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Published: 6 September 2023

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1

Löhner, Andreas. "Ein Beitrag zum Verbessern der azimutalen Auflösung vorwärtsschauender Radarsysteme mit synthetischer Apertur /." Düsseldorf : VDI-Verl, 1999. http://www.gbv.de/dms/bs/toc/300868324.pdf.

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2

Mittermayer, Josef. "Hochauflösende Verarbeitung von Radardaten mit synthetischer Apertur." Köln : Deutsches Zentrum für Luft- und Raumfahrt, Bibliotheks- und Informationswesen, 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=959894764.

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3

Scheiber, Rolf. "Hochauflösende Interferometrie für Radar mit synthetischer Apertur /." Köln : DLR, Bibliotheks- und Informationswesen, 2004. http://www.gbv.de/dms/bs/toc/392658070.pdf.

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4

Hirsch, Oliver Wolfgang. "Neue Verarbeitungsverfahren von Along-Track Interferometrie Daten eines Radars mit synthetischer Apertur." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965273024.

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5

Schütz, Martin [Verfasser]. "Systemkomponenten zur simultanen Radar-Ortung und Radar-Bildgebung mit autonomen Robotern und Fluggeräten / Martin Schütz." München : Verlag Dr. Hut, 2021. http://d-nb.info/1233525492/34.

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6

Ramminger, Gernot. "Erfassung von Sturmschäden mit Hilfe moderner Radar-Fernerkundungssystemen." [S.l. : s.n.], 2004. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB11513767.

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7

Benahmed, Daho Omar. "Radar ULB pour la vision à travers les murs : mise au point d'une chaîne de traitement de l'information d'un radar imageur." Thesis, La Rochelle, 2014. http://www.theses.fr/2014LAROS036/document.

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Nous nous intéressons dans cette thèse à la vision à travers les murs (VTM) par radar ULB, avec comme objectif la mise au point d’une chaîne de traitement de l’information (CTI) complète pouvant être utilisée par différents types de radar imageur VTM. Pour ce faire, nous souhaitons prendre en compte le moins possible d’information a priori, ni sur les cibles, ni sur leur contexte environnemental. De plus, la CTI doit répondre à des critères d’adaptabilité et de modularité pour pouvoir traiter les informations issues de deux types de radar, notamment, le pulsé et le FMCW, développés dans deux projets dans lesquels s’inscrivent les travaux de cette thèse. L’imagerie radar est un point important dans ce contexte, nous l’abordons par la combinaison des algorithmes de rétroprojection et trilatération, et montrons l’amélioration apportée avec l’utilisation d’un détecteur TFAC prenant en compte la forme des signatures des cibles. La mise au point de la CTI est notre principale contribution. Le flux d’images radar obtenu est scindé en deux parties. La première séquence dynamique contient les cibles mobiles qui sont ensuite suivies par une approche multihypothèse. La seconde séquence statique contient les cibles stationnaires ainsi que les murs intérieurs qui sont détectés par une méthode s’appuyant sur la transformée de Radon. Nous avons produit un simulateur VTM fonctionnant dans le domaine temporel et fréquentiel pour mettre au point les algorithmes de la CTI et tester leur robustesse. Plusieurs scénarios de simulation ainsi que de mesures expérimentales, montrent que la CTI construite est pertinente et robuste. Elle est ainsi validée pour les deux systèmes radar
This report is focused on Through-the-wall surveillance (TTS) using UWB radar, with the objective of developing a complete information processing pipeline (IPP) which can be used by different types of imaging radar. To do this, we want to take into account any a priori information, nor on the target, or their environmental context. In addition, the IPP must meet criteria of adaptability and modularity to process information from two types of radar, including pulsed and FMCW developed in two projects that are part of the work of this thesis. Radar imaging is an important point in this context ; we approach it by combining backprojection and trilateration algorithms and show the improvement with the use of a CFAR detector taking into account the shape of the targets signatures.The development of the IPP is our main contribution. The flow of radar images obtained is divided into two parts. The first dynamic sequence contains moving targets are tracked by a multiple hypothesis approach. The second static sequence contains stationary targets and interior walls that are highlighted by Radon transformbases approach. We developed a simulator operating in time and frequency domain to design the algorithms of the IPP and test their robustness. Several simulated scenarios and experimental measurements show that our IPP is relevant and robust. It is thus validated for both radar systems
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8

Castaings, Thibaut. "Catalogage de petits débris spatiaux en orbite basse par observations radars isolées." Phd thesis, Grenoble, 2014. http://tel.archives-ouvertes.fr/tel-00955486.

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Les débris spatiaux sont devenus une menace considérable pour la viabilité des satellites opérationnels en orbite basse. Afin de pouvoir éviter des collisions accidentelles, des systèmes de surveillance de l'espace existent mais sont limités en performances de détection pour les objets de petite taille (diamètre inférieur à 10cm), ce qui pousse à l'étude de nouvelles solutions. Cette thèse a pour objectif d'appuyer la faisabilité d'un système radar au sol utilisant un champ de veille étroit pour le catalogage de petits débris en orbite basse. Un tel système fournirait en effet des observations dites " isolées ", c'est-à-dire qu'une orbite n'est pas immédiatement déductible de chacune d'entre elles. Le grand nombre combinaisons nécessaires est alors prohibitif en termes de temps de calcul pour la résolution de ce problème de pistage. Nous proposons dans ces travaux une nouvelle méthode pour initialiser les pistes, c'est-à-dire associer des observations isolées avec une faible ambiguïté et en déduire des orbites précises. Les pistes ainsi obtenues sont combinées et filtrées grâce à un algorithme de pistage multicible que nous avons adapté aux particularités du problème. Avec un taux de couverture de plus de 80% obtenu en temps réel sur 3 jours pour des scénarios de 500 à 800 objets en plus d'un fort taux de fausses alarmes, les performances de la méthode proposée tendent à prouver la faisabilité du système envisagé. Afin d'extrapoler les résultats obtenus à de plus fortes densités d'observations, nous proposons un modèle de complexité combinatoire calibré sur les performances de l'algorithme aux faibles densités. L'apport d'un second capteur identique est également étudié et met en évidence un point de compromis entre réactivité et complexité combinatoire, ce qui offre un degré de liberté supplémentaire dans la conception d'un tel système.
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9

