Geography Commons^™

Becoming Native, Patricia Monaghan

Reconstruction: Studies in Contemporary Culture

[First paragraph]

With relentless beaks, a squad of crows attacked a winter field. It was a fine fair Irish field, sweeping upwards in the pale sunlight towards a dark bulwark of rhododendrons surrounding a single gnarled oak, beneath which three ruddy cattle grazed. Welcoming this peaceable scene as an excuse to slow my journey, I parked on the verge and walked to the field's iron gate.

Navigating The Starless Night: Strategies For Understanding Autobiogeography, Matthew Wolf-Meyer, Davin Heckman

Reconstruction: Studies in Contemporary Culture

[First paragraph]

Ancient mapmakers relied upon the presence of celestial bodies for their conceptualization of the world, for their external knowledge-making tools, as if a far-off body could help to make sense of our terrestrial life/as if it couldn't. Cosmology, as a practice, relied on the construction of an external body of knowledge that the local meaning-maker could situate him- or herself into, and more broadly, their entire society and culture -- the interior is determined by its relationship to the exterior (or the exteriorized). For the ancient Greeks then, the font of Western culture, this cosmology works at once …

Processes Of Embodiment And Spatialization In The Writings Of Paul Auster, Markus Rheindorf

Reconstruction: Studies in Contemporary Culture

[First paragraph]

Processes of embodiment and the spatialization of interior categories such as thought and memory are defining characteristics of Paul Auster's novels, essays, and poetry, and a brief survey of these aspects can offer a new perspective on Auster's oeuvre as an organic whole. It is the underlying assumption of this paper that the transformation of interior into exterior constitutes a specific instance of the transpositional processes discussed therein. Within the theoretical framework of cultural studies -- as opposed to the more narrowly defined literary studies -- such transformations can be regarded as processes of embodiment, that is to …

Spectral Response And Spatial Pattern Of Fraser Fir Mortality And Regeneration, Great Smoky Mountains, Usa, Thomas R. Allen

Political Science & Geography Faculty Publications

High elevation Fraser fir (Abies fraseri) forests of the Southern Appalachians have undergone widespread mortality since the introduction of the balsam woolly adelgid in the 1950s. Resulting changes in ecosystem pattern and process (e.g., stand dynamic processes) have greatly affected floral and faunal communities. In this project, we integrated field observations, geographic information system topographic models, and 1988–1998 satellite imagery to analyze spatial and temporal conditions of Fraser fir and spruce-fir ecosystems in Great Smoky Mountains National Park. Tasseled cap indices (brightness, greenness, and wetness) and associated spectral changes for Landsat TM digital data were statistically modeled by …

Trichodesmium Spp.: Numerical Studies Of Resource Competition, Carbohydrate Ballasting, And Remote-Sensing Reflectance, Tonya Denise Clayton

OES Theses and Dissertations

In recent years, a new appreciation for the role of diazotrophy in the oceans has emerged. This dissertation reports on three modeling studies designed to investigate ecological processes associated with Trichodesmium spp., the most conspicuous marine diazotroph: (1) characterization of a generalized model Trichodesmium and issues of macronutrient resource competition; (2) carbohydrate ballasting by Trchodesmium and implications for the formation of surface accumulations; and (3) the vertical distribution of Trichodesmium and implications for detection from space.

The first study focuses on issues of nitrogen and phosphorus competition and ecosystem structure. It utilizes a simple ecosystem model that includes dissolved nitrogen …

A Compact Ozone Differential Absorption Lidar (Dial) Transmitter Using A Solid-State Dye Polymer, Alton L. Jones Jr.

Electrical & Computer Engineering Theses & Dissertations

The measurement of atmospheric ozone is important because in the troposphere it is a pollutant that is toxic to living systems, but in the stratosphere ozone protects life by shielding us from the sun's harmful UV-B radiation.

Laser remote sensing from aircraft using differential absorption lidar (DIAL) has become a very important technique for measuring atmospheric ozone at different altitudes and locations. Current aircraft-based DIAL systems use pulsed Nd:YAG pumped liquid dye lasers, which are then frequency doubled into the UV region, to probe both the stratosphere and troposphere for ozone.

This thesis describes a new potential DIAL laser transmitter …

Wavelength Modulation Spectroscopy Of Water Vapor And Line Center Stabilization At 1.462 Μm For Lidar Applications, Colleen Marie Fitzgerald

Electrical & Computer Engineering Theses & Dissertations

Wavelength modulation spectroscopy was employed to investigate water vapor absorption lines in the 1.462 µm wavelength region using an external-cavity diode laser. These measurements were necessary in the development of a lidar (light detection and ranging) instrument for differential absorption measurement of the concentration and movement of water vapor in the Earth's atmosphere. Differential absorption measurements require that the laser frequency remain stable throughout the duration of the measurement. To ensure this stability, the laser output wavelength is monitored and a feedback control loop set up to minimize laser line drift. Three lines were investigated in the 1.462 µm region. …

Fiber-Optic Coupled Lidar Receiver System To Measure Stratospheric Ozone, David Brent Harper

