be considered in any mapping or inventory scheme. It is possible to establish statistical, geostatistical, and/ or ph...

  11. How to obtain constitutive relations about stress and density from DEM simulations Multi Scale Mechanics (MSM), University of Twente, Enschede, The Netherlands

    E-print Network

    Luding, Stefan

    pressures. 1 Introduction Fine, cohesive-frictional powders show peculiar flow behavior since several-frictional powders are the subject of this study. The behavior under isotropic compression is examined for different material properties involving, friction, rolling-resistance, and contact-adhesion. From a single simulation

  12. Impact of land use, soil and DEM databases on surface runoff assessment with GIS decision support tool: A study case on the Briançon vineyard catchment (Gard, France)

    NASA Astrophysics Data System (ADS)

    Regazzoni, C.; Payraudeau, S.

    2012-04-01

    Runoff and associated erosion represent a primary mode of mobilization and transfer of pesticides from agricultural lands to watercourses and groundwater. The pesticides toxicity is potentially higher at the headwater catchment scale. These catchments are usually ungauged and characterized by temporary streams. Several mitigation strategies and management practices are currently used to mitigate the pesticides mixtures in agro-ecosystems. Among those practices, Stormwater Wetlands (SW) could be implemented to store surface runoff and to mitigate pesticides loads. The implementation of New Potential Stormwater Wetlands (NPSW) requires a diagnosis of intermittent runoff at the headwater catchment scale. The main difficulty to perform this diagnosis at the headwater catchment scale is to spatially characterize with enough accuracy the landscape components. Indeed, fields and field margins enhance or decrease the runoff and determine the pathways of hortonian overland flow. Land use, soil and Digital Elevation Model databases are systematically used. The question of the respective weight of each of these databases on the uncertainty of the diagnostic results is rarely analyzed at the headwater catchment scale. Therefore, this work focused (i) on the uncertainties of each of these databases and their propagation on the hortonian overland flow modelling, (ii) the methods to improve the accuracy of each database, (iii) the propagation of the databases uncertainties on intermittent runoff modelling and (iv) the impact of modelling cell size on the diagnosis. The model developed was a raster approach of the SCS-CN method integrating re-infiltration processes. The uncertainty propagation was analyzed on the Briançon vineyard catchment (Gard, France, 1400 ha). Based on this study site, the results showed that the geographic and thematic accuracies of regional soil database (1:250 000) were insufficient to correctly simulate the hortonian overland flow. These results have to be weighted according to the soil heterogeneity. Conversely, the regional land use (1:50 000) provided an acceptable diagnostic when combining with accurate soil database (1:15 000). Moreover, the regional land use quality can be improved by integrating road and river networks usually available at the national scale. Finally, a 5 m modelling cell size appeared as an optimum to correctly describe the landscape components and to assess the hortonian overland flow. A wrong assessment of the hortonian overland flow leads to a misinterpretation of the results and affects effective decision-making, e.g. the number and the location of the NSPW. This uncertainty analysis and the improvement methods developed on this study site can be adapted on other headwater catchments characterized by intermittent surface runoff.

  13. Mit diesem Band 1 und dem sich anschlieenden Band 2 wird ein Kompendium fur einen kompletten Analysiszug in einem Bachelor-Studiengang Mathematik

    E-print Network

    Racke, Reinhard

    (Einf¨uhrung, 2 SWS) behandeln. Wir danken den Mitarbeitern Dipl.-Math. Mario Kaip, Dipl.-Math. Patrick Kurth, Dipl.-Math. Tobias Nau und Dipl.-Math. Michael Pokojovy f¨ur das Kor- rekturlesen und f Aufnahme in das Verlagsprogramm. Konstanz, M¨arz 2011 Robert Denk ­ Reinhard Racke #12;Inhaltsverzeichnis

  14. ‘A Wonderfull Monster Borne in Germany’: Hairy Girls in Medieval and Early Modern German Book, Court and Performance Culture*

    PubMed Central

    Katritzky, MA

    2014-01-01

    Human hirsuteness, or pathological hair growth, can be symptomatic of various conditions, including genetic mutation or inheritance, and some cancers and hormonal disturbances. Modern investigations into hirsuteness were initiated by nineteenth-century German physicians. Most early modern European cases of hypertrichosis (genetically determined all-over body and facial hair) involve German-speaking parentage or patronage, and are documented in German print culture. Through the Wild Man tradition, modern historians routinely link early modern reception of historical hypertrichosis cases to issues of ethnicity without, however, recognising early modern awareness of links between temporary hirsuteness and the pathological nexus of starvation and anorexia. Here, four cases of hirsute females are reconsidered with reference to this medical perspective, and to texts and images uncovered by my current research at the Herzog August Library and German archives. One concerns an Italian girl taken to Prague in 1355 by the Holy Roman Empress, Anna von Schweidnitz. Another focuses on Madeleine and Antonietta Gonzalez, daughters of the ‘Wild Man’ of Tenerife, documented at German courts in the 1580s. The third and fourth cases consider the medieval bearded Sankt Kümmernis (also known as St Wilgefortis or St Uncumber), and the seventeenth-century Bavarian fairground performer Barbara Urslerin. Krankhafter menschlicher Hirsutismus kann aufgrund unterschiedlicher Ursachen auftreten, zu denen u.a. genetische Veränderungen und Vererbung, verschiedene Krebserkrankungen und hormonelle Störungen gehören. Die moderne Hirsutismus-Forschung ist im 19. Jh. von deutschen Forschern initiiert worden. Die meisten europäischen frühneuzeitlichen Erscheinungen von Hypertrichose (dem genetisch bedingten Haarwuchs am gesamten Körper und im Gesicht) gehen auf deutschsprachige Eltern oder Förderer zurück und sind in Deutschland in den Druck gelangt. Bei Untersuchungen des Motivs des Wilden Mannes zieht die aktuelle geschichtswissenschaftliche Forschung in der Regel Verbindungslinien zwischen der frühneuzeitlichen Wahrnehmung von Hypertrichose-Fällen und Fragen der Ethnizität, ohne jedoch zu beachten, dass in der Frühen Neuzeit die Verbindung zwischen temporärem Hirsutismus und der krankhaften Verknüpfung von Unterernährung und Anorexie bekannt war. Im vorliegenden Beitrag werden vier Fälle von an Hirsutismus erkrankten Frauen neu analysiert, unter Einbezug dieser medizinischen Perspektive und unter Beachtung von Texten und Abbildungen, die meine jüngsten Forschungen in der Herzog August Bibliothek und an deutschen Archiven ans Licht gefördert haben. Die hier betrachteten Fälle betreffen ein italienisches Mädchen, das 1355 von Anna von Schweidnitz, Kaiserin des Hl. Römischen Reichs, nach Prag gebracht wurde; Madeleine und Antonietta Gonzalez, die Töchter des ‘Wilden Manns’ von Teneriffa, die in den 1580er Jahren an deutschen Höfen bezeugt sind; die bärtige Sankt Kümmernis (Wilgefortis), und die bayerische Jahrmarktkünstlerin Barbara Urslerin. PMID:25598545

  15. Sommersemester 2008 Universitat Heidelberg, Institut fur Theoretische Physik Theoretische Physik IV: Statistische Mechanik und Thermodynamik

    E-print Network

    Heermann, Dieter W.

    Energiefluktuationen sich verhalten wie E E 1 N (2 Punkte) Im thermodynamischen Limes verschwinden also die Fluktuationen (¨Aquivalenz zwischen mikrokanonischem und kanonischem Ensemble im thermodynamischen Limes)! (b

  16. Zrich, den 30. April 2002 Bildungsdirektion

    E-print Network

    Zürich, Universität

    Frühgeborenen: Ein Vergleich zwischen oraler und intravenöser Glukokortikoidgabe" Brauchlin Andreas Emil, von Schmerzpatienten: Eine prospektive Evaluation" Fischer Katja, von Triengen und Kulmerau LU in Triengen ,,Efficacy

  17. Modulhandbuch Bachelor-Studiengnge Informatik, Angewandte Informatik

    E-print Network

    Morik, Katharina

    . Insbesondere sollen hier Methoden erlernt werden, die durch formale Kontrolle die Zuverlässigkeit des), mind. ein Modul aus dem Bereich Mathematik für Informatiker bzw. dem Bereich Höhere Mathematik

  18. Schule in der Transformation--Transformation der Schule? Was man aus Gesprachen mit ehemaligen Schulern uber die Schule "zwischen zwei Diktaturen" erfahren kann (Schools in Transitions--Transformation of the School? What Can Be Learnt from Former Students Who Experienced Schooling under Two Dictatorial Regimes).

    ERIC Educational Resources Information Center

    Kluchert, Gerhard; Leschinsky, Achim

    1998-01-01

    Addresses interviews that focused on former students' educations under two dictatorial regimes. All the interviewees took their school-leaving examinations between 1951 and 1954. Explains that the interviews are evaluated according to the preconditions, limits, and mechanisms of the school's influence on children and adolescents. (CMK)

  19. FORS am Very Large Telescope der Europäischen Südsternwarte

    NASA Astrophysics Data System (ADS)

    1998-09-01

    Erstes wissenschaftliches Beobachtungsinstrument liefert eindrucksvolle Bilder Entsprechend dem straffen Zeitplan wird das ESO Very Large Teleskop Projekt (VLT-Projekt) auf dem Cerro Paranal in Nord-Chile verwirklicht: die volle Betriebsbereitschaft des ersten der vier 8,2m-Einzelteleskope wird Anfang des nächsten Jahres erreicht sein. Am 15. September 1998 wurde ein weiterer wichtiger Meilenstein erfolgreich, rechtzeitig und innerhalb des Kostenplans erreicht. Nur wenige Tage nach seiner Montage am ersten 8,2m-Einzelteleskop des VLT (UT1) konnte FORS1 ( FO cal R educer and S pectrograph) als erstes einer Gruppe leistungsfähiger und komplexer wissenschaftlicher Instrumente seine Beobachtungstätigkeit beginnen. Von Anfang an konnte es eine Reihe exzellenter astronomischer Bilder aufnehmen. Dieses bedeutende Ereignis eröffnet eine Fülle neuer Möglichkeiten für die europäische Astronomie. FORS - ein Höhepunkt an Komplexität FORS1 und das zukünftige Zwillingsinstrument (FORS2) sind das Ergebnis einer der eingehendsten und fortschrittlichsten technologischen Studien, die je für ein Instrument der bodengebundenen Astronomie durchgeführt wurden. Dieses einzigartige Instrument ist nun im Cassegrain-Fokus installiert und verschwindet beinahe, trotz seiner Dimensionen von 3 x 1.5m (Gewicht 2.3t), unterhalb des riesigen 53 m 2 großen Zerodurspiegels. Um die große Spiegelfläche und die hervorragende Bildqualität von UT1 optimal auszunützen, wurde FORS speziell so konstruiert, daß es die lichtschwächsten und entferntesten Objekte im Weltall untersuchen kann. Bald wird dieses komplexe VLT-Instrument den europäischen Astronomen erlauben, die derzeitigen Beobachtungshorizonte entscheidend zu erweitern. Die beiden FORS-Instrumente sind Vielzweck-Beobachtungsinstrumente, die in mehreren unterschiedlichen Beobachtungsarten eingesetzt werden können. Beispielsweise können Bilder mit zwei verschiedenen Abbildungsmaßstäben (Vergrößerungen) sowie Spektren mit unterschiedlicher spektraler Auflösung von einzelnen oder mehreren Objekten aufgenommen werden. Dabei erlaubt der schnelle Wechsel zwischen den unterschiedlichen Beobachtungsarten z.B. zunächst die Aufnahme und direkt anschließend die Spektroskopie weit entfernter Galaxien. Damit kann dann u.a. die stellare Zusammensetzung und die Entfernung bestimmt werden. Als eines der leistungsfähigsten astronomischen Instrumente seiner Art wird FORS1 ein wahres Arbeitspferd für die Untersuchung des fernen Universums darstellen. Der Bau von FORS Das FORS-Projekt wird unter ESO-Kontrakt von einem Konsortium dreier deutscher astronomischer Institute durchgeführt, der Landessternwarte Heidelberg und den Universitäts-Sternwarten von Göttingen and München. Bis zur Beendigung des Projekts werden die beteiligten Institute Arbeit im Umfang von ca. 180 Mann-Jahren eingebracht haben. Bei der Landessternwarte Heidelberg lag die Leitung des Projekts. Hier wurde außerdem das gesamte optische System konstruiert, die Beschaffung der Komponenten der abbildenden Optik und der Zusatzoptiken für Spektroskopie und Polarimetrie durchgeführt und die spezielle Computersoftware geschrieben, mit der die von FORS gelieferten Daten verarbeitet und ausgewertet werden. Darüber hinaus wurde in der Werkstatt der Sternwarte ein Teleskopsimulator gebaut, mit dem alle wesentlichen Funktionen von FORS in Europa getestet werden konnten, bevor das Instrument zum Paranal (Chile) transportiert wurde. An der Universitäts-Sternwarte Göttingen wurden Konstruktion, Herstellung und Zusammenbau der gesamten Mechanik von FORS durchgeführt. Der größte Teil der Präzisionsteile, insbesondere der Multispalteinheit, wurde in der feinmechanischen Werkstatt der Sternwarte hergestellt. Die Beschaffung der großen Instrumentengehäuse und Flansche, die Computeranalysen für mechanische und thermische Stabilität des empfindlichen Spektrographen und die Herstellung der speziellen Werkzeuge für Handhabung, Wartung und Justierung lag ebenso in der Verantwortung dieser Sternwarte wie die Tests der zahlreichen opto

