849 research outputs found

    Suitability Analysis of Subsea Pipeline Route using GIS

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    The objective of this study is to analyze the least cost subsea pipeline route using GIS. A past project has been adopted in this research. The GIS-generated pipeline route is compared with the existing pipeline route designed using contemporary method. The subsea pipelines are used for hydrocarbon transportation from offshore platform to onshore plant. Criteria considered in least cost path are cost, pipeline routing criteria, installation method, safety and maintenance aspects. Factors affecting pipeline routing include bathymetry, submarine geographical features such as seabed conditions and slopes, obstructions such as coral reefs, wildlife preservation areas, as well as availability of existing services such as pipelines and platforms. Spatial Analyst extension in GIS is used to analyze all these factors through three basic steps and produce the best pipeline route through cost-weighted distance function. First step involves developing discrete cost surfaces in raster datasets from routing criteria datasets. Second step involves combining and weighing all discrete surfaces to create an accumulated cost surface. Third step involves developing least cost path between the source and destination along the accumulated cost surface. The result generated has shown similar alignment with the existing route. The GIS-generated route is 0.09km longer than the existing route. Although longer in length, the least cost route crosses less steep areas at length of three times more than the existing route. It crosses prawns' areas at 4% less than existing route as well. Therefore, the least cost path reduces the construction cost and increases the ease of construction as compared to the existing route. Hence, GIS-generated route satisfies the criteria of economical, least obstructions, safe and ease of construction in producing subsea pipeline route. Comparison between GIS method and contemporary pipeline routing method highlighted unique benefits of GIS that proved its feasibility in pipeline routing improvisation

    Development of a fusion adaptive algorithm for marine debris detection within the post-Sandy restoration framework

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    Recognition of marine debris represent a difficult task due to the extreme variability of the marine environment, the possible targets, and the variable skill levels of human operators. The range of potential targets is much wider than similar fields of research such as mine hunting, localization of unexploded ordnance or pipeline detection. In order to address this additional complexity, an adaptive algorithm is being developing that appropriately responds to changes in the environment, and context. The preliminary step is to properly geometrically and radiometrically correct the collected data. Then, the core engine manages the fusion of a set of statistically- and physically-based algorithms, working at different levels (swath, beam, snippet, and pixel) and using both predictive modeling (that is, a high-frequency acoustic backscatter model) and phenomenological (e.g., digital image processing techniques) approaches. The expected outcome is the reduction of inter-algorithmic cross-correlation and, thus, the probability of false alarm. At this early stage, we provide a proof of concept showing outcomes from algorithms that dynamically adapt themselves to the depth and average backscatter level met in the surveyed environment, targeting marine debris (modeled as objects of about 1-m size). The project relies on a modular software library, called Matador (Marine Target Detection and Object Recognition)

    Offshore marine visualization

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    In 85 B.C. a Greek philosopher called Posidonius set sail to answer an age-old question: how deep is the ocean? By lowering a large rock tied to a very long length of rope he determined that the ocean was 2km deep. These line and sinker methods were used until the 1920s when oceanographers developed the first echo sounders that could measure the water's depth by reflecting sound waves off the seafloor. The subsequent increase in sonar depth soundings resulted in oceanologists finally being able to view the alien underwater landscape. Paper printouts and records dominated the industry for decades until the mid 1980s when new digital sonar systems enabled computers to process and render the captured data streams.In the last five years, the offshore industry has been particularly slow to take advantage of the significant advancements made in computer and graphics technologies. Contemporary marine visualization systems still use outdated 2D representations of vessels positioned on digital charts and the potential for using 3D computer graphics for interacting with multidimensional marine data has not been fully investigated.This thesis is concerned with the issues surrounding the visualization of offshore activities and data using interactive 3D computer graphics. It describes the development of a novel 3D marine visualization system and subsequent study of marine visualization techniques through a number of offshore case studies that typify the marine industry. The results of this research demonstrate that presenting the offshore engineer or office based manager with a more intuitive and natural 3D computer generated viewing environment enables complex offshore tasks, activities and procedures to be more readily monitored and understood. The marine visualizations presented in this thesis take advantage of recent advancements in computer graphics technology and our extraordinary ability to interpret 3D data. These visual enhancements have improved offshore staffs' spatial and temporal understanding of marine data resulting in improved planning, decision making and real-time situation awareness of complex offshore data and activities