Araújo, Luciana Rodrigues de. "Comportamento dinâmico da região MLT tropical durante o Ciclo Solar 23." Universidade Estadual da Paraíba, 2017. http://tede.bc.uepb.edu.br/jspui/handle/tede/3117.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Wind data obtained between 1999 and 2016 from measuments by meteor radar at Cachoeira Paulista (22.7°S, 45.0°W), Brazil, were used to investigate the behavior of the dynamics on upper mesosphere and lower thermosphere region, the interannual variability in the winds, in the diurnal tide and 2-day wave amplitudes and the possible causes. The results show that zonal wind is characterized by a semiannual variation below 90 km and annual above, while the meridional wind exhibits an annual cycle at all altitudes. Monthly winds did not show quasi-biennial variation (QBO), however the seasonal winds in the zonal direction observed during the summer and fall show QBO variations type in altitudes below 90 km. The results also suggest that the zonal and meridional winds are intensified during the years of solar maximum, especially in the summer and winter seasons. The monthly amplitudes of diurnal tide show an annual variation, in which the amplitudes are greater during the eastward phase of QBO at 30 hPa. The spectrum obtained from the deseasonalized amplitudes shows a 26 months peak in the meridional component, which may to be associated with stratospheric QBO phase. The modulation of the diurnal tide amplitude by QBO shows a quasi ten-year variation, and is stronger for the solar cycle maximum. The amplitude of the 2-day wave exhibit interannual variability, however, do not shows to be affected by the QBO phase during the summer season. The amplitudes of the 2-day show interannual variability, but, only in winter it is affected by the QBO phase. Good agreement between the variation of the amplitude of the 2-day wave for meridional wind and the solar radio flux was observed for most of the summers with a significant correlation, suggesting a possible wave modulation by the 11-year solar cycle.
Dados de ventos obtidos entre 1999 e 2016 a partir de medidas por radar meteórico em Cachoeira Paulista (22,7°S, 45,0°O), Brasil, foram utilizados para investigar o comportamento da dinâmica da região da alta mesosfera e baixa termosfera, a variabilidade interanual dos ventos, das amplitudes da maré diurna e da onda de 2 dias e as possíveis causas. Os resultados mostram que o vento zonal é caracterizado por uma variação semianual abaixo de 90 km e anual acima, enquanto o vento meridional exibe um ciclo anual em todas as alturas. Os ventos mensais não mostraram variação quase bienal (QBO), contudo os ventos sazonais na direção zonal observados durante o verão e o outono mostram variações tipo QBO nas alturas abaixo de 90 km. Os resultados sugerem ainda que os ventos zonal e meridional são intensificados durante os anos de máxima atividade solar, principalmente nas estações de verão e inverno. As amplitudes mensais da maré diurna exibem variação interanual, em que as amplitudes são maiores durante a fase para leste da QBO em 30 hPa. O espectro obtido a partir das amplitudes dessazonalizadas mostra um pico próximo de 26 meses na componente meridional, o qual pode estar associado à fase da QBO estratosférica. A modulação da amplitude da maré diurna pela QBO mostra uma variação quase decenal, e é mais forte durante o máximo do ciclo solar. As amplitudes da onda de 2 dias exibem variabilidade interanual para ambas as componentes, contudo, apenas no inverno mostra ser afetada pela fase da QBO. Boa concordância entre a variação da amplitude meridional da onda de 2 dias e o fluxo de rádio solar foi observada para a maioria dos verões com correlação significativa, sugerindo uma possível modulação da onda pelo ciclo solar de 11 anos.
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10

Schmid, Hermann Wilhelm. "Hagelvorhersage mit Radar : wolkenphysikalische Untersuchungen und ein statistisches Vorhersagemodell /." [S.l.] : [s.n.], 1988. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=8684.

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11

Ramminger, Gernot. "Erfassung von Sturmschäden mit Hilfe von modernen Radar-Fernerkundungssystemen." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973169303.

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12

Dallinger, Alexander. "Zirkulares synthetisches Apertur-Radar zur Personenkontrolle mit Millimeter-Wellen." Berlin Logos, 2007. http://deposit.d-nb.de/cgi-bin/dokserv?id=3066065&prov=M&dok_var=1&dok_ext=htm.

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13

Winkler, Volker. "Automobiler Radarsensor mit integrierter Kommunikationsfunktion." Berlin Logos-Verl, 2006. http://deposit.ddb.de/cgi-bin/dokserv?id=2827573&prov=M&dok_var=1&dok_ext=htm.

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14

Reichthalhammer, Thomas [Verfasser]. "Ein Radar mit synthetischer Apertur für den Nahbereich / Thomas Reichthalhammer." München : Verlag Dr. Hut, 2012. http://d-nb.info/1022535390/34.

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15

Vasudevan, Santhosh. "HURRICANE WIND RETRIEVAL ALGORITHM DEVELOPMENT FOR AN AIRBORNE CONICAL SCANNING SCATTEROMETER." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3222.

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Reliable ocean wind vector measurements can be obtained using active microwave remote sensing (scatterometry) techniques. With the increase in the number of severe hurricanes making landfall in the United States, there is increased emphasis on operational monitoring of hurricane winds from aircraft. This thesis presents a data processing algorithm to provide real-time hurricane wind vector retrievals (wind speed and direction) from conically scanning airborne microwave scatterometer measurements of ocean surface backscatter. The algorithm is developed to best suit the specifications for the National Oceanic and Atmospheric Administration (NOAA) Hurricane Research Division's airborne scatterometer – Integrated Wind and Rain Airborne Profiler (IWRAP). Based on previous scatterometer wind retrieval methodologies, the main focus of the work is to achieve rapid data processing to provide real-time measurements to the NOAA Hurricane Center. A detailed description is presented of special techniques used. Because IWRAP flight data were not available at the time of this development, the wind retrieval performance was evaluated using a Monte Carlo simulation, whereby radar backscatter measurements were simulated with instrument and geophysical noise and then used to infer the surface wind conditions in a simulated (numerical weather model) hurricane wind field
M.S.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering
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16

Vagnoni, Cristina. "Algorithms for the computation of the joint spectral radius." Doctoral thesis, Università degli studi di Padova, 2008. http://hdl.handle.net/11577/3425106.

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The asymptotic behaviour of the solutions of a discrete linear dynamical system is related to the spectral radius R of its associated family F. In particular, a system is stable if R <= 1 and there exists an extremal norm for the family F. This kind of systems is important for a large number of applications. In particular, we mention the stability analysis of numerical methods for ordinary differential equations. In the last decades some algorithms have been proposed in order to find real extremal norms of polytope type in the case of finite families (see for example [BT79] and [GZ05]). However, recently it has been observed that it is more useful to consider complex polytope norms, which are norms whose unit ball is a balanced complex polytope (see for example [GWZ05] and [MiSa06]). In this work, using the theory developed in [GZ07], we extend the algorithm for the construction (i.e. for the geometric representation) of the unit ball of real polytope norms to the complex space. In order to succeed in our purpose, we first needed to get a deeper theoretical knowledge of the balanced complex polytopes. However, due to the extreme increase in complexity of the geometry of such objects with the dimension n of the space, we have confined ourselves to face the two-dimensional case. In particular, we have given original theoretical results on the geometry of two-dimensional balanced complex polytopes in order to present the first two efficient algorithms, one for the construction of a balanced complex polytope in the two-dimensional space and one for the computation of the complex polytope norm of a two-dimensional vector starting from the knowledge of the boundary of the corresponding unit ball.
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17

Keil, Christian. "Numerische Simulation von Starkniederschlagsereignissen mit mesoskaligen Wettervorhersagemodellen : Überprüfung mit Radar-Daten und Diagnose der atmosphärischen Wasserbilanz /." Köln : Deutsches Zentrum für Luft- und Raumfahrt, Bibliotheks- und Informationswesen, 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=960293620.