  20. Intelligent, Energy Saving Power Supply and Control System of Hoisting Mine Machine with Compact and Hybrid Drive System / Inteligentne, Energooszcz?dne Uk?ady Zasilania I Sterowania Górniczych Maszyn Wyci?gowych Z Nap?dem Zintegrowanym Lub Hybrydowym

    NASA Astrophysics Data System (ADS)

    Szyma?ski, Zygmunt

    2015-03-01

    In the paper present's an analysis of suitableness an application of compact and hybrid drive system in hoisting machine. In the paper presented the review of constructional solutions of hoisting machines drive system, driving with AC and DC motor. In the paper presented conception of modern, energy sparing hoisting machine supply system, composed with compact motor, an supplied with transistor or thyristor converter supply system, and intelligent control system composed with multilevel microprocessor controller. In the paper present's also analysis of suitableness application an selected method of artificial intelligent in hoisting machine control system, automation system, and modern diagnostic system. In the paper one limited to analysis of: fuzzy logic method, genetic algorithms method, and modern neural net II and III generation. That method enables realization of complex control algorithms of hosting machine with insurance of energy sparing exploitation conditions, monitoring of exploitation parameters, and prediction diagnostic of hoisting machine technical state, minimization a number of failure states. In the paper present's a conception of control and diagnostic system of the hoisting machine based on fuzzy logic neural set control. In the chapter presented also a selected control algorithms and results of computer simulations realized for particular mathematical models of hoisting machine. Results of theoretical investigation were partly verified in laboratory and industrial experiments. Przedstawiono analiz? celowo?ci wprowadzania, nap?dów zintegrowanych oraz nap?dów hybrydowych, do uk?adów nap?dowych maszyn wyci?gowych. Zamieszczono przegl?d rozwi?za? konstrukcyjnych wybranych hybrydowych oraz zintegrowanych nap?dów maszyn wyci?gowych z silnikami DC i AC. Opisano koncepcj? nowoczesnego, energooszcz?dnego uk?adu zasilania górniczych maszyny wyci?gowej, z?o?onego z silnika zintegrowanego, (tranzystorowego lub tyrystorowego) zasilacza przekszta?tnikowego, oraz inteligentnego obwodu sterowania zbudowanego na wielopoziomowych sterownikach mikroprocesorowych. Przedstawiono analiz? mo?liwo?ci zastosowania wybranych metod sztucznej inteligencji w uk?adach sterowania, automatyki oraz diagnostyki maszyn wyci?gowych. W referacie ograniczono si? do analizy metod sterowania rozmytego, metod algorytmów genetycznych oraz nowoczesnych sieci neuronowych II oraz III generacji. Metody te zapewniaj? realizacj? z?o?onych algorytmów sterowania maszyn? wyci?gow? z zapewnieniem energooszcz?dnych warunków eksploatacyjnych, monitoringu parametrów eksploatacyjnych oraz predykcyjn? diagnostyk? stanu technicznego maszyny wyci?gowej, minimalizuj?c? liczb? stanów awaryjnych. Przedstawiono koncepcj? uk?adu sterowania i diagnostyki maszyny bazuj?cej na metodzie: fuzzy-logic neuro set control system (sterowanie rozmyte w sieciach neuronowych). Przedstawiono wybrane algorytmy sterowania oraz wyniki analiz komputerowych wybranych modeli matematycznych maszyny wyci?gowej. Wyniki rozwa?a? teoretycznych zosta?y cz??ciowo sprawdzone w warunkach laboratoryjnych oraz przemys?owych.

  1. Partielle Geschlechtertrennung--Enttauschte Hoffnungen? Monoedukative Lernumgebungen zum Chancenausgleich im Unterricht auf dem Prufstand (Partial Separation of the Sexes--Disappointed Hopes? An Assessment of Non-Educative Learning Environments for Equalizing Educational Opportunities).

    ERIC Educational Resources Information Center

    Ludwig, Peter H.

    2003-01-01

    Argues that the thesis of discrimination against girls in coeducation schools has been replaced by a belief that, during certain phases or in specific subjects, abandonment of coeducation would promote equal opportunities. Questions whether classic or recent surveys provide empirical evidence for this moderate skeptical attitude towards…

  2. Vor 100 Jahren ffnete in Berlin-Dahlem das Kaiser-Wilhelm-Institut fr Chemie seine Pforten. Schon drei Jahre spter konnte es mit dem ersten Nobelpreistrger aufwarten: Richard Willsttter

    E-print Network

    Falge, Eva

    gewinnen können. Willstätter war ein Schüler des berühmten Adolf von Baeyer, hatte in München über die zuversichtlich, daß aus ihm eine ununterbrochene Schar von blühenden, hoffnungsvollen Kindern in Gestalt von glän Institut für Chemie vom Hofarchitekten Ernst von Ihne im Stil der Dahlemer Villen entwor- fen und in einer

  3. Aktuelle Jubilen aus dem Bereich der Chemie an der Friedrich-Schiller-Universitt Jena sind Anlass fr die in loser Folge erscheinenden ,,Chemiehistorischen Notizen". Sie wenden sich vor allem an

    E-print Network

    Rossak, Wilhelm R.

    in Princeton (USA); 1921 Nobelpreis f. Physik (Quantentheorie). 7 FRITZ HABER (1868 ­ 1934); Prof. f nur an die Arbeiten von M. PLANCK 5 , A. EINSTEIN 6 , F. HABER 7 erinnert - lernte er nicht nur das

  4. Beginning Awareness-Rigidity-Flexibility: A Longitudinal Analysis of Sex-Role Stereotyping in 4- to 10-Year-Old Children (Langsschnittliche Analyse von Entwicklungsmerkmalen der Geschlechtstypisierung im Kindersalter. Arbeiten aud dem Forschungsprojekt Nr. 5. 1989/1).

    ERIC Educational Resources Information Center

    Trautner, Hanns Martin; And Others

    A three-phase developmental model of sex-role stereotyping that viewed the acquisition of sex-role stereotypes as part of the broader process of the development of social understanding was proposed. Phases in the model included: (1) beginning awareness of sex-role differentiation; (2) rigid sex-role stereotyping; and (3) flexible sex-role…

  5. WEST COAST DIGITAL ELEVATION MODELSCoastal Models Supporting our Nation's Needs through Science and Technology All of the coastal digital elevation models (DEMs) in this presentation were created by scientists

    E-print Network

    States contains some of the largest metropolitan cities in the country including Los Angeles, San, storms, and landslides in the area can trigger waves that propagate along the coast to highly populated

  6. Hydro-geophysical interpretation of fractured and karstified limestones reservoirs: A case study from Amdoun region (NW Tunisia) using electrical resistivity tomography, digital elevation model (DEM) and hydro-geochemical approaches

    NASA Astrophysics Data System (ADS)

    Redhaounia, Belgacem; Aktarakçi, Hasan; Ilondo, Batobo Ountsche; Gabtni, Hakim; Khomsi, Sami; Bédir, Mourad

    2015-12-01

    Groundwater from fractures and karst in limestone rocks is an important source of drinking water in the semi-arid climatic environment of North-Western Tunisia where cool and rainy seasons alternate with hot dry seasons. Due to varying climatic conditions and anthropogenic interventions the fractured limestone aquifer systems (Abiod and Boudabbous/El Gueria Formations) tend to be complex. The lack of data on the fractured and karstified aquifers in Amdoun region (NW Tunisia) to establish the hydrogeological potential between different rock formations of Upper Cretaceous and Lower Eocene has often discouraged researchers from attempting to model such aquifers. On the SE flank of the Jebel Sabbah anticline, Electrical Resistivity Tomography Data were collected along three different lines of 315 m of length each. The expected vertical penetration depth was 60 m. This hydro-geophysical investigation consisting of geological, structural, and geo-morphological studies, has demonstrated that groundwater in the carbonate rocks, in Amdoun area, occur in fracture zones and weathered parts of the rocks in the karst aquifers. The hydrochemical data (major ion geochemistry) indicate that these groundwaters are characterized by the dominance a Ca-Mg-HCO3 water type. Geochemical pattern is mainly controlled by the dissolution of carbonate minerals. Generally, TDS increases from the Amdoun Monts towards the discharge area (53 < TDS<332 mg l-1). These results are assessed using numerous geophysical data such as ERT imaging and geological knowledge. Finally, we show how these results could be used to improve the management of karst groundwater resources in Amdoun (NW Tunisia) complex terrain.

  7. Mitarbeiterqualifizierung in der Montage

    NASA Astrophysics Data System (ADS)

    Buck, Hartmut

    Ein langfristiger Wettbewerbsvorteil kann nicht nur durch die Neuorganisation der Strukturen and Prozesse in der Montage erlangt werden, sondern auch durch die systematische Entwicklung der Mitarbeiterqualifikationen. Durch qualifizierte und engagierte Mitarbeiter entstehen Leistungsvorteile, die durch Wettbewerber schwer zu imitieren sind. Eine darauf ausgerichtete Unternehmensentwicklung beinhaltet in diesem Zusammenhang immer auch eine Personal- and Qualifikationsentwicklung.

  8. Curriculum Vitae Name / Titel Prof. Dr. Ulrich Bucher

    E-print Network

    Stroetmann, Karl

    . Marketing und Dienstleistungsmanagement Qualifikationen Akademischer Werdegang 1992-1997: Studium der-2004: Promotion (berufsbegleitend): Die sozialen Folgen des Internets im Zusammenhang mit den Internet/2002-12/2009: Leiter Marketing 07/2001-08/2002: Marketing Professional Infomatec Media AG 04/2001-06/2001: Leiter

  9. Kommunikation mit Mitarbeitern

    NASA Astrophysics Data System (ADS)

    Spychala, Anne; Fleischmann, Jürgen

    Kommunikation ist der Austausch von Nachrichten und Informationen zwischen Mitarbeitern eines Unternehmens (O'Hair et al. 1997). Dieser Austausch kann persönlich, aber z.B. auch per Telefon, E-Mail oder durch Computersysteme erfolgen. In diesem Kapitel betrachten wir die persönliche Kommunikation zwischen Vorgesetzten und Mitarbeitern. Zur persönlichen Kommunikation mit Mitarbeitern zählen sowohl formelle Gespräche mit Mitarbeitern als auch eher informelle Gespräche zwischen Tür und Angel. Die Gespräche können dabei mit einzelnen Mitarbeitern (z.B. jährliches Mitarbeitergespräch) oder mit Gruppen von Mitarbeitern (z.B. regelmäßige Projekt- oder Teambesprechungen) stattfinden.

