Thesis (Ph. D.)--University of California, Riverside, 2009. / Includes abstract. Includes bibliographical references. Issued in print and online. Available via ProQuest Digital Dissertations.

Thesis (M.S.)--Purdue University, 2004. / Available from National Technical Information Service, Springfield, Va., 2004. Includes bibliographical references (leaves 78-80). Also available online.

Thesis (M.S.) -- University of Tennessee, Knoxville, 2006. / Title from title page screen (viewed on Sept. 18, 2006). Thesis advisor: John C. Sorochan. Vita. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xi, 117 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 115-117).

<p>The ground penetrating radar (GPR) is one of the most popular and successful sensing modalities that have been investigated for buried target detection (BTD). GPR offers excellent detection performance, however, it is limited by a low rate of advance (ROA) due to its short sensing standoff distance. Standoff distance refers to the distance between the sensing platform and the location in front of the platform where the GPR senses the ground. Large standoff (high ROA) sensing modalities have been investigated as alternatives to the GPR but they do not (yet) achieve comparable detection performance. Another strategy to improve the ROA of the GPR is to combine it with a large standoff sensor within the same BTD system, and to leverage the benefits of the respective modalities. This work investigates both of the aforementioned approaches to improve the ROA of GPR systems using statistical modeling techniques. The first part of the work investigates two large-standoff modalities for BTD systems. New detection algorithms are proposed in both cases with the goal of improving their detection performance so that it is more comparable with the GPR. The second part of the work investigates two methods of combining the GPR with a large standoff modality in order to yield a system with greater ROA, but similar target detection performance. All proposed statistical modeling approaches in this work are tested for efficacy using real field-collected data from BTD systems. The experimental results show that each of the proposed methods contribute towards the goal of improving the ROA of BTD systems.</p> / Dissertation

Thesis (MScEng)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: An antenna for ground level deployed Ground Penetrating Radar applications is presented. The antenna is matched to the ground via a low impedance dielectric matching section improving the radiation pattern and input impedance characteristics. A bowtie antenna was used for the design with the edges rounded to stabilize the resonant frequency. The radiation pattern was focused to the one side of the antenna for ground penetration using a non-absorptive metallic cylindrical air filled cavity. Edge reflections from the antenna were reduced by means of discrete resistor terminations between the antenna and the cavity. A wire equivalent of the solid metallic antenna was investigated giving similar characteristics to that of the solid antenna. The radiation pattern deformation arising from transmitting a wave from an antenna in air into the ground due to the impedance mismatch was investigated. This was overcome with the use of a polypropylene dielectric slab inserted between the antenna and the ground. Together with improving the radiation pattern the antenna was less sensitive to ground parameter variations and to an air gap introduced between the slab and the ground. This was implemented as a wheel mounted system with adjustable height settings depending on the terrain. A pair of mounted antennas was constructed to be tested on an existing bistatic Stepped Frequency Continuous Wave radar operating in the 50-400 MHz band developed by the University of Cape Town. This antenna is seen as providing a solution to the problem of coupling an antenna to a low wave impedance medium such as ground. / AFRIKAANSE OPSOMMING: 'n Antenne word vir Grond Penetrerende Radar toepassings voorgestel. Dit is spesifiek ontwikkel vir oppervlak ontplooide stelsels ontwerp. Die antenne is aangepas tot die grond deur middel van 'n diëlektriese aanpassingseksie wat die starlingspatroon en intree-impedansie karakteristieke verbeter. Die antenne is tot die grond toe aangepas deur middel van 'n diëlektriese aanpassingseksie wat die starlingspatroon en intree-impedansie karakteristieke verbeter. 'n Strikdas antenne was gebruik vir die ontwerp, met die kante gerond om die resonante freqwensie te stabiliseer. Om die stralingspatroon van die antenne na een kant toe te fokus was 'n nie-absorbeerede metaleiese, luggevulde, silindriese holte daaragter geplaas om die energie vorentoe te weerkaats. Weerkaatsings van die rand van die antenne word onderdruk met behulp van koppelende weerstande tussen die antenne en die holte. A draad ekwivalent van die antenne was ook ondersoek met goeie ooreenstemming met die soliede strikdas. Die impedansie wanaanpassing wat ontstaan as 'n antenne wat in lug is, in die grond in straal veroorsaak dat die stralingspatroon van die antenne vervorm word. Dit was gevind dat deur 'n aanpassings blad van 'n diëlektriese materiaal, naamlik polipropileen, gebruik te maak tussen die antenne en die grond dat dit die probleem oplos. Saam met dit was gevind dat die antenne minder sensitief was vir veranderings in grondparameters en ook vir 'n lug gaping tussen die blad en die grond. Die het gemaak dat die antenne op wiele gemonteer kon word met verstelbare hoogte afhangend van die terrein. 'n Stel geskaleerde antennes was gemaak om op 'n beskikbare bistatiese Trap Frekwensie Kontinue Golf radar te werk. Dit werk oor die 50-400 MHz band en was ontwikkel deur die Universitiet van Kaapstad. Die antenne word gesien as 'n oplossing vir antenne koppelingsprobleme ondervind by laë golf impedansie materiale.

