201 research outputs found

    Dual smoothing for marine oil spill segmentation

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    This is the author accepted manuscriptWe present a novel marine oil spill segmentation method that characterizes two smoothing modules at the label level and the pixel level separately. At the label level, we exploit the rolling guidance filter for smoothing the label cost volumes. It enables scale-aware labeling and thus alleviates the ambiguous segmentation that blurs the detailed structures of oil spills. At the pixel level, we adapt a cooperative model for smoothing higher order pixel variations, which has the potential of preserving elongated strips that often arise in oil spills. We integrate the two smoothing modules operating at different levels into an energy minimization formulation, which is referred to as dual smoothing. The coupling of the two smoothing modules enables an effective complement to each other such that the specific structures of oil spills are accurately characterized. We compute the optimal labeling of the dual-smoothing framework based on graph cuts. The proposed dual-smoothing framework is especially effective in segmenting elongated and detailed oil spills, and the experimental results demonstrate its advantages over thresholding- and graph-cut-based segmentations.Royal Societ

    Unsupervised multi-scale change detection from SAR imagery for monitoring natural and anthropogenic disasters

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    Thesis (Ph.D.) University of Alaska Fairbanks, 2017Radar remote sensing can play a critical role in operational monitoring of natural and anthropogenic disasters. Despite its all-weather capabilities, and its high performance in mapping, and monitoring of change, the application of radar remote sensing in operational monitoring activities has been limited. This has largely been due to: (1) the historically high costs associated with obtaining radar data; (2) slow data processing, and delivery procedures; and (3) the limited temporal sampling that was provided by spaceborne radar-based satellites. Recent advances in the capabilities of spaceborne Synthetic Aperture Radar (SAR) sensors have developed an environment that now allows for SAR to make significant contributions to disaster monitoring. New SAR processing strategies that can take full advantage of these new sensor capabilities are currently being developed. Hence, with this PhD dissertation, I aim to: (i) investigate unsupervised change detection techniques that can reliably extract signatures from time series of SAR images, and provide the necessary flexibility for application to a variety of natural, and anthropogenic hazard situations; (ii) investigate effective methods to reduce the effects of speckle and other noise on change detection performance; (iii) automate change detection algorithms using probabilistic Bayesian inferencing; and (iv) ensure that the developed technology is applicable to current, and future SAR sensors to maximize temporal sampling of a hazardous event. This is achieved by developing new algorithms that rely on image amplitude information only, the sole image parameter that is available for every single SAR acquisition. The motivation and implementation of the change detection concept are described in detail in Chapter 3. In the same chapter, I demonstrated the technique's performance using synthetic data as well as a real-data application to map wildfire progression. I applied Radiometric Terrain Correction (RTC) to the data to increase the sampling frequency, while the developed multiscaledriven approach reliably identified changes embedded in largely stationary background scenes. With this technique, I was able to identify the extent of burn scars with high accuracy. I further applied the application of the change detection technology to oil spill mapping. The analysis highlights that the approach described in Chapter 3 can be applied to this drastically different change detection problem with only little modification. While the core of the change detection technique remained unchanged, I made modifications to the pre-processing step to enable change detection from scenes of continuously varying background. I introduced the Lipschitz regularity (LR) transformation as a technique to normalize the typically dynamic ocean surface, facilitating high performance oil spill detection independent of environmental conditions during image acquisition. For instance, I showed that LR processing reduces the sensitivity of change detection performance to variations in surface winds, which is a known limitation in oil spill detection from SAR. Finally, I applied the change detection technique to aufeis flood mapping along the Sagavanirktok River. Due to the complex nature of aufeis flooded areas, I substituted the resolution-preserving speckle filter used in Chapter 3 with curvelet filters. In addition to validating the performance of the change detection results, I also provide evidence of the wealth of information that can be extracted about aufeis flooding events once a time series of change detection information was extracted from SAR imagery. A summary of the developed change detection techniques is conducted and suggested future work is presented in Chapter 6

     Ocean Remote Sensing with Synthetic Aperture Radar

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    The ocean covers approximately 71% of the Earth’s surface, 90% of the biosphere and contains 97% of Earth’s water. The Synthetic Aperture Radar (SAR) can image the ocean surface in all weather conditions and day or night. SAR remote sensing on ocean and coastal monitoring has become a research hotspot in geoscience and remote sensing. This book—Progress in SAR Oceanography—provides an update of the current state of the science on ocean remote sensing with SAR. Overall, the book presents a variety of marine applications, such as, oceanic surface and internal waves, wind, bathymetry, oil spill, coastline and intertidal zone classification, ship and other man-made objects’ detection, as well as remotely sensed data assimilation. The book is aimed at a wide audience, ranging from graduate students, university teachers and working scientists to policy makers and managers. Efforts have been made to highlight general principles as well as the state-of-the-art technologies in the field of SAR Oceanography

    Seasonal and spatial variability of major organic contaminants in solution and suspension of the Pomeranian Bight