  10. ERSTES BUCH. DIE FREIE. ERSTES KAPITEL.

    E-print Network

    Prodinger, Helmut

    Mittelding von Seegebiet und Uferland, eine Art Grenzstrich zwischen Wasser und Wiese, der, den größten Teil Wassergevögel Zuflucht zugleich und Weide bot. Dies Land war schon geraume Zeit im Besitz der Ala- mannen. Auf

  11. Universitt Ulm | 89069 Ulm | Germany Fakultt fr Ingenieurwissenschaften

    E-print Network

    Ulm, Universität

    .3 Allgemeine Anforderungen . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 HTML5 vs. Flash 7 3.1 Vergleich zwischen HTML5 und Flash . . . . . . . . . . . . . . . . . . . . . . 8 3.1.1 Benutzersicht . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2 Adobe Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4 HTML5

  12. Temporal Predictions with Bayesian Compositional Hierarchies

    E-print Network

    Hamburg,.Universität

    Temporal Predictions with Bayesian Compositional Hierarchies Bernd Neumann Technical Note: FBI innerhalb von objektzentrierten Aggregaten in uneingeschränkter Form repräsentiert, zwischen Aggregaten providing efficient inference procedures. New closed-form solutions are presented for inferences

  13. Eruptive Ereignisse als Kennzeichen später Sternentwicklung

    NASA Astrophysics Data System (ADS)

    Seitter, W. C.

    Die Autorin hat mit V605 Aql ein vermutliches Bindeglied zwischen planetarischen Nebeln und Novae gefunden. Sie sucht nun nach beobachtbaren Gemeinsamkeiten der beiden Objektklassen und weiterer eruptiver Sterne.

  14. Assessing the quality of Digital Elevation Models obtained from mini-Unmanned Aerial Vehicles for overland flow modelling in urban areas

    NASA Astrophysics Data System (ADS)

    Leitão, J. P.; Moy de Vitry, M.; Scheidegger, A.; Rieckermann, J.

    2015-06-01

    Precise and detailed Digital Elevation Models (DEMs) are essential to accurately predict overland flow in urban areas. Unfortunately, traditional sources of DEM remain a bottleneck for detailed and reliable overland flow models, because the resulting DEMs are too coarse to provide DEMs of sufficient detail to inform urban overland flows. Interestingly, technological developments of Unmanned Aerial Vehicles (UAVs) suggest that they have matured enough to be a competitive alternative to satellites or airplanes. However, this has not been tested so far. In this this study we therefore evaluated whether DEMs generated from UAV imagery are suitable for urban drainage overland flow modelling. Specifically, fourteen UAV flights were conducted to assess the influence of four different flight parameters on the quality of generated DEMs: (i) flight altitude, (ii) image overlapping, (iii) camera pitch and (iv) weather conditions. In addition, we compared the best quality UAV DEM to a conventional Light Detection and Ranging (LiDAR)-based DEM. To evaluate both the quality of the UAV DEMs and the comparison to LiDAR-based DEMs, we performed regression analysis on several qualitative and quantitative metrics, such as elevation accuracy, quality of object representation (e.g., buildings, walls and trees) in the DEM, which were specifically tailored to assess overland flow modelling performance, using the flight parameters as explanatory variables. Our results suggested that, first, as expected, flight altitude influenced the DEM quality most, where lower flights produce better DEMs; in a similar fashion, overcast weather conditions are preferable, but weather conditions and other factors influence DEM quality much less. Second, we found that for urban overland flow modelling, the UAV DEMs performed competitively in comparison to a traditional LiDAR-based DEM. An important advantage of using UAVs to generate DEMs in urban areas is their flexibility that enables more frequent, local and affordable elevation data updates, allowing, for example, to capture different tree foliage conditions.

  15. Cosmological applications of gravitational lensing

    NASA Astrophysics Data System (ADS)

    Schmidt, Robert W.

    2000-06-01

    In this thesis we use the gravitational lensing effect as a tool to tackle two rather different cosmological topics: the nature of the dark matter in galaxy halos, and the rotation of the universe. Firstly, we study the microlensing effect in the gravitational lens systems Q0957+561 and Q2237+0305. In these systems the light from the quasar shines directly through the lensing galaxy. Due to the relative motion of the quasar, the lensing galaxy, and the observer compact objects in the galaxy or galaxy halo cause brightness fluctuations of the light from the background quasar. We compare light curve data from a monitoring program of the double quasar Q0957+561 at the 3.5m telescope at Apache Point Observatory from 1995 to 1998 (Colley, Kundic & Turner 2000) with numerical simulations to test whether the halo of the lensing galaxy consists of massive compact objects (MACHOs). This test was first proposed by Gott (1981). We can exclude MACHO masses from 10^-6 M_sun up to 10^-2 M_sun for quasar sizes of less than 3x10^14 h_60^-0.5 cm if the MACHOs make up at least 50% of the dark halo. Secondly, we present new light curve data for the gravitationally lensed quadruple quasar Q2237+0305 taken at the 3.5m telescope at Apache Point Observatory from June 1995 to January 1998. Although the images were taken under variable, often poor seeing conditions and with coarse pixel sampling, photometry is possible for the two brighter quasar images A and B with the help from HST observations. We find independent evidence for a brightness peak in image A of 0.4 to 0.5 mag with a duration of at least 100 days, which indicates that microlensing has taken place in the lensing galaxy. Finally, we use the weak gravitational lensing effect to put limits on a class of Goedel-type rotating cosmologies described by Korotky & Obukhov (1996). In weak lensing studies the shapes of thousands of background galaxies are measured and averaged to reveal coherent gravitational distortions of the galaxy shapes by foreground matter distributions, or by the large-scale structure of space-time itself. We calculate the predicted shear as a function of redshift in Goedel-type rotating cosmologies and compare this to the upper limit on cosmic shear gamma_limit of approximately 0.04 from weak lensing studies. We find that Goedel-type models cannot have larger rotations omega than H_0=6.1x10^-11 h_60/year if this shear limit is valid for the whole sky. In dieser Arbeit benutze ich den Gravitationslinseneffekt als ein Werkzeug, um zwei recht unterschiedliche kosmologische Fragestellungen zu bearbeiten: die Natur der dunklen Materie in Galaxienhalos und die Rotation des Universums. Zuerst untersuche ich den Mikrolinseneffekt in den Gravitationlinsensystemen Q0957+561 und Q2237+0305. In diesen Systemen scheint das Licht eines Quasars durch die Linsengalaxie hindurch. Aufgrund der Relativbewegung zwischen Quasar, Linsengalaxie und Beobachter verursachen kompakte Objekte innerhalb der Galaxie oder dem Galaxienhalo Helligkeitsfluktuationen des Hintergrundquasars. Ich vergleiche die am 3.5m Teleskop des Apache Point Observatory zwischen 1995 und 1998 gewonnene Lichtkurve des Doppelquasars Q0957+561 (Colley, Kundic & Turner 2000) mit numerischen Simulationen, um zu untersuchen, ob der Halo der Linsengalaxie aus massiven kompakten Objekten (MACHOs) besteht. Dieser Test wurde zuerst von Gott (1981) vorgeschlagen. Ich kann MACHO-Massen von 10^-6 M_sun bis zu 10^-2 M_sun ausschliessen, sofern der Quasar kleiner ist als 3x10^14 h_60^-0.5 cm und MACHOs mehr als 50% des dunklen Halos ausmachen. Im zweiten Teil der Arbeit stelle ich neue Beobachtungsdaten fuer den Vierfachquasar Q2237+0305 vor, die am 3.5m Teleskop des Apache Point Observatory zwischen Juni 1995 und Januar 1998 gewonnen wurden. Obwohl die Daten bei veraenderlichen, oft schlechten Seeing Bedingungen und grober Pixelaufloesung aufgenommen wurden, ist die Photometrie der beiden helleren Quasarbilder A und B mit Hilfe von HST-Beobachtungen moeglich. Ich finde ein Helligkeitsmaximum in Bild A mit einer Amplitu

  16. 11 I F" d I11 Der regiona e or erpre s .Nordwest-Award" der Bre-

    E-print Network

    an der Carl von Ossietzky Universität 01- denburg und der Rijksuniver- siteit Groningen beruht. Mit dem junge Menschen auch aus anderen Teilen Deutschlands oder aus dem Ausland, angelockt, wodurch die Lücke

  17. INFRASTRUCTURE FOR ALTERNATIVE FUELS

    E-print Network

    California at Davis, University of

    planning for chargers and EVs · Outcomes · Tools for GIS Professionals · Market tool · Workplace charging -Dem US Census LODES Street Network Tele Atlas Block Group Statistics Map Individual Socio -Dem UC

  18. PREPARING ARTICLES FOR THE IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS 1 Terrain Synthesis from Digital Elevation Models

    E-print Network

    Turk, Greg

    , such as a terrain with the geological features of the Grand Canyon. Fig. 2(a) and 2(b) show examples of fractal terrain using DEM of Flathead National Forest Mountain Range (top image) and DEM of the Grand Canyon

  19. Resolution of grain scale interactions using the Discrete Element Method

    E-print Network

    Johnson, Scott M. (Scott Matthew), 1978-

    2006-01-01

    Granular materials are an integral part of many engineering systems. Currently, a popular tool for numerically investigating granular systems is the Discrete Element Method (DEM). Nearly all implementations of the DEM, ...

  20. Using Digital Elevation Data for Applications in Floodplain Mapping

    E-print Network

    Kastens, Jude Heathcliff

    2007-11-14

    Elevation Data for Applications in Floodplain Mapping Jude H. Kastens (jkastens@ku.edu) Background Examples: Sink Filling Digital Elevation Model (DEM) road cut Background Examples: Sink Filling DEM with sinks filled (depressionless DEM) road cut 30-m DEM...-digit hydrologic unit code (HUC8) boundaries are shown in red. These quasi- watersheds depict local catchments. IA NE MO KS Background Examples: Big River Background Examples: Big River The 16-m floodplain is shown in light blue. This particular...

  1. Scaling Terrain Attributes By Fractal Methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Terrain attributes derived from grid digital elevation models (DEMs) are commonly used in distributed hydrologic models. However, many attribute estimations are biased by DEM grid cell size. For example, land surface slopes estimated from 30-m DEMs are, on average, less than slopes estimated from ...

  2. A geomorphology based approach for digital elevation model fusion - case study in Danang City, Vietnam

    NASA Astrophysics Data System (ADS)

    Tran, T. A.; Raghavan, V.; Masumoto, S.; Vinayaraj, P.; Yonezawa, G.

    2014-04-01

    Global Digital Elevation Model (DEM) is considered as vital spatial information and finds wide use in several applications. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global DEM (GDEM) and Shuttle Radar Topographic Mission (SRTM) DEM offer almost global coverage and provide elevation data for geospatial analysis. However, GDEM and SRTM still contain some height errors that affect the quality of elevation data significantly. This study aims to examine methods to improve the resolution as well as accuracy of available free DEMs by data fusion technique and evaluating the results with high quality reference DEM. The DEM fusion method is based on the accuracy assessment of each global DEM and geomorphological characteristics of the study area. Land cover units were also considered to correct the elevation of GDEM and SRTM with respect to the bare earth surface. Weighted averaging method was used to fuse the input DEMs based on landform classification map. According to the landform types, the different weights were used for GDEM and SRTM. Finally, a denoising algorithm (Sun et al., 2007) was applied to filter the output fused DEM. This fused DEM shows excellent correlation to the reference DEM having correlation coefficient R2 = 0.9986 and the accuracy was also improved from Root Mean Square Error (RMSE) 14.9 m in GDEM and 14.8 m in SRTM into 11.6 m in fused DEM.