[pt] O método GPR Ground Penetrating Radar foi empregado nesta pesquisa visando estimar suas potencialidades como uma metodologia viável para os estudos geológicos, geotécnicos e ambientais em condições brasileiras.Para o alcance deste objetivo foram realizados ensaios em campo procurando avaliar a capacidade deste método na detecção das alterações provenientes da ação intempérica na formação do solo residual, ou seja, estimar a profundidade e espessura dos horizontes pedológicos, e o topo rochoso em um perfil geotécnio. Foram também realizados ensaios em laboratório onde fez-se o monitoramento do efeito da contaminação por hidrocarbonetos em blocos indeformados de solo residual, tanto em condições não saturadas, quanto na zona de saturação, procurando avaliar a aplicabilidade do método GPR na detecção deste tipo de contaminante.Os resultados obtidos permitiram imagear com boa resolução os contrastes bruscos, como o topo da rocha sã e blocos inclusos no solo, mas não a detecção nítida dos horizontes no perfil; e pela análise do monitoramento da contaminação, ainda é recente afirmar que o método GPR possa ser empregado com grande eficiência na detecção de contaminantes orgânicos em solo residual. / [en] The GPR method Ground Penetration Radar was used in this work, aiming at estimating its potentialities as a viable methodology to geological, geotechnical and environmental studies of Brazilian soil-rock conditions.In order to reach this objective, in situ tests have been carried out to evaluate the capability of the method in the detection of characteristics of weathering profiles in residual soils. In this case, the aim was to estimate the depth and width of pedological horizons and the bedrock in a geotechnical profile. Laboratory tests were also carried out in blocks of undisturbed residual soil of gnaissic origin. In these blocks, the effects of contamination by petroleum hydrocarbons were monitored. Both the unsaturated and the vadose zones have been monitored. The main objective in relation to the GPR was to evaluate the applicability of the method in the detection of such contaminants.The results obtained allowed to image gross contacts with good resolution such as soil-intact bedrock contacts and blocks inside soils. However, the clear detection of profile horizons were not well imaged. Regarding the contamination monitoring, it is early to affirm that the GPR method might be employed efficiently in the detection of organic contaminants in residual soils.