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    Studies of hexachlorocyclohexane-isomers (HCHs) and selected triazine herbicides in solution and suspension were carried out in the Pomeranian Bight in 1995. The concentrations of HCHs and triazines were determined by gas-liquid chromatography (GC) or by GC in connection with quadrupole mass spectrometry(GC/MS). Particulate and dissolved material were separated by means of an in-situ filtration/extraction system. The seasonal variability and regional distribution of the various components were investigated in January, April, July and September 1995. Their distribution in the western Pomeranian Bight is described. The concentrations of individual hexachlorocyclohexane-isomers were in the range of 100–1 000 pg l–1 in solution and 20 to 60 pg l–1 in suspension. The levels of the triazines in solution showed pronounced differences between the individual components (atrazine (2–20 ng l–1), simazine (5–30 ng l–1), terbuthylazine (< 5 ng l–1)), but they were one order of magnitude higher compared with the hexachlorocyclohexane-isomers. The concentration of triazines in suspension was low, often below the limit of detection (25 pg l–1)

    Remote Sensing

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    This dual conception of remote sensing brought us to the idea of preparing two different books; in addition to the first book which displays recent advances in remote sensing applications, this book is devoted to new techniques for data processing, sensors and platforms. We do not intend this book to cover all aspects of remote sensing techniques and platforms, since it would be an impossible task for a single volume. Instead, we have collected a number of high-quality, original and representative contributions in those areas

    Study of the speckle noise effects over the eigen decomposition of polarimetric SAR data: a review

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    This paper is focused on considering the effects of speckle noise on the eigen decomposition of the co- herency matrix. Based on a perturbation analysis of the matrix, it is possible to obtain an analytical expression for the mean value of the eigenvalues and the eigenvectors, as well as for the Entropy, the Anisotroopy and the dif- ferent a angles. The analytical expressions are compared against simulated polarimetric SAR data, demonstrating the correctness of the different expressions.Peer ReviewedPostprint (published version

    Utilizing Extended Continental Shelf (ECS) and Ocean Exploration Mapping Data for Standardized Marine Ecological Classification of the U.S. Atlantic Margin

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    Accurate maps of ocean bathymetry and seafloor habitats are needed to support effective marine ecosystem-based management (EBM) approaches. The central premise of this thesis was to synthesize geomorphological elements of large regions of the deep ocean seafloor to establish standards of characterization for ecosystem-based classification. The approach was to apply semi-automated characterization techniques on seafloor bathymetric data that were originally collected for other purposes. The purpose of generating these maps is ultimately to apply to informing ecosystem-based management for large marine regions. While seafloor classification techniques for habitat classification have been applied in shallow water and generally over more local regions, these techniques have never before been applied at continental-margin scales in such deep water. Over the past decade, the United States has made a substantial investment in seafloor mapping efforts covering over 2.5 million square kilometers of the nation’s potential extended continental shelf (ECS) regions, which extend into deep ocean areas beyond 200 nautical miles from the nation’s shoreline. The entire potential ECS region off the U.S. Atlantic margin has been mapped by researchers at the University of New Hampshire’s Center for Coastal and Ocean Mapping/Joint Hydrographic Center (CCOM/JHC). Extensive complimentary mapping datasets collected by the National Oceanic and Atmospheric Administration’s Office of Ocean Exploration and Research (NOAA OER) have been acquired in adjacent U.S. waters off the East Coast covering the continental slope submarine canyons region and a majority of the Blake Plateau. The focus of this thesis is on demonstrating that data gathered with the initial purpose of establishing a potential extended continental shelf claim can further be used to support EBM efforts and sound marine spatial planning. The approaches developed here could be effectively applied to ECS and ocean exploration data sets collected world-wide to leverage substantial additional value from broad-scale ocean mapping efforts. This thesis posited and tested three hypotheses: 1) Broad-scale bathymetric data of the U.S. Atlantic margin collected for ECS and deep sea exploration purposes are useful to consistently classify ecological marine units of the seafloor and generate value-added characterization maps of large regions. 2) Transparent, repeatable, and efficient semi-automated geomorphic analysis methods employing the Coastal and Marine Ecological Classification Standard (CMECS) as an organizational framework produce useful habitat characterization maps of the U.S. Atlantic margin. 3) Vulnerable cold-water coral (CWC) habitats are identifiable and able to be inventoried and characterized using geomorphic analysis and CMECS classification of bathymetric data. These three research hypotheses were tested through classification and characterization studies of three distinct regions of the U.S. Atlantic margin at different scales (an individual seamount feature, the continental slope and abyssal plains, and a continental margin borderland) ranging across a diversity of marine habitats. An automatic segmentation approach to initially identify landform features from the bathymetry of these study areas was completed and then translated into CMECS classification terminology. Geomorphic terrain classification methods were applied to the continental slope and the abyssal plain of the U.S. Atlantic margin ECS region covering a 959,875 km2 area. Landform features derived from the bathymetry were then translated into complete coverage geomorphology maps of the region utilizing CMECS to define geoforms. Abyssal flats made up more than half of the area (53%), with the continental slope flat class making up another 30% of the total area. Flats of any geoform class (including continental shelf flats and guyot flats) made up 83.06% of the study area. Slopes of any geoform classes make up a cumulative total of 13.26% of the study region (8.27% abyssal slopes, 3.73% continental slopes, 1.25% seamount slopes), while ridge features comprise only 1.82% of the total study area (1.03% abyssal ridges, 0.63 continental slope ridge, and 0.16% seamount ridges). Using methods developed to classify the ECS dataset, bathymetric data from twenty multibeam sonar mapping surveys of the Blake Plateau region were used to derive a standardized geomorphic classification capable of quantifying cold-water coral (CWC) mound habitats. Results documented the most extensive CWC mound province thus far discovered and reported in the literature. Nearly continuous CWC mound features span an area up to 472 km long and 88 km wide, with a core area of high density mounds up to 248 km long by 35 km wide. A total of 59,760 individual peak features were delineated, providing the first estimate of the overall number of potential CWC mounds mapped in the Blake Plateau region to date. Five geomorphic landform classes were mapped and quantified: peaks (342 km2), valleys (2,883 km2), ridges (2,952 km2), slopes (15,227 km2), and flats (49,003 km2). The complex geomorphology of eight subregions was described qualitatively with geomorphic “fingerprints” and quantitatively by measurements of mound density and vertical relief. Ground-truth from 23 submersible dive videos revealed coral rubble to be the dominant substrate component within the peak, ridge, and slope landforms explored, thereby validating the interpretation of these bathymetric features as CWC mounds. Results indicated that the Blake Plateau supports a globally exceptional CWC mound province of heretofore unprecedented scale (at least for now) and diverse morphological complexity. This dissertation has successfully characterized the geomorphology of vast regions of the deep ocean floor off the U.S. Atlantic margin for ecosystem-based management purposes. It has applied techniques and established standards of classification that can be applied to other regions throughout the World. This latter point is critical as there are ongoing international efforts today to map the entirety of the World\u27s oceans at meaningful scales and these techniques can synthesize this information in meaningful ways. Furthermore, the need for such syntheses is paramount in order to successful manage (conserve and preserve) the living and non-living resources of the ocean. This thesis shows a way forward for such endeavors, and emphasizes 1) the applicability of data acquired for other purposes to be applied to this purpose, and 2) the need for standards to define and describe marine habitats so that all governments, managers, biologists, geoscientists, and other ocean stakeholders communicate using the same language