    Suitability Analysis of Subsea Pipeline Route using GIS

    Get PDF
    The objective of this study is to analyze the least cost subsea pipeline route using GIS. A past project has been adopted in this research. The GIS-generated pipeline route is compared with the existing pipeline route designed using contemporary method. The subsea pipelines are used for hydrocarbon transportation from offshore platform to onshore plant. Criteria considered in least cost path are cost, pipeline routing criteria, installation method, safety and maintenance aspects. Factors affecting pipeline routing include bathymetry, submarine geographical features such as seabed conditions and slopes, obstructions such as coral reefs, wildlife preservation areas, as well as availability of existing services such as pipelines and platforms. Spatial Analyst extension in GIS is used to analyze all these factors through three basic steps and produce the best pipeline route through cost-weighted distance function. First step involves developing discrete cost surfaces in raster datasets from routing criteria datasets. Second step involves combining and weighing all discrete surfaces to create an accumulated cost surface. Third step involves developing least cost path between the source and destination along the accumulated cost surface. The result generated has shown similar alignment with the existing route. The GIS-generated route is 0.09km longer than the existing route. Although longer in length, the least cost route crosses less steep areas at length of three times more than the existing route. It crosses prawns' areas at 4% less than existing route as well. Therefore, the least cost path reduces the construction cost and increases the ease of construction as compared to the existing route. Hence, GIS-generated route satisfies the criteria of economical, least obstructions, safe and ease of construction in producing subsea pipeline route. Comparison between GIS method and contemporary pipeline routing method highlighted unique benefits of GIS that proved its feasibility in pipeline routing improvisation

    Designing Improved Sediment Transport Visualizations

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    Monitoring, or more commonly, modeling of sediment transport in the coastal environment is a critical task with relevance to coastline stability, beach erosion, tracking environmental contaminants, and safety of navigation. Increased intensity and regularity of storms such as Superstorm Sandy heighten the importance of our understanding of sediment transport processes. A weakness of current modeling capabilities is the ability to easily visualize the result in an intuitive manner. Many of the available visualization software packages display only a single variable at once, usually as a two-dimensional, plan-view cross-section. With such limited display capabilities, sophisticated 3D models are undermined in both the interpretation of results and dissemination of information to the public. Here we explore a subset of existing modeling capabilities (specifically, modeling scour around man-made structures) and visualization solutions, examine their shortcomings and present a design for a 4D visualization for sediment transport studies that is based on perceptually-focused data visualization research and recent and ongoing developments in multivariate displays. Vector and scalar fields are co-displayed, yet kept independently identifiable utilizing human perception\u27s separation of color, texture, and motion. Bathymetry, sediment grain-size distribution, and forcing hydrodynamics are a subset of the variables investigated for simultaneous representation. Direct interaction with field data is tested to support rapid validation of sediment transport model results. Our goal is a tight integration of both simulated data and real world observations to support analysis and simulation of the impact of major sediment transport events such as hurricanes. We unite modeled results and field observations within a geodatabase designed as an application schema of the Arc Marine Data Model. Our real-world focus is on the Redbird Artificial Reef Site, roughly 18 nautical miles offshor- Delaware Bay, Delaware, where repeated surveys have identified active scour and bedform migration in 27 m water depth amongst the more than 900 deliberately sunken subway cars and vessels. Coincidently collected high-resolution multibeam bathymetry, backscatter, and side-scan sonar data from surface and autonomous underwater vehicle (AUV) systems along with complementary sub-bottom, grab sample, bottom imagery, and wave and current (via ADCP) datasets provide the basis for analysis. This site is particularly attractive due to overlap with the Delaware Bay Operational Forecast System (DBOFS), a model that provides historical and forecast oceanographic data that can be tested in hindcast against significant changes observed at the site during Superstorm Sandy and in predicting future changes through small-scale modeling around the individual reef objects

