WorldWideScience

Sample records for project geophysical imaging

  1. Geophysical data fusion for subsurface imaging

    International Nuclear Information System (INIS)

    Hoekstra, P.; Vandergraft, J.; Blohm, M.; Porter, D.

    1993-08-01

    A geophysical data fusion methodology is under development to combine data from complementary geophysical sensors and incorporate geophysical understanding to obtain three dimensional images of the subsurface. The research reported here is the first phase of a three phase project. The project focuses on the characterization of thin clay lenses (aquitards) in a highly stratified sand and clay coastal geology to depths of up to 300 feet. The sensor suite used in this work includes time-domain electromagnetic induction (TDEM) and near surface seismic techniques. During this first phase of the project, enhancements to the acquisition and processing of TDEM data were studied, by use of simulated data, to assess improvements for the detection of thin clay layers. Secondly, studies were made of the use of compressional wave and shear wave seismic reflection data by using state-of-the-art high frequency vibrator technology. Finally, a newly developed processing technique, called ''data fusion,'' was implemented to process the geophysical data, and to incorporate a mathematical model of the subsurface strata. Examples are given of the results when applied to real seismic data collected at Hanford, WA, and for simulated data based on the geology of the Savannah River Site

  2. Solar Wind Monitor--A School Geophysics Project

    Science.gov (United States)

    Robinson, Ian

    2018-01-01

    Described is an established geophysics project to construct a solar wind monitor based on a nT resolution fluxgate magnetometer. Low-cost and appropriate from school to university level it incorporates elements of astrophysics, geophysics, electronics, programming, computer networking and signal processing. The system monitors the earth's field in…

  3. Geophysical subsurface imaging and interface identification.

    Energy Technology Data Exchange (ETDEWEB)

    Pendley, Kevin; Bochev, Pavel Blagoveston; Day, David Minot; Robinson, Allen Conrad; Weiss, Chester Joseph

    2005-09-01

    Electromagnetic induction is a classic geophysical exploration method designed for subsurface characterization--in particular, sensing the presence of geologic heterogeneities and fluids such as groundwater and hydrocarbons. Several approaches to the computational problems associated with predicting and interpreting electromagnetic phenomena in and around the earth are addressed herein. Publications resulting from the project include [31]. To obtain accurate and physically meaningful numerical simulations of natural phenomena, computational algorithms should operate in discrete settings that reflect the structure of governing mathematical models. In section 2, the extension of algebraic multigrid methods for the time domain eddy current equations to the frequency domain problem is discussed. Software was developed and is available in Trilinos ML package. In section 3 we consider finite element approximations of De Rham's complex. We describe how to develop a family of finite element spaces that forms an exact sequence on hexahedral grids. The ensuing family of non-affine finite elements is called a van Welij complex, after the work [37] of van Welij who first proposed a general method for developing tangentially and normally continuous vector fields on hexahedral elements. The use of this complex is illustrated for the eddy current equations and a conservation law problem. Software was developed and is available in the Ptenos finite element package. The more popular methods of geophysical inversion seek solutions to an unconstrained optimization problem by imposing stabilizing constraints in the form of smoothing operators on some enormous set of model parameters (i.e. ''over-parametrize and regularize''). In contrast we investigate an alternative approach whereby sharp jumps in material properties are preserved in the solution by choosing as model parameters a modest set of variables which describe an interface between adjacent regions in

  4. Oman Drilling Project Phase I Borehole Geophysical Survey

    Science.gov (United States)

    Matter, J. M.; Pezard, P. A.; Henry, G.; Brun, L.; Célérier, B.; Lods, G.; Robert, P.; Benchikh, A. M.; Al Shukaili, M.; Al Qassabi, A.

    2017-12-01

    The Oman Drilling Project (OmanDP) drilled six holes at six sites in the Samail ophiolite in the southern Samail and Tayin massifs. 1500-m of igneous and metamorphic rocks were recovered at four sites (GT1, GT2, GT3 and BT1) using wireline diamond core drilling and drill cuttings at two sites (BA1, BA2) using air rotary drilling, respectively. OmanDP is an international collaboration supported by the International Continental Scientific Drilling Program, the Deep Carbon Observatory, NSF, NASA, IODP, JAMSTEC, and the European, Japanese, German and Swiss Science Foundations, and with in-kind support in Oman from Ministry of Regional Municipalities and Water Resources, Public Authority of Mining, Sultan Qaboos University and the German University of Technology. A comprehensive borehole geophysical survey was conducted in all the OmanDP Phase I boreholes shortly after drilling in April 2017. Following geophysical wireline logs, using slim-hole borehole logging equipment provided and run by the Centre National De La Recherche Scientifique (CNRS) and the Université de Montpellier/ Géosciences Montpellier, and logging trucks from the Ministry of Regional Municipalities and Water Resources, were collected in most of the holes: electrical resistivity (dual laterolog resistivity, LLd and LLs), spectral gamma ray (K, U, and Th contents), magnetic susceptibility, total natural gamma ray, full waveform sonic (Vp and Vs), acoustic borehole wall imaging, optical borehole wall imaging, borehole fluid parameters (pressure, temperature, electrical conductivity, dissolved oxygen, pH, redox potential, non-polarized spontaneous electrical potential), and caliper (borehole diameter). In addition, spinner flowmeter (downhole fluid flow rate along borehole axis) and heatpulse flow meter logs (dowhole fluid flow rate along borehole axis) were collected in BA1 to characterize downhole fluid flow rates along borehole axis. Unfortuantely, only incomplete wireline logs are available for

  5. Multiscale geophysical imaging of the critical zone

    Science.gov (United States)

    Parsekian, Andy; Singha, Kamini; Minsley, Burke J.; Holbrook, W. Steven; Slater, Lee

    2015-01-01

    Details of Earth's shallow subsurface—a key component of the critical zone (CZ)—are largely obscured because making direct observations with sufficient density to capture natural characteristic spatial variability in physical properties is difficult. Yet this inaccessible region of the CZ is fundamental to processes that support ecosystems, society, and the environment. Geophysical methods provide a means for remotely examining CZ form and function over length scales that span centimeters to kilometers. Here we present a review highlighting the application of geophysical methods to CZ science research questions. In particular, we consider the application of geophysical methods to map the geometry of structural features such as regolith thickness, lithological boundaries, permafrost extent, snow thickness, or shallow root zones. Combined with knowledge of structure, we discuss how geophysical observations are used to understand CZ processes. Fluxes between snow, surface water, and groundwater affect weathering, groundwater resources, and chemical and nutrient exports to rivers. The exchange of gas between soil and the atmosphere have been studied using geophysical methods in wetland areas. Indirect geophysical methods are a natural and necessary complement to direct observations obtained by drilling or field mapping. Direct measurements should be used to calibrate geophysical estimates, which can then be used to extrapolate interpretations over larger areas or to monitor changing processes over time. Advances in geophysical instrumentation and computational approaches for integrating different types of data have great potential to fill gaps in our understanding of the shallow subsurface portion of the CZ and should be integrated where possible in future CZ research.

  6. Solar wind monitor—a school geophysics project

    Science.gov (United States)

    Robinson, Ian

    2018-05-01

    Described is an established geophysics project to construct a solar wind monitor based on a nT resolution fluxgate magnetometer. Low-cost and appropriate from school to university level it incorporates elements of astrophysics, geophysics, electronics, programming, computer networking and signal processing. The system monitors the earth’s field in real-time uploading data and graphs to a website every few minutes. Modular design encourages construction and testing by teams of students as well as expansion and refinement. The system has been tested running unattended for months at a time. Both the hardware design and software is published as open-source [1, 10].

  7. Fusion of Geophysical Images in the Study of Archaeological Sites

    Science.gov (United States)

    Karamitrou, A. A.; Petrou, M.; Tsokas, G. N.

    2011-12-01

    This paper presents results from different fusion techniques between geophysical images from different modalities in order to combine them into one image with higher information content than the two original images independently. The resultant image will be useful for the detection and mapping of buried archaeological relics. The examined archaeological area is situated in Kampana site (NE Greece) near the ancient theater of Maronia city. Archaeological excavations revealed an ancient theater, an aristocratic house and the temple of the ancient Greek God Dionysus. Numerous ceramic objects found in the broader area indicated the probability of the existence of buried urban structure. In order to accurately locate and map the latter, geophysical measurements performed with the use of the magnetic method (vertical gradient of the magnetic field) and of the electrical method (apparent resistivity). We performed a semi-stochastic pixel based registration method between the geophysical images in order to fine register them by correcting their local spatial offsets produced by the use of hand held devices. After this procedure we applied to the registered images three different fusion approaches. Image fusion is a relatively new technique that not only allows integration of different information sources, but also takes advantage of the spatial and spectral resolution as well as the orientation characteristics of each image. We have used three different fusion techniques, fusion with mean values, with wavelets by enhancing selected frequency bands and curvelets giving emphasis at specific bands and angles (according the expecting orientation of the relics). In all three cases the fused images gave significantly better results than each of the original geophysical images separately. The comparison of the results of the three different approaches showed that the fusion with the use of curvelets, giving emphasis at the features' orientation, seems to give the best fused image

  8. Geophysical images of basement rocks. Geophysical images in the Guianese basement. Airborne geophysical campaign in French Guiana - 1996

    International Nuclear Information System (INIS)

    Delor, C.; Perrin, J.; Truffert, C.; Asfirane, F.; Rossi, Ph.; Bonjoly, D.; Dubreuihl, J.; Chardon, D.

    1998-01-01

    The French Office for Geological and Mining Research (BRGM) has carried out a high sensitivity airborne geophysical survey of northern French Guiana during the second half of 1996. The aim was to realize a high resolution magnetic and gamma spectrometric mapping for future prospecting, land use and environment management. This paper describes in details the geophysical campaign, the material used, the navigation techniques, the processing of magnetic data, the gamma radiation sources used, the spectrometric calibrations and the geologic interpretation of the results. (J.S.)

  9. Geophysics

    CERN Document Server

    Bolt, Bruce

    1973-01-01

    Methods in Computational Physics, Volume 13: Geophysics is a 10-chapter text that focuses with the theoretical solid-earth geophysics. This volume specifically covers the general topics of terrestrial magnetism and electricity, the Earth's gravity field, tidal deformations, dynamics of global spin, spin processing, and convective models for the deep interior. This volume surveys first the construction of mathematical models, such as the representation of the geomagnetic field by assuming arrangements of multipole sources in the core and the fast computer evaluation of two- and three-dimensiona

  10. Image processing of airborne geophysical data: a potential exploration tool for atomic minerals

    International Nuclear Information System (INIS)

    Shanti Kumar, C.; Bhairam, C.L.; Kak, S.N.; Achar, K.K.

    1993-01-01

    Data sets obtained from airborne gamma-ray spectrometric (AGRS) and aeromagnetic (AM) surveys, after necessary correction, are usually presented as profiles or as contour maps for interpretation in mineral exploration and geological analysis. Currently, imaging of the geophysical data sets have been extensively used as they have many advantages in their usage compared to conventional techniques. For the application of image processing techniques to the AGRS and AM data, software programs were customized for converting the digital data compatible to the satellite image processing system (SIPS). The geophysical data has been imaged and rectified to a poly conic projection, using cubic convolution resampling technique. While imaging, the radioelemental concentration values are rescaled to 256 grey levels. Software for the statistical information of radioelements and printing of coloured paper image have also been developed. Some of the image processing techniques used include, generation of colour composite images for preparing radioelemental (eU,eTh, and K) images and radioelemental colour composite images (K,eTh, eU) enabling display of a combined radioelemental distribution. Aeromagnetic data on the other hand are displayed in grey tone, pseudo-colours, and shaded relief images. Many other image enhancement techniques used for improving the display for further interpretation comprise, band ratioing, band combinations, filtering, look up table manipulation, and other similar functions. Advanced image processing techniques such as the principal component analysis (PCA) for understanding the geochemical and geological phenomena and the hue saturation and intensity (HSI) transformation for integration of radioelemental data with its corresponding satellite images facilitated display of radioelemental images draped over the satellite image. Statistics of radioelement and inter-elemental relationship has been obtained. The paper deals with the methodology adopted in the

  11. Geophysical data fusion for subsurface imaging. Final report

    International Nuclear Information System (INIS)

    1995-10-01

    This report contains the results of a three year, three-phase project whose long-range goal has been to create a means for the more detailed and accurate definition of the near-surface (0--300 ft) geology beneath a site that had been subjected to environmental pollution. The two major areas of research and development have been: improved geophysical field data acquisition techniques; and analytical tools for providing the total integration (fusion) of all site data. The long-range goal of this project has been to mathematically, integrate the geophysical data that could be derived from multiple sensors with site geologic information and any other type of available site data, to provide a detailed characterization of thin clay layers and geological discontinuities at hazardous waste sites

  12. Geophysical data fusion for subsurface imaging. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    This report contains the results of a three year, three-phase project whose long-range goal has been to create a means for the more detailed and accurate definition of the near-surface (0--300 ft) geology beneath a site that had been subjected to environmental pollution. The two major areas of research and development have been: improved geophysical field data acquisition techniques; and analytical tools for providing the total integration (fusion) of all site data. The long-range goal of this project has been to mathematically, integrate the geophysical data that could be derived from multiple sensors with site geologic information and any other type of available site data, to provide a detailed characterization of thin clay layers and geological discontinuities at hazardous waste sites.

  13. Geophysical monitoring of active hydrologic processes as part of the Dynamic Underground Stripping Project

    International Nuclear Information System (INIS)

    Newmark, R.L.

    1992-05-01

    Lawrence Livermore National Laboratory, in collaboration with University of California at Berkeley and Lawrence Berkeley Laboratory, is conducting the Dynamic Underground Stripping Project (DUSP), an integrated project demonstrating the use of active thermal techniques to remove subsurface organic contamination. Complementary techniques address a number of environmental restoration problems: (1) steam flood strips organic contaminants from permeable zones, (2) electrical heating drives contaminants from less permeable zones into the more permeable zones from which they can be extracted, and (3) geophysical monitoring tracks and images the progress of the thermal fronts, providing feedback and control of the active processes. The first DUSP phase involved combined steam injection and vapor extraction in a ''clean'' site in the Livermore Valley consisting of unconsolidated alluvial interbeds of clays, sands and gravels. Steam passed rapidly through a high-permeability gravel unit, where in situ temperatures reached 117 degree C. An integrated program of geophysical monitoring was carried out at the Clean Site. We performed electrical resistance tomography (ERT), seismic tomography (crossborehole), induction tomography, passive seismic monitoring, a variety of different temperature measurement techniques and conventional geophysical well logging

  14. Documenting Bronze Age Akrotiri on Thera Using Laser Scanning, Image-Based Modelling and Geophysical Prospection

    Science.gov (United States)

    Trinks, I.; Wallner, M.; Kucera, M.; Verhoeven, G.; Torrejón Valdelomar, J.; Löcker, K.; Nau, E.; Sevara, C.; Aldrian, L.; Neubauer, E.; Klein, M.

    2017-02-01

    The excavated architecture of the exceptional prehistoric site of Akrotiri on the Greek island of Thera/Santorini is endangered by gradual decay, damage due to accidents, and seismic shocks, being located on an active volcano in an earthquake-prone area. Therefore, in 2013 and 2014 a digital documentation project has been conducted with support of the National Geographic Society in order to generate a detailed digital model of Akrotiri's architecture using terrestrial laser scanning and image-based modeling. Additionally, non-invasive geophysical prospection has been tested in order to investigate its potential to explore and map yet buried archaeological remains. This article describes the project and the generated results.

  15. The impact of approximations and arbitrary choices on geophysical images

    Science.gov (United States)

    Valentine, Andrew P.; Trampert, Jeannot

    2016-01-01

    Whenever a geophysical image is to be constructed, a variety of choices must be made. Some, such as those governing data selection and processing, or model parametrization, are somewhat arbitrary: there may be little reason to prefer one choice over another. Others, such as defining the theoretical framework within which the data are to be explained, may be more straightforward: typically, an `exact' theory exists, but various approximations may need to be adopted in order to make the imaging problem computationally tractable. Differences between any two images of the same system can be explained in terms of differences between these choices. Understanding the impact of each particular decision is essential if images are to be interpreted properly-but little progress has been made towards a quantitative treatment of this effect. In this paper, we consider a general linearized inverse problem, applicable to a wide range of imaging situations. We write down an expression for the difference between two images produced using similar inversion strategies, but where different choices have been made. This provides a framework within which inversion algorithms may be analysed, and allows us to consider how image effects may arise. In this paper, we take a general view, and do not specialize our discussion to any specific imaging problem or setup (beyond the restrictions implied by the use of linearized inversion techniques). In particular, we look at the concept of `hybrid inversion', in which highly accurate synthetic data (typically the result of an expensive numerical simulation) is combined with an inverse operator constructed based on theoretical approximations. It is generally supposed that this offers the benefits of using the more complete theory, without the full computational costs. We argue that the inverse operator is as important as the forward calculation in determining the accuracy of results. We illustrate this using a simple example, based on imaging the

  16. GOATS Image Projection Component

    Science.gov (United States)

    Haber, Benjamin M.; Green, Joseph J.

    2011-01-01

    When doing mission analysis and design of an imaging system in orbit around the Earth, answering the fundamental question of imaging performance requires an understanding of the image products that will be produced by the imaging system. GOATS software represents a series of MATLAB functions to provide for geometric image projections. Unique features of the software include function modularity, a standard MATLAB interface, easy-to-understand first-principles-based analysis, and the ability to perform geometric image projections of framing type imaging systems. The software modules are created for maximum analysis utility, and can all be used independently for many varied analysis tasks, or used in conjunction with other orbit analysis tools.

  17. Alligator Rivers Analogue project. Geophysics, petrophysics and structure

    International Nuclear Information System (INIS)

    Emerson, D.W.; Mills, K.J.; Hallett, M.S.; Cao, L.Q.; Miyakawa, K.

    1992-01-01

    The geophysical and geological field work at Koongarra (including borehole core logging) showed that the site itself is a folded, faulted, variably fractured Precambrian psammitic and pelitic schist sequence with a quasi-horizontal weathered zone superimposed on the steeply dipping rock fabric. The site is flanked by a high resistivity younger sandstone unit to the northwest and by a magnetic amphibolite/ferricrete sequence to the far southeast. The data interpretations elicited the essential structural and broad lithological elements. Gravity, magnetic and electrical laboratory and field studies confirmed a broad folded fractured sequence of dipping layered host rocks weathered in their upper parts and trending in a southwest-northeast direction. Qualitatively interpreted anomalies indicated the trend of the main groundwater movement to the south where dolomites are thought to act as a sink. These drainage features have SP, resistivity and radiometric expression. The roles of the Kombolgie Sandstone as a source of water and the Koongarra Fault as a barrier or otherwise were not established owing to the lack of sufficient samples for testing and also on account of the difficulty of geophysical access over the site's rugged escarpment. 40 refs., 13 tabs., 69 figs

  18. The Bolmen tunnel project - evaluation of geophysical site investigation methods

    International Nuclear Information System (INIS)

    Stanfors, R.

    1987-12-01

    The report presents geophysical measurements along and adjacent to the tunnel and an evaluation of the ability of the various methods to permit prediction of rock mass parameters of significance to stability and water bearing ability. The evaluation shows that, using airborne electro-magnetic surveys, it was possible to indicate about 80% of alla the zones of weakness more than 50 m wide in the tunnel. Airborne magnetic surveys located about 90% of all dolerite dykes more than 10 m wide. Ground-level VLF and Slingram methods of electro-magnetic measurement indicated 75% and 85% respectively of all zones of weakness more than 50 m wide. Resistivity methods were successfully used to locate clay filled and water-bearing fracture zones. About 75% of the length of tunnel over which resistivity values below 500 ohm m were measured required shotcrete support and pre-grouting. (orig./DG)

  19. Geophysical surveys at the UMTRA project Shiprock, New Mexico site

    International Nuclear Information System (INIS)

    Wightman, E.; Smith, B.; Newlin, B.

    1996-03-01

    Geophysical surveys were performed at the Uranium Mill Tailings Remedial Action (UMTRA) Shiprock site in New Mexico during February 1996. The surveys were designed to locate areas of ground water contamination, consisting largely of sulfate and nitrate salts and uranium. Electrical geophysical methods were used to locate areas of sulfate and nitrate concentrations since these products, when present in ground water, increase its electrical conductivity. These contaminants also increase the density of water, making the water with the highest concentrations of these salts sink to the bottom of the water column. At the Shiprock site, where alluvium is underlain by the impervious Mancos Shale, the saline water will tend to rest in depressions on the shale surface. Seismic refraction surveys were conducted on the floodplain. The site comprises two areas, the terrace and the floodplain, separated by a steep scarp of some 70 feet (ft) (20 meters [m]). Measurements of electrical conductivity were taken over these two areas, searching for possible pockets of saline ground water resting on top of the bedrock. Conductivity surveys were also run to identify fractures within the bedrock that may act as conduits for ground water movement. Several areas of higher than normal conductivity were found on the terrace, including halos of higher conductivities on three sides of the tailings cell. The conductivity measurements searching for fractures found only a small number of minor fracture-like anomalies. These are not considered important. On the floodplain, both conductivity and seismic refraction measurements were taken. The conductivity measurements clearly show areas of high conductivity interpreted to result from ground water contamination. The seismic refraction measurements identified bedrock depressions that may contain denser, and more saline ground water lenses. Generally, the areas of high conductivity coincide with the bedrock depressions

  20. Status of data, major results, and plans for geophysical activities, Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, H.W. [Geological Survey, Menlo Park, CA (USA); Hardin, E.L. [Science Applications International Corp., Las Vegas, NV (USA); Nelson, P.H. [Geological Survey, Denver, CO (USA)] [eds.

    1990-07-01

    This report describes past and planned geophysical activities associated with the Yucca Mountain Project and is intended to serve as a starting point for integration of geophysical activities. This report relates past results to site characterization plans, as presented in the Yucca Mountain Site Characterization Plan (SCP). This report discusses seismic exploration, potential field methods, geoelectrical methods, teleseismic data collection and velocity structural modeling, and remote sensing. This report discusses surface-based, airborne, borehole, surface-to-borehole, crosshole, and Exploratory Shaft Facility-related activities. The data described in this paper, and the publications discussed, have been selected based on several considerations; location with respect to Yucca Mountain, whether the success or failure of geophysical data is important to future activities, elucidation of features of interest, and judgment as to the likelihood that the method will produce information that is important for site characterization. 65 refs., 19 figs., 12 tabs.

  1. Status of data, major results, and plans for geophysical activities, Yucca Mountain Project

    International Nuclear Information System (INIS)

    Oliver, H.W.; Hardin, E.L.; Nelson, P.H.

    1990-07-01

    This report describes past and planned geophysical activities associated with the Yucca Mountain Project and is intended to serve as a starting point for integration of geophysical activities. This report relates past results to site characterization plans, as presented in the Yucca Mountain Site Characterization Plan (SCP). This report discusses seismic exploration, potential field methods, geoelectrical methods, teleseismic data collection and velocity structural modeling, and remote sensing. This report discusses surface-based, airborne, borehole, surface-to-borehole, crosshole, and Exploratory Shaft Facility-related activities. The data described in this paper, and the publications discussed, have been selected based on several considerations; location with respect to Yucca Mountain, whether the success or failure of geophysical data is important to future activities, elucidation of features of interest, and judgment as to the likelihood that the method will produce information that is important for site characterization. 65 refs., 19 figs., 12 tabs

  2. The ICDP Snake River Geothermal Drilling Project: preliminary overview of borehole geophysics

    Science.gov (United States)

    Schmitt, Douglas R.; Liberty, Lee M.; Kessler, James E.; Kuck, Jochem; Kofman, Randolph; Bishop, Ross; Shervais, John W.; Evans, James P.; Champion, Duane E.

    2012-01-01

    Hotspot: The Snake River Geothermal Drilling Project was undertaken to better understand the geothermal systems in three locations across the Snake River Plain with varying geological and hydrological structure. An extensive series of standard and specialized geophysical logs were obtained in each of the wells. Hydrogen-index neutron and γ-γ density logs employing active sources were deployed through the drill string, and although not fully calibrated for such a situation do provide semi-quantitative information related to the ‘stratigraphy’ of the basalt flows and on the existence of alteration minerals. Electrical resistivity logs highlight the existence of some fracture and mineralized zones. Magnetic susceptibility together with the vector magnetic field measurements display substantial variations that, in combination with laboratory measurements, may provide a tool for tracking magnetic field reversals along the borehole. Full waveform sonic logs highlight the variations in compressional and shear velocity along the borehole. These, together with the high resolution borehole seismic measurements display changes with depth that are not yet understood. The borehole seismic measurements indicate that seismic arrivals are obtained at depth in the formations and that strong seismic reflections are produced at lithological contacts seen in the corresponding core logging. Finally, oriented ultrasonic borehole televiewer images were obtained over most of the wells and these correlate well with the nearly 6 km of core obtained. This good image log to core correlations, particularly with regards to drilling induced breakouts and tensile borehole and core fractures will allow for confident estimates of stress directions and or placing constraints on stress magnitudes. Such correlations will be used to orient in core orientation giving information useful in hydrological assessments, paleomagnetic dating, and structural volcanology.

  3. Projecting Images on a Sphere

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A system for projecting images on an object with a reflective surface. A plurality of image projectors are spaced around the object and synchronized such that each...

  4. Geophysical borehole logging and optical imaging of the pilot hole ONK-PH2

    International Nuclear Information System (INIS)

    Lahti, M.; Heikkinen, E.

    2005-01-01

    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of pilot hole ONK-PH2 in ONKALO tunnel at the Olkiluoto site in December 2004. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all the surveys, integration of the data as well as interpretation of the acoustic and borehole radar data. The report describes the field operation, equipment, processing procedures, interpretation results and shows the obtained geophysical and image data. The data as well as the interpretation results are delivered digitally in WellCAD and Excel format. (orig.)

  5. Geophysical borehole logging and optical imaging of the pilot hole ONK-PH2

    Energy Technology Data Exchange (ETDEWEB)

    Lahti, M. [Suomen Malmi Oy, Espoo (Finland); Heikkinen, E. [JP-Fintact Oy, Vantaa (Finland)

    2005-01-15

    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of pilot hole ONK-PH2 in ONKALO tunnel at the Olkiluoto site in December 2004. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all the surveys, integration of the data as well as interpretation of the acoustic and borehole radar data. The report describes the field operation, equipment, processing procedures, interpretation results and shows the obtained geophysical and image data. The data as well as the interpretation results are delivered digitally in WellCAD and Excel format. (orig.)

  6. FY 2000 Annual Report for EMSP Project No.70108 - Effects of Fluid Distribution on Measured Geophysical Properties for Partially Saturated, Shallow Subsurface Conditions

    International Nuclear Information System (INIS)

    Berge, P.A.; Bonner, B.P.; Roberts, J.J.; Wildenschild, D.; Aracne-Ruddle, C.M.; Berryman, J.G.; Bertete-Aguirre, H.; Boro, C.O.; Carlberg, E.D.

    2000-01-01

    Our goal is to improve geophysical imaging of the vadose zone. We will achieve this goal by providing new methods to improve interpretation of field data. The purpose of this EMSP project is to develop relationships between laboratory measured geophysical properties and porosity, saturation, and fluid distribution, for partially saturated soils. Algorithms for relationships between soil composition, saturation, and geophysical measurements will provide new methods to interpret geophysical field data collected in the vadose zone at sites such as Hanford, WA. This report summarizes work after 10 months of a 3-year project. We have modified a laboratory ultrasonics apparatus developed in a previous EMSP project (No.55411) so that we can make velocity measurements for partially-saturated samples rather than fully-saturated or dry samples. We are testing the measurement apparatus using standard laboratory sand samples such as Ottawa sand samples. Preliminary results indicate that we can measure both compressional and shear velocities in these sand samples. We have received Hanford soil samples (sands from split-spoon cores from an uncontaminated site) and expect to make ultrasonic measurements on them also. We have used the LLNL x-ray facility to perform x-ray computed tomography (XCT) imaging for several partially-saturated Ottawa sand and Lincoln sand samples, and have also used the DOE Advance Photon Source at Argonne National Laboratory to make higher-resolution images of some sand samples. Preliminary results indicate that we can image amount and distribution of fluids in homogeneous sand samples. Continuing work from the previous EMSP project, we are testing a new data analysis method for seismic data that is expected to improve interpretation of seismic data from the vadose zone by showing how partial saturation affects seismic parameters. Our results suggest that the planned approach for this research is appropriate, that microstructure is an important factor

  7. Imaging of Ground Ice with Surface-Based Geophysics

    Science.gov (United States)

    2015-10-01

    terrains. Electrical Resistivity Tomography (ERT), in particular, has been effective for imaging ground ice. ERT measures the ability of materials to...13 2.2.1 Electrical resistivity tomography (ERT...Engineer Research and Development Center ERT Electrical Resistivity Tomography GPS Global Positioning System LiDAR Light Detection and Ranging SIPRE

  8. A geophysical toolbox for imaging and characterization of a landfill

    NARCIS (Netherlands)

    Konstantaki, L.A.; Ghose, R.; Draganov, D.S.; Heimovaara, T.J.

    2015-01-01

    Leachate and gas are a product of biochemical reactions occurring inside the landfill. Treatment technologies (e.g., recirculation of leachate) are developed to reduce the production of leachate. Imaging the location of the wet and gas pockets inside the landfill can help improve the treatment

  9. Geophysical imaging of near-surface structure using electromagnetic and seismic waves

    Science.gov (United States)

    Chen, Yongping

    This thesis includes three different studies of geophysical imaging: (1) inference of plume moments from tomograms with cross-hole radar; (2) simulated annealing inversion for near-surface shear-wave velocity structure with microtremor measurements; and (3) time-lapse GPR imaging of water movement in the vadose zone. Although these studies involve different geophysical approaches, they are linked by a common theme---using geophysical imaging to understand hydrologic phenomena or subsurface structure. My first study in this thesis is concerned with the identification of plume moments from geophysical tomograms. Previously geophysical imaging has been applied to characterize contaminant plume migration in groundwater, and to determine plume mass, extent, velocity, and shape. Although tomograms have been used for quantitative inference of plume moments, the reliability of these inferred moments is poorly understood. In general, tomograms represent blurry and blunted images of subsurface properties, as a consequence of limited data acquisition geometry, measurement error, and the effects of regularization. In this thesis, I investigated the effect of tomographic resolution on the inference of plume moments from tomograms. I presented a new approach to quantify the resolution of inferred moments, drawing on concepts from conventional geophysical image appraisal, and also image reconstruction from orthogonal moments. This new approach is demonstrated by synthetic examples in radar tomography. My results indicated that moments calculated from tomograms are subject to substantial error and bias. For example, for many practical survey geometries, crosshole radar tomography (1) is incapable of resolving the lateral center of mass, and (2) severely underpredicts total mass. The degree of bias and error varies spatially over the tomogram, in a complicated manner, as a result of spatially variable resolution. These findings have important implications for the quantitative use

  10. Geophysical tomography for imaging water movement in welded tuff

    International Nuclear Information System (INIS)

    Daily, W.; Ramirez, A.

    1986-01-01

    Alterant tomography has been evaluated for its ability to delineate in-situ water flow paths in a fractured welded-tuff rock mass. The evaluation involved a field experiment in which tomographs of electromagnetic attenuation factor (or attenuation rate) at 300 MHZ were made before, during, and after the introduction to the rock of two different water-based tracers: a plain water and dye solution, and salt water and dye. Alterant tomographs were constructed by subtracting, cell by cell, the attenuation factors derived from measurements before each tracer was added to the rock mass from the attenuation factors derived after each tracer was added. The alterant tomographs were compared with other evidence of water movement in the rock: borescope logs of fractures, and postexperiment cores used to locate the dye tracer on the fractured surfaces. These comparisons indicate that alterant tomography is suitable for mapping water flow through fractures and that it may be useful in inferring which of the fractures are hydrologically connected in the image plane. The technique appears to be sensitive enough to delineate flow through a single fracture and to define fractures with a spatial resolution of about 10 cm on an imaging scale of a few meters. 9 refs., 3 figs

  11. Geophysical image of the hydrothermal system of Merapi volcano

    Science.gov (United States)

    Byrdina, S.; Friedel, S.; Vandemeulebrouck, J.; Budi-Santoso, A.; Suhari; Suryanto, W.; Rizal, M. H.; Winata, E.; Kusdaryanto

    2017-01-01

    We present an image of the hydrothermal system of Merapi volcano based on results from electrical resistivity tomography (ERT), self-potential, and CO2 flux mappings. The ERT models identify two distinct low-resistivity bodies interpreted as two parts of a probably interconnected hydrothermal system: at the base of the south flank and in the summit area. In the summit area, a sharp resistivity contrast at ancient crater rim Pasar-Bubar separates a conductive hydrothermal system (20-50 Ω m) from the resistive andesite lava flows and pyroclastic deposits (2000-50,000 Ω m). The existence of preferential fluid circulation along this ancient crater rim is also evidenced by self-potential data. The significative diffuse CO2 degassing (with a median value of 400 g m-2 d-1) is observed in a narrow vicinity of the active crater rim and close to the ancient rim of Pasar-Bubar. The total CO2 degassing across the accessible summital area with a surface of 1.4 ṡ 105 m2 is around 20 t d-1. Before the 2010 eruption, Toutain et al. (2009) estimated a higher value of the total diffuse degassing from the summit area (about 200-230 t d-1). This drop in the diffuse degassing from the summit area can be related to the decrease in the magmatic activity, to the change of the summit morphology, to the approximations used by Toutain et al. (2009), or, more likely, to a combination of these factors. On the south flank of Merapi, the resistivity model shows spectacular stratification. While surficial recent andesite lava flows are characterized by resistivity exceeding 100,000 Ω m, resistivity as low as 10 Ω m has been encountered at a depth of 200 m at the base of the south flank and was interpreted as a presence of the hydrothermal system. No evidence of the hydrothermal system is found on the basis of the north flank at the same depth. This asymmetry might be caused by the asymmetry of the heat supply source of Merapi whose activity is moving south or/and to the asymmetry in

  12. Asymmetrical hydrothermal system below Merapi volcano imaged by geophysical data.

    Science.gov (United States)

    Byrdina, Svetlana; Friedel, Sven; Budi-Santoso, Agus; Suryanto, Wiwit; Suhari, Aldjarishy; Vandemeulebrouck, Jean; Rizal, Mohhamed H.; Grandis, Hendra

    2017-04-01

    A high-resolution image of the hydrothermal system of Merapi volcano is obtained using electrical resistivity tomography (ERT), self-potential, and CO2 flux mappings. The ERT inversions identify two distinct low-resistivity bodies, at the base of the south flank and in the summit area, that represent likely two parts of an interconnected hydrothermal system. In the summit area, the extension of the hydrothermal system is clearly limited by the main geological structures which are actual and ancient craters. A sharp resistivity contrast at ancient crater rim Pasar-Bubar separates a conductive hydrothermal system (20 - 50 Ωm) from the resistive andesite lava flows and pyroclastic deposits (2000 - 50 000 Ωm). High diffuse CO2 degassing (with a median value of 400g m -2 d -1) is observed in a narrow vicinity of the active crater rim and close to the Pasar-Bubar. The existence of preferential fluid circulation along this ancient crater rim is also evidenced by self-potential data. The total CO2 degassing across the accessible summit area with a surface of 1.4 · 10 5 m 2 is around 20 td -1. Before the 2010 eruption, Toutain et al. (2009) estimated a higher value of the total diffuse degassing from the summit area (about 200 - 230 td -1). This drop in the diffuse degassing can be related to the decrease in the magmatic activity, to the change of the summit morphology or to a combination of these factors. On the south flank of Merapi, the resistivity model shows spectacular stratification. While surficial recent andesite lava flows are characterized by resistivity exceeding 100 000 Ωm, resistivity as low as 10 Ωm has been encountered at a depth of 200 m at the base of the south flank and was interpreted as a presence of the hydrothermal system. We suggest that a sandwich-like structure of stratified pyroclastic deposits on the flanks of Merapi screen and separate the flow of hydrothermal fluids with the degassing occurring mostly through the fractured crater rims

  13. GeomarCD project; an educational CD-Rom about marine geophysics

    Science.gov (United States)

    Diaz, J.; Rubio, E.; Gómez, M.; Gallart, J.

    2009-04-01

    This project aims to introduce the main aspects of marine geophysics experiments to the high school students. We have chosen to present the information in the form an interactive game in which, taking care of the scientific objectives and the technological and logistic resources, the player must found the best strategy to make one of the 3 research projects proposed. Along the game, the player is introduced to the main aspects of the plate tectonics theory and the crustal structure as well as to the main methodologies available (seismics, potencial fields, cores). Rather than being based in theoretical aspects, largely covered by other outreach projects, this work focuses in how a realistic problem can be solved through a field experiment. The game takes place in the researcher's desk and in an oceanographic vessel as the BIO Hesperides and includes the choice of the research project, the design and development of the field work and the interpretation of the results. At the end, the player must complete a questionnaire to elaborate the final report. The correct choice of the appropriate methodologies and its interpretation is necessary to succeed. CD copies in Spanish are freely available upon request.

  14. Final Report DOE Contract No. DE-FG36-04G014294 ICEKAP 2004: A Collaborative Joint Geophysical Imaging Project at Krafla and IDDP P.E. Malin, S.A. Onacha, E. Shalev Division of Earth and Ocean Sciences Nicholas School of the Environment Duke University Durham, NC 27708

    Energy Technology Data Exchange (ETDEWEB)

    Malin, Peter E.; Shalev, Eylon; Onacha, Stepthen A.

    2006-12-15

    In this final report, we discuss both theoretical and applied research resulting from our DOE project, ICEKAP 2004: A Collaborative Joint Geophysical Imaging Project at Krafla and IDDP. The abstract below begins with a general discussion of the problem we addressed: the location and characterization of “blind” geothermal resources using microearthquake and magnetotelluric measurements. The abstract then describes the scientific results and their application to the Krafla geothermal area in Iceland. The text following this abstract presents the full discussion of this work, in the form of the PhD thesis of Stephen A. Onacha. The work presented here was awarded the “Best Geophysics Paper” at the 2005 Geothermal Resources Council meeting, Reno. This study presents the modeling of buried fault zones using microearthquake and electrical resistivity data based on the assumptions that fluid-filled fractures cause electrical and seismic anisotropy and polarization. In this study, joint imaging of electrical and seismic data is used to characterize the fracture porosity of the fracture zones. P-wave velocity models are generated from resistivity data and used in locating microearthquakes. Fracture porosity controls fluid circulation in the hydrothermal systems and the intersections of fracture zones close to the heat source form important upwelling zones for hydrothermal fluids. High fracture porosity sites occur along fault terminations, fault-intersection areas and fault traces. Hydrothermal fault zone imaging using resistivity and microearthquake data combines high-resolution multi-station seismic and electromagnetic data to locate rock fractures and the likely presence fluids in high temperature hydrothermal systems. The depths and locations of structural features and fracture porosity common in both the MT and MEQ data is incorporated into a joint imaging scheme to constrain resistivity, seismic velocities, and locations of fracture systems. The imaging of the

  15. New Insights Into Valley Formation and Preservation: Geophysical Imaging of the Offshore Trinity River Paleovalley

    Science.gov (United States)

    Speed, C. M.; Swartz, J. M.; Gulick, S. P. S.; Goff, J.

    2017-12-01

    The Trinity River paleovalley is an offshore stratigraphic structure located on the inner continental shelf of the Gulf of Mexico offshore Galveston, Texas. Its formation is linked to the paleo-Trinity system as it existed across the continental shelf during the last glacial period. Newly acquired high-resolution geophysical data have imaged more complexity to the valley morphology and shelf stratigraphy than was previously captured. Significantly, the paleo-Trinity River valley appears to change in the degree of confinement and relief relative to the surrounding strata. Proximal to the modern shoreline, the interpreted time-transgressive erosive surface formed by the paleo-river system is broad and rugose with no single valley, but just 5 km farther offshore the system appears to become confined to a 10 km wide valley structure before again becoming unconfined once again 30 km offshore. Fluvial stratigraphy in this region has a similar degree of complexity in morphology and preservation. A dense geophysical survey of several hundred km is planned for Fall 2017, which will provide unprecedented imaging of the paleovalley morphology and associated stratigraphy. Our analysis leverages robust chirp processing techniques that allow for imaging of strata on the decimeter scale. We will integrate our geophysical results with a wide array of both newly collected and previously published sediment cores. This approach will allow us to address several key questions regarding incised valley formation and preservation on glacial-interglacial timescales including: to what extent do paleo-rivers remain confined within a single broad valley structure, what is the fluvial systems response to transgression, and what stratigraphy is created and preserved at the transition from fluvial to estuarine environments? Our work illustrates that traditional models of incised valley formation and subsequent infilling potentially fail to capture the full breadth of dynamics of past river

  16. THE BC CRIBS & TRENCHES GEOPHYSICAL CHARACTERIZATION PROJECT ONE STEP FORWARD IN HANFORDS CLEANUP PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    BENECKE, MN.W.

    2006-02-22

    A geophysical characterization project was conducted at the BC Cribs and Trenches Area, located south of 200 East at the Hanford Site. The area consists of 26 waste disposal trenches and cribs, which received approximately 30 million gallons of liquid waste from the uranium recovery process and the ferrocyanide processes associated with wastes generated by reprocessing nuclear fuel. Waste discharges to BC Cribs contributed perhaps the largest liquid fraction of contaminants to the ground in the 200 Areas. The site also includes possibly the largest inventory of Tc-99 ever disposed to the soil at Hanford with an estimated quantity of 400 Ci. Other waste constituents included high volumes of nitrate and U-238. The geophysical characterization at the 50 acre site primarily included high resolution resistivity (HRR). The resistivity technique is a non-invasive method by which electrical resistivity data are collected along linear transects, and data are presented as continuous profiles of subsurface electrical properties. The transects ranged in size from about 400-700 meters and provided information down to depths of 60 meters. The site was characterized by a network of 51 HRR lines with a total of approximately 19.7 line kilometers of data collected parallel and perpendicular to the trenches and cribs. The data were compiled to form a three-dimensional representation of low resistivity values. Low resistivity, or high conductivity, is indicative of high ionic strength soil and porewater resulting from the migration of nitrate and other inorganic constituents through the vadose zone. High spatial density soil data from a single borehole, that included coincident nitrate concentrations, electrical conductivity, and Tc-99, were used to transform the electrical resistivity data into a nitrate plume. The plume was shown to extend laterally beyond the original boundaries of the waste site and, in one area, to depths that exceeded the characterization strategy. It is

  17. THE BC CRIBS and TRENCHES GEOPHYSICAL CHARACTERIZATION PROJECT: ONE STEP FORWARD IN HANFORD'S CLEANUP PROCESS

    International Nuclear Information System (INIS)

    BENECKE, M.W.

    2005-01-01

    A geophysical characterization project was conducted at the BC Cribs and Trenches Area, located south of 200 East at the Hanford Site. The area consists of 26 waste disposal trenches and cribs, which received approximately 30 million gallons of liquid waste from the uranium recovery process and the ferrocyanide processes associated with wastes generated by reprocessing nuclear fuel. Waste discharges to BC Cribs contributed perhaps the largest liquid fraction of contaminants to the ground in the 200 Areas. The site also includes possibly the largest inventory of Tc-99 ever disposed to the soil at Hanford with an estimated quantity of 400 Ci. Other waste constituents included high volumes of nitrate and U-238. The geophysical characterization at the 50-acre site primarily included high resolution resistivity (HRR). The resistivity technique is a non-invasive method by which electrical resistivity data are collected along linear transects, and data are presented as continuous profiles of subsurface electrical properties. The transects ranged in size from about 400-700 meters and provided information down to depths of 60 meters. The site was characterized by a network of 51 HRR lines with a total of approximately 19.7 line kilometers of data collected parallel and perpendicular to the trenches and cribs. The data were compiled to form a three-dimensional representation of low resistivity values. Low resistivity, or high conductivity, is indicative of high ionic strength soil and porewater resulting from the migration of nitrate and other inorganic constituents through the vadose zone. High spatial density soil data from a single borehole, that included coincident nitrate concentrations, electrical conductivity. and Tc-99, were used to transform the electrical resistivity data into a nitrate plume. The plume was shown to extend laterally beyond the original boundaries of the waste site and, in one area, to depths that exceeded the characterization strategy

  18. Initial comments on the aero geophysical information present at the B and C areas of the Itatira (Brazil) project

    International Nuclear Information System (INIS)

    Castro, Neivaldo Araujo de; Castelo Branco, Raimundo Mariano Gomes

    1999-01-01

    The aero geophysical project called Itatira,, accomplished by LASA Engenharia e Prospeccoes S.A., Between September and November/1977 through contract with NUCLEBRAS, corresponds to one of the first project of this gender accomplished in national territory. In this project were flight more than 80 000 km of linear lines, which covered approximately 38 000 km 2 on the precambrian terrains of the Ceara State, NE Brazil. For several reasons, the total area of the project was subdivided in three sub-areas (A, B and C), each one covered by a different airship (LAS, 1977). This paper presents the geophysical information and preliminary interpretations of the areas B and C that were obtained through the integrated use of the soft wares AUTOCAD r. 14, OASIS MONTAJ r.4.2 and ERMAPPER r.5.5. (author)

  19. A geophysical potential field study to image the Makran subduction zone in SE of Iran

    Science.gov (United States)

    Abedi, Maysam; Bahroudi, Abbas

    2016-10-01

    The Makran subduction wedge as one of the largest subduction complexes has been forming due to the Arabian oceanic lithosphere subducting beneath the Lut and the Afghan rigid block microplates. To better visualize the subducting oceanic crust in this region, a geophysical model of magnetic susceptibility from an airborne magnetic survey (line spacing about 7.5 km) over the Makran zone located at southeast of Iran is created to image various structural units in Iran plate. The constructed geophysical model from the 3D inverse modeling of the airborne magnetic data indicates a thin subducting slab to the north of the Makran structural zone. It is demonstrated that the thickness of sedimentary units varies approximately at an interval of 7.5-11 km from north to south of this zone in the Iranian plate, meanwhile the curie depth is also estimated approximately basement, while such intensity reduces over the Makran. The directional derivatives of the magnetic field data have subtle changes in the Makran, but strongly increase in the Jazmurian by enhancing and separating different structural boundaries in this region. In addition, the density variations of the subsurface geological layers were determined by 3D inversion of the ground-based gravity data over the whole study area, where the constructed density model was in good agreement with the magnetic one. According to the outputs of the magnetic susceptibility and the density contrast, the Arabian plate subducts to the north under the Eurasia with a very low dip angle in the Makran structural zone.

  20. Crump Geyser Exploration and Drilling Project. High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Fairbank, Brian D. [Nevada Geothermal Power Company, Vancouver (Canada); Smith, Nicole [Nevada Geothermal Power Company, Vancouver (Canada)

    2015-06-10

    The Crump Geyser Exploration and Drilling Project – High Precision Geophysics and Detailed Structural Exploration and Slim Well Drilling ran from January 29, 2010 to September 30, 2013. During Phase 1 of the project, collection of all geophysical surveys was completed as outlined in the Statement of Project Objectives. In addition, a 5000-foot full sized exploration well was drilled by Ormat, and preexisting drilling data was discovered for multiple temperature gradient wells within the project area. Three dimensional modeling and interpretation of results from the geophysical surveys and drilling data gave confidence to move to the project into Phase 2 drilling. Geological and geophysical survey interpretations combined with existing downhole temperature data provided an ideal target for the first slim-hole drilled as the first task in Phase 2. Slim-hole 35-34 was drilled in September 2011 and tested temperature, lithology, and permeability along the primary range-bounding fault zone near its intersection with buried northwest-trending faults that have been identified using geophysical methods. Following analysis of the results of the first slim-hole 35-34, the second slim hole was not drilled and subsequent project tasks, including flowing differential self-potential (FDSP) surveys that were designed to detail the affect of production and injection on water flow in the shallow aquifer, were not completed. NGP sold the Crump project to Ormat in August 2014, afterwards, there was insufficient time and interest from Ormat available to complete the project objectives. NGP was unable to continue managing the award for a project they did not own due to liability issues and Novation of the award was not a viable option due to federal award timelines. NGP submitted a request to mutually terminate the award on February 18, 2015. The results of all of the technical surveys and drilling are included in this report. Fault interpretations from surface geology, aeromag

  1. 3D object-oriented image analysis in 3D geophysical modelling

    DEFF Research Database (Denmark)

    Fadel, I.; van der Meijde, M.; Kerle, N.

    2015-01-01

    Non-uniqueness of satellite gravity interpretation has traditionally been reduced by using a priori information from seismic tomography models. This reduction in the non-uniqueness has been based on velocity-density conversion formulas or user interpretation of the 3D subsurface structures (objects......) based on the seismic tomography models and then forward modelling these objects. However, this form of object-based approach has been done without a standardized methodology on how to extract the subsurface structures from the 3D models. In this research, a 3D object-oriented image analysis (3D OOA......) approach was implemented to extract the 3D subsurface structures from geophysical data. The approach was applied on a 3D shear wave seismic tomography model of the central part of the East African Rift System. Subsequently, the extracted 3D objects from the tomography model were reconstructed in the 3D...

  2. A geophysical cross-section of the Hockai Fault Zone (Eastern Belgium): imaging an intraplate weak crustal zone.

    Science.gov (United States)

    Lecocq, T.; Camelbeeck, T.

    2016-12-01

    The Hockai Fault Zone (HFZ) is a NNW-SSE trending structure visible in the regional geomorphology in the Ardennes, Eastern-Belgium. It is situated, between the Pays de Herve (Graben de la Minerie) to the North and the Amblève river, to the South. It crosses the Stavelot Massif, almost perpendicular to the Crête de la Vecquée (Vecquée crest), i.e. the highest crest of the Venn. Faults have been identified or suspected on a contour map of the base of the Tertiary cover (Eocene or Oligocene) in the north western and central Rhenish Massif. These faults are necessary to account for the altitude difference of the base of the cover. The deflection or capture of local rivers show a remarkable alignments on more than 42 km N-S. The alignments are mostly trending SSE-NNW, between N140 and N170, with some potential segments with slightly different orientations. This general orientation has been also evidenced from the analyses of Landsat-1 imagery products. At its crossing with the Vecquée Crest, Demoulin locates the HFZ where the Hoëgne river turns sharply towards the north and crosscuts the quarzitic crest. Demoulin identifies three subparallel faults or fault zones on the Hautes-Fagnes plateau, from East to West: the Eupen faulting zone, the Baelen faulting zone and Hockai faulted zone. In this communication, we report on a large-scale geophysical survey that was conducted in order to search of the Hockai fault zone expression at the surface. The locations to search for the Hockai Fault Zone are based on the surface projection of the 1989/1990 seismic swarm that occurred under the Stavelot Massif, geomorphological evidences and past geophysical surveys in the region. Our objective is not to prove a Quaternary movement of faults, but rather to find reliable evidences of their presence and to analyse their lateral extension. In total, 31 ERT profiles were executed almost parallel to the Vecquée Crest, i.e. a total of 10679 meters of profiles. Four zones are imaged

  3. Multidisciplinary projects and investigations on the solid earth geophysics; Metodi e prospettive per una maggiore conoscenza della crosta terrestre

    Energy Technology Data Exchange (ETDEWEB)

    Slejko, D. [Consiglio Nazionale delle Ricerche, Gruppo Nazionale di Geofisica della Terra Solida, Trieste (Italy)

    2001-07-01

    Physical phenomena that occur in the solid part of the Earth are investigated by Solid Earth Geophysics together with problems related to the shape, location, and characteristics of the different parts that constitute the Earth. Repeated measurements lead the scientists to model the past evolution of the various processes as well as to forecast the future ones. Various disciplines refer to Solid Earth Geophysics, they are: Seismology, Gravimetry, Magnetometry, Geothermics, Geodesy, Geo electromagnetism, and Seismic Exploration. A special citation is due to Applied Geophysics, which are devoted to the identification of minerals, energetic and natural resources. The National Group of Solid Earth Geophysics was constituted in 1978 by CNR for promoting, developing, and coordinating researches related to Solid Earth Geophysics. The limited annual financial budget has conditioned the realisation of relevant multi-disciplinary projects. Nevertheless, important results were obtained in all different fields of Geophysics and were disseminated during the annual conference of the Group. A summary review of the main topics treated during the last conference is given here and some ideas for future research projects are presented. [Italian] La Geofisica della Terra Solida e' quella branca delle scienze e delle tecnologie che prende in considerazione dei fenomeni connessi con le caratteristiche fisiche della parte solida della Terra. La complessita' della costituzione della Terra e della sua evoluzione nel tempo implica che vengano prese in considerazione tutte le fenomenologie che si riescono a misurare e che costituiscono branche diverse della Geofisica: la Sismologia, la Gravimetria, la Magnetometria, la Geotermia, la Geodesia, il Geoelettromagnetismo, la Geofisica applicata. Ognuna di queste branche della Geofisica ha avuto in passato uno sviluppo quasi del tutto indipendente con collaborazioni o integrazioni dirtte ad obiettivi specifici, limitati anche nel tempo

  4. Kernel based subspace projection of hyperspectral images

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg; Arngren, Morten

    In hyperspectral image analysis an exploratory approach to analyse the image data is to conduct subspace projections. As linear projections often fail to capture the underlying structure of the data, we present kernel based subspace projections of PCA and Maximum Autocorrelation Factors (MAF...

  5. Geophysical Imaging of Fault Structures Over the Qadimah Fault, Saudi Arabia

    KAUST Repository

    AlTawash, Feras

    2011-06-01

    The purpose of this study is to use geophysical imaging methods to identify the conjectured location of the ‘Qadimah fault’ near the ‘King Abdullah Economic City’, Saudi Arabia. Towards this goal, 2-D resistivity and seismic surveys were conducted at two different locations, site 1 and site 2, along the proposed trace of the ‘Qadimah fault’. Three processing techniques were used to validate the fault (i) 2-D travel time tomography, (ii) resistivity imaging, and (iii) reflection trim stacking. The refraction traveltime tomograms at site 1 and site 2 both show low-velocity zones (LVZ’s) next to the conjectured fault trace. These LVZ’s are interpreted as colluvial wedges that are often observed on the downthrown side of normal faults. The resistivity tomograms are consistent with this interpretation in that there is a significant change in resistivity values along the conjectured fault trace. Processing the reflection data did not clearly reveal the existence of a fault, and is partly due to the sub-optimal design of the reflection experiment. Overall, the results of this study strongly, but not definitively, suggest the existence of the Qadimah fault in the ‘King Abdullah Economic City’ region of Saudi Arabia.

  6. Turnover Time in the Hyporheic Zone as Assessed by 3D Geophysical Imaging

    Science.gov (United States)

    Kohler, B.; Hall, R. O., Jr.; Carr, B.

    2017-12-01

    The hyporheic zone (HZ) is a region of interest in stream hydrology and ecology, however, its heterogeneity across small spatial scales and difficulty to directly measure has hampered researchers' efforts to understand its specific contribution to processes such as solute transport and nutrient retention and removal. In recent years researchers have combined geophysical imaging, such as electrical resistivity tomography (ERT), with tracer additions to directly measure exchange between surface waters and the HZ without physically disrupting natural subsurface flow paths. We conducted constant-rate tracer additions in two small headwater mountain streams while collecting 3D ERT images downstream before, during, after each tracer addition to yield spatially comprehensive models of solute exchange with the HZ through time. From our 3D HZ models, we calculated the active volume of the HZ, normalized to the maximum measured size, for each time step giving a breakthrough curve of tracer abundance in the HZ through time. We then described the tracer's turnover time in the HZ by applying exponential and power decay models to the breakthrough curve of HZ volume in a similar manner that one would for a tracer breakthrough curve in surface waters. Our models suggest that the flushing of solutes from the HZ exhibit multi-domain behavior, where advective and diffusive exchange between HZ and surface waters occur simultaneously and operate at distinctly different rates.

  7. Geophysical logging and thermal imaging near the Hemphill Road TCE National Priorities List Superfund site near Gastonia, North Carolina

    Science.gov (United States)

    Antolino, Dominick J.; Chapman, Melinda J.

    2017-03-27

    Borehole geophysical logs and thermal imaging data were collected by the U.S. Geological Survey near the Hemphill Road TCE (trichloroethylene) National Priorities List Superfund site near Gastonia, North Carolina, during August 2014 through February 2015. In an effort to assist the U.S. Environmental Protection Agency in the development of a conceptual groundwater model for the assessment of current contaminant distribution and future migration of contaminants, surface geological mapping and borehole geophysical log and thermal imaging data collection, which included the delineation of more than 600 subsurface features (primarily fracture orientations), was completed in five open borehole wells and two private supply bedrock wells. In addition, areas of possible groundwater discharge within a nearby creek downgradient of the study site were determined based on temperature differences between the stream and bank seepage using thermal imagery.

  8. Integrated geophysical imaging of the Aluto-Langano geothermal field (Ethiopia).

    Science.gov (United States)

    Rizzello, Daniele; Armadillo, Egidio; Verdoya, Massimo; Pasqua, Claudio; Kebede, Solomon; Mengiste, Andarge; Hailegiorgis, Getenesh; Abera, Fitsum; Mengesha, Kebede; Meqbel, Naser

    2017-04-01

    The Aluto-Langano geothermal system is located in the central part of the Main Ethiopian Rift, one of the world's most tectonically active areas, where continental rifting has been occurring since several Ma and has yielded widespread volcanism and enhanced geothermal gradient. The geothermal system is associated to the Mt Aluto Volcanic Complex, located along the eastern margin of the rift and related to the Wonji Fault Belt, constituted by Quaternary NNE-SSW en-echelon faults. These structures are younger than the NE-SW border faults of the central Main Ethiopian Rift and were originated by a stress field oblique to the rift direction. This peculiar tectonism yielded local intense rock fracturing that may favour the development of geothermal reservoirs. In this paper, we present the results of an integrated geophysical survey carried out in 2015 over an area of about 200 km2 covering the Mt Aluto Volcanic Complex. The geophysical campaign included 162 coincident magnetotelluric and time domain electromagnetic soundings, and 207 gravity stations, partially located in the sedimentary plain surrounding the volcanic complex. Three-dimensional inversion of the full MT static-corrected tensor and geomagnetic tipper was performed in the 338-0.001 Hz band. Gravity data processing comprised digital enhancement of the residual Bouguer anomaly and 2D-3D inverse modelling. The geophysical results were compared to direct observations of stratigraphy, rock alteration and temperature available from the several deep wells drilled in the area. The magnetotelluric results imaged a low-resistivity layer which appears well correlated with the mixed alteration layer found in the wells and can be interpreted as a low-temperature clay cap. The clay-cap bottom depth is well corresponds to a change of thermal gradient. The clay cap is discontinuous, and in the central area of the volcanic complex is characterised by a dome-shape structure likely related to isotherm rising. The propilitic

  9. The QuakeSim Project: Web Services for Managing Geophysical Data and Applications

    Science.gov (United States)

    Pierce, Marlon E.; Fox, Geoffrey C.; Aktas, Mehmet S.; Aydin, Galip; Gadgil, Harshawardhan; Qi, Zhigang; Sayar, Ahmet

    2008-04-01

    We describe our distributed systems research efforts to build the “cyberinfrastructure” components that constitute a geophysical Grid, or more accurately, a Grid of Grids. Service-oriented computing principles are used to build a distributed infrastructure of Web accessible components for accessing data and scientific applications. Our data services fall into two major categories: Archival, database-backed services based around Geographical Information System (GIS) standards from the Open Geospatial Consortium, and streaming services that can be used to filter and route real-time data sources such as Global Positioning System data streams. Execution support services include application execution management services and services for transferring remote files. These data and execution service families are bound together through metadata information and workflow services for service orchestration. Users may access the system through the QuakeSim scientific Web portal, which is built using a portlet component approach.

  10. High-frequency HYDRO-geophysical observations for an advanced understanding of clayey landSLIDES: the HYDROSLIDE research project

    Science.gov (United States)

    Malet, Jean-Philippe; Supper, Robert; Flores-Orozco, Adrian; Gautier, Stéphanie; Bogaard, Thom

    2017-04-01

    As a consequence of change in hydrological cycles and the increase of exposed goods, the risk of landslides is globally growing all over the world. As a consequence, short-time landslide prediction is a fundamental tool for risk mitigation. To this aim, real-time monitoring and interpretation methods aiming at a full exploitation of the available landslide information are needed, including further development of sensor technology and use of advanced numerical modeling. The most commonly used warning parameters are direct measurements of slope displacement and pore-water pressures. However, recent research on landslide controlled by slope hydrology has shown that other parameters (e.g. soil moisture) can be used and other methods (e.g. electrical resistivity tomography, electrical spontaneous potential) are available, which might give indications on triggering even before an actual displacement is measureable and thus could possibly be used as physical precursors for short-term warning. The CNRS - Ecole et Observatoire des Sciences de la Terre (EOST) and the Geological Survey of Austria - Geophysical Division (GBA) started successfully to evaluate time-lapse resistivity measurements for monitoring changes in water content/flows in landslides at different monitoring sites. At the same period, CNRS also started to establish the French Observatory on Landslides (OMIV: omiv.unistra.fr), which task is the long term monitoring and data sharing of landslide parameters (geodesy, hydrology, seismic). Results from these projects proved that electrical resistivity monitoring can be successfully applied to detect changes in water storage and to understand water circulation in complex landslide bodies. However, especially for clayey landslides, this method is only applicable with limitation, since the resistivity of clays shows almost the same values as the resistivity of the saturated soil (15-20 O.m). Consequently, the change in water content expressed in the electrical

  11. Discriminative Projection Selection Based Face Image Hashing

    Science.gov (United States)

    Karabat, Cagatay; Erdogan, Hakan

    Face image hashing is an emerging method used in biometric verification systems. In this paper, we propose a novel face image hashing method based on a new technique called discriminative projection selection. We apply the Fisher criterion for selecting the rows of a random projection matrix in a user-dependent fashion. Moreover, another contribution of this paper is to employ a bimodal Gaussian mixture model at the quantization step. Our simulation results on three different databases demonstrate that the proposed method has superior performance in comparison to previously proposed random projection based methods.

  12. Geophysical logging and imaging of shallow drillholes ONK-PP262 and ONK-274 at Olkiluoto in 2010

    International Nuclear Information System (INIS)

    Tarvainen, A.-M.

    2011-11-01

    Suomen Malmi Oy conducted geophysical drillhole logging as well as optical and acoustic imaging of shallow drillholes ONK-PP262 and ONK-PP274 at ONKALO in the investigation niche ONK-TKU-4 (Hydco) in May and in December 2010. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  13. Geophysical logging and imaging of characterisation drillholes ONK-KR13, ONK-KR14 and ONK-KR15

    International Nuclear Information System (INIS)

    Tarvainen, A.-M.

    2011-08-01

    Suomen Malmi Oy conducted geophysical drillhole logging as well as optical and acoustic imaging of drillholes ONK-KR13, ONK-KR14 and ONK-KR15 at ONKALO in June-July 2010 and in March 2011. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  14. Objective computerized approaches for centralized geophysical and geochemical landscape project planning.

    Directory of Open Access Journals (Sweden)

    Danilyan Eugene Andreevich

    2013-10-01

    Full Text Available At present landscape design does not represent a scientific subject in strict sense, being a superposition of decorative and applied landscape art and the methods of graphic architectural planning. Serving interests of customers, it does not harmonize with the individual needs of the ground based on landscape geochemistry and ecology. Hence, it results in great number of grounds not consistent with each other according to geochemical criteria. In many cases total soil changing, isolation of natural hydrodynamic drainage, introduction of exotic plants interacting with their environment (including abiotic relations take place, it results in disequilibrium in the ground. Ecological system efficiency needs to be constantly artificially maintained, and that does not support its stability. In other words, without maintaining sufficient conditions, it will be influenced by succession with the course of time, as a particular case of potential gradient equalization. Hence, at present there is an acute problem to develop such a concept of landscape design, that, covering ecological requirements of customers, would be mass one, not producing gradient isolation effect and ecologically self-sustaining in given environment at the same time. It is evident, that to meet these requirements, this concept should not be the product of subjective vision of the author, but direct consequence of geophysical and geochemical landscape condition with theoretical development allowing calculation testing at any scale of geographical zoning.

  15. Near real-time imaging of molasses injections using time-lapse electrical geophysics at the Brandywine DRMO, Brandywine, Maryland

    Science.gov (United States)

    Versteeg, R. J.; Johnson, T.; Major, B.; Day-Lewis, F. D.; Lane, J. W.