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18

Bauer-Pfundstein, Matthias [Verfasser]. "Bestimmung von Turbulenzparametern und der Schallabsorption mit einem Wind-Temperatur-RADAR / Matthias Bauer-Pfundstein." Karlsruhe : KIT-Bibliothek, 1999. http://d-nb.info/1198223731/34.

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19

Blahak, Ulrich. "Analyse des Extinktionseffektes bei Niederschlagsmessungen mit einem C-Band-Radar anhand von Simulation und Messung /." Karlsruhe : Institut für Meteorologie und Klimaforschung Universität Karlsruhe (TH), 2005. http://swbplus.bsz-bw.de/bsz116418370abs.htm.

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20

Bachmann, Timo. "Osteometische Typisierung des Radius von rezenten Mitteleuropäern mit Hilfe künstlicher neuronaler Netze." Aachen Mainz, 2009. http://d-nb.info/1000339610/04.

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21

Sturm, Christian [Verfasser], and T. [Akademischer Betreuer] Zwick. "Gemeinsame Realisierung von Radar-Sensorik und Funkkommunikation mit OFDM-Signalen / Christian Andreas Sturm ; Betreuer: T. Zwick." Karlsruhe : KIT Scientific Publishing, 2012. http://d-nb.info/1184492646/34.

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22

Wendrich, Astrid [Verfasser], and Kurt [Akademischer Betreuer] Kießl. "Zerstörungsfreie Ortung von Anomalien in historischem Mauerwerk mit Radar und Ultraschall / Astrid Wendrich ; Betreuer: Kurt Kießl." Weimar : Professur Bauklimatik, 2009. http://d-nb.info/1115342061/34.

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23

Nasonova, Sasha. "Estimating Arctic sea ice melt pond fraction and assessing ice type separability during advanced melt." Thesis, Remote Sensing, 2017. https://dspace.library.uvic.ca//handle/1828/9313.

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Arctic sea ice is rapidly declining in extent, thickness, volume and age, with the majority of the decline in extent observed at the end of the melt season. Advanced melt is a thermodynamic regime and is characterized by the formation of melt ponds on the sea ice surface, which have a lower surface albedo (0.2-0.4) than the surrounding ice (0.5-0.7) allowing more shortwave radiation to enter the system. The loss of multiyear ice (MYI) may have a profound impact on the energy balance of the system because melt ponds on first-year ice (FYI) comprise up to 70% of the ice surface during advanced melt, compared to 40% on MYI. Despite the importance of advanced melt to the ocean-sea ice-atmosphere system, advanced melt and the extent to which winter conditions influence it remain poorly understood due to the highly dynamic nature of melt pond formation and evolution, and a lack of reliable observations during this time. In order to establish quantitative links between winter and subsequent advanced melt conditions, and assess the effects of scale and choice of aggregation features on the relationships, three data aggregation approaches at varied spatial scales were used to compare high resolution satellite GeoEye-1 optical images of melt pond covered sea ice to winter airborne laser scanner surface roughness and electromagnetic induction sea ice thickness measurements. The findings indicate that winter sea ice thickness has a strong association with melt pond fraction (fp) for FYI and MYI. FYI winter surface roughness is correlated with fp, whereas for MYI no association with fp was found. Satellite-borne synthetic aperture radar (SAR) data are heavily relied upon for sea ice observation; however, during advanced melt the reliability of observations is reduced. In preparation for the upcoming launch of the RADARSAT Constellation Mission (RCM), the Kolmogorov-Smirnov (KS) statistical test was used to assess the ability of simulated RCM parameters and grey level co-occurrence matrix (GLCM) derived texture features to discriminate between major ice types during winter and advanced melt, with a focus on advanced melt. RCM parameters with highest discrimination ability in conjunction with optimal GLCM texture features were used as input parameters for Support Vector Machine (SVM) supervised classifications. The results indicate that steep incidence angle RCM parameters show promise for distinguishing between FYI and MYI during advanced melt with an overall classification accuracy of 77.06%. The addition of GLCM texture parameters improved accuracy to 85.91%. This thesis provides valuable contributions to the growing body of literature on fp parameterization and SAR ice type discrimination during advanced melt.
Graduate
2019-03-21
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24

Kristin, Julia. "Vorhersagekraft der Versagenslast des distalen Radius mit Mikro-Computertomographie und Zweienergie-Röntgen-Absorptiometrie." Diss., lmu, 2007. http://nbn-resolving.de/urn:nbn:de:bvb:19-75895.

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25

Preko, Kwasi. "Determination of Volumetric Soil Water Content Using Ground Penetrating Radar Bestimmung des volumetrischen Bodenwassergehaltes mit dem Bodenradar /." [S.l. : s.n.], 2007. http://digbib.ubka.uni-karlsruhe.de/volltexte/1000007396.

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26

Dean, Andrew Mark. "Vegetation, topography and snow melt at the Forest-Tundra Ecotone in arctic Europe : a study using synthetic aperture radar." Thesis, Durham University, 2003. http://etheses.dur.ac.uk/4037/.

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This research was conducted as part of DART (Dynamic Response of the Forest-Tundra Ecotone to Environmental Change), a four year (1998-2002) European Commission funded international programme of research addressing the potential dynamic response of the (mountain birch) forest-tundra ecotone to environmental change. Satellite remote sensing was used to map landscape scale (lO(^1)-lO(^3) m) patterns of vegetation and spatial dynamics of snow melt at the forest-tundra ecotone at three sites along ca. an 8º latitudinal gradient in the Fermoscandian mountain range. Vegetation at the forest-tundra ecotone was mapped using visible -near infrared (VIR) satellite imagery, with class definition dependent on the timing of the acquisition of imagery (related to highly dynamic vegetation phenology) and spatial variation in the FTE. Multi-temporal spacebome ERS-2 synthetic aperture radar (SAR) was used for mapping snow melt. Comprehensive field measurements of snow properties and meteorological data combined with a physically based snow backscatter model indicated potential for mapping wet snow cover at each site. Significant temporal backscatter signatures enabled a classification algorithm to be developed to map the pattern of snow melt across the forest- tundra ecotone. However, diurnal and seasonal melt-freeze effects relative to the timing of ERS-2 SAR image acquisition effectively reduce the temporal resolution of data. Further, the study sites with large topographic variation and complex vegetative cover, provided a challenging operating environment and problems were identified with the robustness of classification during the later stages of snow melt because of the effects of vegetation. Significant associations were identified between vegetation, topography, and snow melt despite limitations in the snow mapping.
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27

Pandolfi, Carlo. "Studio preliminare di un sistema di monitoraggio e controllo del traffico di superficie nell’area di manovra dell’aeroporto di Fiumicino." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2013. http://amslaurea.unibo.it/4850/.