    Earth Resources: A continuing bibliography with indexes, issue 11, October 1976

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    This bibliography lists 714 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1976 and September 1976. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis

    Earth Resources: A continuing bibliography with indexes

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    This bibliography lists 623 reports, articles, and other documents introduced into the NASA scientific and technical information system between April 1 and June 30, 1983. Emphasis is placed on the use of remote sensing and geophysical instrumentation in spacecraft and aircraft to survey and inventory natural resources and urban areas. Subject matter is grouped according to agriculture and forestry, environmental changes and cultural resources, geodesy and cartography, geology and mineral resources, hydrology and water management, data processing and distribution systems, instrumentation and sensors, and economic analysis

    Sox10 regulates enteric neural crest cell migration in the developing gut

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    Concurrent Sessions 1: 1.3 - Organs to organisms: Models of Human Diseases: abstract no. 1417th ISDB 2013 cum 72nd Annual Meeting of the Society for Developmental Biology, VII Latin American Society of Developmental Biology Meeting and XI Congreso de la Sociedad Mexicana de Biologia del Desarrollo. The Conference's web site is located at http://www.inb.unam.mx/isdb/Sox10 is a HMG-domain containing transcription factor which plays important roles in neural crest cell survival and differentiation. Mutations of Sox10 have been identified in patients with Waardenburg-Hirschsprung syndrome, who suffer from deafness, pigmentation defects and intestinal aganglionosis. Enteric neural crest cells (ENCCs) with Sox10 mutation undergo premature differentiation and fail to colonize the distal hindgut. It is unclear, however, whether Sox10 plays a role in the migration of ENCCs. To visualize the migration behaviour of mutant ENCCs, we generated a Sox10NGFP mouse model where EGFP is fused to the N-terminal domain of Sox10. Using time-lapse imaging, we found that ENCCs in Sox10NGFP/+ mutants displays lower migration speed and altered trajectories compared to normal controls. This behaviour was cell-autonomous, as shown by organotypic grafting of Sox10NGFP/+ gut segments onto control guts and vice versa. ENCCs encounter different extracellular matrix (ECM) molecules along the developing gut. We performed gut explant culture on various ECM and found that Sox10NGFP/+ ENCCs tend to form aggregates, particularly on fibronectin. Time-lapse imaging of single cells in gut explant culture indicated that the tightly-packed Sox10 mutant cells failed to exhibit contact inhibition of locomotion. We determined the expression of adhesion molecule families by qPCR analysis, and found integrin expression unaffected while L1-cam and selected cadherins were altered, suggesting that Sox10 mutation affects cell adhesion properties of ENCCs. Our findings identify a de novo role of Sox10 in regulating the migration behaviour of ENCCs, which has important implications for the treatment of Hirschsprung disease.postprin
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