    2010-12-01

    Enhanced bioremediation, which involves introduction of amendments to promote biodegradation, increasingly is used to accelerate cleanup of recalcitrant compounds and has been identified as the preferred remedial treatment at many contaminated sites. Although blind introduction of amendments can lead to sub-optimal or ineffective remediation, the distribution of amendment throughout the treatment zone is difficult to measure using conventional sampling. Because amendments and their degradation products commonly have electrical properties that differ from those of ambient soil, time-lapse electrical geophysical monitoring has the potential to verify amendment emplacement and distribution. In order for geophysical monitoring to be useful, however, results of the injection ideally should be accessible in near real time. In August 2010, we demonstrated the feasibility of near real-time, autonomous electrical geophysical monitoring of amendment injections at the former Defense Reutilization and Marketing Office (DRMO) in Brandywine, Maryland. Two injections of about 1000 gallons each of molasses, a widely used amendment for enhanced bioremediation, were monitored using measurements taken with borehole and surface electrodes. During the injections, multi-channel resistance data were recorded; data were transmitted to a server and processed using a parallel resistivity inversion code; and results in the form of time-lapse imagery subsequently were posted to a website. This process occurred automatically without human intervention. The resulting time-lapse imagery clearly showed the evolution of the molasses plume. The delay between measurements and online delivery of images was between 45 and 60 minutes, thus providing actionable information that could support decisions about field procedures and a check on whether amendment reached target zones. This experiment demonstrates the feasibility of using electrical imaging as a monitoring tool both during amendment emplacement

  16. Geological modeling and infiltration pattern of a karstic system based upon crossed geophysical methods and image-guided inversion

    Science.gov (United States)

    Duran, Lea; Jardani, Abderrahim; Fournier, Matthieu; Massei, Nicolas

    2015-04-01

    Karstic aquifers represent an important part of the water resources worldwide. Though they have been widely studied on many aspects, their geological and hydrogeological modeling is still complex. Geophysical methods can provide useful subsurface information for the characterization and mapping of karstic systems, especially when not accessible by speleology. The site investigated in this study is a sinkhole-spring system, with small diameter conduits that run within a chalk aquifer (Norville, in Upper Normandy, France). This site was investigated using several geophysical methods: electrical tomography, self-potential, mise-à-la-masse methods, and electromagnetic method (EM34). Coupling those results with boreholes data, a 3D geological model of the hydrogeological basin was established, including tectonic features as well as infiltration structures (sinkhole, covered dolines). The direction of the karstic conduits near the main sinkhole could be established, and the major fault was shown to be a hydraulic barrier. Also the average concentration of dolines on the basin could be estimated, as well as their depth. At last, several hypotheses could be made concerning the location of the main conduit network between the sinkhole and the spring, using previous hydrodynamic study of the site along with geophysical data. In order to validate the 3D geological model, an image-guided inversion of the apparent resistivity data was used. With this approach it is possible to use geological cross sections to constrain the inversion of apparent resistivity data, preserving both discontinuities and coherences in the inversion of the resistivity data. This method was used on the major fault, enabling to choose one geological interpretation over another (fault block structure near the fault, rather than important folding). The constrained inversion was also applied on covered dolines, to validate the interpretation of their shape and depth. Key words: Magnetic and electrical

  17. Two-step web-mining approach to study geology/geophysics-related open-source software projects

    Science.gov (United States)

    Behrends, Knut; Conze, Ronald

    2013-04-01

    Geology/geophysics is a highly interdisciplinary science, overlapping with, for instance, physics, biology and chemistry. In today's software-intensive work environments, geoscientists often encounter new open-source software from scientific fields that are only remotely related to the own field of expertise. We show how web-mining techniques can help to carry out systematic discovery and evaluation of such software. In a first step, we downloaded ~500 abstracts (each consisting of ~1 kb UTF-8 text) from agu-fm12.abstractcentral.com. This web site hosts the abstracts of all publications presented at AGU Fall Meeting 2012, the world's largest annual geology/geophysics conference. All abstracts belonged to the category "Earth and Space Science Informatics", an interdisciplinary label cross-cutting many disciplines such as "deep biosphere", "atmospheric research", and "mineral physics". Each publication was represented by a highly structured record with ~20 short data attributes, the largest authorship-record being the unstructured "abstract" field. We processed texts of the abstracts with the statistics software "R" to calculate a corpus and a term-document matrix. Using R package "tm", we applied text-mining techniques to filter data and develop hypotheses about software-development activities happening in various geology/geophysics fields. Analyzing the term-document matrix with basic techniques (e.g., word frequencies, co-occurences, weighting) as well as more complex methods (clustering, classification) several key pieces of information were extracted. For example, text-mining can be used to identify scientists who are also developers of open-source scientific software, and the names of their programming projects and codes can also be identified. In a second step, based on the intermediate results found by processing the conference-abstracts, any new hypotheses can be tested in another webmining subproject: by merging the dataset with open data from github

  18. Developing geophysical monitoring at Mayon volcano, a collaborative project EOS-PHIVOLCS

    Science.gov (United States)

    Hidayat, D.; Laguerta, E.; Baloloy, A.; Valerio, R.; Marcial, S. S.

    2011-12-01

    Mayon is an openly-degassed volcano, producing mostly small, frequent eruptions, most recently in Aug-Sept 2006 and Dec 2009. Mayon volcano status is level 1 with low seismicity dominated mostly local and regional tectonic earthquakes with continuous emission of SO2 from its crater. A research collaboration between Earth Observatory of Singapore-NTU and Philippine Institute of Volcanology and Seismology (PHIVOLCS) have been initiated in 2010 with effort to develop a multi-disciplinary monitoring system around Mayon includes geophysical monitoring, gas geochemical monitoring, and petrologic studies. Currently there are 4 broadband seismographs, 3 short period instruments, and 4 tiltmeters. These instruments will be telemetered to the Lignon Hill Volcano Observatory through radio and 3G broadband internet. We also make use of our self-made low-cost datalogger which has been operating since Jan 2011, performing continuous data acquisition with sampling rate of 20 minute/sample and transmitted through gsm network. First target of this monitoring system is to obtain continuous multi parameter data transmitted in real time to the observatory from different instruments. Tectonically, Mayon is located in the Oas Graben, a northwest-trending structural depression. Previous study using InSAR data, showing evidence of a left-lateral oblique slip movement of the fault North of Mayon. Understanding on what structures active deformation is occurring and how deformation signal is currently partitioned between tectonic and volcanic origin is a key for characterizing magma movement in the time of unrest. Preliminary analysis of the tangential components of tiltmeters (particularly the stations 5 and 7.5 NE from the volcano) shows gradual inflation movement over a few months period. The tangential components for tiltmeters are roughly perpendicular to the fault north of Mayon. This may suggest downward tilting of the graben in the northern side of Mayon. Another possibility is that

  19. Evaluation of geologic and geophysical techniques for surface-to-subsurface projections of geologic characteristics in crystalline rock

    International Nuclear Information System (INIS)

    1985-07-01

    Granitic and gneissic rock complexes are being considered for their potential to contain and permanently isolate high-level nuclear waste in a deep geologic repository. The use of surface geologic and geophysical techniques has several advantages over drilling and testing methods for geologic site characterization in that the techniques are typically less costly, provide data over a wider area, and do not jeopardize the physical integrity of a potential repository. For this reason, an extensive literature review was conducted to identify appropriate surface geologic and geophysical techniques that can be used to characterize geologic conditions in crystalline rock at proposed repository depths of 460 to 1,220 m. Characterization parameters such as rock quality; fracture orientation, spacing; and aperture; depths to anomalies; degree of saturation; rock body dimensions; and petrology are considered to be of primary importance. Techniques reviewed include remote sensing, geologic mapping, petrographic analysis, structural analysis, gravity and magnetic methods, electrical methods, and seismic methods. Each technique was reviewed with regard to its theoretical basis and field application; geologic parameters that can be evaluated; advantages and limitations, and, where available, case history applications in crystalline rock. Available information indicates that individual techniques provide reliable information on characteristics at the surface, but have limited success in projections to depths greater that approximately 100 m. A combination of integrated techniques combines with data from a limited number of boreholes would significantly improve the reliability and confidence of early characterization studies to provide qualitative rock body characteristics for region-to-area and area-to-site selection evaluations. 458 refs., 32 figs., 14 tabs

  20. Medical imaging projects meet at CERN

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    ENTERVISION, the Research Training Network in 3D Digital Imaging for Cancer Radiation Therapy, successfully passed its mid-term review held at CERN on 11 January. This multidisciplinary project aims at qualifying experts in medical imaging techniques for improved hadron therapy.   ENTERVISION provides training in physics, medicine, electronics, informatics, radiobiology and engineering, as well as a wide range of soft skills, to 16 researchers of different backgrounds and nationalities. The network is funded by the European Commission within the Marie Curie Initial Training Network, and relies on the EU-funded research project ENVISION to provide a training platform for the Marie Curie researchers. The two projects hold their annual meetings jointly, allowing the young researchers to meet senior scientists and to have a full picture of the latest developments in the field beyond their individual research project. ENVISION and ENTERVISION are both co-ordinated by CERN, and the Laboratory hosts t...

  1. Geophysical borehole logging, dummy-sonding and optical imaging of the borehole OL-KR24 at Olkiluoto 2005

    International Nuclear Information System (INIS)

    Majapuro, J.

    2006-03-01

    Suomen Malmi Oy conducted geophysical borehole logging, dummy-sonding and optical imaging surveys of the borehole OL-KR24 at the Olkiluoto site in Eurajoki during 1.10.2005 - 4.10.2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are caliper survey and optical imaging. The assignment included the field work of surveys, interpretation and processing of the data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

  2. Geophysical borehole logging and optical imaging of the boreholes KR34, KR35 and KR36, at Olkiluoto 2005

    Energy Technology Data Exchange (ETDEWEB)

    Majapuro, J. [Suomen Malmi Oy, Espoo (Finland)

    2005-09-15

    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of the boreholes KR34, KR35 and KR36 at the Olkiluoto site in Eurajoki during May - June 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all surveys, interpretation and processing of the acoustic and borehole radar data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

  3. Geophysical borehole logging and optical imaging of the boreholes KR34, KR35 and KR36, at Olkiluoto 2005

    International Nuclear Information System (INIS)

    Majapuro, J.

    2005-09-01

    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of the boreholes KR34, KR35 and KR36 at the Olkiluoto site in Eurajoki during May - June 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all surveys, interpretation and processing of the acoustic and borehole radar data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

  4. Contribution of geophysical methods to the detection of underground cavities in salt series. Development in different projects in Morocco (roads, rail, etc…

    Directory of Open Access Journals (Sweden)

    Tlemçani M.K.

    2018-01-01

    Full Text Available As part of the geotechnical studies of a road project, a geophysical investigation by electrical tomography, microgravimetry, and boreholes, was carried out in order to locate if the areas can present or not a risks of ground instability along the road alignment. The road is located near a rock salt mine. This geophysical survey had demonstrated that the area may present major risks for the stability of the road platform. This risk is related to the existence of large expanses of saliferous rocks.The dissolution and exploitation of salt provoked underground voids under the future road. The results of this geophysical survey have allowed the designer office to propose more suitable solutions to solve this problem or even the possibility of shifting another site.

  5. Petroleum geophysics

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    The book is compiled from a series of e-learning modules. GeoCLASS is an e-learning system with contents from petroleum geophysics. It is the result of collaboration between professors at the University of Bergen and the University of Oslo, and its material has been used as curriculum in master program courses at these universities for several years. Using a unique feature to GeoCLASS, these advanced scientific topics are presented on multiple levels. The introductions open the door to this vast pool of knowledge, accessible even for high school students. Enter the door, and you enter the modules. Various levels of content are presented, and the more advanced levels can be shielded from the regular user, and only accessed by those with particular interest. The chapters in the book are: Elastic waves; Survey planning; Seismic acquisition; Basic seismic signal theory and processing; Seismic imaging; Seismic attributes; Rock physics; Reservoir monitoring. (AG)

  6. Projection x-space magnetic particle imaging.

    Science.gov (United States)

    Goodwill, Patrick W; Konkle, Justin J; Zheng, Bo; Saritas, Emine U; Conolly, Steven M

    2012-05-01

    Projection magnetic particle imaging (MPI) can improve imaging speed by over 100-fold over traditional 3-D MPI. In this work, we derive the 2-D x-space signal equation, 2-D image equation, and introduce the concept of signal fading and resolution loss for a projection MPI imager. We then describe the design and construction of an x-space projection MPI scanner with a field gradient of 2.35 T/m across a 10 cm magnet free bore. The system has an expected resolution of 3.5 × 8.0 mm using Resovist tracer, and an experimental resolution of 3.8 × 8.4 mm resolution. The system images 2.5 cm × 5.0 cm partial field-of views (FOVs) at 10 frames/s, and acquires a full field-of-view of 10 cm × 5.0 cm in 4 s. We conclude by imaging a resolution phantom, a complex "Cal" phantom, mice injected with Resovist tracer, and experimentally confirm the theoretically predicted x-space spatial resolution.

  7. Analysis of geophysical well logs from the Mariano Lake-Lake Valley drilling project, San Juan Basin, Northwestern New Mexico

    International Nuclear Information System (INIS)

    Scott, J.H.

    1986-01-01

    Geophysical well logs were obtained in eight deep holes drilled and cored by the U.S. Geological Survey to examine the geology of the Mariano Lake-Lake Valley area in the southern part of the San Juan basin, New Mexico. The logs were made to determine the petrophysical properties of the rocks penetrated by the holes, to aid in making stratigraphic correlations between the holes, and to estimate the grade of uranium enrichment in mineralized zones. The logs can be divided into six categories-nuclear, electric, sonic, magnetic, dipmeter, and borehole conditions. Examples of these logs are presented and related to lithological and petrophysical properties of the cores recovered. Gamma-ray and prompt fission neutron logs were used to estimate uranium grade in mineralized zones. Resistivity and spontaneous potential logs were used to make stratigraphic correlations between drill holes and to determine the variability of the sandstone:mudstone ratios of the major sedimentary units. In one drill hole a dipmeter log was used to estimate the direction of sediment transport of the fluvial host rock. Magnetic susceptibility logs provided supportive information for a laboratory study of magnetic mineral alteration in drill cores. This study was used to infer the geochemical and hydrologic environment associated with uranium deposition in the project area

  8. Imaging normal faults in alluvial fans using geophysical techniques: Field example from the coast of Gulf of Aqaba, Saudi Arabia

    KAUST Repository

    Hanafy, Sherif M.

    2014-08-05

    In this work we use geophysical methods to locate and characterize active faults in alluvial sediments. Since only subtle material and velocity contrasts are expected across the faults, we used seismic refraction tomography and 2D resistivity imaging to locate the fault. One seismic profile and one 2D resistivity profile are collected at an alluvial fan on the Gulf of Aqaba coast in Saudi Arabia. The collected data are inverted to generate the traveltime tomogram and the electric resistivity tomogram (ERT). A low velocity anomaly is shown on the traveltime tomogram indicates the colluvial wedge associated with the fault. The location of the fault is shown on the ERT as a vertical high resistivity anomaly.

  9. Information and image integration: project spectrum

    Science.gov (United States)

    Blaine, G. James; Jost, R. Gilbert; Martin, Lori; Weiss, David A.; Lehmann, Ron; Fritz, Kevin

    1998-07-01

    The BJC Health System (BJC) and the Washington University School of Medicine (WUSM) formed a technology alliance with industry collaborators to develop and implement an integrated, advanced clinical information system. The industry collaborators include IBM, Kodak, SBC and Motorola. The activity, called Project Spectrum, provides an integrated clinical repository for the multiple hospital facilities of the BJC. The BJC System consists of 12 acute care hospitals serving over one million patients in Missouri and Illinois. An interface engine manages transactions from each of the hospital information systems, lab systems and radiology information systems. Data is normalized to provide a consistent view for the primary care physician. Access to the clinical repository is supported by web-based server/browser technology which delivers patient data to the physician's desktop. An HL7 based messaging system coordinates the acquisition and management of radiological image data and sends image keys to the clinical data repository. Access to the clinical chart browser currently provides radiology reports, laboratory data, vital signs and transcribed medical reports. A chart metaphor provides tabs for the selection of the clinical record for review. Activation of the radiology tab facilitates a standardized view of radiology reports and provides an icon used to initiate retrieval of available radiology images. The selection of the image icon spawns an image browser plug-in and utilizes the image key from the clinical repository to access the image server for the requested image data. The Spectrum system is collecting clinical data from five hospital systems and imaging data from two hospitals. Domain specific radiology imaging systems support the acquisition and primary interpretation of radiology exams. The spectrum clinical workstations are deployed to over 200 sites utilizing local area networks and ISDN connectivity.

  10. Invisibility cloak with image projection capability.

    Science.gov (United States)

    Banerjee, Debasish; Ji, Chengang; Iizuka, Hideo

    2016-12-13

    Investigations of invisibility cloaks have been led by rigorous theories and such cloak structures, in general, require extreme material parameters. Consequently, it is challenging to realize them, particularly in the full visible region. Due to the insensitivity of human eyes to the polarization and phase of light, cloaking a large object in the full visible region has been recently realized by a simplified theory. Here, we experimentally demonstrate a device concept where a large object can be concealed in a cloak structure and at the same time any images can be projected through it by utilizing a distinctively different approach; the cloaking via one polarization and the image projection via the other orthogonal polarization. Our device structure consists of commercially available optical components such as polarizers and mirrors, and therefore, provides a significant further step towards practical application scenarios such as transparent devices and see-through displays.

  11. Inner structure of the Puy de Dôme volcano: cross-comparison of geophysical models (ERT, gravimetry, muon imaging

    Directory of Open Access Journals (Sweden)

    A. Portal

    2013-01-01

    Full Text Available Muon imaging of volcanoes and of geological structures in general is actively being developed by several groups in the world. It has the potential to provide 3-D density distributions with an accuracy of a few percent. At this stage of development, comparisons with established geophysical methods are useful to validate the method. An experiment has been carried out in 2011 and 2012 on a large trachytic dome, the Puy de Dôme volcano, to perform such a comparison of muon imaging with gravimetric tomography and 2-D electrical resistivity tomography. Here, we present the preliminary results for the last two methods. North–south and east–west resistivity profiles allow us to model the resistivity distribution down to the base of the dome. The modelling of the Bouguer anomaly provides models for the density distribution within the dome that are directly comparable with the results from the muon imaging. Our ultimate goal is to derive a model of the dome using the joint interpretation of all sets of data.

  12. Geochemical mapping in polluted floodplains using handheld XRF, geophysical imaging, and geostatistics

    Science.gov (United States)

    Hošek, Michal; Matys Grygar, Tomáš; Popelka, Jan; Kiss, Timea; Elznicová, Jitka; Faměra, Martin

    2017-04-01

    In the recent years researchers have enjoyed noticeable improvements of portable analytical and geophysical methods, which allow studying floodplain architecture and deciphering pollutant distribution more easily than ever before. Our area of interest was floodplain of the Ploučnice River, particularly a pollution hotspot in Boreček, severely impacted by U mining between the 1970s and late 1980s, in particular a "radioactive flood" in 1981. In the area, we used hand drill coring and in situ (field) analysis of so acquired sediments by handheld X-ray fluorescence spectrometer (XRF), which gave us information about depth profiles of pollutants (Ba, U, Zn) and the Al/Si and Zr/Rb ratios, i.e., proxies for sediment lithology. We found that spatial distribution of pollutants (control by depth and position in the floodplain) is apparently complex and discontinuous. In some places, contamination is buried by a couple decimetres of less polluted sediments, while in other places the peak pollution is near surface, apparently without a straightforward connection with the surface topography and the distance to the river channel. We thus examined the floodplain architecture, the internal structure of the floodplain using two geophysical methods. First of them, dipole electromagnetic profiling (DEMP, also denoted EMP, MP, or Slingram) quickly acquires average electric resistivity in top strata in selected areas, which was actually top 3 m with our particular instrument. Second, electric resistivity tomography (ERT) produces much more detailed information on resistivity with depth resolution of ca 0.5 m to the depth of ca 5 m in selected lines. ERT thus allows identifying boundaries of electric resistivity domains (sediment bodies) and DEMP their spatial distribution. Based on the obtained data, we divided the floodplain to five segments with specific topography, pollution characteristics, and electric resistivity. We suppose that those segments are lithogenetic floodplain

  13. Rapid, semi-automatic fracture and contact mapping for point clouds, images and geophysical data

    Science.gov (United States)

    Thiele, Samuel T.; Grose, Lachlan; Samsu, Anindita; Micklethwaite, Steven; Vollgger, Stefan A.; Cruden, Alexander R.

    2017-12-01

    The advent of large digital datasets from unmanned aerial vehicle (UAV) and satellite platforms now challenges our ability to extract information across multiple scales in a timely manner, often meaning that the full value of the data is not realised. Here we adapt a least-cost-path solver and specially tailored cost functions to rapidly interpolate structural features between manually defined control points in point cloud and raster datasets. We implement the method in the geographic information system QGIS and the point cloud and mesh processing software CloudCompare. Using these implementations, the method can be applied to a variety of three-dimensional (3-D) and two-dimensional (2-D) datasets, including high-resolution aerial imagery, digital outcrop models, digital elevation models (DEMs) and geophysical grids. We demonstrate the algorithm with four diverse applications in which we extract (1) joint and contact patterns in high-resolution orthophotographs, (2) fracture patterns in a dense 3-D point cloud, (3) earthquake surface ruptures of the Greendale Fault associated with the Mw7.1 Darfield earthquake (New Zealand) from high-resolution light detection and ranging (lidar) data, and (4) oceanic fracture zones from bathymetric data of the North Atlantic. The approach improves the consistency of the interpretation process while retaining expert guidance and achieves significant improvements (35-65 %) in digitisation time compared to traditional methods. Furthermore, it opens up new possibilities for data synthesis and can quantify the agreement between datasets and an interpretation.

  14. My Experience as a Student Participant in the Institute for Geophysics/Huston-Tillotson University Geodiversity Project

    Science.gov (United States)

    Putman, N.; Ellins, K.; Holt, J.; Olson, H. C.

    2006-12-01

    to "practice" for future human missions to Mars as a participant in NASA's Desert Research and Technology Studies (RATS) project. My role was to help scientists and engineers with experiments to determine the efficacy of Ground Penetrating Radar in locating buried ice (water) and other resources, such as metals, and to translate my experience into K-12 classroom activities. In the spring/summer of 2007 I expect to participate in a marine geophysical cruise offshore Panama and Costa Rica. The immersion in science, the opportunities to be part of scientific research teams, my daily interaction with scientists and graduate students, the mentoring from research scientists at UTIG, and the respect shown to me for transforming their science into interesting projects for K-12 students and teachers have been critical elements in my decision to pursue science teaching as a career.

  15. Integrated Geophysical Studies to Image the Remains of Amenemeht II Pyramid's Complex in Dahshour Necropolis, Giza, Egypt.

    Science.gov (United States)

    Abbas, Abbas Mohamed; Atya, Magdy; El-Emam, Ahmed; Ghazala, Hosny, ,, Prof.; Shaaban, Fathy, ,, Dr; Odah, Hatem, ,, Prof; Ibrahim, El-Khedr, ,, Prof; Lethy, Ahmed, ,, Dr

    2009-04-01

    Dahshour archaeological site is located adjacent to Giza necropolis at about 25 km south of Cairo. The site itself is an imperative necropolis that attracts the attention of the archaeologists. This location is a spectator of several historical episodes that start with the pyramidal complexes from the early dynasties (the mud brick tombs, the mastabas, and the Bent Pyramid) passing through the phase of the Step Pyramid of Zoser at Saqqara to the first complete pyramid in the history (the Red pyramid of Senefro "Khofo's father"). In 2002, the local archaeological supervisors suggested an area around the debris of the White pyramid (of Amenemeht II) for reconnaissance magnetic survey. The survey had been completed using the gradiometer FM36. More than 98 survey grids (20 x 20 m) of a surface area of 39200 m2 have been measured. The results reported the recognition of some parts of the mortuary temple, the causeway, and some other anomalies that could not be attributed to specific archaeological aspect. Therefore, an integrated geophysical survey was proposed, in the present work, to get more details help to identify these objects. The ground penetrating radar (GPR, SIR2000), the electrical resistance meter (Geoscan RM15), and the electromagnetic profiler (GEM300) have been utilized to acquire the data. They have been applied to selected zones to investigate specific objects and oriented to solve the problems questioned by the local archaeological inspectors. The study conveyed an superior image of the whole measured site and helped to identify most of the detected artifacts. Furthermore, the margins of the causeway and its infrastructure have been perfectly delineated. However, the possible place of the eastern entrance and the Valley temple have been tentatively located. Keywords: Archaeo-geophysics, Dahshour, White Pyramid

  16. Geophysical and geochemical processing of data from the Santa Terezinha de Goias region, Brazil

    International Nuclear Information System (INIS)

    Calle, Carlos Humberto Tapia; Pires, A.C.B.

    1995-01-01

    The paper presents a few data processing techniques used with geophysical and geometry data from Santa Terezinha de Goias. Airborne gamma ray spectrometry and magnetometry were conduced in the area during the Brazil Canada Geophysical Project. Black and white and color images produced using available procedures resulted in new interpretation for the geological mapping. Guidelines for emerald exploration in the area are suggested from images and anomalous potassium map. (author). 14 refs., 5 figs

  17. Cyclicity, episodicity, and continuity in accretionary wedge evolution: insights from geophysical imaging and physical analogue experiments

    Science.gov (United States)

    Kukowski, N.

    2009-04-01

    Geophysical profiles across active convergent margins reveal different styles and locations of sediment accretion, thrust slices dipping successively steeper towards the hinterland, splay faults, and blind thrusts as well as accumulation spaces e. g. thrust top basins and larger basins formed by regional subsidence, of very variable size and position. Morphologically, the continental slope at most margins can be sub-divided in a lower, middle, and upper slope, with often the middle slope being the most shallowly inclined, suggesting segmented wedges. Beneath the forearc, a subduction channel of a few hundred meters to a few km thickness marks a layer of material transport into greater depth that also hosts the plate interface and décollement zone. The petrographical composition of accretionary wedges and subduction channels as well as related pressures and temperatures are accessible through deep drilling or sampling fossil accretionary complexes now exhumed. The structure, lithology, and tectonic history of forearcs as identified from geophysical and geology field observations hint to parameters possibly controlling material transfer at convergent margins. Among them, sediment supply, which itself is largely controlled by climate, width of the subduction channel, and interplate frictional properties, which also exhibit control on plate coupling and therefore the seismic potential of a forearc, are suggested to be of major importance. These parameters further may undergo temporal fluctuation, e.g. when climate changes or when different material is entering the trench and therefore potentially also the subduction channel. High resolution monitoring of material flux and the evolution of fault zone kinematics of analogue experimental wedges made of granular materials exhibiting frictional behaviour equivalent to that of upper crustal rocks shows that accretionary cycles proceed as a chain of sub-processes, i.e. the development of a thrust slice from initial failure

  18. Geology, geochemistry, and geophysics of the Fry Canyon uranium/copper project site, southeastern Utah - Indications of contaminant migration

    Science.gov (United States)

    Otton, James K.; Zielinski, Robert A.; Horton, Robert J.

    2010-01-01

    The Fry Canyon uranium/copper project site in San Juan County, southeastern Utah, was affected by the historical (1957-68) processing of uranium and copper-uranium ores. Relict uranium tailings and related ponds, and a large copper heap-leach pile at the site represent point sources of uranium and copper to local soils, surface water, and groundwater. This study was designed to establish the nature, extent, and pathways of contaminant dispersion. The methods used in this study are applicable at other sites of uranium mining, milling, or processing. The uranium tailings and associated ponds sit on a bench that is as much as 4.25 meters above the level of the adjacent modern channel of Fry Creek. The copper heap leach pile sits on bedrock just south of this bench. Contaminated groundwater from the ponds and other nearby sites moves downvalley and enters the modern alluvium of adjacent Fry Creek, its surface water, and also a broader, deeper paleochannel that underlies the modern creek channel and adjacent benches and stream terraces. The northern extent of contaminated groundwater is uncertain from geochemical data beyond an area of monitoring wells about 300 meters north of the site. Contaminated surface water extends to the State highway bridge. Some uranium-contaminated groundwater may also enter underlying bedrock of the Permian Cedar Mesa Sandstone along fracture zones. Four dc-resistivity surveys perpendicular to the valley trend were run across the channel and its adjacent stream terraces north of the heap-leach pile and ponds. Two surveys were done in a small field of monitoring wells and two in areas untested by borings to the north of the well field. Bedrock intercepts, salt distribution, and lithologic information from the wells and surface observations in the well field aided interpretation of the geophysical profiles there and allowed interpretation of the two profiles not tested by wells. The geophysical data for the two profiles to the north of the

  19. Image-projection ion-beam lithography

    International Nuclear Information System (INIS)

    Miller, P.A.

    1989-01-01

    Image-projection ion-beam lithography is an attractive alternative for submicron patterning because it may provide high throughput; it uses demagnification to gain advantages in reticle fabrication, inspection, and lifetime; and it enjoys the precise deposition characteristics of ions which cause essentially no collateral damage. This lithographic option involves extracting low-mass ions (e.g., He + ) from a plasma source, transmitting the ions at low voltage through a stencil reticle, and then accelerating and focusing the ions electrostatically onto a resist-coated wafer. While the advantages of this technology have been demonstrated experimentally by the work of IMS (Austria), many difficulties still impede extension of the technology to the high-volume production of microelectronic devices. We report a computational study of a lithography system designed to address problem areas in field size, telecentricity, and chromatic and geometric aberration. We present a novel ion-column-design approach and conceptual ion-source and column designs which address these issues. We find that image-projection ion-beam technology should in principle meet high-volume-production requirements. The technical success of our present relatively compact-column design requires that a glow-discharge-based ion source (or equivalent cold source) be developed and that moderate further improvement in geometric aberration levels be obtained. Our system requires that image predistortion be employed during reticle fabrication to overcome distortion due to residual image nonlinearity and space-charge forces. This constitutes a software data preparation step, as do correcting for distortions in electron lithography columns and performing proximity-effect corrections. Areas needing further fundamental work are identified

  20. Ultrasonic imaging of projected components of PFBR

    Energy Technology Data Exchange (ETDEWEB)

    Sylvia, J.I., E-mail: sylvia@igcar.gov.in [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India); Jeyan, M.R.; Anbucheliyan, M.; Asokane, C.; Babu, V. Rajan; Babu, B.; Rajan, K.K.; Velusamy, K.; Jayakumar, T. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu (India)

    2013-05-15

    Highlights: ► Under sodium ultrasonic scanner in PFBR is for detecting protruding objects. ► Feasibility study for detecting Absorber rods and its drive mechanisms. ► Developed in-house PC based ultrasonic imaging system. ► Different case studies were carried out on simulated ARDM's. ► Implemented the experimental results to PFBR application. -- Abstract: The 500 MWe, sodium cooled, Prototype Fast Breeder Reactor (PFBR) is under advanced stage of construction at Kalpakkam in India. Opacity of sodium restricts visual inspection of components immersed in sodium by optical means. Ultrasonic wave passes through sodium hence ultrasonic techniques using under sodium ultrasonic scanners are developed to obtain under sodium images. The main objective of such an Under Sodium Ultrasonic Scanner (USUSS) for Prototype Fast Breeder Reactor (PFBR) is to detect and ensure that no core Sub Assembly (SA) or Absorber Rod or its Drive Mechanism is protruded in the above core plenum before starting the fuel handling operation. Hence, it is necessary to detect and locate the object, if it is protruding the above core plenum. To study the feasibility of detecting the absorber rods and their drive mechanisms using direct ultrasonic imaging technique, experiments were carried out for different orientations and profiles of the projected components in a 5 m diameter water tank. The in-house developed PC based ultrasonic scanning system is used for acquisition and analysis of data. The pseudo three dimensional color images obtained are discussed and the results are applicable for PFBR. This paper gives the details of the features of the absorber rods and their drive mechanisms, their orientation in the reactor core, experimental setup, PC based ultrasonic scanning system, ultrasonic images and the discussion on the results.

  1. The Chinese Cretaceous Continental Scientific Drilling Project in the Songliao Basin, NE China: Organic-rich source rock evaluation with geophysical logs from Borehole SK-2

    Science.gov (United States)

    Zhang, X.; Zou, C.

    2017-12-01

    The Cretaceous strata have been recognized as an important target of oil or gas exploration in the Songliao Basin, northeast China. The second borehole (SK-2) of the Chinese Cretaceous Continental Scientific Drilling Project in the Songliao Basin (CCSD-SK) is the first one to drill through the Cretaceous continental strata in the frame of ICDP. It was designed not only to solve multiple scientific problems (including the Cretaceous paleoenvironment and paleoclimate, as well as deep resources exploration of the Songliao Basin), but also to expect to achieve new breakthroughs in oil and gas exploration. Based on the project, various geophysical log data (including gamma, sonic, resistivity, density etc.) and core samples have been collected from Borehole SK-2. We do research on organic-rich source rocks estimation using various geophysical log data. Firstly, we comprehensively analyzed organic-rich source rocks' geophysical log response characteristics. Then, source rock's identification methods were constructed to identify organic-rich source rocks with geophysical logs. The main identification methods include cross-plot, multiple overlap and Decision Tree method. Finally, the technique and the CARBOLOG method were applied to evaluate total organic carbon (TOC) content from geophysical logs which provide continuous vertical profile estimations (Passey, 1990; Carpentier et al., 1991). The results show that source rocks are widely distributed in Borehole SK-2, over a large depth strata (985 5700m), including Nenjiang, Qingshankou, Denglouku, Yingcheng, Shahezi Formations. The organic-rich source rocks with higher TOC content occur in the Qingshankou (1647 1650m), Denglouku (2534 2887m) and Shahezi (3367 5697m) Formations. The highest TOC content in these formations can reach 10.31%, 6.58%, 12.79% respectively. The bed thickness of organic-rich source rocks in the these formations are totally up to 7.88m, 74.34m, 276.60m respectively. These organic-rich rocks in the

  2. Geophysical Institute. Biennial report, 1993-1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    The 1993-1994 Geophysical Institute Biennial Report was published in November 1995 by the Geophysical Institute of the University of Alaska Fairbanks. It contains an overview of the Geophysical Institute, the Director`s Note, and research presentations concerning the following subjects: Scientific Predictions, Space Physics, Atmospheric Sciences, Snow, Ice and Permafrost, Tectonics and Sedimentation, Seismology, Volcanology, Remote Sensing, and other projects.

  3. Geophysical Imaging of Sea-level Proxies in Beach-Ridge Deposits

    Science.gov (United States)

    Nielsen, L.; Emerich Souza, P.; Meldgaard, A.; Bendixen, M.; Kroon, A.; Clemmensen, L. B.

    2017-12-01

    We show ground-penetrating radar (GPR) reflection data collected over modern and fossil beach deposits from different localities along coastlines in meso-tidal regimes of Greenland and micro-tidal regimes of Denmark. The acquired reflection GPR sections show several similar characteristics but also some differences. A similar characteristic is the presence of downlapping reflections, where the downlap point is interpreted to mark the transition from upper shoreface to beachface deposits and, thus, be a marker of a level close to or at sea-level at the time of deposition. Differences in grain size of the investigated beach ridge system result in different scattering characteristics of the acquired GPR data. These differences call for tailored, careful processing of the GPR data for optimal imaging of internal beach ridge architecture. We outline elements of the GPR data processing of particular importance for optimal imaging. Moreover, we discuss advantages and challenges related to using GPR-based proxies of sea-level as compared to other methods traditionally used for establishment of curves of past sea-level variation.

  4. Tiny Devices Project Sharp, Colorful Images

    Science.gov (United States)

    2009-01-01

    Displaytech Inc., based in Longmont, Colorado and recently acquired by Micron Technology Inc. of Boise, Idaho, first received a Small Business Innovation Research contract in 1993 from Johnson Space Center to develop tiny, electronic, color displays, called microdisplays. Displaytech has since sold over 20 million microdisplays and was ranked one of the fastest growing technology companies by Deloitte and Touche in 2005. Customers currently incorporate the microdisplays in tiny pico-projectors, which weigh only a few ounces and attach to media players, cell phones, and other devices. The projectors can convert a digital image from the typical postage stamp size into a bright, clear, four-foot projection. The company believes sales of this type of pico-projector may exceed $1.1 billion within 5 years.

  5. Geophysical Images of the Shallow Hydrothermal Degassing at Solfatara (Phlegrean Fields, Italy)

    Science.gov (United States)

    Byrdina, S.; Vandemeulebrouck, J.; Cardellini, C.; Chiodini, G.; Legaz, A.; Camerlynck, C.; Lebourg, T.

    2014-12-01

    We present the results of an electric resistivity tomography (ERT) survey, combined with mappings of diffuse carbon dioxide flux, ground temperature and self-potential (SP) at Solfatara, the most active crater of Phlegrean Fields. Solfatara is characterized by an intense carbon dioxide degassing, fumarole activity, and ground deformation. This ensemble of methods is applied to image the hydrothermal system of Solfatara, to understand the geometry of the fluid circulation, and to define the extension of the hydrothermal plume at a high enough resolution for a quantitative modeling. ERT inversion results show Solfatara as a globally conductive structure, with resistivity in the range 1-200 Ohmm. Broad negative anomaly of self-potential in the inner part of Solfatara with a minimum in the area of Bocca Grande suggests a significant downward flow of condensing liquid water. Comparison between spatial variations of resistivity and gas flux indicates that resistivity changes at depth are related to gas saturation and fluid temperature. These variations delineate two plume structures: a liquid-dominated conductive plume below Fangaia mud-pool and a gas-dominated plume below Bocca Grande fumarole. The geometry of the Fangaia liquid-saturated plume is also imaged by a high resolution 3-D resistivity model. In order to estimate the permeability, we propose a 2-D axis-symmetric numerical model coupling Richards's equation for fluid flow in conditions of partial saturation with the resistivity calculation as function of saturation only. Alternatively, we apply the Dupuit equation to estimate the permeability of the shallow layer. Using these two approaches, we obtain the permeability of the shallow layer below Fangaia which ranges between (2 - 4) 10-14 m 2.

  6. Imaging normal faults in alluvial fans using geophysical techniques: Field example from the coast of Gulf of Aqaba, Saudi Arabia

    KAUST Repository

    Hanafy, Sherif M.; Jonsson, Sigurjon; Klinger, Yann

    2014-01-01

    In this work we use geophysical methods to locate and characterize active faults in alluvial sediments. Since only subtle material and velocity contrasts are expected across the faults, we used seismic refraction tomography and 2D resistivity

  7. Time-lapse integrated geophysical imaging of magmatic injections and fluid-induced fracturing causing Campi Flegrei 1983-84 Unrest

    Science.gov (United States)

    De Siena, Luca; Crescentini, Luca; Amoruso, Antonella; Del Pezzo, Edoardo; Castellano, Mario

    2016-04-01

    Geophysical precursors measured during Unrest episodes are a primary source of geophysical information to forecast eruptions at the largest and most potentially destructive volcanic calderas. Despite their importance and uniqueness, these precursors are also considered difficult to interpret and unrepresentative of larger eruptive events. Here, we show how novel geophysical imaging and monitoring techniques are instead able to represent the dynamic evolution of magmatic- and fluid-induced fracturing during the largest period of Unrest at Campi Flegrei caldera, Italy (1983-1984). The time-dependent patterns drawn by microseismic locations and deformation, once integrated by 3D attenuation tomography and absorption/scattering mapping, model injections of magma- and fluid-related materials in the form of spatially punctual microseismic bursts at a depth of 3.5 km, west and offshore the city of Pozzuoli. The shallowest four kilometres of the crust work as a deformation-based dipolar system before and after each microseismic shock. Seismicity and deformation contemporaneously focus on the point of injection; patterns then progressively crack the medium directed towards the second focus, a region at depths 1-1.5 km south of Solfatara. A single high-absorption and high-scattering aseismic anomaly marks zones of fluid storage overlying the first dipolar centre. These results provide the first direct geophysical signature of the processes of aseismic fluid release at the top of the basaltic basement, producing pozzolanic activity and recently observed via rock-physics and well-rock experiments. The microseismicity caused by fluids and gasses rises to surface via high-absorption north-east rising paths connecting the two dipolar centres, finally beingq being generally expelled from the maar diatreme Solfatara structure. Geophysical precursors during Unrest depict how volcanic stress was released at the Campi Flegrei caldera during its period of highest recorded seismicity

  8. Nuclear Fuel Assembly Assessment Project and Image Categorization

    Energy Technology Data Exchange (ETDEWEB)

    Lindsey, C.S.; Lindblad, T.; Waldemark, K. [Royal Inst. of Tech., Stockholm (Sweden); Hildingsson, Lars [Swedish Nuclear Power Inspectorate, Stockholm (Sweden)

    1998-07-01

    A project has been underway to add digital imaging and processing to the inspection of nuclear fuel by the International Atomic Energy Agency. The ultimate goals are to provide the inspector not only with the advantages of Ccd imaging, such as high sensitivity and digital image enhancements, but also with an intelligent agent that can analyze the images and provide useful information about the fuel assemblies in real time. The project is still in the early stages and several interesting sub-projects have been inspired. Here we give first a review of the work on the fuel assembly image analysis and then give a brief status report on one of these sub-projects that concerns automatic categorization of fuel assembly images. The technique could be of benefit to the general challenge of image categorization

  9. Fast image matching algorithm based on projection characteristics

    Science.gov (United States)

    Zhou, Lijuan; Yue, Xiaobo; Zhou, Lijun

    2011-06-01

    Based on analyzing the traditional template matching algorithm, this paper identified the key factors restricting the speed of matching and put forward a brand new fast matching algorithm based on projection. Projecting the grayscale image, this algorithm converts the two-dimensional information of the image into one-dimensional one, and then matches and identifies through one-dimensional correlation, meanwhile, because of normalization has been done, when the image brightness or signal amplitude increasing in proportion, it could also perform correct matching. Experimental results show that the projection characteristics based image registration method proposed in this article could greatly improve the matching speed, which ensuring the matching accuracy as well.

  10. Determination of In-situ Rock Thermal Properties from Geophysical Log Data of SK-2 East Borehole, Continental Scientific Drilling Project of Songliao Basin, NE China

    Science.gov (United States)

    Zou, C.; Zhao, J.; Zhang, X.; Peng, C.; Zhang, S.

    2017-12-01

    Continental Scientific Drilling Project of Songliao Basin is a drilling project under the framework of ICDP. It aims at detecting Cretaceous environmental/climate changes and exploring potential resources near or beneath the base of the basin. The main hole, SK-2 East Borehole, has been drilled to penetrate through the Cretaceous formation. A variety of geophysical log data were collected from the borehole, which provide a great opportunity to analyze thermal properties of in-situ rock surrounding the borehole.The geothermal gradients were derived directly from temperature logs recorded 41 days after shut-in. The matrix and bulk thermal conductivity of rock were calculated with the geometric-mean model, in which mineral/rock contents and porosity were required as inputs (Fuchs et. al., 2014). Accurate mineral contents were available from the elemental capture spectroscopy logs and porosity data were derived from conventional logs (density, neutron and sonic). The heat production data were calculated by means of the concentrations of uranium, thorium and potassium determined from natural gamma-ray spectroscopy logs. Then, the heat flow was determined by using the values of geothermal gradients and thermal conductivity.The thermal parameters of in-situ rock over the depth interval of 0 4500m in the borehole were derived from geophysical logs. Statistically, the numerical ranges of thermal parameters are in good agreement with the measured values from both laboratory and field in this area. The results show that high geothermal gradient and heat flow exist over the whole Cretaceous formation, with anomalously high values in the Qingshankou formation (1372.0 1671.7m) and the Quantou formation (1671.7 2533.5m). It is meaningful for characterization of geothermal regime and exploration of geothermal resources in the basin. Acknowledgment: This work was supported by the "China Continental Scientific Drilling Program of Cretaceous Songliao Basin (CCSD-SK)" of China

  11. Variance in parametric images: direct estimation from parametric projections

    International Nuclear Information System (INIS)

    Maguire, R.P.; Leenders, K.L.; Spyrou, N.M.

    2000-01-01

    Recent work has shown that it is possible to apply linear kinetic models to dynamic projection data in PET in order to calculate parameter projections. These can subsequently be back-projected to form parametric images - maps of parameters of physiological interest. Critical to the application of these maps, to test for significant changes between normal and pathophysiology, is an assessment of the statistical uncertainty. In this context, parametric images also include simple integral images from, e.g., [O-15]-water used to calculate statistical parametric maps (SPMs). This paper revisits the concept of parameter projections and presents a more general formulation of the parameter projection derivation as well as a method to estimate parameter variance in projection space, showing which analysis methods (models) can be used. Using simulated pharmacokinetic image data we show that a method based on an analysis in projection space inherently calculates the mathematically rigorous pixel variance. This results in an estimation which is as accurate as either estimating variance in image space during model fitting, or estimation by comparison across sets of parametric images - as might be done between individuals in a group pharmacokinetic PET study. The method based on projections has, however, a higher computational efficiency, and is also shown to be more precise, as reflected in smooth variance distribution images when compared to the other methods. (author)

  12. Imaging Seismic Source Variations Using Back-Projection Methods at El Tatio Geyser Field, Northern Chile

    Science.gov (United States)

    Kelly, C. L.; Lawrence, J. F.

    2014-12-01

    During October 2012, 51 geophones and 6 broadband seismometers were deployed in an ~50x50m region surrounding a periodically erupting columnar geyser in the El Tatio Geyser Field, Chile. The dense array served as the seismic framework for a collaborative project to study the mechanics of complex hydrothermal systems. Contemporaneously, complementary geophysical measurements (including down-hole temperature and pressure, discharge rates, thermal imaging, water chemistry, and video) were also collected. Located on the western flanks of the Andes Mountains at an elevation of 4200m, El Tatio is the third largest geyser field in the world. Its non-pristine condition makes it an ideal location to perform minutely invasive geophysical studies. The El Jefe Geyser was chosen for its easily accessible conduit and extremely periodic eruption cycle (~120s). During approximately 2 weeks of continuous recording, we recorded ~2500 nighttime eruptions which lack cultural noise from tourism. With ample data, we aim to study how the source varies spatially and temporally during each phase of the geyser's eruption cycle. We are developing a new back-projection processing technique to improve source imaging for diffuse signals. Our method was previously applied to the Sierra Negra Volcano system, which also exhibits repeating harmonic and diffuse seismic sources. We back-project correlated seismic signals from the receivers back to their sources, assuming linear source to receiver paths and a known velocity model (obtained from ambient noise tomography). We apply polarization filters to isolate individual and concurrent geyser energy associated with P and S phases. We generate 4D, time-lapsed images of the geyser source field that illustrate how the source distribution changes through the eruption cycle. We compare images for pre-eruption, co-eruption, post-eruption and quiescent periods. We use our images to assess eruption mechanics in the system (i.e. top-down vs. bottom-up) and

  13. [Managing digital medical imaging projects in healthcare services: lessons learned].

    Science.gov (United States)

    Rojas de la Escalera, D

    2013-01-01

    Medical imaging is one of the most important diagnostic instruments in clinical practice. The technological development of digital medical imaging has enabled healthcare services to undertake large scale projects that require the participation and collaboration of many professionals of varied backgrounds and interests as well as substantial investments in infrastructures. Rather than focusing on systems for dealing with digital medical images, this article deals with the management of projects for implementing these systems, reviewing various organizational, technological, and human factors that are critical to ensure the success of these projects and to guarantee the compatibility and integration of digital medical imaging systems with other health information systems. To this end, the author relates several lessons learned from a review of the literature and the author's own experience in the technical coordination of digital medical imaging projects. Copyright © 2012 SERAM. Published by Elsevier Espana. All rights reserved.

  14. Investigating the Surface and Subsurface in Karstic Regions – Terrestrial Laser Scanning versus Low-Altitude Airborne Imaging and the Combination with Geophysical Prospecting

    Directory of Open Access Journals (Sweden)

    Nora Tilly

    2017-08-01

    Full Text Available Combining measurements of the surface and subsurface is a promising approach to understand the origin and current changes of karstic forms since subterraneous processes are often the initial driving force. A karst depression in south-west Germany was investigated in a comprehensive campaign with remote sensing and geophysical prospecting. This contribution has two objectives: firstly, comparing terrestrial laser scanning (TLS and low-altitude airborne imaging from an unmanned aerial vehicle (UAV regarding their performance in capturing the surface. Secondly, establishing a suitable way of combining this 3D surface data with data from the subsurface, derived by geophysical prospecting. Both remote sensing approaches performed satisfying and the established digital elevation models (DEMs differ only slightly. These minor discrepancies result essentially from the different viewing geometries and post-processing concepts, for example whether the vegetation was removed or not. Validation analyses against high-accurate DGPS-derived point data sets revealed slightly better results for the DEMTLS with a mean absolute difference of 0.03 m to 0.05 m and a standard deviation of 0.03 m to 0.07 m (DEMUAV: mean absolute difference: 0.11 m to 0.13 m; standard deviation: 0.09 m to 0.11 m. The 3D surface data and 2D image of the vertical cross section through the subsurface along a geophysical profile were combined in block diagrams. The data sets fit very well and give a first impression of the connection between surface and subsurface structures. Since capturing the subsurface with this method is limited to 2D and the data acquisition is quite time consuming, further investigations are necessary for reliable statements about subterraneous structures, how these may induce surface changes, and the origin of this karst depression. Moreover, geophysical prospecting can only produce a suspected image of the subsurface since the apparent resistivity is measured

  15. Photoacoustic projection imaging using an all-optical detector array

    Science.gov (United States)

    Bauer-Marschallinger, J.; Felbermayer, K.; Berer, T.

    2018-02-01

    We present a prototype for all-optical photoacoustic projection imaging. By generating projection images, photoacoustic information of large volumes can be retrieved with less effort compared to common photoacoustic computed tomography where many detectors and/or multiple measurements are required. In our approach, an array of 60 integrating line detectors is used to acquire photoacoustic waves. The line detector array consists of fiber-optic MachZehnder interferometers, distributed on a cylindrical surface. From the measured variation of the optical path lengths of the interferometers, induced by photoacoustic waves, a photoacoustic projection image can be reconstructed. The resulting images represent the projection of the three-dimensional spatial light absorbance within the imaged object onto a two-dimensional plane, perpendicular to the line detector array. The fiber-optic detectors achieve a noise-equivalent pressure of 24 Pascal at a 10 MHz bandwidth. We present the operational principle, the structure of the array, and resulting images. The system can acquire high-resolution projection images of large volumes within a short period of time. Imaging large volumes at high frame rates facilitates monitoring of dynamic processes.

  16. Scanned Image Projection System Employing Intermediate Image Plane

    Science.gov (United States)

    DeJong, Christian Dean (Inventor); Hudman, Joshua M. (Inventor)

    2014-01-01

    In imaging system, a spatial light modulator is configured to produce images by scanning a plurality light beams. A first optical element is configured to cause the plurality of light beams to converge along an optical path defined between the first optical element and the spatial light modulator. A second optical element is disposed between the spatial light modulator and a waveguide. The first optical element and the spatial light modulator are arranged such that an image plane is created between the spatial light modulator and the second optical element. The second optical element is configured to collect the diverging light from the image plane and collimate it. The second optical element then delivers the collimated light to a pupil at an input of the waveguide.

  17. Muon tomography of the Soufrière of Guadeloupe (Lesser Antilles): Comparison with other geophysical imaging methods and assessment of volcanic risks

    Science.gov (United States)

    Gibert, D.; Lesparre, N.; Marteau, J.; Taisne, B.; Nicollin, F.; Coutant, O.

    2011-12-01

    Density tomography of rock with muons of cosmic origin measures the attenuation of the flux of particles crossing the object of interest to derive its opacity, i.e. the quantity of matter encountered by the particles along their trajectories. Recent progress in micro-electronics and particle detectors make field measurement possible and muon density tomography is gaining a growing interest (e.g. Tanaka et al., 2010; Gibert et al., 2010). We have constructed field telescopes based on the detectors of the OPERA experiment devoted to study neutrino oscillation (Lesparre et al., 2011a). Each telescope may be equipped with a variable number of detection matrices with 256 pixels. The spatial resolution is adaptable and is typically of about 20 meters (Lesparre et al., 2010). The telescopes are portable autonomous devices able to operate in harsh field conditions encountered on tropical volcanoes. The total power consumption is less than 40W, and an Ethernet link allows data downloading and remote control of the electronic devices and on-board computers. Larger high-resolution telescopes are under construction. The instruments have been successfully tested on the Etna and Soufrière of Guadeloupe volcanoes were a telescope is operating continuously since Summer 2010. Muon radiographies of the Soufrière lava dome reveal its very heterogeneous density structure produced by an intense hydrothermal circulation of acid fluids which alters its mechanical integrity leading to a high risk level of destabilisation. Small-size features are visible on the images and provide precious informations on the structure of the upper hydrothermal systems. Joined interpretation with other geophysical data available on the Soufrière - seismic tomography, electrical resistivity tomography, gravity data - is presented and discussed. Density muon tomography of the internal structure of volcanoes like the Soufrière brings important informations for the hazard evaluation an is particularly

  18. Image reconstruction technique using projection data from neutron tomography system

    Directory of Open Access Journals (Sweden)

    Waleed Abd el Bar

    2015-12-01

    Full Text Available Neutron tomography is a very powerful technique for nondestructive evaluation of heavy industrial components as well as for soft hydrogenous materials enclosed in heavy metals which are usually difficult to image using X-rays. Due to the properties of the image acquisition system, the projection images are distorted by several artifacts, and these reduce the quality of the reconstruction. In order to eliminate these harmful effects the projection images should be corrected before reconstruction. This paper gives a description of a filter back projection (FBP technique, which is used for reconstruction of projected data obtained from transmission measurements by neutron tomography system We demonstrated the use of spatial Discrete Fourier Transform (DFT and the 2D Inverse DFT in the formulation of the method, and outlined the theory of reconstruction of a 2D neutron image from a sequence of 1D projections taken at different angles between 0 and π in MATLAB environment. Projections are generated by applying the Radon transform to the original image at different angles.

  19. The caBIG annotation and image Markup project.

    Science.gov (United States)

    Channin, David S; Mongkolwat, Pattanasak; Kleper, Vladimir; Sepukar, Kastubh; Rubin, Daniel L

    2010-04-01

    Image annotation and markup are at the core of medical interpretation in both the clinical and the research setting. Digital medical images are managed with the DICOM standard format. While DICOM contains a large amount of meta-data about whom, where, and how the image was acquired, DICOM says little about the content or meaning of the pixel data. An image annotation is the explanatory or descriptive information about the pixel data of an image that is generated by a human or machine observer. An image markup is the graphical symbols placed over the image to depict an annotation. While DICOM is the standard for medical image acquisition, manipulation, transmission, storage, and display, there are no standards for image annotation and markup. Many systems expect annotation to be reported verbally, while markups are stored in graphical overlays or proprietary formats. This makes it difficult to extract and compute with both of them. The goal of the Annotation and Image Markup (AIM) project is to develop a mechanism, for modeling, capturing, and serializing image annotation and markup data that can be adopted as a standard by the medical imaging community. The AIM project produces both human- and machine-readable artifacts. This paper describes the AIM information model, schemas, software libraries, and tools so as to prepare researchers and developers for their use of AIM.

  20. Total Variation and Tomographic Imaging from Projections

    DEFF Research Database (Denmark)

    Hansen, Per Christian; Jørgensen, Jakob Heide

    2011-01-01

    or 3D reconstruction from noisy projections. We demonstrate that for a small signal-to-noise ratio, this new approach allows us to compute better (i.e., more reliable) reconstructions than those obtained by classical methods. This is possible due to the use of the TV reconstruction model, which...

  1. Cross Cultural Images: The ETSU/NAU Special Photography Project.

    Science.gov (United States)

    Montgomery, Donna; Sluss, Dorothy; Lewis, Jamie; Vervelde, Peggy; Prater, Greg; Minner, Sam

    Recreation is a significant part of a full and rich life but is frequently overlooked in relation to handicapped children. A project called Cross-Cultural Images aimed to improve the quality of life for handicapped children by teaching them avocational photography skills. The project involved mildly handicapped children aged 7-11 in Appalachia, on…

  2. Dual scan CT image recovery from truncated projections

    Science.gov (United States)

    Sarkar, Shubhabrata; Wahi, Pankaj; Munshi, Prabhat

    2017-12-01

    There are computerized tomography (CT) scanners available commercially for imaging small objects and they are often categorized as mini-CT X-ray machines. One major limitation of these machines is their inability to scan large objects with good image quality because of the truncation of projection data. An algorithm is proposed in this work which enables such machines to scan large objects while maintaining the quality of the recovered image.

  3. Quantitative imaging studies with PET VI. Project II

    International Nuclear Information System (INIS)

    Copper, M.; Chen, C.T.; Yasillo, N.; Gatley, J.; Ortega, C.; DeJesus, O.; Friedman, A.

    1985-01-01

    This project is focused upon the development of hardware and software to improve PET image analysis and upon clinical applications of PET. In this report the laboratory's progress in various attenuation correction methods for brain imaging are described. The use of time-of-flight information for image reconstruction is evaluated. The location of dopamine D1 and D2 receptors in brain was found to be largely in the basal ganghia. 1 tab. (DT)

  4. Reconstruction of CT images by the Bayes- back projection method

    CERN Document Server

    Haruyama, M; Takase, M; Tobita, H

    2002-01-01

    In the course of research on quantitative assay of non-destructive measurement of radioactive waste, the have developed a unique program based on the Bayesian theory for reconstruction of transmission computed tomography (TCT) image. The reconstruction of cross-section images in the CT technology usually employs the Filtered Back Projection method. The new imaging reconstruction program reported here is based on the Bayesian Back Projection method, and it has a function of iterative improvement images by every step of measurement. Namely, this method has the capability of prompt display of a cross-section image corresponding to each angled projection data from every measurement. Hence, it is possible to observe an improved cross-section view by reflecting each projection data in almost real time. From the basic theory of Baysian Back Projection method, it can be not only applied to CT types of 1st, 2nd, and 3rd generation. This reported deals with a reconstruction program of cross-section images in the CT of ...

  5. Geophysical logging and imaging of drillholes OL-KR45, OL-KR49, OL-KR50 and OL-KR50B at Olkiluoto in 2009

    International Nuclear Information System (INIS)

    Tarvainen, A.-M.

    2010-04-01

    Suomen Malmi Oy conducted geophysical drillhole logging, acoustic imaging and optical imaging of the drillholes OL-KR45 (re-measurements), OL-KR49, OL-KR50 and OL-KR50B at the Olkiluoto site in Eurajoki during January-November 2009. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. The missing density logging of drillhole OL-KR45 was carried out successfully. Dynamic rock mechanical parameters and natural gamma data were re-processed and this report includes updated WellCAD and Excel files. Acoustic imaging was also carried out in OL-KR45 after 700 meters depth. Acoustic imaging was used instead of optical imaging after 350 meters in OL-KR49 and 700 meters in OL-KR50. (orig.)

  6. ONKALO pose experiment. Geophysical logging and imaging of drillholes ONK-PP223, ONK-PP226, ONK-PP254 and ONK-PP259...261

    International Nuclear Information System (INIS)

    Tarvainen, A.-M.

    2011-08-01

    Suomen Malmi Oy conducted geophysical drillhole logging as well as optical and acoustic imaging of shallow drillholes ONK-PP223, ONK-PP226, ONK-PP254, ONKPP259, ONK-PP260 and ONK-PP261 at ONKALO in the investigation niche ONKTKU- 3 (POSE) between December 2009 and June 2010. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  7. Geophysical drillhole logging and imaging of drillholes OL-KR54, OL-KR55 and OL-KR55B at Olkiluoto in 2010 and 2011

    International Nuclear Information System (INIS)

    Tarvainen, A.-M.; Heikkinen, E.

    2011-08-01

    Suomen Malmi Oy conducted geophysical drillhole logging as well as optical and acoustic imaging of the drillholes OL-KR54, OL-KR55 and OL-KR55B at the Olkiluoto site in Eurajoki between August 2010 and January 2011. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. New focused resistivity, susceptibility, natural gamma and density probes were tested and compared with old probes. This report describes the major features of new probes and the comparison with old probes. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  8. The Van Sant AVHRR image projected onto a rhombicosidodecahedron

    Science.gov (United States)

    Baron, Michael; Morain, Stan

    1996-03-01

    IDEATION, a design and development corporation, Santa Fe, New Mexico, has modeled Tom Van Sant's ``The Earth From Space'' image to a rhombicosidodecahedron. ``The Earth from Space'' image, produced by the Geosphere® Project in Santa Monica, California, was developed from hundreds of AVHRR pictures and published as a Mercator projection. IDEATION, utilizing a digitized Robinson Projection, fitted the image to foldable, paper components which, when interconnected by means of a unique tabular system, results in a rhombicosidodecahedron representation of the Earth exposing 30 square, 20 triangular, and 12 pentagonal faces. Because the resulting model is not spherical, the borders of the represented features were rectified to match the intersecting planes of the model's faces. The resulting product will be licensed and commercially produced for use by elementary and secondary students. Market research indicates the model will be used in both the demonstration of geometric principles and the teaching of fundamental spatial relations of the Earth's lands and oceans.

  9. Sustainable urban development and geophysics

    Science.gov (United States)

    Liu, Lanbo; Chan, L. S.

    2007-09-01

    The new millennium has seen a fresh wave of world economic development especially in the Asian-Pacific region. This has contributed to further rapid urban expansion, creating shortages of energy and resources, degradation of the environment, and changes to climatic patterns. Large-scale, new urbanization is mostly seen in developing countries but urban sprawl is also a major social problem for developed nations. Urbanization has been accelerating at a tremendous rate. According to data collected by the United Nations [1], 50 years ago less than 30% of the world population lived in cities. Now, more than 50% are living in urban settings which occupy only about 1% of the Earth's surface. During the period from 1950 to 1995, the number of cities with a population higher than one million increased from 83 to 325. By 2025 it is estimated that more than 60% of 8.3 billion people (the projected world population [1]) will be city dwellers. Urbanization and urban sprawl can affect our living quality both positively and negatively. In recent years geophysics has found significant and new applications in highly urbanized settings. Such applications are conducive to the understanding of the changes and impacts on the physical environment and play a role in developing sustainable urban infrastructure systems. We would like to refer to this field of study as 'urban geophysics'. Urban geophysics is not simply the application of geophysical exploration in the cities. Urbanization has brought about major changes to the geophysical fields of cities, including those associated with electricity, magnetism, electromagnetism and heat. An example is the increased use of electromagnetic waves in wireless communication, transportation, office automation, and computer equipment. How such an increased intensity of electromagnetic radiation affects the behaviour of charged particles in the atmosphere, the equilibrium of ecological systems, or human health, are new research frontiers to be

  10. Projection Operators and Moment Invariants to Image Blurring

    Czech Academy of Sciences Publication Activity Database

    Flusser, Jan; Suk, Tomáš; Boldyš, Jiří; Zitová, Barbara

    2015-01-01

    Roč. 37, č. 4 (2015), s. 786-802 ISSN 0162-8828 R&D Projects: GA ČR GA13-29225S; GA ČR GAP103/11/1552 Institutional support: RVO:67985556 Keywords : Blurred image * N-fold rotation symmetry * projection operators * image moments * moment invariants * blur invariants * object recognition Subject RIV: JD - Computer Applications, Robotics Impact factor: 6.077, year: 2015 http://library.utia.cas.cz/separaty/2014/ZOI/flusser-0434521.pdf

  11. SAT-MAP-CLIMATE project results[SATellite base bio-geophysical parameter MAPping and aggregation modelling for CLIMATE models

    Energy Technology Data Exchange (ETDEWEB)

    Bay Hasager, C.; Woetmann Nielsen, N.; Soegaard, H.; Boegh, E.; Hesselbjerg Christensen, J.; Jensen, N.O.; Schultz Rasmussen, M.; Astrup, P.; Dellwik, E.

    2002-08-01

    Earth Observation (EO) data from imaging satellites are analysed with respect to albedo, land and sea surface temperatures, land cover types and vegetation parameters such as the Normalized Difference Vegetation Index (NDVI) and the leaf area index (LAI). The observed parameters are used in the DMI-HIRLAM-D05 weather prediction model in order to improve the forecasting. The effect of introducing actual sea surface temperatures from NOAA AVHHR compared to climatological mean values, shows a more pronounced land-sea breeze effect which is also observable in field observations. The albedo maps from NOAA AVHRR are rather similar to the climatological mean values so for the HIRLAM model this is insignicant, yet most likely of some importance in the HIRHAM regional climate model. Land cover type maps are assigned local roughness values determined from meteorological field observations. Only maps with a spatial resolution around 25 m can adequately map the roughness variations of the typical patch size distribution in Denmark. A roughness map covering Denmark is aggregated (ie area-average non-linearly) by a microscale aggregation model that takes the non-linear turbulent responses of each roughness step change between patches in an arbitrary pattern into account. The effective roughnesses are calculated into a 15 km by 15 km grid for the HIRLAM model. The effect of hedgerows is included as an added roughness effect as a function of hedge density mapped from a digital vector map. Introducing the new effective roughness maps into the HIRLAM model appears to remedy on the seasonal wind speed bias over land and sea in spring. A new parameterisation on the effective roughness for scalar surface fluxes is developed and tested on synthetic data. Further is a method for the estimation the evapotranspiration from albedo, surface temperatures and NDVI succesfully compared to field observations. The HIRLAM predictions of water vapour at 12 GMT are used for atmospheric correction of

  12. Integrating Electromagnetic Data with Other Geophysical Observations for Enhanced Imaging of the Earth: A Tutorial and Review

    Science.gov (United States)

    Moorkamp, Max

    2017-09-01

    In this review, I discuss the basic principles of joint inversion and constrained inversion approaches and show a few instructive examples of applications of these approaches in the literature. Starting with some basic definitions of the terms joint inversion and constrained inversion, I use a simple three-layered model as a tutorial example that demonstrates the general properties of joint inversion with different coupling methods. In particular, I investigate to which extent combining different geophysical methods can restrict the set of acceptable models and under which circumstances the results can be biased. Some ideas on how to identify such biased results and how negative results can be interpreted conclude the tutorial part. The case studies in the second part have been selected to highlight specific issues such as choosing an appropriate parameter relationship to couple seismic and electromagnetic data and demonstrate the most commonly used approaches, e.g., the cross-gradient constraint and direct parameter coupling. Throughout the discussion, I try to identify topics for future work. Overall, it appears that integrating electromagnetic data with other observations has reached a level of maturity and is starting to move away from fundamental proof-of-concept studies to answering questions about the structure of the subsurface. With a wide selection of coupling methods suited to different geological scenarios, integrated approaches can be applied on all scales and have the potential to deliver new answers to important geological questions.