  3. EVALUATING SOIL EROSION PARAMETER ESTIMATES FROM DIFFERENT DATA SOURCES

    EPA Science Inventory

    Topographic factors and soil loss estimates that were derived from thee data sources (STATSGO, 30-m DEM, and 3-arc second DEM) were compared. Slope magnitudes derived from the three data sources were consistently different. Slopes from the DEMs tended to provide a flattened sur...

  4. Doktor Johannes Häringshauser - Was seine Bücher über ihn erzählen.

    NASA Astrophysics Data System (ADS)

    Feola, Vittoria

    2009-06-01

    Die Bibliothek des Dr. Johannes Häringshauser (1603-1642) weist ihren Besitzer als Arzt und Gelehrten mit großem geistigen Horizont aus. Hervorzuheben ist sein Interesse für Astronomie und Astrologie. Neben Werken, die unmittelbar mit seinen Studien in Wien und Padua und den Erfordernissen eines Arztes in Zusammenhang zu bringen sind (Klassiker der Heilkunde genauso wie aktuelle medizinische Publikationen), wird in seiner Büchersammlung eine reiche Palette an Themen abgedeckt: Theologie, Philosophie, Philologie, Politik, Geschichte und Länderkunde.

  5. Kapitel V Algorithmen und Datenstrukturen 1. Analyse von Algorithmen

    E-print Network

    Schmid, Stefan

    ¨ange der Ausgabe ist etwa log2 n! = (n log n) Bits. ADS-EI 1.0 LL(k)-Grammatiken 280/342 Ernst W. Mayr #12 Zusammenhang mit Komplexit¨atsabsch¨atzungen log(0) := 0 . ADS-EI 1.0 LL(k)-Grammatiken 281/342 Ernst W. Mayr arithmetische Operationen wie n, sin n,. . . ADS-EI 1.1 Referenzmaschine 282/342 Ernst W. Mayr #12;Schreibkopf

  6. P R E S S E I N F O R M A T I O N Leipziger Mathematiker fr hervorragende Dissertation ausgezeichnet

    E-print Network

    -Planck-Institut für Mathematik in den Naturwissenschaften wurde für seine Dissertation mit der Otto-Hahn-Medaille der Leistungen, die sie in der Regel in Zusammenhang mit ihrer Doktorarbeit erbracht haben, mit der Otto-Hahn-Preis für sein Physik-Diplom und mit der Otto-Volk-Medaille für sein Diplom im Fach Mathematik ausgezeichnet

  7. Application of an enhanced discrete element method to oil and gas drilling processes

    NASA Astrophysics Data System (ADS)

    Ubach, Pere Andreu; Arrufat, Ferran; Ring, Lev; Gandikota, Raju; Zárate, Francisco; Oñate, Eugenio

    2015-10-01

    The authors present results on the use of the discrete element method (DEM) for the simulation of drilling processes typical in the oil and gas exploration industry. The numerical method uses advanced DEM techniques using a local definition of the DEM parameters and combined FEM-DEM procedures. This paper presents a step-by-step procedure to build a DEM model for analysis of the soil region coupled to a FEM model for discretizing the drilling tool that reproduces the drilling mechanics of a particular drill bit. A parametric study has been performed to determine the model parameters in order to maintain accurate solutions with reduced computational cost.

  8. A continuative variable resolution digital elevation model for ground-based photogrammetry

    NASA Astrophysics Data System (ADS)

    Liu, Zhaoqin; Peng, Man; Di, Kaichang

    2014-01-01

    A new digital elevation model (DEM) is presented for accurate surface representation in photogrammetric processing of stereo ground-based imagery. This model is named the continuative variable resolution DEM (cvrDEM). In contrast to traditional grid-based DEMs that have only one fixed resolution, this new model can provide resolutions that vary depending on the range represented in the ground-based imagery. Functions for deriving radial and angular resolutions from the cvrDEM have been derived, and a corresponding storage structure for the polar coordinates has been developed. Experimental results using publically available NASA Mars Exploration Rover 2003 imagery demonstrate the effectiveness of the cvrDEM model: It can significantly reduce storage space while fully maintaining the most useful level of mapping accuracy relevant to the range from the imaging station. A terrestrial laser scanning data set was also used to validate the effectiveness of the cvrDEM.

  9. Generation of a new Greenland Ice Sheet Digital Elevation Model

    NASA Astrophysics Data System (ADS)

    Nagarajan, S.; Csatho, B. M.; Schenk, A. F.; Babonis, G. S.; Scambos, T. A.; Haran, T. M.; Kjaer, K. H.; Korsgaard, N. J.

    2011-12-01

    Currently available Digital Elevation Models(DEMs) of the Greenland Ice Sheet (GrIS) were originally derived from radar altimetry data, e.g. Bamber (Bamber et al., 2001) and later improved by photoclinometry to fill the regions between orbits (Scambos and Haran, 2002). The elevation error of these DEMs is a few meters in the higher part (above 2000 m) of the ice sheet, but it can be as much as 50-100 meters in marginal regions. The relatively low resolution and accuracy poses a problem, especially for ice sheet modeling. Although accurate elevation data have been collected by airborne and spaceborne laser altimetry (airborne: Airborne Topographic Mapper (ATM) (1993-present), Laser Vegetation Imaging Sensor(LVIS) (2007,2009 and 2011); spaceborne: Ice, Cloud, and land Elevation Satellite (ICESat) (2003-2009)) and DEMs have been derived from stereo satellite imagery (e.g., SPOT (40 m), ASTER (15 m)), a high resolution, consistent DEM of GrIS is not yet available. This is due to various problems, such as different error sources in the data and different dates of data acquisition. In order to overcome these difficulties, we generated a multi-resolution DEM of GrIS, reflecting June 2008 conditions, by fusing a photoclinometry DEM, SPOT and ASTER DEMs as well as elevations from ICESat, ATM and LVIS laser altimetry. The new multi-resolution DEM has a resolution of 40 m x 40 m in the marginal ice sheet regions and 250 m elsewhere. The ice sheet margin is mapped from SPOT and Landsat imagery and SPOT DEMs are used to cover the complex topography of ice sheet marginal regions. The accuracy of SPOT DEMs is approximately ± 6 m except in the areas covered by clouds regions, where the SPOT elevations were replaced by ASTER DEMs. The ASTER DEMs were checked and improved by the DEM derived from aerial photography from the 1980s. A new photoclinometry DEM, derived from Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) imagery provide a 250-meter resolution base topography at the higher elevations. ICESat and ATM and LVIS laser altimetry observations are used to improve the absolute elevation accuracy by computing the difference between the base DEM and point elevations, followed by 'distributing' the differences over the DEM using kriging interpolation. Adding these interpolated differences to the elevations at the grid posts results in an updated DEM. Finally, all elevations were corrected using elevation changes determined by SERAC (Surface Elevation Reconstruction And Change detection), to achieve a common reference date. Airborne laser altimetry elevations are used to evaluate the accuracy of the new GrIS DEM.

  10. Benchmark Test of Differential Emission Measure Codes and Multi-thermal Energies in Solar Active Regions

    NASA Astrophysics Data System (ADS)

    Aschwanden, Markus J.; Boerner, Paul; Caspi, Amir; McTiernan, James M.; Ryan, Daniel; Warren, Harry

    2015-10-01

    We compare the ability of 11 differential emission measure (DEM) forward-fitting and inversion methods to constrain the properties of active regions and solar flares by simulating synthetic data using the instrumental response functions of the Solar Dynamics Observatory/Atmospheric Imaging Assembly (SDO/AIA) and EUV Variability Experiment (SDO/EVE), the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), and the Geostationary Operational Environmental Satellite/X-ray Sensor (GOES/XRS). The codes include the single-Gaussian DEM, a bi-Gaussian DEM, a fixed-Gaussian DEM, a linear spline DEM, the spatial-synthesis DEM, the Monte-Carlo Markov Chain DEM, the regularized DEM inversion, the Hinode/X-Ray Telescope (XRT) method, a polynomial spline DEM, an EVE+GOES, and an EVE+RHESSI method. Averaging the results from all 11 DEM methods, we find the following accuracies in the inversion of physical parameters: the EM-weighted temperature Tw^{fit}/Tw^{sim}=0.9±0.1, the peak emission measure EMp^{fit}/EMp^{sim}=0.6±0.2, the total emission measure EMt^{fit}/EMt^{sim}=0.8±0.3, and the multi-thermal energies E_{th}^{fit}/EM_{th}^{approx}=1.2±0.4. We find that the AIA spatial-synthesis, the EVE+GOES, and the EVE+RHESSI method yield the most accurate results.

  11. The Greenland Ice Sheet, now in HD

    NASA Astrophysics Data System (ADS)

    Howat, I. M.; Noh, M. J.; Porter, C. C.; Morin, P. J.; Herried, B.

    2014-12-01

    We are constructing very-high resolution (2 m of the margin, 10 m of the interior) Digital Elevation Model (DEM) and orthoimage mosaics of the the Greenland Ice Sheet from stereoscopic-mode satellite imagery acquired by the Worldview constellation and archived at the Polar Geospatial Center. The DEMs are constructed with the fully-automated Surface Extraction from TIN-based Search Minimization (SETSM) software developed by Ohio State University specifically for DEM extraction over high latitude terrains. The SETSM algorithm features an iterative process for correcting biases in the imagery geolocation information, improving DEM success over low-contrast and repetitively-textured surfaces such as snow and mountain shadows. The imagery are orthorectified using the corresponding DEM and individual orthoimages and DEMs are mosaiced into continuous tiles of coverage. To facilitate change detection, each pixel contains an acquisition date stamp and a flag indicating if the DEM pixel was measured or interpolated. The data are openly available online with registration at http://www.pgc.umn.edu/elevation/stereo . Here we present the Greenland DEM and orthoimage mosaics with examples of applications and comparisons to existing datasets. We compare the DEM's to coincident laser altimeter measurements to examine accuracies and potential biases, as well as discuss the feasibility of merging the DEMs with coordinated laser altimeter surveys to improve the spatial coverage of high-precision elevation data.

  12. Benchmark Test of Differential Emission Measure Codes and Multi-thermal Energies in Solar Active Regions

    NASA Astrophysics Data System (ADS)

    Aschwanden, Markus J.; Boerner, Paul; Caspi, Amir; McTiernan, James M.; Ryan, Daniel; Warren, Harry

    2015-10-01

    We compare the ability of 11 differential emission measure (DEM) forward-fitting and inversion methods to constrain the properties of active regions and solar flares by simulating synthetic data using the instrumental response functions of the Solar Dynamics Observatory/ Atmospheric Imaging Assembly (SDO/AIA) and EUV Variability Experiment (SDO/EVE), the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), and the Geostationary Operational Environmental Satellite/ X-ray Sensor (GOES/XRS). The codes include the single-Gaussian DEM, a bi-Gaussian DEM, a fixed-Gaussian DEM, a linear spline DEM, the spatial-synthesis DEM, the Monte-Carlo Markov Chain DEM, the regularized DEM inversion, the Hinode/ X-Ray Telescope (XRT) method, a polynomial spline DEM, an EVE+GOES, and an EVE+RHESSI method. Averaging the results from all 11 DEM methods, we find the following accuracies in the inversion of physical parameters: the EM-weighted temperature Tw^{fit}/Tw^{sim}=0.9±0.1, the peak emission measure EMp^{fit}/EMp^{sim}=0.6±0.2, the total emission measure EMt^{fit}/EMt^{sim}=0.8±0.3, and the multi-thermal energies E_{th}^{fit}/EM_{th}^{approx}=1.2±0.4. We find that the AIA spatial-synthesis, the EVE+GOES, and the EVE+RHESSI method yield the most accurate results.