Electrical & Computer Engineering Theses & Dissertations

A fiber-optic coupled lidar receiver system was constructed to determine ozone concentrations in the stratosphere. The system was used to make ground-based measurements of lidar returns from a UV DIAL system. A fiber-optic cable was used to couple the light from the receiver telescope to the light detector. Photon counting was implemented as the light detection technique. This technique allowed detection of 301 and 311 nm lidar returns up to 27.5 and 32.5 km respectively. A software application was developed to control the photon counting system and perform real-time data analysis of measured lidar returns. DIAL measurements of stratospheric ozone …

Historical Relationships Of Atlantic Slope River Drainages, Eugene G. Maurakis, Diana L. Lipscomb

Virginia Journal of Science

An analysis of the historical relationships of 19 river drainages (St. Lawrence to Altamaha) on the Atlantic slope of the Appalachian Mountains was conducted using the shared presence of 124 native species of cyprinid fishes. This analysis resulted in an area cladogram that suggests that the rivers of the southern Atlantic slope were historically connected to the drainage of three southern rivers (Flint, Chattahoochee, and Apalachicola) which drain into the Gulf of Mexico. The mid Atlantic and northern Atlantic slope rivers appear to be historically related in support of earlier hypotheses that the mid Atlantic region provided a refugium for …

Analysis Of Lunar Basalt Flows In Oceanus Procellarum Using Clementine Data, Noel William Jackson

OES Theses and Dissertations

Remote sensing analyses of data set taken by Clementine in 1994 permit new observations about mineral distribution on the lunar surface, basalt flow stratigraphy, and thus the geologic evolution of the Moon. The northern section of Oceanus Procellarum contains numerous impact craters which penetrated the basalt and thus can be used as natural probes to estimate the number and thicknesses of flows.

I constructed a mosaic taken in three frequencies ( 415 nm, 750 nm, 950 nm), and a Ratio Image (750/415 = red, 750/950 = green, 415/750 = blue). On such an image, red indicates the iron-poor mature highland …

Ocean Surface Maps From Blending Disparate Data Through Normal Mode Analysis, William John Schulz Jr.

OES Theses and Dissertations

Rapid environmental assessment is conducted using disparate data sources in the northwestern Gulf of Mexico. An overview of significant physical features in the Gulf highlights the complexities of the large and meso-scale circulations. Spectral analysis of high resolution current meter and drifter data reveals the significant forcing features detectable by readily available observing techniques. These observations are combined with boundary data extracted from the U.S. Navy's Modular Ocean Data Assimilation System (MODAS) through Normal Mode Analysis (NMA). The NMA blending process is described, and surface maps of velocity and convergence are produced. Using statistical and qualitative techniques, the NMA generated …

Inversion And Analysis Of Remotely Sensed Atmospheric Water Vapor Measurements At 940nm, Jack Cutler Larsen

Mechanical & Aerospace Engineering Theses & Dissertations

The understanding and acceptance of remotely sensed atmospheric data depends strongly on the steps taken to characterize experiment error and validate observations through comparisons to other independent measurements. A formal error analysis of the Stratospheric Aerosol and Gas Experiment II (SAGE II) water vapor operational inversion algorithm is performed and compared to previous results. Random measurement errors were characterized by segmented least-squares profile fitting of the slant path absorption which found the error to be uncorrelated in the stratosphere with estimated variances significantly smaller than expected from 18-30 km. Estimates of null space error were developed from radiosonde hygrometers in …

Development Of A Photon Counting System For Ozone Differential Absorption Lidar Signal Detection, Bradley Allen Eccles

Electrical & Computer Engineering Theses & Dissertations

A photon counting system was assembled and integrated into an existing ozone differential absorption lidar signal detection system to improve the range of ozone measurement. Results of data extraction from decaying ozone return signals are presented. Photomultiplier tube detector models EMI 9214Q and EMI 9B17Q are evaluated and characterized. Detector operating performance was based on tube quantum efficiency, gain, dark current, and linearity. The influence of photomultiplier tube characteristics on photon counting performance are discussed along with the recommended optimum photon counting operating conditions. Two photomultiplier gating schemes, focus grid and four dynode gating, are described for use in photon …

Observation Of Shelfwater Overrunning The Southern Slope Sea, Ajoy Kumar

OES Theses and Dissertations

Analyses of two years (1992 and 1993) of high resolution (1.47 km²) sea surface temperature satellite images of the southern Mid-Atlantic Bight (MAB), showed that unusually extensive overhang of shelf water occurs episodically, and coherently over along shelf distances of several hundred kilometers. These episodes are dubbed overrunning of the Slope Sea by shelf water. The overrunning volume has a "face" and a "back" (southern and northern limit). It transports substantial quantities of shelf water southward, and does not retreat onto the shelf, but eventually joins the western edge of the Gulf Stream in the vicinity of Chesapeake …

A Total Systems Analysis Method For The Conceptual Design Of Spacecraft: An Application To Remote Sensing Imager Systems, Knut I. Oxnevad

Engineering Management & Systems Engineering Theses & Dissertations

Increased emphasis is being placed on improving the performance of space projects, within tighter budgets and shorter development times. This has led to a need for more efficient space system design methods. The research described here represents an effort to develop and evaluate such a method.