  13. Imaging and locating paleo-channels using geophysical data from meandering system of the Mun River, Khorat Plateau, Northeastern Thailand

    Science.gov (United States)

    Nimnate, P.; Thitimakorn, T.; Choowong, M.; Hisada, K.

    2017-12-01

    The Khorat Plateau from northeast Thailand, the upstream part of the Mun River flows through clastic sedimentary rocks. A massive amount of sand was transported. We aimed to understand the evolution of fluvial system and to discuss the advantages of two shallow geophysical methods for describing subsurface morphology of modern and paleo-channels. We applied Electrical Resistivity Tomography (ERT) and Ground Penetrating Radar (GPR) to characterize the lateral, vertical morphological and sedimentary structures of paleo-channels, floodplain and recent point bars. Both methods were interpreted together with on-sites boreholes to describe the physical properties of subsurface sediments. As a result, we concluded that four radar reflection patterns including reflection free, shingled, inclined and hummocky reflections were appropriated to apply as criteria to characterize lateral accretion, the meandering rivers with channel-filled sequence and floodplain were detected from ERT profiles. The changes in resistivity correspond well with differences in particle size and show relationship with ERT lithological classes. Clay, silt, sand, loam and bedrock were classified by the resistivity data. Geometry of paleo-channel embayment and lithological differences can be detected by ERT, whereas GPR provides detail subsurface facies for describing point bar sand deposit better than ERT.

  14. Imaging and locating paleo-channels using geophysical data from meandering system of the Mun River, Khorat Plateau, Northeastern Thailand

    Directory of Open Access Journals (Sweden)

    Nimnate P.

    2017-12-01

    Full Text Available The Khorat Plateau from northeast Thailand, the upstream part of the Mun River flows through clastic sedimentary rocks. A massive amount of sand was transported. We aimed to understand the evolution of fluvial system and to discuss the advantages of two shallow geophysical methods for describing subsurface morphology of modern and paleo-channels. We applied Electrical Resistivity Tomography (ERT and Ground Penetrating Radar (GPR to characterize the lateral, vertical morphological and sedimentary structures of paleo-channels, floodplain and recent point bars. Both methods were interpreted together with on-sites boreholes to describe the physical properties of subsurface sediments. As a result, we concluded that four radar reflection patterns including reflection free, shingled, inclined and hummocky reflections were appropriated to apply as criteria to characterize lateral accretion, the meandering rivers with channel-filled sequence and floodplain were detected from ERT profiles. The changes in resistivity correspond well with differences in particle size and show relationship with ERT lithological classes. Clay, silt, sand, loam and bedrock were classified by the resistivity data. Geometry of paleo-channel embayment and lithological differences can be detected by ERT, whereas GPR provides detail subsurface facies for describing point bar sand deposit better than ERT.

  15. Discriminating Projections for Estimating Face Age in Wild Images

    Energy Technology Data Exchange (ETDEWEB)

    Tokola, Ryan A [ORNL; Bolme, David S [ORNL; Ricanek, Karl [ORNL; Barstow, Del R [ORNL; Boehnen, Chris Bensing [ORNL

    2014-01-01

    We introduce a novel approach to estimating the age of a human from a single uncontrolled image. Current face age estimation algorithms work well in highly controlled images, and some are robust to changes in illumination, but it is usually assumed that images are close to frontal. This bias is clearly seen in the datasets that are commonly used to evaluate age estimation, which either entirely or mostly consist of frontal images. Using pose-specific projections, our algorithm maps image features into a pose-insensitive latent space that is discriminative with respect to age. Age estimation is then performed using a multi-class SVM. We show that our approach outperforms other published results on the Images of Groups dataset, which is the only age-related dataset with a non-trivial number of off-axis face images, and that we are competitive with recent age estimation algorithms on the mostly-frontal FG-NET dataset. We also experimentally demonstrate that our feature projections introduce insensitivity to pose.

  16. Integrated variable projection approach (IVAPA) for parallel magnetic resonance imaging.

    Science.gov (United States)

    Zhang, Qiao; Sheng, Jinhua

    2012-10-01

    Parallel magnetic resonance imaging (pMRI) is a fast method which requires algorithms for the reconstructing image from a small number of measured k-space lines. The accurate estimation of the coil sensitivity functions is still a challenging problem in parallel imaging. The joint estimation of the coil sensitivity functions and the desired image has recently been proposed to improve the situation by iteratively optimizing both the coil sensitivity functions and the image reconstruction. It regards both the coil sensitivities and the desired images as unknowns to be solved for jointly. In this paper, we propose an integrated variable projection approach (IVAPA) for pMRI, which integrates two individual processing steps (coil sensitivity estimation and image reconstruction) into a single processing step to improve the accuracy of the coil sensitivity estimation using the variable projection approach. The method is demonstrated to be able to give an optimal solution with considerably reduced artifacts for high reduction factors and a low number of auto-calibration signal (ACS) lines, and our implementation has a fast convergence rate. The performance of the proposed method is evaluated using a set of in vivo experiment data. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Object-Image Correspondence for Algebraic Curves under Projections

    Directory of Open Access Journals (Sweden)

    Joseph M. Burdis

    2013-03-01

    Full Text Available We present a novel algorithm for deciding whether a given planar curve is an image of a given spatial curve, obtained by a central or a parallel projection with unknown parameters. The motivation comes from the problem of establishing a correspondence between an object and an image, taken by a camera with unknown position and parameters. A straightforward approach to this problem consists of setting up a system of conditions on the projection parameters and then checking whether or not this system has a solution. The computational advantage of the algorithm presented here, in comparison to algorithms based on the straightforward approach, lies in a significant reduction of a number of real parameters that need to be eliminated in order to establish existence or non-existence of a projection that maps a given spatial curve to a given planar curve. Our algorithm is based on projection criteria that reduce the projection problem to a certain modification of the equivalence problem of planar curves under affine and projective transformations. To solve the latter problem we make an algebraic adaptation of signature construction that has been used to solve the equivalence problems for smooth curves. We introduce a notion of a classifying set of rational differential invariants and produce explicit formulas for such invariants for the actions of the projective and the affine groups on the plane.

  18. Rapid geophysical surveyor

    International Nuclear Information System (INIS)

    Roybal, L.G.; Carpenter, G.S.; Josten, N.E.

    1993-01-01

    The Rapid Geophysical Surveyor (RGS) is a system designed to rapidly and economically collect closely-spaced geophysical data used for characterization of Department of Energy (DOE) waste sites. Geophysical surveys of waste sites are an important first step in the remediation and closure of these sites; especially older sties where historical records are inaccurate and survey benchmarks have changed due to refinements in coordinate controls and datum changes. Closely-spaced data are required to adequately differentiate pits, trenches, and soil vault rows whose edges may be only a few feet from each other. A prototype vehicle designed to collect magnetic field data was built at the Idaho national Engineering Laboratory (INEL) during the summer of 1992. The RGS was one of several projects funded by the Buried Waste Integrated Demonstration (BWID) program. This vehicle was demonstrated at the Subsurface Disposal Area (SDA) within the Radioactive Waste Management Complex (RWMC) on the INEL in September of 1992. Magnetic data were collected over two areas in the SDA, with a total survey area of about 1.7 acres. Data were collected at a nominal density of 2 1/2 inches along survey lines spaced 1 foot apart. Over 350,000 data points were collected over a 6 day period corresponding to about 185 man-days using conventional ground survey techniques. This report documents the design and demonstration of the RGS concept including the presentation of magnetic data collected at the SDA. The surveys were able to show pit and trench boundaries and determine details of their spatial orientation never before achieved

  19. The Expanding Marketplace for Applied Geophysics

    Science.gov (United States)

    Carlson, N.; Sirles, P.

    2012-12-01

    While the image of geophysics for the proverbial "layman" often seems limited to volcanoes and earthquakes, and to the geoscientist this image enlarges to include oil or minerals exploration and whole earth studies, there has been a steady increase in the application of geophysics into the realm of "daily life", such as real estate deals, highway infrastructure, and flood protection. This expansion of applications can be attributed to the improved economics from advances in equipment and interpretation. Traditional geophysical methods that at one time often only fit within the budgets of oil, gas, and minerals exploration programs can now be economically applied to much smaller scale needs like contaminant mapping, landfill delineation, and levee investigations. A real-world, economic example of this expanding marketplace is our company, which began very small and was aimed almost exclusively at the minerals exploration market. Most of our growth has been in the last 10 years, when we have expanded to five offices and a staff with almost 40 geoscientist degrees (21 in geophysics); much of this growth has been in the non-oil, non-minerals arenas. While much of our work still includes minerals exploration, other projects this year include wind-farm foundation studies, cavity detection above underground nuclear tests, landfill studies, acid mine drainage problems, and leaks in evaporation ponds. A methodology example of this expanding market is the induced polarization (IP) survey, once primarily used for minerals exploration, particularly large porphyry copper deposits, but now efficient enough to also use in environmental studies. The IP method has been particularly useful in delineating and characterizing old, poorly documented landfills, and recent research suggests it may also be useful in monitoring the accelerated biodegradation processes used in some cases to rehabilitate the sites. Compared to temperature monitoring systems, IP may be more useful in providing

  20. Color image quality in projection displays: a case study

    Science.gov (United States)

    Strand, Monica; Hardeberg, Jon Y.; Nussbaum, Peter

    2005-01-01

    Recently the use of projection displays has increased dramatically in different applications such as digital cinema, home theatre, and business and educational presentations. Even if the color image quality of these devices has improved significantly over the years, it is still a common situation for users of projection displays that the projected colors differ significantly from the intended ones. This study presented in this paper attempts to analyze the color image quality of a large set of projection display devices, particularly investigating the variations in color reproduction. As a case study, a set of 14 projectors (LCD and DLP technology) at Gjovik University College have been tested under four different conditions: dark and light room, with and without using an ICC-profile. To find out more about the importance of the illumination conditions in a room, and the degree of improvement when using an ICC-profile, the results from the measurements was processed and analyzed. Eye-One Beamer from GretagMacbeth was used to make the profiles. The color image quality was evaluated both visually and by color difference calculations. The results from the analysis indicated large visual and colorimetric differences between the projectors. Our DLP projectors have generally smaller color gamut than LCD projectors. The color gamuts of older projectors are significantly smaller than that of newer ones. The amount of ambient light reaching the screen is of great importance for the visual impression. If too much reflections and other ambient light reaches the screen, the projected image gets pale and has low contrast. When using a profile, the differences in colors between the projectors gets smaller and the colors appears more correct. For one device, the average ΔE*ab color difference when compared to a relative white reference was reduced from 22 to 11, for another from 13 to 6. Blue colors have the largest variations among the projection displays and makes them

  1. Joint inversion of geophysical data for site characterization and restoration monitoring. 1998 annual progress report

    International Nuclear Information System (INIS)

    Berge, P.A.; Berryman, J.G.; Roberts, J.J.; Wildenschild, D.

    1998-01-01

    'The purpose of this project is to develop a computer code for joint inversion of seismic and electrical data, to improve underground imaging for site characterization and remediation monitoring. The computer code developed in this project will invert geophysical data to obtain direct estimates of porosity and saturation underground, rather than inverting for seismic velocity and electrical resistivity or other geophysical properties. This is intended to be a significant improvement in the state-of-the-art of underground imaging, since interpretation of data collected at a contaminated site would become much less subjective. Potential users include DOE scientists and engineers responsible for characterizing contaminated sites and monitoring remediation of contaminated sites. In this three-year project, the authors use a multi-phase approach consisting of theoretical and numerical code development, laboratory investigations, testing on available laboratory and borehole geophysics data sets, and a controlled field experiment, to develop practical tools for joint electrical and seismic data interpretation. This report summarizes work after about 1.7 years of a 3-year project. Progress on laboratory measurements is described first, followed by progress on developing algorithms for the inversion code to relate geophysical data to porosity and saturation.'

  2. A study of images of Projective Angles of pulmonary veins

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jue [Beijing Anzhen Hospital, Beijing (China); Zhaoqi, Zhang [Beijing Anzhen Hospital, Beijing (China)], E-mail: zhaoqi5000@vip.sohu.com; Yu Wei; Miao Cuilian; Yan Zixu; Zhao Yike [Beijing Anzhen Hospital, Beijing (China)

    2009-09-15

    Aims: In images of magnetic resonance and computed tomography (CT) there are visible angles between pulmonary veins and the coronary, transversal or sagittal section of body. In this study these angles are measured and defined as Projective Angles of pulmonary veins. Several possible influential factors and characters of distribution are studied and analyzed for a better understanding of this imaging anatomic character of pulmonary veins. And it could be the anatomic base of adjusting correctly the angle of the central X-ray of the angiography of pulmonary veins undergoing the catheter ablation of atrial fibrillation (AF). Method: Images of contrast enhanced magnetic resonance angiography (CEMRA) and contrast enhanced computer tomography (CECT) of the left atrium and pulmonary veins of 137 health objects and patients with atrial fibrillation (AF) are processed with the technique of post-processing, and Projective Angles to the coronary and transversal sections are measured and analyzed statistically. Result: Project Angles of pulmonary veins are one of real and steady imaging anatomic characteristics of pulmonary veins. The statistical distribution of variables is relatively concentrated, with a fairly good representation of average value. It is possible to improve the angle of the central X-ray according to the average value in the selective angiography of pulmonary veins undergoing the catheter ablation of AF.

  3. Parametric image reconstruction using spectral analysis of PET projection data

    International Nuclear Information System (INIS)

    Meikle, Steven R.; Matthews, Julian C.; Cunningham, Vincent J.; Bailey, Dale L.; Livieratos, Lefteris; Jones, Terry; Price, Pat

    1998-01-01

    Spectral analysis is a general modelling approach that enables calculation of parametric images from reconstructed tracer kinetic data independent of an assumed compartmental structure. We investigated the validity of applying spectral analysis directly to projection data motivated by the advantages that: (i) the number of reconstructions is reduced by an order of magnitude and (ii) iterative reconstruction becomes practical which may improve signal-to-noise ratio (SNR). A dynamic software phantom with typical 2-[ 11 C]thymidine kinetics was used to compare projection-based and image-based methods and to assess bias-variance trade-offs using iterative expectation maximization (EM) reconstruction. We found that the two approaches are not exactly equivalent due to properties of the non-negative least-squares algorithm. However, the differences are small ( 1 and, to a lesser extent, VD). The optimal number of EM iterations was 15-30 with up to a two-fold improvement in SNR over filtered back projection. We conclude that projection-based spectral analysis with EM reconstruction yields accurate parametric images with high SNR and has potential application to a wide range of positron emission tomography ligands. (author)

  4. Comparison of power spectra for tomosynthesis projections and reconstructed images

    International Nuclear Information System (INIS)

    Engstrom, Emma; Reiser, Ingrid; Nishikawa, Robert

    2009-01-01

    Burgess et al. [Med. Phys. 28, 419-437 (2001)] showed that the power spectrum of mammographic breast background follows a power law and that lesion detectability is affected by the power-law exponent β which measures the amount of structure in the background. Following the study of Burgess et al., the authors measured and compared the power-law exponent of mammographic backgrounds in tomosynthesis projections and reconstructed slices to investigate the effect of tomosynthesis imaging on background structure. Our data set consisted of 55 patient cases. For each case, regions of interest (ROIs) were extracted from both projection images and reconstructed slices. The periodogram of each ROI was computed by taking the squared modulus of the Fourier transform of the ROI. The power-law exponent was determined for each periodogram and averaged across all ROIs extracted from all projections or reconstructed slices for each patient data set. For the projections, the mean β averaged across the 55 cases was 3.06 (standard deviation of 0.21), while it was 2.87 (0.24) for the corresponding reconstructions. The difference in β for a given patient between the projection ROIs and the reconstructed ROIs averaged across the 55 cases was 0.194, which was statistically significant (p<0.001). The 95% CI for the difference between the mean value of β for the projections and reconstructions was [0.170, 0.218]. The results are consistent with the observation that the amount of breast structure in the tomosynthesis slice is reduced compared to projection mammography and that this may lead to improved lesion detectability.

  5. Measuring Brand Image Effects of Flagship Projects for Place Brands

    DEFF Research Database (Denmark)

    Zenker, Sebastian; Beckmann, Suzanne C.

    2013-01-01

    Cities invest large sums of money in ‘flagship projects’, with the aim of not only developing the city as such, but also changing the perceptions of the city brand towards a desired image. The city of Hamburg, Germany, is currently investing euro575 million in order to build a new symphony hall...... (Elbphilharmonie), euro400 million to develop the ‘International Architectural Fair’ and it is also considering candidature again for the ‘Olympic Games’ in 2024/2028. As assessing the image effects of such projects is rather difficult, this article introduces an improved version of the Brand Concept Map approach......, which was originally developed for product brands. An experimental design was used to first measure the Hamburg brand as such and then the changes in the brand perceptions after priming the participants (N=209) for one of the three different flagship projects. The findings reveal several important...

  6. Projection model for flame chemiluminescence tomography based on lens imaging

    Science.gov (United States)

    Wan, Minggang; Zhuang, Jihui

    2018-04-01

    For flame chemiluminescence tomography (FCT) based on lens imaging, the projection model is essential because it formulates the mathematical relation between the flame projections captured by cameras and the chemiluminescence field, and, through this relation, the field is reconstructed. This work proposed the blurry-spot (BS) model, which takes more universal assumptions and has higher accuracy than the widely applied line-of-sight model. By combining the geometrical camera model and the thin-lens equation, the BS model takes into account perspective effect of the camera lens; by combining ray-tracing technique and Monte Carlo simulation, it also considers inhomogeneous distribution of captured radiance on the image plane. Performance of these two models in FCT was numerically compared, and results showed that using the BS model could lead to better reconstruction quality in wider application ranges.

  7. Geophysical imaging of the lacustrine sediments deposited in the La Calderilla Volcanic Caldera (Gran Canaria Island, Spain) for paleoclimate research

    Science.gov (United States)

    Himi, Mahjoub; Rodríguez-González, Alejandro; Criado, Constantino; Tapias, Josefina C.; Ravazzi, Cesare; Pérez-Torrado, Francisco; Casas, Albert

    2016-04-01

    The discovery of well-preserved maar structures is important not only for studying the eruptive activity and formation of volcanoes, but also for paleoclimate research, since laminated maar lake sediments may contain very detailed archives of climate and environmental history. Maars are a singular type of volcanic structure generated by explosive phreatomagmatic eruptions as a result of interaction between rising magma and groundwater. This kind of structures are characterised by circular craters, often filled with water and/or lacustrine sediments and surrounded by a ring of pyroclastic deposits.Recently a borehole was drilled at the bottom of La Calderilla volcanic complex which penetrated about 8.7 m in its sedimentary sequence and paleobotanical study has supplied the first evidence of paleoenvironmental evolution during the Holocene on the Gran Canaria Island. This survey, however, did not penetrate into the substrate because the total thickness of the sedimentary fill was unknown. Since the age of formation of La Calderilla volcanic complex based on K/Ar dating is about 85,000 years (Upper Pleistocene), the possibility of its sedimentary fill extends beyond of the Holocene is extremely attractive, since, for example, there are few paleoenvironmental data regarding how much the last glaciation that affected the Canary Islands. In these circumstances, the knowledge of the total thickness of the lacustrine sediments is crucial to design a deeper borehole in the next future. Therefore, the subsurface characterisation provided by geophysics is essential for determining thickness and geometry of the sedimentary filling. Multielectrode ERT method was used to obtain five 2-D resistivity cross-sections into La Calderilla volcanic caldera. An Iris Syscal Pro resistivity system with 48 electrodes connected to a 94 m long cable (2m electrode spacing) in Wenner-Schlumberger configuration for an investigation depth of about 20 m. Data quality (q Current injected was

  8. Geophysical investigation and characterization with USRADS

    International Nuclear Information System (INIS)

    Flynn, C.R.; Blair, M.S.; Nyquist, J.E.

    1992-01-01

    This paper describes two recent case histories in which commercially available geophysical instruments were used with an innovative tracking and mapping system called USRADS (UltraSonic Ranging And Data System) that automates data location and collection. USRADS uses ultrasonics to provide real-time surveyor positioning and radio links to transmit the surveyor data to an on-site computer for storage and real-time display. USRADS uses a standard 386 computer for data collection and includes real-time color display of the findings. It also includes numerous analysis and display formats for on-site, as well as utilities to facilitate post-process analysis of the findings. The objective of one project was to locate several suspect waste disposal trenches and to map their boundaries. The second was to locate and map the presence of subsurface unexploded ordinance (UXO) at a suspect artillery impact area. A Geonics EM31 terrain conductivity meter interfaced to USRADS was used to map the suspect trenches. A Schonstedt GA-52C magnetometer interfaced to USRADS was used to map the subsurface UXO. Correlation of findings to known site features and additional knowledge about the sites indicates that these efforts did locate and map the geophysical features including the suspect waste trenches and the subsurface UXO. Images of the findings generated on-site and during post-processing are included

  9. Geophysical Investigation using Two Dimensional Electrical Resistivity Tomography method to delineate Subsurface Geological Structures at Dudhkoshi-II (230 MW) Hydroelectric Project, Solukhumbu District, Eastern Nepal

    Science.gov (United States)

    Ghimire, H.; Bhusal, U. C.; Khatiwada, B.; Pandey, D.

    2017-12-01

    Geophysical investigation using two dimensional electrical resistivity tomography (2D-ERT) method plays a significant role in determining the subsurface resistivity distribution by making measurement on the ground surface. This method was carried out at Dudhkoshi-II (230 MW) Hydroelectric Project, lies on Lesser Himalayan region of the Eastern Nepal to delineate the nature of the subsurface geology to assess its suitability for the construction of dam, desanding basin and powerhouse. The main objective of the proposed study consists of mapping vertical as well as horizontal variations of electrical resistivity to enable detection of the boundaries between unconsolidated materials and rocks of the different resistivity, possible geologic structures, such as possible presence of faults, fractures, and voids in intake and powerhouse area. For this purpose, the (WDJD-4 Multi-function Digital DC Resistivity/IP) equipment was used with Wenner array (60 electrodes). To fulfill these objectives of the study, the site area was mapped by Nine ERT profiles with different profile length and space between electrodes was 5 m. The depth of the investigation was 50 m. The acquired data were inverted to tomogram sections using tomographic inversion with RES2DINV commercial software. The Tomography sections show that the subsurface is classified into distinct geo-electric layers of dry unconsolidated overburden, saturated overburden, fractured rock and fresh bedrock of phyllites with quartzite and gneiss with different resistivity values. There were no voids and faults in the study area. Thickness of overburden at different region found to be different. Most of the survey area has bedrock of phyllites with quartzite; gneiss is also present in some location at intake area. Bedrock is found at the varies depth of 5-8 m at dam axis, 20-32 m at desanding basin and 3-10 m at powerhouse area. These results are confirmed and verified by using several boreholes data were drilled on the

  10. Serious games for Geophysics

    Science.gov (United States)

    Lombardo, Valerio; Rubbia, Giuliana

    2015-04-01

    Childhood stage is indispensable in the education of human beings and especially critical to arise scientific interest in children. We discuss the participatory design of a didactic videogame, i.e. a "serious" game to teach geophysics and Earth sciences to high and low-school students. Geophysics is the application of the laws and techniques of physics to uncover knowledge about the earth's dynamic processes and subsurface structure. It explores phenomena such as earthquakes, volcanoes, tsunamis to improve our understanding of the earth's physical processes and our ability to predict reoccurrences. Effective mitigation of risks from catastrophic geologic hazards requires knowledge and understanding of local geology and geologic processes. Scientific outreach can be defined as discourse activity, whose main objective is to communicate some knowledge previously produced in scientific contexts to a non-expert massive audience. One of the difficulties science educators need to overcome is to explain specific concepts from a given discipline in a language simple and understandable for their audience. Digital games today play a large role in young people's lives. Games are directly connected to the life of today's adolescents. Therefore, digital games should be included and broached as a subject in the classroom. The ardor and enthusiasm that digital games evoke in teenagers has indeed brought many researchers, school leaders and teachers to the question "how video games" can be used to engage young people and support their learning inside the classroom. Additionally, studies have shown that digital games can enhance various skills such as the ability to concentrate, stamina, tactical aptness, anticipatory thinking, orientation in virtual spaces, and deductive reasoning. Thus, videogames become an effective didactic mechanism and should have a place in the classroom. The project aims to explore the potentials of entertainment technologies in educational processes

  11. Advances in geophysics

    CERN Document Server

    Sato, Haruo

    2013-01-01

    The critically acclaimed serialized review journal for over 50 years, Advances in Geophysics is a highly respected publication in the field of geophysics. Since 1952, each volume has been eagerly awaited, frequently consulted, and praised by researchers and reviewers alike. Now in its 54th volume, it contains much material still relevant today--truly an essential publication for researchers in all fields of geophysics.Key features: * Contributions from leading authorities * Informs and updates on all the latest developments in the field

  12. Qualitative and quantitative analysis of reconstructed images using projections with noises

    International Nuclear Information System (INIS)

    Lopes, R.T.; Assis, J.T. de

    1988-01-01

    The reconstruction of a two-dimencional image from one-dimensional projections in an analytic algorithm ''convolution method'' is simulated on a microcomputer. In this work it was analysed the effects caused in the reconstructed image in function of the number of projections and noise level added to the projection data. Qualitative and quantitative (distortion and image noise) comparison were done with the original image and the reconstructed images. (author) [pt

  13. COTHERM: Geophysical Modeling of High Enthalpy Geothermal Systems

    Science.gov (United States)

    Grab, Melchior; Maurer, Hansruedi; Greenhalgh, Stewart

    2014-05-01

    In recent years geothermal heating and electricity generation have become an attractive alternative energy resource, especially natural high enthalpy geothermal systems such as in Iceland. However, the financial risk of installing and operating geothermal power plants is still high and more needs to be known about the geothermal processes and state of the reservoir in the subsurface. A powerful tool for probing the underground system structure is provided by geophysical techniques, which are able to detect flow paths and fracture systems without drilling. It has been amply demonstrated that small-scale features can be well imaged at shallow depths, but only gross structures can be delineated for depths of several kilometers, where most high enthalpy systems are located. Therefore a major goal of our study is to improve geophysical mapping strategies by multi-method geophysical simulations and synthetic data inversions, to better resolve structures at greater depth, characterize the reservoir and monitor any changes within it. The investigation forms part of project COTHERM - COmbined hydrological, geochemical and geophysical modeling of geoTHERMal systems - in which a holistic and synergistic approach is being adopted to achieve multidisciplinary cooperation and mutual benefit. The geophysical simulations are being performed in combination with hydrothermal fluid flow modeling and chemical fluid rock interaction modeling, to provide realistic constraints on lithology, pressure, temperature and fluid conditions of the subsurface. Two sites in Iceland have been selected for the study, Krafla and Reykjanes. As a starting point for the geophysical modeling, we seek to establish petrophysical relations, connecting rock properties and reservoir conditions with geophysical parameters such as seismic wave speed, attenuation, electrical conductivity and magnetic susceptibility with a main focus on seismic properties. Therefore, we follow a comprehensive approach involving

  14. Applications of geomorphology, tectonics, geology and geophysical interpretation of, East Kom Ombo depression, Egypt, using Landsat images

    Directory of Open Access Journals (Sweden)

    El Sayed A. El Gammal

    2013-12-01

    Full Text Available In the Southern Eastern Desert of Egypt, A NW–SE oriented structural graben extends from the North of Aswan to the Red Sea coast with a length of about 400 km and an average width of 30 km. The area has significant potential for development as it may be provided with water from surface and subsurface sources and is the site of prospection for petroleum. The present paper is an attempt to understand the structural evolution and genetic development of the geomorphologic features of the area and constructing presently a new geomorphological map at a scale of 1:250,000 using Landsat ETM images and field checks. Available geological maps and the produced geomorphological map are digitized by using the ARC-GIS software. The same program is also used to produce a 3D DEM for surface and subsurface features. Based on new interpretations of aeromagnetic and radiometric data, the subsurface features of the basement cover were illustrated on a 3D map. Geological–geomorphological profiles have been constructed in different directions in the area to identify present and ancient geomorphologic features. The place and shape of subsurface deep seated NW–SE trending faults have been determined. The faults, which generated the graben have downthrows in the order of 900–5800 m. The surface and subsurface observations delineate the dominant downthrow of about 3750 m. Three E–W subsurface faults have been detected under Nubia sandstone, one of them, displaying a downthrow of about 845 m, cuts through the basement rocks.

  15. Sparse Nonlinear Electromagnetic Imaging Accelerated With Projected Steepest Descent Algorithm

    KAUST Repository

    Desmal, Abdulla

    2017-04-03

    An efficient electromagnetic inversion scheme for imaging sparse 3-D domains is proposed. The scheme achieves its efficiency and accuracy by integrating two concepts. First, the nonlinear optimization problem is constrained using L₀ or L₁-norm of the solution as the penalty term to alleviate the ill-posedness of the inverse problem. The resulting Tikhonov minimization problem is solved using nonlinear Landweber iterations (NLW). Second, the efficiency of the NLW is significantly increased using a steepest descent algorithm. The algorithm uses a projection operator to enforce the sparsity constraint by thresholding the solution at every iteration. Thresholding level and iteration step are selected carefully to increase the efficiency without sacrificing the convergence of the algorithm. Numerical results demonstrate the efficiency and accuracy of the proposed imaging scheme in reconstructing sparse 3-D dielectric profiles.

  16. Image reconstruction from multiple fan-beam projections

    International Nuclear Information System (INIS)

    Jelinek, J.; Overton, T.R.

    1984-01-01

    Special-purpose third-generation fan-beam CT systems can be greatly simplified by limiting the number of detectors, but this requires a different mode of data collection to provide a set of projections appropriate to the required spatial resolution in the reconstructed image. Repeated rotation of the source-detector fan, combined with shift of the detector array and perhaps offset of the source with respect to the fan's axis after each 360 0 rotation(cycle), provides a fairly general pattern of projection space filling. The authors' investigated the problem of optimal data-collection geometry for a multiple-rotation fan-beam scanner and of corresponding reconstruction algorithm

  17. IMAGE CONSTRUCTION TO AUTOMATION OF PROJECTIVE TECHNIQUES FOR PSYCHOPHYSIOLOGICAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Natalia Pavlova

    2018-04-01

    Full Text Available The search for a solution of automation of the process of assessment of a psychological analysis of the person drawings created by it from an available set of some templates are presented at this article. It will allow to reveal more effectively infringements of persons mentality. In particular, such decision can be used for work with children who possess the developed figurative thinking, but are not yet capable of an accurate statement of the thoughts and experiences. For automation of testing by using a projective method, we construct interactive environment for visualization of compositions of the several images and then analyse

  18. Final Project Report: Imaging Fault Zones Using a Novel Elastic Reverse-Time Migration Imaging Technique

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lianjie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chen, Ting [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tan, Sirui [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lin, Youzuo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gao, Kai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-10

    Imaging fault zones and fractures is crucial for geothermal operators, providing important information for reservoir evaluation and management strategies. However, there are no existing techniques available for directly and clearly imaging fault zones, particularly for steeply dipping faults and fracture zones. In this project, we developed novel acoustic- and elastic-waveform inversion methods for high-resolution velocity model building. In addition, we developed acoustic and elastic reverse-time migration methods for high-resolution subsurface imaging of complex subsurface structures and steeply-dipping fault/fracture zones. We first evaluated and verified the improved capabilities of our newly developed seismic inversion and migration imaging methods using synthetic seismic data. Our numerical tests verified that our new methods directly image subsurface fracture/fault zones using surface seismic reflection data. We then applied our novel seismic inversion and migration imaging methods to a field 3D surface seismic dataset acquired at the Soda Lake geothermal field using Vibroseis sources. Our migration images of the Soda Lake geothermal field obtained using our seismic inversion and migration imaging algorithms revealed several possible fault/fracture zones. AltaRock Energy, Inc. is working with Cyrq Energy, Inc. to refine the geologic interpretation at the Soda Lake geothermal field. Trenton Cladouhos, Senior Vice President R&D of AltaRock, was very interested in our imaging results of 3D surface seismic data from the Soda Lake geothermal field. He planed to perform detailed interpretation of our images in collaboration with James Faulds and Holly McLachlan of University of Nevada at Reno. Using our high-resolution seismic inversion and migration imaging results can help determine the optimal locations to drill wells for geothermal energy production and reduce the risk of geothermal exploration.

  19. A fractured rock geophysical toolbox method selection tool

    Science.gov (United States)

    Day-Lewis, F. D.; Johnson, C.D.; Slater, L.D.; Robinson, J.L.; Williams, J.H.; Boyden, C.L.; Werkema, D.D.; Lane, J.W.

    2016-01-01

    Geophysical technologies have the potential to improve site characterization and monitoring in fractured rock, but the appropriate and effective application of geophysics at a particular site strongly depends on project goals (e.g., identifying discrete fractures) and site characteristics (e.g., lithology). No method works at every site or for every goal. New approaches are needed to identify a set of geophysical methods appropriate to specific project goals and site conditions while considering budget constraints. To this end, we present the Excel-based Fractured-Rock Geophysical Toolbox Method Selection Tool (FRGT-MST). We envision the FRGT-MST (1) equipping remediation professionals with a tool to understand what is likely to be realistic and cost-effective when contracting geophysical services, and (2) reducing applications of geophysics with unrealistic objectives or where methods are likely to fail.

  20. Geophysical Field Theory

    International Nuclear Information System (INIS)

    Eloranta, E.

    2003-11-01

    The geophysical field theory includes the basic principles of electromagnetism, continuum mechanics, and potential theory upon which the computational modelling of geophysical phenomena is based on. Vector analysis is the main mathematical tool in the field analyses. Electrostatics, stationary electric current, magnetostatics, and electrodynamics form a central part of electromagnetism in geophysical field theory. Potential theory concerns especially gravity, but also electrostatics and magnetostatics. Solid state mechanics and fluid mechanics are central parts in continuum mechanics. Also the theories of elastic waves and rock mechanics belong to geophysical solid state mechanics. The theories of geohydrology and mass transport form one central field theory in geophysical fluid mechanics. Also heat transfer is included in continuum mechanics. (orig.)

  1. Fundamentals of Geophysics

    Science.gov (United States)

    Lowrie, William

    1997-10-01

    This unique textbook presents a comprehensive overview of the fundamental principles of geophysics. Unlike most geophysics textbooks, it combines both the applied and theoretical aspects to the subject. The author explains complex geophysical concepts using abundant diagrams, a simplified mathematical treatment, and easy-to-follow equations. After placing the Earth in the context of the solar system, he describes each major branch of geophysics: gravitation, seismology, dating, thermal and electrical properties, geomagnetism, paleomagnetism and geodynamics. Each chapter begins with a summary of the basic physical principles, and a brief account of each topic's historical evolution. The book will satisfy the needs of intermediate-level earth science students from a variety of backgrounds, while at the same time preparing geophysics majors for continued study at a higher level.

  2. Nonnegative least-squares image deblurring: improved gradient projection approaches

    Science.gov (United States)

    Benvenuto, F.; Zanella, R.; Zanni, L.; Bertero, M.

    2010-02-01

    The least-squares approach to image deblurring leads to an ill-posed problem. The addition of the nonnegativity constraint, when appropriate, does not provide regularization, even if, as far as we know, a thorough investigation of the ill-posedness of the resulting constrained least-squares problem has still to be done. Iterative methods, converging to nonnegative least-squares solutions, have been proposed. Some of them have the 'semi-convergence' property, i.e. early stopping of the iteration provides 'regularized' solutions. In this paper we consider two of these methods: the projected Landweber (PL) method and the iterative image space reconstruction algorithm (ISRA). Even if they work well in many instances, they are not frequently used in practice because, in general, they require a large number of iterations before providing a sensible solution. Therefore, the main purpose of this paper is to refresh these methods by increasing their efficiency. Starting from the remark that PL and ISRA require only the computation of the gradient of the functional, we propose the application to these algorithms of special acceleration techniques that have been recently developed in the area of the gradient methods. In particular, we propose the application of efficient step-length selection rules and line-search strategies. Moreover, remarking that ISRA is a scaled gradient algorithm, we evaluate its behaviour in comparison with a recent scaled gradient projection (SGP) method for image deblurring. Numerical experiments demonstrate that the accelerated methods still exhibit the semi-convergence property, with a considerable gain both in the number of iterations and in the computational time; in particular, SGP appears definitely the most efficient one.

  3. Remote Imaging Projects In Research And Astrophotography With Starpals

    Science.gov (United States)

    Fischer, Audrey; Kingan, J.

    2008-05-01

    StarPals is a nascent non-profit organization with the goal of providing opportunities for international collaboration between students of all ages within space science research. We believe that by encouraging an interest in the cosmos, the one thing that is truly Universal, from a young age, students will not only further their knowledge of and interest in science but will learn valuable teamwork and life skills. The goal is to foster respect, understanding and appreciation of cultural diversity among all StarPals participants, whether students, teachers, or mentors. StarPals aims to inspire students by providing opportunities in which, more than simply visualizing themselves as research scientists, they can actually become one. The technologies of robotic telescopes, videoconferencing, and online classrooms are expanding the possibilities like never before. In honor of IYA2009, StarPals would like to encourage 400 schools to participate on a global scale in astronomy/cosmology research on various concurrent projects. We will offer in-person or online workshops and training sessions to teach the teachers. We will be seeking publication in scientific journals for some student research. For our current project, the Double Stars Challenge, students use the robotic telescopes to take a series of four images of one of 30 double stars from a list furnished by the US Naval Observatory and then use MPO Canopus software to take distance and position angle measurements. StarPals provides students with hands-on training, telescope time, and software to complete the imaging and measuring. A paper will be drafted from our research data and submitted to the Journal of Double Star Observations. The kids who participate in this project may potentially be the youngest contributors to an article in a vetted scientific journal. Kids rapidly adapt and improve their computer skills operating these telescopes and discover for themselves that science is COOL!

  4. Image applications for coastal resource planning: Elkhorn Slough Pilot Project

    Science.gov (United States)

    Kvitek, Rikk G.; Sharp, Gary D.; VanCoops, Jonathan; Fitzgerald, Michael

    1995-01-01

    The purpose of this project has been to evaluate the utility of digital spectral imagery at two levels of resolution for large scale, accurate, auto-classification of land cover along the Central California Coast. Although remote sensing technology offers obvious advantages over on-the-ground mapping, there are substantial trade-offs that must be made between resolving power and costs. Higher resolution images can theoretically be used to identify smaller habitat patches, but they usually require more scenes to cover a given area and processing these images is computationally intense requiring much more computer time and memory. Lower resolution images can cover much larger areas, are less costly to store, process, and manipulate, but due to their larger pixel size can lack the resolving power of the denser images. This lack of resolving power can be critical in regions such as the Central California Coast where important habitat change often occurs on a scale of 10 meters. Our approach has been to compare vegetation and habitat classification results from two aircraft-based spectral scenes covering the same study area but at different levels of resolution with a previously produced ground-truthed land cover base map of the area. Both of the spectral images used for this project were of significantly higher resolution than the satellite-based LandSat scenes used in the C-CAP program. The lower reaches of the Elkhorn Slough watershed was chosen as an ideal study site because it encompasses a suite of important vegetation types and habitat loss processes characteristic of the central coast region. Dramatic habitat alterations have and are occurring within the Elkhorn Slough drainage area, including erosion and sedimentation, land use conversion, wetland loss, and incremental loss due to development and encroachnnent by agriculture. Additonally, much attention has already been focused on the Elkhorn Slough due to its status as a National Marine Education and Research

  5. Multiview Discriminative Geometry Preserving Projection for Image Classification

    Directory of Open Access Journals (Sweden)

    Ziqiang Wang

    2014-01-01

    Full Text Available In many image classification applications, it is common to extract multiple visual features from different views to describe an image. Since different visual features have their own specific statistical properties and discriminative powers for image classification, the conventional solution for multiple view data is to concatenate these feature vectors as a new feature vector. However, this simple concatenation strategy not only ignores the complementary nature of different views, but also ends up with “curse of dimensionality.” To address this problem, we propose a novel multiview subspace learning algorithm in this paper, named multiview discriminative geometry preserving projection (MDGPP for feature extraction and classification. MDGPP can not only preserve the intraclass geometry and interclass discrimination information under a single view, but also explore the complementary property of different views to obtain a low-dimensional optimal consensus embedding by using an alternating-optimization-based iterative algorithm. Experimental results on face recognition and facial expression recognition demonstrate the effectiveness of the proposed algorithm.

  6. A Hydrologic-geophysical Method for Characterizing Flow and Transport Processes Within The Vadose Zone

    International Nuclear Information System (INIS)

    Alumbaugh, David; LaBrecque, Douglas; Brainard, James; Yeh, T.C.-Jim

    2004-01-01

    The primary purpose of this project was to employ two geophysical imaging techniques, electrical resistivity tomography and cross-borehole ground penetrating radar, to image a controlled infiltration of a saline tracer under unsaturated flow conditions. The geophysical techniques have been correlated to other more traditional hydrologic measurements including neutron moisture measurements and induction conductivity logs. Images that resulted during two successive infiltrations indicate the development of what appear to be preferential pathways through the finer grained materials, although the results could also be produced by cationic capture of free ions in clays. In addition the site as well as the developing solute plume exhibits electrical anisotropy which is likely related to flow properties. However the geologic significance of this phenomenon is still under investigation

  7. A Hydrologic-geophysical Method for Characterizing Flow and Transport Processes Within The Vadose Zone

    Energy Technology Data Exchange (ETDEWEB)

    David Alumbaugh; Douglas LaBrecque; James Brainard; T.C. (Jim) Yeh

    2004-01-22

    The primary purpose of this project was to employ two geophysical imaging techniques, electrical resistivity tomography and cross-borehole ground penetrating radar, to image a controlled infiltration of a saline tracer under unsaturated flow conditions. The geophysical techniques have been correlated to other more traditional hydrologic measurements including neutron moisture measurements and induction conductivity logs. Images that resulted during two successive infiltrations indicate the development of what appear to be preferential pathways through the finer grained materials, although the results could also be produced by cationic capture of free ions in clays. In addition the site as well as the developing solute plume exhibits electrical anisotropy which is likely related to flow properties. However the geologic significance of this phenomenon is still under investigation.

  8. Summary and evaluation of existing geological and geophysical data near prospective surface facilities in Midway Valley, Yucca Mountain Project, Nye County, Nevada

    International Nuclear Information System (INIS)

    Gibson, J.D.; Swan, F.H.; Wesling, J.R.; Bullard, T.F.; Perman, R.C.; Angell, M.M.; DiSilvestro, L.A.

    1992-01-01

    Midway Valley, located at the eastern base of the Yucca Mountain in southwestern Nevada, is the preferred location of the surface facilities for the potential high-level nuclear waste repository at Yucca Mountain. One goal in siting these surface facilities is to avoid faults that could produce relative displacements in excess of 5 cm in the foundations of the waste-handling buildings. This study reviews existing geologic and geophysical data that can be used to assess the potential for surface fault rupture within Midway Valley. Dominant tectonic features in Midway Valley are north-trending, westward-dipping normal faults along the margins of the valley: the Bow Ridge fault to the west and the Paintbrush Canyon fault to the east. Published estimates of average Quaternary slip rates for these faults are very low but the age of most recent displacement and the amount of displacement per event are largely unknown. Surface mapping and interpretive cross sections, based on limited drillhole and geophysical data, suggest that additional normal faults, including the postulated Midway Valley fault, may exist beneath the Quaternary/Tertiary fill within the valley. Existing data, however, are inadequate to determine the location, recency, and geometry of this faulting. To confidently assess the potential for significant Quaternary faulting in Midway Valley, additional data are needed that define the stratigraphy and structure of the strata beneath the valley, characterize the Quaternary soils and surfaces, and establish the age of faulting. The use of new and improved geophysical techniques, combined with a drilling program, offers the greatest potential for resolving subsurface structure in the valley. Mapping of surficial geologic units and logging of soil pits and trenches within these units must be completed, using accepted state-of-the-art practices supported by multiple quantitative numerical and relative age-dating techniques

  9. Tomographic image via background subtraction using an x-ray projection image and a priori computed tomography

    International Nuclear Information System (INIS)

    Zhang Jin; Yi Byongyong; Lasio, Giovanni; Suntharalingam, Mohan; Yu, Cedric

    2009-01-01

    Kilovoltage x-ray projection images (kV images for brevity) are increasingly available in image guided radiotherapy (IGRT) for patient positioning. These images are two-dimensional (2D) projections of a three-dimensional (3D) object along the x-ray beam direction. Projecting a 3D object onto a plane may lead to ambiguities in the identification of anatomical structures and to poor contrast in kV images. Therefore, the use of kV images in IGRT is mainly limited to bony landmark alignments. This work proposes a novel subtraction technique that isolates a slice of interest (SOI) from a kV image with the assistance of a priori information from a previous CT scan. The method separates structural information within a preselected SOI by suppressing contributions to the unprocessed projection from out-of-SOI-plane structures. Up to a five-fold increase in the contrast-to-noise ratios (CNRs) was observed in selected regions of the isolated SOI, when compared to the original unprocessed kV image. The tomographic image via background subtraction (TIBS) technique aims to provide a quick snapshot of the slice of interest with greatly enhanced image contrast over conventional kV x-ray projections for fast and accurate image guidance of radiation therapy. With further refinements, TIBS could, in principle, provide real-time tumor localization using gantry-mounted x-ray imaging systems without the need for implanted markers.

  10. Tomography of images with poisson miose: pre-processing of projections

    International Nuclear Information System (INIS)

    Furuie, S.S.

    1989-01-01

    This work present an alternative approach in order to reconstruct images with low signal to noise ratio. Basically it consist of smoothing projections taking into account that the noise is Poisson. These filtered projections are used to reconstruct the original image, applying direct Fourier method. This approach is compared with convolution back projection and EM (Expectation-Maximization). (author) [pt

  11. National Land Imaging Requirements (NLIR) Pilot Project summary report: summary of moderate resolution imaging user requirements

    Science.gov (United States)

    Vadnais, Carolyn; Stensaas, Gregory

    2014-01-01

    Under the National Land Imaging Requirements (NLIR) Project, the U.S. Geological Survey (USGS) is developing a functional capability to obtain, characterize, manage, maintain and prioritize all Earth observing (EO) land remote sensing user requirements. The goal is a better understanding of community needs that can be supported with land remote sensing resources, and a means to match needs with appropriate solutions in an effective and efficient way. The NLIR Project is composed of two components. The first component is focused on the development of the Earth Observation Requirements Evaluation System (EORES) to capture, store and analyze user requirements, whereas, the second component is the mechanism and processes to elicit and document the user requirements that will populate the EORES. To develop the second component, the requirements elicitation methodology was exercised and refined through a pilot project conducted from June to September 2013. The pilot project focused specifically on applications and user requirements for moderate resolution imagery (5–120 meter resolution) as the test case for requirements development. The purpose of this summary report is to provide a high-level overview of the requirements elicitation process that was exercised through the pilot project and an early analysis of the moderate resolution imaging user requirements acquired to date to support ongoing USGS sustainable land imaging study needs. The pilot project engaged a limited set of Federal Government users from the operational and research communities and therefore the information captured represents only a subset of all land imaging user requirements. However, based on a comparison of results, trends, and analysis, the pilot captured a strong baseline of typical applications areas and user needs for moderate resolution imagery. Because these results are preliminary and represent only a sample of users and application areas, the information from this report should only

  12. FINAL PROJECT REPORT: A Geophysical Characterization & Monitoring Strategy for Determining Hydrologic Processes in the Hyporheic Corridor at the Hanford 300-Area

    Energy Technology Data Exchange (ETDEWEB)

    Lee Slater

    2011-08-15

    The primary objective of this research was to advance the prediction of solute transport between the Uranium contaminated Hanford aquifer and the Columbia River at the Hanford 300 Area by improving understanding of how fluctuations in river stage, combined with subsurface heterogeneity, impart spatiotemporal complexity to solute exchange along the Columbia River corridor. Our work explored the use of continuous waterborne electrical imaging (CWEI), in conjunction with fiber-optic distributed temperature sensor (FO-DTS) and time-lapse resistivity monitoring, to improve the conceptual model for how groundwater/surface water exchange regulates uranium transport. We also investigated how resistivity and induced polarization can be used to generate spatially rich estimates of the variation in depth to the Hanford-Ringold (H-R) contact between the river and the 300 Area Integrated Field Research Challenge (IFRC) site. Inversion of the CWEI datasets (a data rich survey containing ~60,000 measurements) provided predictions of the distributions of electrical resistivity and polarizability, from which the spatial complexity of the primary hydrogeologic units along the river corridor was reconstructed. Variation in the depth to the interface between the overlying coarse-grained, high permeability Hanford Formation and the underlying finer-grained, less permeable Ringold Formation, an important contact that limits vertical migration of contaminants, has been resolved along ~3 km of the river corridor centered on the IFRC site in the Hanford 300 Area. Spatial variability in the thickness of the Hanford Formation captured in the CWEI datasets indicates that previous studies based on borehole projections and drive-point and multi-level sampling likely overestimate the contributing area for uranium exchange within the Columbia River at the Hanford 300 Area. Resistivity and induced polarization imaging between the river and the 300 Area IFRC further imaged spatial variability in

  13. Maximum intensity projection MR angiography using shifted image data

    International Nuclear Information System (INIS)

    Machida, Yoshio; Ichinose, Nobuyasu; Hatanaka, Masahiko; Goro, Takehiko; Kitake, Shinichi; Hatta, Junicchi.

    1992-01-01

    The quality of MR angiograms has been significantly improved in past several years. Spatial resolution, however, is not sufficient for clinical use. On the other hand, MR image data can be filled at anywhere using Fourier shift theorem, and the quality of multi-planar reformed image has been reported to be improved remarkably using 'shifted data'. In this paper, we have clarified the efficiency of 'shifted data' for maximum intensity projection MR angiography. Our experimental studies and theoretical consideration showd that the quality of MR angiograms has been significantly improved using 'shifted data' as follows; 1) remarkable reduction of mosaic artifact, 2) improvement of spatial continuity for the blood vessels, and 3) reduction of variance for the signal intensity along the blood vessels. In other words, the angiograms looks much 'finer' than conventional ones, although the spatial resolution is not improved theoretically. Furthermore, we found the quality of MR angiograms dose not improve significantly with the 'shifted data' more than twice as dense as ordinal ones. (author)

  14. Radioactivity and geophysics

    International Nuclear Information System (INIS)

    Radvanyi, P.

    1992-01-01

    The paper recalls a few steps of the introduction of radioactivity in geophysics and astrophysics: contribution of radioelements to energy balance of the Earth, age of the Earth based on radioactive disintegration and the discovery of cosmic radiations

  15. Geophysical Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Geophysical Research Facility (GRF) is a 60 ft long × 22 ft wide × 7 ft deep concrete basin at CRREL for fresh or saltwater investigations and can be temperature...

  16. Geophysical borehole logging

    International Nuclear Information System (INIS)

    McCann, D.; Barton, K.J.; Hearn, K.

    1981-08-01

    Most of the available literature on geophysical borehole logging refers to studies carried out in sedimentary rocks. It is only in recent years that any great interest has been shown in geophysical logging in boreholes in metamorphic and igneous rocks following the development of research programmes associated with geothermal energy and nuclear waste disposal. This report is concerned with the programme of geophysical logging carried out on the three deep boreholes at Altnabreac, Caithness, to examine the effectiveness of these methods in crystalline rock. Of particular importance is the assessment of the performance of the various geophysical sondes run in the boreholes in relation to the rock mass properties. The geophysical data can be used to provide additional in-situ information on the geological, hydrogeological and engineering properties of the rock mass. Fracturing and weathering in the rock mass have a considerable effect on both the design parameters for an engineering structure and the flow of water through the rock mass; hence, the relation between the geophysical properties and the degree of fracturing and weathering is examined in some detail. (author)

  17. A segmentation algorithm based on image projection for complex text layout

    Science.gov (United States)

    Zhu, Wangsheng; Chen, Qin; Wei, Chuanyi; Li, Ziyang

    2017-10-01

    Segmentation algorithm is an important part of layout analysis, considering the efficiency advantage of the top-down approach and the particularity of the object, a breakdown of projection layout segmentation algorithm. Firstly, the algorithm will algorithm first partitions the text image, and divided into several columns, then for each column scanning projection, the text image is divided into several sub regions through multiple projection. The experimental results show that, this method inherits the projection itself and rapid calculation speed, but also can avoid the effect of arc image information page segmentation, and also can accurate segmentation of the text image layout is complex.

  18. Color correction of projected image on color-screen for mobile beam-projector

    Science.gov (United States)

    Son, Chang-Hwan; Sung, Soo-Jin; Ha, Yeong-Ho

    2008-01-01

    With the current trend of digital convergence in mobile phones, mobile manufacturers are researching how to develop a mobile beam-projector to cope with the limitations of a small screen size and to offer a better feeling of movement while watching movies or satellite broadcasting. However, mobile beam-projectors may project an image on arbitrary surfaces, such as a colored wall and paper, not on a white screen mainly used in an office environment. Thus, color correction method for the projected image is proposed to achieve good image quality irrespective of the surface colors. Initially, luminance values of original image transformed into the YCbCr space are changed to compensate for spatially nonuniform luminance distribution of arbitrary surface, depending on the pixel values of surface image captured by mobile camera. Next, the chromaticity values for each surface and white-screen image are calculated using the ratio of the sum of three RGB values to one another. Then their chromaticity ratios are multiplied by converted original image through an inverse YCbCr matrix to reduce an influence of modulating the appearance of projected image due to spatially different reflectance on the surface. By projecting corrected original image on a texture pattern or single color surface, the image quality of projected image can be improved more, as well as that of projected image on white screen.

  19. Reconstruction of a cone-beam CT image via forward iterative projection matching

    International Nuclear Information System (INIS)

    Brock, R. Scott; Docef, Alen; Murphy, Martin J.

    2010-01-01

    Purpose: To demonstrate the feasibility of reconstructing a cone-beam CT (CBCT) image by deformably altering a prior fan-beam CT (FBCT) image such that it matches the anatomy portrayed in the CBCT projection data set. Methods: A prior FBCT image of the patient is assumed to be available as a source image. A CBCT projection data set is obtained and used as a target image set. A parametrized deformation model is applied to the source FBCT image, digitally reconstructed radiographs (DRRs) that emulate the CBCT projection image geometry are calculated and compared to the target CBCT projection data, and the deformation model parameters are adjusted iteratively until the DRRs optimally match the CBCT projection data set. The resulting deformed FBCT image is hypothesized to be an accurate representation of the patient's anatomy imaged by the CBCT system. The process is demonstrated via numerical simulation. A known deformation is applied to a prior FBCT image and used to create a synthetic set of CBCT target projections. The iterative projection matching process is then applied to reconstruct the deformation represented in the synthetic target projections; the reconstructed deformation is then compared to the known deformation. The sensitivity of the process to the number of projections and the DRR/CBCT projection mismatch is explored by systematically adding noise to and perturbing the contrast of the target projections relative to the iterated source DRRs and by reducing the number of projections. Results: When there is no noise or contrast mismatch in the CBCT projection images, a set of 64 projections allows the known deformed CT image to be reconstructed to within a nRMS error of 1% and the known deformation to within a nRMS error of 7%. A CT image nRMS error of less than 4% is maintained at noise levels up to 3% of the mean projection intensity, at which the deformation error is 13%. At 1% noise level, the number of projections can be reduced to 8 while maintaining

  20. Geophysical characterization of subsurface barriers

    International Nuclear Information System (INIS)

    Borns, D.J.

    1995-08-01

    An option for controlling contaminant migration from plumes and buried waste sites is to construct a subsurface barrier of a low-permeability material. The successful application of subsurface barriers requires processes to verify the emplacement and effectiveness of barrier and to monitor the performance of a barrier after emplacement. Non destructive and remote sensing techniques, such as geophysical methods, are possible technologies to address these needs. The changes in mechanical, hydrologic and chemical properties associated with the emplacement of an engineered barrier will affect geophysical properties such a seismic velocity, electrical conductivity, and dielectric constant. Also, the barrier, once emplaced and interacting with the in situ geologic system, may affect the paths along which electrical current flows in the subsurface. These changes in properties and processes facilitate the detection and monitoring of the barrier. The approaches to characterizing and monitoring engineered barriers can be divided between (1) methods that directly image the barrier using the contrasts in physical properties between the barrier and the host soil or rock and (2) methods that reflect flow processes around or through the barrier. For example, seismic methods that delineate the changes in density and stiffness associated with the barrier represents a direct imaging method. Electrical self potential methods and flow probes based on heat flow methods represent techniques that can delineate the flow path or flow processes around and through a barrier

  1. Software complex for geophysical data visualization

    Science.gov (United States)

    Kryukov, Ilya A.; Tyugin, Dmitry Y.; Kurkin, Andrey A.; Kurkina, Oxana E.

    2013-04-01

    The effectiveness of current research in geophysics is largely determined by the degree of implementation of the procedure of data processing and visualization with the use of modern information technology. Realistic and informative visualization of the results of three-dimensional modeling of geophysical processes contributes significantly into the naturalness of physical modeling and detailed view of the phenomena. The main difficulty in this case is to interpret the results of the calculations: it is necessary to be able to observe the various parameters of the three-dimensional models, build sections on different planes to evaluate certain characteristics and make a rapid assessment. Programs for interpretation and visualization of simulations are spread all over the world, for example, software systems such as ParaView, Golden Software Surfer, Voxler, Flow Vision and others. However, it is not always possible to solve the problem of visualization with the help of a single software package. Preprocessing, data transfer between the packages and setting up a uniform visualization style can turn into a long and routine work. In addition to this, sometimes special display modes for specific data are required and existing products tend to have more common features and are not always fully applicable to certain special cases. Rendering of dynamic data may require scripting languages that does not relieve the user from writing code. Therefore, the task was to develop a new and original software complex for the visualization of simulation results. Let us briefly list of the primary features that are developed. Software complex is a graphical application with a convenient and simple user interface that displays the results of the simulation. Complex is also able to interactively manage the image, resize the image without loss of quality, apply a two-dimensional and three-dimensional regular grid, set the coordinate axes with data labels and perform slice of data. The

  2. Image/patient registration from (partial) projection data by the Fourier phase matching method

    International Nuclear Information System (INIS)

    Weiguo Lu; You, J.

    1999-01-01

    A technique for 2D or 3D image/patient registration, PFPM (projection based Fourier phase matching method), is proposed. This technique provides image/patient registration directly from sequential tomographic projection data. The method can also deal with image files by generating 2D Radon transforms slice by slice. The registration in projection space is done by calculating a Fourier invariant (FI) descriptor for each one-dimensional projection datum, and then registering the FI descriptor by the Fourier phase matching (FPM) method. The algorithm has been tested on both synthetic and experimental data. When dealing with translated, rotated and uniformly scaled 2D image registration, the performance of the PFPM method is comparable to that of the IFPM (image based Fourier phase matching) method in robustness, efficiency, insensitivity to the offset between images, and registration time. The advantages of the former are that subpixel resolution is feasible, and it is more insensitive to image noise due to the averaging effect of the projection acquisition. Furthermore, the PFPM method offers the ability to generalize to 3D image/patient registration and to register partial projection data. By applying patient registration directly from tomographic projection data, image reconstruction is not needed in the therapy set-up verification, thus reducing computational time and artefacts. In addition, real time registration is feasible. Registration from partial projection data meets the geometry and dose requirements in many application cases and makes dynamic set-up verification possible in tomotherapy. (author)

  3. Collaborative Tracking of Image Features Based on Projective Invariance

    Science.gov (United States)

    Jiang, Jinwei

    -mode sensors for improving the flexibility and robustness of the system. From the experimental results during three field tests for the LASOIS system, we observed that most of the errors in the image processing algorithm are caused by the incorrect feature tracking. This dissertation addresses the feature tracking problem in image sequences acquired from cameras. Despite many alternatives to feature tracking problem, iterative least squares solution solving the optical flow equation has been the most popular approach used by many in the field. This dissertation attempts to leverage the former efforts to enhance feature tracking methods by introducing a view geometric constraint to the tracking problem, which provides collaboration among features. In contrast to alternative geometry based methods, the proposed approach provides an online solution to optical flow estimation in a collaborative fashion by exploiting Horn and Schunck flow estimation regularized by view geometric constraints. Proposed collaborative tracker estimates the motion of a feature based on the geometry of the scene and how the other features are moving. Alternative to this approach, a new closed form solution to tracking that combines the image appearance with the view geometry is also introduced. We particularly use invariants in the projective coordinates and conjecture that the traditional appearance solution can be significantly improved using view geometry. The geometric constraint is introduced by defining a new optical flow equation which exploits the scene geometry from a set drawn from tracked features. At the end of each tracking loop the quality of the tracked features is judged using both appearance similarity and geometric consistency. Our experiments demonstrate robust tracking performance even when the features are occluded or they undergo appearance changes due to projective deformation of the template. The proposed collaborative tracking method is also tested in the visual navigation

  4. Predictive geophysics: geochemical simulations to geophysical targets

    Science.gov (United States)

    Chopping, R. G.; Cleverley, J.

    2017-12-01

    With an increasing focus on deep exploration for covered targets, new methods are required to target mineral systems under cover. Geophysical responses are driven by physical property contrasts; for example, density contrasts provide a gravity signal, acoustic impedance contrasts provide a seismic reflection signal. In turn, the physical properties for basement, crystalline rocks which host the vast majority of mineral systems are determined almost wholly by the mineralogy of the rocks in question. Mineral systems, through the transport of heat and reactive fluids, will serve to modify the physical properties of country rock as they chemically alter the hosting strata. To understand these changes, we have performed 2D reactive transport modelling that simulates the formation of Archean gold deposits of the Yilgarn Craton, Western Australia. From this, we derive a model of mineralogy that we can use to predict the density, magnetic susceptibility and seismic reflection changes associated with ore formation. It is then possible to predict the gravity, magnetic and seismic reflection responses associated with these deposits. Scenario mapping, such as testing the ability to resolve buried ore bodies or the geophysical survey spacing required to resolve the mineral system, can be performed to produce geophysical targets from these geochemical simulations. We find that there is a gravity response of around 9% of the unaltered response for deposits even buried by 1km of cover, and there is a magnetic spike associated with proximal alteration of the ore system. Finally, seismic reflection response is mostly characterised by additional reflections along faults that plumb the alteration system.

  5. Airborne Geophysical/Geological Mineral Inventory CIP Program

    National Research Council Canada - National Science Library

    1999-01-01

    The Airborne-Geophysical/Geological Mineral Inventory project is a special multi-year investment to expand the knowledge base of Alaska's mineral resources and catalyze private-sector mineral development...

  6. What's down below? Current and potential future applications of geophysical techniques to identify subsurface permafrost conditions (Invited)

    Science.gov (United States)

    Douglas, T. A.; Bjella, K.; Campbell, S. W.

    2013-12-01

    For infrastructure design, operations, and maintenance requirements in the North the ability to accurately and efficiently detect the presence (or absence) of ground ice in permafrost terrains is a serious challenge. Ground ice features including ice wedges, thermokarst cave-ice, and segregation ice are present in a variety of spatial scales and patterns. Currently, most engineering applications use borehole logging and sampling to extrapolate conditions at the point scale. However, there is high risk of over or under estimating the presence of frozen or unfrozen features when relying on borehole information alone. In addition, boreholes are costly, especially for planning linear structures like roads or runways. Predicted climate warming will provide further challenges for infrastructure development and transportation operations where permafrost degradation occurs. Accurately identifying the subsurface character in permafrost terrains will allow engineers and planners to cost effectively create novel infrastructure designs to withstand the changing environment. There is thus a great need for a low cost rapidly deployable, spatially extensive means of 'measuring' subsurface conditions. Geophysical measurements, both terrestrial and airborne, have strong potential to revolutionize our way of mapping subsurface conditions. Many studies in continuous and discontinuous permafrost have used geophysical measurements to identify discrete features and repeatable patterns in the subsurface. The most common measurements include galvanic and capacitive coupled resistivity, ground penetrating radar, and multi frequency electromagnetic induction techniques. Each of these measurements has strengths, weaknesses, and limitations. By combining horizontal geophysical measurements, downhole geophysics, multispectral remote sensing images, LiDAR measurements, and soil and vegetation mapping we can start to assemble a holistic view of how surface conditions and standoff measurements

  7. From whole-body counting to imaging: The computer aided collimation gamma camera project (CACAO)

    Energy Technology Data Exchange (ETDEWEB)

    Jeanguillaume, C.; Begot, S.; Quartuccio, M.; Douiri, A.; Ballongue, P

    2000-07-01

    Whole-body counting is the method of choice for in vivo detection of contamination. To extend this well established method, the possible advantages of imaging radiocontaminants are examined. The use of the CACAO project is then studied. A comparison of simulated reconstructed images obtained by the CACAO project and by a conventional gamma camera used in nuclear medicine follows. Imaging a radionuclide contaminant with a geometrical sensitivity of 10{sup -2} seems possible in the near future. (author)

  8. From whole-body counting to imaging: The computer aided collimation gamma camera project (CACAO)

    International Nuclear Information System (INIS)

    Jeanguillaume, C.; Begot, S.; Quartuccio, M.; Douiri, A.; Ballongue, P.