  13. Assessing the quality for hydrological applications of digital elevation models derived from contours

    NASA Astrophysics Data System (ADS)

    Wise, Stephen

    2000-07-01

    Digital elevation models (DEMs) are becoming increasingly important tools in hydrological research and in water resources management. The quality of DEMs, however, normally is reported simply as the root mean square error of elevation, a statistic that fails to capture the numerous sources of error in DEMs or to predict their effect on the result of using the DEM. This paper presents a review of other approaches to assessing DEM quality, and argues that a full assessment of DEM quality must focus on the accuracy and reliability of the final product of the DEM analysis. A number of DEMs for the Slapton Ley catchments in Devon derived from digitized contour data are compared in an initial assessment of their sustainability for use in hydrological work. Two are available for purchase from data suppliers, and five more were created using a variety of interpolation techniques in widely available geographical information system software. The different interpretation methods produce DEMs with different artefacts, although analyses of the distribution of elevation values, and visual techniques, suggested that none of these were of a particularly pronounced nature. The results of using the DEMs to derive drainage networks and catchment areas showed that at the broad scale there was a high level of agreement between the DEMs. There were, however, important differences of detail. For example, some DEMs predicted drainage lines that occasionally crossed the original contours. The results of calculating the TOPMODEL topographic index showed far more variation, because the index is calculated for each pixel in the area, rather than being an aggregate result derived from numerous pixels. The main conclusion was that care should always be taken to assess the quality of a DEM before attempting to use it, and that results should always be checked to ensure that they appear to be reasonable.

  14. A geomorphology-based approach for digital elevation model fusion - case study in Danang city, Vietnam

    NASA Astrophysics Data System (ADS)

    Tran, T. A.; Raghavan, V.; Masumoto, S.; Vinayaraj, P.; Yonezawa, G.

    2014-07-01

    Global digital elevation models (DEM) are considered a source of vital spatial information and find wide use in several applications. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global DEM (GDEM) and Shuttle Radar Topographic Mission (SRTM) DEM offer almost global coverage and provide elevation data for geospatial analysis. However, GDEM and SRTM still contain some height errors that affect the quality of elevation data significantly. This study aims to examine methods to improve the resolution as well as accuracy of available free DEMs by data fusion techniques and evaluating the results with a high-quality reference DEM. The DEM fusion method is based on the accuracy assessment of each global DEM and geomorphological characteristics of the study area. Land cover units were also considered to correct the elevation of GDEM and SRTM with respect to the bare-earth surface. The weighted averaging method was used to fuse the input DEMs based on a landform classification map. According to the landform types, the different weights were used for GDEM and SRTM. Finally, a denoising algorithm (Sun et al., 2007) was applied to filter the output-fused DEM. This fused DEM shows excellent correlation to the reference DEM, having a correlation coefficient R2 = 0.9986, and the accuracy was also improved from a root mean square error (RMSE) of 14.9 m in GDEM and 14.8 m in SRTM to 11.6 m in the fused DEM. The results of terrain-related parameters extracted from this fused DEM such as slope, curvature, terrain roughness index and normal vector of topographic surface are also very comparable to reference data.

  15. Google Earth's derived digital elevation model: A comparative assessment with Aster and SRTM data

    NASA Astrophysics Data System (ADS)

    Rusli, N.; Majid, M. R.; Din, A. H. M.

    2014-02-01

    This paper presents a statistical analysis showing additional evidence that Digital Elevation Model (DEM) derived from Google Earth is commendable and has a good correlation with ASTER (Advanced Space-borne Thermal Emission and Reflection Radiometer) and SRTM (Shuttle Radar Topography Mission) elevation data. The accuracy of DEM elevation points from Google Earth was compared against that of DEMs from ASTER and SRTM for flat, hilly and mountainous sections of a pre-selected rural watershed. For each section, a total of 5,000 DEM elevation points were extracted as samples from each type of DEM data. The DEM data from Google Earth and SRTM for flat and hilly sections are strongly correlated with the R2 of 0.791 and 0.891 respectively. Even stronger correlation is shown for the mountainous section where the R2 values between Google Earth's DEM and ASTER's and between Google Earth's DEM and SRTM's DEMs are respectively 0.917 and 0.865. Further accuracy testing was carried out by utilising the DEM dataset to delineate Muar River's watershed boundary using ArcSWAT2009, a hydrological modelling software. The result shows that the percentage differences of the watershed size delineated from Google Earth's DEM compared to those derived from Department of Irrigation and Drainage's data (using 20m-contour topographic map), ASTER and SRTM data are 9.6%, 10.6%, and 7.6% respectively. It is therefore justified to conclude that the DEM derived from Google Earth is relatively as acceptable as DEMs from other sources.

  16. Exploitation of satellite optical and SAR data for public work studies

    NASA Astrophysics Data System (ADS)

    Ioannidis, Charalabos; Soile, Sofia; Stamos, Athanassios; Vassilaki, Dimitra; Maltezos, Evangelos; Verykokou, Styliani

    2015-06-01

    This paper studies the use of high resolution satellite optical and SAR images for 1:5,000 mapping production, which is essential for public work and environmental impact assessment studies. The images were used for the extraction of DEMs and their "fit for purpose" use was investigated, through the examination of parameters like accuracy, reliability and performance of morphological features. Orthoimages from satellite optical images using the produced DEMs with or without breaklines were produced. An application was developed on Antiparos island, a Greek island with irregular terrain. The data includes: (a) a triplet of Pleiades (1A, tri-stereo) satellite images, with a resolution of 0.5m, (b) a TanDEM-X Intermediate DEM, a preliminary version of the forthcoming TanDEM-X global DEM, and (c) an accurate DEM produced from the Greek National Cadastre & Mapping Agency S.A. was used as the reference DEM. The georeferencing of the optical images was computed using GCPs which were measured with GNSS. DEMs were extracted using all the possible combinations of the images triplet using automated image matching without any filtering or editing and were evaluated using the reference DEM. The combination of images which yielded the best DEM was then used to manually editing 3D points and collecting breaklines in order to produce a better DEM, which was also evaluated using various statistical measures and geo-morphological features. Orthoimages were created and evaluated using DEMs from optical and SAR data. A discussion about the use of the computed mapping products for the various stages of the public work studies is included.

  17. Allgemeine Sprachfaehigkeit und Fremdsprachenerwerb. Zur Struktur von Leistungsdimensionen und linguistischer Kompetenz des Fremdsprachenlerners (General Language Ability and Foreign Language Acquisition. On the Structure of Performance Dimensions and the Linguistic Competence of the Foreign Language Learner). Diskussions beitraege aus dem Institute fuer Bildungsforschung, No. 1.

    ERIC Educational Resources Information Center

    Sang, Fritz; Vollmer, Helmut J.

    This study investigates the theoretical plausibility and empirical validity of the assumption that all performance in a foreign language can be traced back to a single factor, the general language ability factor. The theoretical background of this hypothesis is reviewed in detail. The concept of a unitary linguistic competence, interpreted as an…

  18. Künstliche Heißzeit: Neuer Bericht zum Weltklima

    NASA Astrophysics Data System (ADS)

    Kohl, Harald

    2002-09-01

    Der neue Bericht des Intergovernmental Panel on Climate Change belegt eine wachsende Evidenz für einen globalen Klimawandel. Modelle deuten überdies darauf hin, dass menschliche Aktivitäten entscheidend zu dieser Entwicklung beigetragen haben. So sind seit 1750 die atmosphärischen Konzentrationen von Distickstoffoxid und 17 Prozent, von Kohlendioxid um rund ein Drittel und die von Methan sogar auf das Zweieinhalbfache gestiegen. Modelle sagen aufgrund dessen für das 21. Jahrhundert eine Erhöhung der mittleren Globaltemperatur zwischen 1, 5 und 4, 5 Grad Celsius und einen Anstieg des Meeresspiegels zwischen 0, 3 und 0, 7 Meter voraus.

  19. Wirkungen biogener Amine auf die Erregungs-Sekretions-Kopplung in der Speicheldrüse von Periplaneta americana (L.)

    NASA Astrophysics Data System (ADS)

    Rietdorf, Katja

    2003-07-01

    In der vorliegenden Arbeit habe ich wichtige Teilmechanismen der Erregungs-Sekretionskopplung in der Speicheldrüse der Schabe Periplaneta americana (L.) untersucht. Die Speicheldrüse ist von dopaminergen und serotonergen Fasern innerviert (Baumann et al., 2002). Beide Transmitter stimulieren eine unterschiedliche Reaktion der Drüse: Dopamin (DA) stimuliert die P-Zellen der Acini und die Ausführgangzellen, während Serotonin (5-HT) die P- und C-Zellen der Acini stimuliert, nicht jedoch die Ausführgangzellen. Der Endspeichel ist nach einer DA-Stimulierung proteinfrei. Dagegen enthält er nach einer 5-HT-Stimulierung Proteine, die von den C-Zellen sezerniert werden (Just & Walz, 1996). Im ersten Teil meiner Arbeit habe ich mittels Kapillarelektrophoretischer Analyse (CE-Analyse) die Elektrolytkonzentrationen im Endspeichel untersucht sowie die Raten der Flüssigkeitssekretion gemessen. Damit wollte ich klären, welche Transporter an der Sekretion des Primärspeichels und an dessen Modifikation beteiligt sind. Ausserdem wollte ich die Rolle der transportaktiven Epithelzellen der Ausführgänge für die Modifikation des Primärspeichels untersuchen. Dafür habe ich einen Vergleich der Elektrolytkonzentrationen im DA- und 5-HT-stimulierten Endspeichel durchgeführt. Der Elektrolytgehalt des DA- und 5-HT-stimulierten Endspeichels unterscheidet sich nicht signifikant voneinander. Er ist nach beiden Stimulierungen hypoosmotisch zum verwendeten Ringer. Die Ausführgangzellen werden durch DA stimuliert und modifizieren den Primärspeichel durch eine netto-Ionenreabsorption. Meine Versuche zeigen jedoch, dass auch die während einer 5-HT-Stimulierung der Drüse unstimulierten Ausführgangzellen den Primärspeichel modifizieren. In einer nachfolgenden Versuchsreihe habe ich den Einfluss von Ouabain, einem Hemmstoff der Na+-K+-ATPase, und Bumetanid, einem Hemmstoff des NKCC, auf die Raten der Flüssigkeitssekretion sowie den Elektrolytgehalt des Endspeichels untersucht. Ich habe gefunden, dass die Aktivität der Na+-K+-ATPase wichtig für die Modifikation des DA-stimulierten Primärspeichels ist. Im Gegensatz dazu ist sie für die Modifikation des 5-HT-stimulierten Primärspeichels nicht von Bedeutung. Bezüglich der Flüssigkeitssekretion habe ich keinen Einfluss der Na+-K+-ATPase-Aktivität auf die DA-stimulierten Sekretionsraten gefunden, dagegen ist die 5-HT-stimulierte Sekretionsrate in Anwesenheit von Ouabain gesteigert. Die Aktivität des NKCC ist für beide sekretorische Prozesse, die Ionen- und die Flüssigkeitssekretion, wichtig. Eine Hemmung des NKCC bewirkt eine signifikante Verringerung der Raten der Flüssigkeitssekretion nach DA- und 5-HT-Stimulierung sowie in beiden Fällen einen signifikanten Abfall der Ionenkonzentrationen im Endspeichel. Im zweiten Teil meiner Arbeit habe ich versucht, Änderungen der intrazellulären Ionenkonzentrationen in den Acinuszellen während einer DA- oder 5-HT-Stimulierung zu messen. Diese Experimente sollten mit der Methode des "ratiometric imaging" durchgeführt werden. Messungen mit dem Ca2+-sensitiven Fluoreszenzfarbstoff Fura-2 zeigten keinen globalen Anstieg in der intrazellulären Ca2+-Konzentration der P-Zellen. Aufgrund von Problemen mit einer schlechten Beladung der Zellen, einer starken und sich während der Stimulierung ändernden Autofluoreszenz der Zellen sowie Änderungen im Zellvolumen wurden keine Messungen mit Na+- und K+-sensitiven Fluoreszenzfarbstoffen durchgeführt. Im dritten Teil dieser Arbeit habe ich die intrazellulären Signalwege untersucht, die zwischen einer 5-HT-Stimulierung der Drüse und der Proteinsekretion vermitteln. Dazu wurde der Proteingehalt im Endspeichel biochemisch mittels eines modifizierten Bradford Assay gemessen. Eine erstellte Dosis-Wirkungskurve zeigt, dass die Rate der Proteinsekretion von der zur Stimulierung verwendeten 5-HT-Konzentration abhängt. In einer Serie von Experimenten habe ich die intrazellulären Konzentrationen von Ca2+, cAMP und / oder cGMP erhöht und anschließend den Proteingehalt im Endspeichel gemess