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Questo lavoro ha analizzato il modulo di localizzazione ed identificazione dei mezzi circolanti in area di manovra e la tecnologia da impiegare per ottenere lo scambio dei dati tra le unità imbarcate ed il server centrale. L’attività è stata svolta in collaborazione con ADR-Aeroporti di Roma, gestore aeroportuale di Fiumicino. L’obiettivo è quello di ottenere, in tempo reale, la conoscenza della posizione e della traiettoria di tutti i mezzi circolanti in area di manovra per creare un sistema automatizzato di monitoraggio, in grado di controllare sia eventuali invasioni delle piste e dei raccordi principali sia rischi di potenziali collisioni tra velivoli e mezzi, garantendo la minima separazione richiesta dalle normative e fornendo agli operatori l’indicazione del rischio rilevato. La prima parte della tesi espone lo scenario europeo per quanto riguarda le tecnologie utilizzate per la sorveglianza di velivoli in area di manovra, la seconda descrive la tecnologia più diffusa e promettente a livello internazionale, proposta per l’aeroporto di Fiumicino, mentre nella terza parte tale tecnologia viene analizzata e sviluppata appunto per lo scenario preso in considerazione.
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28

Anke, Juliane, Angela Francke, and Tibor Petzoldt. "RadVerS - Mit Smartphones generierte Verhaltensdaten im Verkehr – Differenzierung des Nutzerverhaltens unterschiedlicher RadfahrerInnengruppen : Teil I: Typologisierung von RadfahrerInnen." Technische Universität Dresden, 2021. https://publish.fid-move.qucosa.de/id/qucosa%3A76000.

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Ziel der vorliegenden Studie war es, eine Typologie von RadfahrerInnen in Deutschland zu erarbeiten und diese zu beschreiben. Zu diesem Zweck wurde auf Basis einer umfassenden Literaturrecherche eine groß angelegte Online-Befragung vom 20.11.2017 bis 07.01.2018 durchgeführt. Insgesamt wurden dabei 10.294 auswertbare Datensätze gewonnen. Durch Hauptkomponenten- und Faktorenanalyse wurden neun Faktoren (symbolische Motive, affektive Motive, instrumentelle Motive, subjektive Sicherheit, Identifikation als RadfahrerIn, zeitliche Distanz, Nutzungshäufigkeit, Wetter/Komfort und Regeltreue) extrahiert, die anschließend zur Clusterung der RadfahrerInnen genutzt wurden. Mit Hilfe dieser Faktoren ließen sich vier Typen von RadfahrerInnen identifizieren: passionierter, pragmatischer, funktioneller und ambitionierter Radfahrtyp. Die Typen unterscheiden sich dabei sowohl hinsichtlich der Typologisierungsfaktoren als auch bezüglich infrastruktureller Präferenzen, Unfallhistorie und der Radfahrhäufigkeit für bestimmte Wegezwecke. Die Einbeziehung motivationaler Faktoren erbrachte wichtige Einblicke in die Eigenschaften von RadfahrerInnen. Für den passionierten Radfahrtyp spielen sowohl Faktoren, wie die soziale Anerkennung bzw. Identifikation mit dem Umfeld, die Freude am Fahren als auch Faktoren wie Flexibilität oder Umweltschutz eine wichtige Rolle. Der Pragmatische wird dagegen v.a. instrumentell motiviert, d.h. das Rad wird genutzt, weil es flexibel ist, gut für die eigene Fitness und man damit schnell vorankommt. Insgesamt am wenigsten zum Radfahren motiviert ist der/die funktionelle RadfahrerIn. Für diesen Typ stehen z.B. ökonomische Gründe bei der Radnutzung im Vordergrund und das Fahrrad wird eher als „Mittel zum Zweck“ gesehen. Der Spaß am Fahren sowie die Zugehörigkeit zu oder das Kennenlernen von Personen sind für die ambitionierten RadfahrerInnen Hauptmotive für die Radnutzung. Aus den Kenntnissen der Eigenschaften der vier Radfahrtypen lassen sich u.a. Implikationen für die Radverkehrsförderung ableiten. So könnten z.B. Kampagnen vermitteln, dass das Fahrrad mehr sein kann als nur „Mittel zum Zweck“, um funktionelle und pragmatische Typen zu einer (Mehr-) Nutzung zu ermutigen. Die Arbeit schließt mit einem Ausblick auf Teil 2 des Projektes, bei dem die gewonnenen Erkenntnisse über die Radfahrtypen mit realem Fahrverhalten verknüpft wurden.
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Wagner, Beatrix, Monika Pilarski, Andreas Forgber, and Martin Wagner. "Der Einsatz von Fernerkundungstechnologien im Kontext mit dem Markscheidewesen und der Geotechnik - Beispiele aus der Praxis." Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2016. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-206127.

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In diesem Beitrag wird aufgezeigt, wie die Firma ILV durch langjährige Beteiligung an Forschungs- und Entwicklungsvorhaben sowie durch Industrieerprobung von innovativen Technologien erfolgreich im In- und Ausland arbeitet. Vorgestellt werden schwerpunkthaft Ergebnisse der Anwendung von Satellitenbilddaten im visuellen Bereich und von Radardaten sowie Erfahrungen bei der Einführung der digitalen Luftbildkameratechnik. Berichte aus der Praxis des digitalen Bildfluges im Ausland auch aus Sicht des Auftraggebers für geologische und geotechnische Fragestellungen und der Industrieerprobung von Multibeam-Sonar-Technik zeigen die innovativen Potentiale dieser Technologien
In this paper, it is shown how the company ILV works successfully domestically and abroad by long standing involvement in research and development projects as well as by industrial testing of innovative technologies. The focus of the paper are results of application of satellite images in visual range and of radar data as experiences with the introduction of digital airborne camera technique. Field notes about digital photo flight abroad – also from the view of the customer for geological and geotechnical problems – and about industrial testing of Multi-beam Sonar Technique show the innovative potentials of these technologies
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Vollbracht, Dennis. "Design and development of phased-array antennas for dual-polarized weather radar applications." Universitätsverlag Chemnitz, 2017. https://monarch.qucosa.de/id/qucosa%3A32005.