    2000-01-01

    Whole-body counting is the method of choice for in vivo detection of contamination. To extend this well established method, the possible advantages of imaging radiocontaminants are examined. The use of the CACAO project is then studied. A comparison of simulated reconstructed images obtained by the CACAO project and by a conventional gamma camera used in nuclear medicine follows. Imaging a radionuclide contaminant with a geometrical sensitivity of 10 -2 seems possible in the near future. (author)

  9. Geophysical modeling across Inner and Outer Western Carpathians in Eastern Slovakia

    Science.gov (United States)

    Vozar, J.; Bezak, V.; Bielik, M.; Majcin, D.; Vajda, P.; Bilcik, D.

    2017-12-01

    We present a multidimensional geophysical modelling of Central and Eastern Slovakia in the area of contact zone between the Inner and Outer Western Carpathians, and the East Slovakian Basin. Our crustal and lithospheric studies are based on geophysical data collected during CELEBRATION 2000 project and project THERMES. The new magnetotelluric (MT) multidimensional modelling is combined with seismic 2D wide angle refraction profiles and gravimetric modelling. Together with thermal information gathered from the area we constructed new integrated geophysical models of structures included in the evolution of the Carpathian orogen. Preliminary results of MT modelling in Eastern Slovakia suggest more electrically conductive structures in the middle and lower crustal depths in comparison with Central Slovakia, where we observed structures dominated by resistive complexes overlaid by conductive sedimentary formations. The higher conductivities below the East Slovakian Basin restrict penetration depth of the geoelectrical images. The electrically conductive structures are connected with tectono-thermal development in Neogene and presence of volcanic activity. Another significant conductive anomaly is imaged along the contact zone between Inner and Outer Western Carpathians in depths of about 10 - 20km, which is known as the Carpathian Conductivity Anomaly (CCA). In order to improve the depth resolution of MT models we decided to combine geoelectrical images with density and velocity models of the area. We used integrated petrological and geophysical modeling code to obtain thermally consistent lithospheric scale models of the area. A possible preliminary geological interpretation of the northern segment of investigated area suggests a resistive European platform below conductive flysch sediments. The boundary between Inner and Outer Carpthians represented by the Klippen Belt on the surface is changed to the CCA in higher depths. In the direction to the south there are

  10. Surface Geophysical Exploration - Compendium Document

    International Nuclear Information System (INIS)

    Rucker, D.F.; Myers, D.A.

    2011-01-01

    This report documents the evolution of the surface geophysical exploration (SGE) program and highlights some of the most recent successes in imaging conductive targets related to past leaks within and around Hanford's tank farms. While it is noted that the SGE program consists of multiple geophysical techniques designed to (1) locate near surface infrastructure that may interfere with (2) subsurface plume mapping, the report will focus primarily on electrical resistivity acquisition and processing for plume mapping. Due to the interferences from the near surface piping network, tanks, fences, wells, etc., the results of the three-dimensional (3D) reconstruction of electrical resistivity was more representative of metal than the high ionic strength plumes. Since the first deployment, the focus of the SGE program has been to acquire and model the best electrical resistivity data that minimizes the influence of buried metal objects. Toward that goal, two significant advances have occurred: (1) using the infrastructure directly in the acquisition campaign and (2) placement of electrodes beneath the infrastructure. The direct use of infrastructure was successfully demonstrated at T farm by using wells as long electrodes (Rucker et al., 2010, 'Electrical-Resistivity Characterization of an Industrial Site Using Long Electrodes'). While the method was capable of finding targets related to past releases, a loss of vertical resolution was the trade-off. The burying of electrodes below the infrastructure helped to increase the vertical resolution, as long as a sufficient number of electrodes are available for the acquisition campaign.

  11. SURFACE GEOPHYSICAL EXPLORATION - COMPENDIUM DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    RUCKER DF; MYERS DA

    2011-10-04

    This report documents the evolution of the surface geophysical exploration (SGE) program and highlights some of the most recent successes in imaging conductive targets related to past leaks within and around Hanford's tank farms. While it is noted that the SGE program consists of multiple geophysical techniques designed to (1) locate near surface infrastructure that may interfere with (2) subsurface plume mapping, the report will focus primarily on electrical resistivity acquisition and processing for plume mapping. Due to the interferences from the near surface piping network, tanks, fences, wells, etc., the results of the three-dimensional (3D) reconstruction of electrical resistivity was more representative of metal than the high ionic strength plumes. Since the first deployment, the focus of the SGE program has been to acquire and model the best electrical resistivity data that minimizes the influence of buried metal objects. Toward that goal, two significant advances have occurred: (1) using the infrastructure directly in the acquisition campaign and (2) placement of electrodes beneath the infrastructure. The direct use of infrastructure was successfully demonstrated at T farm by using wells as long electrodes (Rucker et al., 2010, 'Electrical-Resistivity Characterization of an Industrial Site Using Long Electrodes'). While the method was capable of finding targets related to past releases, a loss of vertical resolution was the trade-off. The burying of electrodes below the infrastructure helped to increase the vertical resolution, as long as a sufficient number of electrodes are available for the acquisition campaign.

  12. Inverse problems of geophysics

    International Nuclear Information System (INIS)

    Yanovskaya, T.B.

    2003-07-01

    This report gives an overview and the mathematical formulation of geophysical inverse problems. General principles of statistical estimation are explained. The maximum likelihood and least square fit methods, the Backus-Gilbert method and general approaches for solving inverse problems are discussed. General formulations of linearized inverse problems, singular value decomposition and properties of pseudo-inverse solutions are given

  13. Anisotropic conductivity imaging with MREIT using equipotential projection algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Degirmenci, Evren [Department of Electrical and Electronics Engineering, Mersin University, Mersin (Turkey); Eyueboglu, B Murat [Department of Electrical and Electronics Engineering, Middle East Technical University, 06531, Ankara (Turkey)

    2007-12-21

    Magnetic resonance electrical impedance tomography (MREIT) combines magnetic flux or current density measurements obtained by magnetic resonance imaging (MRI) and surface potential measurements to reconstruct images of true conductivity with high spatial resolution. Most of the biological tissues have anisotropic conductivity; therefore, anisotropy should be taken into account in conductivity image reconstruction. Almost all of the MREIT reconstruction algorithms proposed to date assume isotropic conductivity distribution. In this study, a novel MREIT image reconstruction algorithm is proposed to image anisotropic conductivity. Relative anisotropic conductivity values are reconstructed iteratively, using only current density measurements without any potential measurement. In order to obtain true conductivity values, only either one potential or conductivity measurement is sufficient to determine a scaling factor. The proposed technique is evaluated on simulated data for isotropic and anisotropic conductivity distributions, with and without measurement noise. Simulation results show that the images of both anisotropic and isotropic conductivity distributions can be reconstructed successfully.

  14. Intelligent and interactive computer image of a nuclear power plant: The ImagIn project

    International Nuclear Information System (INIS)

    Haubensack, D.; Malvache, P.; Valleix, P.

    1998-01-01

    The ImagIn project consists in a method and a set of computer tools apt to bring perceptible and assessable improvements in the operational safety of a nuclear plant. Its aim is to design an information system that would maintain a highly detailed computerized representation of a nuclear plant in its initial state and throughout its in-service life. It is not a tool to drive or help driving the nuclear plant, but a tool that manages concurrent operations that modify the plant configuration in a very general was (maintenance for example). The configuration of the plant, as well as rules and constraints about it, are described in a object-oriented knowledge database, which is built using a generic ImagIn meta-model based on the semantical network theory. An inference engine works on this database and is connected to reality through interfaces to operators and captors on the installation; it verifies constantly in real-time the consistency of the database according to its inner rules, and reports eventual problems to concerned operators. A special effort is made on interfaces to provide natural and intuitive tools (using virtual reality, natural language, voice recognition and synthesis). A laboratory application on a fictive but realistic installation already exists and is used to simulate various tests and scenarii. A real application is being constructed on Siloe, an experimental reactor of the CEA. (author)

  15. Adaptive fringe-pattern projection for image saturation avoidance in 3D surface-shape measurement.

    Science.gov (United States)

    Li, Dong; Kofman, Jonathan

    2014-04-21

    In fringe-projection 3D surface-shape measurement, image saturation results in incorrect intensities in captured images of fringe patterns, leading to phase and measurement errors. An adaptive fringe-pattern projection (AFPP) method was developed to adapt the maximum input gray level in projected fringe patterns to the local reflectivity of an object surface being measured. The AFPP method demonstrated improved 3D measurement accuracy by avoiding image saturation in highly-reflective surface regions while maintaining high intensity modulation across the entire surface. The AFPP method can avoid image saturation and handle varying surface reflectivity, using only two prior rounds of fringe-pattern projection and image capture to generate the adapted fringe patterns.

  16. Kernel based subspace projection of near infrared hyperspectral images of maize kernels

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Arngren, Morten; Hansen, Per Waaben

    2009-01-01

    In this paper we present an exploratory analysis of hyper- spectral 900-1700 nm images of maize kernels. The imaging device is a line scanning hyper spectral camera using a broadband NIR illumi- nation. In order to explore the hyperspectral data we compare a series of subspace projection methods ......- tor transform outperform the linear methods as well as kernel principal components in producing interesting projections of the data.......In this paper we present an exploratory analysis of hyper- spectral 900-1700 nm images of maize kernels. The imaging device is a line scanning hyper spectral camera using a broadband NIR illumi- nation. In order to explore the hyperspectral data we compare a series of subspace projection methods...... including principal component analysis and maximum autocorrelation factor analysis. The latter utilizes the fact that interesting phenomena in images exhibit spatial autocorrelation. However, linear projections often fail to grasp the underlying variability on the data. Therefore we propose to use so...

  17. Joint inversion of geophysical data for site characterization and restoration monitoring. FY97 annual progress report for EMSP

    International Nuclear Information System (INIS)

    Berge, P.A.; Berryman, J.G.; Bonner, B.P.; Roberts, J.J.; Wildenschild

    1997-01-01

    'The purpose of this project is to develop a computer code for joint in-version of seismic and electrical data, to improve underground imaging for site characterization and remediation monitoring. The computer code developed in this project will invert geophysical data to obtain direct estimates of porosity and saturation underground, rather than inverting for seismic velocity and electrical resistivity or other geophysical properties. This is intended to be a significant improvement in the state-of-the-art of under-ground imaging, since interpretation of data collected at a contaminated site would become much less subjective. The schedule of this project is as follows: In the first year, investigators perform laboratory measurements of elastic and electrical properties of sand-clay mixtures containing various fluids. Investigators also develop methods of relating measurable geophysical properties to porosity and saturation by using rock physics theories, geostatistical, and empirical techniques together with available laboratory measurements. In the second year, investigators finish any necessary laboratory measurements and apply the methods developed in the first year to invert available borehole log data to predict measured properties of cores and sediments from a borehole. Investigators refine the inversion code in the third year and carry out a field experiment to collect seismic and electrical data. Investigators then use the inversion code to invert the field data to produce estimates of porosity and saturation in the field area where the data were collected. This report describes progress made in the first year of this three-year project.'

  18. Accelerated Optical Projection Tomography Applied to In Vivo Imaging of Zebrafish.

    Directory of Open Access Journals (Sweden)

    Teresa Correia

    Full Text Available Optical projection tomography (OPT provides a non-invasive 3-D imaging modality that can be applied to longitudinal studies of live disease models, including in zebrafish. Current limitations include the requirement of a minimum number of angular projections for reconstruction of reasonable OPT images using filtered back projection (FBP, which is typically several hundred, leading to acquisition times of several minutes. It is highly desirable to decrease the number of required angular projections to decrease both the total acquisition time and the light dose to the sample. This is particularly important to enable longitudinal studies, which involve measurements of the same fish at different time points. In this work, we demonstrate that the use of an iterative algorithm to reconstruct sparsely sampled OPT data sets can provide useful 3-D images with 50 or fewer projections, thereby significantly decreasing the minimum acquisition time and light dose while maintaining image quality. A transgenic zebrafish embryo with fluorescent labelling of the vasculature was imaged to acquire densely sampled (800 projections and under-sampled data sets of transmitted and fluorescence projection images. The under-sampled OPT data sets were reconstructed using an iterative total variation-based image reconstruction algorithm and compared against FBP reconstructions of the densely sampled data sets. To illustrate the potential for quantitative analysis following rapid OPT data acquisition, a Hessian-based method was applied to automatically segment the reconstructed images to select the vasculature network. Results showed that 3-D images of the zebrafish embryo and its vasculature of sufficient visual quality for quantitative analysis can be reconstructed using the iterative algorithm from only 32 projections-achieving up to 28 times improvement in imaging speed and leading to total acquisition times of a few seconds.

  19. Fluorescence guided lymph node biopsy in large animals using direct image projection device

    Science.gov (United States)

    Ringhausen, Elizabeth; Wang, Tylon; Pitts, Jonathan; Akers, Walter J.

    2016-03-01

    The use of fluorescence imaging for aiding oncologic surgery is a fast growing field in biomedical imaging, revolutionizing open and minimally invasive surgery practices. We have designed, constructed, and tested a system for fluorescence image acquisition and direct display on the surgical field for fluorescence guided surgery. The system uses a near-infrared sensitive CMOS camera for image acquisition, a near-infra LED light source for excitation, and DLP digital projector for projection of fluorescence image data onto the operating field in real time. Instrument control was implemented in Matlab for image capture, processing of acquired data and alignment of image parameters with the projected pattern. Accuracy of alignment was evaluated statistically to demonstrate sensitivity to small objects and alignment throughout the imaging field. After verification of accurate alignment, feasibility for clinical application was demonstrated in large animal models of sentinel lymph node biopsy. Indocyanine green was injected subcutaneously in Yorkshire pigs at various locations to model sentinel lymph node biopsy in gynecologic cancers, head and neck cancer, and melanoma. Fluorescence was detected by the camera system during operations and projected onto the imaging field, accurately identifying tissues containing the fluorescent tracer at up to 15 frames per second. Fluorescence information was projected as binary green regions after thresholding and denoising raw intensity data. Promising results with this initial clinical scale prototype provided encouraging results for the feasibility of optical projection of acquired luminescence during open oncologic surgeries.

  20. Optimized image acquisition for breast tomosynthesis in projection and reconstruction space

    International Nuclear Information System (INIS)

    Chawla, Amarpreet S.; Lo, Joseph Y.; Baker, Jay A.; Samei, Ehsan

    2009-01-01

    Breast tomosynthesis has been an exciting new development in the field of breast imaging. While the diagnostic improvement via tomosynthesis is notable, the full potential of tomosynthesis has not yet been realized. This may be attributed to the dependency of the diagnostic quality of tomosynthesis on multiple variables, each of which needs to be optimized. Those include dose, number of angular projections, and the total angular span of those projections. In this study, the authors investigated the effects of these acquisition parameters on the overall diagnostic image quality of breast tomosynthesis in both the projection and reconstruction space. Five mastectomy specimens were imaged using a prototype tomosynthesis system. 25 angular projections of each specimen were acquired at 6.2 times typical single-view clinical dose level. Images at lower dose levels were then simulated using a noise modification routine. Each projection image was supplemented with 84 simulated 3 mm 3D lesions embedded at the center of 84 nonoverlapping ROIs. The projection images were then reconstructed using a filtered backprojection algorithm at different combinations of acquisition parameters to investigate which of the many possible combinations maximizes the performance. Performance was evaluated in terms of a Laguerre-Gauss channelized Hotelling observer model-based measure of lesion detectability. The analysis was also performed without reconstruction by combining the model results from projection images using Bayesian decision fusion algorithm. The effect of acquisition parameters on projection images and reconstructed slices were then compared to derive an optimization rule for tomosynthesis. The results indicated that projection images yield comparable but higher performance than reconstructed images. Both modes, however, offered similar trends: Performance improved with an increase in the total acquisition dose level and the angular span. Using a constant dose level and angular

  1. Geophysical drillhole logging and imaging of drillholes OL-KR51, OL-KR52, OL-KR52B, OL-KR53 and OL-KR53B at Olkiluoto in 2009 and 2010

    International Nuclear Information System (INIS)

    Tarvainen, A.-M.

    2010-10-01

    Suomen Malmi Oy conducted geophysical drillhole logging and optical imaging of the drillholes OL-KR51, OL-KR52, OL-KR52B, OL-KR53 and OL-KR53B at the Olkiluoto site in Eurajoki between November 2009 and February 2010. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  2. Pre-analytic process control: projecting a quality image.

    Science.gov (United States)

    Serafin, Mark D

    2006-09-26

    Within the health-care system, the term "ancillary department" often describes the laboratory. Thus, laboratories may find it difficult to define their image and with it, customer perception of department quality. Regulatory requirements give laboratories who so desire an elegant way to address image and perception issues--a comprehensive pre-analytic system solution. Since large laboratories use such systems--laboratory service manuals--I describe and illustrate the process for the benefit of smaller facilities. There exist resources to help even small laboratories produce a professional service manual--an elegant solution to image and customer perception of quality.

  3. Recent advances and future projections in clinical radionuclide imaging

    International Nuclear Information System (INIS)

    Peters, A.M.

    1990-01-01

    This outline review of recent advances in radionuclide imaging draws attention to developments in nuclear medicine of the urinary tract such as Captopril renography and the introduction of MAG-3, the technetium-99m labelled mimic of hippuran, the use of radionuclides for infection diagnosis, advances in lung perfusion scanning, new radiopharmaceuticals for cardiac imaging, and developments in radiopharmaceuticals for imaging tumours, including gallium-67, thallium-201, and the development of radiolabelled monoclonal antibodies. Attention is drawn to the wider use of nuclear medicine in child care. (author)

  4. Fundamentals of Geophysics

    Science.gov (United States)

    Frohlich, Cliff

    Choosing an intermediate-level geophysics text is always problematic: What should we teach students after they have had introductory courses in geology, math, and physics, but little else? Fundamentals of Geophysics is aimed specifically at these intermediate-level students, and the author's stated approach is to construct a text “using abundant diagrams, a simplified mathematical treatment, and equations in which the student can follow each derivation step-by-step.” Moreover, for Lowrie, the Earth is round, not flat—the “fundamentals of geophysics” here are the essential properties of our Earth the planet, rather than useful techniques for finding oil and minerals. Thus this book is comparable in both level and approach to C. M. R. Fowler's The Solid Earth (Cambridge University Press, 1990).

  5. Geophysical investigations in Jordan

    Science.gov (United States)

    Kovach, R.L.; Andreasen, G.E.; Gettings, M.E.; El-Kaysi, K.

    1990-01-01

    A number of geophysical investigations have been undertaken in the Hashemite Kingdom of Jordan to provide data for understanding the tectonic framework, the pattern of seismicity, earthquake hazards and geothermal resources of the country. Both the historical seismic record and the observed recent seismicity point to the dominance of the Dead Sea Rift as the main locus of seismic activity but significant branching trends and gaps in the seismicity pattern are also seen. A wide variety of focal plane solutions are observed emphasizing the complex pattern of fault activity in the vicinity of the rift zone. Geophysical investigations directed towards the geothermal assessment of the prominent thermal springs of Zerga Ma'in and Zara are not supportive of the presence of a crustal magmatic source. ?? 1990.

  6. Rapid Acquisition Imaging Spectrograph (RAISE) Renewal Proposal Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The optical design of RAISE is based on a new class of UV/EUV imaging spectrometers that use  only two reflections to provide quasi-stigmatic performance...

  7. Sparse Nonlinear Electromagnetic Imaging Accelerated With Projected Steepest Descent Algorithm

    KAUST Repository

    Desmal, Abdulla; Bagci, Hakan

    2017-01-01

    steepest descent algorithm. The algorithm uses a projection operator to enforce the sparsity constraint by thresholding the solution at every iteration. Thresholding level and iteration step are selected carefully to increase the efficiency without

  8. Geophysics: Building E5476 decommissiong, Aberdeen Proving Ground

    International Nuclear Information System (INIS)

    Miller, S.F.; Thompson, M.D.; McGinnis, M.G.; McGinnis, L.D.

    1992-11-01

    Building E5476 was one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar, were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The large number of magnetic sources surrounding the building are believed to be contained in construction fill. The smaller anomalies, for the most part, were not imaged with ground radar or by electrical profiling. Large magnetic anomalies near the southwest comer of the building are due to aboveground standpipes and steel-reinforced concrete. Two high-resistivity areas, one projecting northeast from the building and another south of the original structure, may indicate the presence of organic pore fluids in the subsurface. A conductive lineament protruding from the south wall that is enclosed by the southem, high-resistivity feature is not associated with an equivalent magnetic anomaly. Magnetic and electrical anomalies south of the old landfill boundary are probably not associated with the building. The boundary is marked by a band of magnetic anomalies and a conductive zone trending northwest to southeast. The cause of high resistivities in a semicircular area in the southwest comer, within the landfill area, is unexplained

  9. Digital projection radiography. Technical principles, image properties and potential applications

    International Nuclear Information System (INIS)

    Busch, H.P.

    1999-01-01

    The history of development of digital projection radiography as a diagnostic method is presented in a comprehensive survey. The various technical principles are explained in detail and illustrated by means of graphic figures and digital X-ray pictures. A comparative assessment of currently applied radiographic systems is given and the potential clinical applications of the method of digital projection radiography are discussed. (orig./CB) [de

  10. THE IMAGE REGISTRATION OF FOURIER-MELLIN BASED ON THE COMBINATION OF PROJECTION AND GRADIENT PREPROCESSING

    Directory of Open Access Journals (Sweden)

    D. Gao

    2017-09-01

    Full Text Available Image registration is one of the most important applications in the field of image processing. The method of Fourier Merlin transform, which has the advantages of high precision and good robustness to change in light and shade, partial blocking, noise influence and so on, is widely used. However, not only this method can’t obtain the unique mutual power pulse function for non-parallel image pairs, even part of image pairs also can’t get the mutual power function pulse. In this paper, an image registration method based on Fourier-Mellin transformation in the view of projection-gradient preprocessing is proposed. According to the projection conformational equation, the method calculates the matrix of image projection transformation to correct the tilt image; then, gradient preprocessing and Fourier-Mellin transformation are performed on the corrected image to obtain the registration parameters. Eventually, the experiment results show that the method makes the image registration of Fourier-Mellin transformation not only applicable to the registration of the parallel image pairs, but also to the registration of non-parallel image pairs. What’s more, the better registration effect can be obtained

  11. 3-D Velocity Model of the Coachella Valley, Southern California Based on Explosive Shots from the Salton Seismic Imaging Project

    Science.gov (United States)

    Persaud, P.; Stock, J. M.; Fuis, G. S.; Hole, J. A.; Goldman, M.; Scheirer, D. S.

    2014-12-01

    We have analyzed explosive shot data from the 2011 Salton Seismic Imaging Project (SSIP) across a 2-D seismic array and 5 profiles in the Coachella Valley to produce a 3-D P-wave velocity model that will be used in calculations of strong ground shaking. Accurate maps of seismicity and active faults rely both on detailed geological field mapping and a suitable velocity model to accurately locate earthquakes. Adjoint tomography of an older version of the SCEC 3-D velocity model shows that crustal heterogeneities strongly influence seismic wave propagation from moderate earthquakes (Tape et al., 2010). These authors improve the crustal model and subsequently simulate the details of ground motion at periods of 2 s and longer for hundreds of ray paths. Even with improvements such as the above, the current SCEC velocity model for the Salton Trough does not provide a match of the timing or waveforms of the horizontal S-wave motions, which Wei et al. (2013) interpret as caused by inaccuracies in the shallow velocity structure. They effectively demonstrate that the inclusion of shallow basin structure improves the fit in both travel times and waveforms. Our velocity model benefits from the inclusion of known location and times of a subset of 126 shots detonated over a 3-week period during the SSIP. This results in an improved velocity model particularly in the shallow crust. In addition, one of the main challenges in developing 3-D velocity models is an uneven stations-source distribution. To better overcome this challenge, we also include the first arrival times of the SSIP shots at the more widely spaced Southern California Seismic Network (SCSN) in our inversion, since the layout of the SSIP is complementary to the SCSN. References: Tape, C., et al., 2010, Seismic tomography of the Southern California crust based on spectral-element and adjoint methods: Geophysical Journal International, v. 180, no. 1, p. 433-462. Wei, S., et al., 2013, Complementary slip distributions

  12. Dynamic Underground Stripping Project

    International Nuclear Information System (INIS)

    Aines, R.; Newmark, R.; McConachie, W.; Udell, K.; Rice, D.; Ramirez, A.; Siegel, W.; Buettner, M.; Daily, W.; Krauter, P.; Folsom, E.; Boegel, A.J.; Bishop, D.; Udell, K.

    1992-01-01

    LLNL is collaborating with the UC Berkeley College of Engineering to develop and demonstrate a system of thermal remediation and underground imaging techniques for use in rapid cleanup of localized underground spills. Called ''Dynamic Stripping'' to reflect the rapid and controllable nature of the process, it will combine steam injection, direct electrical heating, and tomographic geophysical imaging in a cleanup of the LLNL gasoline spill. In the first 8 months of the project, a Clean Site engineering test was conducted to prove the field application of the techniques before moving the contaminated site in FY 92

  13. Rapid Geophysical Surveyor

    International Nuclear Information System (INIS)

    Roybal, L.G.; Carpenter, G.S.; Josten, N.E.

    1993-01-01

    The Rapid Geophysical Surveyor (RGS) is a system designed to rapidly and economically collect closely-spaced geophysical data used for characterization of US Department of Energy waste sites. Geophysical surveys of waste sites are an important first step in the remediation and closure of these sites; especially older sites where historical records are inaccurate and survey benchmarks have changed because of refinements in coordinate controls and datum changes. Closely-spaced data are required to adequately differentiate pits, trenches, and soil vault rows whose edges may be only a few feet from each other. A prototype vehicle designed to collect magnetic field data was built at the Idaho National Engineering Laboratory (INEL) during the summer of 1992. The RGS was funded by the Buried Waste Integrated Demonstration program. This vehicle was demonstrated at the Subsurface Disposal Area (SDA) within the Radioactive Waste Management Complex at the INEL in September 1992. Magnetic data were collected over two areas in the SDA, with a total survey area of about 1.7 acres. Data were collected at a nominal density of 2 1/2 in. along survey lines spaced 1-ft apart. Over 350,000 data points were collected over a 6 day period corresponding to about 185 worker-days using conventional ground survey techniques

  14. Correction of projective distortion in long-image-sequence mosaics without prior information

    Science.gov (United States)

    Yang, Chenhui; Mao, Hongwei; Abousleman, Glen; Si, Jennie

    2010-04-01

    Image mosaicking is the process of piecing together multiple video frames or still images from a moving camera to form a wide-area or panoramic view of the scene being imaged. Mosaics have widespread applications in many areas such as security surveillance, remote sensing, geographical exploration, agricultural field surveillance, virtual reality, digital video, and medical image analysis, among others. When mosaicking a large number of still images or video frames, the quality of the resulting mosaic is compromised by projective distortion. That is, during the mosaicking process, the image frames that are transformed and pasted to the mosaic become significantly scaled down and appear out of proportion with respect to the mosaic. As more frames continue to be transformed, important target information in the frames can be lost since the transformed frames become too small, which eventually leads to the inability to continue further. Some projective distortion correction techniques make use of prior information such as GPS information embedded within the image, or camera internal and external parameters. Alternatively, this paper proposes a new algorithm to reduce the projective distortion without using any prior information whatsoever. Based on the analysis of the projective distortion, we approximate the projective matrix that describes the transformation between image frames using an affine model. Using singular value decomposition, we can deduce the affine model scaling factor that is usually very close to 1. By resetting the image scale of the affine model to 1, the transformed image size remains unchanged. Even though the proposed correction introduces some error in the image matching, this error is typically acceptable and more importantly, the final mosaic preserves the original image size after transformation. We demonstrate the effectiveness of this new correction algorithm on two real-world unmanned air vehicle (UAV) sequences. The proposed method is

  15. The Multidimensional Integrated Intelligent Imaging project (MI-3)

    International Nuclear Information System (INIS)

    Allinson, N.; Anaxagoras, T.; Aveyard, J.; Arvanitis, C.; Bates, R.; Blue, A.; Bohndiek, S.; Cabello, J.; Chen, L.; Chen, S.; Clark, A.; Clayton, C.; Cook, E.; Cossins, A.; Crooks, J.; El-Gomati, M.; Evans, P.M.; Faruqi, W.; French, M.; Gow, J.

    2009-01-01

    MI-3 is a consortium of 11 universities and research laboratories whose mission is to develop complementary metal-oxide semiconductor (CMOS) active pixel sensors (APS) and to apply these sensors to a range of imaging challenges. A range of sensors has been developed: On-Pixel Intelligent CMOS (OPIC)-designed for in-pixel intelligence; FPN-designed to develop novel techniques for reducing fixed pattern noise; HDR-designed to develop novel techniques for increasing dynamic range; Vanilla/PEAPS-with digital and analogue modes and regions of interest, which has also been back-thinned; Large Area Sensor (LAS)-a novel, stitched LAS; and eLeNA-which develops a range of low noise pixels. Applications being developed include autoradiography, a gamma camera system, radiotherapy verification, tissue diffraction imaging, X-ray phase-contrast imaging, DNA sequencing and electron microscopy.

  16. The Multidimensional Integrated Intelligent Imaging project (MI-3)

    Energy Technology Data Exchange (ETDEWEB)

    Allinson, N.; Anaxagoras, T. [Vision and Information Engineering, University of Sheffield (United Kingdom); Aveyard, J. [Laboratory for Environmental Gene Regulation, University of Liverpool (United Kingdom); Arvanitis, C. [Radiation Physics, University College, London (United Kingdom); Bates, R.; Blue, A. [Experimental Particle Physics, University of Glasgow (United Kingdom); Bohndiek, S. [Radiation Physics, University College, London (United Kingdom); Cabello, J. [Centre for Vision, Speech and Signal Processing, University of Surrey, Guildford (United Kingdom); Chen, L. [Electron Optics, Applied Electromagnetics and Electron Optics, University of York (United Kingdom); Chen, S. [MRC Laboratory for Molecular Biology, Cambridge (United Kingdom); Clark, A. [STFC Rutherford Appleton Laboratories (United Kingdom); Clayton, C. [Vision and Information Engineering, University of Sheffield (United Kingdom); Cook, E. [Radiation Physics, University College, London (United Kingdom); Cossins, A. [Laboratory for Environmental Gene Regulation, University of Liverpool (United Kingdom); Crooks, J. [STFC Rutherford Appleton Laboratories (United Kingdom); El-Gomati, M. [Electron Optics, Applied Electromagnetics and Electron Optics, University of York (United Kingdom); Evans, P.M. [Institute of Cancer Research, Sutton, Surrey SM2 5PT (United Kingdom)], E-mail: phil.evans@icr.ac.uk; Faruqi, W. [MRC Laboratory for Molecular Biology, Cambridge (United Kingdom); French, M. [STFC Rutherford Appleton Laboratories (United Kingdom); Gow, J. [Imaging for Space and Terrestrial Applications, Brunel University, London (United Kingdom)] (and others)

    2009-06-01

    MI-3 is a consortium of 11 universities and research laboratories whose mission is to develop complementary metal-oxide semiconductor (CMOS) active pixel sensors (APS) and to apply these sensors to a range of imaging challenges. A range of sensors has been developed: On-Pixel Intelligent CMOS (OPIC)-designed for in-pixel intelligence; FPN-designed to develop novel techniques for reducing fixed pattern noise; HDR-designed to develop novel techniques for increasing dynamic range; Vanilla/PEAPS-with digital and analogue modes and regions of interest, which has also been back-thinned; Large Area Sensor (LAS)-a novel, stitched LAS; and eLeNA-which develops a range of low noise pixels. Applications being developed include autoradiography, a gamma camera system, radiotherapy verification, tissue diffraction imaging, X-ray phase-contrast imaging, DNA sequencing and electron microscopy.

  17. Multi-example feature-constrained back-projection method for image super-resolution

    Institute of Scientific and Technical Information of China (English)

    Junlei Zhang; Dianguang Gai; Xin Zhang; Xuemei Li

    2017-01-01

    Example-based super-resolution algorithms,which predict unknown high-resolution image information using a relationship model learnt from known high- and low-resolution image pairs, have attracted considerable interest in the field of image processing. In this paper, we propose a multi-example feature-constrained back-projection method for image super-resolution. Firstly, we take advantage of a feature-constrained polynomial interpolation method to enlarge the low-resolution image. Next, we consider low-frequency images of different resolutions to provide an example pair. Then, we use adaptive k NN search to find similar patches in the low-resolution image for every image patch in the high-resolution low-frequency image, leading to a regression model between similar patches to be learnt. The learnt model is applied to the low-resolution high-frequency image to produce high-resolution high-frequency information. An iterative back-projection algorithm is used as the final step to determine the final high-resolution image.Experimental results demonstrate that our method improves the visual quality of the high-resolution image.

  18. Integrated geophysical-geochemical methods for archaeological prospecting

    OpenAIRE

    Persson, Kjell

    2005-01-01

    A great number of field measurements with different methods and instruments were conducted in attempts to develop a method for an optimal combination of various geochemical and geophysical methods in archaeological prospecting. The research presented in this thesis focuses on a study of how different anthropogenic changes in the ground can be detected by geochemical and geophysical mapping and how the results can be presented. A six-year pilot project, Svealand in Vendel and Viking periods (S...

  19. A multi-method high-resolution geophysical survey in the Machado de Castro museum, central Portugal

    International Nuclear Information System (INIS)

    Grangeia, Carlos; Matias, Manuel; Hermozilha, Hélder; Figueiredo, Fernando; Carvalho, Pedro; Silva, Ricardo

    2011-01-01

    Restoration of historical buildings is a delicate operation as they are often built over more ancient and important structures. The Machado de Castro Museum, Coimbra, Central Portugal, has suffered several interventions in historical times and lies over the ancient Roman forum of Coimbra. This building went through a restoration project. These works were preceded by an extensive geophysical survey that aimed at investigating subsurface stratigraphy, including archeological remains, and the internal structure of the actual walls. Owing to the needs of the project, geophysical data interpretation required not only integration but also high resolution. The study consisted of data acquisition over perpendicular planes and different levels that required detailed survey planning and integration of data from different locations that complement images of the surveyed area. Therefore a multi-method, resistivity imaging and a 3D ground probing radar (GPR), high-resolution geophysical survey was done inside the museum. Herein, radargrams are compared with the revealed stratigraphy so that signatures are interpreted, characterized and assigned to archeological structures. Although resistivity and GPR have different resolution capabilities, their data are overlapped and compared, bearing in mind the specific characteristics of this survey. It was also possible to unravel the inner structure of the actual walls, to establish connections between walls, foundations and to find older remains with the combined use and spatial integration of the GPR and resistivity imaging data

  20. Research interface for experimental ultrasound imaging - the CFU grabber project

    DEFF Research Database (Denmark)

    Pedersen, Mads Møller; Hemmsen, Martin Christian; Jensen, Jørgen Arendt

    system RASMUS. Furthermore precise scanner settings are stored for inter- and intra-observer studies. The resulting images are used for clinical evaluation. Method and materials The ultrasound scanners research interface is connected to a graphical grabber card in a Windows PC (Grabber PC). The grabber...

  1. Image restoration by the method of convex projections: part 2 applications and numerical results.

    Science.gov (United States)

    Sezan, M I; Stark, H

    1982-01-01

    The image restoration theory discussed in a previous paper by Youla and Webb [1] is applied to a simulated image and the results compared with the well-known method known as the Gerchberg-Papoulis algorithm. The results show that the method of image restoration by projection onto convex sets, by providing a convenient technique for utilizing a priori information, performs significantly better than the Gerchberg-Papoulis method.

  2. Joint Inversion Modelling of Geophysical Data From Lough Neagh Basin

    Science.gov (United States)

    Vozar, J.; Moorkamp, M.; Jones, A. G.; Rath, V.; Muller, M. R.

    2015-12-01

    Multi-dimensional modelling of geophysical data collected in the Lough Neagh Basin is presented in the frame of the IRETHERM project. The Permo-Triassic Lough Neagh Basin, situated in the southeastern part of Northern Ireland, exhibits elevated geothermal gradient (~30 °C/km) in the exploratory drilled boreholes. This is taken to indicate good geothermal exploitation potential in the Sherwood Sandstone aquifer for heating, and possibly even electricity production, purposes. We have used a 3-D joint inversion framework for modelling the magnetotelluric (MT) and gravity data collected to the north of the Lough Neagh to derive robust subsurface geological models. Comprehensive supporting geophysical and geological data (e.g. borehole logs and reflection seismic images) have been used in order to analyze and model the MT and gravity data. The geophysical data sets were provided by the Geological Survey of Northern Ireland (GSNI). Considering correct objective function weighting in favor of noise-free MT response functions is particularly important in joint inversion. There is no simple way how to correct distortion effects the 3-D responses as can be done in 1-D or 2-D case. We have used the Tellus Project airborne EM data to constrain magnetotelluric data and correct them for near surface effects. The shallow models from airborne data are used to constrain the uppermost part of 3-D inversion model. Preliminary 3-D joint inversion modeling reveals that the Sherwood Sandstone Group and the Permian Sandstone Formation are imaged as a conductive zone at the depth range of 500 m to 2000 m with laterally varying thickness, depth, and conductance. The conductive target sediments become shallower and thinner to the north and they are laterally continuous. To obtain better characterization of thermal transport properties of investigated area we used porosity and resistivity data from the Annaghmore and Ballymacilroy boreholes to estimate the relations between porosity

  3. Evaluation of noise limits to improve image processing in soft X-ray projection microscopy.

    Science.gov (United States)

    Jamsranjav, Erdenetogtokh; Kuge, Kenichi; Ito, Atsushi; Kinjo, Yasuhito; Shiina, Tatsuo

    2017-03-03

    Soft X-ray microscopy has been developed for high resolution imaging of hydrated biological specimens due to the availability of water window region. In particular, a projection type microscopy has advantages in wide viewing area, easy zooming function and easy extensibility to computed tomography (CT). The blur of projection image due to the Fresnel diffraction of X-rays, which eventually reduces spatial resolution, could be corrected by an iteration procedure, i.e., repetition of Fresnel and inverse Fresnel transformations. However, it was found that the correction is not enough to be effective for all images, especially for images with low contrast. In order to improve the effectiveness of image correction by computer processing, we in this study evaluated the influence of background noise in the iteration procedure through a simulation study. In the study, images of model specimen with known morphology were used as a substitute for the chromosome images, one of the targets of our microscope. Under the condition that artificial noise was distributed on the images randomly, we introduced two different parameters to evaluate noise effects according to each situation where the iteration procedure was not successful, and proposed an upper limit of the noise within which the effective iteration procedure for the chromosome images was possible. The study indicated that applying the new simulation and noise evaluation method was useful for image processing where background noises cannot be ignored compared with specimen images.

  4. Quantitative estimation of brain atrophy and function with PET and MRI two-dimensional projection images

    International Nuclear Information System (INIS)

    Saito, Reiko; Uemura, Koji; Uchiyama, Akihiko; Toyama, Hinako; Ishii, Kenji; Senda, Michio

    2001-01-01

    The purpose of this paper is to estimate the extent of atrophy and the decline in brain function objectively and quantitatively. Two-dimensional (2D) projection images of three-dimensional (3D) transaxial images of positron emission tomography (PET) and magnetic resonance imaging (MRI) were made by means of the Mollweide method which keeps the area of the brain surface. A correlation image was generated between 2D projection images of MRI and cerebral blood flow (CBF) or 18 F-fluorodeoxyglucose (FDG) PET images and the sulcus was extracted from the correlation image clustered by K-means method. Furthermore, the extent of atrophy was evaluated from the extracted sulcus on 2D-projection MRI and the cerebral cortical function such as blood flow or glucose metabolic rate was assessed in the cortex excluding sulcus on 2D-projection PET image, and then the relationship between the cerebral atrophy and function was evaluated. This method was applied to the two groups, the young and the aged normal subjects, and the relationship between the age and the rate of atrophy or the cerebral blood flow was investigated. This method was also applied to FDG-PET and MRI studies in the normal controls and in patients with corticobasal degeneration. The mean rate of atrophy in the aged group was found to be higher than that in the young. The mean value and the variance of the cerebral blood flow for the young are greater than those of the aged. The sulci were similarly extracted using either CBF or FDG PET images. The purposed method using 2-D projection images of MRI and PET is clinically useful for quantitative assessment of atrophic change and functional disorder of cerebral cortex. (author)

  5. A projection graphic display for the computer aided analysis of bubble chamber images

    International Nuclear Information System (INIS)

    Solomos, E.

    1979-01-01

    A projection graphic display for aiding the analysis of bubble chamber photographs has been developed by the Instrumentation Group of EF Division at CERN. The display image is generated on a very high brightness cathode ray tube and projected on to the table of the scanning-measuring machines as a superposition to the image of the bubble chamber. The display can send messages to the operator and aid the measurement by indicating directly on the chamber image the tracks which are measured correctly or not. (orig.)

  6. Geophysical considerations of geothermics

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, M

    1967-01-01

    The development and utilization of geothermal energy is described from the standpoint of geophysics. The internal temperature of the Earth and the history and composition of magmas are described. Methods of exploration such as gravity, magnetic, thermal and electrical surveys are discussed, as are geochemical and infrared photogrammetric techniques. Examples are provided of how these techniques have been used in Italy and at the Matsukawa geothermal field in Japan. Drilling considerations such as muds, casings and cementing materials are discussed. Solutions are proposed for problems of environmental pollution and plant expansion.

  7. Geophysical monitoring in a hydrocarbon reservoir

    Science.gov (United States)

    Caffagni, Enrico; Bokelmann, Goetz

    2016-04-01

    Extraction of hydrocarbons from reservoirs demands ever-increasing technological effort, and there is need for geophysical monitoring to better understand phenomena occurring within the reservoir. Significant deformation processes happen when man-made stimulation is performed, in combination with effects deriving from the existing natural conditions such as stress regime in situ or pre-existing fracturing. Keeping track of such changes in the reservoir is important, on one hand for improving recovery of hydrocarbons, and on the other hand to assure a safe and proper mode of operation. Monitoring becomes particularly important when hydraulic-fracturing (HF) is used, especially in the form of the much-discussed "fracking". HF is a sophisticated technique that is widely applied in low-porosity geological formations to enhance the production of natural hydrocarbons. In principle, similar HF techniques have been applied in Europe for a long time in conventional reservoirs, and they will probably be intensified in the near future; this suggests an increasing demand in technological development, also for updating and adapting the existing monitoring techniques in applied geophysics. We review currently available geophysical techniques for reservoir monitoring, which appear in the different fields of analysis in reservoirs. First, the properties of the hydrocarbon reservoir are identified; here we consider geophysical monitoring exclusively. The second step is to define the quantities that can be monitored, associated to the properties. We then describe the geophysical monitoring techniques including the oldest ones, namely those in practical usage from 40-50 years ago, and the most recent developments in technology, within distinct groups, according to the application field of analysis in reservoir. This work is performed as part of the FracRisk consortium (www.fracrisk.eu); this project, funded by the Horizon2020 research programme, aims at helping minimize the

  8. HMF-Geophysics - An Update

    Science.gov (United States)

    Crook, N.; Knight, R.; Robinson, D.

    2007-12-01

    There is growing recognition of the challenges we face, in many parts of the world, in finding and maintaining clean sources of water for human consumption and agricultural use, while balancing the needs of the natural world. Advancements in hydrologic sciences are needed in order to develop an improved understanding of the controls on the quantity, movement, and quality of water, thus enhancing our ability to better protect and manage our water resources. Geophysical methods can play a central role in these investigations. CUAHSI (Consortium of Universities for the Advancement of Hydrologic Sciences) is developing, with the support of the National Science Foundation, a Hydrologic Measurement Facility (HMF), which contains a Geophysics module, referred to as HMF-Geophysics. The Geophysics module will support and advance the use of geophysics for hydrologic applications. Currently in second year of a 3 year pilot study, the main aim of HMF-Geophysics is to develop the infrastructure necessary to provide geophysical techniques and the expertise to apply them correctly for the hydrological community. The current working model consists of a central HMF-Geophysics facility and a number of volunteer nodes. The latter consists of individuals at universities who have volunteered to be part of HMF-Geophysics by using their equipment, and/or software, and expertise, in research partnerships with hydrologists. In response to an inquiry the central facility takes on the evaluation of the potential of geophysics to the area of research/watershed. The central facility can then undertake a feasibility study to determine how/if geophysical methods could be of use, and to evaluate the "value-added" by geophysics to the science. Once it is clear that the geophysics can contribute in a significant way to addressing the science questions the central facility works with the hydrologist to set up the next step. Our assumption is that at this point, the hydrologist (perhaps with a

  9. A user-friendly, dynamic web environment for remote data browsing and analysis of multiparametric geophysical data within the MULTIMO project

    Science.gov (United States)

    Carniel, Roberto; Di Cecca, Mauro; Jaquet, Olivier

    2006-05-01

    In the framework of the EU-funded project "Multi-disciplinary monitoring, modelling and forecasting of volcanic hazard" (MULTIMO), multiparametric data have been recorded at the MULTIMO station in Montserrat. Moreover, several other long time series, recorded at Montserrat and at other volcanoes, have been acquired in order to test stochastic and deterministic methodologies under development. Creating a general framework to handle data efficiently is a considerable task even for homogeneous data. In the case of heterogeneous data, this becomes a major issue. A need for a consistent way of browsing such a heterogeneous dataset in a user-friendly way therefore arose. Additionally, a framework for applying the calculation of the developed dynamical parameters on the data series was also needed in order to easily keep these parameters under control, e.g. for monitoring, research or forecasting purposes. The solution which we present is completely based on Open Source software, including Linux operating system, MySql database management system, Apache web server, Zope application server, Scilab math engine, Plone content management framework, Unified Modelling Language. From the user point of view the main advantage is the possibility of browsing through datasets recorded on different volcanoes, with different instruments, with different sampling frequencies, stored in different formats, all via a consistent, user- friendly interface that transparently runs queries to the database, gets the data from the main storage units, generates the graphs and produces dynamically generated web pages to interact with the user. The involvement of third parties for continuing the development in the Open Source philosophy and/or extending the application fields is now sought.

  10. Design and Development of a New Multi-Projection X-Ray System for Chest Imaging

    Science.gov (United States)

    Chawla, Amarpreet S.; Boyce, Sarah; Washington, Lacey; McAdams, H. Page; Samei, Ehsan

    2009-02-01

    Overlapping anatomical structures may confound the detection of abnormal pathology, including lung nodules, in conventional single-projection chest radiography. To minimize this fundamental limiting factor, a dedicated digital multi-projection system for chest imaging was recently developed at the Radiology Department of Duke University. We are reporting the design of the multi-projection imaging system and its initial performance in an ongoing clinical trial. The system is capable of acquiring multiple full-field projections of the same patient along both the horizontal and vertical axes at variable speeds and acquisition frame rates. These images acquired in rapid succession from slightly different angles about the posterior-anterior (PA) orientation can be correlated to minimize the influence of overlying anatomy. The developed system has been tested for repeatability and motion blur artifacts to investigate its robustness for clinical trials. Excellent geometrical consistency was found in the tube motion, with positional errors for clinical settings within 1%. The effect of tube-motion on the image quality measured in terms of impact on the modulation transfer function (MTF) was found to be minimal. The system was deemed clinic-ready and a clinical trial was subsequently launched. The flexibility of image acquisition built into the system provides a unique opportunity to easily modify it for different clinical applications, including tomosynthesis, correlation imaging (CI), and stereoscopic imaging.

  11. Augmented reality-guided neurosurgery: accuracy and intraoperative application of an image projection technique.

    Science.gov (United States)

    Besharati Tabrizi, Leila; Mahvash, Mehran

    2015-07-01

    An augmented reality system has been developed for image-guided neurosurgery to project images with regions of interest onto the patient's head, skull, or brain surface in real time. The aim of this study was to evaluate system accuracy and to perform the first intraoperative application. Images of segmented brain tumors in different localizations and sizes were created in 10 cases and were projected to a head phantom using a video projector. Registration was performed using 5 fiducial markers. After each registration, the distance of the 5 fiducial markers from the visualized tumor borders was measured on the virtual image and on the phantom. The difference was considered a projection error. Moreover, the image projection technique was intraoperatively applied in 5 patients and was compared with a standard navigation system. Augmented reality visualization of the tumors succeeded in all cases. The mean time for registration was 3.8 minutes (range 2-7 minutes). The mean projection error was 0.8 ± 0.25 mm. There were no significant differences in accuracy according to the localization and size of the tumor. Clinical feasibility and reliability of the augmented reality system could be proved intraoperatively in 5 patients (projection error 1.2 ± 0.54 mm). The augmented reality system is accurate and reliable for the intraoperative projection of images to the head, skull, and brain surface. The ergonomic advantage of this technique improves the planning of neurosurgical procedures and enables the surgeon to use direct visualization for image-guided neurosurgery.

  12. Dynamic PET simulator via tomographic emission projection for kinetic modeling and parametric image studies.

    Science.gov (United States)

    Häggström, Ida; Beattie, Bradley J; Schmidtlein, C Ross

    2016-06-01

    To develop and evaluate a fast and simple tool called dpetstep (Dynamic PET Simulator of Tracers via Emission Projection), for dynamic PET simulations as an alternative to Monte Carlo (MC), useful for educational purposes and evaluation of the effects of the clinical environment, postprocessing choices, etc., on dynamic and parametric images. The tool was developed in matlab using both new and previously reported modules of petstep (PET Simulator of Tracers via Emission Projection). Time activity curves are generated for each voxel of the input parametric image, whereby effects of imaging system blurring, counting noise, scatters, randoms, and attenuation are simulated for each frame. Each frame is then reconstructed into images according to the user specified method, settings, and corrections. Reconstructed images were compared to MC data, and simple Gaussian noised time activity curves (GAUSS). dpetstep was 8000 times faster than MC. Dynamic images from dpetstep had a root mean square error that was within 4% on average of that of MC images, whereas the GAUSS images were within 11%. The average bias in dpetstep and MC images was the same, while GAUSS differed by 3% points. Noise profiles in dpetstep images conformed well to MC images, confirmed visually by scatter plot histograms, and statistically by tumor region of interest histogram comparisons that showed no significant differences (p dynamic PET and parametric images, and demonstrated that it generates both images and subsequent parametric images with very similar noise properties to those of MC images, in a fraction of the time. They believe dpetstep to be very useful for generating fast, simple, and realistic results, however since it uses simple scatter and random models it may not be suitable for studies investigating these phenomena. dpetstep can be downloaded free of cost from https://github.com/CRossSchmidtlein/dPETSTEP.

  13. WE-G-BRF-04: Robust Real-Time Volumetric Imaging Based On One Single Projection

    International Nuclear Information System (INIS)

    Xu, Y; Yan, H; Ouyang, L; Wang, J; Jiang, S; Jia, X; Zhou, L

    2014-01-01

    Purpose: Real-time volumetric imaging is highly desirable to provide instantaneous image guidance for lung radiation therapy. This study proposes a scheme to achieve this goal using one single projection by utilizing sparse learning and a principal component analysis (PCA) based lung motion model. Methods: A patient-specific PCA-based lung motion model is first constructed by analyzing deformable vector fields (DVFs) between a reference image and 4DCT images at each phase. At the training stage, we “learn” the relationship between the DVFs and the projection using sparse learning. Specifically, we first partition the projections into patches, and then apply sparse learning to automatically identify patches that best correlate with the principal components of the DVFs. Once the relationship is established, at the application stage, we first employ a patchbased intensity correction method to overcome the problem of different intensity scale between the calculated projection in the training stage and the measured projection in the application stage. The corrected projection image is then fed to the trained model to derive a DVF, which is applied to the reference image, yielding a volumetric image corresponding to the projection. We have validated our method through a NCAT phantom simulation case and one experiment case. Results: Sparse learning can automatically select those patches containing motion information, such as those around diaphragm. For the simulation case, over 98% of the lung region pass the generalized gamma test (10HU/1mm), indicating combined accuracy in both intensity and spatial domain. For the experimental case, the average tumor localization errors projected to the imager are 0.68 mm and 0.4 mm on the axial and tangential direction, respectively. Conclusion: The proposed method is capable of accurately generating a volumetric image using one single projection. It will potentially offer real-time volumetric image guidance to facilitate lung

  14. WE-G-BRF-04: Robust Real-Time Volumetric Imaging Based On One Single Projection

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y [UT Southwestern Medical Center, Dallas, TX (United States); Southern Medical University, Guangzhou (China); Yan, H; Ouyang, L; Wang, J; Jiang, S; Jia, X [UT Southwestern Medical Center, Dallas, TX (United States); Zhou, L [Southern Medical University, Guangzhou (China)

    2014-06-15

    Purpose: Real-time volumetric imaging is highly desirable to provide instantaneous image guidance for lung radiation therapy. This study proposes a scheme to achieve this goal using one single projection by utilizing sparse learning and a principal component analysis (PCA) based lung motion model. Methods: A patient-specific PCA-based lung motion model is first constructed by analyzing deformable vector fields (DVFs) between a reference image and 4DCT images at each phase. At the training stage, we “learn” the relationship between the DVFs and the projection using sparse learning. Specifically, we first partition the projections into patches, and then apply sparse learning to automatically identify patches that best correlate with the principal components of the DVFs. Once the relationship is established, at the application stage, we first employ a patchbased intensity correction method to overcome the problem of different intensity scale between the calculated projection in the training stage and the measured projection in the application stage. The corrected projection image is then fed to the trained model to derive a DVF, which is applied to the reference image, yielding a volumetric image corresponding to the projection. We have validated our method through a NCAT phantom simulation case and one experiment case. Results: Sparse learning can automatically select those patches containing motion information, such as those around diaphragm. For the simulation case, over 98% of the lung region pass the generalized gamma test (10HU/1mm), indicating combined accuracy in both intensity and spatial domain. For the experimental case, the average tumor localization errors projected to the imager are 0.68 mm and 0.4 mm on the axial and tangential direction, respectively. Conclusion: The proposed method is capable of accurately generating a volumetric image using one single projection. It will potentially offer real-time volumetric image guidance to facilitate lung

  15. Improvement of image quality using interpolated projection data estimation method in SPECT

    International Nuclear Information System (INIS)

    Takaki, Akihiro; Soma, Tsutomu; Murase, Kenya; Kojima, Akihiro; Asao, Kimie; Kamada, Shinya; Matsumoto, Masanori

    2009-01-01

    General data acquisition for single photon emission computed tomography (SPECT) is performed in 90 or 60 directions, with a coarse pitch of approximately 4-6 deg for a rotation of 360 deg or 180 deg, using a gamma camera. No data between adjacent projections will be sampled under these circumstances. The aim of the study was to develop a method to improve SPECT image quality by generating lacking projection data through interpolation of data obtained with a coarse pitch such as 6 deg. The projection data set at each individual degree in 360 directions was generated by a weighted average interpolation method from the projection data acquired with a coarse sampling angle (interpolated projection data estimation processing method, IPDE method). The IPDE method was applied to the numerical digital phantom data, actual phantom data and clinical brain data with Tc-99m ethyle cysteinate dimer (ECD). All SPECT images were reconstructed by the filtered back-projection method and compared with the original SPECT images. The results confirmed that streak artifacts decreased by apparently increasing a sampling number in SPECT after interpolation and also improved signal-to-noise (S/N) ratio of the root mean square uncertainty value. Furthermore, the normalized mean square error values, compared with standard images, had similar ones after interpolation. Moreover, the contrast and concentration ratios increased their effects after interpolation. These results indicate that effective improvement of image quality can be expected with interpolation. Thus, image quality and the ability to depict images can be improved while maintaining the present acquisition time and image quality. In addition, this can be achieved more effectively than at present even if the acquisition time is reduced. (author)

  16. Image reconstruction for digital breast tomosynthesis (DBT) by using projection-angle-dependent filter functions

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yeonok; Park, Chulkyu; Cho, Hyosung; Je, Uikyu; Hong, Daeki; Lee, Minsik; Cho, Heemoon; Choi, Sungil; Koo, Yangseo [Yonsei University, Wonju (Korea, Republic of)

    2014-09-15

    Digital breast tomosynthesis (DBT) is considered in clinics as a standard three-dimensional imaging modality, allowing the earlier detection of cancer. It typically acquires only 10-30 projections over a limited angle range of 15 - 60 .deg. with a stationary detector and typically uses a computationally-efficient filtered-backprojection (FBP) algorithm for image reconstruction. However, a common FBP algorithm yields poor image quality resulting from the loss of average image value and the presence of severe image artifacts due to the elimination of the dc component of the image by the ramp filter and to the incomplete data, respectively. As an alternative, iterative reconstruction methods are often used in DBT to overcome these difficulties, even though they are still computationally expensive. In this study, as a compromise, we considered a projection-angle dependent filtering method in which one-dimensional geometry-adapted filter kernels are computed with the aid of a conjugate-gradient method and are incorporated into the standard FBP framework. We implemented the proposed algorithm and performed systematic simulation works to investigate the imaging characteristics. Our results indicate that the proposed method is superior to a conventional FBP method for DBT imaging and has a comparable computational cost, while preserving good image homogeneity and edge sharpening with no serious image artifacts.

  17. Geophysical fluid dynamics

    CERN Document Server

    Pedlosky, Joseph

    1982-01-01

    The content of this book is based, largely, on the core curriculum in geophys­ ical fluid dynamics which land my colleagues in the Department of Geophysical Sciences at The University of Chicago have taught for the past decade. Our purpose in developing a core curriculum was to provide to advanced undergraduates and entering graduate students a coherent and systematic introduction to the theory of geophysical fluid dynamics. The curriculum and the outline of this book were devised to form a sequence of courses of roughly one and a half academic years (five academic quarters) in length. The goal of the sequence is to help the student rapidly advance to the point where independent study and research are practical expectations. It quickly became apparent that several topics (e. g. , some aspects of potential theory) usually thought of as forming the foundations of a fluid-dynamics curriculum were merely classical rather than essential and could be, however sadly, dispensed with for our purposes. At the same tim...

  18. Geophysical fluid dynamics

    CERN Document Server

    Pedlosky, Joseph

    1979-01-01

    The content of this book is based, largely, on the core curriculum in geophys­ ical fluid dynamics which I and my colleagues in the Department of Geophysical Sciences at The University of Chicago have taught for the past decade. Our purpose in developing a core curriculum was to provide to advanced undergraduates and entering graduate students a coherent and systematic introduction to the theory of geophysical fluid dynamics. The curriculum and the outline of this book were devised to form a sequence of courses of roughly one and a half academic years (five academic quarters) in length. The goal of the sequence is to help the student rapidly advance to the point where independent study and research are practical expectations. It quickly became apparent that several topics (e. g. , some aspects of potential theory) usually thought of as forming the foundations of a fluid-dynamics curriculum were merely classical rather than essential and could be, however sadly, dispensed with for our purposes. At the same ti...

  19. Coalescence measurements for evolving foams monitored by real-time projection imaging

    International Nuclear Information System (INIS)

    Myagotin, A; Helfen, L; Baumbach, T

    2009-01-01

    Real-time radiographic projection imaging together with novel spatio-temporal image analysis is presented to be a powerful technique for the quantitative analysis of coalescence processes accompanying the generation and temporal evolution of foams and emulsions. Coalescence events can be identified as discontinuities in a spatio-temporal image representing a sequence of projection images. Detection, identification of intensity and localization of the discontinuities exploit a violation criterion of the Fourier shift theorem and are based on recursive spatio-temporal image partitioning. The proposed method is suited for automated measurements of discontinuity rates (i.e., discontinuity intensity per unit time), so that large series of radiographs can be analyzed without user intervention. The application potential is demonstrated by the quantification of coalescence during the formation and decay of metal foams monitored by real-time x-ray radiography

  20. Improved detection of chronic myocardial infarction with Fourier amplitude and phase imaging in two projections

    International Nuclear Information System (INIS)

    Akins, E.W.; Scott, E.A.; Williams, C.M.

    1987-01-01

    Twenty-seven patients with 33 chronic myocaridal infarctions underwent MR imaging and radionuclide ventriculography at rest. The radionuclide ventriculographs, in left anterior oblique (LAO) and left posterior oblique (LPO) projections, were analyzed by two independent observers by visual inspection and combined Fourier-transformed amplitude and phase imaging. Only 15 (45%) of the 33 infarctions were detected by visual inspection, but 21 (64%) were detected on the LAO Fourier-transformed images along. Thirty (91%) were detected by using both LAO and LPO Fourier-transformed images. On MR imaging, 28 (85%) of the myocardial infarctions appeared as areas of focal wall thinning. Combined Fourier-transformed amplitude and phase imaging in both LAO and LPO views discloses more myocardial infarctions than visual inspection or LAO Fourier-transformed images alone because inferior infarctions, which are frequently missed in the LAO view, are easily seen in the LPO view

  1. WE-E-18A-11: Fluoro-Tomographic Images From Projections of On-Board Imager (OBI) While Gantry Is Moving

    Energy Technology Data Exchange (ETDEWEB)

    Yi, B; Hu, E; Yu, C; Lasio, G [Univ. of Maryland School Of Medicine, Baltimore, MD (United States)

    2014-06-15

    Purpose: A method to generate a series of fluoro-tomographic images (FTI) of the slice of interest (SOI) from the projection images of the On-board imager (OBI) while gantry is moving is developed and tested. Methods: Tomographic image via background subtraction, TIBS has been published by our group. TIBS uses a priori anatomical information from a previous CT scan to isolate a SOI from a planar kV image by factoring out the attenuations by tissues outside the SOI (background). We extended the idea to 4D TIBS, which enables to generate from the projection of different gantry angles. A set of background images for different angles are prepared. A background image at a given gantry angle is subtracted from the projection image at the same angle to generate a TIBS image. Then the TIBS image is converted to a reference angle. The 4D TIBS is the set of TIBS that originated from gantry angles other than the reference angle. Projection images of lung patients for CBCT acquisition are used to test the 4D TIBS. Results: Fluoroscopic images of a coronal plane of lung patients are acquired from the CBCT projections at different gantry angles and times. Change of morphology of hilar vessels due to breathing and heart beating are visible in the coronal plane, which are generated from the set of the projection images at gantry angles other than antero-posterior. Breathing surrogate or sorting process is not needed. Unlike tomosynthesis, FTI from 4D TIBS maintains the independence of each of the projections thereby reveals temporal variations within the SOI. Conclusion: FTI, fluoroscopic imaging of a SOI with x-ray projections, directly generated from the x-ray projection images at different gantry angles is tested with a lung case and proven feasible. This technique can be used for on-line imaging of moving targets. NIH Grant R01CA133539.

  2. Site characterization and validation - geophysical single hole logging

    International Nuclear Information System (INIS)

    Andersson, Per

    1989-05-01

    A total of 15 boreholes have been drilled for preliminary characterization of a previously unexplored site at the 360 and 385 m level in the Stripa mine. To adequately described the rock mass in the vicinity of these boreholes, a comprehensive program utilizing a large number of geophysical borehole methods has been carried out in 10 of these boreholes. The specific geophysical character of the rock mass and the major deformed units distinguished in the vicinity of the boreholes are recognized, and in certain cases also correlated between the boreholes. A general conclusion based on the geophysical logging results, made in this report, is that the preliminary predictions made in stage 2, of the site characterization and validation project (Olsson et.al, 1988), are adequate. The results from the geophysical logging can support the four predicted fracture/ fracture zones GHa, GHb, GA and GB whereas the predicted zones GC and GI are hard to confirm from the logging results. (author)

  3. Measurement of inter and intra fraction organ motion in radiotherapy using cone beam CT projection images

    International Nuclear Information System (INIS)

    Marchant, T E; Amer, A M; Moore, C J

    2008-01-01

    A method is presented for extraction of intra and inter fraction motion of seeds/markers within the patient from cone beam CT (CBCT) projection images. The position of the marker is determined on each projection image and fitted to a function describing the projection of a fixed point onto the imaging panel at different gantry angles. The fitted parameters provide the mean marker position with respect to the isocentre. Differences between the theoretical function and the actual projected marker positions are used to estimate the range of intra fraction motion and the principal motion axis in the transverse plane. The method was validated using CBCT projection images of a static marker at known locations and of a marker moving with known amplitude. The mean difference between actual and measured motion range was less than 1 mm in all directions, although errors of up to 5 mm were observed when large amplitude motion was present in an orthogonal direction. In these cases it was possible to calculate the range of motion magnitudes consistent with the observed marker trajectory. The method was shown to be feasible using clinical CBCT projections of a pancreas cancer patient

  4. Fluorescence In Situ Hybridization (FISH Signal Analysis Using Automated Generated Projection Images

    Directory of Open Access Journals (Sweden)

    Xingwei Wang

    2012-01-01

    Full Text Available Fluorescence in situ hybridization (FISH tests provide promising molecular imaging biomarkers to more accurately and reliably detect and diagnose cancers and genetic disorders. Since current manual FISH signal analysis is low-efficient and inconsistent, which limits its clinical utility, developing automated FISH image scanning systems and computer-aided detection (CAD schemes has been attracting research interests. To acquire high-resolution FISH images in a multi-spectral scanning mode, a huge amount of image data with the stack of the multiple three-dimensional (3-D image slices is generated from a single specimen. Automated preprocessing these scanned images to eliminate the non-useful and redundant data is important to make the automated FISH tests acceptable in clinical applications. In this study, a dual-detector fluorescence image scanning system was applied to scan four specimen slides with FISH-probed chromosome X. A CAD scheme was developed to detect analyzable interphase cells and map the multiple imaging slices recorded FISH-probed signals into the 2-D projection images. CAD scheme was then applied to each projection image to detect analyzable interphase cells using an adaptive multiple-threshold algorithm, identify FISH-probed signals using a top-hat transform, and compute the ratios between the normal and abnormal cells. To assess CAD performance, the FISH-probed signals were also independently visually detected by an observer. The Kappa coefficients for agreement between CAD and observer ranged from 0.69 to 1.0 in detecting/counting FISH signal spots in four testing samples. The study demonstrated the feasibility of automated FISH signal analysis that applying a CAD scheme to the automated generated 2-D projection images.