  20. TissuePatch™ as a novel synthetic sealant for repair of superficial lung defect: in vitro tests results

    PubMed Central

    2012-01-01

    Background Controversies surrounding the efficacy of surgical sealants against alveolar air leaks (AAL) in lung surgery abound in the literature. We sought to test the sealing efficacy of a novel synthetic sealant, TissuePatch™ in an in vitro lung model. Methods The lower lobe of freshly excised swine lung (n?=?10) was intubated and ventilated. A superficial parenchymal defect (40?×?25 mm) was created, followed by AAL assessment. After sealant application, AAL was assessed again until burst failure occurred. The length of defect was recorded to evaluate the elasticity of the sealant. Results Superficial parenchymal defects resulted in AAL increasing disproportionally with ascending maximal inspiratory pressure (Pmax). Multiple linear regression analysis revealed strong correlation between AAL and Pmax, compliance, resistance. After sealant application, AAL was sealed in all ten tests at an inspired tidal volume (TVi) of 400 ml, in nine tests at TVi?=?500 ml, in seven at TVi?=?600 ml and in five at TVi?=?700 ml. The mean burst pressure was 42?±?9 mBar. Adhesive and cohesive sealant failures were found in six and three tests respectively. The length of defect before sealant failure was 8.9?±?4.9% larger than that at TVi?=?400 ml, demonstrating an adequate elasticity of this sealant film. Conclusions TissuePatch™ may be a reliable sealant for alternative or adjunctive treatment for repair of superficial parenchymal defects in lung surgery. The clinical benefits of this sealant should be confirmed by prospective, randomised controlled clinical trials. Abstrakt Hintergrund Die Wirksamkeit von chirurgischen Klebstoffen zur Prävention von alveolo-pleuralem Luftleck (APL) ist trotz zunehmenden klinischen Anwendungen in Lungenchirurgie immer noch kontrovers diskutiert. Wir evaluierten die Abdichtungswirksamkeit von einem neuartigen synthetischen Kleber, TissuePatch™ mittels eines in vitro Lungenmodels. Methode Der Unterlappen von frisch entnommenen Schweinlungen (n?=?10) wurde intubiert und beatmet. Eine pleurale Läsion (40?×?25 mm) wurde erstellt und APL mit steigendem inspiratorischem Tidalvolumen (TVi) untersucht. Nach Applikation von TissuePatch™ wurde APL auf die gleiche Weise gemessen bis zur Auftritt von Kleberbruch. Zur Untersuchung der Elastizität des Klebers wurde die Länge der pleuralen Läsion gemessen. Ergebnis Pleurale Läsion führte bei aufsteigendem maximalem inspiratorischem Druck (Pmax) zu überproportionalem Anstieg von APL. Multiple lineare Regressionsanalyse ergab eine starke Korrelation zwischen APL und Pmax, Lungencompliance sowie Widerstand. Nach der Applikation von Klebstoff wurde APL bei TVi?=?400 ml in allen zehn Testen versiegelt, bei TVi?=?500 ml in neun Testen, bei TVi?=?600 ml in sieben und bei TVi?=?700 ml in fünf Testen. Der mittlere Pmax, der zu Kleberbruch führte, betrug 42?±?9 mBar. Bei den Versuchen wurden adhäsiver und kohäsiver Kleberbruch in jeweils sechs und drei Testen gefunden. Die Länge der pleuralen Läsion vor dem Kleberbruch war 8,9?±?4,9% größer als die bei TVi?=?400 ml. Schlussfolgerung Unsere Versuche zeigten eine zuverlässige Versiegelung von TissuePatch™ unter mechanischer Ventilation. Die klinische Nützlichkeit vom Kleber als unterstützende Maßnahme zur Prävention von alveolo-pleuralem Luftleck in Lungenchirurgie sollte durch prospektive, randomisierte kontrollierte klinische Studien bestätigt werden. PMID:23164337

  1. Der obere Mantel in der Eifel-Region untersucht mit der Receiver Function Methode. (English Title: The upper mantle in the region of the Eifel, Germany, analyzed with the receiver function method)

    NASA Astrophysics Data System (ADS)

    Budweg, Martin

    2003-03-01

    Die Eifel ist eines der jüngsten vulkanischen Gebiete Mitteleuropas. Die letzte Eruption ereignete sich vor ungefähr 11000 Jahren. Bisher ist relativ wenig bekannt über die tieferen Mechanismen, die für den Vulkanismus in der Eifel verantwortlich sind. Erdbebenaktivität deutet ebenso darauf hin, dass die Eifel eines der geodynamisch aktivsten Gebiete Mitteleuropas ist. In dieser Arbeit wird die Receiver Function Methode verwendet, um die Strukturen des oberen Mantels zu untersuchen. 96 teleseismische Beben (mb > 5.2) wurden ausgewertet, welche von permanenten und mobilen breitbandigen und kurzperiodischen Stationen aufgezeichnet wurden. Das temporäre Netzwerk registrierte von November 1997 bis Juni 1998 und überdeckte eine Fläche von ungefähr 400x250 km². Das Zentrum des Netzwerkes befand sich in der Vulkaneifel. Die Auswertung der Receiver Function Analyse ergab klare Konversionen von der Moho und den beiden Manteldiskontinuitäten in 410 km und 660 km Tiefe, sowie Hinweise auf einen Mantel-Plume in der Region der Eifel. Die Moho wurde bei ungefähr 30 km Tiefe beobachtet und zeigt nur geringe Variationen im Bereich des Netzwerkes. Die beobachteten Variationen der konvertierten Phasen der Moho können mit lateralen Schwankungen in der Kruste zu tun haben, die mit den Receiver Functions nicht aufgelöst werden können. Die Ergebnisse der Receiver Function Methode deuten auf eine Niedriggeschwindigkeitszone zwischen 60 km bis 90 km in der westlichen Eifel hin. In etwa 200 km Tiefe werden im Bereich der Eifel amplitudenstarke positive Phasen von Konversionen beobachtet. Als Ursache hierfür wird eine Hochgeschwindigkeitszone vorgeschlagen, welche durch mögliches aufsteigendes, dehydrierendes Mantel-Material verursacht wird. Die P zu S Konversionen an der 410 km Diskontinuität zeigen einen späteren Einsatz als nach dem IASP91-Modell erwartet wird. Die migrierten Daten weisen eine Absenkung der 410 km Diskontinuität um bis zu 20 km Tiefe auf, was einer Erhöhung der Temperatur von bis zu etwa 140° Celsius entspricht. Die 660 km Diskontinuität weist keine Aufwölbung auf. Dies deutet darauf hin, dass kein Mantelmaterial direkt von unterhalb der 660 km Diskontinuität in der Eifel-Region aufsteigt oder, dass der Ursprung des Eifel-Plumes innerhalb der Übergangszone liegt. The upper mantle in the region of the Eifel, Germany, analyzed with the receiver function method: The Eifel is the youngest volcanic area of Central Europe. The last eruption occurred approximately 11000 years ago. Little is known about the deep origin and the mechanism responsible for the Eifel volcanic activity. Earthquake activity indicates that the Eifel is one of the most geodynamically active areas of Central Europe. In this work the receiver function method is used to investigate the upper mantle structure beneath the Eifel. Data from 96 teleseismic events (mb > 5.2) that were recorded by both permanent stations and a temporary network of 33 broadband and 129 short period stations had been analyzed. The temporary network was operating from November 1997 till June 1998 and covered an area of approximately 400x250 km² centered on the Eifel volcanic fields. The receiver function analysis reveals a clear image of the Moho and the mantle discontinuities at 410 km and 660 km depth. Average Moho depth is approximately 30 km and it shows little variation over the extent of the network. The observed variations of converted waveforms are possibly caused by lateral variations in crustal structure, which could not resolved by it receiver functions. Inversions of data and migrated it receiver functions from stations of the central Eifel array suggest that a low velocity zone is present at about 60 to 90 km depth in the western Eifel region. There are also indications for a high velocity zone around 200 km depth, perhaps caused by dehydration of the rising plume material. The results suggest that P-to-S conversions from the 410-km discontinuity arrive later than in the IASP91 reference model. The migrated data show a depression of the 410 k

  2. ADLATUS Interface CD für Schulen am Beispiel der Erdatmosphäre: Ein Pilotprojekt

    NASA Astrophysics Data System (ADS)

    Hartmann, G. K.; Nölle, A.; Dettmer, G.; Putz, E.

    2003-05-01

    The goal of the presented pilot project is the creation of a modular interactive online and offline interface on CD which can be used between schools, various information sources and the science community, i.e. actual, new research results should be made available for students from elementary schools to high schools in an uncomplicated - school and age specific - form. At the beginning this interface will be realised using as an example the existing knowledge about the Earth atmosphere followed by other topics like (drinking) water, energy, soil, and raw material etc. The interactive, interface concept "ADLATUS for schools", which is a further development of the scientific DUST-2 CD, however, complements and interrelates for the first time this information with a so called "local, school specific" part - about 20% of the CD storage space will be reserved for that - to be generated according to the "individual" school and environmental conditions in special co-operative teaching and learning teams. For the selected topic the ADLATUS CD will contain global and regional background information, examples for time series data, links, and software (freeware and shareware), especially for an interactive graphic representation of the information. The CD should be updated at least every second year. It will document the results of a direct dynamic interrelationship between the geo-science community, elementary schools and other school types. It will be beneficial for the future of both and other science domains that will follow. Ziel des hier vorgeschlagenen Pilotprojekts ist die Erstellung einer modular aufgebauten interaktiven online und offline Schnittstelle (Interface) auf CD, die Schulen mit verschiedenen Informationsquellen und der Wissenschaftsgemeinschaft verbinden kann und so aktuelle wissenschaftliche Forschungsergebnisse den Schülern von der Grundschule bis hin zum Gymnasium in möglichst einfacher, verständlicher und altersgemäßer Form vermittelt. Dieses Interface soll in einer ersten Stufe am Beispiel unseres Wissens über die Erdatmosphäre realisiert werden, gefolgt von den Themen (Trink)Wasser, Energie, Boden und Rohstoffe. Das interaktive Interface-Konzept "ADLATUS f¨ur Schulen", eine Weiterentwicklung der DUST-2 CD - vorwiegend für die Wissenschaftsgemeinde gedacht - ergänzt und verknüpft zum ersten Mal diese Informationen mit einem "schulspezifischen Lokalteil", für den etwa 20% des CD Speicherplatzes vorgesehen werden, und der von den einzelnen Schulen lehrplanspezifisch, lehrerspezifisch und ortspezifisch in Lehr- und Lernteams selbst "erzeugt" werden soll. Die ADLATUS CD wird zu dem ausgewählten Thema globale und regionale Hintergrundinformationen, Zeitreihendaten, Links, und Software (Shareware oder Freeware) enthalten, insbesondere zur interaktiven graphischen Darstellung der Informationen. Sie soll spätestens alle zwei Jahre auf den neuesten Stand gebracht werden. Sie wird die Ergebnisse einer direkten, dynamischen Wechselwirkung zwischen der Geo-Wissenschaftsgemeinschaft, den Grundschulen und anderen Schultypen dokumentieren und für die Zukunft beider nützlich sein - ebenso für die anderen nachfolgenden Wissenschafts- und Technikbereiche.

