This thesis is concerned with a theoretical development of Receiver Autonomous Integrity Monitoring (RAIM) algorithms. Integrity characterizes a navigation system ability to provide timely warning to users when the Global Positioning System (GPS) should not be used for navigation. RAIM algorithms detect, identify GPS anomalies and satellite failures and provide the Horizontal Protection Level (HPL). HPL means the smallest detectable horizontal position error with given probabilities of a false alert and missed detection. The developed algorithms use carrier phase measurements, which compared with code measurements can provide precise positioning and an extremely high level of GPS integrity due to setting a very tight fault detection threshold and HPL. First the linear model based on accumulating a few epochs of single difference carrier phase measurements is presented. Then the estimated integer ambiguities available from the positioning solution are used to develop the other single difference linear model. The typical fault detection and identification methods, used for code measurements, are applied to these linear models, leading to various single difference algorithms. The double difference method is also derived. The maximum position separation technique is used to derive the position space based method, implemented through a set of Kalman filters. Finally, computer simulations are performed to compare the developed various algorithms.

<p> Light detection and ranging (LiDAR) data and field observations were used to create a new tectonogeomorphic strip map along the San Andreas Fault from Wrightwood 47 km southeast to Highland. Three hundred and thirty one geomorphic features were identified and the displacements of 23 offset and deflected streams were measured using Quick Terrain Modeler (QTM). Offsets cluster around 10-50 m, and only one offset is smaller than 5 m, and a few larger offsets (100 m-200 m). </p><p> The primary purpose of this project, besides creating the strip map, was to determine how slip is transferred between the northern San Jacinto fault and Mojave-San Bernardino segments in the Cajon Pass area. Previously published slip rate data suggests slip transfer from the San Jacinto fault to the San Andreas fault between Badger Canyon and Cajon Creek at Cajon Pass area. However, there are no significant changes in offset amounts along the northern end of the San Bernardino segment, and the most likely location for slip transfer would be Cajon Pass.</p>

<p> Remotely sensed MODIS fire detections were used to examine wildfire variability from 2003-2011 in southeast Louisiana, and to determine if the Deepwater Horizon oil spill and hurricanes may have impacted fire frequency and intensity. Despite low wildfire detection rates, around 60% for fires at least 1 km² or greater, the MODIS fire product provided a consistent and reliable source of wildfire data. As a result of Hurricane Katrina, wildfire detection frequencies doubled their average numbers during the fall of 2005 in inland areas and during the spring of 2006 in inland and coastal marsh areas. Strangely enough, the oil spill may have contributed to lower fire frequencies in the summer of 2010 and spring of 2011 inland. Neither hurricane Katrina nor the oil spill were found to have an effect on fire intensity, and the spatial distribution of wildfires remained relatively constant over the study area after both disasters. </p>

<p> Shipping, the ocean transportation of people and goods, moves most world trade, and understanding its effects is required to assess human use of the oceans. This work examines the shipping trade by combining global observations of ship location with vessel identification records, and interpreting the results in an ecological context. By incorporating quality checking methods with volunteered geographic information, I provide a spatially resolved high resolution dataset which links individual ships with their movement patterns and vessel attributes. This contributes knowledge on the state and distribution of shipping, and identifies areas where mitigation of impacts are achievable. </p>

<p> Methods for predicting streamflow in areas with limited or nonexistent measures of hydrologic response commonly rely on regionalization techniques, where knowledge pertaining to gaged watersheds is transferred to ungaged watersheds. Hydrologic response indices have frequently been employed in contemporary regionalization research related to predictions in ungaged basins. In this study, regionalization models were developed using multiple linear regression and regression tree analysis to derive relationships between hydrologic response and watershed physical characteristics for 163 watersheds in the Great Lakes basin. These models provide a means for predicting runoff in ungaged basins at a monthly time step without implementation of any process-based rainfall-runoff model. Major findings from this research study include (1) Monthly runoff in ungaged watersheds was predicted with reasonable skill using regression-based relationships between runoff ratio and watershed physical characteristics; (2) Predictions in ungaged watersheds were highly influenced by the temporal characterization of runoff ratio used to condition the regression models; (3) Watershed classification using regression tree and multiple linear regression techniques resulted in comparable model predictive skill.</p>

<p> The transition between the two distinct structural regimes of the Walker Lane and the Basin and Range allows for complex transtensional fault interactions. The Carson Sink is the surface expression of the interaction of shear and extensional strains that cause both crustal extension and block rotation. This study investigates this tectonic shift at the Soda Lake geothermal field by comparing the direction and rate of deformation from both regional GPS and a 34 sq km 3D seismic survey. The GPS stations in the region estimate the strain field by comparing tensor solutions that show changing direction and magnitude of strain across the Carson Sink. Using stations surrounding the Soda Lake 3D seismic survey, the strain tensor produced is comparable in orientation to Basin and Range strain but has larger magnitudes. To quantify deformation within the Soda Lake 3D seismic survey, we calculate fault dip and offset of a deformed paleo-planer lacustrine mudstone. Plotting the mean dip direction of the faults in the seismic reflectivity, matches the mean surrounding GPS extensional direction, suggesting fault displacement is likely to be normal dipslip. Using a minimum age of 0.51 Ma from nearby sedimentation rates, the measured extension across the 5.4 km length of this study has a rate of 0.19 mm/yr. This is quite a high value for Basin and Range extension and it is likely a result of some influence from the Northern Walker Lane. The lack of an obvious piercing point for shear observed within the seismic volume precludes a clear estimate of strike-slip related motion within the Soda Lake 3D seismic survey. Clear extension and a large fault bend, indicates a localized relay ramp model. With focused extension indicated by two late Quaternary extrusive volcanic bodies, a model of a transtensional pull-apart basin is also considered. Given the few mapped intrabasinal faults at the surface, this study gives a unique view into fault offsets inside the Carson Sink.</p>