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Phased array weather radar antennas with beam steering capabilities are suitable alternatives to weather radars with mechanically scanning reflector antennas. Dual-polarized phased-array weather radar antennas, however, demand careful assessment of the x-polar characteristics. The low x-pol radiation of polarimetric weather radar antennas is of significant importance for the proper classification and qualitative estimation of hydrometeors in illuminate volumes. Unfortunately, array antennas display changing x-pol contributions during the electronical beam steering process. Typically, the x-pol radiation will be substantially increased in the co-polar main beam direction but also in other angular directions. Consequently, it is a vital challenge to design arrays with low x-pol contribution during beam steering. In this dissertation a new phased-array weather radar concept is developed. The phased array system configuration can be used to substitute state-of-the-art weather radars with reflector antennas. Furthermore, a dense network of these phased-array radars can be used to substitute a network of high power weather radars, which are used nowadays. The research focus of this work is the development of a dual-polarized microstrip patch antenna with phased-array capability and very high polarization purity. In this regard, new graphical techniques are developed to investigate the causes and the reduction of the x-pol radiation of isolated (stand-alone) microstrip patch antennas. To further reduce the x-pol contribution of antennas, optimization methods have been investigated, evaluated and developed. For the first time in literature, differential-feed antenna arrays are compared to excitation optimized single-feed antenna arrays in their x-pol contribution in the boresight direction and during beam steering. In particular, two dual-polarized 4x8 antenna arrays have been developed and simulated by CST MWS, produced as multilayer PCB and verified at the compact antenna test range at RWTH Aachen. The results show that the x-pol contributions of arrays are significantly reduced for differentially-feed antenna arrays, even when beam steering is performed. During the azimuth scan of 120_ a record setting x-pol suppression of -45 dB and -36 dB could be measured for the horizontal and vertical polarization channels, respectively.
Wetterradarsysteme mit phasengesteuerten Antennen stellen eine echte Alternative zu Wetterradarsystemen mit mechanisch drehenden Reflektorantennen dar. Dual-polarisierte phasengesteuerte Antennen müssen jedoch sehr genau in ihrem Kreuzpolarisationsverhalten verifiziert werden, um für den Wetterradarbereich von Nutzen zu sein. Die Unterdrückung der kreuzpolaren Anteile von Radarantennen ist von fundamentaler Bedeutung, um Hydrometeore mit Hilfe von polarimetrischen Wetterradarsystemen klassifizieren und qualitativ bestimmen zu können. Die hohe Anforderung an Polarisationsreinheit ist mit aktuell erhältlichen Arraydesigns nur schwierig zu realisieren, da sich die Kreuzpolarisationsunterdrückung während des elektronischen Schwenks der Hauptkeule signifikant verschlechtert. Diese Dissertation stellt ein Wetterradar Systemkonzept mit phasengesteuerter Gruppenantenne vor, welches die aktuell genutzten Wetterradare mit Reflektorantennen ablösen könnte. Der Fokus der Arbeit wurde auf die Entwicklung einer Dual-polarimetrischen, polarisationsreinen und phasengesteuerten Mikrostreifenleiterantennen gelegt. Hierbei wurden neue grafische Verfahren entwickelt, die es ermöglichen, die Generierung der kreuzpolaren Anteile von isolierten Patchantennen (Einzelpatche) zu erklären und zu minimieren. Um die kreuzpolaren Anteile weiter herabzusetzen wurden Optimierungsverfahren für Arrayantennen erforscht, bewertet und neu entwickelt. Zum ersten Mal wurden differentiell gespeiste mit einzeln gespeisten Antennenarrays in ihrem Kreuzpolarisationsverhalten während des elektronischen Schwenks der Hauptkeule verglichen. Zwei Dual- polarimetrische 4x8 Antennenarrays (differentiell gespeist und mit optimierter Phasenansteuerung) wurden zu diesem Zweck mittels CST MWS entworfen, simuliert, als Multilagenplatine gefertigt und an der Antennentestanlage der RWTH Aachen vermessen. Die Resultate zeigen, dass die Kreuzpolarisationsanteile bei differentiell gespeisten Mikrostreifenleiterantennen in Gruppenkonfiguration, selbst beim elektronischen Schwenk der Hauptkeule, signifikant minimiert werden konnten. Für einen azimutalen Scanbereich von 120_ konnte eine exzellente Kreuzpolarisationsunterdrückung zwischen -45 dB und -36 dB messtechnisch für den horizontalen und vertikalen Polarisationskanal nachgewiesen werden.
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Göbell, Sibylle. "Determination of sea ice surface elevation with laser and radar altimetry and comparison with ice thickness data sets in the Arctic and Antarctic = Bestimmung der Oberflächenhöhe von Meereis mit Laser- und Radaraltimetrie und Vergleich mit Eisdickendatensätzen in der Arktis und Antarktis /." Bremerhaven : Alfred-Wegener-Institut für Polar- und Meeresforschung, 2007. http://www.loc.gov/catdir/toc/fy0803/2008365359.html.

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Wendrich, Astrid [Verfasser], Kurt [Gutachter] Kießl, Werner [Gutachter] Leschnik, and Jens [Gutachter] Tronicke. "Zerstörungsfreie Ortung von Anomalien in historischem Mauerwerk mit Radar und Ultraschall - Möglichkeiten und Grenzen - / Astrid Wendrich ; Gutachter: Kurt Kießl, Werner Leschnik, Jens Tronicke." Berlin : Bundesanstalt für Materialforschung und -prüfung (BAM), 2009. http://d-nb.info/1122835787/34.

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33

Rösch, Kerstin [Verfasser]. "Retrospektive Analyse diaphysärer und distal metaphysärer Radius/Ulna-Frakturen beim Hund nach Plattenosteosynthese und Osteosynthese mit Fixateur externe / Kerstin Rösch." Berlin : Freie Universität Berlin, 2021. http://d-nb.info/1233986821/34.

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34

Lorenzen, Thore [Verfasser], and Andreas [Akademischer Betreuer] Plettenberg. "Therapieumstellungen bei antiretroviral vorbehandelten HIV-infizierten Patienten mit Hilfe des Expertenrat-Systems Radata Analyse des Therapieverlaufes / Thore Lorenzen. Betreuer: Andreas Plettenberg." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2012. http://d-nb.info/103036592X/34.

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Lorenzen, Thore Verfasser], and Andreas [Akademischer Betreuer] [Plettenberg. "Therapieumstellungen bei antiretroviral vorbehandelten HIV-infizierten Patienten mit Hilfe des Expertenrat-Systems Radata Analyse des Therapieverlaufes / Thore Lorenzen. Betreuer: Andreas Plettenberg." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2012. http://d-nb.info/103036592X/34.

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36

Phruksahiran, Narathep. "Polarimetrische Streuungseigenschaften und Fokussierungsmethoden zur quantitativen Auswertung der polarimetrischen SAR-Daten." Doctoral thesis, Universitätsbibliothek Chemnitz, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-107764.