  3. A viewshed accuracy assessment: Comparison of field-derived and computer-derived viewsheds

    NASA Astrophysics Data System (ADS)

    Sims, Brian Russell

    2011-12-01

    A viewshed is the visible area from an observation location, or what can be seen from a particular vantage point. Viewsheds are calculated using Digital Elevation Models (DEMs) and are used widely by the wireless communications industry, city planners, and military planners. The goal of this research was to determine which combination of DEM interpolation methods and spatial resolutions result in the most accurate DEM and which DEMs produce the most accurate viewsheds. Results indicate the most accurate viewshed was computed from a surface generated from one of the least accurate DEMs (inverse distance weighted at 10 meter spatial resolution). DEM-derived viewsheds vary by as little as 60 percent and as much as 116 percent from field-derived calculations. The variation of the computer-derived viewshed always under predicted the visible area. This research highlights some limitations in the viewshed calculation and serves as a caution to users of viewsheds computed from commercial geographic information system software.

  4. Assessment of Required Accuracy of Digital Elevation Data for Hydrologic Modeling

    NASA Technical Reports Server (NTRS)

    Kenward, T.; Lettenmaier, D. P.

    1997-01-01

    The effect of vertical accuracy of Digital Elevation Models (DEMs) on hydrologic models is evaluated by comparing three DEMs and resulting hydrologic model predictions applied to a 7.2 sq km USDA - ARS watershed at Mahantango Creek, PA. The high resolution (5 m) DEM was resempled to a 30 m resolution using method that constrained the spatial structure of the elevations to be comparable with the USGS and SIR-C DEMs. This resulting 30 m DEM was used as the reference product for subsequent comparisons. Spatial fields of directly derived quantities, such as elevation differences, slope, and contributing area, were compared to the reference product, as were hydrologic model output fields derived using each of the three DEMs at the common 30 m spatial resolution.

  5. Extraction of terrain features from digital elevation models

    USGS Publications Warehouse

    Price, Curtis V.; Wolock, David M.; Ayers, Mark A.

    1989-01-01

    Digital elevation models (DEMs) are being used to determine variable inputs for hydrologic models in the Delaware River basin. Recently developed software for analysis of DEMs has been applied to watershed and streamline delineation. The results compare favorably with similar delineations taken from topographic maps. Additionally, output from this software has been used to extract other hydrologic information from the DEM, including flow direction, channel location, and an index describing the slope and shape of a watershed.

  6. J-holomorphic curves in cotangent bundles and the heat ow

    E-print Network

    Weber, Joa

    Randwertproblem { als einen adiabatischen Limes des Floerschen Gradienten usses auf dem Schleifenraum von T M { ein elliptisches Randwertproblem. In diesem Limes wird die vertikale Komponente der induzierten Metrik

  7. Analysis of accuracy of digital elevation models created from captured data by digital photogrammetry method

    NASA Astrophysics Data System (ADS)

    Hudec, P.

    2011-12-01

    A digital elevation model (DEM) is an important part of many geoinformatic applications. For the creation of DEM, spatial data collected by geodetic measurements in the field, photogrammetric processing of aerial survey photographs, laser scanning and secondary sources (analogue maps) are used. It is very important from a user's point of view to know the vertical accuracy of a DEM. The article describes the verification of the vertical accuracy of a DEM for the region of Medzibodrožie, which was created using digital photogrammetry for the purposes of water resources management and modeling and resolving flood cases based on geodetic measurements in the field.

  8. Nr 4 Juni 2010 Hippologenhetens Nyhetsbrev

    E-print Network

    dem. Grundlig, kontakter, livsstil" Foto: ASVH Carolina Rytterkull 94-96 "Jag jobbade på ridskola gymnasieprogrammet, bytte till min nuvarande tjänst 2004. Beprövad erfarenhet, vetenskaplighet, nätverk." Foto

  9. Rtsel um Sauerstoff drfte gelst sein http://derstandard.at/druck/?id=2037748 1 of 2 5/6/2005 9:08 AM

    E-print Network

    Fennel, Katja

    Stickstoffverbindungen, einem Grundnahrungsmittel der Lebewesen, meinen Katja Fennel und Paul Falkowski von der Rutgers diesem Teufelskreis? Fennel und Falkowski meinen, die Ursache liege unter dem Meeresboden. Nach einiger

  10. Modernisierung von 3270-Host-Anwendungen mit

    E-print Network

    Spruth, Wilhelm G.

    virtuellen Maschine mit z/Linux auf dem zSeries Mainframe der Universität Tübingen lauähig gemacht. Zu Demon. Grundlagen 3 2.1. Mainframe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

  11. Vorkurs 2015 Die Fakultt fr Physik und Astronomie bietet in der Zeit von

    E-print Network

    Gerwert, Klaus

    Vorkurs 2015 Die Fakultät für Physik und Astronomie bietet in der Zeit von Montag, 07.09.2015 bis Freitag, 02.10.2015 für künftige Studentinnen und Studenten einen Vorkurs an: Einführung in die, die mathematischen Schwierigkeiten zu überbrücken, die beim Übergang zwischen Schule und Studium

  12. Mitteilung fr die Medien Mitteilung fr die Medien Mitteilung fr die Medien Mitteilung fr die Medien Eine Zeile mit 39 Anschlgen (mit Leerzeichen) durchschnittlich

    E-print Network

    Dettweiler, Michael

    Mitteilung für die Medien Mitteilung für die Medien Mitteilung für die Medien Mitteilung für die Hochschulleitung war die hochschulpolitische Sprecherin der Grünen im Bayerischen Landtag, Ulrike Gote (Dritte von rechts), auf den Campus gekommen. Gemeinsame Sorge um die Qualität Gespräch zwischen Hochschulleitung und

  13. MensaCard Kids kostenloses Essen in der Mensa fr Kinder von Studierenden

    E-print Network

    Manstein, Dietmar J.

    MensaCard Kids kostenloses Essen in der Mensa für Kinder von Studierenden ... wird fortgesetzt Über vereinbaren, ist nicht immer einfach. Deshalb unterstützen wir Sie mit der MensaCard Kids für Kinder zwischen 0 und 10 Jahren! Die MensaCard Kids wird finanziert aus Mitteln des Studentenwerks Hannover. audit

  14. 13.1.2010 Thema fur eine Studienarbeit Erweiterung des Back-Ends der Open Sesame Anwendung

    E-print Network

    Borchert, Bernd

    , der auch das Foto-PIN Verfahren einschließt, soll durch folgende Erweiterungen verbessert werden initialisieren ihr Handy durch Scannen eines auf einem pdf dargestellten 2D-Codes. Foto-PIN Auch das Foto-PIN Verfahren (aber nicht das Foto-TAN Verfahren) soll integriert werden. Der Benutzer soll zwischen Open Sesame

  15. Ökonometrie

    NASA Astrophysics Data System (ADS)

    Frohn, Joachim

    Die Ökonometrie, als eine Wissenschaft auf der Schnittstelle zwischen Mathematik, Statistik und den Wirtschaftswissenschaften, ist auch in der Deutschen Statistischen Gesellschaft (DStatG) zu einer tragenden Säule geworden. Das vorliegende Kapitel gibt einen kurzen Überblick über die Entwicklung der wichtigsten Gebiete der Ökonometrie und die Arbeit im "Ausschuss für Empirische Wirtschaftsforschung und Angewandte Ökonometrie".

  16. Historisches Rätsel Ein Forscher ohne Angst vorm Vakuum

    NASA Astrophysics Data System (ADS)

    Loos, Andreas

    2004-07-01

    Mit 30.000 Einwohnern gehörte seine Geburtsstadt zu einer der größeren Städte Deutschlands - und seine Familie zu einer der großen Familien dieser Stadt: Zwischen 1532 und 1630 trugen 19 Bürgermeister seinen Nachnamen; in den 30 Jahren davor stellte sein Geschlecht 22 Stadtkämmerer.

  17. Die Detektionsgrenze der MR-Spektroskopie mittels intermolekularen Nullquantenkohrenzen in inhomogenen Magnetfeldern

    E-print Network

    . Voraussetzung für hoch- wertige MR-Spektren ist eine hervorragende Homo- genität des Hauptmagnetfeldes (B0cos2 IS ­ 1, mit IS = Winkel zwischen Distanzvektor und B0), vernach- lässigt. Die radiale Symmetrie schwachen Beitrag der modu- lierten z-Magnetisierung (Mz(r)) zum lokalen Magnet- feld, das sog. ,,distant

  18. Finanzmanagement in den Marie Curie-Manahmen

    E-print Network

    Kaus, Boris

    Finanzmanagement in den Marie Curie-Maßnahmen 2007-2013 Version 4 Stand September 2013 #12;Marie Curie-Finanzübersicht 2007-2013 Version 4, Stand September 2013 Wesentliche Änderungen zur Version 3 vom Vorfinanzierung auf 30 Tage und die der Zwischen- und Abschlusszahlung auf 90 Tage verkürzt. #12;Marie Curie

  19. Gerhard Ertl 78 M A X P L A N C K F O R S C H U N G 4 / 2 0 0 7

    E-print Network

    Falge, Eva

    Berliner Fritz-Haber-Institut der Max-Planck-Gesellschaft, trägt seit 10. Dezember offiziell den Nobelpreis entwickelt haben Fritz Haber und Carl Bosch, beide ebenfalls Nobel- preisträger, zwischen 1905 und 1913. Doch den wesentlichen Schritt des Haber-Bosch-Verfahrens ­ die Reak- tion, die sich an der Oberfläche des

  20. INAUGURAL-DISSERTATION Erlangung der Doktorwrde

    E-print Network

    Gertz, Michael

    measuring technique was used, which is based on optical heating and paramagnetic temperature sensors an adiabatic nuclear demagnetization refrigerator was set up. For measuring the base temperature a novel noise Abweichungen vom erwarteten linearen Verhalten zwischen der Rauschleistung und der Temperatur festgestellt

  1. Medizinische Hochschule Hannover (MHH) -Der Personalrat -OE 9510 -Carl-Neuberg-Str. 1 -30625 Hannover Rahmendienstvereinbarung EDV-System SAP R/3

    E-print Network

    Manstein, Dietmar J.

    Hannover Rahmendienstvereinbarung EDV-System SAP R/3 zwischen der Medizinischen Hochschule Hannover-Softwaresystems SAP R/3 bzw. von Modulen und einzelnen Komponenten von SAP. Für in SAP erfaßte oder verarbeitete Daten-unterstützten Arbeitsplätze, die direkt mit SAP R/3 arbeiten oder über Schnittstellen mit SAP R/3 verknüpft sind sowie alle

  2. Abbildung 78: Collage von J.M. Harms ,,Die 30S ribosomale Untereinheit von Thermus thermophilus: Von den Kristallen zur Struktur." Die 2-dimensionale Struktur der 16S RNA

    E-print Network

    MPG Abbildung 78: Collage von J.M. Harms ,,Die 30S ribosomale Untereinheit von Thermus thermophilus: Von den Kristallen zur Struktur." Die 2-dimensionale Struktur der 16S RNA wurde aus Gutell et al. 2000 Beziehungen zwischen der Struktur und der Funktion von biologischen Makromolekülen. Thematische Schwerpunkte

  3. bungsaufgaben zum Freitag 14.6 1) Rntgen-Bragg Reflexion von Silizium

    E-print Network

    Wünsche, Hans-Jürgen "Ede"

    �bungsaufgaben zum Freitag 14.6 1) Röntgen-Bragg Reflexion von Silizium Bei welchem Winkel (zwischen Oberfläche des Kristalls und einfallendem Strahl) tritt der erste Bragg Reflex von Silizium auf (d Röntgenstrahlung. Zur Lösung sind Kristallstruktur von Si zu recherchieren, der Strukturfaktor der Einheitszelle zu

  4. Komplement#rpaare linearer Erweiterungen von Ordnungen

    E-print Network

    Felsner, Stefan

    Komplement#rpaare linearer Erweiterungen von Ordnungen Carsten Ihlemann 11. Juni 1999 Zusammenfassung Der Abstand zwischen zwei linearen Erweiterungen einer (Halb­)Ordnung ist die Anzahl der Paare von Elementen, die in den beiden Erweiterungen unterschiedlich geordnet sind. Ein Paar L; M von linearen

  5. Heft 13 Kurze Originalmitteilungen ~0J-1956 (Jg. 43)

    E-print Network

    Govindjee

    amino acids from the diseased leaves of Trichosanthes anguina BAWDEN and PIRIE 1) suggest that v [often- sichtlich MonokieselsXure] wandert mit einem RF-Wert yon 0, 75, w~thrend die dutch Kondensation entstandenen h6hermolekularen S~turen schneller wandern (RF- Werte zwischen 0,75 und 1). Dieses eigenartige

  6. Regionales Fachdidaktikzentrum (RFDZ) fr Mathematik Wien rfdzmathematik.univie.ac.at Das RFDZ Mathematik Wien ldt alle interessierten AHS-und BHS-

    E-print Network

    Pottmann, Helmut

    Katholizismus Prof. Dr. H. Henning (U Magdeburg): Probleme zwischen Himmel und Erde ­ Modellbildung überall Dr): Aufgaben variieren ­ produktiv Mathematik erfinden und erleben Prof. Dr. H. Henning (U Magdeburg): Ist.45 Plenarvortrag Prof. Dr. H.-W. Henn (TU Dortmund): Meinen Bogen setze ich in die Wolken Mittagspause: 11.45 ­ 13

  7. Die Gasultrazentrifuge als mediale Projektion des Kalten Krieges

    NASA Astrophysics Data System (ADS)

    Helmbold, Bernd

    Studien der letzten Dekaden nach der Wiedervereinigung von BRD und DDR erweitern die Perspektive der Wissenschaftsgeschichte vom Fokus des Big Science und der technisch-militärisch-industriellen Auseinandersetzung zwischen den zwei Blöcken zu einer globalen Transformation im Konflikt der Supermächte geprägt durch lokale und auch interne Ausformungen.