  5. Developments in geophysical exploration methods

    CERN Document Server

    1982-01-01

    One of the themes in current geophysical development is the bringing together of the results of observations made on the surface and those made in the subsurface. Several benefits result from this association. The detailed geological knowledge obtained in the subsurface can be extrapolated for short distances with more confidence when the geologi­ cal detail has been related to well-integrated subsurface and surface geophysical data. This is of value when assessing the characteristics of a partially developed petroleum reservoir. Interpretation of geophysical data is generally improved by the experience of seeing the surface and subsurface geophysical expression of a known geological configuration. On the theoretical side, the understanding of the geophysical processes themselves is furthered by the study of the phenomena in depth. As an example, the study of the progress of seismic wave trains downwards and upwards within the earth has proved most instructive. This set of original papers deals with some of ...

  6. An accelerated threshold-based back-projection algorithm for Compton camera image reconstruction

    International Nuclear Information System (INIS)

    Mundy, Daniel W.; Herman, Michael G.

    2011-01-01

    Purpose: Compton camera imaging (CCI) systems are currently under investigation for radiotherapy dose reconstruction and verification. The ability of such a system to provide real-time images during dose delivery will be limited by the computational speed of the image reconstruction algorithm. In this work, the authors present a fast and simple method by which to generate an initial back-projected image from acquired CCI data, suitable for use in a filtered back-projection algorithm or as a starting point for iterative reconstruction algorithms, and compare its performance to the current state of the art. Methods: Each detector event in a CCI system describes a conical surface that includes the true point of origin of the detected photon. Numerical image reconstruction algorithms require, as a first step, the back-projection of each of these conical surfaces into an image space. The algorithm presented here first generates a solution matrix for each slice of the image space by solving the intersection of the conical surface with the image plane. Each element of the solution matrix is proportional to the distance of the corresponding voxel from the true intersection curve. A threshold function was developed to extract those pixels sufficiently close to the true intersection to generate a binary intersection curve. This process is repeated for each image plane for each CCI detector event, resulting in a three-dimensional back-projection image. The performance of this algorithm was tested against a marching algorithm known for speed and accuracy. Results: The threshold-based algorithm was found to be approximately four times faster than the current state of the art with minimal deficit to image quality, arising from the fact that a generically applicable threshold function cannot provide perfect results in all situations. The algorithm fails to extract a complete intersection curve in image slices near the detector surface for detector event cones having axes nearly

  7. History of geophysical studies at the Waste Isolation Pilot Plant (WIPP), southeastern New Mexico

    International Nuclear Information System (INIS)

    Borns, D.J.

    1997-01-01

    A variety of geophysical methods including the spectrum of seismic, electrical, electromagnetic and potential field techniques have supported characterization, monitoring and experimental studies at the Waste Isolation Pilot Plant (WIPP). The geophysical studies have provided significant understanding of the nature of site deformation, tectonics and stability. Geophysical methods have delineated possible brine reservoirs beneath the underground facility and have defined the disturbed rock zone that forms around underground excavations. The role of geophysics in the WIPP project has evolved with the project. The early uses were for site characterization to satisfy site selection criteria or factors. As the regulatory framework for WIPP grew since 1980, the geophysics program supported experimental and field programs such as Salado hydrogeology and underground room systems and excavations. In summary, the major types of issues that geophysical studies addressed for WIPP are: Site Characterization; Castile Brine Reservoirs; Rustler/Dewey Lake Hydrogeology; Salado Hydrogeology; and Excavation Effects. The nature of geophysics programs for WIPP has been to support investigation rather than being the principal investigation itself. The geophysics program has been used to define conceptual models (e.g., the Disturbed Rock Zone-DRZ) or to test conceptual models (e.g., high transmissivity zones in the Rustler Formation). The geophysics program primarily supported larger characterization and experimental programs. Funding was not available for the complete documentation and interpretation. Therefore, a great deal of the geophysics survey information resides in contractor reports

  8. Using geophysical techniques to control in situ thermal remediation

    International Nuclear Information System (INIS)

    Boyd, S.; Daily, W.; Ramirez, A.; Wilt, M.; Goldman, R.; Kayes, D.; Kenneally, K.; Udell, K.; Hunter, R.

    1994-01-01

    Monitoring the thermal and hydrologic processes that occur during thermal environmental remediation programs in near real-time provides essential information for controlling the process. Geophysical techniques played a crucial role in process control as well as for characterization during the recent Dynamic Underground Stripping Project demonstration in which several thousand gallons of gasoline were removed from heterogeneous soils both above and below the water table. Dynamic Underground Stripping combines steam injection and electrical heating for thermal enhancement with ground water pumping and vacuum extraction for contaminant removal. These processes produce rapid changes in the subsurface properties including changes in temperature fluid saturation, pressure and chemistry. Subsurface imaging methods are used to map the heated zones and control the thermal process. Temperature measurements made in wells throughout the field reveal details of the complex heating phenomena. Electrical resistance tomography (ERT) provides near real-time detailed images of the heated zones between boreholes both during electrical heating and steam injection. Borehole induction logs show close correlation with lithostratigraphy and, by identifying the more permeable gravel zones, can be used to predict steam movement. They are also useful in understanding the physical changes in the field and in interpreting the ERT images. Tiltmeters provide additional information regarding the shape of the steamed zones in plan view. They were used to track the growth of the steam front from individual injectors

  9. JPEG2000-coded image error concealment exploiting convex sets projections.

    Science.gov (United States)

    Atzori, Luigi; Ginesu, Giaime; Raccis, Alessio

    2005-04-01

    Transmission errors in JPEG2000 can be grouped into three main classes, depending on the affected area: LL, high frequencies at the lower decomposition levels, and high frequencies at the higher decomposition levels. The first type of errors are the most annoying but can be concealed exploiting the signal spatial correlation like in a number of techniques proposed in the past; the second are less annoying but more difficult to address; the latter are often imperceptible. In this paper, we address the problem of concealing the second class or errors when high bit-planes are damaged by proposing a new approach based on the theory of projections onto convex sets. Accordingly, the error effects are masked by iteratively applying two procedures: low-pass (LP) filtering in the spatial domain and restoration of the uncorrupted wavelet coefficients in the transform domain. It has been observed that a uniform LP filtering brought to some undesired side effects that negatively compensated the advantages. This problem has been overcome by applying an adaptive solution, which exploits an edge map to choose the optimal filter mask size. Simulation results demonstrated the efficiency of the proposed approach.

  10. Sustainable Geophysical Observatory Networks

    Science.gov (United States)

    Willemann, R. J.; Lerner-Lam, A.; Aster, R.; Beck, S.; Ekstrom, G.; Nyblade, A.; Sandvol, E.

    2007-05-01

    Geophysical networks are defined not only by their technical specifications, but also by the characteristics and needs of the communities that use them. Growing populations supported by more elaborate urban infrastructure with its fine-grained socio-economic interdependencies and relying on global and regional connections for sustainability make new demands for natural hazard risk management. Taking advantage of advances in the underlying science to provide society with accurate risk assessments often requires higher fidelity measurements, entirely new types of observations, and an evolutionary sense of data products and information management. Engineering a high-tech system to address stakeholder needs is difficult, and designing for unpredictable developments requires an emphasis on adaptation. Thus, it is essential to promote formation of organizations or communities that can support evolution of a technological system, imagine new uses, and develop the societal relationships that sustain operations and provide capital for improvement. The owners must have a deep understanding of why the system works in particular ways and how to manage data products for the benefits of stakeholders. To be effective, community promotion must be sustained over a longer period of time than required to build a network and should be aimed at integrating the community into worldwide partnerships. Practices that can promote community formation if they are sustained include repeated training and scientific exchange workshops, extended visits by experts and staff at all levels to and from countries where networks are installed, mechanisms that make timely upgrades realistically possible, and routine exchange and wide dissemination of data in all directions. The combination of international research and educational collaborations, supported by open data exchange, with regionalized and specific assessments of local stakeholder needs and concerns, provides a sustainable model for

  11. Projection correction for the pixel-by-pixel basis in diffraction enhanced imaging

    International Nuclear Information System (INIS)

    Huang Zhifeng; Kang Kejun; Li Zheng

    2006-01-01

    Theories and methods of x-ray diffraction enhanced imaging (DEI) and computed tomography of the DEI (DEI-CT) have been investigated recently. But the phenomenon of projection offsets which may affect the accuracy of the results of extraction methods of refraction-angle images and reconstruction algorithms of the DEI-CT is seldom of concern. This paper focuses on it. Projection offsets are revealed distinctly according to the equivalent rectilinear propagation model of the DEI. Then, an effective correction method using the equivalent positions of projection data is presented to eliminate the errors induced by projection offsets. The correction method is validated by a computer simulation experiment and extraction methods or reconstruction algorithms based on the corrected data can give more accurate results. The limitations of the correction method are discussed at the end

  12. Restoration of the analytically reconstructed OpenPET images by the method of convex projections

    Energy Technology Data Exchange (ETDEWEB)

    Tashima, Hideaki; Murayama, Hideo; Yamaya, Taiga [National Institute of Radiological Sciences, Chiba (Japan); Katsunuma, Takayuki; Suga, Mikio [Chiba Univ. (Japan). Graduate School of Engineering; Kinouchi, Shoko [National Institute of Radiological Sciences, Chiba (Japan); Chiba Univ. (Japan). Graduate School of Engineering; Obi, Takashi [Tokyo Institute of Technology (Japan). Interdisciplinary Graduate School of Science and Engineering; Kudo, Hiroyuki [Tsukuba Univ. (Japan). Graduate School of Systems and Information Engineering

    2011-07-01

    We have proposed the OpenPET geometry which has gaps between detector rings and physically opened field-of-view. The image reconstruction of the OpenPET is classified into an incomplete problem because it does not satisfy the Orlov's condition. Even so, the simulation and experimental studies have shown that applying iterative methods such as the maximum likelihood expectation maximization (ML-EM) algorithm successfully reconstruct images in the gap area. However, the imaging process of the iterative methods in the OpenPET imaging is not clear. Therefore, the aim of this study is to analytically analyze the OpenPET imaging and estimate implicit constraints involved in the iterative methods. To apply explicit constraints in the OpenPET imaging, we used the method of convex projections for restoration of the images reconstructed by the analytical way in which low-frequency components are lost. Numerical simulations showed that the similar restoration effects are involved both in the ML-EM and the method of convex projections. Therefore, the iterative methods have advantageous effect of restoring lost frequency components of the OpenPET imaging. (orig.)

  13. Text extraction method for historical Tibetan document images based on block projections

    Science.gov (United States)

    Duan, Li-juan; Zhang, Xi-qun; Ma, Long-long; Wu, Jian

    2017-11-01

    Text extraction is an important initial step in digitizing the historical documents. In this paper, we present a text extraction method for historical Tibetan document images based on block projections. The task of text extraction is considered as text area detection and location problem. The images are divided equally into blocks and the blocks are filtered by the information of the categories of connected components and corner point density. By analyzing the filtered blocks' projections, the approximate text areas can be located, and the text regions are extracted. Experiments on the dataset of historical Tibetan documents demonstrate the effectiveness of the proposed method.

  14. Intensity-based bayesian framework for image reconstruction from sparse projection data

    International Nuclear Information System (INIS)

    Rashed, E.A.; Kudo, Hiroyuki

    2009-01-01

    This paper presents a Bayesian framework for iterative image reconstruction from projection data measured over a limited number of views. The classical Nyquist sampling rule yields the minimum number of projection views required for accurate reconstruction. However, challenges exist in many medical and industrial imaging applications in which the projection data is undersampled. Classical analytical reconstruction methods such as filtered backprojection (FBP) are not a good choice for use in such cases because the data undersampling in the angular range introduces aliasing and streak artifacts that degrade lesion detectability. In this paper, we propose a Bayesian framework for maximum likelihood-expectation maximization (ML-EM)-based iterative reconstruction methods that incorporates a priori knowledge obtained from expected intensity information. The proposed framework is based on the fact that, in tomographic imaging, it is often possible to expect a set of intensity values of the reconstructed object with relatively high accuracy. The image reconstruction cost function is modified to include the l 1 norm distance to the a priori known information. The proposed method has the potential to regularize the solution to reduce artifacts without missing lesions that cannot be expected from the a priori information. Numerical studies showed a significant improvement in image quality and lesion detectability under the condition of highly undersampled projection data. (author)

  15. Reconstruction of tomographic image from x-ray projections of a few views

    International Nuclear Information System (INIS)

    Kobayashi, Fujio; Yamaguchi, Shoichiro

    1982-01-01

    Computer tomographs have progressed rapidly, and in the latest high performance types, the photographing time has been shortened to less than 5 sec, but the clear images of hearts have not yet been obtained. The X-ray tomographs used so far irradiate X-ray from many directions and measure the projected data, but by limiting projection direction to a small number, it was planned to shorter the X-ray photographing time and to reduce X-ray exposure as the objective of this study. In this paper, a method is proposed, by which tomographic images are reconstructed from projected data in a small number of direction by generalized inverse matrix penalty method. This method is the calculation method newly devised by the authors for this purpose. It is a kind of the nonlinear planning method added with the restrictive condition using a generalized inverse matrix, and it is characterized by the simple calculation procedure and rapid convergence. Moreover, the effect on reconstructed images when errors are included in projected data was examined. Also, the simple computer simulation to reconstruct tomographic images using the projected data in four directions was performed, and the usefulness of this method was confirmed. It contributes to the development of superhigh speed tomographs in future. (Kako, I.)

  16. Image reconstruction from projections and its application in emission computer tomography

    International Nuclear Information System (INIS)

    Kuba, Attila; Csernay, Laszlo

    1989-01-01

    Computer tomography is an imaging technique for producing cross sectional images by reconstruction from projections. Its two main branches are called transmission and emission computer tomography, TCT and ECT, resp. After an overview of the theory and practice of TCT and ECT, the first Hungarian ECT type MB 9300 SPECT consisting of a gamma camera and Ketronic Medax N computer is described, and its applications to radiological patient observations are discussed briefly. (R.P.) 28 refs.; 4 figs

  17. Optimized image acquisition for breast tomosynthesis in projection and reconstruction space

    OpenAIRE

    Chawla, Amarpreet S.; Lo, Joseph Y.; Baker, Jay A.; Samei, Ehsan

    2009-01-01

    Breast tomosynthesis has been an exciting new development in the field of breast imaging. While the diagnostic improvement via tomosynthesis is notable, the full potential of tomosynthesis has not yet been realized. This may be attributed to the dependency of the diagnostic quality of tomosynthesis on multiple variables, each of which needs to be optimized. Those include dose, number of angular projections, and the total angular span of those projections. In this study, the authors investigat...

  18. ANNALS OF GEOPHYSICS: AD MAJORA

    Directory of Open Access Journals (Sweden)

    Fabio Florindo

    2014-03-01

    Full Text Available Annals of Geophysics is a bimonthly international journal, which publishes scientific papers in the field of geophysics sensu lato. It derives from Annali di Geofisica, which commenced publication in January 1948 as a quarterly periodical devoted to general geophysics, seismology, earth magnetism, and atmospheric studies. The journal was published regularly for a quarter of a century until 1982 when it merged with the French journal Annales de Géophysique to become Annales Geophysicae under the aegis of the European Geophysical Society. In 1981, this journal ceased publication of the section on solid earth geophysics, ending the legacy of Annali di Geofisica. In 1993, the Istituto Nazionale di Geofisica (ING, founder of the journal, decided to resume publication of its own journal under the same name, Annali di Geofisica. To ensure continuity, the first volume of the new series was assigned the volume number XXXVI (following the last issue published in 1982. In 2002, with volume XLV, the name of the journal was translated into English to become Annals of Geophysics and in consequence the journal impact factor counter was restarted. Starting in 2010, in order to improve its status and better serve the science community, Annals of Geophysics has instituted a number of editorial changes including full electronic open access, freely accessible online, the possibility to comment on and discuss papers online, and a board of editors representing Asia and the Americas as well as Europe. [...

  19. Decoding using back-project algorithm from coded image in ICF

    International Nuclear Information System (INIS)

    Jiang shaoen; Liu Zhongli; Zheng Zhijian; Tang Daoyuan

    1999-01-01

    The principle of the coded imaging and its decoding in inertial confinement fusion is described simply. The authors take ring aperture microscope for example and use back-project (BP) algorithm to decode the coded image. The decoding program has been performed for numerical simulation. Simulations of two models are made, and the results show that the accuracy of BP algorithm is high and effect of reconstruction is good. Thus, it indicates that BP algorithm is applicable to decoding for coded image in ICF experiments

  20. Improvement of image quality of holographic projection on tilted plane using iterative algorithm

    Science.gov (United States)

    Pang, Hui; Cao, Axiu; Wang, Jiazhou; Zhang, Man; Deng, Qiling

    2017-12-01

    Holographic image projection on tilted plane has an important application prospect. In this paper, we propose a method to compute the phase-only hologram that can reconstruct a clear image on tilted plane. By adding a constant phase to the target image of the inclined plane, the corresponding light field distribution on the plane that is parallel to the hologram plane is derived through the titled diffraction calculation. Then the phase distribution of the hologram is obtained by the iterative algorithm with amplitude and phase constrain. Simulation and optical experiment are performed to show the effectiveness of the proposed method.

  1. Airborne geophysics in Australia: the government contribution

    International Nuclear Information System (INIS)

    Denham, D.

    1997-01-01

    Airborne geophysical data sets provide important cost-effective information for resource exploration and land management. Improved techniques, developed recently, now enable high-resolution aeromagnetic and gamma-ray surveys to be used extensively by the resource industries to improve the cost effectiveness of exploration and by governments to encourage resource development and sustainable management of natural resources. Although airborne geophysical techniques have been used extensively and are now used almost routinely by mineral explorers, it is only in the last few years that governments have been involved as major players in the acquisition of data. The exploration industry pioneered the imaging of high-resolution airborne geophysical data sets in the early 1980s and, at the same time, the Northern Territory Government started a modest program of flying the Northern Territory, at 500 m flight-line spacing, to attract mineral exploration. After the start of the National Geoscience Mapping Accord in 1990, the then BMR and its State/Territory counterparts used the new high-resolution data as an essential ingredient to underpin mapping programs. These new data sets proved so valuable that, starting in 1992/93, the annual expenditure by the Commonwealth and States/Northern Territory increased from roughly $2 million per year to a massive $10 million per year. These investments by governments, although unlikely to be permanently sustainable, have been made to encourage and expand exploration activity by providing new high-quality data sets in industry at very low cost. There are now approximately 11 million line-km of airborne geophysical data available in databases held by the Commonwealth, States and Northern Territory. The results so far have seen a significant increase in exploration activity in States that have embarked on this course (e.g. South Australia and Victoria), and the information provided from these surveys is proving crucial to understanding the

  2. Dynamic PET simulator via tomographic emission projection for kinetic modeling and parametric image studies

    Energy Technology Data Exchange (ETDEWEB)

    Häggström, Ida, E-mail: haeggsti@mskcc.org [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 and Department of Radiation Sciences, Umeå University, Umeå 90187 (Sweden); Beattie, Bradley J.; Schmidtlein, C. Ross [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States)

    2016-06-15

    Purpose: To develop and evaluate a fast and simple tool called dPETSTEP (Dynamic PET Simulator of Tracers via Emission Projection), for dynamic PET simulations as an alternative to Monte Carlo (MC), useful for educational purposes and evaluation of the effects of the clinical environment, postprocessing choices, etc., on dynamic and parametric images. Methods: The tool was developed in MATLAB using both new and previously reported modules of PETSTEP (PET Simulator of Tracers via Emission Projection). Time activity curves are generated for each voxel of the input parametric image, whereby effects of imaging system blurring, counting noise, scatters, randoms, and attenuation are simulated for each frame. Each frame is then reconstructed into images according to the user specified method, settings, and corrections. Reconstructed images were compared to MC data, and simple Gaussian noised time activity curves (GAUSS). Results: dPETSTEP was 8000 times faster than MC. Dynamic images from dPETSTEP had a root mean square error that was within 4% on average of that of MC images, whereas the GAUSS images were within 11%. The average bias in dPETSTEP and MC images was the same, while GAUSS differed by 3% points. Noise profiles in dPETSTEP images conformed well to MC images, confirmed visually by scatter plot histograms, and statistically by tumor region of interest histogram comparisons that showed no significant differences (p < 0.01). Compared to GAUSS, dPETSTEP images and noise properties agreed better with MC. Conclusions: The authors have developed a fast and easy one-stop solution for simulations of dynamic PET and parametric images, and demonstrated that it generates both images and subsequent parametric images with very similar noise properties to those of MC images, in a fraction of the time. They believe dPETSTEP to be very useful for generating fast, simple, and realistic results, however since it uses simple scatter and random models it may not be suitable for

  3. Dynamic PET simulator via tomographic emission projection for kinetic modeling and parametric image studies

    International Nuclear Information System (INIS)

    Häggström, Ida; Beattie, Bradley J.; Schmidtlein, C. Ross

    2016-01-01

    Purpose: To develop and evaluate a fast and simple tool called dPETSTEP (Dynamic PET Simulator of Tracers via Emission Projection), for dynamic PET simulations as an alternative to Monte Carlo (MC), useful for educational purposes and evaluation of the effects of the clinical environment, postprocessing choices, etc., on dynamic and parametric images. Methods: The tool was developed in MATLAB using both new and previously reported modules of PETSTEP (PET Simulator of Tracers via Emission Projection). Time activity curves are generated for each voxel of the input parametric image, whereby effects of imaging system blurring, counting noise, scatters, randoms, and attenuation are simulated for each frame. Each frame is then reconstructed into images according to the user specified method, settings, and corrections. Reconstructed images were compared to MC data, and simple Gaussian noised time activity curves (GAUSS). Results: dPETSTEP was 8000 times faster than MC. Dynamic images from dPETSTEP had a root mean square error that was within 4% on average of that of MC images, whereas the GAUSS images were within 11%. The average bias in dPETSTEP and MC images was the same, while GAUSS differed by 3% points. Noise profiles in dPETSTEP images conformed well to MC images, confirmed visually by scatter plot histograms, and statistically by tumor region of interest histogram comparisons that showed no significant differences (p < 0.01). Compared to GAUSS, dPETSTEP images and noise properties agreed better with MC. Conclusions: The authors have developed a fast and easy one-stop solution for simulations of dynamic PET and parametric images, and demonstrated that it generates both images and subsequent parametric images with very similar noise properties to those of MC images, in a fraction of the time. They believe dPETSTEP to be very useful for generating fast, simple, and realistic results, however since it uses simple scatter and random models it may not be suitable for

  4. Unleashing Geophysics Data with Modern Formats and Services

    Science.gov (United States)

    Ip, Alex; Brodie, Ross C.; Druken, Kelsey; Bastrakova, Irina; Evans, Ben; Kemp, Carina; Richardson, Murray; Trenham, Claire; Wang, Jingbo; Wyborn, Lesley

    2016-04-01

    Geoscience Australia (GA) is the national steward of large volumes of geophysical data extending over the entire Australasian region and spanning many decades. The volume and variety of data which must be managed, coupled with the increasing need to support machine-to-machine data access, mean that the old "click-and-ship" model delivering data as downloadable files for local analysis is rapidly becoming unviable - a "big data" problem not unique to geophysics. The Australian Government, through the Research Data Services (RDS) Project, recently funded the Australian National Computational Infrastructure (NCI) to organize a wide range of Earth Systems data from diverse collections including geoscience, geophysics, environment, climate, weather, and water resources onto a single High Performance Data (HPD) Node. This platform, which now contains over 10 petabytes of data, is called the National Environmental Research Data Interoperability Platform (NERDIP), and is designed to facilitate broad user access, maximise reuse, and enable integration. GA has contributed several hundred terabytes of geophysical data to the NERDIP. Historically, geophysical datasets have been stored in a range of formats, with metadata of varying quality and accessibility, and without standardised vocabularies. This has made it extremely difficult to aggregate original data from multiple surveys (particularly un-gridded geophysics point/line data) into standard formats suited to High Performance Computing (HPC) environments. To address this, it was decided to use the NERDIP-preferred Hierarchical Data Format (HDF) 5, which is a proven, standard, open, self-describing and high-performance format supported by extensive software tools, libraries and data services. The Network Common Data Form (NetCDF) 4 API facilitates the use of data in HDF5, whilst the NetCDF Climate & Forecasting conventions (NetCDF-CF) further constrain NetCDF4/HDF5 data so as to provide greater inherent interoperability

  5. EISCAT Aperture Synthesis Imaging (EASI _3D) for the EISCAT_3D Project

    Science.gov (United States)

    La Hoz, Cesar; Belyey, Vasyl

    2012-07-01

    Aperture Synthesis Imaging Radar (ASIR) is one of the technologies adopted by the EISCAT_3D project to endow it with imaging capabilities in 3-dimensions that includes sub-beam resolution. Complemented by pulse compression, it will provide 3-dimensional images of certain types of incoherent scatter radar targets resolved to about 100 metres at 100 km range, depending on the signal-to-noise ratio. This ability will open new research opportunities to map small structures associated with non-homogeneous, unstable processes such as aurora, summer and winter polar radar echoes (PMSE and PMWE), Natural Enhanced Ion Acoustic Lines (NEIALs), structures excited by HF ionospheric heating, meteors, space debris, and others. The underlying physico-mathematical principles of the technique are the same as the technique employed in radioastronomy to image stellar objects; both require sophisticated inversion techniques to obtain reliable images.

  6. Dynamic Underground Stripping Demonstration Project

    International Nuclear Information System (INIS)

    Aines, R.; Newmark, R.; McConachie, W.; Rice, D.; Ramirez, A.; Siegel, W.; Buettner, M.; Daily, W.; Krauter, P.; Folsom, E.; Boegel, A.J.; Bishop, D.; udel, K.

    1992-03-01

    LLNL is collaborating with the UC Berkeley College of Engineering to develop and demonstrate a system of thermal remediation and underground imaging techniques for use in rapid cleanup of localized underground spills. Called ''Dynamic Stripping'' to reflect the rapid and controllable nature of the process, it will combine steam injection, direct electrical heating, and tomographic geophysical imaging in a cleanup of the LLNL gasoline spill. In the first 8 months of the project, a Clean Site engineering test was conducted to prove the field application of the techniques before moving to the contaminated site in FY 92

  7. Detection of pulmonary nodules at paediatric CT: maximum intensity projections and axial source images are complementary

    International Nuclear Information System (INIS)

    Kilburn-Toppin, Fleur; Arthurs, Owen J.; Tasker, Angela D.; Set, Patricia A.K.

    2013-01-01

    Maximum intensity projection (MIP) images might be useful in helping to differentiate small pulmonary nodules from adjacent vessels on thoracic multidetector CT (MDCT). The aim was to evaluate the benefits of axial MIP images over axial source images for the paediatric chest in an interobserver variability study. We included 46 children with extra-pulmonary solid organ malignancy who had undergone thoracic MDCT. Three radiologists independently read 2-mm axial and 10-mm MIP image datasets, recording the number of nodules, size and location, overall time taken and confidence. There were 83 nodules (249 total reads among three readers) in 46 children (mean age 10.4 ± 4.98 years, range 0.3-15.9 years; 24 boys). Consensus read was used as the reference standard. Overall, three readers recorded significantly more nodules on MIP images (228 vs. 174; P < 0.05), improving sensitivity from 67% to 77.5% (P < 0.05) but with lower positive predictive value (96% vs. 85%, P < 0.005). MIP images took significantly less time to read (71.6 ± 43.7 s vs. 92.9 ± 48.7 s; P < 0.005) but did not improve confidence levels. Using 10-mm axial MIP images for nodule detection in the paediatric chest enhances diagnostic performance, improving sensitivity and reducing reading time when compared with conventional axial thin-slice images. Axial MIP and axial source images are complementary in thoracic nodule detection. (orig.)

  8. Motion nature projection reduces patient's psycho-physiological anxiety during CT imaging.

    NARCIS (Netherlands)

    Zijlstra, Emma; Hagedoorn, Mariët; Krijnen, Wim; van der Schans, Cees; Mobach, Mark P.

    2017-01-01

    A growing body of evidence indicates that natural environments can positively influence people. This study investigated whether the use of motion nature projection in computed tomography (CT) imaging rooms is effective in mitigating psycho-physiological anxiety (vs. no intervention) using a

  9. Modeling and Evaluation of Geophysical Methods for Monitoring and Tracking CO2 Migration

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, Jeff

    2012-11-30

    Geological sequestration has been proposed as a viable option for mitigating the vast amount of CO{sub 2} being released into the atmosphere daily. Test sites for CO{sub 2} injection have been appearing across the world to ascertain the feasibility of capturing and sequestering carbon dioxide. A major concern with full scale implementation is monitoring and verifying the permanence of injected CO{sub 2}. Geophysical methods, an exploration industry standard, are non-invasive imaging techniques that can be implemented to address that concern. Geophysical methods, seismic and electromagnetic, play a crucial role in monitoring the subsurface pre- and post-injection. Seismic techniques have been the most popular but electromagnetic methods are gaining interest. The primary goal of this project was to develop a new geophysical tool, a software program called GphyzCO2, to investigate the implementation of geophysical monitoring for detecting injected CO{sub 2} at test sites. The GphyzCO2 software consists of interconnected programs that encompass well logging, seismic, and electromagnetic methods. The software enables users to design and execute 3D surface-to-surface (conventional surface seismic) and borehole-to-borehole (cross-hole seismic and electromagnetic methods) numerical modeling surveys. The generalized flow of the program begins with building a complex 3D subsurface geological model, assigning properties to the models that mimic a potential CO{sub 2} injection site, numerically forward model a geophysical survey, and analyze the results. A test site located in Warren County, Ohio was selected as the test site for the full implementation of GphyzCO2. Specific interest was placed on a potential reservoir target, the Mount Simon Sandstone, and cap rock, the Eau Claire Formation. Analysis of the test site included well log data, physical property measurements (porosity), core sample resistivity measurements, calculating electrical permittivity values, seismic data

  10. Reconstruction of implanted marker trajectories from cone-beam CT projection images using interdimensional correlation modeling

    International Nuclear Information System (INIS)

    Chung, Hyekyun; Poulsen, Per Rugaard; Keall, Paul J.; Cho, Seungryong; Cho, Byungchul

    2016-01-01

    Purpose: Cone-beam CT (CBCT) is a widely used imaging modality for image-guided radiotherapy. Most vendors provide CBCT systems that are mounted on a linac gantry. Thus, CBCT can be used to estimate the actual 3-dimensional (3D) position of moving respiratory targets in the thoracic/abdominal region using 2D projection images. The authors have developed a method for estimating the 3D trajectory of respiratory-induced target motion from CBCT projection images using interdimensional correlation modeling. Methods: Because the superior–inferior (SI) motion of a target can be easily analyzed on projection images of a gantry-mounted CBCT system, the authors investigated the interdimensional correlation of the SI motion with left–right and anterior–posterior (AP) movements while the gantry is rotating. A simple linear model and a state-augmented model were implemented and applied to the interdimensional correlation analysis, and their performance was compared. The parameters of the interdimensional correlation models were determined by least-square estimation of the 2D error between the actual and estimated projected target position. The method was validated using 160 3D tumor trajectories from 46 thoracic/abdominal cancer patients obtained during CyberKnife treatment. The authors’ simulations assumed two application scenarios: (1) retrospective estimation for the purpose of moving tumor setup used just after volumetric matching with CBCT; and (2) on-the-fly estimation for the purpose of real-time target position estimation during gating or tracking delivery, either for full-rotation volumetric-modulated arc therapy (VMAT) in 60 s or a stationary six-field intensity-modulated radiation therapy (IMRT) with a beam delivery time of 20 s. Results: For the retrospective CBCT simulations, the mean 3D root-mean-square error (RMSE) for all 4893 trajectory segments was 0.41 mm (simple linear model) and 0.35 mm (state-augmented model). In the on-the-fly simulations, prior

  11. Reconstruction of implanted marker trajectories from cone-beam CT projection images using interdimensional correlation modeling

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Hyekyun [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea and Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Poulsen, Per Rugaard [Department of Oncology, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C (Denmark); Keall, Paul J. [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, NSW 2006 (Australia); Cho, Seungryong [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141 (Korea, Republic of); Cho, Byungchul, E-mail: cho.byungchul@gmail.com, E-mail: bcho@amc.seoul.kr [Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505 (Korea, Republic of)

    2016-08-15

    Purpose: Cone-beam CT (CBCT) is a widely used imaging modality for image-guided radiotherapy. Most vendors provide CBCT systems that are mounted on a linac gantry. Thus, CBCT can be used to estimate the actual 3-dimensional (3D) position of moving respiratory targets in the thoracic/abdominal region using 2D projection images. The authors have developed a method for estimating the 3D trajectory of respiratory-induced target motion from CBCT projection images using interdimensional correlation modeling. Methods: Because the superior–inferior (SI) motion of a target can be easily analyzed on projection images of a gantry-mounted CBCT system, the authors investigated the interdimensional correlation of the SI motion with left–right and anterior–posterior (AP) movements while the gantry is rotating. A simple linear model and a state-augmented model were implemented and applied to the interdimensional correlation analysis, and their performance was compared. The parameters of the interdimensional correlation models were determined by least-square estimation of the 2D error between the actual and estimated projected target position. The method was validated using 160 3D tumor trajectories from 46 thoracic/abdominal cancer patients obtained during CyberKnife treatment. The authors’ simulations assumed two application scenarios: (1) retrospective estimation for the purpose of moving tumor setup used just after volumetric matching with CBCT; and (2) on-the-fly estimation for the purpose of real-time target position estimation during gating or tracking delivery, either for full-rotation volumetric-modulated arc therapy (VMAT) in 60 s or a stationary six-field intensity-modulated radiation therapy (IMRT) with a beam delivery time of 20 s. Results: For the retrospective CBCT simulations, the mean 3D root-mean-square error (RMSE) for all 4893 trajectory segments was 0.41 mm (simple linear model) and 0.35 mm (state-augmented model). In the on-the-fly simulations, prior

  12. Three-dimensional DNA image cytometry by optical projection tomographic microscopy for early cancer diagnosis.

    Science.gov (United States)

    Agarwal, Nitin; Biancardi, Alberto M; Patten, Florence W; Reeves, Anthony P; Seibel, Eric J

    2014-04-01

    Aneuploidy is typically assessed by flow cytometry (FCM) and image cytometry (ICM). We used optical projection tomographic microscopy (OPTM) for assessing cellular DNA content using absorption and fluorescence stains. OPTM combines some of the attributes of both FCM and ICM and generates isometric high-resolution three-dimensional (3-D) images of single cells. Although the depth of field of the microscope objective was in the submicron range, it was extended by scanning the objective's focal plane. The extended depth of field image is similar to a projection in a conventional x-ray computed tomography. These projections were later reconstructed using computed tomography methods to form a 3-D image. We also present an automated method for 3-D nuclear segmentation. Nuclei of chicken, trout, and triploid trout erythrocyte were used to calibrate OPTM. Ratios of integrated optical densities extracted from 50 images of each standard were compared to ratios of DNA indices from FCM. A comparison of mean square errors with thionin, hematoxylin, Feulgen, and SYTOX green was done. Feulgen technique was preferred as it showed highest stoichiometry, least variance, and preserved nuclear morphology in 3-D. The addition of this quantitative biomarker could further strengthen existing classifiers and improve early diagnosis of cancer using 3-D microscopy.

  13. Direct image reconstruction with limited angle projection data for computerized tomography

    International Nuclear Information System (INIS)

    Inouye, T.

    1980-01-01

    Discussions are made on the minimum angle range for projection data necessary to reconstruct the complete CT image. As is easily shown from the image reconstruction theorem, the lack of projection angle provides no data for the Fourier transformed function of the object on the corresponding angular directions, where the projections are missing. In a normal situation, the Fourier transformed function of an object image holds an analytic characteristic with respect to two-dimensional orthogonal parameters. This characteristic enables uniquely prolonging the function outside the obtained region employing a sort of analytic continuation with respect to both parameters. In the method reported here, an object pattern, which is confined within a finite range, is shifted to a specified region to have complete orthogonal function expansions without changing the projection angle directions. These orthogonal functions are analytically extended to the missing projection angle range and the whole function is determined. This method does not include any estimation process, whose effectiveness is often seriously jeopardized by the presence of a slight fluctuation component. Computer simulations were carried out to demonstrate the effectiveness of the method

  14. Shallow Depth Geophysical Investigation Through the Application of Magnetic and Electric Resistance Techniques: AN Evaluation Study of the Responses of Magnetic and Electric Resistance Techniques to Archaeogeophysical Prospection Surveys in Greece and Cyprus

    Science.gov (United States)

    Sarris, Apostolos

    particular anomalies and helped in the systematic recognition of similar features. The proposed filtering processes yielded fairly good results delineating the dimensions of the concealed targets, emphasized different kinds of anomalies and helped considerably in the interpretation of the geophysical maps and the subsequent archaeological excavations. The effectiveness of each technique to detect magnetic susceptibility and electric resistivity contrasts has been proven to be extremely successful. This research project has shown the potential importance of the geophysical investigations and imaging techniques in shallow depth prospecting. Image enhancement and mapping of the corresponding anomalies can reveal an accurate representation of the subsurface features. The re-evaluation of the geophysical data under the combination of different techniques has proven fruitful and instructive for future geophysical studies.

  15. A ''model'' geophysics program

    International Nuclear Information System (INIS)

    Nyquist, J.E.

    1994-01-01

    In 1993, I tested a radio-controlled airplane designed by Jim Walker of Brigham Young University for low-elevation aerial photography. Model-air photography retains most of the advantages of standard aerial photography --- the photographs can be used to detect lineaments, to map roads and buildings, and to construct stereo pairs to measure topography --- and it is far less expensive. Proven applications on the Oak Ridge Reservation include: updating older aerial records to document new construction; using repeated overflights of the same area to capture seasonal changes in vegetation and the effects of major storms; and detecting waste trench boundaries from the color and character of the overlying grass. Aerial photography is only one of many possible applications of radio-controlled aircraft. Currently, I am funded by the Department of Energy's Office of Technology Development to review the state of the art in microavionics, both military and civilian, to determine ways this emerging technology can be used for environmental site characterization. Being particularly interested in geophysical applications, I am also collaborating with electrical engineers at Oak Ridge National Laboratory to design a model plane that will carry a 3-component flux-gate magnetometer and a global positioning system, which I hope to test in the spring of 1994

  16. GEOPHYSICAL PROPERTIES OF SOILS

    KAUST Repository

    Santamarina, Carlos

    2016-12-01

    Low energy perturbations used in geophysical methods provide insightful information about constant-fabric soil properties and their spatial variability. There are causal links between soil type, index properties, elastic wave velocity, electromagnetic wave parameters and thermal properties. Soil type relates to the stress-dependent S-wave velocity, thermal and electrical conductivity and permittivity. The small strain stiffness reflects the state of stress, the extent of diagenetic cementation and/or freezing. Pore fluid chemistry, fluid phase and changes in either fluid chemistry or phase manifest through electromagnetic measurements. The volumetric water content measured with electromagnetic techniques is the best predictor of porosity if the water saturation is 100%. Changes in water saturation alter the P-wave velocity when Srà100%, the S-wave velocity at intermediate saturations, and the thermal conductivity when the saturation is low Srà0%. Finally, tabulated values suffice to estimate heat capacity and latent heat for engineering design, however thermal conductivity requires measurements under proper field conditions.

  17. Karoo airborne geophysical survey

    International Nuclear Information System (INIS)

    Cole, D.J.; Stettler, E.H.

    1984-01-01

    Thirty four uranium anomalies were selected for ground follow-up from the analogue spectrometer records of Block 4 of the Karoo Airborne Geophysical Survey. The anomalies were plotted on 1:50 000 scale topographic maps and to 1:250 000 scale maps which are included in this report. The anomaly co-ordinates are tabulated together with the farms on which they occur. Results of the ground follow-up of the aerial anomalies are described. Twenty two anomalies are related to uranium mineralisation of which seventeen occur over baked mudstone adjacent to a dolerite intrusion. Five are located over fluvial channel sandstone of the Beaufort Group and subsurface mineralised sandstone may be present. The other twelve anomalies are spurious. Of the anomalies located over baked mudstone, fifteen emanate from ferruginous mudstone of the Whitehill Formation west of longitude 21 degrees 15 minutes. One of the two remaining anomalies over baked mudstone occurs over the Prince Albert Formation and the other anomaly is over baked mudstone and calcareous nodules of the Beaufort Group. The general low uranium values (less than 355 ppm eU3O8) render the occurrences uneconomic

  18. Jesuit Geophysical Observatories

    Science.gov (United States)

    Udias, Agustin; Stauder, William

    Jesuits have had ah interest in observing and explaining geophysical phenomena since this religious order, the Society of Jesus, was founded by Ignatius of Loyola in 1540. Three principal factors contributed to this interest: their educational work in colleges and universities, their missionary endeavors to remote lands where they observed interesting and often as yet undocumented natural phenomena, and a network of communication that brought research of other Jesuits readily to their awareness.One of the first and most important Jesuit colleges was the Roman College (today the Gregorian University) founded in 1551 in Rome, which served as a model for many other universities throughout the world. By 1572, Christopher Clavius (1537-1612), professor of mathematics at the Roman College, had already initiated an important tradition of Jesuit research by emphasizing applied mathematics and insisting on the need of serious study of mathematics in the program of studies in the humanities. In 1547 he directed a publication of Euclid's work with commentaries, and published several treatises on mathematics, including Arithmetica Practica [1585], Gnomonicae [1581], and Geometrica Practica [1606]. Clavius was also a Copernican and supported his friend Galileo when he announced the discovery of the satellites of Jupiter.

  19. A review of nuclear geophysics

    International Nuclear Information System (INIS)

    Clayton, C.G.; Schweitzer, J.S.

    1992-01-01

    This paper summarizes the development of nuclear geophysics in scientific and technological content and in range from its beginnings early in this century to the present day. We note that the early work in nuclear geophysics was originally referred to under the umbrella of open-quotes isotope applicationsclose quotes and the origin of the term open-quotes nuclear geophysicsclose quotes (which is seen to clarify and to focus work in this area) is exposed in this paper. The current expansion of nuclear geophysics front its original concern with oil well logging is an important trend because much of the underlying science, technology, and instrumentation is common ground. A review of nuclear geophysics would be a barren document without reference to long-term and, in some cases, short-term commercial and economic as well as to technological considerations, since these factors are the principal motivation for further development

  20. Comprehensive surface geophysical investigation of karst caves ahead of the tunnel face: A case study in the Xiaoheyan section of the water supply project from Songhua River, Jilin, China

    Science.gov (United States)

    Bin, Liu; Zhengyu, Liu; Shucai, Li; Lichao, Nie; Maoxin, Su; Huaifeng, Sun; Kerui, Fan; Xinxin, Zhang; Yonghao, Pang

    2017-09-01

    This paper describes the application of a comprehensive surface geophysical investigation of underground karst systems ahead of the tunnel face in the Xiaoheyan section in the main line of the water supply project from Songhua River, located in Jilin, China. To make an accurate investigation, Surface Electrical Resistivity Tomography (S-ERT), Transient Electromagnetic Method (TEM), Geological Drilling (Geo-D) and Three-dimensional Cross-hole Electrical Resistivity Tomography (3D cross-hole ERT) were applied to gain a comprehensive interpretation. To begin with, S-ERT and TEM are adopted to detect and delineate the underground karst zone. Based on the detection results, surface and in-tunnel Geo-D are placed in major areas with more specific and accurate information gained. After that, survey lines of 3D cross-hole ERT are used to conduct detailed exploration towards underground karst system. In the comprehensive investigation, it is the major question to make the best of prior information so as to promote the quality of detection. The paper has put forward strategies to make the full use of effective information in data processing and the main ideas of those strategies include: (1) Take the resistivity distribution of the subsurface stratum gained by S-ERT inversion as the initial model of TEM inversion; (2) Arrange borehole positions with the results of S-ERT and TEM. After that, gain more accurate information about resistivity of subsurface stratum using those boreholes located; (3) Through the comprehensive analysis of the information about S-ERT, TEM and Geo-D, set the initial model of 3D cross-hole resistivity inversion and meanwhile, gain the variation range of stratum resistivity. At last, a 3D cross-hole resistivity inversion based on the incorporated initial model and inequality constraint is conducted. Constrained inversion and joint interpretation are realized by the effective use of prior information in comprehensive investigation, helping to suppress

  1. Survey of on-road image projection with pixel light systems

    Science.gov (United States)

    Rizvi, Sadiq; Knöchelmann, Marvin; Ley, Peer-Phillip; Lachmayer, Roland

    2017-12-01

    HID, LED and laser-based high resolution automotive headlamps, as of late known as `pixel light systems', are at the forefront of the developing technologies paving the way for autonomous driving. In addition to light distribution capabilities that outperform Adaptive Front Lighting and Matrix Beam systems, pixel light systems provide the possibility of image projection directly onto the street. The underlying objective is to improve the driving experience, in any given scenario, in terms of safety, comfort and interaction for all road users. The focus of this work is to conduct a short survey on this state-of-the-art image projection functionality. A holistic research regarding the image projection functionality can be divided into three major categories: scenario selection, technological development and evaluation design. Consequently, the work presented in this paper is divided into three short studies. Section 1 provides a brief introduction to pixel light systems and a justification for the approach adopted for this study. Section 2 deals with the selection of scenarios (and driving maneuvers) where image projection can play a critical role. Section 3 discusses high power LED and LED array based prototypes that are currently under development. Section 4 demonstrates results from an experiment conducted to evaluate the illuminance of an image space projected using a pixel light system prototype developed at the Institute of Product Development (IPeG). Findings from this work can help to identify and advance future research work relating to: further development of pixel light systems, scenario planning, examination of optimal light sources, behavioral response studies etc.

  2. Fan-beam and cone-beam image reconstruction via filtering the backprojection image of differentiated projection data

    International Nuclear Information System (INIS)

    Zhuang Tingliang; Leng Shuai; Nett, Brian E; Chen Guanghong

    2004-01-01

    In this paper, a new image reconstruction scheme is presented based on Tuy's cone-beam inversion scheme and its fan-beam counterpart. It is demonstrated that Tuy's inversion scheme may be used to derive a new framework for fan-beam and cone-beam image reconstruction. In this new framework, images are reconstructed via filtering the backprojection image of differentiated projection data. The new framework is mathematically exact and is applicable to a general source trajectory provided the Tuy data sufficiency condition is satisfied. By choosing a piece-wise constant function for one of the components in the factorized weighting function, the filtering kernel is one dimensional, viz. the filtering process is along a straight line. Thus, the derived image reconstruction algorithm is mathematically exact and efficient. In the cone-beam case, the derived reconstruction algorithm is applicable to a large class of source trajectories where the pi-lines or the generalized pi-lines exist. In addition, the new reconstruction scheme survives the super-short scan mode in both the fan-beam and cone-beam cases provided the data are not transversely truncated. Numerical simulations were conducted to validate the new reconstruction scheme for the fan-beam case

  3. Block matching sparsity regularization-based image reconstruction for incomplete projection data in computed tomography

    Science.gov (United States)

    Cai, Ailong; Li, Lei; Zheng, Zhizhong; Zhang, Hanming; Wang, Linyuan; Hu, Guoen; Yan, Bin

    2018-02-01

    In medical imaging many conventional regularization methods, such as total variation or total generalized variation, impose strong prior assumptions which can only account for very limited classes of images. A more reasonable sparse representation frame for images is still badly needed. Visually understandable images contain meaningful patterns, and combinations or collections of these patterns can be utilized to form some sparse and redundant representations which promise to facilitate image reconstructions. In this work, we propose and study block matching sparsity regularization (BMSR) and devise an optimization program using BMSR for computed tomography (CT) image reconstruction for an incomplete projection set. The program is built as a constrained optimization, minimizing the L1-norm of the coefficients of the image in the transformed domain subject to data observation and positivity of the image itself. To solve the program efficiently, a practical method based on the proximal point algorithm is developed and analyzed. In order to accelerate the convergence rate, a practical strategy for tuning the BMSR parameter is proposed and applied. The experimental results for various settings, including real CT scanning, have verified the proposed reconstruction method showing promising capabilities over conventional regularization.

  4. Minimizing image noise in on-board CT reconstruction using both kilovoltage and megavoltage beam projections

    International Nuclear Information System (INIS)

    Zhang Junan; Yin Fangfang

    2007-01-01

    We studied a recently proposed aggregated CT reconstruction technique which combines the complementary advantages of kilovoltage (kV) and megavoltage (MV) x-ray imaging. Various phantoms were imaged to study the effects of beam orientations and geometry of the imaging object on image quality of reconstructed CT. It was shown that the quality of aggregated CT was correlated with both kV and MV beam orientations and the degree of this correlation depended upon the geometry of the imaging object. The results indicated that the optimal orientations were those when kV beams pass through the thinner portion and MV beams pass through the thicker portion of the imaging object. A special preprocessing procedure was also developed to perform contrast conversions between kV and MV information prior to image reconstruction. The performance of two reconstruction methods, one filtered backprojection method and one iterative method, were compared. The effects of projection number, beam truncation, and contrast conversion on the CT image quality were investigated

  5. Learning binary code via PCA of angle projection for image retrieval

    Science.gov (United States)

    Yang, Fumeng; Ye, Zhiqiang; Wei, Xueqi; Wu, Congzhong

    2018-01-01

    With benefits of low storage costs and high query speeds, binary code representation methods are widely researched for efficiently retrieving large-scale data. In image hashing method, learning hashing function to embed highdimensions feature to Hamming space is a key step for accuracy retrieval. Principal component analysis (PCA) technical is widely used in compact hashing methods, and most these hashing methods adopt PCA projection functions to project the original data into several dimensions of real values, and then each of these projected dimensions is quantized into one bit by thresholding. The variances of different projected dimensions are different, and with real-valued projection produced more quantization error. To avoid the real-valued projection with large quantization error, in this paper we proposed to use Cosine similarity projection for each dimensions, the angle projection can keep the original structure and more compact with the Cosine-valued. We used our method combined the ITQ hashing algorithm, and the extensive experiments on the public CIFAR-10 and Caltech-256 datasets validate the effectiveness of the proposed method.

  6. A method for volumetric imaging in radiotherapy using single x-ray projection

    International Nuclear Information System (INIS)

    Xu, Yuan; Yan, Hao; Ouyang, Luo; Wang, Jing; Jiang, Steve B.; Jia, Xun; Zhou, Linghong; Cervino, Laura

    2015-01-01

    Purpose: It is an intriguing problem to generate an instantaneous volumetric image based on the corresponding x-ray projection. The purpose of this study is to develop a new method to achieve this goal via a sparse learning approach. Methods: To extract motion information hidden in projection images, the authors partitioned a projection image into small rectangular patches. The authors utilized a sparse learning method to automatically select patches that have a high correlation with principal component analysis (PCA) coefficients of a lung motion model. A model that maps the patch intensity to the PCA coefficients was built along with the patch selection process. Based on this model, a measured projection can be used to predict the PCA coefficients, which are then further used to generate a motion vector field and hence a volumetric image. The authors have also proposed an intensity baseline correction method based on the partitioned projection, in which the first and the second moments of pixel intensities at a patch in a simulated projection image are matched with those in a measured one via a linear transformation. The proposed method has been validated in both simulated data and real phantom data. Results: The algorithm is able to identify patches that contain relevant motion information such as the diaphragm region. It is found that an intensity baseline correction step is important to remove the systematic error in the motion prediction. For the simulation case, the sparse learning model reduced the prediction error for the first PCA coefficient to 5%, compared to the 10% error when sparse learning was not used, and the 95th percentile error for the predicted motion vector was reduced from 2.40 to 0.92 mm. In the phantom case with a regular tumor motion, the predicted tumor trajectory was successfully reconstructed with a 0.82 mm error for tumor center localization compared to a 1.66 mm error without using the sparse learning method. When the tumor motion

  7. Calibration, Projection, and Final Image Products of MESSENGER's Mercury Dual Imaging System

    Science.gov (United States)

    Denevi, Brett W.; Chabot, Nancy L.; Murchie, Scott L.; Becker, Kris J.; Blewett, David T.; Domingue, Deborah L.; Ernst, Carolyn M.; Hash, Christopher D.; Hawkins, S. Edward; Keller, Mary R.; Laslo, Nori R.; Nair, Hari; Robinson, Mark S.; Seelos, Frank P.; Stephens, Grant K.; Turner, F. Scott; Solomon, Sean C.

    2018-02-01

    We present an overview of the operations, calibration, geodetic control, photometric standardization, and processing of images from the Mercury Dual Imaging System (MDIS) acquired during the orbital phase of the MESSENGER spacecraft's mission at Mercury (18 March 2011-30 April 2015). We also provide a summary of all of the MDIS products that are available in NASA's Planetary Data System (PDS). Updates to the radiometric calibration included slight modification of the frame-transfer smear correction, updates to the flat fields of some wide-angle camera (WAC) filters, a new model for the temperature dependence of narrow-angle camera (NAC) and WAC sensitivity, and an empirical correction for temporal changes in WAC responsivity. Further, efforts to characterize scattered light in the WAC system are described, along with a mosaic-dependent correction for scattered light that was derived for two regional mosaics. Updates to the geometric calibration focused on the focal lengths and distortions of the NAC and all WAC filters, NAC-WAC alignment, and calibration of the MDIS pivot angle and base. Additionally, two control networks were derived so that the majority of MDIS images can be co-registered with sub-pixel accuracy; the larger of the two control networks was also used to create a global digital elevation model. Finally, we describe the image processing and photometric standardization parameters used in the creation of the MDIS advanced products in the PDS, which include seven large-scale mosaics, numerous targeted local mosaics, and a set of digital elevation models ranging in scale from local to global.

  8. Detecting Buried Archaeological Remains by the Use of Geophysical Data Processing with 'Diffusion Maps' Methodology

    Science.gov (United States)

    Eppelbaum, Lev

    2015-04-01

    approximation. Then, we can present A1 as A2 + D2, etc. So, if S - Signal, A - Approximation, D - Details, then S = A1 + D1 = A2 + D2 + D1 = A3 + D3 + D2 + D1. Wavelet packet transform is applied to both low pass results (approximations) and high pass results (Details). For analyzing the geophysical data, we used a technique based on the algorithm to characterize a geophysical image by a limited number of parameters (Eppelbaum et al., 2012). This set of parameters serves as a signature of the image and is utilized for discrimination of images (a) containing AT from the images (b) non-containing AT (let will designate these images as N). The constructed algorithm consists of the following main phases: (a) collection of the database, (b) characterization of geophysical images, (c) and dimensionality reduction. Then, each image is characterized by the histogram of the coherency directions (Alperovich et al., 2013). As a result of the previous steps we obtain two sets: containing AT and N of the signatures vectors for geophysical images. The obtained 3D set of the data representatives can be used as a reference set for the classification of newly arriving geophysical data. The obtained data sets are reduced by embedding features vectors into the 3D Euclidean space using the so-called diffusion map. This map enables to reveal the internal structure of the datasets AT and N and to distinctly separate them. For this, a matrix of the diffusion distances for the combined feature matrix F = FN ∴ FC of size 60 x C is constructed (Coifman and Lafon, 2006; Averbuch et al., 2010). Then, each row of the matrices FN and FC is projected onto three first eigenvectors of the matrix D(F ). As a result, each data curve is represented by a 3D point in the Euclidean space formed by eigenvectors of D(F ). The Euclidean distances between these 3D points reflect the similarity of the data curves. The scattered projections of the data curves onto the diffusion eigenvectors will be composed. Finally we

  9. Non-invasive Geophysical Surveys in Search of the Roman Temple of Augustus Under the Cathedral of Tarragona (Catalonia, Spain): A Case Study

    Science.gov (United States)

    Casas, Albert; Cosentino, Pietro L.; Fiandaca, Gianluca; Himi, Mahjoub; Macias, Josep M.; Martorana, Raffaele; Muñoz, Andreu; Rivero, Lluís; Sala, Roger; Teixell, Imma

    2018-04-01

    An integrated geophysical survey has been conducted at the Tarragona's Cathedral (Catalonia, NE Spain) with the aim to confirm the potential occurrence of archaeological remains of the Roman Temple dedicated to the Emperor Augustus. Many hypotheses have been proposed about its possible location, the last ones regarding the inner part of the Cathedral, which is one of the most renowned temples of Spain (twelfth century) evolving from Romanesque to Gothic styles. A geophysical project including electrical resistivity tomography (ERT) and ground probing radar (GPR) was planned over 1 year considering the administrative and logistic difficulties of such a project inside a cathedral of religious veneration. Finally, both ERT and GPR have been conducted during a week of intensive overnight surveys that provided detailed information on subsurface existing structures. The ERT method has been applied using different techniques and arrays, ranging from standard Wenner-Schlumberger 2D sections to full 3D electrical imaging with the advanced Maximum Yield Grid array. Electrical resistivity data were recorded extensively, making available many thousands of apparent resistivity data to obtain a complete 3D image after a full inversion. In conclusion, some significant buried structures have been revealed providing conclusive information for archaeologists. GPR results provided additional information about shallowest structures. The geophysical results were clear enough to persuade religious authorities and archaeologists to conduct selected excavations in the most promising areas that confirmed the interpretation of geophysical data. In conclusion, the significant buried structures revealed by geophysical methods under the cathedral were confirmed by archaeological digging as the basement of the impressive Roman Temple that headed the Provincial Forum of Tarraco, seat of the Concilium of Hispania Citerior Province.

  10. Development of an image reconstruction algorithm for a few number of projection data

    International Nuclear Information System (INIS)

    Vieira, Wilson S.; Brandao, Luiz E.; Braz, Delson

    2007-01-01

    An image reconstruction algorithm was developed for specific cases of radiotracer applications in industry (rotating cylindrical mixers), involving a very few number of projection data. The algorithm was planned for imaging radioactive isotope distributions around the center of circular planes. The method consists of adapting the original expectation maximization algorithm (EM) to solve the ill-posed emission tomography inverse problem in order to reconstruct transversal 2D images of an object with only four projections. To achieve this aim, counts of photons emitted by selected radioactive sources in the plane, after they had been simulated using the commercial software MICROSHIELD 5.05, constitutes the projections and a computational code (SPECTEM) was developed to generate activity vectors or images related to those sources. SPECTEM is flexible to support simultaneous changes of the detectors's geometry, the medium under investigation and the properties of the gamma radiation. As a consequence of the code had been followed correctly the proposed method, good results were obtained and they encouraged us to continue the next step of the research: the validation of SPECTEM utilizing experimental data to check its real performance. We aim this code will improve considerably radiotracer methodology, making easier the diagnosis of fails in industrial processes. (author)

  11. Development of an image reconstruction algorithm for a few number of projection data

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Wilson S.; Brandao, Luiz E. [Instituto de Engenharia Nuclear (IEN-CNEN/RJ), Rio de Janeiro , RJ (Brazil)]. E-mails: wilson@ien.gov.br; brandao@ien.gov.br; Braz, Delson [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programa de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear]. E-mail: delson@mailhost.lin.ufrj.br

    2007-07-01

    An image reconstruction algorithm was developed for specific cases of radiotracer applications in industry (rotating cylindrical mixers), involving a very few number of projection data. The algorithm was planned for imaging radioactive isotope distributions around the center of circular planes. The method consists of adapting the original expectation maximization algorithm (EM) to solve the ill-posed emission tomography inverse problem in order to reconstruct transversal 2D images of an object with only four projections. To achieve this aim, counts of photons emitted by selected radioactive sources in the plane, after they had been simulated using the commercial software MICROSHIELD 5.05, constitutes the projections and a computational code (SPECTEM) was developed to generate activity vectors or images related to those sources. SPECTEM is flexible to support simultaneous changes of the detectors's geometry, the medium under investigation and the properties of the gamma radiation. As a consequence of the code had been followed correctly the proposed method, good results were obtained and they encouraged us to continue the next step of the research: the validation of SPECTEM utilizing experimental data to check its real performance. We aim this code will improve considerably radiotracer methodology, making easier the diagnosis of fails in industrial processes. (author)

  12. Project Blue: Optical Coronagraphic Imaging Search for Terrestrial-class Exoplanets in Alpha Centauri

    Science.gov (United States)

    Morse, Jon; Project Blue team

    2018-01-01

    Project Blue is a coronagraphic imaging space telescope mission designed to search for habitable worlds orbiting the nearest Sun-like stars in the Alpha Centauri system. With a 45-50 cm baseline primary mirror size, Project Blue will perform a reconnaissance of the habitable zones of Alpha Centauri A and B in blue light and one or two longer wavelength bands to determine the hue of any planets discovered. Light passing through the off-axis telescope feeds into a coronagraphic instrument that forms the heart of the mission. Various coronagraph designs are being considered, such as phase induced amplitude apodization (PIAA), vector vortex, etc. Differential orbital image processing techniques will be employed to analyze the data for faint planets embedded in the residual glare of the parent star. Project Blue will advance our knowledge about the presence or absence of terrestrial-class exoplanets in the habitable zones and measure the brightness of zodiacal dust around each star, which will aid future missions in planning their observational surveys of exoplanets. It also provides on-orbit demonstration of high-contrast coronagraphic imaging technologies and techniques that will be useful for planning and implementing future space missions by NASA and other space agencies. We present an overview of the science goals, mission concept and development schedule. As part of our cooperative agreement with NASA, the Project Blue team intends to make the data available in a publicly accessible archive.

  13. Overview of image reconstruction

    International Nuclear Information System (INIS)

    Marr, R.B.

    1980-04-01

    Image reconstruction (or computerized tomography, etc.) is any process whereby a function, f, on R/sup n/ is estimated from empirical data pertaining to its integrals, ∫f(x) dx, for some collection of hyperplanes of dimension k < n. The paper begins with background information on how image reconstruction problems have arisen in practice, and describes some of the application areas of past or current interest; these include radioastronomy, optics, radiology and nuclear medicine, electron microscopy, acoustical imaging, geophysical tomography, nondestructive testing, and NMR zeugmatography. Then the various reconstruction algorithms are discussed in five classes: summation, or simple back-projection; convolution, or filtered back-projection; Fourier and other functional transforms; orthogonal function series expansion; and iterative methods. Certain more technical mathematical aspects of image reconstruction are considered from the standpoint of uniqueness, consistency, and stability of solution. The paper concludes by presenting certain open problems. 73 references

  14. A study on projection angles for an optimal image of PNS water's view on children

    International Nuclear Information System (INIS)

    Son, Sang Hyuk; Song, Young Geun; Kim, Sung Kyu; Hong, Sang Woo; Kim, Je Bong

    2007-01-01

    This study is to calculate the proper angle for the optimal image of PNS Water's view on children, comparing and analyzing the PNS Water's projection angles between children and adults at every age. This study randomly selected 50 patients who visited the Medical Center from January to May in 2005, and examined the incidence path of central ray, taking a PNS Water's and skull trans-Lat. view in Water's filming position while attaching a lead ball mark on the Orbit, EAM, and acanthion of the patient's skull. And then, we calculated the incidence angles (angle A) of the line connected from OML and the petrous ridge to the inferior margin of maxilla on general (random) patient's skull image, following the incidence path of central ray. Finally, we analyzed two pieces of the graphs at ages, developing out the patient's ideal images at PNS Water's filming position taken by a digital camera, and calculating the angle (angle B) between OML and IP(Image Plate). The angle between OML and IP is about 43 .deg. in 4-years-old children, which is higher than 37 .deg. as age increases the angle decreases, it goes to 37 .deg. around 30 years of age. That is similar result to maxillary growth period. We can get better quality of Water's image for children when taking the PNS Water's view if we change the projection angles, considering maxillary growth for patients in every age stage

  15. 3D fingerprint imaging system based on full-field fringe projection profilometry

    Science.gov (United States)

    Huang, Shujun; Zhang, Zonghua; Zhao, Yan; Dai, Jie; Chen, Chao; Xu, Yongjia; Zhang, E.; Xie, Lili

    2014-01-01

    As an unique, unchangeable and easily acquired biometrics, fingerprint has been widely studied in academics and applied in many fields over the years. The traditional fingerprint recognition methods are based on the obtained 2D feature of fingerprint. However, fingerprint is a 3D biological characteristic. The mapping from 3D to 2D loses 1D information and causes nonlinear distortion of the captured fingerprint. Therefore, it is becoming more and more important to obtain 3D fingerprint information for recognition. In this paper, a novel 3D fingerprint imaging system is presented based on fringe projection technique to obtain 3D features and the corresponding color texture information. A series of color sinusoidal fringe patterns with optimum three-fringe numbers are projected onto a finger surface. From another viewpoint, the fringe patterns are deformed by the finger surface and captured by a CCD camera. 3D shape data of the finger can be obtained from the captured fringe pattern images. This paper studies the prototype of the 3D fingerprint imaging system, including principle of 3D fingerprint acquisition, hardware design of the 3D imaging system, 3D calibration of the system, and software development. Some experiments are carried out by acquiring several 3D fingerprint data. The experimental results demonstrate the feasibility of the proposed 3D fingerprint imaging system.