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Das Radar mit synthetischer Apertur (Synthetic Aperture Radar - SAR) liefert eine quasi-fotographische Abbildung der beleuchteten Bodenoberfläche mit zusätzlichen Informationen, die von der gesendeten und empfangenen Polarisation der Wellen abhängig sind. Eine nützliche Anwendung der polarimetrischen SAR-Daten liegt bei der Klassifizierung der Bodenstruktur anhand der polarimetrischen Streuungseigenschaften. In diesem Zusammenhang beschäftigt sich die vorliegende Arbeit mit der Entwicklung und Untersuchung neuer polarimetrischen Fokussierungsfunktion für die SAR-Datenverarbeitung mit Hilfe der polarimetrischen Rückstreuungseigenschaft, die zu einer alternativen quantitativen Auswertung der polarimerischen SAR-Daten führen kann. Die physikalische Optik Approximation wird für die numerische Berechnung der rückgestreuten elektrischen Felder der kanonischen Ziele unter SAR-Geometrie unter Berücksichtigung der Polarisationslage verwendet. Aus den rückgestreuten elektrischen Felder werden die polarimetrischen Radarrückstreuquerschnitte berechnet. Ein SAR-Simulator wird zur Datenverarbeitung der E-SAR des DLR entwickelt. Der Ansatz des polarimetrischen Radarrückstreuquerschnittes ermöglicht die approximierte numerische Berechnung der Rückstreuungseigenschaften der kanonischen Ziele sowohl im kopolaren als auch im kreuzpolaren Polarisationsbetrieb. Bei der SAR-Datenverarbeitung werden die Rohdatensätze durch die Referenzfunktion eines Punktzieles in der Entfernungsrichtung verarbeitet. Bei der Azimutkompression werden die vier Referenzfunktionen, das heißt die Referenzfunktion eines Punktzieles, die polarimetrische Fokussierungsfunktion einer flachen Platte, die polarimetrische Fokussierungsfunktion eines Zweifach-Reflektors und die polarimetrische Fokussierungsfunktion eines Dreifach-Reflektors, eingesetzt. Die qunatitativen Auswertung der SAR-Daten werden anhand des Pauli-Zerlegungstheorems, der differentiellen Reflektivität und des linearen Depolarisationsverhältnises durchgeführt.
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Kunz, Lukas Brad. "A New Method for Melt Detection on Antarctic Ice-Shelves and Scatterometer Calibration Verification." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd527.pdf.

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Schulz-Wackerbarth, Cyriak Nathanael [Verfasser]. "Evaluation der Spaltlampen Spectral Radar Optischen Kohärenztomographie (SL SR OCT) und Vergleich mit SL OCT und Stratus OCT bei physiologischen und pathologischen Befunden des vorderen und hinteren Augenabschnittes / Cyriak Nathanael Schulz-Wackerbarth." Lübeck : Zentrale Hochschulbibliothek Lübeck, 2011. http://d-nb.info/1018316558/34.

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39

Dütsch, Yvonne [Verfasser], Jan S. [Akademischer Betreuer] Bauer, Rothe Rüdiger von [Akademischer Betreuer] Eisenhart, and Simone [Akademischer Betreuer] Waldt. "Reproduzierbarkeit trabekulärer Strukturparameter des distalen Radius akquiriert mit hochauflösender Magnetresonanztomographie bei 1,5 und 3,0 Tesla / Yvonne Dütsch. Gutachter: Rüdiger von Eisenhart-Rothe ; Simone Waldt. Betreuer: Jan S. Bauer." München : Universitätsbibliothek der TU München, 2013. http://d-nb.info/1046404725/34.

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40

Stracke, Siegbert. "Laser-Doppler-Flowmetrie bei Osteoporose : eine Untersuchung der Durchblutung des distalen Radius im Übergangsbereich von Periost zu Knochen mit Hilfe der Laser-Doppler-Flowmetrie zur Erfassung funktioneller Parameter der Mikrozirkulation /." Giessen : VVB Laufersweiler, 2007. http://d-nb.info/988006715/04.

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Stracke, Siegbert [Verfasser]. "Laser-Doppler-Flowmetrie bei Osteoporose : eine Untersuchung der Durchblutung des distalen Radius im Übergangsbereich von Periost zu Knochen mit Hilfe der Laser-Doppler-Flowmetrie zur Erfassung funktioneller Parameter der Mikrozirkulation / vorgelegt von Siegbert Stracke." Giessen : VVB Laufersweiler, 2008. http://d-nb.info/988772051/34.

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42

Novotná, Eliška. "Porovnání české společnosti s ručením omezeným a jejího založení a vzniku s Gesellschaft mit beschrankten Haftung (GmbH) v SRN." Master's thesis, Vysoká škola ekonomická v Praze, 2011. http://www.nusl.cz/ntk/nusl-114227.

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This master dissertation is dedicated to the main characteristics and to the process of establishment of Private Limited Company in the Czech Republic and Germany and to the comparison of these two national legal forms. The goal of this work is to compare Czech and German Ltd. in a very clear way, so the reader can understand what the differences of this type of company in the national legal forms mentioned above are and what have on the contrary in common. The work deals also with the Czech and German Ltd. in separated chapters in order to be the comparison for the reader comprehensible. In the end of the master dissertation is expressed the author's opinion, which national legal form of this type of company is better and in what way.
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Spargo, Andrew John. "Studies of the MLT/I using Multistatic Meteor Radar." Thesis, 2021. http://hdl.handle.net/2440/130751.

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This thesis applies a multistatic meteor radar to an investigation of the dynamics of the mesosphere lower thermosphere/ionosphere (MLT/I; 60-110 km altitude). The main radar used in the study operates at 55 MHz and is in the vicinity of Adelaide, South Australia, consisting of a monostatic radar at the Buckland Park eld site (34.6 S, 138.5 E) and a bistatic receiver located about 55 km south-east at a site in the Adelaide Hills (35.1 S, 138.8 E). The areas of investigation pertaining to MLT/I dynamics include assessing the ability of a multistatic meteor radar to measure the vertical ux of horizontal momentum and studying the interaction between gravity waves and tidal e ects. The thesis also presents a novel phase calibration technique for meteor radars, based on the use of civilian aircraft. The assessment of this radar's ability to measure MLT/I momentum uxes demonstrated that a relative uncertainty of about 75% can be expected for a monostatic con guration, assuming a ux magnitude of 20 m2s-2, a single day of integration, and a gravity wave field synthesized from a realistic spectral model. The multistatic configuration with a single bistatic receiver is shown to yield a relative uncertainty of about 65% under the same conditions. It is suggested that the increase in precision can be attributed entirely to the increase in the number of meteor detections associated with the combined monostatic and bistatic receivers, rather than due to the existence of a more favourable distribution of Bragg vectors arising from the receiver separation. A case study of winds around the autumnal equinox of 2018 revealed large modulations in diurnal tidal amplitudes, with peak component diurnal tide amplitudes of 50 ms-1 and peak zonal wind velocities of 140 ms-1. In the context of the need to verify the accuracy of momentum ux estimates from the radar, this motivated an investigation into the role momentum transport from gravity wave breaking played in modulating the tidal amplitudes. The investigation showed that while the observed gravity wave forcing exhibited a complex relationship with the tidal winds, the components of the forcing were generally seen to be approximately out of phase with the tidal winds above altitudes of 88 km. Additionally, no clear phase relationship between the tides and gravity wave forcing was observed below 88 km. Following the case study, the altitude and angle-of-arrival (AOA) errors and reduced meteor detection rates associated with suspected receiver phase calibration errors motivated the development of an alternative phase calibration technique. The technique developed was based on the use of echoes from civilian aircraft with known positions. Approximately two weeks worth of aircraft detections with the radar and a 1090 MHz Automatic Dependent Surveillance Broadcast receiver (used to receive aircraft position information) was acquired during November 2019. By taking into account the implied phase correction variability with AOA using a beamforming approach, it was shown that the aircraft-based corrections yielded an equal or smaller meteor height distribution width than the conventionally used empirical phase calibration technique. Assuming that a smaller height distribution width equates to smaller average height estimation errors, this was taken to mean that the aircraft-based approach outperformed the empirical one.
Thesis (Ph.D.) -- University of Adelaide, School of Physical Sciences, 2021
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Zaman, Zahra. "Stimulation eines Radar-Objekterkennungs- und Trackingverfahren mit synthetischen Daten." Master's thesis, 2020. https://tuprints.ulb.tu-darmstadt.de/13502/1/math_761-19_zahra_zaman_ho_tuprints.pdf.