Systems engineering and concurrent engineering together provide the theoretical foundation for the method. The method, derived from both this theoretical foundation and ideas from experts in the space industry, emphasizes a total systems analysis approach, taking into account given mission requirements, and the mathematical modeling of interactions between system variables and between subsystems. The …

Autonomous Robot Navigation In Unknown Terrains Using Parallel Numerical Artificial Potential Fields, John C. Schneider

Computer Science Theses & Dissertations

We present a new artificial potential field formulation for resolution complete robot navigation that unifies the purely geometric path planning problem with the lower level force control problem. Our formulation is designed for numerical computation over a massively parallel mesh of processors and is responsive to newly discovered terrain features. It does not suffer from many of the problems commonly associated with potential fields and with adequate resolution provides provably correct, collision free convergence to the goal. In addition, our formulation supports many desirable, practical features required for implementation, such as bounded actuator torques, attainable incremental constructability, realizable computation and …

Flow Kinematics And Dynamics Of The Gulf Stream From Composite Imagery, Caitlin Patrice Mullen

OES Theses and Dissertations

A unique set of contemporaneous satellite-tracked drifters and five-day composite satellite images of the North Atlantic is studied in order to infer the near-surface flow kinematics and dynamics of the Gulf Stream. Using fractal and spectral analyses, two kinematic models, and a potential vorticity model, detailed comparisons are made between these data sets.

Fractal and spectral analyses show that the data set is not fractal, there is no geographic variability, and there is not a strong fractal scaling link between the drifter trajectories and composite temperature fronts as had been postulated by several investigators. These results indicate considerably more work …

Integrated Control Of Thermally Distorted Large Space Antennas, Robert H. Tolson

Mechanical & Aerospace Engineering Theses & Dissertations

Studies on controlling the thermal distortion of large space antennae have generally investigated a single orbital position and have optimized actuator locations based on minimizing the RMS surface deviation from the original parabolic shape. One study showed the benefits of directly using far zone electric field characteristics as the performance measure; but, this approach resulted in a nonlinear programming problem. The objective of the current study is to develop an approach to designing a control system that (1) recognizes the time dependence of the distortion and (2) controls variables that are directly related to far field performance in a quadratic …

Wind Streamline Ambiguity Removal Of Microwave Scatterometer Data, Hans W. Zaepfel

Electrical & Computer Engineering Theses & Dissertations

There is a class of satellite microwave scatterometers that return oceanographic information which includes wind vectors with directional ambiguity. The first part of the ambiguity removal process is to reduce the data to a directional ambiguity of 180°. This thesis shows that wind direction change contains the information required for streamline ambiguity removal and that syntactic pattern recognition techniques can be used to locate the areas of wind direction change. Spreading the information along the areas of wind direction change results in the removal of the streamline ambiguity. The algorithm is implemented and the results are presented showing that it …

Usage And Limitations Of Characteristic Vector Analysis Of Remote Sensing Multispectral Data For The Identification And Quantification Of Water Quality Parameters, Theodore A. Talay

Civil & Environmental Engineering Theses & Dissertations

Recent applications of the technique of characteristic vector analysis to remote-sensing water color data has met with varying degrees of success. It is apparent from these experiments that a more thorough understanding of the informational capability of characteristic vector analysis is needed.

The Development Of A Stepped Frequency Microwave Radiometer And Its Application To Remote Sensing Of The Earth, Richard Forrest Harrington

Electrical & Computer Engineering Theses & Dissertations

The design, development, application, and capabilities of a variable frequency microwave radiometer are described. This radiometer has demonstrated the versatility, accuracy, and stability required to provide contributions to the geophysical understanding of ocean and ice processes. The design technique utilized a closed-loop feedback method, whereby noise pulses were added to the received electromagnetic radiation to achieve a null balance in a Dicke switched radiometer. Stability was achieved through the use of a constant temperature enclosure around the low loss microwave front end. The Dicke reference temperature was maintained to an absolute accuracy of 0.1 K using a closed-loop proportional temperature …

Application Of Satellite Data And Lars' Data Processing Techniques To Mapping Vegetation Of The Dismal Swamp, Jeffrey Allan Messmore

Biological Sciences Theses & Dissertations

This study concerned the feasibility of using digital satellite imagery and automatic data processing (ADP) techniques as a means of mapping swamp forest vegetation. Multispectral scanner data acquired by the Earth Resources Technology Satellite (ERTS-1; renamed LANDSAT-1) was analyzed using ADP techniques developed by Purdue University's Laboratory for Applications of Remote Sensing (LARS). The site for this investigation was the Dismal Swamp, a 210,000 acre swamp forest located south of Suffolk, Va. on the Virginia-North Carolina border. Two basic classification strategies were employed in determining the vegetation mapping capability of ERTS-1 data. The initial classification utilized unsupervised techniques which produced …