Across a large part of the UK highways network the carriageway and pavement foundations are drained by Highway Filter Drains (HFDs). A HFD is a linear trench constructed either at the pavement edge or central reserve, fitted with a porous carrier pipe at the base and backfilled with an initially highly porous aggregate material. This arrangement enables the swift removal of surface runoff and subsurface water from the pavement system minimising road user hazards and eliminating risk of structural damage to the pavement sub-base. The highly porous backfill filters throughout its operational life fines washed from the pavement wearing course or adjacent land. HFDs have been found to be prone to collecting near the basal sections (pipe) or surface layers contaminants or detritus that causes the filter media to gradually block. The process has been defined as HFD clogging and it has been found to lead to reduced drainage capacity and potentially severe drop of serviceability. O&M contractual agreements for DBFO projects usually propose in-service and handback requirements for all assets included in the concession portfolio. Different performance thresholds are thus prescribed for pavements, structures, ancillary assets or street lighting. Similar definitions can be retrieved for drainage assets in such agreements, and these include HFDs. Performance metrics are defined though in a generic language and residual life (a key indicator for major assets that usually drives long-term maintenance planning) is prescribed without indicative means to evaluate such a parameter. Most of pavement maintenance is carried out nowadays using proactive management thinking and engineered assessment of benefits and costs of alternative strategies (what-if scenarios). Such a proactive regime is founded upon data driven processes and asset specific ageing / renewal understanding. Within the spectrum of road management, maintenance Life Cycle Costs are usually generated and updated on an annual basis using inventory and condition data linked to a Decision Support Tool (DST). This enables the assessment and optimisation of investment requirements and projection of deterioration and of treatment impacts aligned to continuous monitoring of asset performance. Following this paradigm shift in infrastructure management, a similar structured methodology to optimise HFD maintenance planning is desired and is introduced in this thesis. The work presented enables the identification of proactive maintenance drivers and potential routes in applying a systemised HFD appraisal and monitoring system. An evaluation of Asset Management prerequisites is thus discussed linked to an overview of strategic requirements to establish such a proactive approach. The thesis identifies condition assessment protocols and focuses on developing the means to evaluate deteriorated characteristics of in service drains using destructive and non-destructive techniques. A probabilistic HFD ageing / renewal model is also proposed using Markov chains. This builds upon existing deterioration understanding and links back to current treatment options and impacts. A filter drain decision support toolkit is lastly developed to support maintenance planning and strategy generation.

[pt] O presente trabalho tem por objetivo obter e reunir informações de dentro e do entorno da Lagoa de Jacarepaguá, Rio de Janeiro, e realizar modelagens para auxiliar na gestão governamental da área, muito propendida em função do seu crescimento populacional e sua visibilidade devido aos eventos esportivos que ocorrerão no local, em especial, os Jogos Olímpicos de 2016. Foram realizadas duas modelagens, uma batimétrica e uma geológica, que obedeceram à mesma metodologia de trabalho: coleta de dados, desenvolvimento e validação do modelo através de sondagens geofísicas utilizando o georradar. Para a primeira modelagem foi realizada a batimetria na Lagoa, adquirindo-se profundidades georreferenciadas em campo para elaboração de modelos 3D e 2D das profundidades, identificando assim, cavas provenientes de dragagens para aterros de empreendimentos às suas margens. Por fim, foram realizadas sondagens GPR no interior da Lagoa com o intuito de se comparar com seções pré-determinadas do modelo. No entanto os radargramas não apresentaram bons resultados devido à condutividade elétrica da água, ainda salina apesar da distância do mar. Já a segunda modelagem foi desenvolvida a partir de dados obtidos de sondagens pré-existentes na área que resultaram em modelos 3D, Litológicos e Cronoestratigráficos, donde foram traçadas seções transversais para obter uma visualização espacial melhor. A validação deste modelo, a partir da comparação de seções GPR com seções extraídas do modelo, obteve resultados satisfatórios, ratificando assim o modelo geológico processado. A partir deste modelo geológico foram identificadas camadas em profundidades específicas, localizando assim zonas com concentrações de solos moles na área de estudo. / [en] The present work has the goal of obtaining and gathering pieces of information from the inside and surrounding of Jacarepaguá Lagoon, Rio de Janeiro, and to make models to help in the governmental management of the area, that is so featured because of its population growth and its visibility due to sporting events that will take place in this location, specially the 2016 Olympic Games. Two models have been made, bathymetric and geological ones, which followed the same work methodology: data collection, development and validation of the model through geophysical survey using georadar. For the first model a bathymetry was done in Lagoon getting georeferrenced depths on field to elaborate 3D and 2D models of depths, in order to identify ditches originated from dredging of embankments of actions on its borders. Finally, GPR (Ground Penetration Radar) surveys were made on the inside of Lagoon with the purpose to compare the predetermined sections of the model. Although the radargrams did not show good results due to the water electric conductivity, the water was still saline despite the distance of the ocean. The second model was developed based on data from pre-existing surveys of the area that achieved 3D models, lithological and cronostratigraphic, where transverse sections were done so that it could be possible to obtain a better space visualization. The validation of this model from the comparison of GPR sections with sections extracted from the model, obtained satisfactory results, complementing the geological processed model interpretation. From this geological model, layers were identified in specific depths, locating concentrated zones of soft soils on the studying area.