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Obwohl heute noch keine automatisierten Fahrzeuge flächendeckend im Straßenverkehr zu finden sind, werden moderne Fahrzeuge vermehrt mit Fahrerassistenzsystemen ausgestattet, um bereits so eine Steigerung der Sicherheit, aber auch des Komforts zu erreichen. Bis zu seiner Einführung trifft das automatisierte Fahren auf Hürden, welche insbesondere die Freigabe der automatisierten Fahrzeuge betreffen. Die Freigabe benötigt, ebenfalls zur Absicherung der Automobilhersteller, einen umfassenden Sicherheitsnachweis. Dieser Nachweis erfordert Feldversuche und deren anschließen- den Auswertung, sodass Aussagen zum Sicherheitspotenzial einer automatisierten Fahrt getroffen werden können. Um den Aufwand der Realfahrten, welcher durch Feldversuche verursacht wird, zu senken, wird ein Teil der Realfahrten durch Sicherheitsnachweise in Simulationsumgebungen ersetzt. Diese Simulationsumgebungen bilden nicht nur das Fahrzeug und die Umgebung virtuell ab, sondern modellieren auch die erforderlichen Sensoren. Aus diesem Grund wurde am Fachgebiet für Fahrzeugtechnik an der Technischen Universität Darmstadt ein Radarsensormodell entwickelt und in der Simulationssoftware Virtual Test Drive von Vires implementiert. Dieses Modell erzeugt mithilfe eines Raytracing-Verfahrens synthetische Rohdaten und extrahiert hieraus einzelne Detektionen. Die zeitliche Nachverfolgung dieser Einzeldetektionen, dem sogenannten Tracking, ermöglicht, Detektionen zu Objekten zusammenzufassen. Beim FZD steht der Radarsensor eines Automobilzulieferers zur Verfügung, welcher allerdings keinen Einblick in die genaue Funktionsweise des Tracking-Moduls erlaubt, sodass eine Anpassung dieses Moduls zur zusätzlichen Verarbeitung von synthetischen Rohdaten nicht möglich ist. Ziel dieser Masterthesis ist es daher, einen Algorithmus zur Radar-Objekterkennung und Tracking zu implementieren, welcher in der Lage ist sowohl Mess- als auch Simulationsdaten derart zu verarbeiten, dass eine Objektliste ausgegeben wird.
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Swart, Petrus Hermanus. "Elektromagnetiese pulskompressie met behulp van versadigbare magnetiese kerne." Thesis, 2015. http://hdl.handle.net/10210/13383.

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M.Ing.
Pulse Compression is a technique that may be employed for the generation of extremely high amplitude current and voltage pulses. These pulses can be as short as 50 to 100 ns, and may have amplitudes in the kiloampere and kilovolt ranges. Pulse Compression entails the compression of relatively "flat" pulses in the time domain, to pulses of very high amplitudes and extremely short duration. The pulse amplitudes and durations necessary to be achieved in this research, lie in the range where the switching speeds and other parameters of semiconductors are inadequate and where even the working life of conventional gas discharge apparatus are drastically reduced by the extreme switching demands. The burden of excessively high current densities and unmanageable current rise-rates can be transferred from the semiconductor switches to electromagnetic switches, by making use of pulse compression. Pulse compression can be carried out simultaneously or separately for the compression of the current or voltage content of pulses derived from slowly switched sources, to obtain pulses of extremely short duration and very high amplitudes. The main theme of this dissertation is Current compression. Current compression is accomplished through series-resonance in capacitors and saturable inductors connected in a transmission-line configuration. Energy is transferred in this process from one stage to the next, with reduction in pulse-time in each successive stage and a commensurate increase in amplitude. The generated pulses can attain gigawatt amplitudes and nanosecond durations, whilst loading on the semiconducting switches remains low. In addition to design of the pulse-compressor proper, the work also includes design and development of a voltage-controlled pulse power supply, suitable for generating the initial pulses which are to be compressed. Multistage pulse compression is based on the non-linear characteristics of saturable inductors. Dynamic analogue-time simulation is indispensable in a study thereof, as new theory has to be validated and because non-linear analysis is complex and capable only of being executed by employing approximation methods. Because of the difficulties involved, a considerable amount of attention has been devoted to the development of suitable analogue-dynamic simulation programs for execution on a digital computer. A numerical technique has been developed to express non-linear parameters in differential form. This technique makes it possible to model and simulate virtually any non-linear, physically realizable lumped parameter system with ease. The program is based on State Space techniques and has been developed for its versatility, to accomplish the simulation of a wide variety of circuit configurations.
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Hirsch, Oliver Wolfgang [Verfasser]. "Neue Verarbeitungsverfahren von Along-Track Interferometrie Daten eines Radars mit synthetischer Apertur / von Oliver Wolfgang Hirsch." 2002. http://d-nb.info/965273024/34.

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Ramminger, Gernot [Verfasser]. "Erfassung von Sturmschäden mit Hilfe von modernen Radar-Fernerkundungssystemen / vorgelegt von Gernot Ramminger." 2004. http://d-nb.info/973169303/34.

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48

Keil, Christian [Verfasser]. "Numerische Simulation von Starkniederschlagsereignissen mit mesoskaligen Wettervorhersagemodellen : Überprüfung mit Radar-Daten und Diagnose der atmosphärischen Wasserbilanz / Christian Keil." 2000. http://d-nb.info/960293620/34.

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Manuel, João Carlos dos Santos. "Estudo do movimento de glaciares na Antartida com interferometria radar de abertura sintética." Master's thesis, 2013. http://hdl.handle.net/10451/10270.