  8. Vamp Herbst 2014 9 Gesprch mit Prof. Hungerbhler

    E-print Network

    Hungerbühler, Norbert

    Gymnasium Universität. Dort sitzen Gymnasiallehrkrä e und Hoch- schuldozierende an einem Tisch und be- sprechen Probleme die beim Übergang zwischen Gymnasium und Hochschule entstehen können. Man hat zum Bei fachlicher Studier- kompetenzen am Gymnasium". Dies ist ein Projekt das an der Universität Zürich von

  9. Topogrid Derived 10 Meter Resolution Digital Elevation Model of the Shenandoah National Park and Surrounding Region, Virginia

    USGS Publications Warehouse

    Chirico, Peter G.; Tanner, Seth D.

    2004-01-01

    Explanation The purpose of developing a new 10m resolution DEM of the Shenandoah National Park Region was to more accurately depict geologic structure, surfical geology, and landforms of the Shenandoah National Park Region in preparation for automated landform classification. Previously, only a 30m resolution DEM was available through the National Elevation Dataset (NED). During production of the Shenandoah10m DEM of the Park the Geography Discipline of the USGS completed a revised 10m DEM to be included into the NED. However, different methodologies were used to produce the two similar DEMs. The ANUDEM algorithm was used to develop the Shenadoah DEM data. This algorithm allows for the inclusion of contours, streams, rivers, lake and water body polygons as well as spot height data to control the elevation model. A statistical analysis using over 800 National Geodetic Survey (NGS) first and second order vertical control points reveals that the Shenandoah10m DEM, produced as a part of the Appalachian Blue Ridge Landscape project, has a vertical accuracy of ?4.87 meters. The metadata for the 10m NED data reports a vertical accuracy of ?7m. A table listing the NGS control points, the elevation comparison, and the RMSE for the Shenandoah10m DEM is provided. The process of automated terrain classification involves developing statistical signatures from the DEM for each type of surficial deposit and landform type. The signature will be a measure of several characteristics derived from the elevation data including slope, aspect, planform curvature, and profile curvature. The quality of the DEM is of critical importance when extracting terrain signatures. The highest possible horizontal and vertical accuracy is required. The more accurate Shenandoah 10m DEM can now be analyzed and integrated with the geologic observations to yield statistical correlations between the two in the development of landform and surface geology mapping projects.

  10. Mapping from Formosat-2 stereo images: digital elevation model validation and accuracy assessment

    NASA Astrophysics Data System (ADS)

    Chen, Po-Li; Liu, Cheng-Chien

    2009-04-01

    Digital Elevation Model (DEM) generated from satellite stereo image data has been widely used in change detection of elevation, such as tracking the glacier movement, estimating the landslide volume, and mapping the surface topography. As the spatial resolution of satellite stereo image data is increasing, the generated DEM is expected to reveal more and more details of the topography. In addition, since the applications of rapid response are increasing, the time required to collect the satellite stereo image data is expected to get shortened as well. The successful operation of Formosat-2, launched on 21 May 2004, has enabled the collection of both high-spatial- (2 m) and high-temporal-resolution (daily) images. Together with its capability of pointing ±45 degrees to both along and across track directions, Formosat-2 is able to take stereo images for any scene in its coverage area. This provides an ideal source of stereo image data for rapidly generating a regional DEM to respond to the urgent needs in a timely manner. This research describes the procedure of generating a DEM from Formosat-2 stereo image data. The mountainous region of the catchment of Tseng-Wen Reservoir (TWR) is selected as the study area, where the orthorectified aerial photos (50 cm) and their derived DEMs (5 m) are available. A total of 120 ground control points (GCPs) are uniformly collected from one aerial photo and identified on the corresponded Formosat-2 stereo images, with the intention to build the rational polynomial coefficients (RPCs) of Formosat-2 orbit. A series of sensitivity tests are performed to examine how the generated DEM is influenced by various factors, including RPCs, tie points and GCPs. The accuracy of the generated DEM is assessed and validated against the aerial DEM, ASTER DEM, and SRTM DEM. The results demonstrate that Formosat-2 stereo image data is ideal for rapidly generating a regional DEM to respond to the urgent needs in a timely manner.

  11. Improving a digital elevation model by reducing source data errors and optimising interpolation algorithm parameters: An example in the Loess Plateau, China

    NASA Astrophysics Data System (ADS)

    Yang, QinKe; McVicar, Tim R.; Van Niel, Tom G.; Hutchinson, Michael F.; Li, LingTao; Zhang, XiaoPing

    2007-08-01

    A hydrologically correct digital elevation model (DEM) forms a basis for realistic environmental modelling, especially in complex terrain. We have performed a study in the Coarse Sandy Hilly Catchments (CSHC) of the Loess Plateau, China, which demonstrates pragmatic, yet effective methods for improving the quality of the DEM by: (1) identifying and correcting source topographic data errors and (2) optimising ANUDEM algorithm parameters. Improvement in the DEM based on fixing over 1100 errors in the input topographic data, and optimising key ANUDEM parameters was assessed using higher accuracy independent validation of 32 contributing areas and 1474 spot heights, and by semi-quantitative analysis of DEM derivatives produced from ANUDEM and Triangular Irregular Network (TIN) algorithms. Improvement in the ANUDEM DEM over the original TIN DEM was shown where the percentage of the total absolute difference in contributing areas reduced from 10.43 to 3.51%, and the bias between the spot heights and DEM elevations reduced from 45 to 32 m. Large improvement in DEM quality was gained by using ANUDEM instead of TIN, with smaller improvement gained by fixing source data errors, and optimising ANUDEM parameters.

  12. NOUN AND VERB GROUP IDENTIFICATION -Smriti Singh, Om P. Damani, Vaijayanthi M. Sarma

    E-print Network

    Damani, Om P.

    )* Set 4 (Set 5) (Particle) Some examples of Hindi NGs: Dem Pron+N, e.g., vo mez (that table) Poss pronoun+N, e.g., mer kmr (my room) Adj+N, e.g., sundr lk (beautiful girl) Dem pron+Adj+N, e.g., vo sundr

  13. Nr. 212 / 2010 // 8. September 2010 Knstler Eugen Jost hat die Fibonacci-Zahlenfolge in ein Bild

    E-print Network

    Dettweiler, Michael

    S. 1 / 4 Nr. 212 / 2010 // 8. September 2010 Künstler Eugen Jost hat die Fibonacci mit dem Schweizer Künstler Eugen Jost gezeigt. Aus dem gemeinsamen mathematisch-künstlerischen Projekt entstanden, die mehr als 125 000 Schüler in ganz Deutschland gesehen haben. Eugen Jost wird bei der Konferenz

  14. High-resolution LiDAR-based landslide hazard mapping and modeling, UCSF

    E-print Network

    Haneberg, William C.

    1 High-resolution LiDAR-based landslide hazard mapping and modeling, UCSF Parnassus Campus, San model (DEM) and produce landslide hazard maps of the University of California at San Francisco Parnassus and conventional topographic maps for landslide hazard mapping. The LiDAR DEM consisted of nearly 2.8 million

  15. N-16(0-) Beta-Decay and Weak Axial-Vector Meson Exchange Currents 

    E-print Network

    Gagliardi, Carl A.; Garvey, G. T.; Wrobel, J. R.; Freedman, S. J.

    1983-01-01

    . Westf?l. Wilhelms-Univ. M?n- ster i. W.?Mitteilungen aus dem Zoologischen Institut der Westf?lischen Wilhelms-Universit?t zu M?nster i. W. Mitth. Embryol. Inst. K. K. Univ. Wien.? Mittheilungen aus dem Embryologischen Institute der K. K. Universit...

  16. Sonderdruck aus Blent Ucar / Frank Griffel (Hg.)

    E-print Network

    Kallenrode, May-Britt

    Diskursen her. Von Philosophie, spekulativer Theologie, kala¯m, dem fiqh und us u¯l al-fiqh, bis hin zu der größte Muslim nach dem Propheten gewesen sei.1 Er studierte bei angesehenen Ge- lehrten wie al ausgesprochene Aversion. So bemühte er sich im Bereich der us u¯l al-fiqh die Voraussetzungen für das

  17. Geophysical Research Abstracts, Vol. 7, 09200, 2005 SRef-ID: 1607-7962/gra/EGU05-A-09200

    E-print Network

    Bolch, Tobias

    to study the glacier retreat in four selected valleys in detail. Melting of the glaciers corresponds highly Geosciences Union 2005 Glacier Retreat and Climate Change in Northern Tien Shan (Kazakhstan Landsat, ASTER data and a DEM were used to analyse the retreat of glaciers and the consequences. The DEM

  18. Volume 2 | 2010 Christian-Doppler Laboratory

    E-print Network

    Hochreiter, Sepp

    LIGGGHTS and the CFD-DEM OpenFOAM®-LIGGGHTS coupling by our lab via www.cfdem.com attracted hundreds of researchers and engineers from all over the world, from Australia to Zimbabwe. The field of DEM and CFD .................................................................................. Cyclone Separation ........................................................................ ........................................................................................... .......................................................................................... . .............................................................................. ........................................................................................... ............................................................................. ................................................................................ ............................................................. ............................................................ ............................

  19. 9/4/12 Raubtiere: Tiger bernehmen die Nachtschicht -Wissen -Tagesspiegel 1/5www.tagesspiegel.de/wissen/raubtiere-tiger-uebernehmen-die-nachtschicht-/7089876.html

    E-print Network

    9/4/12 Raubtiere: Tiger übernehmen die Nachtschicht - Wissen - Tagesspiegel 1/5www.tagesspiegel.de/wissen/raubtiere-tiger Chitwan Nationalpark. FOTO: MICHIGAN STATE UNIVERSITY Raubtiere Tiger übernehmen die Nachtschicht Menschen aus dem Weg. Das hilft ihnen, langfristig zu überleben. Tiger teilen ihr Revier mit dem Menschen

  20. 1 -1250 Messages SWAT USER GROUP

    E-print Network

    - Maximum number of outlets 44- Aster GDEM 45- DEM download 46- Reservoir vs. pond #12;5 47- Tributary 86- DEM download 87- Strange SWAT2005 Running Results 88- About water transfer 89- SWAT 2009 user NOT successful 114- SWAT 2009 installation problem with 64bit windows 7 #12;9 115- SWAT run not successful 116