<p> Northeastern and mid-Atlantic United States are understudied from the perspective of hurricane vulnerability. In an attempt to fill this gap in research, this dissertation attempted to assess the hurricane vulnerability of the northeastern and mid-Atlantic United States through the construction of a Composite Hurricane Vulnerability Index (CHVI) for 184 counties extending from Maine to Virginia. The CHVI was computed by incorporating indicators of human vulnerability and physical exposure. Human vulnerability was derived from demographic, social and economic characteristics whereas physical exposure was based on attributes of the natural and built up environments. The spatial distribution of the CHVI and its component indices were examined and analyzed to meet the research goals, which were a) to develop indices of human vulnerability, physical exposure and composite hurricane vulnerability for all counties; b) to assess vulnerability distribution in terms of population size, metropolitan status (metropolitan versus non metropolitan counties) and location (coastal versus inland counties); c) to identify the specific underlying causes of vulnerability; d) to identify the significant clusters and outliers of high vulnerability; and e) to examine overlaps between high human vulnerability and high physical exposure in the region.</p><p> Results indicated high overall vulnerability for counties that were metropolitan and / or coastal. Vulnerability was high at both ends of the population continuum. Coastal areas had high natural exposure whereas metropolitan areas had high built exposure. In large metropolitan counties, human vulnerability was influenced most strongly by economic vulnerability. In non-metropolitan and small metropolitan counties, vulnerability was an outcome of a combination of demographic, social and economic factors. Vulnerability clusters and intersections pointed towards high vulnerability in the major cities along the northeastern megalopolis, in the Hampton Roads section of Virginia and in parts of Delmarva Peninsula. </p><p> Research findings have important implications for disaster management. Evidence of relationship of population size, metropolitan status and location with vulnerability levels provides a new perspective to vulnerability assessment. Identification of high vulnerability counties can lead to effective resource allocation and emergency management and mitigation plans. Detection of dominant underlying causes of vulnerability can help develop targeted strategies for vulnerability reduction.</p>

Previous reconstructions for anomaly 5 and older anomalies flanking the Southwest Indian Ridge (SWIR) have indicated no statistically significant evidence for motion between the Nubian and Somalian plates. Recently, an analysis of current plate motion across the SWIR indicates significantly different Nubia-Antarctica and Somalia-Antarctica angular velocities. Herein the motion across the SWIR is examined since chron 5 (11 Ma) and chron 6 (20 Ma). I identify 238 Anomaly 5 crossings, 140 Anomaly 6 crossings, and many fracture zone crossings. The new results show that the Nubia-Antarctica and Somali a-Antarctica rotations differ significantly. The results have several implications. (1) Earlier motion differs significantly from that since 3.2 Ma, implying that Nubia-Somalia motion began before 3.2 Ma. (2) Poles of rotation for motion since chron 5 and since chron 6 poles differ significantly from those after 3.2 Ma suggesting a component of right-lateral shearing has occurred along the East African rift since 11 and 20 Ma. (3) Data suggest that the boundary between Nubia and Somalia is narrow where it intersects the SWIR near the Andrew Bain fracture zone complex.

This thesis is concerned with development and implementation of an efficient and numerically reliable positioning algorithm based on the combination of code pseudorange (C/A) and carrier phase (L1) measurements with cycle slip detection. / In GPS a typical technique for kinematic position estimation is relative positioning where two receivers are used, one receiver is stationary and its exact position is known, the other is roving and its position is to be estimated. We describe the physical situation and give the mathematical model based on the difference of the measurements at the stationary and roving receivers. The model we consider combines both code pseudorange and carrier phase measurements. We then present: a recursive least squares approach for position estimation. We take full account of the structure of the problem to make our algorithm efficient, and use orthogonal transformations to ensure numerical reliability of the algorithm. / At each epoch, possible cycle slips must be detected, otherwise it may significant deteriorate the positioning accuracy. A cycle slip detection method based on the higher-order difference technique, one of typical techniques for cycle slip detection, is developed and incorporated into the preprocess of our positioning algorithm. / Finally, real data testing for our positioning algorithm and cycle slip detection algorithm are performed. The results suggest our algorithms are very effective.

In search and rescue (SAR) and emergency planning operations real-time response is critical, particularly when lives are endangered. Until recently, such operations were planned manually by experts in the field using tools such as templates, protractors and calculators. An initiative from the Department of National Defence of Canada has recommended the development of a prototype computerized tool to help the experts in the planning phase of these operations. / This thesis, which was carried out under PRECARN project Passport, addresses two types of algorithms that are at the core of SAR and emergency planning operations: airborne path planning for surveillance and search, and land path planning for mobility analysis and rescue route determination. / The major limitation associated with these algorithms is the high computational cost incurred from the treatment of vast amounts of data representing elevation, transportation networks, vegetation and other soil characteristics. In addition, the programming complexity of these algorithms is not negligible. These issues demand the high performance computing capabilities and relative ease of programming of today's multiprocessor shared-memory computers, as well as algorithms that are scalable and highly efficient. / Parallel algorithms for visibility analysis and path planning using digital terrain data are proposed. The algorithms have been implemented on a Sun symmetric multiprocessor (SMP) SPARC 20 machine and integrated with the Passport airborne path planning and land path planning software. Results of experiments are presented. Some results are compared with a previous implementation on the MasPar MP-1 and MP-2 massively parallel computers.