  16. Image quality of microcalcifications in digital breast tomosynthesis: Effects of projection-view distributions

    OpenAIRE

    Lu, Yao; Chan, Heang-Ping; Wei, Jun; Goodsitt, Mitch; Carson, Paul L.; Hadjiiski, Lubomir; Schmitz, Andrea; Eberhard, Jeffrey W.; Claus, Bernhard E. H.

    2011-01-01

    Purpose: To analyze the effects of projection-view (PV) distribution on the contrast and spatial blurring of microcalcifications on the tomosynthesized slices (X-Y plane) and along the depth (Z) direction for the same radiation dose in digital breast tomosynthesis (DBT).Methods: A GE GEN2 prototype DBT system was used for acquisition of DBT scans. The system acquires PV images from 21 angles in 3° increments over a ±30° range. From these acquired PV images, the authors selected six subsets of...

  17. Imaging Local Polarization in Ferroelectric Thin Films by Coherent X-Ray Bragg Projection Ptychography

    Science.gov (United States)

    Hruszkewycz, S. O.; Highland, M. J.; Holt, M. V.; Kim, Dongjin; Folkman, C. M.; Thompson, Carol; Tripathi, A.; Stephenson, G. B.; Hong, Seungbum; Fuoss, P. H.

    2013-04-01

    We used x-ray Bragg projection ptychography (BPP) to map spatial variations of ferroelectric polarization in thin film PbTiO3, which exhibited a striped nanoscale domain pattern on a high-miscut (001) SrTiO3 substrate. By converting the reconstructed BPP phase image to picometer-scale ionic displacements in the polar unit cell, a quantitative polarization map was made that was consistent with other characterization. The spatial resolution of 5.7 nm demonstrated here establishes BPP as an important tool for nanoscale ferroelectric domain imaging, especially in complex environments accessible with hard x rays.

  18. Real-time volumetric image reconstruction and 3D tumor localization based on a single x-ray projection image for lung cancer radiotherapy.

    Science.gov (United States)

    Li, Ruijiang; Jia, Xun; Lewis, John H; Gu, Xuejun; Folkerts, Michael; Men, Chunhua; Jiang, Steve B

    2010-06-01

    To develop an algorithm for real-time volumetric image reconstruction and 3D tumor localization based on a single x-ray projection image for lung cancer radiotherapy. Given a set of volumetric images of a patient at N breathing phases as the training data, deformable image registration was performed between a reference phase and the other N-1 phases, resulting in N-1 deformation vector fields (DVFs). These DVFs can be represented efficiently by a few eigenvectors and coefficients obtained from principal component analysis (PCA). By varying the PCA coefficients, new DVFs can be generated, which, when applied on the reference image, lead to new volumetric images. A volumetric image can then be reconstructed from a single projection image by optimizing the PCA coefficients such that its computed projection matches the measured one. The 3D location of the tumor can be derived by applying the inverted DVF on its position in the reference image. The algorithm was implemented on graphics processing units (GPUs) to achieve real-time efficiency. The training data were generated using a realistic and dynamic mathematical phantom with ten breathing phases. The testing data were 360 cone beam projections corresponding to one gantry rotation, simulated using the same phantom with a 50% increase in breathing amplitude. The average relative image intensity error of the reconstructed volumetric images is 6.9% +/- 2.4%. The average 3D tumor localization error is 0.8 +/- 0.5 mm. On an NVIDIA Tesla C1060 GPU card, the average computation time for reconstructing a volumetric image from each projection is 0.24 s (range: 0.17 and 0.35 s). The authors have shown the feasibility of reconstructing volumetric images and localizing tumor positions in 3D in near real-time from a single x-ray image.

  19. Neural network CT image reconstruction method for small amount of projection data

    CERN Document Server

    Ma, X F; Takeda, T

    2000-01-01

    This paper presents a new method for two-dimensional image reconstruction by using a multi-layer neural network. Though a conventionally used object function of such a neural network is composed of a sum of squared errors of the output data, we define an object function composed of a sum of squared residuals of an integral equation. By employing an appropriate numerical line integral for this integral equation, we can construct a neural network which can be used for CT image reconstruction for cases with small amount of projection data. We applied this method to some model problems and obtained satisfactory results. This method is especially useful for analyses of laboratory experiments or field observations where only a small amount of projection data is available in comparison with the well-developed medical applications.

  20. Neural network CT image reconstruction method for small amount of projection data

    International Nuclear Information System (INIS)

    Ma, X.F.; Fukuhara, M.; Takeda, T.

    2000-01-01

    This paper presents a new method for two-dimensional image reconstruction by using a multi-layer neural network. Though a conventionally used object function of such a neural network is composed of a sum of squared errors of the output data, we define an object function composed of a sum of squared residuals of an integral equation. By employing an appropriate numerical line integral for this integral equation, we can construct a neural network which can be used for CT image reconstruction for cases with small amount of projection data. We applied this method to some model problems and obtained satisfactory results. This method is especially useful for analyses of laboratory experiments or field observations where only a small amount of projection data is available in comparison with the well-developed medical applications

  1. Archaeological Geophysics in Israel: Past, Present and Future

    Science.gov (United States)

    Eppelbaum, L. V.

    2009-04-01

    et al., 1999; Reeder et al., 2004; Reinhardt et al., 2006; Reich et al., 2003; Ron et al., 2003; Segal et al., 2003; Sternberg and Lass, 2007; Sternberg et al., 1999; Verri et al., 2004; Weiner et al., 1993; Weinstein-Evron et al., 1991, 2003; Weiss et al., 2007; Witten et al., 1994), and (3) future [2010 -]. The past stage with several archaeoseismic reviews and very limited application of geophysical methods was replaced by the present stage with the violent employment of numerous geophysical techniques (first of all, high-precise magnetic survey and GPR). It is supposed that the future stage will be characterized by extensive development of multidiscipline physical-archaeological databases (Eppelbaum et al., 2009b), utilization of supercomputers for 4D monitoring and ancient sites reconstruction (Foster et al., 2001; Pelfer et al., 2004) as well as wide application of geophysical surveys using remote operated vehicles at low altitudes (Eppelbaum, 2008a). REFERENCES Batey, R.A., 1987. Subsurface Interface Radar at Sepphoris, Israel 1985. Journal of Field Archaeology, 14 (1), 1-8. Bauman, P., Parker, D., Coren, A., Freund, R., and Reeder, P., 2005. Archaeological Reconnaissance at Tel Yavne, Israel: 2-D Electrical Imaging and Low Altitude Aerial Photography. CSEG Recorder, No. 6, 28-33. Ben-Dor, E., Portugali, J., Kochavi, M., Shimoni, M., and Vinitzky, L., 1999. Airborne thermal video radiometry and excavation planning at Tel Leviah, Golan Heights, Israel. Journal of Field Archaeology, 26 (2), 117-127. Ben-Menahem, A., 1979. Earthquake catalogue for the Middle East (92 B.C. - 1980 A.D.). Bollettino di Geofisica Teorica ed Applicata, 21 (84), 245-310. Ben-Yosef, E., Tauxe, L., Ronb, H., Agnon, A., Avner, U., Najjar, M., and Levy, T.E., 2008. A new approach for geomagnetic archaeointensity research: insights on ancient metallurgy in the Southern Levant. Journal of Archaeological Science, 25, 2863-2879. Berkovitch, A.L., Eppelbaum, L.V., and Basson, U., 2000

  2. Kinematic Measurement of Knee Prosthesis from Single-Plane Projection Images

    Science.gov (United States)

    Hirokawa, Shunji; Ariyoshi, Shogo; Takahashi, Kenji; Maruyama, Koichi

    In this paper, the measurement of 3D motion from 2D perspective projections of knee prosthesis is described. The technique reported by Banks and Hodge was further developed in this study. The estimation was performed in two steps. The first-step estimation was performed on the assumption of orthogonal projection. Then, the second-step estimation was subsequently carried out based upon the perspective projection to accomplish more accurate estimation. The simulation results have demonstrated that the technique archived sufficient accuracies of position/orientation estimation for prosthetic kinematics. Then we applied our algorithm to the CCD images, thereby examining the influences of various artifacts, possibly incorporated through an imaging process, on the estimation accuracies. We found that accuracies in the experiment were influenced mainly by the geometric discrepancies between the prosthesis component and computer generated model and by the spacial inconsistencies between the coordinate axes of the positioner and that of the computer model. However, we verified that our algorithm could achieve proper and consistent estimation even for the CCD images.

  3. Preliminary evaluation of alterant geophysical tomography in welded tuff

    International Nuclear Information System (INIS)

    Ramirez, A.L.; Daily, W.D.

    1985-01-01

    The ability of alterant geophysical tomography to delineate flow paths in a welded tuff rock mass has been preliminarily evaluated based on the results of a field experiment. Electromagnetic measurements were made before, during and after a water-based, dye tracer flowed through the rock mass. Alterant geophysical tomographs were generated and compared with independent evidence - borescope logs, neutron logs and dyed rock samples. Anomalies present in the tomograph match the location and orientation of fractures mapped with a borescope. The location of tracer-stained fractures coincides with the location of some image anomalies; other geophysical anomalies exist where tracer-stained fractures were not observed, perhaps due to poor core recovery. Additional drilling to locate stained flow paths and other experiments are planned so that the applicability of the technique can be further evaluated

  4. Geophysical mapping of complex glaciogenic large-scale structures

    DEFF Research Database (Denmark)

    Høyer, Anne-Sophie

    2013-01-01

    This thesis presents the main results of a four year PhD study concerning the use of geophysical data in geological mapping. The study is related to the Geocenter project, “KOMPLEKS”, which focuses on the mapping of complex, large-scale geological structures. The study area is approximately 100 km2...... data types and co-interpret them in order to improve our geological understanding. However, in order to perform this successfully, methodological considerations are necessary. For instance, a structure indicated by a reflection in the seismic data is not always apparent in the resistivity data...... information) can be collected. The geophysical data are used together with geological analyses from boreholes and pits to interpret the geological history of the hill-island. The geophysical data reveal that the glaciotectonic structures truncate at the surface. The directions of the structures were mapped...

  5. Integrated geophysical surveys for searching of podiform chromite in Albania

    Energy Technology Data Exchange (ETDEWEB)

    Kospiri, Aleksander; Zajmi, Asim [Geophysical and Geochemical Center, Tirana (Albania)

    1995-12-31

    The purpose of this paper is to describe the application of geophysical methods to the search for chromite in Albania. Albania is well known for its chromite resources and ranks third amongst world producers of high-quality chromite. The ultramafic massif of Bulqiza, is the most important chromite bearing one. Surveying a surface of about 120 square kilometers (30% of massifs area) in that massif with integrated geophysical methods a considerable number of targets has been discovered, from which some are already objects under mine activity. In the integrated methods for chromite exploration in Bulqiza ultramafic massif are included: geological, gravity, magnetic and electrical mapping of the scale 1:2000 with survey grids 40x20m, 20x5m. Based on the interpretations of geophysical exploration were projected drilling which led to the discovery of some big ore deposits. (author). 12 refs., 3 figs

  6. THE USE OF PUBLIC RELATIONS IN PROJECTING AN ORGANIZATION'S POSITIVE IMAGE

    Directory of Open Access Journals (Sweden)

    Ioana Olariu

    2017-07-01

    Full Text Available This article is a theoretical approach on the importance of using public relations in helping an organization to project a positive image. The study of the impact information has on the image of organisations seems to be an interesting research topic. Practice has proved that the image of institutions has a patrimonial value and it is sometimes essential in raising their credibility. It can be said that an image is defined as the representation of certain attitudes, opinions or prejudices concerning a person, a group of persons or the public opinion concerning an institution. In other words, an image is the opinion of a person, of a group of persons or of the public opinion regarding that institution. All specialists agree that a negative image affects, sometimes to an incredible extent, the success of an institution. In the contemporary age, we cannot speak about public opinion without taking into consideration the mass media as a main agent in transmitting the information to the public, with unlimited possibilities of influencing or forming it. The plan for the PR department starts with its own declaration of principles, which describes its roles and contribution to the organisation.

  7. Geophysics comes of age in oil sands development

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, P. [WorleyParsons Komex, Calgary, AB (Canada); Birch, R.; Parker, D.; Andrews, B. [Calgary Univ., AB (Canada). Dept. of Geology and Geophysics

    2008-07-01

    This paper discussed geophysical techniques developed for oil sands exploration and production applications in Alberta's oil sands region. Geophysical methods are playing an important role in mine planning, tailings containment, water supply, and land reclamation activities. Geophysics techniques are used to estimate the volume of muskeg that needs to be stripped and stored for future reclamation activities as well as to site muskeg piles and delineate the thickness of clay Clearwater formations overlying Cretaceous oil-bearing sands. 2-D electrical resistivity mapping is used to map river-connected deep bedrock Pleistocene paleovalleys in the region. Geophysical studies are also used to investigate the interiors of dikes and berms as well as to monitor salt migration within tailings piles. Sonic and density logs are used to create synthetic seismograms for mapping the Devonian surface in the region. The new applications included the calculation of bitumen saturation from surface sands and shales; muskeg thickness mapping; and non-intrusive monitoring of leachate plumes. Geophysical techniques included 2-D electrical resistivity imaging; transient electromagnetic (EM) technologies; ground penetrating radar; and high-resolution seismic reflections. Polarization, surface nuclear magnetic resonance and push-probe sensing techniques were also discussed. Techniques were discussed in relation to Alberta's Athabasca oil sands deposits. 4 refs.

  8. Geophysical background and as-built target characteristics

    International Nuclear Information System (INIS)

    Allen, J.W.

    1994-09-01

    The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) has provided a facility for DOE, other Government agencies, and the private sector to evaluate and document the utility of specific geophysical measurement techniques for detecting and defining cultural and environmental targets. This facility is the Rabbit Valley Geophysics Performance Evaluation Range (GPER). Geophysical surveys prior to the fiscal year (FY) 1994 construction of new test cells showed the primary test area to be relatively homogeneous and free from natural or man-made artifacts, which would generate spurious responses in performance evaluation data. Construction of nine new cell areas in Rabbit Valley was completed in June 1994 and resulted in the emplacement of approximately 150 discrete targets selected for their physical and electrical properties. These targets and their geophysical environment provide a broad range of performance evaluation parameters from ''very easy to detect'' to ''challenging to the most advanced systems.'' Use of nonintrusive investigative techniques represents a significant improvement over intrusive characterization methods, such as drilling or excavation, because there is no danger of exposing personnel to possible hazardous materials and no risk of releasing or spreading contamination through the characterization activity. Nonintrusive geophysical techniques provide the ability to infer near-surface structure and waste characteristics from measurements of physical properties associated with those targets

  9. Factors affecting the effectiveness of a projection dephaser in 2D gradient-echo imaging

    International Nuclear Information System (INIS)

    Bakker, Chris J G; Peters, Nicky H G M; Vincken, Koen L; Bom, Martijn van der; Seppenwoolde, Jan-Henry

    2007-01-01

    Projection dephasers are often used for background suppression and dynamic range improvement in thick-slab 2D imaging in order to promote the visibility of subslice structures, e.g., blood vessels and interventional devices. In this study, we explored the factors that govern the effectiveness of a projection dephaser by simulations and phantom experiments. This was done for the ideal case of a single subslice hyper- or hypointensity against a uniform background in the absence of susceptibility effects. Simulations and experiments revealed a pronounced influence of the slice profile, the nominal flip angle and the TE and TR of the acquisition, the size, intraslice position and MR properties of the subslice structure, and T 1 of the background. The complexity of the ideal case points to the necessity of additional explorations when considering the use of projection dephasers under less ideal conditions, e.g., in the presence of tissue heterogeneities and susceptibility gradients

  10. Neural network algorithm for image reconstruction using the grid friendly projections

    International Nuclear Information System (INIS)

    Cierniak, R.

    2011-01-01

    Full text: The presented paper describes a development of original approach to the reconstruction problem using a recurrent neural network. Particularly, the 'grid-friendly' angles of performed projections are selected according to the discrete Radon transform (DRT) concept to decrease the number of projections required. The methodology of our approach is consistent with analytical reconstruction algorithms. Reconstruction problem is reformulated in our approach to optimization problem. This problem is solved in present concept using method based on the maximum likelihood methodology. The reconstruction algorithm proposed in this work is consequently adapted for more practical discrete fan beam projections. Computer simulation results show that the neural network reconstruction algorithm designed to work in this way improves obtained results and outperforms conventional methods in reconstructed image quality. (author)

  11. The Ilac-Project Supporting Ancient Coin Classification by Means of Image Analysis

    Science.gov (United States)

    Kavelar, A.; Zambanini, S.; Kampel, M.; Vondrovec, K.; Siegl, K.

    2013-07-01

    This paper presents the ILAC project, which aims at the development of an automated image-based classification system for ancient Roman Republican coins. The benefits of such a system are manifold: operating at the suture between computer vision and numismatics, ILAC can reduce the day-to-day workload of numismatists by assisting them in classification tasks and providing a preselection of suitable coin classes. This is especially helpful for large coin hoard findings comprising several thousands of coins. Furthermore, this system could be implemented in an online platform for hobby numismatists, allowing them to access background information about their coin collection by simply uploading a photo of obverse and reverse for the coin of interest. ILAC explores different computer vision techniques and their combinations for the use of image-based coin recognition. Some of these methods, such as image matching, use the entire coin image in the classification process, while symbol or legend recognition exploit certain characteristics of the coin imagery. An overview of the methods explored so far and the respective experiments is given as well as an outlook on the next steps of the project.

  12. THE ILAC-PROJECT: SUPPORTING ANCIENT COIN CLASSIFICATION BY MEANS OF IMAGE ANALYSIS

    Directory of Open Access Journals (Sweden)

    A. Kavelar

    2013-07-01

    Full Text Available This paper presents the ILAC project, which aims at the development of an automated image-based classification system for ancient Roman Republican coins. The benefits of such a system are manifold: operating at the suture between computer vision and numismatics, ILAC can reduce the day-to-day workload of numismatists by assisting them in classification tasks and providing a preselection of suitable coin classes. This is especially helpful for large coin hoard findings comprising several thousands of coins. Furthermore, this system could be implemented in an online platform for hobby numismatists, allowing them to access background information about their coin collection by simply uploading a photo of obverse and reverse for the coin of interest. ILAC explores different computer vision techniques and their combinations for the use of image-based coin recognition. Some of these methods, such as image matching, use the entire coin image in the classification process, while symbol or legend recognition exploit certain characteristics of the coin imagery. An overview of the methods explored so far and the respective experiments is given as well as an outlook on the next steps of the project.

  13. Digital Underground (Shh. It's really Applied Geophysics!)

    Science.gov (United States)

    McAdoo, B. G.

    2003-12-01

    Digital Underground (Geology/Physics 241) at Vassar College is an applied geophysics course designed for a liberal arts curriculum, and has nothing to do with Shock G and Tupac Shakur. Applied geophysics courses have a history of using geophysical methods on environmental contamination-type applications (underground storage tanks, leach fields, etc.). Inspired in large part by the Keck Geology Consortium project run by Franklin and Marshall College geophysicist (Robert Sternberg) and archaeologist (James Delle) in an old slave village in Jamaica in 1999, this class examines the history of slavery in New York's Hudson Valley region by way of its forgotten African-American graveyards. This multidisciplinary approach to an issue draws students from across the curriculum- we have had our compliments of geologists and physicists, along with students from sociology, environmental studies, history, and Africana studies. The name of the class and content are designed to attract a non-traditional student of geophysics.- The project-based nature of the class appeals to student yearning for an out-of-classroom experience. The uncontrolled nature of the class demonstrates the complications that occur in real-word situations. The class has in the past broken itself into two teams- a surveying team and an archival research team. Archival research is done (usually by the social scientists in the class) to add a human dimension to the geophysical. The surveying equipment used in delineating these forgotten graveyards includes a Total Station surveyor, an electrical resistivity meter, a magnetometer, and a ground penetrating radar. All students must have a rudimentary understanding of the physics behind the equipment (to the level of where they can explain it to the general public), and the methods used by those studying the archives. This is a project-based class, where the instructor acts as a project manager, and the students make the decisions regarding the survey itself. Every

  14. Basic elements of nuclear geophysics

    International Nuclear Information System (INIS)

    Nordemann, D.J.R.; Pereira, E.B.

    1984-01-01

    Nuclear Geophysics applies the nuclear radiation detection methodology to the geosciences, specially to study the dynamical processes of the lithosphere, the hydrosphere and the atmosphere as well as some aspects of planetology and astrophysics. Here the main methods are described: alpha-ray and gamma-ray spectrometry, the interaction of alpha and gamma radiation with matter and the detectors used (grid chambers, surface barrier silicon detector for alpha radiation; and sodium iodide thallium activated phosphors, hyperpure and lithium drifted germanium semiconductor detectors for gamma radiation). The principal applications of Nuclear Geophysics are given as examples to ilustrate the use of the methods described. (AUthor) [pt

  15. Breast EIT using a new projected image reconstruction method with multi-frequency measurements.

    Science.gov (United States)

    Lee, Eunjung; Ts, Munkh-Erdene; Seo, Jin Keun; Woo, Eung Je

    2012-05-01

    We propose a new method to produce admittivity images of the breast for the diagnosis of breast cancer using electrical impedance tomography(EIT). Considering the anatomical structure of the breast, we designed an electrode configuration where current-injection and voltage-sensing electrodes are separated in such a way that internal current pathways are approximately along the tangential direction of an array of voltage-sensing electrodes. Unlike conventional EIT imaging methods where the number of injected currents is maximized to increase the total amount of measured data, current is injected only twice between two pairs of current-injection electrodes attached along the circumferential side of the breast. For each current injection, the induced voltages are measured from the front surface of the breast using as many voltage-sensing electrodes as possible. Although this electrode configurational lows us to measure induced voltages only on the front surface of the breast,they are more sensitive to an anomaly inside the breast since such an injected current tends to produce a more uniform internal current density distribution. Furthermore, the sensitivity of a measured boundary voltage between two equipotential lines on the front surface of the breast is improved since those equipotential lines are perpendicular to the primary direction of internal current streamlines. One should note that this novel data collection method is different from those of other frontal plane techniques such as the x-ray projection and T-scan imaging methods because we do not get any data on the plane that is perpendicular to the current flow. To reconstruct admittivity images using two measured voltage data sets, a new projected image reconstruction algorithm is developed. Numerical simulations demonstrate the frequency-difference EIT imaging of the breast. The results show that the new method is promising to accurately detect and localize small anomalies inside the breast.

  16. Breast EIT using a new projected image reconstruction method with multi-frequency measurements

    International Nuclear Information System (INIS)

    Lee, Eunjung; Ts, Munkh-Erdene; Seo, Jin Keun; Woo, Eung Je

    2012-01-01

    We propose a new method to produce admittivity images of the breast for the diagnosis of breast cancer using electrical impedance tomography (EIT). Considering the anatomical structure of the breast, we designed an electrode configuration where current-injection and voltage-sensing electrodes are separated in such a way that internal current pathways are approximately along the tangential direction of an array of voltage-sensing electrodes. Unlike conventional EIT imaging methods where the number of injected currents is maximized to increase the total amount of measured data, current is injected only twice between two pairs of current-injection electrodes attached along the circumferential side of the breast. For each current injection, the induced voltages are measured from the front surface of the breast using as many voltage-sensing electrodes as possible. Although this electrode configuration allows us to measure induced voltages only on the front surface of the breast, they are more sensitive to an anomaly inside the breast since such an injected current tends to produce a more uniform internal current density distribution. Furthermore, the sensitivity of a measured boundary voltage between two equipotential lines on the front surface of the breast is improved since those equipotential lines are perpendicular to the primary direction of internal current streamlines. One should note that this novel data collection method is different from those of other frontal plane techniques such as the x-ray projection and T-scan imaging methods because we do not get any data on the plane that is perpendicular to the current flow. To reconstruct admittivity images using two measured voltage data sets, a new projected image reconstruction algorithm is developed. Numerical simulations demonstrate the frequency-difference EIT imaging of the breast. The results show that the new method is promising to accurately detect and localize small anomalies inside the breast. (paper)

  17. Geophysical data fusion for subsurface imaging

    International Nuclear Information System (INIS)

    Blohm, M.; Hatch, W.E.; Hoekstra, P.; Porter, D.W.

    1994-01-01

    Effective site characterization requires that many relevant geologic, hydrogeologic and biological properties of the subsurface be evaluated. A parameter that often directly influences chemical processes, ground water flow, contaminant transport, and biological activities is the lateral and vertical distribution of clays. The objective of the research an development under this contract is to improve non-invasive methods for detecting clay lenses. The percentage of clays in soils influences most physical properties that have an impact on environmental restoration and waste management. For example, the percentage of clays determine hydraulic permeability and the rate of contaminant migration, absorption of radioactive elements, and interaction with organic compounds. Therefore, improvements in non-invasive mapping of clays in the subsurface will result in better: characterization of contaminated sites, prediction of pathways of contaminant migration, assessment of risk of contaminants to public health if contaminants reach water supplies, design of remedial action and evaluation of alternative action

  18. History of geophysical studies at the Waste Isolation Pilot Plant (WIPP), southeastern New Mexico

    International Nuclear Information System (INIS)

    Borns, D.J.

    1997-01-01

    A variety of geophysical methods including the spectrum of seismic, electrical, electromagnetic and potential field techniques have used support characterization, monitoring and experimental studies at the Waste Isolation Pilot Plant (WIPP). The geophysical studies have provided significant understanding of the nature of site deformation, tectonics and stability. Geophysical methods have delineated possible brine reservoirs beneath the underground facility and have defined the disturbed rock zone that forms around underground excavations. The role of geophysics in the WIPP project has evolved with the project. The early uses were for site characterization to satisfy site selection criteria or factors. As the regulatory framework for WIPP grew since 1980, the geophysics program was focused on support of experimental and field programs such as Salado hydrogeology and underground room systems and excavations. In summary, the major types of issues that geophysical studies addressed for WIPP are: Issue 1: Site Characterization; Issue 2: Castile Brine Reservoirs; Issue 3: Rustler /Dewey Lake Hydrogeology; Issue 4: Salado Hydrogeology; and Issue 5: Excavation Effects. The nature of geophysics program for WIPP has been to support investigation rather than being the principal investigation itself. The geophysics program has been used to define conceptual models (e.g., the Disturbed Rock Zone-DRZ) or to test conceptual models (e.g., high transmissivity zones in the Rustler Formation). An effect of being a support program is that as new project priorities arose the funding for the geophysics program was limited and withdrawn. An outcome is that much of the geophysics survey information resides in contractor reports since final interpretation reports were not funded

  19. Digital breast tomosynthesis: computer-aided detection of clustered microcalcifications on planar projection images

    International Nuclear Information System (INIS)

    Samala, Ravi K; Chan, Heang-Ping; Lu, Yao; Hadjiiski, Lubomir M; Wei, Jun; Helvie, Mark A

    2014-01-01

    This paper describes a new approach to detect microcalcification clusters (MCs) in digital breast tomosynthesis (DBT) via its planar projection (PPJ) image. With IRB approval, two-view (cranio-caudal and mediolateral oblique views) DBTs of human subject breasts were obtained with a GE GEN2 prototype DBT system that acquires 21 projection angles spanning 60° in 3° increments. A data set of 307 volumes (154 human subjects) was divided by case into independent training (127 with MCs) and test sets (104 with MCs and 76 free of MCs). A simultaneous algebraic reconstruction technique with multiscale bilateral filtering (MSBF) regularization was used to enhance microcalcifications and suppress noise. During the MSBF regularized reconstruction, the DBT volume was separated into high frequency (HF) and low frequency components representing microcalcifications and larger structures. At the final iteration, maximum intensity projection was applied to the regularized HF volume to generate a PPJ image that contained MCs with increased contrast-to-noise ratio (CNR) and reduced search space. High CNR objects in the PPJ image were extracted and labeled as microcalcification candidates. Convolution neural network trained to recognize the image pattern of microcalcifications was used to classify the candidates into true calcifications and tissue structures and artifacts. The remaining microcalcification candidates were grouped into MCs by dynamic conditional clustering based on adaptive CNR threshold and radial distance criteria. False positive (FP) clusters were further reduced using the number of candidates in a cluster, CNR and size of microcalcification candidates. At 85% sensitivity an FP rate of 0.71 and 0.54 was achieved for view- and case-based sensitivity, respectively, compared to 2.16 and 0.85 achieved in DBT. The improvement was significant (p-value = 0.003) by JAFROC analysis. (paper)

  20. Marine geophysical data management and presentation system

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.

    ) of the National Institute of Oceanography, Goa, India. GPDMPS is designed for the computerized storage retrieval and presentation of marine geophysical data and information. For the systematic management of geophysical data and information, GPDMPS is subdivided...

  1. New K-edge-balanced contrast phantom for image quality assurance in projection radiography

    Science.gov (United States)

    Cresens, Marc; Schaetzing, Ralph

    2003-06-01

    X-ray-absorber step-wedge phantoms serve in projection radiography to assess a detection system's overall exposure-related signal-to-noise ratio performance and contrast response. Data derived from a phantom image, created by exposing a step-wedge onto the image receptor, are compared with predefined acceptance criteria during periodic image quality assurance (QA). For contrast-related measurements, in particular, the x-ray tube potential requires accurate setting and low ripple, since small deviations from the specified kVp, causing energy spectrum changes, lead to significant image signal variation at high contrast ratios. A K-edge-balanced, rare-earth-metal contrast phantom can generate signals that are significantly more robust to the spectral variability and instability of exposure equipment in the field. The image signals from a hafnium wedge, for example, are up to eight times less sensitive to spectral fluctuations than those of today"s copper phantoms for a 200:1 signal ratio. At 120 kVp (RQA 9), the hafnium phantom still preserves 70% of the subject contrast present at 75 kVp (RQA 5). A copper wedge preserves only 7% of its contrast over the same spectral range. Spectral simulations and measurements on prototype systems, as well as potential uses of this new class of phantoms (e.g., QA, single-shot exposure response characterization) are described.

  2. Respiratory compensation in projection imaging using a magnification and displacement model

    International Nuclear Information System (INIS)

    Crawford, C.R.; King, K.F.; Ritchie, C.J.; Godwin, J.D.

    1996-01-01

    Respiratory motion during the collection of computed tomography (CT) projections generates structured artifacts and a loss of resolution that can render the scans unusable. This motion is problematic in scans of those patients who cannot suspend respiration, such as the very young or incubated patients. In this paper, the authors present an algorithm that can be used to reduce motion artifacts in CT scans caused by respiration. An approximate model for the effect of respiration is that the object cross section under interrogation experiences time-varying magnification and displacement along two axes. Using this model an exact filtered backprojection algorithm is derived for the case of parallel projections. The result is extended to generate an approximate reconstruction formula for fan-beam projections. Computer simulations and scans of phantoms on a commercial CT scanner validate the new reconstruction algorithms for parallel and fan-beam projections. Significant reduction in respiratory artifacts is demonstrated clinically when the motion model is satisfied. The method can be applied to projection data used in CT single photon emission computed tomography (SPECT), positron emission tomography (PET), and magnetic resonance imaging (MRI)

  3. Geophysical logging for mineral exploration and development

    International Nuclear Information System (INIS)

    Plouffe, R.D.

    1981-01-01

    It is possible to retrieve from small-diameter holes geophysical data for qualitative interpretation in exploration and quantitative interpretation in the development of orebodies. The primary objectives in the exploration stage are to identify where, within a hole, economic minerals are, and to help in lithological interpretations. Other aspects, which are more quantitative, are the interpretation of downhole logs for parameters which can be used in surface geophysical methods (i.e. density for gravity surveys, acoustic velocities for seismic surveys, and magnetic susceptibility for airborne and ground magnetic surveys). Recent advances in equipment design, portability and durability have made downhole logging in exploration more inexpensive and reliable. This new equipment is being used to generate very precise quantitative results. This is especially true on uranium development projects. The interpretation of gamma logs for eU 3 O 8 values has finally become precise enough that they have begun to replace chemical values in reserve calculations. Another part of development data is density and equilibrium information, which, with today's technology, is being derived from downhole probing. In the years to come, the trends for many metals are toward neutron activation techniques, or in-situ assaying, and the use of multiple logs for better lithological and physical rock property determinations. (auth)

  4. Geophysical methods for monitoring soil stabilization processes

    Science.gov (United States)

    Saneiyan, Sina; Ntarlagiannis, Dimitrios; Werkema, D. Dale; Ustra, Andréa

    2018-01-01

    Soil stabilization involves methods used to turn unconsolidated and unstable soil into a stiffer, consolidated medium that could support engineered structures, alter permeability, change subsurface flow, or immobilize contamination through mineral precipitation. Among the variety of available methods carbonate precipitation is a very promising one, especially when it is being induced through common soil borne microbes (MICP - microbial induced carbonate precipitation). Such microbial mediated precipitation has the added benefit of not harming the environment as other methods can be environmentally detrimental. Carbonate precipitation, typically in the form of calcite, is a naturally occurring process that can be manipulated to deliver the expected soil strengthening results or permeability changes. This study investigates the ability of spectral induced polarization and shear-wave velocity for monitoring calcite driven soil strengthening processes. The results support the use of these geophysical methods as soil strengthening characterization and long term monitoring tools, which is a requirement for viable soil stabilization projects. Both tested methods are sensitive to calcite precipitation, with SIP offering additional information related to long term stability of precipitated carbonate. Carbonate precipitation has been confirmed with direct methods, such as direct sampling and scanning electron microscopy (SEM). This study advances our understanding of soil strengthening processes and permeability alterations, and is a crucial step for the use of geophysical methods as monitoring tools in microbial induced soil alterations through carbonate precipitation.

  5. Conceptual Design of Geophysical Microsatellite

    Directory of Open Access Journals (Sweden)

    Matviyenko, S.A.

    2014-10-01

    Full Text Available The article covers the issue of Earth gravitational field (EGF parameters measurement from space. The radiophysical method of measurement of gravitational frequency shift of electromagnetic radiation using existent GNSS and its two variants are developed by the author. The designlayout drawing of geophysical microsatellite, which implements the radiophysical method of EGF measurement and provides Earth plasmasphere and magnetosphere monitoring, is offered.

  6. BROADBAND DIGITAL GEOPHYSICAL TELEMETRY SYSTEM.

    Science.gov (United States)

    Seeley, Robert L.; Daniels, Jeffrey J.

    1984-01-01

    A system has been developed to simultaneously sample and transmit digital data from five remote geophysical data receiver stations to a control station that processes, displays, and stores the data. A microprocessor in each remote station receives commands from the control station over a single telemetry channel.

  7. GPU acceleration of 3D forward and backward projection using separable footprints for X-ray CT image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Meng; Fessler, Jeffrey A. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Electrical Engineering and Computer Science

    2011-07-01

    Iterative 3D image reconstruction methods can improve image quality over conventional filtered back projection (FBP) in X-ray computed tomography. However, high computational costs deter the routine use of iterative reconstruction clinically. The separable footprint method for forward and back-projection simplifies the integrals over a detector cell in a way that is quite accurate and also has a relatively efficient CPU implementation. In this project, we implemented the separable footprints method for both forward and backward projection on a graphics processing unit (GPU) with NVDIA's parallel computing architecture (CUDA). This paper describes our GPU kernels for the separable footprint method and simulation results. (orig.)

  8. Methods of X-ray CT image reconstruction from few projections

    International Nuclear Information System (INIS)

    Wang, H.

    2011-01-01

    To improve the safety (low dose) and the productivity (fast acquisition) of a X-ray CT system, we want to reconstruct a high quality image from a small number of projections. The classical reconstruction algorithms generally fail since the reconstruction procedure is unstable and suffers from artifacts. A new approach based on the recently developed 'Compressed Sensing' (CS) theory assumes that the unknown image is in some sense 'sparse' or 'compressible', and the reconstruction is formulated through a non linear optimization problem (TV/l1 minimization) by enhancing the sparsity. Using the pixel (or voxel in 3D) as basis, to apply the CS framework in CT one usually needs a 'sparsifying' transform, and combines it with the 'X-ray projector' which applies on the pixel image. In this thesis, we have adapted a 'CT-friendly' radial basis of Gaussian family called 'blob' to the CS-CT framework. The blob has better space-frequency localization properties than the pixel, and many operations, such as the X-ray transform, can be evaluated analytically and are highly parallelizable (on GPU platform). Compared to the classical Kaisser-Bessel blob, the new basis has a multi-scale structure: an image is the sum of dilated and translated radial Mexican hat functions. The typical medical objects are compressible under this basis, so the sparse representation system used in the ordinary CS algorithms is no more needed. 2D simulations show that the existing TV and l1 algorithms are more efficient and the reconstructions have better visual quality than the equivalent approach based on the pixel or wavelet basis. The new approach has also been validated on 2D experimental data, where we have observed that in general the number of projections can be reduced to about 50%, without compromising the image quality. (author) [fr

  9. Simulations of Aperture Synthesis Imaging Radar for the EISCAT_3D Project

    Science.gov (United States)

    La Hoz, C.; Belyey, V.

    2012-12-01

    EISCAT_3D is a project to build the next generation of incoherent scatter radars endowed with multiple 3-dimensional capabilities that will replace the current EISCAT radars in Northern Scandinavia. Aperture Synthesis Imaging Radar (ASIR) is one of the technologies adopted by the EISCAT_3D project to endow it with imaging capabilities in 3-dimensions that includes sub-beam resolution. Complemented by pulse compression, it will provide 3-dimensional images of certain types of incoherent scatter radar targets resolved to about 100 metres at 100 km range, depending on the signal-to-noise ratio. This ability will open new research opportunities to map small structures associated with non-homogeneous, unstable processes such as aurora, summer and winter polar radar echoes (PMSE and PMWE), Natural Enhanced Ion Acoustic Lines (NEIALs), structures excited by HF ionospheric heating, meteors, space debris, and others. To demonstrate the feasibility of the antenna configurations and the imaging inversion algorithms a simulation of synthetic incoherent scattering data has been performed. The simulation algorithm incorporates the ability to control the background plasma parameters with non-homogeneous, non-stationary components over an extended 3-dimensional space. Control over the positions of a number of separated receiving antennas, their signal-to-noise-ratios and arriving phases allows realistic simulation of a multi-baseline interferometric imaging radar system. The resulting simulated data is fed into various inversion algorithms. This simulation package is a powerful tool to evaluate various antenna configurations and inversion algorithms. Results applied to realistic design alternatives of EISCAT_3D will be described.

  10. Marysville, Montana, Geothermal Project: Geological and Geophysical Exploration at Marysville Geothermal Area: 1973 Results (With a Section on ''Contemporary Seismicity in the Helena, Montana Region'')

    Energy Technology Data Exchange (ETDEWEB)

    Blackwell, D.D.; Brott, C.A.; Goforth, T.T.; Holdaway, M.J.; Morgan, P.; Friedline, R.; Smith, R.L.

    1974-04-01

    This report describes field geological and geophysical investigations of the Marysville geothermal area, including geological mapping, sample collection, a ground total field magnetic survey, gravity survey, seismic ground noise survey, microearthquake survey, and heat flow study. Although sufficient data are not available, it is likely that a magma chamber is the heat source. A second section, ''Contemporary Seismicity in the Helena, Montana, Region'' examines the coincidence of high heat flow and earthquake swarm activity in this region. (GRA)

  11. Development and comparison of projection and image space 3D nodule insertion techniques

    Science.gov (United States)

    Robins, Marthony; Solomon, Justin; Sahbaee, Pooyan; Samei, Ehsan

    2016-04-01

    This study aimed to develop and compare two methods of inserting computerized virtual lesions into CT datasets. 24 physical (synthetic) nodules of three sizes and four morphologies were inserted into an anthropomorphic chest phantom (LUNGMAN, KYOTO KAGAKU). The phantom was scanned (Somatom Definition Flash, Siemens Healthcare) with and without nodules present, and images were reconstructed with filtered back projection and iterative reconstruction (SAFIRE) at 0.6 mm slice thickness using a standard thoracic CT protocol at multiple dose settings. Virtual 3D CAD models based on the physical nodules were virtually inserted (accounting for the system MTF) into the nodule-free CT data using two techniques. These techniques include projection-based and image-based insertion. Nodule volumes were estimated using a commercial segmentation tool (iNtuition, TeraRecon, Inc.). Differences were tested using paired t-tests and R2 goodness of fit between the virtually and physically inserted nodules. Both insertion techniques resulted in nodule volumes very similar to the real nodules (values were all <0.97 for both insertion techniques. These data imply that these techniques can confidently be used as a means of inserting virtual nodules in CT datasets. These techniques can be instrumental in building hybrid CT datasets composed of patient images with virtually inserted nodules.

  12. Engaging stakeholder communities as body image intervention partners: The Body Project as a case example.

    Science.gov (United States)

    Becker, Carolyn Black; Perez, Marisol; Kilpela, Lisa Smith; Diedrichs, Phillippa C; Trujillo, Eva; Stice, Eric

    2017-04-01

    Despite recent advances in developing evidence-based psychological interventions, substantial changes are needed in the current system of intervention delivery to impact mental health on a global scale (Kazdin & Blase, 2011). Prevention offers one avenue for reaching large populations because prevention interventions often are amenable to scaling-up strategies, such as task-shifting to lay providers, which further facilitate community stakeholder partnerships. This paper discusses the dissemination and implementation of the Body Project, an evidence-based body image prevention program, across 6 diverse stakeholder partnerships that span academic, non-profit and business sectors at national and international levels. The paper details key elements of the Body Project that facilitated partnership development, dissemination and implementation, including use of community-based participatory research methods and a blended train-the-trainer and task-shifting approach. We observed consistent themes across partnerships, including: sharing decision making with community partners, engaging of community leaders as gatekeepers, emphasizing strengths of community partners, working within the community's structure, optimizing non-traditional and/or private financial resources, placing value on cost-effectiveness and sustainability, marketing the program, and supporting flexibility and creativity in developing strategies for evolution within the community and in research. Ideally, lessons learned with the Body Project can be generalized to implementation of other body image and eating disorder prevention programs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. ABrIL - Advanced Brain Imaging Lab : a cloud based computation environment for cooperative neuroimaging projects.

    Science.gov (United States)

    Neves Tafula, Sérgio M; Moreira da Silva, Nádia; Rozanski, Verena E; Silva Cunha, João Paulo

    2014-01-01

    Neuroscience is an increasingly multidisciplinary and highly cooperative field where neuroimaging plays an important role. Neuroimaging rapid evolution is demanding for a growing number of computing resources and skills that need to be put in place at every lab. Typically each group tries to setup their own servers and workstations to support their neuroimaging needs, having to learn from Operating System management to specific neuroscience software tools details before any results can be obtained from each setup. This setup and learning process is replicated in every lab, even if a strong collaboration among several groups is going on. In this paper we present a new cloud service model - Brain Imaging Application as a Service (BiAaaS) - and one of its implementation - Advanced Brain Imaging Lab (ABrIL) - in the form of an ubiquitous virtual desktop remote infrastructure that offers a set of neuroimaging computational services in an interactive neuroscientist-friendly graphical user interface (GUI). This remote desktop has been used for several multi-institution cooperative projects with different neuroscience objectives that already achieved important results, such as the contribution to a high impact paper published in the January issue of the Neuroimage journal. The ABrIL system has shown its applicability in several neuroscience projects with a relatively low-cost, promoting truly collaborative actions and speeding up project results and their clinical applicability.

  14. Public financing of research projects in Poland – its image and consequences?

    Directory of Open Access Journals (Sweden)

    Feldy Marzena

    2016-12-01

    Full Text Available Both the size of appropriation as well as their distribution have had a profound impact on the shape and activities of the science sector. The creation of a fair system of distribution of public resources to research that will also facilitate the effective implementation of the pursued scientific policy goals represents a major challenge. The issue of the determination of the right proportions of individual distribution channels remains critical. Despite this task being the responsibility of the State, establishing cooperation in this respect with the scientific community is desirable. The implementation of solutions that raise the concerns of scientists leads to system instability and reduced effectiveness which is manifest among others in a lower level of indicators of scientific excellence and innovation in the country. These observations are pertinent to Poland where the manner in which scientific institutes operate were changed under the 2009–2011 reform. A neoliberal operating model based on competitiveness and rewarding of top rated scientific establishments and scientists was implemented. In light of these facts, the initiation of research that will provide information on how the implemented changes are perceived by the scientific community seems to be appropriate. The aim of this article is in particlar presenting how the project model of financing laid down under the reform is perceived and what kind of image has been shaped among Polish scientists. In order to gain a comprehensive picture of the situation, both the rational and emotional image was subject to analysis. The conclusions regarding the perception of the project model were drawn on the basis of empirical materials collected in a qualitative study the specifics of which will be presented in the chapter on methodology. Prior to that, the author discusses the basic models for the distribution of state support for science and characterises the most salient features of the

  15. Implementation of a high-resolution workstation for primary diagnosis of projection radiography images

    Science.gov (United States)

    Good, Walter F.; Herron, John M.; Maitz, Glenn S.; Gur, David; Miller, Stephen L.; Straub, William H.; Fuhrman, Carl R.

    1990-08-01

    We designed and implemented a high-resolution video workstation as the central hardware component in a comprehensive multi-project program comparing the use of digital and film modalities. The workstation utilizes a 1.8 GByte real-time disk (RCI) capable of storing 400 full-resolution images and two Tektronix (GMA251) display controllers with 19" monitors (GMA2O2). The display is configured in a portrait format with a resolution of 1536 x 2048 x 8 bit, and operates at 75 Hz in a noninterlaced mode. Transmission of data through a 12 to 8 bit lookup table into the display controllers occurs at 20 MBytes/second (.35 seconds per image). The workstation allows easy use of brightness (level) and contrast (window) to be manipulated with a trackball, and various processing options can be selected using push buttons. Display of any of the 400 images is also performed at 20MBytes/sec (.35 sec/image). A separate text display provides for the automatic display of patient history data and for a scoring form through which readers can interact with the system by means of a computer mouse. In addition, the workstation provides for the randomization of cases and for the immediate entry of diagnostic responses into a master database. Over the past year this workstation has been used for over 10,000 readings in diagnostic studies related to 1) image resolution; 2) film vs. soft display; 3) incorporation of patient history data into the reading process; and 4) usefulness of image processing.

  16. A new EU-funded project for enhanced real-time imaging for radiotherapy

    CERN Multimedia

    KTT Life Sciences Unit

    2011-01-01

    ENTERVISION (European training network for digital imaging for radiotherapy) is a new Marie Curie Initial Training Network coordinated by CERN, which brings together multidisciplinary researchers to carry out R&D in physics techniques for application in the clinical environment.   ENTERVISION was established in response to a critical need to reinforce research in online 3D digital imaging and to train professionals in order to deliver some of the key elements for early detection and more precise treatment of tumours. The main goal of the project is to train researchers who will help contribute to technical developments in an exciting multidisciplinary field, where expertise from physics, medicine, electronics, informatics, radiobiology and engineering merges and catalyses the advancement of cancer treatment. With this aim in mind, ENTERVISION brings together ten academic institutes and research centres, as well as the two leading European companies in particle therapy, IBA and Siemens. &ldq...

  17. Low-complexity camera digital signal imaging for video document projection system

    Science.gov (United States)

    Hsia, Shih-Chang; Tsai, Po-Shien

    2011-04-01

    We present high-performance and low-complexity algorithms for real-time camera imaging applications. The main functions of the proposed camera digital signal processing (DSP) involve color interpolation, white balance, adaptive binary processing, auto gain control, and edge and color enhancement for video projection systems. A series of simulations demonstrate that the proposed method can achieve good image quality while keeping computation cost and memory requirements low. On the basis of the proposed algorithms, the cost-effective hardware core is developed using Verilog HDL. The prototype chip has been verified with one low-cost programmable device. The real-time camera system can achieve 1270 × 792 resolution with the combination of extra components and can demonstrate each DSP function.

  18. Grid Databases for Shared Image Analysis in the MammoGrid Project

    CERN Document Server

    Amendolia, S R; Hauer, T; Manset, D; McClatchey, R; Odeh, M; Reading, T; Rogulin, D; Schottlander, D; Solomonides, T

    2004-01-01

    The MammoGrid project aims to prove that Grid infrastructures can be used for collaborative clinical analysis of database-resident but geographically distributed medical images. This requires: a) the provision of a clinician-facing front-end workstation and b) the ability to service real-world clinician queries across a distributed and federated database. The MammoGrid project will prove the viability of the Grid by harnessing its power to enable radiologists from geographically dispersed hospitals to share standardized mammograms, to compare diagnoses (with and without computer aided detection of tumours) and to perform sophisticated epidemiological studies across national boundaries. This paper outlines the approach taken in MammoGrid to seamlessly connect radiologist workstations across a Grid using an "information infrastructure" and a DICOM-compliant object model residing in multiple distributed data stores in Italy and the UK

  19. THE EUROSDR PROJECT "RADIOMETRIC ASPECTS OF DIGITAL PHOTOGRAMMETRIC IMAGES" – RESULTS OF THE EMPIRICAL PHASE

    Directory of Open Access Journals (Sweden)

    E. Honkavaara

    2012-09-01

    Full Text Available This article presents the empirical research carried out in the context of the multi-site EuroSDR project "Radiometric aspects of digital photogrammetric images" and provides highlights of the results. The investigations have considered the vicarious radiometric and spatial resolution validation and calibration of the sensor system, radiometric processing of the image blocks either by performing relative radiometric block equalization or into absolutely reflectance calibrated products, and finally aspects of practical applications on NDVI layer generation and tree species classification. The data sets were provided by Leica Geosystems ADS40 and Intergraph DMC and the participants represented stakeholders in National Mapping Authorities, software development and research. The investigations proved the stability and quality of evaluated imaging systems with respect to radiometry and optical system. The first new-generation methods for reflectance calibration and equalization of photogrammetric image block data provided promising accuracy and were also functional from the productivity and usability points of view. The reflectance calibration methods provided up to 5% accuracy without any ground reference. Application oriented results indicated that automatic interpretation methods will benefit from the optimal use of radiometrically accurate multi-view photogrammetric imagery.

  20. Strain Imaging of Nanoscale Semiconductor Heterostructures with X-Ray Bragg Projection Ptychography

    Science.gov (United States)

    Holt, Martin V.; Hruszkewycz, Stephan O.; Murray, Conal E.; Holt, Judson R.; Paskiewicz, Deborah M.; Fuoss, Paul H.

    2014-04-01

    We report the imaging of nanoscale distributions of lattice strain and rotation in complementary components of lithographically engineered epitaxial thin film semiconductor heterostructures using synchrotron x-ray Bragg projection ptychography (BPP). We introduce a new analysis method that enables lattice rotation and out-of-plane strain to be determined independently from a single BPP phase reconstruction, and we apply it to two laterally adjacent, multiaxially stressed materials in a prototype channel device. These results quantitatively agree with mechanical modeling and demonstrate the ability of BPP to map out-of-plane lattice dilatation, a parameter critical to the performance of electronic materials.

  1. Improved superficial brain hemorrhage visualization in susceptibility weighted images by constrained minimum intensity projection

    Science.gov (United States)

    Castro, Marcelo A.; Pham, Dzung L.; Butman, John

    2016-03-01

    Minimum intensity projection is a technique commonly used to display magnetic resonance susceptibility weighted images, allowing the observer to better visualize hemorrhages and vasculature. The technique displays the minimum intensity in a given projection within a thick slab, allowing different connectivity patterns to be easily revealed. Unfortunately, the low signal intensity of the skull within the thick slab can mask superficial tissues near the skull base and other regions. Because superficial microhemorrhages are a common feature of traumatic brain injury, this effect limits the ability to proper diagnose and follow up patients. In order to overcome this limitation, we developed a method to allow minimum intensity projection to properly display superficial tissues adjacent to the skull. Our approach is based on two brain masks, the largest of which includes extracerebral voxels. The analysis of the rind within both masks containing the actual brain boundary allows reclassification of those voxels initially missed in the smaller mask. Morphological operations are applied to guarantee accuracy and topological correctness, and the mean intensity within the mask is assigned to all outer voxels. This prevents bone from dominating superficial regions in the projection, enabling superior visualization of cortical hemorrhages and vessels.

  2. Some key techniques of SPOT-5 image processing in new national land and resources investigation project

    Science.gov (United States)

    Xue, Changsheng; Li, Qingquan; Li, Deren

    2004-02-01

    In 1988, the detail information on land resource was investigated in China. Fourteen years later, it has changed a lot. It is necessary that the second land resource detailed investigation should be implemented. On this condition, the New National Land and Resources Investigation Project in China, which will last 12 years, has been started since 1999. The project is directly under the administration of the Ministry of Land and Resource (MLR). It was organized and implemented By China Geological, China Land Surveying and Planning Institute (CLSPI) and Information Center of MLR. It is a grand and cross century project supported by the Central Finance, based on State and public interests and strategic characteristics. Up to now, "Land Use Dynamic Monitoring By Remote Sensing," "Arable Land Resource Investigation," "Rural Collective Land Property Right Investgiation," "Establishment of Public Consulting Standardization of Cadastral Information," "Land Resource Fundamental Maps and Data Updating," "Urban Land Price Investigation and Intensive Utilization Potential Capacity Evaluation," "Farmland Classification, Gradation, and Evaluation," "Land Use Database Construction at City or County Level" 8 subprojects have had the preliminary achievements. In this project, SPOT-1/2/4 and Landsat-7 TM data were always applied to monitor land use dynamic change as the main data resource. Certainly, IRS, CBERS-2, and IKONOS data also were tested in small areas. In 2002, the SPOT-5 data, whose spatial resolution of the panchromatic image is 2.5 meters and the spectral one is 10 meters, were applied into update the land use base map at the 1:10000 scale in 26 Chinese cities. The purpose in this paper is to communicate the experience of SPOT-5 image processing with the colleagues.

  3. Image restoration by the method of convex projections: part 1 theory.

    Science.gov (United States)

    Youla, D C; Webb, H

    1982-01-01

    A projection operator onto a closed convex set in Hilbert space is one of the few examples of a nonlinear map that can be defined in simple abstract terms. Moreover, it minimizes distance and is nonexpansive, and therefore shares two of the more important properties of ordinary linear orthogonal projections onto closed linear manifolds. In this paper, we exploit the properties of these operators to develop several iterative algorithms for image restoration from partial data which permit any number of nonlinear constraints of a certain type to be subsumed automatically. Their common conceptual basis is as follows. Every known property of an original image f is envisaged as restricting it to lie in a well-defined closed convex set. Thus, m such properties place f in the intersection E(0) = E(i) of the corresponding closed convex sets E(1),E(2),...EE(m). Given only the projection operators PE(i) onto the individual E(i)'s, i = 1 --> m, we restore f by recursive means. Clearly, in this approach, the realization of the P(i)'s in a Hilbert space setting is one of the major synthesis problems. Section I describes the geometrical significance of the three main theorems in considerable detail, and most of the underlying ideas are illustrated with the aid of simple diagrams. Section II presents rules for the numerical implementation of 11 specific projection operators which are found to occur frequently in many signal-processing applications, and the Appendix contains proofs of all the major results.

  4. Marine Geology and Geophysics Field Course Offered by The University of Texas Institute for Geophysics

    Science.gov (United States)

    Duncan, D.; Davis, M. B.; Allison, M. A.; Gulick, S. P.; Goff, J. A.; Saustrup, S.

    2012-12-01

    particle size analysis and initial post-processing of geophysical data. During the course's final week, teams return to the classroom where they integrate, interpret, and visualize data in a final project using industry-standard software such as Focus, Landmark, Caris, and Fledermaus. The course concludes with a series of professional-level final presentations and discussions with academic and industry supporters in which students examine the geologic history and sedimentary processes of the studied area of the Gulf Coast continental shelf. After completion, students report a greater understanding of marine geology and geophysics through the course's intensive, hands-on, team approach and low instructor to student ratio (12 students, three faculty, and three teaching assistants). This course satisfies field experience requirements for some degree programs and thus provides a unique alternative to land-based field courses.

  5. Mammography with and without radiolucent positioning sheets: Comparison of projected breast area, pain experience, radiation dose and technical image quality

    NARCIS (Netherlands)

    Timmers, Janine; ten Voorde, Marloes; van Engen, Ruben E.; van Landsveld-Verhoeven, Cary; Pijnappel, Ruud; Droogh-de Greve, Kitty; den Heeten, Gerard J.; Broeders, Mireille J. M.

    2015-01-01

    To compare projected breast area, image quality, pain experience and radiation dose between mammography performed with and without radiolucent positioning sheets. 184 women screened in the Dutch breast screening programme (May-June 2012) provided written informed consent to have one additional image

  6. Geophysical interpretation using integral equations

    CERN Document Server

    Eskola, L

    1992-01-01

    Along with the general development of numerical methods in pure and applied to apply integral equations to geophysical modelling has sciences, the ability improved considerably within the last thirty years or so. This is due to the successful derivation of integral equations that are applicable to the modelling of complex structures, and efficient numerical algorithms for their solution. A significant stimulus for this development has been the advent of fast digital computers. The purpose of this book is to give an idea of the principles by which boundary-value problems describing geophysical models can be converted into integral equations. The end results are the integral formulas and integral equations that form the theoretical framework for practical applications. The details of mathematical analysis have been kept to a minimum. Numerical algorithms are discussed only in connection with some illustrative examples involving well-documented numerical modelling results. The reader is assu­ med to have a back...

  7. Geophysical and solar activity indices

    Science.gov (United States)

    Bossy, L.; Lemaire, J.

    1984-04-01

    A large number of geophysicists try to correlate their observations with one or even a series of different geophysical or solar activity indices. Yet the right choice of the most appropriate index with which to correlate depends mainly on our understanding of the physical cause-effect relationship between the new set of observations and the index chosen. This best choice will therefore depend on our good understanding of the methods of measurement and derivation of the adopted index in such correlative studies. It relies also on our awareness of the range of applicability of the indices presently available as well as on our understanding of their limitations. It was to achieve these goals that a series of general lectures on geophysical and solar activity indices was organized by L. Bossy and J. Lemaire (Institut d'Aeronomie Spatiale de Belgique (IASB), Brussels), March 26-29, 1984 at Han-sur-Lesse, Belgium.

  8. Mathematics applied to nuclear geophysics

    International Nuclear Information System (INIS)

    Pereira, E.B.; Nordemann, D.J.R.

    1987-01-01

    One of the powerful auxiliary to nuclear geophysics is the obtention and interpretation of the alpha and gamma radiation spectra. This work discuss, qualitative and quantitative, the lost information problem, motivated by the noise in the process of information codification. The decodification process must be suppield by the appropriate mathematical model on the measure system to recovery the information from nuclear source. (C.D.G.) [pt

  9. Geophysical methods in uranium mining

    International Nuclear Information System (INIS)

    Koehler, K.

    1989-01-01

    In uranium prospecting, exploration, milling, and mining there is an urgent need to have information on the concentration of uranium at all steps of handling uranium containing materials. To gain this information in an effective way modern geophysical methods have to be applied. Publications of the IAEA and NEA in this field are reviewed in order to characterize the state of the art of these methods. 55 refs

  10. Comparison analysis between filtered back projection and algebraic reconstruction technique on microwave imaging

    Science.gov (United States)

    Ramadhan, Rifqi; Prabowo, Rian Gilang; Aprilliyani, Ria; Basari

    2018-02-01

    Victims of acute cancer and tumor are growing each year and cancer becomes one of the causes of human deaths in the world. Cancers or tumor tissue cells are cells that grow abnormally and turn to take over and damage the surrounding tissues. At the beginning, cancers or tumors do not have definite symptoms in its early stages, and can even attack the tissues inside of the body. This phenomena is not identifiable under visual human observation. Therefore, an early detection system which is cheap, quick, simple, and portable is essensially required to anticipate the further development of cancer or tumor. Among all of the modalities, microwave imaging is considered to be a cheaper, simple, and portable system method. There are at least two simple image reconstruction algorithms i.e. Filtered Back Projection (FBP) and Algebraic Reconstruction Technique (ART), which have been adopted in some common modalities. In this paper, both algorithms will be compared by reconstructing the image from an artificial tissue model (i.e. phantom), which has two different dielectric distributions. We addressed two performance comparisons, namely quantitative and qualitative analysis. Qualitative analysis includes the smoothness of the image and also the success in distinguishing dielectric differences by observing the image with human eyesight. In addition, quantitative analysis includes Histogram, Structural Similarity Index (SSIM), Mean Squared Error (MSE), and Peak Signal-to-Noise Ratio (PSNR) calculation were also performed. As a result, quantitative parameters of FBP might show better values than the ART. However, ART is likely more capable to distinguish two different dielectric value than FBP, due to higher contrast in ART and wide distribution grayscale level.

  11. Prevalence of incidental findings on magnetic resonance imaging: Cuban project to map the human brain

    International Nuclear Information System (INIS)

    Hernandez Gonzalez, Gertrudis de los Angeles; Alvarez Sanchez, Marilet; Jordan Gonzalez, Jose

    2010-01-01

    To determine the prevalence of incidental findings in healthy subjects of the Cuban Human Brain Mapping Project sample, it was performed a retrospective descriptive study of the magnetic resonance imaging (MRI) obtained from 394 healthy subjects that make up the sample of the project, between 2006-2007, with an age range of 18 to 68 years (mean 33,12), of which 269 (68,27 %) are male and 125 (31,73 %) are women. It was shown that 40,36 % had one or more anomaly in the magnetic resonance imaging (MRI). In total, the number of incidental findings was 188, 23,6 % of which were brain findings and 24,11 % were non-brain findings, among the latter, were the sinusopathy with 20,81 % and maxillary polyps with 3,30 %. The most prevalent brain findings were: intrasellar arachnoidocele, 11,93 %, followed by the prominence of the pituitary gland, 5,84 %, ventricular asymmetry, 1,77 % and bone defects, 1,02 %. Other brain abnormalities found with very low prevalence had no pathological significance, except for two cases with brain tumor, which were immediately sent to a specialist. Incidental findings in MRI are common in the general population (40,36 %), being the sinusopathy, and intrasellar arachnoidocele the most common findings. Asymptomatic individuals who have any type of structural abnormality provide invaluable information on the prevalence of these abnormalities in a presumably healthy population, which may be used as references for epidemiological studies

  12. SAGE (Summer of Applied Geophysical Experience): Learning Geophysics by Doing Geophysics

    Science.gov (United States)

    Jiracek, G. R.; Baldridge, W. S.; Biehler, S.; Braile, L. W.; Ferguson, J. F.; Gilpin, B. E.; Pellerin, L.

    2005-12-01

    SAGE, a field-based educational program in applied geophysical methods has been an REU site for 16 years and completed its 23rd year of operation in July 2005. SAGE teaches the major geophysical exploration methods (including seismics, gravity, magnetics, and electromagnetics) and applies them to the solution of specific local and regional geologic problems. These include delineating buried hazardous material; mapping archaeological sites; and studying the structure, tectonics, and water resources of the Rio Grande rift in New Mexico. Nearly 600 graduates, undergraduates, and professionals have attended SAGE since 1983. Since 1990 REU students have numbered 219 coming from dozens of different campuses. There have been 124 underrepresented REU students including 100 women, 14 Hispanics, 7 Native Americans, and 3 African Americans. Tracking of former REU students has revealed that 81% have gone on to graduate school. Keys to the success of SAGE are hands-on immersion in geophysics for one month and a partnership between academia, industry, and a federal laboratory. Successful approaches at SAGE include: 1) application of the latest equipment by all students; 2) continued updating of equipment, computers, and software by organizing universities and industry affiliates; 3) close ties with industry who provide supplemental instruction, furnish new equipment and software, and alert students to the current industry trends and job opportunities; 4) two-team, student data analysis structure that simultaneously addresses specific geophysical techniques and their integration; and 5) oral and written reports patterned after professional meetings and journals. An eight member, 'blue ribbon' advisory panel from academia, industry, and the federal government has been set up to maintain the vitality of SAGE by addressing such issues as funding, new faculty, organization, and vision. SAGE is open to students from any university (or organization) with backgrounds including

  13. Environmental and regulatory considerations when planning a geophysical program

    International Nuclear Information System (INIS)

    Down-Cicoria, C.

    1999-01-01

    Public concerns regarding the environmental impact of geophysical programs have resulted in more pressure on the federal and provincial governments to regulate and protect unique ecosites. In the past decade, about 1 million kilometres of seismic have been shot by the petroleum industry in Alberta alone, representing about 70,000 hectares of land base. This paper reviewed how a preliminary assessment of any geophysical project should consider the effects of all projects on the terrain, climate, vegetation, soils, fisheries, wildlife, aquatic ecosystems, heritage resources, and timber dispositions. Geo-administrative boundaries, field assessments, environmental assessments and mitigation measures such as low impact line cutting methods, timing methods, and heli-portable operations must also be considered. Special considerations when planning a three-dimensional program were highlighted. Certain equipment suitable as mitigation measures such as mulchers, hydro-axes, enviro-drills, biodegradable lathes, tracked/low PSI equipment, and doglegs were also reviewed. 15 refs., 2 tabs., 18 figs

  14. Automatic tracking of implanted fiducial markers in cone beam CT projection images

    International Nuclear Information System (INIS)

    Marchant, T. E.; Skalski, A.; Matuszewski, B. J.