No registro estratigráfico da Planície Costeira do Rio Grande do Sul estão presentes quatro sequências deposicionais de alta frequência, correspondentes a quatro sistemas do tipo laguna-barreira (I a IV). Estas sequências possuem idades pleistocênicas e holocênica e se desenvolveram em resposta a ciclos glacioeustáticos da ordem de 100 ka. O sistema costeiro holocênico, relacionado à sequência mais jovem (IV), possui setores contemporâneos com padrões de empilhamento opostos. Partindo desta observação duas hipóteses foram formuladas e investigadas. A primeira hipótese refere-se à existência de padrões de empilhamento opostos também nas sequências deposicionais mais antigas (I, II e III) e a segunda é a de que estes padrões estejam expressos na morfologia das barreiras costeiras. Uma análise geomorfológica e estratigráfica foi realizada através das geotecnologias, com o emprego do sensoriamento remoto, do geoprocessamento, de sistemas de posicionamento e do método geofísico do georradar. Os dados foram obtidos em diferentes setores da planície costeira, com enfoque na região sul, entre a fronteira com o Uruguai (Chuí) e a desembocadura da Lagoa dos Patos (Rio Grande). Nesta região, estão presentes os sistemas laguna-barreira II, III e IV, portanto estes contaram com um maior detalhamento. As interpretações realizadas permitiram estabelecer um arcabouço estratigráfico, com a definição das principais superfícies chave e tratos de sistemas, além de um modelo de evolução paleogeográfica para a região sul. A existência dos padrões de empilhamento retrogradacional, progradacional e degradacional foi constatada nas sequências deposicionais mais antigas. Ainda que estas não tenham sido datadas foi possível inferir que comportamentos distintos tenham ocorrido simultaneamente ao longo das linhas de costa relacionadas a estas sequências deposicionais. A variabilidade do comportamento dos sistemas costeiros foi verificada também através das suas características morfológicas, as quais possuem grande influência em seu potencial de preservação. Contudo, alterações posteriores, de origem erosiva e/ou deposicional, modificaram significativamente as feições originais. A aplicação das geotecnologias referidas acima, através da perspectiva da estratigrafia moderna, permitiu ampliar o conhecimento acerca dos sistemas deposicionais costeiros, especialmente das sequências relacionadas aos sistemas laguna-barreira II e III. / The stratigraphic record of Rio Grande do Sul Coastal Plain embraces four high-frequency depositional sequences corresponding to four barrier-lagoon systems (I to IV). These sequences have been developed during the Pleistocene and Holocene, in response to glacioeustatic cycles of 100 ka. The Holocene coastal system, related to the younger sequence (IV), exhibits contemporaneous sectors with opposites stacking patterns. From this observation, two hypotheses were formulated and investigated. The first hypothesis was that the opposite stacking patterns also exist in the older depositional sequences (I, II and III), and the second was that these patterns are expressed, today, in the morphology of the coastal barriers. A geomorphologic and stratigraphic analysis was performed applying various geotechnologies, like remote sensing, geoprocessing, positioning systems and the geophysical method of ground penetrating radar (GPR). The data were obtained in different sectors of the coastal plain, with a focus on the southern region between the border with Uruguay (Chui) and the inlet of Lagoa dos Patos lagoon (Rio Grande). In this region the barrier-lagoon systems II, III and IV were identified and studied in greater detail. The interpretations allowed establishing a stratigraphic framework, setting out the main key surfaces and systems tracts, and a paleogeographic model of the evolution of the southern coastal plain. The existence of retrogradational, progradational and degradacional stacking patterns was found in the older sequences. Although the absolute age of these units has not been determined, it was possible to infer that different behaviors have occurred simultaneously along the shorelines related to these depositional sequences. The variability on the behavior of the coastal systems was also verified by their morphological characteristics, which have great influence on their preservation potential. However, subsequent changes due to erosive and/or depositional events may have significantly modified the original features. The application of geotechnologies from the perspective of modern stratigraphy improved the knowledge of coastal depositional systems, especially of the sequences related to barrier-lagoon systems II and III.