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Tese de mestrado em Engenharia Geográfica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2013
O estudo da deformação de glaciares e da avaliação do derretimento dos glaciares é importante para a avaliação do impacto que os glaciares têm nas mudanças climáticas. O estudo em regiões inóspitas como a Antártida é limitado, devido ao difícil acesso que apresenta. No entanto, a Antártida é das regiões mais importantes para o estudo da deformação glaciar, pois contém importantes indicadores das mudanças climáticas. Técnicas de detecção remota, como a interferometria SAR (InSAR), facilitam este tipo de estudos. O trabalho realizado na presente dissertação consistiu em desenvolver um estudo da deformação do terreno (gelo e glaciares) em zonas consideradas inóspitas, através de interferometria diferencial SAR (DInSAR). A área em estudo corresponde à Ilha Livingston, Ilha Deception e Ilha Snow. Foi ainda realizado um segundo objectivo que consiste na criação de modelos digitais de terreno (MDT), para efeitos de criação de produtos cartográficos. Serão criados dois MDTs que cobrirão as Ilhas Livingston, Deception e Snow, e a Ilha King George, respectivamente. Para o desenvolvimento dos dois objectivos, são realizadas, então, técnicas de processamento automáticas em imagens satélite que englobam a região Antes da realização do processamento de interferometria SAR, foi gerado um MDT de referência, com uma resolução de 90 m, através da combinação de um MDT, extraído através de curvas de níveis geradas a partir de cartas da região, e um MDT fornecido pela National Snow and Ice Data Center (NSIDC). Este MDT de referência irá ter um papel importante, mais tarde, no estudo da deformação do terreno, para utilização no processamento das imagens, e para comparação com os modelos digitais de terrenos criados. O processo InSAR consiste, então, na realização das técnicas de processamento em duas imagens satélite, da mesma zona. O produto que sairá da realização dessas técnicas consistirá num interferograma. Uma vez obtido este produto, tem-se que para o estudo da deformação (técnica DInSAR), é realizada a subtracção automática do MDT de referência com o interferograma, gerando um interferograma diferencial. Este interferograma diferencial respresenta a deformação do terreno. No estudo de deformação, foram processados 14 interferogramas, compreendidos entre os períodos de 1993 e 2000. A análise efectuada é dividida por três trajectos, e dentro desses trajectos em várias regiões. Esta análise é realizada de uma forma subjectiva, ou seja, através da contagem do padrão de franjas nos interferogramas, e assumindo, através deste padrão, uma dada taxa velocidade de derretimento glaciar. A análise prova que existe uma elevada actividade glaciar na região, e que a qualidade dos resultados no estudo da deformação dos glaciares tem a influência de vários factores. Para a criação do MDT, foram estimadas as altitudes, e realizada a comparação do MDT interferométrico com o MDT de referência, para efeitos de validação, para a região da Ilha de Livingston, Deception, e Snow. No entanto, para o MDT da Ilha King George, visto não haver um MDT de referência, foi apenas exposto o resultado e realizada uma análise subjectiva.
The study of deformation and the evaluation of glacier melting are important to the assessment of the impact that the glaciers have on climate change. This type of study in remote regions like Antarctica is limited, due to the difficult access. However, Antarctica is one of the most important regions for the study of glacier deformation, as it contains important climate change indicators. Remote sensing techniques, such as interferometry SAR (InSAR rivers), facilitate this type of studies. The work being done in the present thesis consisted on developing a study of ground deformation (ice and glaciers) in areas considered inhospitable by differential interferometry (DInSAR). The study area covers Livingston Island, Deception Island and Snow Island. It was also accomplished a second objective that consists in the creation of digital terrain models (DTM), for the purposes of creation of cartographic products. It will be created two DTMs which will cover the Islands of Livingston, Deception and Snow, and the King George Island, respectively. For the development of the two objectives, it was done automatic processing techniques in satellite images that cover the region. Prior to the completion of processing of SAR interferometry, reference MDT was created, with a resolution of 90 m, trough the combination of a DTM, extracted from contours generated from region maps, and an DTM provided by the National Snow and Ice Data Center (NSIDC). This reference DTM will play an important role later on, in the study of the deformation, for use in the image processing, and for comparison with digital terrain models created. The InSAR process consists, therefore, in carrying out processing techniques in two satellite images, of the same area. The product that comes out of the realization of these techniques will be an interferogram. Once obtained this product, for the study of deformation (DInSAR), an automatic subtraction is performed between the reference DTM and the interferogram, generating a differential interferogram. This differential interferograma represents ground deformation. In the study of deformation, 14 interferograms were processed, between 1993 and 2000 periods. The analysis is divided by three tracks, and within these tracks in various regions. This analysis is performed in subjective way, i.e. by counting the fringe pattern in interferograms, and assuming a melting glacier velocity rate, through this pattern. The analysis proves that there is high glacial activity in the region, and that the quality of results in the study of deformation of glaciers had the influence of several factors. For the creation of MDT, the altitudes were estimated, and a comparison was held between the DTM InSAR created and the reference DTM, for purposes of validation, for the region of Livingston Island, Deception, and Snow. However, for MDT the island King George, since there is no reference DTM, only the result was exposed and subjective analysis was held.
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50

Alibakhshikenari, M., B. S. Virdee, C. H. See, Raed A. Abd-Alhameed, F. Falcone, and E. Limiti. "Surface wave reduction in antenna arrays using metasurface inclusion for MIMO and SAR systems." 2019. http://hdl.handle.net/10454/18126.

Full text
Abstract:
Yes
An effective method is presented for suppressing mutual coupling between adjacent radiating elements which is based on metasurface isolation for MIMO and synthetic aperture radar (SAR) systems. This is achieved by choking surface current waves induced over the patch antenna by inserting a cross-shaped metasurface structure between the radiating elements. Each arm of the cross-shaped structure constituting the metasurface is etched with meander-line slot (MLS). Effectiveness of the metasurface is demonstrated for a2×2antenna array that operates over six frequency sub-bands in X, Ku and K-bands. With the proposed technique, the maximum improvement achieved in attenuating mutual coupling between neighbouring antennas is: 8.5 dB (8-8.4 GHz), 28 dB (9.6-10.8 GHz), 27 dB (11.7-12.6 GHz), 7.5 dB (13.4-14.2 GHz), 13 dB (16.5-16.8 GHz) and 22.5 dB (18.5-20.3 GHz). Furthermore, with the proposed technique (i) minimum center-to-center separation between the radiating elements can be reduced to 0.26λ0, where λ0 is 8.0 GHz; (ii) use of ground-plane or defected ground structures are unnecessary; (iii) use of short-circuited via-holes are avoided; (iv) it eliminates the issue with poor front-to-back ratio; and (v) it can be applied to existing arrays retrospectively.
H2020-MSCA-ITN-2016 SECRET-722424 and the financial support from the UK Engineering and Physical Sciences Research Council (EPSRC) under grant EP/E0/22936/1
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