    2012-01-01

    Purpose: This paper describes a novel method for simultaneous intrafraction tracking of multiple fiducial markers. Although the proposed method is generic and can be adopted for a number of applications including fluoroscopy based patient position monitoring and gated radiotherapy, the tracking results presented in this paper are specific to tracking fiducial markers in a sequence of cone beam CT projection images. Methods: The proposed method is accurate and robust thanks to utilizing the mean shift and random sampling principles, respectively. The performance of the proposed method was evaluated with qualitative and quantitative methods, using data from two pancreatic and one prostate cancer patients and a moving phantom. The ground truth, for quantitative evaluation, was calculated based on manual tracking preformed by three observers. Results: The average dispersion of marker position error calculated from the tracking results for pancreas data (six markers tracked over 640 frames, 3840 marker identifications) was 0.25 mm (at iscoenter), compared with an average dispersion for the manual ground truth estimated at 0.22 mm. For prostate data (three markers tracked over 366 frames, 1098 marker identifications), the average error was 0.34 mm. The estimated tracking error in the pancreas data was < 1 mm (2 pixels) in 97.6% of cases where nearby image clutter was detected and in 100.0% of cases with no nearby image clutter. Conclusions: The proposed method has accuracy comparable to that of manual tracking and, in combination with the proposed batch postprocessing, superior robustness. Marker tracking in cone beam CT (CBCT) projections is useful for a variety of purposes, such as providing data for assessment of intrafraction motion, target tracking during rotational treatment delivery, motion correction of CBCT, and phase sorting for 4D CBCT.

  15. Macro optical projection tomography for large scale 3D imaging of plant structures and gene activity.

    Science.gov (United States)

    Lee, Karen J I; Calder, Grant M; Hindle, Christopher R; Newman, Jacob L; Robinson, Simon N; Avondo, Jerome J H Y; Coen, Enrico S

    2017-01-01

    Optical projection tomography (OPT) is a well-established method for visualising gene activity in plants and animals. However, a limitation of conventional OPT is that the specimen upper size limit precludes its application to larger structures. To address this problem we constructed a macro version called Macro OPT (M-OPT). We apply M-OPT to 3D live imaging of gene activity in growing whole plants and to visualise structural morphology in large optically cleared plant and insect specimens up to 60 mm tall and 45 mm deep. We also show how M-OPT can be used to image gene expression domains in 3D within fixed tissue and to visualise gene activity in 3D in clones of growing young whole Arabidopsis plants. A further application of M-OPT is to visualise plant-insect interactions. Thus M-OPT provides an effective 3D imaging platform that allows the study of gene activity, internal plant structures and plant-insect interactions at a macroscopic scale. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  16. Accelerated perturbation-resilient block-iterative projection methods with application to image reconstruction.

    Science.gov (United States)

    Nikazad, T; Davidi, R; Herman, G T

    2012-03-01

    We study the convergence of a class of accelerated perturbation-resilient block-iterative projection methods for solving systems of linear equations. We prove convergence to a fixed point of an operator even in the presence of summable perturbations of the iterates, irrespective of the consistency of the linear system. For a consistent system, the limit point is a solution of the system. In the inconsistent case, the symmetric version of our method converges to a weighted least squares solution. Perturbation resilience is utilized to approximate the minimum of a convex functional subject to the equations. A main contribution, as compared to previously published approaches to achieving similar aims, is a more than an order of magnitude speed-up, as demonstrated by applying the methods to problems of image reconstruction from projections. In addition, the accelerated algorithms are illustrated to be better, in a strict sense provided by the method of statistical hypothesis testing, than their unaccelerated versions for the task of detecting small tumors in the brain from X-ray CT projection data.

  17. Geophysical excitation of nutation - comparison of different models

    Czech Academy of Sciences Publication Activity Database

    Vondrák, Jan; Ron, Cyril

    2014-01-01

    Roč. 11, č. 3 (2014), s. 193-200 ISSN 1214-9705 R&D Projects: GA ČR GA13-15943S Institutional research plan: CEZ:AV0Z1003909 Institutional support: RVO:67985815 Keywords : rotation of the Earth * geophysical excitations * geomagnetic jerks * celestial pole offsets * free core nutation Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.389, year: 2014

  18. Coherence between geophysical excitations and celestial pole offsets

    Czech Academy of Sciences Publication Activity Database

    Ron, Cyril; Vondrák, Jan

    2011-01-01

    Roč. 8, č. 3 (2011), s. 243-247 ISSN 1214-9705. [Czech-Polish Workshop on Recent Geodynamics of the Sudeten and Adjacent Areas. Třešť, 04.11.2010-06.11. 2010] R&D Projects: GA ČR GA205/08/0908 Institutional research plan: CEZ:AV0Z10030501 Keywords : geophysical excitations * celestial pole offsets * coherence Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.530, year: 2011

  19. Geophysical fluids, geomagnetic jerks, and their impact on Earth orientation

    Czech Academy of Sciences Publication Activity Database

    Vondrák, Jan; Ron, Cyril

    2017-01-01

    Roč. 96, č. 1 (2017), s. 51-60 ISSN 0373-3742. [National Conference of Astronomers of Serbia /17./. Belgrade, 23.09.2014-27.09.2014] R&D Projects: GA ČR GA13-15943S Institutional support: RVO:67985815 Keywords : Earth orientation * geophysical fluids * geomagnetic jerks Subject RIV: DE - Earth Magnetism, Geodesy, Geography OBOR OECD: Physical geography

  20. Addressing the difficulty of changing fields in geophysics

    Science.gov (United States)

    Civilini, F.; Savage, M. K.

    2014-12-01

    Geophysics is a wonderfully diverse field of study, encompassing a variety of disciplines greatly different from one other. Even within the same discipline, various branches of study can have drastically different vocabulary and methodologies. The difficulty of breaking this "jargon" barrier is also an important reminder for scientists of how critical it is to clearly and concisely convey information. This presentation will focus on strategies that students can focus on to ease a transition between fields in geophysics. I believe that a student changing disciplines should proceed in the following steps: [1] Do a cursory literature review to find a review paper of the desired topic and work backwards through the details until a level of understanding or recognition is reached, [2] Obtain a clear physical understanding of the data and methods of the proposed study, and [3] Establish a support network through the research group or elsewhere which will recognize the areas in which the student is behind and offer remedies in a supportive and productive manner. These strategies are based on my own personal experience changing from music to geophysics in my undergrad and working on projects spanning various subdisciplines of geophysics during my Masters and PhD. It is worthwhile for research groups to spend the time to mentor students switching from other disciplines because those students will in time be able to observe the research in a different way than their peers, and easily adapt to changes of direction within the research.

  1. Objective and expert-independent validation of retinal image registration algorithms by a projective imaging distortion model

    NARCIS (Netherlands)

    Lee, Sangyeol; Reinhardt, Joseph M.; Cattin, Philippe C.; Abramoff, M.D.

    2010-01-01

    Fundus camera imaging of the retina is widely used to diagnose and manage ophthalmologic disorders including diabetic retinopathy, glaucoma, and age-related macular degeneration. Retinal images typically have a limited field of view, and multiple images can be joined together using an image

  2. Femtosecond few- to single-electron point-projection microscopy for nanoscale dynamic imaging

    Directory of Open Access Journals (Sweden)

    A. R. Bainbridge

    2016-03-01

    Full Text Available Femtosecond electron microscopy produces real-space images of matter in a series of ultrafast snapshots. Pulses of electrons self-disperse under space-charge broadening, so without compression, the ideal operation mode is a single electron per pulse. Here, we demonstrate femtosecond single-electron point projection microscopy (fs-ePPM in a laser-pump fs-e-probe configuration. The electrons have an energy of only 150 eV and take tens of picoseconds to propagate to the object under study. Nonetheless, we achieve a temporal resolution with a standard deviation of 114 fs (equivalent to a full-width at half-maximum of 269 ± 40 fs combined with a spatial resolution of 100 nm, applied to a localized region of charge at the apex of a nanoscale metal tip induced by 30 fs 800 nm laser pulses at 50 kHz. These observations demonstrate real-space imaging of reversible processes, such as tracking charge distributions, is feasible whilst maintaining femtosecond resolution. Our findings could find application as a characterization method, which, depending on geometry, could resolve tens of femtoseconds and tens of nanometres. Dynamically imaging electric and magnetic fields and charge distributions on sub-micron length scales opens new avenues of ultrafast dynamics. Furthermore, through the use of active compression, such pulses are an ideal seed for few-femtosecond to attosecond imaging applications which will access sub-optical cycle processes in nanoplasmonics.

  3. X-ray CT core imaging of Oman Drilling Project on D/V CHIKYU

    Science.gov (United States)

    Michibayashi, K.; Okazaki, K.; Leong, J. A. M.; Kelemen, P. B.; Johnson, K. T. M.; Greenberger, R. N.; Manning, C. E.; Harris, M.; de Obeso, J. C.; Abe, N.; Hatakeyama, K.; Ildefonse, B.; Takazawa, E.; Teagle, D. A. H.; Coggon, J. A.

    2017-12-01

    We obtained X-ray computed tomography (X-ray CT) images for all cores (GT1A, GT2A, GT3A and BT1A) in Oman Drilling Project Phase 1 (OmanDP cores), since X-ray CT scanning is a routine measurement of the IODP measurement plan onboard Chikyu, which enables the non-destructive observation of the internal structure of core samples. X-ray CT images provide information about chemical compositions and densities of the cores and is useful for assessing sample locations and the quality of the whole-round samples. The X-ray CT scanner (Discovery CT 750HD, GE Medical Systems) on Chikyu scans and reconstructs the image of a 1.4 m section in 10 minutes and produces a series of scan images, each 0.625 mm thick. The X-ray tube (as an X-ray source) and the X-ray detector are installed inside of the gantry at an opposing position to each other. The core sample is scanned in the gantry with the scanning rate of 20 mm/sec. The distribution of attenuation values mapped to an individual slice comprises the raw data that are used for subsequent image processing. Successive two-dimensional (2-D) slices of 512 x 512 pixels yield a representation of attenuation values in three-dimensional (3-D) voxels of 512 x 512 by 1600 in length. Data generated for each core consist of core-axis-normal planes (XY planes) of X-ray attenuation values with dimensions of 512 × 512 pixels in 9 cm × 9 cm cross-section, meaning at the dimensions of a core section, the resolution is 0.176 mm/pixel. X-ray intensity varies as a function of X-ray path length and the linear attenuation coefficient (LAC) of the target material is a function of the chemical composition and density of the target material. The basic measure of attenuation, or radiodensity, is the CT number given in Hounsfield units (HU). CT numbers of air and water are -1000 and 0, respectively. Our preliminary results show that CT numbers of OmanDP cores are well correlated to gamma ray attenuation density (GRA density) as a function of chemical

  4. Effect of number of of projections on inverse radon transform based image reconstruction by using filtered back-projection for parallel beam transmission tomography

    International Nuclear Information System (INIS)

    Qureshi, S.A.; Mirza, S.M.; Arif, M.

    2007-01-01

    This paper present the effect of number of projections on inverse Radon transform (IRT) estimation using filtered back-projection (FBP) technique for parallel beam transmission tomography. The head phantom and the lung phantom have been used in this work. Various filters used in this study include Ram-Lak, Shepp-Logan, Cosin, Hamming and Hanning filters. The slices have been reconstructed by increasing the number of projections through parallel beam transmission tomography keeping the projections uniformly distributed. The Euclidean and Mean Squared errors and peak signal-to-noise ratio (PSNR) have been analyzed for their sensitiveness as functions of number of projections. It has found that image quality improves with the number of projections but at the cost of the computer time. The error has been minimized to get the best approximation of inverse Radon transform (IRT) as the number of projections is enhanced. The value of PSNR has been found to increase from 8.20 to 24.53 dB as the number of projections is raised from 5 to 180 for head phantom. (author)

  5. Increasing Underrepresented Students in Geophysics and Planetary Science Through the Educational Internship in Physical Sciences (EIPS)

    Science.gov (United States)

    Terrazas, S.; Olgin, J. G.; Enriquez, F.

    2017-12-01

    The number of underrepresented minorities pursuing STEM fields, specifically in the sciences, has declined in recent times. In response, the Educational Internship in Physical Sciences (EIPS), an undergraduate research internship program in collaboration with The University of Texas at El Paso (UTEP) Geological Sciences Department and El Paso Community College (EPCC), was created; providing a mentoring environment so that students can actively engage in science projects with professionals in their field so as to gain the maximum benefits in an academic setting. This past year, interns participated in planetary themed projects which exposed them to the basics of planetary geology, and worked on projects dealing with introductory digital image processing and synthesized data on two planetary bodies; Pluto and Enceladus respectively. Interns harnessed and built on what they have learned through these projects, and directly applied it in an academic environment in solar system astronomy classes at EPCC. Since the majority of interns are transfer students or alums from EPCC, they give a unique perspective and dimension of interaction; giving them an opportunity to personally guide and encourage current students there on available STEM opportunities. The goal was to have interns gain experience in planetary geology investigations and networking with professionals in the field; further promoting their interests and honing their abilities for future endeavors in planetary science. The efficacy of these activities toward getting interns to pursue STEM careers, enhance their education in planetary science, and teaching key concepts in planetary geophysics are demonstrated in this presentation.

  6. The Age-ility Project (Phase 1): Structural and functional imaging and electrophysiological data repository.

    Science.gov (United States)

    Karayanidis, Frini; Keuken, Max C; Wong, Aaron; Rennie, Jaime L; de Hollander, Gilles; Cooper, Patrick S; Ross Fulham, W; Lenroot, Rhoshel; Parsons, Mark; Phillips, Natalie; Michie, Patricia T; Forstmann, Birte U

    2016-01-01

    Our understanding of the complex interplay between structural and functional organisation of brain networks is being advanced by the development of novel multi-modal analyses approaches. The Age-ility Project (Phase 1) data repository offers open access to structural MRI, diffusion MRI, and resting-state fMRI scans, as well as resting-state EEG recorded from the same community participants (n=131, 15-35 y, 66 male). Raw imaging and electrophysiological data as well as essential demographics are made available via the NITRC website. All data have been reviewed for artifacts using a rigorous quality control protocol and detailed case notes are provided. Copyright © 2015. Published by Elsevier Inc.

  7. Design of the PET–MR system for head imaging of the DREAM Project

    International Nuclear Information System (INIS)

    González, A.J.; Conde, P.; Hernández, L.; Herrero, V.; Moliner, L.; Monzó, J.M.; Orero, A.; Peiró, A.; Rodríguez-Álvarez, M.J.; Ros, A.; Sánchez, F.; Soriano, A.; Vidal, L.F.; Benlloch, J.M.

    2013-01-01

    In this paper we describe the overall design of a PET–MR system for head imaging within the framework of the DREAM Project as well as the first detector module tests. The PET system design consists of 4 rings of 16 detector modules each and it is expected to be integrated in a head dedicated radio frequency coil of an MR scanner. The PET modules are based on monolithic LYSO crystals coupled by means of optical devices to an array of 256 Silicon Photomultipliers. These types of crystals allow to preserve the scintillation light distribution and, thus, to recover the exact photon impact position with the proper characterization of such a distribution. Every module contains 4 Application Specific Integrated Circuits (ASICs) which return detailed information of several light statistical momenta. The preliminary tests carried out on this design and controlled by means of ASICs have shown promising results towards the suitability of hybrid PET–MR systems

  8. A Photometric Stereo Using Re-Projected Images for Active Stereo Vision System

    Directory of Open Access Journals (Sweden)

    Keonhwa Jung

    2017-10-01

    Full Text Available In optical 3D shape measurement, stereo vision with structured light can measure 3D scan data with high accuracy and is used in many applications, but fine surface detail is difficult to obtain. On the other hand, photometric stereo can capture surface details but has disadvantages, in that its 3D data accuracy drops and it requires multiple light sources. When the two measurement methods are combined, more accurate 3D scan data and detailed surface features can be obtained at the same time. In this paper, we present a 3D optical measurement technique that uses re-projection of images to implement photometric stereo without an external light source. 3D scan data is enhanced by combining normal vector from this photometric stereo method, and the result is evaluated with the ground truth.

  9. Multiscale Geophysical Characterization of Weathering Fronts Along a Climate and Vegetation Gradient in Chile

    Science.gov (United States)

    Dal Bo, I.; Klotzsche, A.; Schaller, M.; Ehlers, T. A.; Vereecken, H.; Van Der Kruk, J.

    2017-12-01

    Understanding how weathering processes act is non-trivial. Direct methods are spatially restricted, time consuming, and expensive. Here, we show how to upscale and extend the point-scale layering information from dug pits deploying a multi-scale geophysical approach. Many studies have recently shown the potential of geophysics in bridging the gap between scales, although limited to specific environments. We applied Electromagnetic Induction (EMI), Ground Penetrating Radar (GPR), and Electrical Resistivity Tomography (ERT) in four study areas separated by 1600 km in the Chilean Coastal Cordillera, and ranging from the arid Atacama Desert in the north and temperate forests in the south. The main goals were to understand how the soil profile and the weathering front vary: 1) from north to south along these gradients, 2) in north- and south-facing hillslopes, and 3) within a single hillslope. We measured at the large-scale (EMI), at the profile scale (EMI, ERT, and GPR), and at the point-scale (GPR). The total length of the EMI, GPR and ERT measurements was 28.95 km, 3.67 km, and 0.27 km. GPR wide angle reflection and refraction measurements were the link between ground-truth data and geophysics. The low electrical conductivity (EC) regime limited the applicability of the EMI and ERT. However, still relative patterns of apparent electrical conductivity (ECa) from EMI could be used. Generally, ECa increased moving uphill and from north to south. Due to the low EC values in the study areas, GPR could image several reflections up to 8 m depth partially confirmed by the pit layering. Thicker layers on GPR profiles were present going from north to south and in the bottom-mid part of the hillslopes, as confirmed by ground-truth data. The main recognizable feature in the GPR profiles was the transition between B and C horizon. Here, hyperbolic-shape signatures were observed that probably were related to the presence of heterogeneities. The soil pits showed deeper layers in

  10. Geophysical Exploration Technologies for the Deep Lithosphere Research: An Education Materials for High School Students

    Science.gov (United States)

    Xu, H.; Xu, C.; Luo, S.; Chen, H.; Qin, R.

    2012-12-01

    The science of Geophysics applies the principles of physics to study of the earth. Geophysical exploration technologies include the earthquake seismology, the seismic reflection and refraction methods, the gravity method, the magnetic method and the magnetotelluric method, which are used to measure the interior material distribution, their structure and the tectonics in the lithosphere of the earth. Part of the research project in SinoProbe-02-06 is to develop suitable education materials for carton movies targeting the high school students and public. The carton movies include five parts. The first part includes the structures of the earth's interior and variation in their physical properties that include density, p-wave, s-wave and so on, which are the fundamentals of the geophysical exploration technologies. The second part includes the seismology that uses the propagation of elastic waves through the earth to study the structure and the material distribution of the earth interior. It can be divided into earthquake seismology and artifice seismics commonly using reflection and refraction. The third part includes the magnetic method. Earth's magnetic field (also known as the geomagnetic field)extends from the Earth's inner core to where it meets the solar wind, a stream of energetic particles emanating from the Sun. The aim of magnetic survey is to investigate subsurface geology on the basis of anomalies in the Earth's magnetic field resulting from the magnetic properties of the underlying rocks. The magnetic method in the lithosphere attempts to use magnetic disturbance to analyse the regional geological structure and the magnetic boundaries of the crust. The fourth part includes the gravity method. A gravity anomaly results from the inhomogeneous distribution of density of the Earth. Usually gravity anomalies contain superposed anomalies from several sources. The long wave length anomalies due to deep density contrasts are called regional anomalies. They are

  11. Diaphragm motion quantification in megavoltage cone-beam CT projection images.

    Science.gov (United States)

    Chen, Mingqing; Siochi, R Alfredo

    2010-05-01

    To quantify diaphragm motion in megavoltage (MV) cone-beam computed tomography (CBCT) projections. User identified ipsilateral hemidiaphragm apex (IHDA) positions in two full exhale and inhale frames were used to create bounding rectangles in all other frames of a CBCT scan. The bounding rectangle was enlarged to create a region of interest (ROI). ROI pixels were associated with a cost function: The product of image gradients and a gradient direction matching function for an ideal hemidiaphragm determined from 40 training sets. A dynamic Hough transform (DHT) models a hemidiaphragm as a contour made of two parabola segments with a common vertex (the IHDA). The images within the ROIs are transformed into Hough space where a contour's Hough value is the sum of the cost function over all contour pixels. Dynamic programming finds the optimal trajectory of the common vertex in Hough space subject to motion constraints between frames, and an active contour model further refines the result. Interpolated ray tracing converts the positions to room coordinates. Root-mean-square (RMS) distances between these positions and those resulting from an expert's identification of the IHDA were determined for 21 Siemens MV CBCT scans. Computation time on a 2.66 GHz CPU was 30 s. The average craniocaudal RMS error was 1.38 +/- 0.67 mm. While much larger errors occurred in a few near-sagittal frames on one patient's scans, adjustments to algorithm constraints corrected them. The DHT based algorithm can compute IHDA trajectories immediately prior to radiation therapy on a daily basis using localization MVCBCT projection data. This has potential for calibrating external motion surrogates against diaphragm motion.

  12. Evaluation of geophysical borehole studies

    International Nuclear Information System (INIS)

    Brotzen, O.; Duran, O.; Magnusson, K.Aa.

    Four studies concerning geophysical investigations and TV inspection in boreholes in connection with KBS studies at Finnsjoe, Karlshamn, Kraakemaala and Stripa and PRAV's studies at Studsvik have been evaluated. This has led to proposals concerning the choice of instruments and methods for future studies and a review of future work required. The evaluation has shown that the following borehole measurements are of primary interest in the continued work: Determinations of temperature and resistivity of the borehole liquid, resistance and resistivity measurements, SP, Sonic, Caliper and VLF. TV inspection, IP and gamma-gamma should also be included in the arsenal of available test methods.(author)

  13. Stochastic resonance for exploration geophysics

    OpenAIRE

    Omerbashich, Mensur

    2008-01-01

    Stochastic resonance (SR) is a phenomenon in which signal to noise (SN) ratio gets improved by noise addition rather than removal as envisaged classically. SR was first claimed in climatology a few decades ago and then in other disciplines as well. The same as it is observed in natural systems, SR is used also for allowable SN enhancements at will. Here I report a proof of principle that SR can be useful in exploration geophysics. For this I perform high frequency GaussVanicek variance spectr...

  14. Geophysical analysis for the Ada Tepe region (Bulgaria) - case study

    Science.gov (United States)

    Trifonova, Petya; Metodiev, Metodi; Solakov, Dimcho; Simeonova, Stela; Vatseva, Rumiana

    2013-04-01

    According to the current archeological investigations Ada Tepe is the oldest gold mine in Europe with Late Bronze and Early Iron age. It is a typical low-sulfidation epithermal gold deposit and is hosted in Maastrichtian-Paleocene sedimentary rocks above a detachment fault contact with underlying Paleozoic metamorphic rocks. Ada Tepe (25o.39'E; 41o.25'N) is located in the Eastern Rhodope unit. The region is highly segmented despite the low altitude (470-750 m) due to widespread volcanic and sediment rocks susceptible to torrential erosion during the cold season. Besides the thorough geological exploration focused on identifying cost-effective stocks of mineral resources, a detailed geophysical analysis concernig diferent stages of the gold extraction project was accomplished. We present the main results from the geophysical investigation aimed to clarify the complex seismotectonic setting of the Ada Tepe site region. The overall study methodology consists of collecting, reviewing and estimating geophysical and seismological information to constrain the model used for seismic hazard assessment of the area. Geophysical information used in the present work consists of gravity, geomagnetic and seismological data. Interpretation of gravity data is applied to outline the axes of steep gravity transitions marked as potential axes of faults, flexures and other structures of dislocation. Direct inverse techniques are also utilized to estimate the form and depth of anomalous sources. For the purposes of seismological investigation of the Ada Tepe site region an earthquake catalogue is compiled for the time period 510BC - 2011AD. Statistical parameters of seismicity - annual seismic rate parameter, ?, and the b-value of the Gutenberg-Richter exponential relation for Ada Tepe site region, are estimated. All geophysical datasets and derived results are integrated using GIS techniques ensuring interoperability of data when combining, processing and visualizing obtained

  15. Environmental geophysics and geochemistry for contamination mapping and monitoring 1

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tai Sup; Lee, Sang Kyu; Hong, Young Kook [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of); and others

    1995-12-01

    This study aims to provide the technologies which can be practically used for contamination mapping and monitoring. To accomplish this goal, the geophysical and geochemical expertise and techniques commonly used in the mineral resources exploration are employed. In the first year of the three-year-long project, the purpose of the study is to introduce the optimum methodologies among the geophysical and geochemical techniques to tackle the various cases of environmental contamination. To achieve the purpose, case studies of the developed countries were surveyed and analyzed through the various kinds of literatures. The followings are categorized to be solved by geophysical methods: 1) delineation of water system pollution by acid mine drainage and distributions of waste rocks in the closed mine area, 2) defining boundaries of subsurface contamination due to oil seepage, 3) zoning of sea water intrusion in the seashore or subsurface geology highly containing salt, 4) locating of buried metallic wastes such as pipes and drums which can cause the secondary pollution by corrosion, and 5) outlining of the subsurface area polluted by leachate from the landfill. To experiment the above items, various geophysical methods were applied to the corresponding test sites. From these experiments, the applicabilities of the respective geophysical method were analyzed, and the optimum methods were derived for the various pollution types. Furthermore, electric and electromagnetic surveys data processing software were developed to quantitatively interpret and highly resolve the geology. The environmental assignments which can be solved by geochemical methods include: 1) drainage pollution by coal mine effluents, 2)subsurface contamination of oil-spill, 3) sea water intrusion, 4) dispersion of toxic heavy metallic elements in the metal mines, and 5) radon environmental geochemistry. The appropriate test sites for applying the geochemical methods were selected. (Abstract Truncated)

  16. Institute of Geophysics, Planetary Physics, and Signatures

    Data.gov (United States)

    Federal Laboratory Consortium — The Institute of Geophysics, Planetary Physics, and Signatures at Los Alamos National Laboratory is committed to promoting and supporting high quality, cutting-edge...

  17. Short Project-Based Learning with MATLAB Applications to Support the Learning of Video-Image Processing

    Science.gov (United States)

    Gil, Pablo

    2017-10-01

    University courses concerning Computer Vision and Image Processing are generally taught using a traditional methodology that is focused on the teacher rather than on the students. This approach is consequently not effective when teachers seek to attain cognitive objectives involving their students' critical thinking. This manuscript covers the development, implementation and assessment of a short project-based engineering course with MATLAB applications Multimedia Engineering being taken by Bachelor's degree students. The principal goal of all course lectures and hands-on laboratory activities was for the students to not only acquire image-specific technical skills but also a general knowledge of data analysis so as to locate phenomena in pixel regions of images and video frames. This would hopefully enable the students to develop skills regarding the implementation of the filters, operators, methods and techniques used for image processing and computer vision software libraries. Our teaching-learning process thus permits the accomplishment of knowledge assimilation, student motivation and skill development through the use of a continuous evaluation strategy to solve practical and real problems by means of short projects designed using MATLAB applications. Project-based learning is not new. This approach has been used in STEM learning in recent decades. But there are many types of projects. The aim of the current study is to analyse the efficacy of short projects as a learning tool when compared to long projects during which the students work with more independence. This work additionally presents the impact of different types of activities, and not only short projects, on students' overall results in this subject. Moreover, a statistical study has allowed the author to suggest a link between the students' success ratio and the type of content covered and activities completed on the course. The results described in this paper show that those students who took part

  18. The University of Texas Institute for Geophysics Marine Geology and Geophysics Field Course

    Science.gov (United States)

    Duncan, D.; Davis, M. B.; Goff, J. A.; Gulick, S. P. S.; McIntosh, K. D.; Saustrup, S., Sr.

    2014-12-01

    The University of Texas Institute for Geophysics, part of the Jackson School of Geosciences, annually offers a three-week marine geology and geophysics field course during the spring-summer intersession. The course provides hands-on instruction and training for graduate and upper-level undergraduate students in high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, several types of sediment coring, grab sampling, and the sedimentology of resulting seabed samples. Students participate in an initial three days of classroom instruction designed to communicate geological context of the field area along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work. Our field sites at Port Aransas, and Galveston, TX, and Grand Isle, LA, provide ideal locations for students to investigate coastal processes of the Gulf Coast and continental shelf through application of geophysical techniques in an exploratory mode. At sea, students assist with survey design and instrumentation set up while learning about acquisition parameters, data quality control, trouble-shooting, and safe instrument deployment and retrieval. In teams of four, students work in onshore field labs preparing sediment samples for particle size analysis and data processing. During the course's final week, teams return to the classroom where they integrate, interpret, and visualize data in a final project using industry-standard software such as Echos, Landmark, Caris, and Fledermaus. The course concludes with a series of final presentations and discussions in which students examine geologic history and/or sedimentary processes represented by the Gulf Coast continental shelf with academic and industry supporters. Students report a greater understanding of marine geology and geophysics through the course's intensive, hands-on, team approach and low instructor to student ratio (sixteen

  19. EAST93: Geophysical traverse from the Transantarctic Mountains to the Wilkes Basin, East Antarctica

    Science.gov (United States)

    ten Brink, Uri S.; Bannister, Stephen

    1995-01-01

    The East Antarctic Seismic Traverse (EAST93) was a geophysical traverse designed to image the bedrock under the East Antarctic ice cap. The traverse started 10 km west of the Taylor Dome drill site and 25 km west of the exposed bedrock of the Transantarctic Mountains at Lashly Mt. and ended 323 km west of the drill site over the Wilkes subglacial basin (Fig. 1). The traverse was located subparallel to latitude 78° S starting 30-50 km north of the Victoria Land Traverse (1958-1959). It was carried out jointly by the U.S. Geological Survey and Stanford University, U.S.A., together with the Institute of Geological and Nuclear Sciences, and Victoria University, New Zealand, during December 1993 and January 1994. The geophysical traverse included 236 km of multichannel seismic reflection data at 150 m shot intervals, 312.5 km of gravity data collected at intervals of 2.1 km, 312.5 km of magnetic data (total field intensity) collected at average intervals of 0.5 km, and 205 km of ground penetrating radar at intervals of 77 m. Relative locations and elevations of the entire traverse were measured at intervals of 150 m by traditional surveying methods, and tied to three absolute locations measured by the Global Positioning System (GPS). EAST93 is the first large-scale geophysical traverse on the polar plateau to our knowledge since the early 1960s. As such, the experiment presented several logistical challenges: (1) how to collect regional seismic profiles during the short Antarctic summer; (2) how to keep the scientific instruments running with minimal protection in harsh conditions; and (3) how to combine daily moves of camp with full days of work. The scientific and logistical aspects of the project proceeded, in general, according to plan despite the harsh conditions and our lack of previous experience on the polar plateau. Two unanticipated problems affected the progress of the work: the strong wind which slowed seismic acquisition, and the break-down of one of the

  20. Developing priority criteria for magnetic resonance imaging: results from the Western Canada Waiting List project

    International Nuclear Information System (INIS)

    Hadorn, D.C.

    2002-01-01

    The Western Canada Waiting List (WCWL) Project is a federally funded partnership of 19 organizations, including medical associations, health authorities, ministries of health and research organizations, that was created to develop tools to assist in assessing the relative urgency and priority of patients on waiting lists. The WCWL panel on magnetic resonance imaging (MRI) was 1 of 5 panels constituted under this project. The panel developed and tested a set of standardized clinical criteria for setting priorities among patients awaiting MRI. The criteria were applied to 407 patients in the 4 western provinces. Regression analysis was used to determine the set of criteria weights that collectively best predicted clinicians' overall ratings of patients' urgency for MRI. Reliability was assessed using clinicians' ratings of 6 hypothetical paper cases. The resulting weighted criteria accounted for about two-fifths of the observed variance in overall urgency ratings (R 2 = 39.9%). The panel then modified the criteria on the basis of regression results and clinical judgment. Most of the revised criteria items showed poor inter-rater reliability, but test-retest reliability (over a 2-month interval) was relatively good. Criteria items requiring probability judgments were a challenge for clinicians. Further development and testing of the tool appears warranted, although considerable question remains concerning the utility of priority criteria for MRI and other diagnostic services. (author)

  1. A 3D Kinematic Measurement of Knee Prosthesis Using X-ray Projection Images

    Science.gov (United States)

    Hirokawa, Shunji; Ariyoshi, Shogo; Hossain, Mohammad Abrar

    We have developed a technique for estimating 3D motion of knee prosthesis from its 2D perspective projections. As Fourier descriptors were used for compact representation of library templates and contours extracted from the prosthetic X-ray images, the entire silhouette contour of each prosthetic component was required. This caused such a problem as our algorithm did not function when the silhouettes of tibio and femoral components overlapped with each other. Here we planned a novel method to overcome it; which was processed in two steps. First, the missing part of silhouette contour due to overlap was interpolated using a free-formed curvature such as Bezier. Then the first step position/orientation estimation was performed. In the next step, a clipping window was set in the projective coordinate so as to separate the overlapped silhouette drawn using the first step estimates. After that the localized library whose templates were clipped in shape was prepared and the second step estimation was performed. Computer model simulation demonstrated sufficient accuracies of position/orientation estimation even for overlapped silhouettes; equivalent to those without overlap.

  2. High-speed technique based on a parallel projection correlation procedure for digital image correlation

    Science.gov (United States)

    Zaripov, D. I.; Renfu, Li

    2018-05-01

    The implementation of high-efficiency digital image correlation methods based on a zero-normalized cross-correlation (ZNCC) procedure for high-speed, time-resolved measurements using a high-resolution digital camera is associated with big data processing and is often time consuming. In order to speed-up ZNCC computation, a high-speed technique based on a parallel projection correlation procedure is proposed. The proposed technique involves the use of interrogation window projections instead of its two-dimensional field of luminous intensity. This simplification allows acceleration of ZNCC computation up to 28.8 times compared to ZNCC calculated directly, depending on the size of interrogation window and region of interest. The results of three synthetic test cases, such as a one-dimensional uniform flow, a linear shear flow and a turbulent boundary-layer flow, are discussed in terms of accuracy. In the latter case, the proposed technique is implemented together with an iterative window-deformation technique. On the basis of the results of the present work, the proposed technique is recommended to be used for initial velocity field calculation, with further correction using more accurate techniques.

  3. Improved application of independent component analysis to functional magnetic resonance imaging study via linear projection techniques.

    Science.gov (United States)

    Long, Zhiying; Chen, Kewei; Wu, Xia; Reiman, Eric; Peng, Danling; Yao, Li

    2009-02-01

    Spatial Independent component analysis (sICA) has been widely used to analyze functional magnetic resonance imaging (fMRI) data. The well accepted implicit assumption is the spatially statistical independency of intrinsic sources identified by sICA, making the sICA applications difficult for data in which there exist interdependent sources and confounding factors. This interdependency can arise, for instance, from fMRI studies investigating two tasks in a single session. In this study, we introduced a linear projection approach and considered its utilization as a tool to separate task-related components from two-task fMRI data. The robustness and feasibility of the method are substantiated through simulation on computer data and fMRI real rest data. Both simulated and real two-task fMRI experiments demonstrated that sICA in combination with the projection method succeeded in separating spatially dependent components and had better detection power than pure model-based method when estimating activation induced by each task as well as both tasks.

  4. Comparison of pure and hybrid iterative reconstruction techniques with conventional filtered back projection: Image quality assessment in the cervicothoracic region

    International Nuclear Information System (INIS)

    Katsura, Masaki; Sato, Jiro; Akahane, Masaaki; Matsuda, Izuru; Ishida, Masanori; Yasaka, Koichiro; Kunimatsu, Akira; Ohtomo, Kuni

    2013-01-01

    Objectives: To evaluate the impact on image quality of three different image reconstruction techniques in the cervicothoracic region: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP). Methods: Forty-four patients underwent unenhanced standard-of-care clinical computed tomography (CT) examinations which included the cervicothoracic region with a 64-row multidetector CT scanner. Images were reconstructed with FBP, 50% ASIR-FBP blending (ASIR50), and MBIR. Two radiologists assessed the cervicothoracic region in a blinded manner for streak artifacts, pixilated blotchy appearances, critical reproduction of visually sharp anatomical structures (thyroid gland, common carotid artery, and esophagus), and overall diagnostic acceptability. Objective image noise was measured in the internal jugular vein. Data were analyzed using the sign test and pair-wise Student's t-test. Results: MBIR images had significant lower quantitative image noise (8.88 ± 1.32) compared to ASIR images (18.63 ± 4.19, P 0.9 for ASIR vs. FBP for both readers). MBIR images were all diagnostically acceptable. Unique features of MBIR images included pixilated blotchy appearances, which did not adversely affect diagnostic acceptability. Conclusions: MBIR significantly improves image noise and streak artifacts of the cervicothoracic region over ASIR and FBP. MBIR is expected to enhance the value of CT examinations for areas where image noise and streak artifacts are problematic

  5. Image quality of microcalcifications in digital breast tomosynthesis: Effects of projection-view distributions

    International Nuclear Information System (INIS)

    Lu, Yao; Chan, Heang-Ping; Wei, Jun; Goodsitt, Mitch; Carson, Paul L.; Hadjiiski, Lubomir; Schmitz, Andrea; Eberhard, Jeffrey W.; Claus, Bernhard E. H.

    2011-01-01

    Purpose: To analyze the effects of projection-view (PV) distribution on the contrast and spatial blurring of microcalcifications on the tomosynthesized slices (X-Y plane) and along the depth (Z) direction for the same radiation dose in digital breast tomosynthesis (DBT). Methods: A GE GEN2 prototype DBT system was used for acquisition of DBT scans. The system acquires PV images from 21 angles in 3 deg. increments over a ±30 deg. range. From these acquired PV images, the authors selected six subsets of PV images to simulate DBT of different angular ranges and angular increments. The number of PV images in each subset was fixed at 11 to simulate a constant total dose. These different PV distributions were subjectively divided into three categories: uniform group, nonuniform central group, and nonuniform extreme group with different angular ranges and angular increments. The simultaneous algebraic reconstruction technique (SART) was applied to each subset to reconstruct the DBT slices. A selective diffusion regularization method was employed to suppress noise. The image quality of microcalcifications in the reconstructed DBTs with different PV distributions was compared using the DBT scans of an American College of Radiology phantom and three human subjects. The contrast-to-noise ratio (CNR) and the full width at half maximum (FWHM) of the line profiles of microcalcifications within their in-focus DBT slices (parallel to detector plane) and the FWHMs of the interplane artifact spread function (ASF) in the Z-direction (perpendicular to detector plane) were used as image quality measures. Results: The results indicate that DBT acquired with a large angular range or, for an equal angular range,with a large fraction of PVs at large angles yielded superior ASF with smaller FWHM in the Z-direction. PV distributions with a narrow angular range or a large fraction of PVs at small angles had stronger interplane artifacts. In the X-Y focal planes, the effect of PV

  6. Objective and expert-independent validation of retinal image registration algorithms by a projective imaging distortion model.

    Science.gov (United States)

    Lee, Sangyeol; Reinhardt, Joseph M; Cattin, Philippe C; Abràmoff, Michael D

    2010-08-01

    Fundus camera imaging of the retina is widely used to diagnose and manage ophthalmologic disorders including diabetic retinopathy, glaucoma, and age-related macular degeneration. Retinal images typically have a limited field of view, and multiple images can be joined together using an image registration technique to form a montage with a larger field of view. A variety of methods for retinal image registration have been proposed, but evaluating such methods objectively is difficult due to the lack of a reference standard for the true alignment of the individual images that make up the montage. A method of generating simulated retinal images by modeling the geometric distortions due to the eye geometry and the image acquisition process is described in this paper. We also present a validation process that can be used for any retinal image registration method by tracing through the distortion path and assessing the geometric misalignment in the coordinate system of the reference standard. The proposed method can be used to perform an accuracy evaluation over the whole image, so that distortion in the non-overlapping regions of the montage components can be easily assessed. We demonstrate the technique by generating test image sets with a variety of overlap conditions and compare the accuracy of several retinal image registration models. Copyright 2010 Elsevier B.V. All rights reserved.

  7. Use of the geometric mean of opposing planar projections in pre-reconstruction restoration of SPECT images

    International Nuclear Information System (INIS)

    Boulfelfel, D.; Rangayyan, R.M.; Hahn, L.J.; Kloiber, R.

    1992-01-01

    This paper presents a restoration scheme for single photon emission computed tomography (SPECT) images that performs restoration before reconstruction (pre-reconstruction restoration) from planar (projection) images. In this scheme, the pixel-by-pixel geometric mean of each pair of opposing (conjugate) planar projections is computed prior to the reconstruction process. The averaging process is shown to help in making the degradation phenomenon less dependent on the distance of each point of the object from the camera. The restoration filters investigated are the Wiener and power spectrum equalization filters. (author)

  8. Reconstruction of computed tomographic image from a few x-ray projections by means of accelerative gradient method

    International Nuclear Information System (INIS)

    Kobayashi, Fujio; Yamaguchi, Shoichiro

    1982-01-01

    A method of the reconstruction of computed tomographic images was proposed to reduce the exposure dose to X-ray. The method is the small number of X-ray projection method by accelerative gradient method. The procedures of computation are described. The algorithm of these procedures is simple, the convergence of the computation is fast, and the required memory capacity is small. Numerical simulation was carried out to conform the validity of this method. A sample of simple shape was considered, projection data were given, and the images were reconstructed from 6 views. Good results were obtained, and the method is considered to be useful. (Kato, T.)

  9. Exact fan-beam image reconstruction algorithm for truncated projection data acquired from an asymmetric half-size detector

    International Nuclear Information System (INIS)

    Leng Shuai; Zhuang Tingliang; Nett, Brian E; Chen Guanghong

    2005-01-01

    In this paper, we present a new algorithm designed for a specific data truncation problem in fan-beam CT. We consider a scanning configuration in which the fan-beam projection data are acquired from an asymmetrically positioned half-sized detector. Namely, the asymmetric detector only covers one half of the scanning field of view. Thus, the acquired fan-beam projection data are truncated at every view angle. If an explicit data rebinning process is not invoked, this data acquisition configuration will reek havoc on many known fan-beam image reconstruction schemes including the standard filtered backprojection (FBP) algorithm and the super-short-scan FBP reconstruction algorithms. However, we demonstrate that a recently developed fan-beam image reconstruction algorithm which reconstructs an image via filtering a backprojection image of differentiated projection data (FBPD) survives the above fan-beam data truncation problem. Namely, we may exactly reconstruct the whole image object using the truncated data acquired in a full scan mode (2π angular range). We may also exactly reconstruct a small region of interest (ROI) using the truncated projection data acquired in a short-scan mode (less than 2π angular range). The most important characteristic of the proposed reconstruction scheme is that an explicit data rebinning process is not introduced. Numerical simulations were conducted to validate the new reconstruction algorithm

  10. Projectables

    DEFF Research Database (Denmark)

    Rasmussen, Troels A.; Merritt, Timothy R.

    2017-01-01

    CNC cutting machines have become essential tools for designers and architects enabling rapid prototyping, model-building and production of high quality components. Designers often cut from new materials, discarding the irregularly shaped remains. We introduce ProjecTables, a visual augmented...... reality system for interactive packing of model parts onto sheet materials. ProjecTables enables designers to (re)use scrap materials for CNC cutting that would have been previously thrown away, at the same time supporting aesthetic choices related to wood grain, avoiding surface blemishes, and other...... relevant material properties. We conducted evaluations of ProjecTables with design students from Aarhus School of Architecture, demonstrating that participants could quickly and easily place and orient model parts reducing material waste. Contextual interviews and ideation sessions led to a deeper...

  11. A 3D imaging system integrating photoacoustic and fluorescence orthogonal projections for anatomical, functional and molecular assessment of rodent models

    Science.gov (United States)

    Brecht, Hans P.; Ivanov, Vassili; Dumani, Diego S.; Emelianov, Stanislav Y.; Anastasio, Mark A.; Ermilov, Sergey A.

    2018-03-01

    We have developed a preclinical 3D imaging instrument integrating photoacoustic tomography and fluorescence (PAFT) addressing known deficiencies in sensitivity and spatial resolution of the individual imaging components. PAFT is designed for simultaneous acquisition of photoacoustic and fluorescence orthogonal projections at each rotational position of a biological object, enabling direct registration of the two imaging modalities. Orthogonal photoacoustic projections are utilized to reconstruct large (21 cm3 ) volumes showing vascularized anatomical structures and regions of induced optical contrast with spatial resolution exceeding 100 µm. The major advantage of orthogonal fluorescence projections is significant reduction of background noise associated with transmitted or backscattered photons. The fluorescence imaging component of PAFT is used to boost detection sensitivity by providing low-resolution spatial constraint for the fluorescent biomarkers. PAFT performance characteristics were assessed by imaging optical and fluorescent contrast agents in tissue mimicking phantoms and in vivo. The proposed PAFT technology will enable functional and molecular volumetric imaging using fluorescent biomarkers, nanoparticles, and other photosensitive constructs mapped with high fidelity over robust anatomical structures, such as skin, central and peripheral vasculature, and internal organs.

  12. Multi-detector and systematic imaging system designed and developed within the New AGLAE project

    International Nuclear Information System (INIS)

    Pichon, L.; Pacheco, C.; Moignard, B.; Lemasson, Q.; Guillou, T.; Walter, Ph

    2013-01-01

    Full text: The New AGLAE project aims to establish a world-class facility for non invasive analysis of Cultural Heritage materials. One of the objectives of the New AGLAE project is to increase the x-ray measurement detection, enabling to reduce the beam intensity thus the interaction with sensitive artworks by a ten. Multidisciplinary, the New AGLAE project will provide an exceptional and multipurpose beam line with a performance in spatial resolution, beam stability and a capability of multi-particle detection much higher than for the previous facility. The New AGLAE will give fundamental elements for the understanding of the structure of materials, their composition, properties, and change over time. One of the objectives of this project is to design and set up a new data acquisition system. To reach that purpose, the surface and the number of PIXE detectors have been increased. Indeed, a 10 mm 2 and a 30 mm 3 Si(Li) detectors respectively dedicated to low and high energy measurements, were replaced by a cluster of five 50 mm 2 S.D.D. detectors. If this multi detector enables to decrease the intensity of the incident beam by one order of magnitude, involving less irradiation during the analysis, it can also provide large and/or fast maps. So as to digital the preamp pulses obtained from the detectors, a custom Digital X-ray Processor provides both digital data and control signals compatible to a multiparameter multichannel system. This multiparameter system saves each event from x-ray, gamma and particle detectors and simultaneously the X, Y positions of the beam on the sample as a list file. Furthermore, to draw several-cm-sized maps with a 20/40μm resolution, the scanning of the area originally combines a fast vertical magnetic deflection of the beam and a mechanical movement of the target. To process the data, several homemade software have been developed or updated so as to rebuild any matrix of spectra, to re-bin maps, to process a series of single spectra

  13. Multidetector CT evaluation of central airways stenoses: Comparison of virtual bronchoscopy, minimal-intensity projection, and multiplanar reformatted images

    Directory of Open Access Journals (Sweden)

    Dinesh K Sundarakumar

    2011-01-01

    Full Text Available Aims: To evaluate the diagnostic utility of virtual bronchoscopy, multiplanar reformatted images, and minimal-intensity projection in assessing airway stenoses. Settings and Design: It was a prospective study involving 150 patients with symptoms of major airway disease. Materials and Methods: Fifty-six patients were selected for analysis based on the detection of major airway lesions on fiber-optic bronchoscopy (FB or routine axial images. Comparisons were made between axial images, virtual bronchoscopy (VB, minimal-intensity projection (minIP, and multiplanar reformatted (MPR images using FB as the gold standard. Lesions were evaluated in terms of degree of airway narrowing, distance from carina, length of the narrowed segment and visualization of airway distal to the lesion. Results: MPR images had the highest degree of agreement with FB (Κ = 0.76 in the depiction of degree of narrowing. minIP had the least degree of agreement with FB (Κ = 0.51 in this regard. The distal visualization was best on MPR images (84.2%, followed by axial images (80.7%, whereas FB could visualize the lesions only in 45.4% of the cases. VB had the best agreement with FB in assessing the segment length (Κ = 0.62. Overall there were no statistically significant differences in the measurement of the distance from the carina in the axial, minIP, and MPR images. MPR images had the highest overall degree of confidence, namely, 70.17% (n = 40. Conclusion: Three-dimensional reconstruction techniques were found to improve lesion evaluation compared with axial images alone. The technique of MPR images was the most useful for lesion evaluation and provided additional information useful for surgical and airway interventions in tracheobronchial stenosis. minIP was useful in the overall depiction of airway anatomy.

  14. Back-Projection Imaging of extended, high-frequency pre-, co-, and post-eruptive seismicity at El Jefe Geyser, El Tatio Geyser Field, Chile

    Science.gov (United States)

    Kelly, C. L.; Lawrence, J. F.; Beroza, G. C.

    2017-12-01

    El Tatio Geyser Field in northern Chile is the third largest geyser field in the world. It is comprised of 3 basins that span 10 km x 10 km at an average elevation of 4250 m and contains at least 80 active geysers. Heavy tourist traffic and previous geothermal exploration make the field relatively non-pristine and ideal for performing minimally invasive geophysical experiments. We deployed a dense array of 51 L-28 3-component geophones (1-10 m spacing, corner frequency 4.5 Hz, 1000 Hz sample rate), and 6 Trillium 120 broadband seismometers (2-20 m spacing, long period corner 120 s, 500 Hz sample rate) in a 50 m x 50 m grid in the central Upper Geyser Basin (the largest basin in area at 5 km x 5 km) during October 2012 as part of a collaborative study of hydrothermal systems between Stanford University; U.C. Berkeley; U. of Chile, Santiago; U. of Tokyo; and the USGS. The seismic array was designed to target at El Jefe Geyser (EJG), a columnar geyser (eruption height 1-1.5 m) with a consistent periodic eruption cycle of 132 +/- 3 s. Seismicity at EJG was recorded continuously for 9 days during which 6000 total eruptions occurred. Excluding periods of high anthropogenic noise (i.e. tourist visits, field work), the array recorded 2000 eruptions that we use to create 4D time-lapse images of the evolution of seismic source locations before, during and after EJG eruptions. We use a new back-projection processing technique to locate geyser signals, which tend to be harmonic and diffuse in nature, during characteristic phases of the EJG eruption cycle. We obtain Vp and Vs from ambient-field tomography and estimates of P and S propagation from a hammer source recorded by the array. We use these velocities to back-project and correlate seismic signals from all available receiver-pairs to all potential source locations in a subsurface model assuming straight-line raypaths. We analyze results for individual and concurrent geyser sources throughout an entire EJG eruption cycle

  15. Responsibilities, opportunities and challenges in geophysical exploration

    International Nuclear Information System (INIS)

    Rytle, R.J.

    1982-01-01

    Geophysical exploration for engineering purposes is conducted to decrease the risk in encountering site uncertainties in construction of underground facilities. Current responsibilities, opportunities and challenges for those with geophysical expertise are defined. These include: replacing the squiggly line format, developing verification sites for method evaluations, applying knowledge engineering and assuming responsibility for crucial national problems involving rock mechanics expertise

  16. Microwave imaging

    CERN Document Server

    Pastorino, Matteo

    2010-01-01

    An introduction to the most relevant theoretical and algorithmic aspects of modern microwave imaging approaches Microwave imaging-a technique used in sensing a given scene by means of interrogating microwaves-has recently proven its usefulness in providing excellent diagnostic capabilities in several areas, including civil and industrial engineering, nondestructive testing and evaluation, geophysical prospecting, and biomedical engineering. Microwave Imaging offers comprehensive descriptions of the most important techniques so far proposed for short-range microwave imaging-in

  17. Application of integrated Landsat, geochemical and geophysical data in mineral exploration

    International Nuclear Information System (INIS)

    Conradsen, K.; Nilsson, G.; Thyrsted, T.; Gronlands Geologiske Undersogelse, Copenhagen, Denmark)

    1985-01-01

    In South Greenland (20000 sq. km) a remote sensing investigation is executed in connection with uranium exploration. The investigation includes analysis of Landsat data, conversion of geological, geochemical and geophysical data to image format compatible with Landsat images, and analysis of the total set of integrated data. The available geochemical data consisted of samples from 2000 sites, analyzed for U, K, Rb, Sr, Nb, Ga, Y, and Fe. The geophysical data comprised airborne gamma-spectrometric measurements and aeromagnetic data. The interpolation routines consisted of a kriging procedure for the geochemical data and a minimum curvature routine for the geophysical data. The analysis of the integrated data set is at a preliminary stage. As example a composite image showing Landsat channel 7, magnetic values, and Fe values as respectively intensity, hue and saturation is analyzed. It reveals alkaline intrusions and basaltic layers as anomalies while other anomalies cannot be accounted for on the basis of the present geological knowledge. 12 references

  18. Physics meets fine arts: a project-based learning path on infrared imaging

    Science.gov (United States)

    Bonanno, A.; Bozzo, G.; Sapia, P.

    2018-03-01

    Infrared imaging represents a noninvasive tool for cultural heritage diagnostics, based on the capability of IR radiation to penetrate the most external layers of different objects (as for example paintings), revealing hidden features of artworks. From an educational viewpoint, this diagnostic technique offers teachers the opportunity to address manifold topics pertaining to the physics and technology of electromagnetic radiation, with particular emphasis on the nature of color and its physical correlates. Moreover, the topic provides interesting interdisciplinary bridges towards the human sciences. In this framework, we present a hands-on learning sequence, suitable for both high school students and university freshmen, inspired by the project-based learning (PBL) paradigm, designed and implemented in the context of an Italian national project aimed at offering students the opportunity to participate in educational activities within a real working context. In a preliminary test we involved a group of 23 high school students while they were working as apprentices in the Laboratory of Applied Physics for Cultural Heritage (ArcheoLab) at the University of Calabria. Consistently with the PBL paradigm, students were given well-defined practical goals to be achieved. As final goals they were asked (i) to construct and to test a low cost device (based on a disused commercial camera) appropriate for performing educational-grade IR investigations on paintings, and (ii) to prepare a device working as a simple spectrometer (recycling the optical components of a disused video projector), suitable for characterizing various light sources in order to identify the most appropriate for infrared imaging. The proposed learning path has shown (in the preliminary test) to be effective in fostering students’ interest towards physics and its technological applications, especially because pupils perceived the context (i.e. physics applied to the protection and restoration of cultural

  19. High Resolution Mineral Mapping of the Oman Drilling Project Cores with Imaging Spectroscopy: Preliminary Results

    Science.gov (United States)

    Greenberger, R. N.; Ehlmann, B. L.; Kelemen, P. B.; Manning, C. E.; Teagle, D. A. H.; Harris, M.; Michibayashi, K.; Takazawa, E.

    2017-12-01

    The Oman Drilling Project provides an unprecedented opportunity to study the formation and alteration of oceanic crust and peridotite. Key to answering the main questions of the project are a characterization of the primary and secondary minerals present within the drill core and their spatial relationships. To that end, we used the Caltech imaging spectrometer system to scan the entire 1.5-km archive half of the core from all four gabbro and listvenite boreholes (GT1A, GT2A, GT3A, and BT1B) at 250 µm/pixel aboard the JAMSTEC Drilling Vessel Chikyu during the ChikyuOman core description campaign. The instrument measures the visible and shortwave infrared reflectance spectra of the rocks as a function of wavelength from 0.4 to 2.6 µm. This wavelength range is sensitive to many mineral groups, including hydrated minerals (phyllosilicates, zeolites, amorphous silica polytypes), carbonates, sulfates, and transition metals, most commonly iron-bearing mineralogies. To complete the measurements, the core was illuminated with a halogen light source and moved below the spectrometer at 1 cm/s by the Chikyu's Geotek track. Data are corrected and processed to reflectance using measurements of dark current and a spectralon calibration panel. The data provide a unique view of the mineralogy at high spatial resolution. Analysis of the images for complete downhole trends is ongoing. Thus far, a variety of minerals have been identified within their petrologic contexts, including but not limited to magnesite, dolomite, calcite, quartz (through an Si-OH absorption due to minor H2O), serpentine, chlorite, epidote, zeolites, mica (fuchsite), kaolinite, prehnite, gypsum, amphibole, and iron oxides. Further analysis will likely identify more minerals. Results include rapidly distinguishing the cations present within carbonate minerals and identifying minerals of volumetrically-low abundance within the matrix and veins of core samples. This technique, for example, accurately identifies

  20. Comparison of pure and hybrid iterative reconstruction techniques with conventional filtered back projection: Image quality assessment in the cervicothoracic region

    Energy Technology Data Exchange (ETDEWEB)

    Katsura, Masaki, E-mail: mkatsura-tky@umin.ac.jp [Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Sato, Jiro; Akahane, Masaaki; Matsuda, Izuru; Ishida, Masanori; Yasaka, Koichiro; Kunimatsu, Akira; Ohtomo, Kuni [Department of Radiology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan)

    2013-02-15

    Objectives: To evaluate the impact on image quality of three different image reconstruction techniques in the cervicothoracic region: model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP). Methods: Forty-four patients underwent unenhanced standard-of-care clinical computed tomography (CT) examinations which included the cervicothoracic region with a 64-row multidetector CT scanner. Images were reconstructed with FBP, 50% ASIR-FBP blending (ASIR50), and MBIR. Two radiologists assessed the cervicothoracic region in a blinded manner for streak artifacts, pixilated blotchy appearances, critical reproduction of visually sharp anatomical structures (thyroid gland, common carotid artery, and esophagus), and overall diagnostic acceptability. Objective image noise was measured in the internal jugular vein. Data were analyzed using the sign test and pair-wise Student's t-test. Results: MBIR images had significant lower quantitative image noise (8.88 ± 1.32) compared to ASIR images (18.63 ± 4.19, P < 0.01) and FBP images (26.52 ± 5.8, P < 0.01). Significant improvements in streak artifacts of the cervicothoracic region were observed with the use of MBIR (P < 0.001 each for MBIR vs. the other two image data sets for both readers), while no significant difference was observed between ASIR and FBP (P > 0.9 for ASIR vs. FBP for both readers). MBIR images were all diagnostically acceptable. Unique features of MBIR images included pixilated blotchy appearances, which did not adversely affect diagnostic acceptability. Conclusions: MBIR significantly improves image noise and streak artifacts of the cervicothoracic region over ASIR and FBP. MBIR is expected to enhance the value of CT examinations for areas where image noise and streak artifacts are problematic.

  1. Numerical simulation in applied geophysics

    CERN Document Server

    Santos, Juan Enrique

    2016-01-01

    This book presents the theory of waves propagation in a fluid-saturated porous medium (a Biot medium) and its application in Applied Geophysics. In particular, a derivation of absorbing boundary conditions in viscoelastic and poroelastic media is presented, which later is employed in the applications. The partial differential equations describing the propagation of waves in Biot media are solved using the Finite Element Method (FEM). Waves propagating in a Biot medium suffer attenuation and dispersion effects. In particular the fast compressional and shear waves are converted to slow diffusion-type waves at mesoscopic-scale heterogeneities (on the order of centimeters), effect usually occurring in the seismic range of frequencies. In some cases, a Biot medium presents a dense set of fractures oriented in preference directions. When the average distance between fractures is much smaller than the wavelengths of the travelling fast compressional and shear waves, the medium behaves as an effective viscoelastic an...

  2. Mammography with and without radiolucent positioning sheets : Comparison of projected breast area, pain experience, radiation dose and technical image quality

    NARCIS (Netherlands)

    Timmers, Janine; ten Voorde, Marloes; van Engen, Ruben E.; van Landsveld-Verhoeven, Cary; Pijnappel, Ruud; Droogh-de Greve, Kitty; den Heeten, Gerard J.; Broeders, Mireille J. M.

    2015-01-01

    Purpose: To compare projected breast area, image quality, pain experience and radiation dose between mammography performed with and without radiolucent positioning sheets. Methods: 184 women screened in the Dutch breast screening programme (May-June 2012) provided written informed consent to have

  3. Detection of sinkholes using 2D electrical resistivity imaging

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2002-07-01

    Full Text Available Sinkholes in dolomitic areas are notoriously difficult geophysical targets, and selecting an appropriate geophysical solution is not straightforward. Electrical resistivity imaging or tomography (RESTOM) is well suited to mapping sinkholes because...

  4. Geophysical drillhole logging and optical imaging of the drillholes OL-KR43, OL-KR44, OL-KR44B, OL-KR45, OL-KR45B, OL-KR46, OL-KR46B, OL-KR47, OL-KR47B and OL-KR48, at Olkiluoto 2007 and 2008

    International Nuclear Information System (INIS)

    Tarvainen, A.-M.; Heikkinen, E.

    2008-09-01

    Suomen Malmi Oy conducted geophysical drillhole logging and optical imaging of the drillholes OL-KR43, OL-KR44, OL-KR44B, OL-KR45, OL-KR45B, OL-KR46, OL-KR46B, OL-KR47, OL-KR47B and OL-KR48 at the Olkiluoto site in Eurajoki during December 2007, May 2008. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

  5. The Pilot Project 'Optical Image Correlation' of the ESA Geohazards Thematic Exploitation Platform (GTEP)

    Science.gov (United States)

    Stumpf, André; Malet, Jean-Philippe

    2016-04-01

    Since more than 20 years, "Earth Observation" (EO) satellites developed or operated by ESA have provided a wealth of data. In the coming years, the Sentinel missions, along with the Copernicus Contributing Missions as well as Earth Explorers and other, Third Party missions will provide routine monitoring of our environment at the global scale, thereby delivering an unprecedented amount of data. While the availability of the growing volume of environmental data from space represents a unique opportunity for science, general R&D, and applications, it also poses major challenges to fully exploit the potential of archived and daily incoming datasets. Those challenges do not only comprise the discovery, access, processing, and visualization of large data volumes but also an increasing diversity of data sources and end users from different fields (e.g. EO, in-situ monitoring, and modeling). In this context, the GTEP (Geohazards Thematic Exploitation Platform) initiative aims to build an operational distributed processing platform to maximize the exploitation of EO data from past and future satellite missions for the detection and monitoring of natural hazards. This presentation focuses on the "Optical Image Correlation" Pilot Project (funded by ESA within the GTEP platform) which objectives are to develop an easy-to-use, flexible and distributed processing chain for: 1) the automated reconstruction of surface Digital Elevation Models from stereo (and tristereo) pairs of Spot 6/7 and Pléiades satellite imagery, 2) the creation of ortho-images (panchromatic and multi-spectral) of Landsat 8, Sentinel-2, Spot 6/7 and Pléiades scenes, 3) the calculation of horizontal (E-N) displacement vectors based on sub-pixel image correlation. The processing chains is being implemented on the GEP cloud-based (Hadoop, MapReduce) environment and designed for analysis of surface displacements at local to regional scale (10-1000 km2) targeting in particular co-seismic displacement and slow

  6. Did Caravaggio employ optical projections? An image analysis of the parity in the artist's paintings

    Science.gov (United States)

    Stork, David G.

    2011-03-01

    We examine one class of evidence put forth in support of the recent claim that the Italian Baroque master Caravaggio secretly employed optical projectors as a direct drawing aid. Specically, we test the claims that there is an "abnormal number" of left-handed gures in his works and, more specically, that "During the Del Monte period he had too many left-handed models." We also test whether there was a reversal in the handedness of specic models in different paintings. Such evidence would be consistent with the claim that Caravaggio switched between using a convex-lens projector to using a concave-mirror projector and would support, but not prove, the claim that Caravaggio used optical projections. We estimate the parity (+ or -) of each of Caravaggio's 76 appropriate oil paintings based on the handedness of gures, the orientation of asymmetric objects, placement of scabbards, depicted text, and so on, and search for statistically significant changes in handedness in figures. We also track the direction of the illumination over time in the artist's uvre. We discuss some historical evidence as it relates to the question of his possible use of optics. We nd the proportion of left-handed figures lower than that in the general population (not higher), and no significant change in estimated handedness even of individual models. Optical proponents have argued that Bacchus (1597) portrays a left-handed gure, but we give visual and cultural evidence showing that this gure is instead right-handed, thereby rebutting this claim that the painting was executed using optical projections. Moreover, scholars recently re-discovered the image of the artist with easel and canvas reflected in the carafe of wine at the front left in the tableau in Bacchus, showing that this painting was almost surely executed using traditional (non-optical) easel methods. We conclude that there is 1) no statistically signicant abnormally high number of left-handed gures in Caravaggio's uvre, including

  7. Improving image quality in Electrical Impedance Tomography (EIT using Projection Error Propagation-based Regularization (PEPR technique: A simulation study

    Directory of Open Access Journals (Sweden)

    Tushar Kanti Bera

    2011-03-01

    Full Text Available A Projection Error Propagation-based Regularization (PEPR method is proposed and the reconstructed image quality is improved in Electrical Impedance Tomography (EIT. A projection error is produced due to the misfit of the calculated and measured data in the reconstruction process. The variation of the projection error is integrated with response matrix in each iterations and the reconstruction is carried out in EIDORS. The PEPR method is studied with the simulated boundary data for different inhomogeneity geometries. Simulated results demonstrate that the PEPR technique improves image reconstruction precision in EIDORS and hence it can be successfully implemented to increase the reconstruction accuracy in EIT.>doi:10.5617/jeb.158 J Electr Bioimp, vol. 2, pp. 2-12, 2011

  8. Sliding thin slab, minimum intensity projection imaging for objective analysis of emphysema

    International Nuclear Information System (INIS)

    Satoh, Shiro; Ohdama, Shinichi; Shibuya, Hitoshi

    2006-01-01

    The aim of this study was to determine whether sliding thin slab, minimum intensity projection (STS-MinIP) imaging is more advantageous than thin-section computed tomography (CT) for detecting and assessing emphysema. Objective quantification of emphysema by STS-MinIP and thin-section CT was defined as the percentage of area lower than the threshold in the lung section at the level of the aortic arch, tracheal carina, and 5 cm below the carina. Quantitative analysis in 100 subjects was performed and compared with pulmonary function test results. The ratio of the low attenuation area in the lung measured by STS-MinIP was significantly higher than that found by thin-section CT (P<0.01). The difference between STS-MinIP and thin-section CT was statistically evident even for mild emphysema and increased depending on whether the low attenuation in the lung increased. Moreover, STS-MinIP showed a stronger regression relation with pulmonary function results than did thin-section CT (P<0.01). STS-MinIP can be recommended as a new morphometric method for detecting and assessing the severity of emphysema. (author)

  9. Envision: An interactive system for the management and visualization of large geophysical data sets

    Science.gov (United States)

    Searight, K. R.; Wojtowicz, D. P.; Walsh, J. E.; Pathi, S.; Bowman, K. P.; Wilhelmson, R. B.