    Characterising the ocean frontier : a review of marine geomorphometry

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    Geomorphometry, the science that quantitatively describes terrains, has traditionally focused on the investigation of terrestrial landscapes. However, the dramatic increase in the availability of digital bathymetric data and the increasing ease by which geomorphometry can be investigated using Geographic Information Systems (GIS) has prompted interest in employing geomorphometric techniques to investigate the marine environment. Over the last decade, a suite of geomorphometric techniques have been applied (e.g. terrain attributes, feature extraction, automated classification) to investigate the characterisation of seabed terrain from the coastal zone to the deep sea. Geomorphometric techniques are, however, not as varied, nor as extensively applied, in marine as they are in terrestrial environments. This is at least partly due to difficulties associated with capturing, classifying, and validating terrain characteristics underwater. There is nevertheless much common ground between terrestrial and marine geomorphology applications and it is important that, in developing the science and application of marine geomorphometry, we build on the lessons learned from terrestrial studies. We note, however, that not all terrestrial solutions can be adopted by marine geomorphometric studies since the dynamic, four- dimensional nature of the marine environment causes its own issues, boosting the need for a dedicated scientific effort in marine geomorphometry. This contribution offers the first comprehensive review of marine geomorphometry to date. It addresses all the five main steps of geomorphometry, from data collection to the application of terrain attributes and features. We focus on how these steps are relevant to marine geomorphometry and also highlight differences from terrestrial geomorphometry. We conclude with recommendations and reflections on the future of marine geomorphometry.peer-reviewe

    SIAR: An Autonomous Ground Robot for Sewer Inspection

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    [Abstract] This paper summarizes the latest advances of the EU Project SIAR-ECHORD++, whose main objective is the design of a new robotic platform for inspecting visitable sewers. The SIAR robot aims to determine the sewer serviceability, to identify critical structural defects, to perform sewer monitoring and eventually to take water or gas samples of the environment. To this end, an autonomous IP67 ground robot equipped with RGB-D sensors and with a powerful wireless communication system is being developed. It is able to perform 3D structure reconstruction in real-time that could be used to detect defects in the sewer structures. This paper presents the key aspects in the design of the platform as well as preliminary experimental results in real sewer systems.This work has been developed under the European project Echord++: European Coordination Hub for Robotics Development++ (FP7-601116) inside the challenge \Utility infrastructures and condition monitoring for sewer network. Robots for the inspection and the clearance of the sewer network in cities"https://doi.org/10.17979/spudc.978849749808

    A three-step model to assess shoreline and offshore susceptibility to oil spills: the South Aegean (Crete) as an analogue for confined marine basins

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    This study combines bathymetric, geomorphological, geological data and oil spill predictions to model the impact of oil spills in two accident scenarios from offshore Crete, Eastern Mediterranean. The aim is to present a new three-step method of use by emergency teams and local authorities in the assessment of shoreline and offshore susceptibility to oil spills. The three-step method comprises: (1) real-time analyses of bathymetric, geomorphological, geological and oceanographic data; (2) oil dispersion simulations under known wind and sea current conditions; and (3) the compilation of final hazard maps based on information from (1) and (2) and on shoreline susceptibility data. The results in this paper show that zones of high to very-high susceptibility around the island of Crete are related to: (a) offshore bathymetric features, including the presence of offshore scarps and seamounts; (b) shoreline geology, and (c) the presence near the shore of sedimentary basins filled with unconsolidated deposits of high permeability. Oil spills, under particular weather and oceanographic conditions, may quickly spread and reach the shoreline 5–96 h after the initial accident. As a corollary of this work, we present the South Aegean region around Crete as a valid case-study for confined marine basins, narrow seaways, or interior seas around island groups

    Urban morphology analysis by remote sensing and gis technique, case study: Georgetown, Penang

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    This paper was analysed the potential of applications of satellite remote sensing to urban planning research in urban morphology. Urban morphology is the study of the form of human settlements and the process of their formation and transformation. It is an approach in designing urban form that considers both physical and spatial components of the urban structure. The study conducted in Georgetown, Penang purposely main to identify the evolution of urban morphology and the land use expansion. In addition, Penang is well known for its heritage character, especially in the city of Georgetown with more than 200 years of urban history. Four series of temporal satellite SPOT 5 J on year 2004, 2007, 2009 and 2014 have been used in detecting an expansion of land use development aided by ERDAS IMAGINE 2014. Three types of land uses have been classified namely build-up areas, un-built and water bodies show a good accuracy with achieved above 85%. The result shows the built-up area significantly increased due to the rapid development in urban areas. Simultaneously, this study provides an understanding and strengthening a relation between urban planning and remote sensing applications in creating sustainable and resilience of the city and future societies as well
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