    1995-01-01

    Envision is a software project at the University of Illinois and Texas A&M, funded by NASA's Applied Information Systems Research Project. It provides researchers in the geophysical sciences convenient ways to manage, browse, and visualize large observed or model data sets. Envision integrates data management, analysis, and visualization of geophysical data in an interactive environment. It employs commonly used standards in data formats, operating systems, networking, and graphics. It also attempts, wherever possible, to integrate with existing scientific visualization and analysis software. Envision has an easy-to-use graphical interface, distributed process components, and an extensible design. It is a public domain package, freely available to the scientific community.

  10. The Yosemite Extreme Panoramic Imaging Project: Monitoring Rockfall in Yosemite Valley with High-Resolution, Three-Dimensional Imagery

    Science.gov (United States)

    Stock, G. M.; Hansen, E.; Downing, G.

    2008-12-01

    Yosemite Valley experiences numerous rockfalls each year, with over 600 rockfall events documented since 1850. However, monitoring rockfall activity has proved challenging without high-resolution "basemap" imagery of the Valley walls. The Yosemite Extreme Panoramic Imaging Project, a partnership between the National Park Service and xRez Studio, has created an unprecedented image of Yosemite Valley's walls by utilizing gigapixel panoramic photography, LiDAR-based digital terrain modeling, and three-dimensional computer rendering. Photographic capture was accomplished by 20 separate teams shooting from key overlapping locations throughout Yosemite Valley. The shots were taken simultaneously in order to ensure uniform lighting, with each team taking over 500 overlapping shots from each vantage point. Each team's shots were then assembled into 20 gigapixel panoramas. In addition, all 20 gigapixel panoramas were projected onto a 1 meter resolution digital terrain model in three-dimensional rendering software, unifying Yosemite Valley's walls into a vertical orthographic view. The resulting image reveals the geologic complexity of Yosemite Valley in high resolution and represents one of the world's largest photographic captures of a single area. Several rockfalls have already occurred since image capture, and repeat photography of these areas clearly delineates rockfall source areas and failure dynamics. Thus, the imagery has already proven to be a valuable tool for monitoring and understanding rockfall in Yosemite Valley. It also sets a new benchmark for the quality of information a photographic image, enabled with powerful new imaging technology, can provide for the earth sciences.

  11. Geophysical study of the Peinan Archaeological Site, Taiwan

    Science.gov (United States)

    Tong, Lun-Tao; Lee, Kun-Hsiu; Yeh, Chang-Keng; Hwang, Yan-Tsong; Chien, Jeng-Ming

    2013-02-01

    The Peinan archaeological site is the most intact Neolithic village with slate coffin burial complexes in Taiwan. However, the area that potentially contains significant ancient remains is covered by dense vegetation. No reliable data show the distribution of the ancient village, and no geophysical investigation has been performed at this site. To evaluate various geophysical methods under the geological setting and surface condition of the site, the physical properties of the remains were measured and four geophysical methods involving magnetic, electromagnetic (EM), electrical resistivity tomography (ERT), and ground-penetrating radar (GPR) were tested along three parallel profiles. The results imply that the EM and magnetic methods are much cost-effective and suitable for investigating the entire area. GPR and ERT methods can provide high resolution subsurface image, which are much suitable for subsequently detail investigation. The EM and magnetic surveys were thus conducted over the entire Peinan Cultural Park to understand the distribution of the ancient building remains at the Peinan site. The results of this study were verified by subsequent excavations, which indicate that the EM survey was successful in delineating the majority of the ancient village because the basements of building are highly resistive in comparison to the background sediment. The results of this investigation suggest that the ancient village was broadly distributed over the eastern part of the Peinan Culture Park and extended to the southeast.

  12. Integrated geophysical investigations of Main Barton Springs, Austin, Texas, USA

    Science.gov (United States)

    Saribudak, By Mustafa; Hauwert, Nico M.

    2017-03-01

    Barton Springs is a major discharge site for the Barton Springs Segment of the Edwards Aquifer and is located in Zilker Park, Austin, Texas. Barton Springs actually consists of at least four springs. The Main Barton Springs discharges into the Barton Springs pool from the Barton Springs fault and several outlets along a fault, from a cave, several fissures, and gravel-filled solution cavities on the floor of the pool west of the fault. Surface geophysical surveys [resistivity imaging, induced polarization (IP), self-potential (SP), seismic refraction, and ground penetrating radar (GPR)] were performed across the Barton Springs fault and at the vicinity of the Main Barton Springs in south Zilker Park. The purpose of the surveys was two-fold: 1) locate the precise location of submerged conduits (caves, voids) carrying flow to Main Barton Springs; and 2) characterize the geophysical signatures of the fault crossing Barton Springs pool. Geophysical results indicate significant anomalies to the south of the Barton Springs pool. A majority of these anomalies indicate a fault-like pattern, in front of the south entrance to the swimming pool. In addition, resistivity and SP results, in particular, suggest the presence of a large conduit in the southern part of Barton Springs pool. The groundwater flow-path to the Main Barton Springs could follow the locations of those resistivity and SP anomalies along the newly discovered fault, instead of along the Barton Springs fault, as previously thought.

  13. Space Geodesy Monitoring Mass Transport in Global Geophysical Fluids

    Science.gov (United States)

    Chao, Benjamin F.

    2004-01-01

    Mass transports occurring in the atmosphere-hydrosphere-cryosphere-solid Earth-core system (the 'global geophysical fluids') are important geophysical phenomena. They occur on all temporal and spatial scales. Examples include air mass and ocean circulations, oceanic and solid tides, hydrological water and idsnow redistribution, mantle processes such as post-glacial rebound, earthquakes and tectonic motions, and core geodynamo activities. The temporal history and spatial pattern of such mass transport are often not amenable to direct observations. Space geodesy techniques, however, have proven to be an effective tool in monitorihg certain direct consequences of the mass transport, including Earth's rotation variations, gravitational field variations, and the geocenter motion. Considerable advances have been made in recent years in observing and understanding of these geodynamic effects. This paper will use several prominent examples to illustrate the triumphs in research over the past years under a 'Moore's law' in space geodesy. New space missions and projects promise to further advance our knowledge about the global mass transports. The latter contributes to our understanding of the geophysical processes that produce and regulate the mass transports, as well as of the solid Earth's response to such changes in terms of Earth's mechanical properties.

  14. Multi-detector and systematic imaging system designed and developed within the New AGLAE project

    Energy Technology Data Exchange (ETDEWEB)

    Pichon, L.; Pacheco, C.; Moignard, B.; Lemasson, Q. [C2RMF - Palais du Louvre 14 quai F Mitterrand 75001, Paris (France); FR3605 - MCC/CNRS/UPMC (France); Guillou, T.; Walter, Ph [FR3605 - CC/CNRS/UPMC (France); LAMS - UMR 8220 - CNRS/UPMC - Seine, Paris (France)

    2013-07-01

    Full text: The New AGLAE project aims to establish a world-class facility for non invasive analysis of Cultural Heritage materials. One of the objectives of the New AGLAE project is to increase the x-ray measurement detection, enabling to reduce the beam intensity thus the interaction with sensitive artworks by a ten. Multidisciplinary, the New AGLAE project will provide an exceptional and multipurpose beam line with a performance in spatial resolution, beam stability and a capability of multi-particle detection much higher than for the previous facility. The New AGLAE will give fundamental elements for the understanding of the structure of materials, their composition, properties, and change over time. One of the objectives of this project is to design and set up a new data acquisition system. To reach that purpose, the surface and the number of PIXE detectors have been increased. Indeed, a 10 mm{sup 2} and a 30 mm{sup 3} Si(Li) detectors respectively dedicated to low and high energy measurements, were replaced by a cluster of five 50 mm{sup 2} S.D.D. detectors. If this multi detector enables to decrease the intensity of the incident beam by one order of magnitude, involving less irradiation during the analysis, it can also provide large and/or fast maps. So as to digital the preamp pulses obtained from the detectors, a custom Digital X-ray Processor provides both digital data and control signals compatible to a multiparameter multichannel system. This multiparameter system saves each event from x-ray, gamma and particle detectors and simultaneously the X, Y positions of the beam on the sample as a list file. Furthermore, to draw several-cm-sized maps with a 20/40μm resolution, the scanning of the area originally combines a fast vertical magnetic deflection of the beam and a mechanical movement of the target. To process the data, several homemade software have been developed or updated so as to rebuild any matrix of spectra, to re-bin maps, to process a series of

  15. Calibration and Confirmation in Geophysical Models

    Science.gov (United States)

    Werndl, Charlotte

    2016-04-01

    For policy decisions the best geophysical models are needed. To evaluate geophysical models, it is essential that the best available methods for confirmation are used. A hotly debated issue on confirmation in climate science (as well as in philosophy) is the requirement of use-novelty (i.e. that data can only confirm models if they have not already been used before. This talk investigates the issue of use-novelty and double-counting for geophysical models. We will see that the conclusions depend on the framework of confirmation and that it is not clear that use-novelty is a valid requirement and that double-counting is illegitimate.

  16. Image quality and dose in mammography in 17 countries in Africa, Asia and Eastern Europe: Results from IAEA projects

    International Nuclear Information System (INIS)

    Ciraj-Bjelac, Olivera; Avramova-Cholakova, Simona; Beganovic, Adnan; Economides, Sotirios; Faj, Dario; Gershan, Vesna; Grupetta, Edward; Kharita, M.H.; Milakovic, Milomir; Milu, Constantin; Muhogora, Wilbroad E.; Muthuvelu, Pirunthavany; Oola, Samuel; Setayeshi, Saeid

    2012-01-01

    Purpose: The objective is to study mammography practice from an optimisation point of view by assessing the impact of simple and immediately implementable corrective actions on image quality. Materials and methods: This prospective multinational study included 54 mammography units in 17 countries. More than 21,000 mammography images were evaluated using a three-level image quality scoring system. Following initial assessment, appropriate corrective actions were implemented and image quality was re-assessed in 24 units. Results: The fraction of images that were considered acceptable without any remark in the first phase (before the implementation of corrective actions) was 70% and 75% for cranio-caudal and medio-lateral oblique projections, respectively. The main causes for poor image quality before corrective actions were related to film processing, damaged or scratched image receptors, or film-screen combinations that are not spectrally matched, inappropriate radiographic techniques and lack of training. Average glandular dose to a standard breast was 1.5 mGy (mean and range 0.59–3.2 mGy). After optimisation the frequency of poor quality images decreased, but the relative contributions of the various causes remained similar. Image quality improvements following appropriate corrective actions were up to 50 percentage points in some facilities. Conclusions: Poor image quality is a major source of unnecessary radiation dose to the breast. An increased awareness of good quality mammograms is of particular importance for countries that are moving towards introduction of population-based screening programmes. The study demonstrated how simple and low-cost measures can be a valuable tool in improving of image quality in mammography

  17. Geophysical Anomalies and Earthquake Prediction

    Science.gov (United States)

    Jackson, D. D.

    2008-12-01

    Finding anomalies is easy. Predicting earthquakes convincingly from such anomalies is far from easy. Why? Why have so many beautiful geophysical abnormalities not led to successful prediction strategies? What is earthquake prediction? By my definition it is convincing information that an earthquake of specified size is temporarily much more likely than usual in a specific region for a specified time interval. We know a lot about normal earthquake behavior, including locations where earthquake rates are higher than elsewhere, with estimable rates and size distributions. We know that earthquakes have power law size distributions over large areas, that they cluster in time and space, and that aftershocks follow with power-law dependence on time. These relationships justify prudent protective measures and scientific investigation. Earthquake prediction would justify exceptional temporary measures well beyond those normal prudent actions. Convincing earthquake prediction would result from methods that have demonstrated many successes with few false alarms. Predicting earthquakes convincingly is difficult for several profound reasons. First, earthquakes start in tiny volumes at inaccessible depth. The power law size dependence means that tiny unobservable ones are frequent almost everywhere and occasionally grow to larger size. Thus prediction of important earthquakes is not about nucleation, but about identifying the conditions for growth. Second, earthquakes are complex. They derive their energy from stress, which is perniciously hard to estimate or model because it is nearly singular at the margins of cracks and faults. Physical properties vary from place to place, so the preparatory processes certainly vary as well. Thus establishing the needed track record for validation is very difficult, especially for large events with immense interval times in any one location. Third, the anomalies are generally complex as well. Electromagnetic anomalies in particular require

  18. Nonintrusive iris image acquisition system based on a pan-tilt-zoom camera and light stripe projection

    Science.gov (United States)

    Yoon, Soweon; Jung, Ho Gi; Park, Kang Ryoung; Kim, Jaihie

    2009-03-01

    Although iris recognition is one of the most accurate biometric technologies, it has not yet been widely used in practical applications. This is mainly due to user inconvenience during the image acquisition phase. Specifically, users try to adjust their eye position within small capture volume at a close distance from the system. To overcome these problems, we propose a novel iris image acquisition system that provides users with unconstrained environments: a large operating range, enabling movement from standing posture, and capturing good-quality iris images in an acceptable time. The proposed system has the following three contributions compared with previous works: (1) the capture volume is significantly increased by using a pan-tilt-zoom (PTZ) camera guided by a light stripe projection, (2) the iris location in the large capture volume is found fast due to 1-D vertical face searching from the user's horizontal position obtained by the light stripe projection, and (3) zooming and focusing on the user's irises at a distance are accurate and fast using the estimated 3-D position of a face by the light stripe projection and the PTZ camera. Experimental results show that the proposed system can capture good-quality iris images in 2.479 s on average at a distance of 1.5 to 3 m, while allowing a limited amount of movement by the user.

  19. SU-C-209-05: Monte Carlo Model of a Prototype Backscatter X-Ray (BSX) Imager for Projective and Selective Object-Plane Imaging

    International Nuclear Information System (INIS)

    Rolison, L; Samant, S; Baciak, J; Jordan, K

    2016-01-01

    Purpose: To develop a Monte Carlo N-Particle (MCNP) model for the validation of a prototype backscatter x-ray (BSX) imager, and optimization of BSX technology for medical applications, including selective object-plane imaging. Methods: BSX is an emerging technology that represents an alternative to conventional computed tomography (CT) and projective digital radiography (DR). It employs detectors located on the same side as the incident x-ray source, making use of backscatter and avoiding ring geometry to enclose the imaging object. Current BSX imagers suffer from low spatial resolution. A MCNP model was designed to replicate a BSX prototype used for flaw detection in industrial materials. This prototype consisted of a 1.5mm diameter 60kVp pencil beam surrounded by a ring of four 5.0cm diameter NaI scintillation detectors. The imaging phantom consisted of a 2.9cm thick aluminum plate with five 0.6cm diameter holes drilled halfway. The experimental image was created using a raster scanning motion (in 1.5mm increments). Results: A qualitative comparison between the physical and simulated images showed very good agreement with 1.5mm spatial resolution in plane perpendicular to incident x-ray beam. The MCNP model developed the concept of radiography by selective plane detection (RSPD) for BSX, whereby specific object planes can be imaged by varying kVp. 10keV increments in mean x-ray energy yielded 4mm thick slice resolution in the phantom. Image resolution in the MCNP model can be further increased by increasing the number of detectors, and decreasing raster step size. Conclusion: MCNP modelling was used to validate a prototype BSX imager and introduce the RSPD concept, allowing for selective object-plane imaging. There was very good visual agreement between the experimental and MCNP imaging. Beyond optimizing system parameters for the existing prototype, new geometries can be investigated for volumetric image acquisition in medical applications. This material is

  20. SU-C-209-05: Monte Carlo Model of a Prototype Backscatter X-Ray (BSX) Imager for Projective and Selective Object-Plane Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Rolison, L; Samant, S; Baciak, J; Jordan, K [University of Florida, Gainesville, FL (United States)

    2016-06-15

    Purpose: To develop a Monte Carlo N-Particle (MCNP) model for the validation of a prototype backscatter x-ray (BSX) imager, and optimization of BSX technology for medical applications, including selective object-plane imaging. Methods: BSX is an emerging technology that represents an alternative to conventional computed tomography (CT) and projective digital radiography (DR). It employs detectors located on the same side as the incident x-ray source, making use of backscatter and avoiding ring geometry to enclose the imaging object. Current BSX imagers suffer from low spatial resolution. A MCNP model was designed to replicate a BSX prototype used for flaw detection in industrial materials. This prototype consisted of a 1.5mm diameter 60kVp pencil beam surrounded by a ring of four 5.0cm diameter NaI scintillation detectors. The imaging phantom consisted of a 2.9cm thick aluminum plate with five 0.6cm diameter holes drilled halfway. The experimental image was created using a raster scanning motion (in 1.5mm increments). Results: A qualitative comparison between the physical and simulated images showed very good agreement with 1.5mm spatial resolution in plane perpendicular to incident x-ray beam. The MCNP model developed the concept of radiography by selective plane detection (RSPD) for BSX, whereby specific object planes can be imaged by varying kVp. 10keV increments in mean x-ray energy yielded 4mm thick slice resolution in the phantom. Image resolution in the MCNP model can be further increased by increasing the number of detectors, and decreasing raster step size. Conclusion: MCNP modelling was used to validate a prototype BSX imager and introduce the RSPD concept, allowing for selective object-plane imaging. There was very good visual agreement between the experimental and MCNP imaging. Beyond optimizing system parameters for the existing prototype, new geometries can be investigated for volumetric image acquisition in medical applications. This material is

  1. Geophysical Methods for Non-Destructive Testing in Civil Engineering

    Science.gov (United States)

    Niederleithinger, E.

    2013-12-01

    Many non-destructive testing (NDT) methods for civil engineering (e. g. ultrasonics, radar) are similar to geophysical techniques. They just differ in scale, material under investigation and vocabulary used. In spite of the fact that the same principles of physics and mathematics apply to both fields, exchange has been limited in the past. But since a few years more and more geophysical knowledge is used in civil engineering. One of the focal points in research is to improve ultrasonic testing of concrete to be able to image the inside even of large, complex structures and to detect any deterioration as early as possible. One of the main issues is the heterogeneity of concrete, including aggregates, reinforcement, cracks and many other features. Our current research focuses on three points. One is the application of state of the art geophysical migration techniques as Reverse Time Migration (RTM) to image vertical faces or the backside of voids and ducts in thick concrete structures, which isn't possible with conventional techniques used in NDT. Second, we have started to use seismic interferometric techniques to interpolate ultrasonic traces, which can't be measured directly for technical reasons. Third, we are using coda wave interferometry to detect concrete degradation due to load, fatigue, temperature or other influences as early as possible. Practical examples of the application of these techniques are given and potential future research directions will be discussed. It will be shown, how a subset of these techniques can be used for innovative monitoring systems for civil infrastructure. Imaging the interior of a concrete body by ultrasonics and reverse time migration(simulated data).

  2. Diagnosing and mapping pulmonary emphysema on X-ray projection images: incremental value of grating-based X-ray dark-field imaging.

    Science.gov (United States)

    Meinel, Felix G; Schwab, Felix; Schleede, Simone; Bech, Martin; Herzen, Julia; Achterhold, Klaus; Auweter, Sigrid; Bamberg, Fabian; Yildirim, Ali Ö; Bohla, Alexander; Eickelberg, Oliver; Loewen, Rod; Gifford, Martin; Ruth, Ronald; Reiser, Maximilian F; Pfeiffer, Franz; Nikolaou, Konstantin

    2013-01-01

    To assess whether grating-based X-ray dark-field imaging can increase the sensitivity of X-ray projection images in the diagnosis of pulmonary emphysema and allow for a more accurate assessment of emphysema distribution. Lungs from three mice with pulmonary emphysema and three healthy mice were imaged ex vivo using a laser-driven compact synchrotron X-ray source. Median signal intensities of transmission (T), dark-field (V) and a combined parameter (normalized scatter) were compared between emphysema and control group. To determine the diagnostic value of each parameter in differentiating between healthy and emphysematous lung tissue, a receiver-operating-characteristic (ROC) curve analysis was performed both on a per-pixel and a per-individual basis. Parametric maps of emphysema distribution were generated using transmission, dark-field and normalized scatter signal and correlated with histopathology. Transmission values relative to water were higher for emphysematous lungs than for control lungs (1.11 vs. 1.06, pemphysema provides color-coded parametric maps, which show the best correlation with histopathology. In a murine model, the complementary information provided by X-ray transmission and dark-field images adds incremental diagnostic value in detecting pulmonary emphysema and visualizing its regional distribution as compared to conventional X-ray projections.

  3. PLÉIADES PROJECT: ASSESSMENT OF GEOREFERENCING ACCURACY, IMAGE QUALITY, PANSHARPENING PERFORMENCE AND DSM/DTM QUALITY

    Directory of Open Access Journals (Sweden)

    H. Topan

    2016-06-01

    Full Text Available Pléiades 1A and 1B are twin optical satellites of Optical and Radar Federated Earth Observation (ORFEO program jointly running by France and Italy. They are the first satellites of Europe with sub-meter resolution. Airbus DS (formerly Astrium Geo runs a MyGIC (formerly Pléiades Users Group program to validate Pléiades images worldwide for various application purposes. The authors conduct three projects, one is within this program, the second is supported by BEU Scientific Research Project Program, and the third is supported by TÜBİTAK. Assessment of georeferencing accuracy, image quality, pansharpening performance and Digital Surface Model/Digital Terrain Model (DSM/DTM quality subjects are investigated in these projects. For these purposes, triplet panchromatic (50 cm Ground Sampling Distance (GSD and VNIR (2 m GSD Pléiades 1A images were investigated over Zonguldak test site (Turkey which is urbanised, mountainous and covered by dense forest. The georeferencing accuracy was estimated with a standard deviation in X and Y (SX, SY in the range of 0.45m by bias corrected Rational Polynomial Coefficient (RPC orientation, using ~170 Ground Control Points (GCPs. 3D standard deviation of ±0.44m in X, ±0.51m in Y, and ±1.82m in Z directions have been reached in spite of the very narrow angle of convergence by bias corrected RPC orientation. The image quality was also investigated with respect to effective resolution, Signal to Noise Ratio (SNR and blur coefficient. The effective resolution was estimated with factor slightly below 1.0, meaning that the image quality corresponds to the nominal resolution of 50cm. The blur coefficients were achieved between 0.39-0.46 for triplet panchromatic images, indicating a satisfying image quality. SNR is in the range of other comparable space borne images which may be caused by de-noising of Pléiades images. The pansharpened images were generated by various methods, and are validated by most common

  4. Imaging reconstruction based on improved wavelet denoising combined with parallel-beam filtered back-projection algorithm

    Science.gov (United States)

    Ren, Zhong; Liu, Guodong; Huang, Zhen

    2012-11-01

    The image reconstruction is a key step in medical imaging (MI) and its algorithm's performance determinates the quality and resolution of reconstructed image. Although some algorithms have been used, filter back-projection (FBP) algorithm is still the classical and commonly-used algorithm in clinical MI. In FBP algorithm, filtering of original projection data is a key step in order to overcome artifact of the reconstructed image. Since simple using of classical filters, such as Shepp-Logan (SL), Ram-Lak (RL) filter have some drawbacks and limitations in practice, especially for the projection data polluted by non-stationary random noises. So, an improved wavelet denoising combined with parallel-beam FBP algorithm is used to enhance the quality of reconstructed image in this paper. In the experiments, the reconstructed effects were compared between the improved wavelet denoising and others (directly FBP, mean filter combined FBP and median filter combined FBP method). To determine the optimum reconstruction effect, different algorithms, and different wavelet bases combined with three filters were respectively test. Experimental results show the reconstruction effect of improved FBP algorithm is better than that of others. Comparing the results of different algorithms based on two evaluation standards i.e. mean-square error (MSE), peak-to-peak signal-noise ratio (PSNR), it was found that the reconstructed effects of the improved FBP based on db2 and Hanning filter at decomposition scale 2 was best, its MSE value was less and the PSNR value was higher than others. Therefore, this improved FBP algorithm has potential value in the medical imaging.

  5. INEL cold test pit demonstration of improvements in information derived from non-intrusive geophysical methods over buried waste sites

    International Nuclear Information System (INIS)

    1993-01-01

    The objectives of this research project were to lay the foundation for further improvement in the use of geophysical methods for detection of buried wastes, and to increase the information content derived from surveys. Also, an important goal was to move from mere detection to characterization of buried wastes. The technical approach to achieve these objectives consisted of: (1) Collect a data set of high spatial density; (2) Acquire data with multiple sensors and integrate the interpretations inferred from the various sensors; (3) Test a simplified time domain electromagnetic system; and (4) Develop imaging and display formats of geophysical data readily understood by environmental scientists and engineers. The breadth of application of this work is far reaching. Not only are uncontrolled waste pits and trenches, abandoned underground storage tanks, and pipelines found throughout most US DOE facilities, but also at military installations and industrial facilities. Moreover, controlled land disposal sites may contain ''hot spots'' where drums and hazardous material may have been buried. The technologies addressed by the R ampersand D will benefit all of these activities

  6. Comparing plume characteristics inferred from cross-borehole geophysical data

    DEFF Research Database (Denmark)

    Haarder, Eline Bojsen; Binley, Andrew; Zibar, Majken Caroline Looms

    2012-01-01

    significantly influences results of the moment analysis. We compare results of three cross-borehole geophysical approaches for imaging tracer migration arising from a point injection of water in the unsaturated zone: three-dimensional electrical resistivity tomography (ERT), two-dimensional ground......-penetrating radar (GPR) tomography and quasi-three-dimensional GPR tomography. In the studied field experiment, a tracer was injected for a period of 5 d and was monitored both during injection and for 5 d during the subsequent redistribution. The three methods show similar characteristics of the plume development...

  7. Evaluation of ground stiffness parameters using continuous surface wave geophysics

    DEFF Research Database (Denmark)

    Gordon, Anne; Foged, Niels

    2000-01-01

    Present day knowledge of the magnitude of the strain levels in the ground associated with geotechnical structures, together with an increasing number of projects requiring the best estimates of ground movements around excavations, has led to, inter alia, increased interest in measuring the very......-small-strain stiffness of the ground Gmax. Continuous surface wave geophysics offers a quick, non-intrusive and economical way of making such measurements. This paper reviews the continuous surface wave techniques and evaluates, in engineering terms, the applicability of the method to the site investigation industry....

  8. Fundamentals of Geophysical Fluid Dynamics

    Science.gov (United States)

    McWilliams, James C.

    2006-07-01

    Earth's atmosphere and oceans exhibit complex patterns of fluid motion over a vast range of space and time scales. These patterns combine to establish the climate in response to solar radiation that is inhomogeneously absorbed by the materials comprising air, water, and land. Spontaneous, energetic variability arises from instabilities in the planetary-scale circulations, appearing in many different forms such as waves, jets, vortices, boundary layers, and turbulence. Geophysical fluid dynamics (GFD) is the science of all these types of fluid motion. This textbook is a concise and accessible introduction to GFD for intermediate to advanced students of the physics, chemistry, and/or biology of Earth's fluid environment. The book was developed from the author's many years of teaching a first-year graduate course at the University of California, Los Angeles. Readers are expected to be familiar with physics and mathematics at the level of general dynamics (mechanics) and partial differential equations. Covers the essential GFD required for atmospheric science and oceanography courses Mathematically rigorous, concise coverage of basic theory and applications to both oceans and atmospheres Author is a world expert; this book is based on the course he has taught for many years Exercises are included, with solutions available to instructors from solutions@cambridge.org

  9. Airborne geophysical radon hazard mapping

    International Nuclear Information System (INIS)

    Walker, P.

    1993-01-01

    Shales containing uranium pose a radon health hazard even when covered by several meters of overburden. Such an alum shale in southern Norway has been mapped with a joint helicopter borne electromagnetic (HEM) and radiometric survey. Results are compared with ground spectrometer, radon emanometer and radon gas measurements in dwellings, and a model to predict radon gas concentrations from the airborne data is developed. Since the shale is conductive, combining the HEM data with the radiometric channel allows the shale to be mapped with greater reliability than if the radiometric channel were used alone. Radiometrically more active areas which do not pose a radon gas hazard can thus be separated from the shales which do. The ground follow-up work consisted of spectrometer and radon emanometer measurements over a uranium anomaly coinciding with a conductor. The correlation between the airborne uranium channel, the ground uranium channel and emanometry is extremely good, indicating that airborne geophysics can, in this case, be used to predict areas having a high radon potential. Contingency tables comparing both radon exhalation and concentration in dwellings with the airborne uranium data show a strong relationship exists between exhalation and the airborne data and while a relationship between concentration and the airborne data is present, but weaker

  10. Tabletop Models for Electrical and Electromagnetic Geophysics.

    Science.gov (United States)

    Young, Charles T.

    2002-01-01

    Details the use of tabletop models that demonstrate concepts in direct current electrical resistivity, self-potential, and electromagnetic geophysical models. Explains how data profiles of the models are obtained. (DDR)

  11. rights reserved Geophysical Identification of Hydrothermally Altered

    African Journals Online (AJOL)

    ADOWIE PERE

    Geophysical Identification of Hydrothermally Altered Structures That Favour .... aircraft. Total line kilometers of 36,500 were covered in the survey. Magnetic ... tie lines occur at about 2000 metres interval in the ... visual inspection of the map.

  12. Exploring the oceans- The geophysical way

    Digital Repository Service at National Institute of Oceanography (India)

    Murthy, K.S.R.

    The evolution of the eastern continental margin of India (ECMI), the Bengal Fan and the Central Indian Basin (CIB) is a consequence of the breakup of India from the eastern Gondwanaland in Late Jurassic to Early Cretaceous. Recent marine geophysical...

  13. A geological and geophysical data collection system

    Digital Repository Service at National Institute of Oceanography (India)

    Sudhakar, T.; Afzulpurkar, S.

    A geological and geophysical data collection system using a Personal Computer is described below. The system stores data obtained from various survey systems typically installed in a charter vessel and can be used for similar applications on any...

  14. Image and diagnosis quality of X-ray image transmission via cell phone camera: a project study evaluating quality and reliability.

    Directory of Open Access Journals (Sweden)

    Hans Goost

    Full Text Available INTRODUCTION: Developments in telemedicine have not produced any relevant benefits for orthopedics and trauma surgery to date. For the present project study, several parameters were examined during assessment of x-ray images, which had been photographed and transmitted via cell phone. MATERIALS AND METHODS: A total of 100 x-ray images of various body regions were photographed with a Nokia cell phone and transmitted via email or MMS. Next, the transmitted photographs were reviewed on a laptop computer by five medical specialists and assessed regarding quality and diagnosis. RESULTS: Due to their poor quality, the transmitted MMS images could not be evaluated and this path of transmission was therefore excluded. Mean size of transmitted x-ray email images was 394 kB (range: 265-590 kB, SD ± 59, average transmission time was 3.29 min ± 8 (CI 95%: 1.7-4.9. Applying a score from 1-10 (very poor - excellent, mean image quality was 5.8. In 83.2 ± 4% (mean value ± SD of cases (median 82; 80-89%, there was agreement between final diagnosis and assessment by the five medical experts who had received the images. However, there was a markedly low concurrence ratio in the thoracic area and in pediatric injuries. DISCUSSION: While the rate of accurate diagnosis and indication for surgery was high with a concurrence ratio of 83%, considerable differences existed between the assessed regions, with lowest values for thoracic images. Teleradiology is a cost-effective, rapid method which can be applied wherever wireless cell phone reception is available. In our opinion, this method is in principle suitable for clinical use, enabling the physician on duty to agree on appropriate measures with colleagues located elsewhere via x-ray image transmission on a cell phone.

  15. Fundamental remote science research program. Part 2: Status report of the mathematical pattern recognition and image analysis project

    Science.gov (United States)

    Heydorn, R. P.

    1984-01-01

    The Mathematical Pattern Recognition and Image Analysis (MPRIA) Project is concerned with basic research problems related to the study of he Earth from remotely sensed measurements of its surface characteristics. The program goal is to better understand how to analyze the digital image that represents the spatial, spectral, and temporal arrangement of these measurements for purposing of making selected inferences about the Earth. This report summarizes the progress that has been made toward this program goal by each of the principal investigators in the MPRIA Program.

  16. Geophysical investigations in the Kivetty area, Finland

    International Nuclear Information System (INIS)

    Heikkinen, E.; Paananen, M.; Oehberg, A.; Front, K.; Okko, O.; Pitkaenen, P.

    1992-09-01

    Investigations were carried out at Kivetty site in Konginkangas, in central Finland, by geological, geophysical, geohydrological and geochemical methods in 1987-1991 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. Airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

  17. Geophysical investigations in the Syyry area, Finland

    International Nuclear Information System (INIS)

    Heikkinen, E.; Kurimo, M.

    1992-12-01

    Investigations were carried out at the Syyry site at Sievi using geological, geophysical, geohydrological and geochemical methods in 1987-1991 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. In this survey airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

  18. Geophysical investigations in the Olkiluoto area, Finland

    International Nuclear Information System (INIS)

    Heikkinen, E.; Paananen, M.

    1992-12-01

    Investigations were carried out at the Olkiluoto site at Eurajoki using geological, geophysical, geohydrological and geochemical methods in 1987-1992 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. In this survey airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

  19. uranium and thorium exploration by geophysical methods

    International Nuclear Information System (INIS)

    Yueksel, F.A.; Kanli, A.I.

    1997-01-01

    Radioactivity is often measured from the ground in mineral exploration. If large areas have to be investigated, it is often unsuitable to carry out the measurements with ground-bound expeditions. A geophysical method of gamma-ray spectrometry is generally applied for uranium exploration. Exploration of uranium surveys were stopped after the year of 1990 in Turkey. Therefore the real potential of uranium in Turkey have to be investigated by using the geophysical techniques

  20. Digital tomosynthesis parallel imaging computational analysis with shift and add and back projection reconstruction algorithms.

    Science.gov (United States)

    Chen, Ying; Balla, Apuroop; Rayford II, Cleveland E; Zhou, Weihua; Fang, Jian; Cong, Linlin

    2010-01-01

    Digital tomosynthesis is a novel technology that has been developed for various clinical applications. Parallel imaging configuration is utilised in a few tomosynthesis imaging areas such as digital chest tomosynthesis. Recently, parallel imaging configuration for breast tomosynthesis began to appear too. In this paper, we present the investigation on computational analysis of impulse response characterisation as the start point of our important research efforts to optimise the parallel imaging configurations. Results suggest that impulse response computational analysis is an effective method to compare and optimise imaging configurations.

  1. Fast, accurate, and robust automatic marker detection for motion correction based on oblique kV or MV projection image pairs

    International Nuclear Information System (INIS)

    Slagmolen, Pieter; Hermans, Jeroen; Maes, Frederik; Budiharto, Tom; Haustermans, Karin; Heuvel, Frank van den

    2010-01-01

    Purpose: A robust and accurate method that allows the automatic detection of fiducial markers in MV and kV projection image pairs is proposed. The method allows to automatically correct for inter or intrafraction motion. Methods: Intratreatment MV projection images are acquired during each of five treatment beams of prostate cancer patients with four implanted fiducial markers. The projection images are first preprocessed using a series of marker enhancing filters. 2D candidate marker locations are generated for each of the filtered projection images and 3D candidate marker locations are reconstructed by pairing candidates in subsequent projection images. The correct marker positions are retrieved in 3D by the minimization of a cost function that combines 2D image intensity and 3D geometric or shape information for the entire marker configuration simultaneously. This optimization problem is solved using dynamic programming such that the globally optimal configuration for all markers is always found. Translational interfraction and intrafraction prostate motion and the required patient repositioning is assessed from the position of the centroid of the detected markers in different MV image pairs. The method was validated on a phantom using CT as ground-truth and on clinical data sets of 16 patients using manual marker annotations as ground-truth. Results: The entire setup was confirmed to be accurate to around 1 mm by the phantom measurements. The reproducibility of the manual marker selection was less than 3.5 pixels in the MV images. In patient images, markers were correctly identified in at least 99% of the cases for anterior projection images and 96% of the cases for oblique projection images. The average marker detection accuracy was 1.4±1.8 pixels in the projection images. The centroid of all four reconstructed marker positions in 3D was positioned within 2 mm of the ground-truth position in 99.73% of all cases. Detecting four markers in a pair of MV images

  2. CT image reconstruction of steel pipe section from few projections using the method of rotating polar-coordinate

    International Nuclear Information System (INIS)

    Peng Shuaijun; Wu Zhifang

    2008-01-01

    Fast online inspection in steel pipe production is a big challenge. Radiographic CT imaging technology, a high performance non-destructive testing method, is quite appropriate for inspection and quality control of steel pipes. The method of rotating polar-coordinate is used to reconstruct the steel pipe section from few projections with the purpose of inspecting it online. It reduces the projection number needed and the data collection time, and accelerates the reconstruction algorithm and saves the inspection time evidently. The results of simulation experiment and actual experiment indicate that the image quality and reconstruction time of rotating polar-coordinate method meet the requirements of inspecting the steel tube section online basically. The study is of some theoretical significance and the method is expected to be widely used in practice. (authors)

  3. The University of Texas Institute for Geophysics' Marine Geology and Geophysics Field Course: A Hand-On Education Approach to Applied Geophysics

    Science.gov (United States)

    Davis, M. B.; Goff, J.; Gulick, S. P. S.; Fernandez, R.; Duncan, D.; Saustrup, S.

    2016-12-01

    The University of Texas Institute for Geophysics, Jackson School of Geosciences, offers a 3-week marine geology and geophysics field course. The course provides hands-on instruction and training for graduate and upper-level undergraduate students in high-resolution seismic reflection, CHIRP sub-bottom profiling, multibeam bathymetry, sidescan sonar, and sediment sampling and analysis. Students first participate in 3 days of classroom instruction designed to communicate geological context of the field area along with theoretical and technical background on each field method. The class then travels to the Gulf Coast for a week of at-sea field work at locations that provide an opportunity to investigate coastal and continental shelf processes. Teams of students rotate between UTIG's 26' R/V Scott Petty and NOAA's 82' R/V Manta. They assist with survey design, instrumentation set up, and learn about acquisition, quality control, and safe instrument deployment. Teams also process data and analyze samples in onshore field labs. During the final week teams integrate, interpret, and visualize data in a final project using industry-standard software. The course concludes with team presentations on their interpretations with academic and industry supporters. Students report a greater understanding of marine geology and geophysics through the course's intensive, hands-on, team approach and high instructor/student ratio (sixteen students, three faculty, and three teaching assistants). Post-class, students may incorporate course data in senior honors or graduate thesis and are encouraged to publish and present results at national meetings. This course (to our knowledge) remains the only one of its kind, satisfies field experience requirements for some degree programs, and provides an alternative to land-based field courses. Alumni note the course's applicability to energy, environmental, and geotechnical industries as well as coastal restoration/management fields.

  4. Geophysical Exploration of Tyuonyi Pueblo in Bandelier National Monument, New Mexico, USA

    Science.gov (United States)

    Sica, C.; Graham, D.; Peacock, E.; Suen, C.; Creighton, A.; Carchedi, C.; Feucht, D. W.; Civitello, J. A.; Jarret, J.; Martin, C.; Ferguson, J. F.; McPhee, D.; Pellerin, L.

    2017-12-01

    The Summer of Applied Geophysical Experience (SAGE) class of 2017 carried out near-surface geophysical investigations of the Tyuonyi Pueblo of Bandelier National Monument, New Mexico in order to aid trail planning and identification of archeological features that could potentially be impacted. Tyuonyi is located in Frijoles Canyon, carved by the Rito de los Frijoles, between the SE flank of the Jemez Mountains and the Rio Grande, and contains pueblo room blocks, kivas and cavates that were occupied by ancestral Puebloans between 1350 and 1550 CE. SAGE collected seismic refraction, magnetic, electromagnetic (EM) and GPR data along targeted profiles and grids north and east of Tyuonyi Pueblo. Two 30 X 30 m grids of GPR data were recorded along 1-m spaced lines using the 250 MHz Sensors and Software NOGGIN® 250 Smart Tow and processed using the EKKO Project V5 program. Seismic refraction data were collected using a 48-channel Geometrics Strataview recorder and seven spreads with 0.5 m geophone spacing, a 6 m shot point interval, and a hammer source. Shot point offsets between 0.5 m and 48 m provided overlapping subsurface coverage. Seismic data from SAGE 2016 and 2017 were merged into a 168 m-long profile. Magnetic data were collected along 1-m spaced N-S lines in two 30 X 30 m grids and along the seismic line using a Geometrics 858 cesium vapor magnetometer. In addition, EM data were collected using a Geonics, EM-31 system along the seismic line. A velocity model was created to fit the seismic travel times. The GPR images and seismic model can be used to interpret the Quaternary geology of the site. These data trace incision of the Rito de los Frijoles into the Bandelier Tuff over several stages of the canyon development. The seismic model indicates a number of narrow, shallow channels carved into a broader strath. Holocene alluvial terrace deposits overlie the Bandelier Tuff surface, and the Tyuonyi Pueblo was constructed on top of the highest terrace. On the north

  5. THERMAL IMAGING OF Si, GaAs AND GaN -BASED DEVICES WITHIN THE MICROTHERM PROJECT

    OpenAIRE

    Pavageau , S.; Tessier , G.; Filloy , C.; Jerosolimski , G.; Fournier , D.; Polignano , M.-L.; Mica , I.; Cassette , S.; Aubry , R.; Durand , O.

    2005-01-01

    Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/5920); International audience; Within the european project Microtherm, we have developed a CCD-based thermoreflectance system which delivers thermal images of working integrated circuits with high spatial and thermal resolutions (down to 350 nm and 0.1 K respectively). We illustrate the performances of this set-up on several classes of semiconductor devices including high power transistors and transistor ar...

  6. A Visual Database System for Image Analysis on Parallel Computers and its Application to the EOS Amazon Project

    Science.gov (United States)

    Shapiro, Linda G.; Tanimoto, Steven L.; Ahrens, James P.

    1996-01-01

    The goal of this task was to create a design and prototype implementation of a database environment that is particular suited for handling the image, vision and scientific data associated with the NASA's EOC Amazon project. The focus was on a data model and query facilities that are designed to execute efficiently on parallel computers. A key feature of the environment is an interface which allows a scientist to specify high-level directives about how query execution should occur.

  7. Geophysical observations at cavity collapse

    Science.gov (United States)

    Jousset, Philippe; Bazargan-Sabet, Behrooz; Lebert, François; Bernardie, Séverine; Gourry, Jean-Christophe

    2010-05-01

    In Lorraine region (France) salt layers at about 200 meters depth are exploited by Solvay using solution mining methodology which consists in extracting the salt by dissolution, collapsing the cavern overburden during the exploitation phase and finally reclaiming the landscape by creating a water area. In this process, one of the main challenges for the exploiting company is to control the initial 120-m diameter collapse so as to minimize possible damages. In order to detect potential precursors and understand processes associated with such collapses, a wide series of monitoring techniques including micro seismics, broad-band seismology, hydro-acoustic, electromagnetism, gas probing, automatic leveling, continuous GPS, continuous gravity and borehole extensometry was set-up in the frame of an in-situ study carried out by the "Research Group for the Impact and Safety of Underground Works" (GISOS, France). Equipments were set-up well before the final collapse, giving a unique opportunity to analyze a great deal of information prior to and during the collapse process which has been successfully achieved on February the 13th, 2009 by controlling the cavity internal pressure. In this work, we present the results of data recorded by a network of 3 broadband seismometers, 2 accelerometers, 2 tilt-meters and a continuously gravity meter. We relate the variations of the brine pumping rate with the evolutions of the induced geophysical signals and finally we propose a first mechanical model for describing the controlled collapse. Beyond the studied case, extrapolation of the results obtained might contribute to the understanding of uncontrolled cavity collapses, such as pit-craters or calderas at volcanoes.

  8. GeoFramework: A Modeling Framework for Solid Earth Geophysics

    Science.gov (United States)

    Gurnis, M.; Aivazis, M.; Tromp, J.; Tan, E.; Thoutireddy, P.; Liu, Q.; Choi, E.; Dicaprio, C.; Chen, M.; Simons, M.; Quenette, S.; Appelbe, B.; Aagaard, B.; Williams, C.; Lavier, L.; Moresi, L.; Law, H.

    2003-12-01

    As data sets in geophysics become larger and of greater relevance to other earth science disciplines, and as earth science becomes more interdisciplinary in general, modeling tools are being driven in new directions. There is now a greater need to link modeling codes to one another, link modeling codes to multiple datasets, and to make modeling software available to non modeling specialists. Coupled with rapid progress in computer hardware (including the computational speed afforded by massively parallel computers), progress in numerical algorithms, and the introduction of software frameworks, these lofty goals of merging software in geophysics are now possible. The GeoFramework project, a collaboration between computer scientists and geoscientists, is a response to these needs and opportunities. GeoFramework is based on and extends Pyre, a Python-based modeling framework, recently developed to link solid (Lagrangian) and fluid (Eulerian) models, as well as mesh generators, visualization packages, and databases, with one another for engineering applications. The utility and generality of Pyre as a general purpose framework in science is now being recognized. Besides its use in engineering and geophysics, it is also being used in particle physics and astronomy. Geology and geophysics impose their own unique requirements on software frameworks which are not generally available in existing frameworks and so there is a need for research in this area. One of the special requirements is the way Lagrangian and Eulerian codes will need to be linked in time and space within a plate tectonics context. GeoFramework has grown beyond its initial goal of linking a limited number of exiting codes together. The following codes are now being reengineered within the context of Pyre: Tecton, 3-D FE Visco-elastic code for lithospheric relaxation; CitComS, a code for spherical mantle convection; SpecFEM3D, a SEM code for global and regional seismic waves; eqsim, a FE code for dynamic

  9. Final report on LDRD project : single-photon-sensitive imaging detector arrays at 1600 nm

    International Nuclear Information System (INIS)

    Childs, Kenton David; Serkland, Darwin Keith; Geib, Kent Martin; Hawkins, Samuel D.; Carroll, Malcolm S.; Klem, John Frederick; Sheng, Josephine Juin-Jye; Patel, Rupal K.; Bolles, Desta; Bauer, Tom M.; Koudelka, Robert

    2006-01-01

    The key need that this project has addressed is a short-wave infrared light detector for ranging (LIDAR) imaging at temperatures greater than 100K, as desired by nonproliferation and work for other customers. Several novel device structures to improve avalanche photodiodes (APDs) were fabricated to achieve the desired APD performance. A primary challenge to achieving high sensitivity APDs at 1550 nm is that the small band-gap materials (e.g., InGaAs or Ge) necessary to detect low-energy photons exhibit higher dark counts and higher multiplication noise compared to materials like silicon. To overcome these historical problems APDs were designed and fabricated using separate absorption and multiplication (SAM) regions. The absorption regions used (InGaAs or Ge) to leverage these materials 1550 nm sensitivity. Geiger mode detection was chosen to circumvent gain noise issues in the III-V and Ge multiplication regions, while a novel Ge/Si device was built to examine the utility of transferring photoelectrons in a silicon multiplication region. Silicon is known to have very good analog and GM multiplication properties. The proposed devices represented a high-risk for high-reward approach. Therefore one primary goal of this work was to experimentally resolve uncertainty about the novel APD structures. This work specifically examined three different designs. An InGaAs/InAlAs Geiger mode (GM) structure was proposed for the superior multiplication properties of the InAlAs. The hypothesis to be tested in this structure was whether InAlAs really presented an advantage in GM. A Ge/Si SAM was proposed representing the best possible multiplication material (i.e., silicon), however, significant uncertainty existed about both the Ge material quality and the ability to transfer photoelectrons across the Ge/Si interface. Finally a third pure germanium GM structure was proposed because bulk germanium has been reported to have better dark count properties. However, significant

  10. Final report on LDRD project : single-photon-sensitive imaging detector arrays at 1600 nm.

    Energy Technology Data Exchange (ETDEWEB)

    Childs, Kenton David; Serkland, Darwin Keith; Geib, Kent Martin; Hawkins, Samuel D.; Carroll, Malcolm S.; Klem, John Frederick; Sheng, Josephine Juin-Jye; Patel, Rupal K.; Bolles, Desta; Bauer, Tom M.; Koudelka, Robert

    2006-11-01

    The key need that this project has addressed is a short-wave infrared light detector for ranging (LIDAR) imaging at temperatures greater than 100K, as desired by nonproliferation and work for other customers. Several novel device structures to improve avalanche photodiodes (APDs) were fabricated to achieve the desired APD performance. A primary challenge to achieving high sensitivity APDs at 1550 nm is that the small band-gap materials (e.g., InGaAs or Ge) necessary to detect low-energy photons exhibit higher dark counts and higher multiplication noise compared to materials like silicon. To overcome these historical problems APDs were designed and fabricated using separate absorption and multiplication (SAM) regions. The absorption regions used (InGaAs or Ge) to leverage these materials 1550 nm sensitivity. Geiger mode detection was chosen to circumvent gain noise issues in the III-V and Ge multiplication regions, while a novel Ge/Si device was built to examine the utility of transferring photoelectrons in a silicon multiplication region. Silicon is known to have very good analog and GM multiplication properties. The proposed devices represented a high-risk for high-reward approach. Therefore one primary goal of this work was to experimentally resolve uncertainty about the novel APD structures. This work specifically examined three different designs. An InGaAs/InAlAs Geiger mode (GM) structure was proposed for the superior multiplication properties of the InAlAs. The hypothesis to be tested in this structure was whether InAlAs really presented an advantage in GM. A Ge/Si SAM was proposed representing the best possible multiplication material (i.e., silicon), however, significant uncertainty existed about both the Ge material quality and the ability to transfer photoelectrons across the Ge/Si interface. Finally a third pure germanium GM structure was proposed because bulk germanium has been reported to have better dark count properties. However, significant

  11. A sparsity-based iterative algorithm for reconstruction of micro-CT images from highly undersampled projection datasets obtained with a synchrotron X-ray source

    Science.gov (United States)

    Melli, S. Ali; Wahid, Khan A.; Babyn, Paul; Cooper, David M. L.; Gopi, Varun P.

    2016-12-01

    Synchrotron X-ray Micro Computed Tomography (Micro-CT) is an imaging technique which is increasingly used for non-invasive in vivo preclinical imaging. However, it often requires a large number of projections from many different angles to reconstruct high-quality images leading to significantly high radiation doses and long scan times. To utilize this imaging technique further for in vivo imaging, we need to design reconstruction algorithms that reduce the radiation dose and scan time without reduction of reconstructed image quality. This research is focused on using a combination of gradient-based Douglas-Rachford splitting and discrete wavelet packet shrinkage image denoising methods to design an algorithm for reconstruction of large-scale reduced-view synchrotron Micro-CT images with acceptable quality metrics. These quality metrics are computed by comparing the reconstructed images with a high-dose reference image reconstructed from 1800 equally spaced projections spanning 180°. Visual and quantitative-based performance assessment of a synthetic head phantom and a femoral cortical bone sample imaged in the biomedical imaging and therapy bending magnet beamline at the Canadian Light Source demonstrates that the proposed algorithm is superior to the existing reconstruction algorithms. Using the proposed reconstruction algorithm to reduce the number of projections in synchrotron Micro-CT is an effective way to reduce the overall radiation dose and scan time which improves in vivo imaging protocols.

  12. Optimal image alignment with random projections of manifolds: algorithm and geometric analysis.

    Science.gov (United States)

    Kokiopoulou, Effrosyni; Kressner, Daniel; Frossard, Pascal

    2011-06-01

    This paper addresses the problem of image alignment based on random measurements. Image alignment consists of estimating the relative transformation between a query image and a reference image. We consider the specific problem where the query image is provided in compressed form in terms of linear measurements captured by a vision sensor. We cast the alignment problem as a manifold distance minimization problem in the linear subspace defined by the measurements. The transformation manifold that represents synthesis of shift, rotation, and isotropic scaling of the reference image can be given in closed form when the reference pattern is sparsely represented over a parametric dictionary. We show that the objective function can then be decomposed as the difference of two convex functions (DC) in the particular case where the dictionary is built on Gaussian functions. Thus, the optimization problem becomes a DC program, which in turn can be solved globally by a cutting plane method. The quality of the solution is typically affected by the number of random measurements and the condition number of the manifold that describes the transformations of the reference image. We show that the curvature, which is closely related to the condition number, remains bounded in our image alignment problem, which means that the relative transformation between two images can be determined optimally in a reduced subspace.

  13. MR-guided PET motion correction in LOR space using generic projection data for image reconstruction with PRESTO

    International Nuclear Information System (INIS)

    Scheins, J.; Ullisch, M.; Tellmann, L.; Weirich, C.; Rota Kops, E.; Herzog, H.; Shah, N.J.

    2013-01-01

    The BrainPET scanner from Siemens, designed as hybrid MR/PET system for simultaneous acquisition of both modalities, provides high-resolution PET images with an optimum resolution of 3 mm. However, significant head motion often compromises the achievable image quality, e.g. in neuroreceptor studies of human brain. This limitation can be omitted when tracking the head motion and accurately correcting measured Lines-of-Response (LORs). For this purpose, we present a novel method, which advantageously combines MR-guided motion tracking with the capabilities of the reconstruction software PRESTO (PET Reconstruction Software Toolkit) to convert motion-corrected LORs into highly accurate generic projection data. In this way, the high-resolution PET images achievable with PRESTO can also be obtained in presence of severe head motion

  14. Reflections from a Creative Community-Based Participatory Research Project Exploring Health and Body Image with First Nations Girls

    Directory of Open Access Journals (Sweden)

    Jennifer M. Shea PhD

    2013-02-01

    Full Text Available In Canada, Aboriginal peoples often experience a multitude of inequalities when compared with the general population, particularly in relation to health (e.g., increased incidence of diabetes. These inequalities are rooted in a negative history of colonization. Decolonizing methodologies recognize these realities and aim to shift the focus from communities being researched to being collaborative partners in the research process. This article describes a qualitative community-based participatory research project focused on health and body image with First Nations girls in a Tribal Council region in Western Canada. We discuss our project design and the incorporation of creative methods (e.g., photovoice to foster integration and collaboration as related to decolonizing methodology principles. This article is both descriptive and reflective as it summarizes our project and discusses lessons learned from the process, integrating evaluations from the participating girls as well as our reflections as researchers.

  15. Comparison of Geophysical Model Functions for SAR Wind Speed Retrieval in Japanese Coastal Waters

    DEFF Research Database (Denmark)

    Takeyama, Yuko; Ohsawa, Teruo; Kozai, Katsutoshi

    2013-01-01

    This work discusses the accuracies of geophysical model functions (GMFs) for retrieval of sea surface wind speed from satellite-borne Synthetic Aperture Radar (SAR) images in Japanese coastal waters characterized by short fetches and variable atmospheric stability conditions. In situ observations...

  16. New determination of period and quality factor of Chandler wobble, considering geophysical excitations

    Czech Academy of Sciences Publication Activity Database

    Vondrák, Jan; Ron, Cyril; Chapanov, Y.

    2017-01-01

    Roč. 59, č. 5 (2017), s. 1395-1407 ISSN 0273-1177 R&D Projects: GA ČR GA13-15943S Institutional support: RVO:67985815 Keywords : polar motion * chandler wobble * geophysical excitations Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 1.401, year: 2016

  17. Characteristics of Sounds Emitted During High-Resolution Marine Geophysical Surveys

    Science.gov (United States)

    2016-03-24

    Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law , no person shall be...marine transportation , oil and gas, marine mineral, and renewable energy projects. In particular, geophysical surveys support infrastructure siting...sand resource delineation, geomorphic characterization, environmental monitoring, archaeological resource identification, and mapping of shallow

  18. Methodological Developments in Geophysical Assimilation Modeling

    Science.gov (United States)

    Christakos, George

    2005-06-01

    This work presents recent methodological developments in geophysical assimilation research. We revisit the meaning of the term "solution" of a mathematical model representing a geophysical system, and we examine its operational formulations. We argue that an assimilation solution based on epistemic cognition (which assumes that the model describes incomplete knowledge about nature and focuses on conceptual mechanisms of scientific thinking) could lead to more realistic representations of the geophysical situation than a conventional ontologic assimilation solution (which assumes that the model describes nature as is and focuses on form manipulations). Conceptually, the two approaches are fundamentally different. Unlike the reasoning structure of conventional assimilation modeling that is based mainly on ad hoc technical schemes, the epistemic cognition approach is based on teleologic criteria and stochastic adaptation principles. In this way some key ideas are introduced that could open new areas of geophysical assimilation to detailed understanding in an integrated manner. A knowledge synthesis framework can provide the rational means for assimilating a variety of knowledge bases (general and site specific) that are relevant to the geophysical system of interest. Epistemic cognition-based assimilation techniques can produce a realistic representation of the geophysical system, provide a rigorous assessment of the uncertainty sources, and generate informative predictions across space-time. The mathematics of epistemic assimilation involves a powerful and versatile spatiotemporal random field theory that imposes no restriction on the shape of the probability distributions or the form of the predictors (non-Gaussian distributions, multiple-point statistics, and nonlinear models are automatically incorporated) and accounts rigorously for the uncertainty features of the geophysical system. In the epistemic cognition context the assimilation concept may be used to

  19. The utility of three-dimensional optical projection tomography in nerve injection injury imaging

    Czech Academy of Sciences Publication Activity Database

    Cvetko, E.; Čapek, Martin; Damjanovska, M.; Reina, M. A.; Eržen, I.; Stopar-Pintarič, T.

    2015-01-01

    Roč. 70, č. 8 (2015), s. 939-947 ISSN 0003-2409 R&D Projects: GA ČR(CZ) GA13-12412S; GA MŠk(CZ) LH13028 Institutional support: RVO:67985823 Keywords : optical projection tomography * 3D nerve visualization * nerve disruption Subject RIV: EA - Cell Biology Impact factor: 3.794, year: 2015

  20. Geophysical observations and prediction of geophysical fields for users

    Czech Academy of Sciences Publication Activity Database

    Bochníček, Josef; Laštovička, Jan; Schenk, Vladimír; Boška, Josef; Burešová, Dalia; Hejda, Pavel; Horáček, Josef; Kottnauer, Pavel; Križan, Peter; Nejedlá, Jaroslava; Růžek, Bohuslav; Schenková, Zdeňka; Šauli, Petra; Zedník, Jan

    -, č. 14 (2005), s. 51-59 ISSN 1214-9691 R&D Projects: GA AV ČR IBS3012007 Institutional research plan: CEZ:AV0Z30120515 Keywords : geomagnetism * ionosphere * seismology Subject RIV: DC - Siesmology, Volcanology, Earth Structure

  1. Geophysics: Building E5481 decommissioning, Aberdeen Proving Ground

    International Nuclear Information System (INIS)

    Thompson, M.D.; McGinnis, M.G.; McGinnis, L.D.; Miller, S.F.

    1992-11-01

    Building E5481 is one of ten potentially contaminated sites in the Canal Creek and Westwood areas of the Edgewood section of Aberdeen Proving Ground examined by a geophysical team from Argonne National Laboratory in April and May of 1992. Noninvasive geophysical surveys, including magnetics, electrical resistivity, and ground-penetrating radar, were conducted around the perimeter of the building to guide a sampling program prior to decommissioning and dismantling. The building is located on the northern margin of a landfill that was sited in a wetland. The large number of magnetic sources surrounding the building are believed to be contained in construction fill that had been used to raise the grade. The smaller anomalies, for the most part, are not imaged with ground radar or by electrical profiling. A conductive zone trending northwest to southeast across the site is spatially related to an old roadbed. Higher resistivity areas in the northeast and east are probably representive of background values. Three high-amplitude, positive, rectangular magnetic anomalies have unknown sources. The features do not have equivalent electrical signatures, nor are they seen with radar imaging

  2. Implementation of a dedicated digital projectional radiographic system in thoracic imaging

    International Nuclear Information System (INIS)

    Aberle, D.R.; Batra, P.; Hayrapetian, A.S.; Brown, K.; Morioka, C.A.; Steckel, R.J.

    1988-01-01

    An integrated digital radiographic system was evaluated with respect to image quality and impact on diagnosis relative to conventional chest radiographs for a variety of focal and diffuse lung processes. Digital images were acquired with a stimulable phosphor plate detector that was scanned by a semiconductor laser for immediate digitalization to a 2,048 X 2,464 X 10-bit image. Digital images were displayed on a 2,048-line monitor and printed on 14 X 17-inch film with use of a laser film printer (Kodak). Preliminary results with this system, including the effects of user interaction with the display monitor, inverse intensity display, and regional magnification techniques, indicate that it may be successfully implemented for thoracic imaging

  3. Methods and applications of radio frequency geophysics in glaciology

    Science.gov (United States)

    Holschuh, Nicholas

    Simple radar systems of the past were used primarily for radar depth sounding, the process of using reflection travel times and electromagnetic velocities to determine the ice thickness. Modern radioglaciology uses both the travel times and reflection amplitudes to make inferences about the englacial and subglacial environments; however, non-uniqueness in geophysical data, combined with the large number of physical parameters that control reflection amplitude, have led to significant uncertainties in this type of analysis. In this set of studies, I improve on data collection, processing, and assimilation methods, with a focus on radar reflection amplitudes and internal layers. The first two studies are devoted to radar survey methods, in which I examine the impact of reflector geometry on amplitude (2), and investigate an independent measure of radar attenuation using variable-offset data, in an effort to eliminate the effects of ice chemistry and temperature on reflection amplitudes (3). These studies emphasize the fact that radar data are a product of both the physical system and the imaging process, and caution glaciologists from over-interpreting processing artifacts common in radar data collected in areas of complex glacial flow. In the following two chapters, I go on to provide glaciological applications of processed radar data, interpreting the record of complex flow left behind in englacial reflector slopes (4), and applying improved boundary conditions to better predict the maximum extent of West Antarctic collapse (5). These studies use geometric information from the bed reflector and englacial reflectors to describe the flow regime present in Antarctica today. Chapter 4 examines how boundary conditions that are difficult to observe directly (the geothermal heat flux, as well as the frictional and deformation characteristics of the ice-sheet substrate) manifest through internal layer deformation. Chapter 5 focuses on Marie Byrd Land (MBL), where

  4. Exotic geophysical phenomena observed in an environmental neutron flux study using EAS PRISMA detectors

    Directory of Open Access Journals (Sweden)

    Alekseenko Victor

    2017-01-01

    Full Text Available Some exotic geophysical events are observed by a global net of electron-neutron detectors (en-detectors developed in the framework of the PRISMA EAS project. Our en-detectors running both on the Earth's surface and underground are continuously measuring the environmental thermal neutron flux. Thermal neutrons are in equilibrium with media and are therefore sensitive to many geophysical phenomena, which are exotic for people studying ultra high-energy cosmic rays or carrying out low background experiments deep underground.

  5. The PixFEL project: Progress towards a fine pitch X-ray imaging camera for next generation FEL facilities

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, G., E-mail: giuliana.rizzo@pi.infn.it [Università di Pisa, Dipartimento di Fisica, I-56127 Pisa (Italy); INFN, Sezione di Pisa, I-56127 Pisa (Italy); Batignani, G. [Università di Pisa, Dipartimento di Fisica, I-56127 Pisa (Italy); INFN, Sezione di Pisa, I-56127 Pisa (Italy); Benkechkache, M.A. [Università di Trento, Dipartimento di Ingegneria Industriale, I-38123 Trento (Italy); University Constantine 1, Department of Electronics in the Science and Technology Faculty, I-25017, Constantine (Algeria); Bettarini, S.; Casarosa, G. [Università di Pisa, Dipartimento di Fisica, I-56127 Pisa (Italy); INFN, Sezione di Pisa, I-56127 Pisa (Italy); Comotti, D. [Università di Pavia, Dipartimento di Ingegneria Industriale e dell' Informazione, I-27100 Pavia (Italy); INFN Sezione di Pavia, I-27100 Pavia (Italy); Dalla Betta, G.-F. [Università di Trento, Dipartimento di Ingegneria Industriale, I-38123 Trento (Italy); TIFPA INFN, I-38123 Trento (Italy); Fabris, L. [INFN Sezione di Pavia, I-27100 Pavia (Italy); Università di Bergamo, Dipartimento di Ingegneria e Scienze Applicate, I-24044 Dalmine (Italy); Forti, F. [Università di Pisa, Dipartimento di Fisica, I-56127 Pisa (Italy); INFN, Sezione di Pisa, I-56127 Pisa (Italy); Grassi, M.; Lodola, L.; Malcovati, P. [Università di Pavia, Dipartimento di Ingegneria Industriale e dell' Informazione, I-27100 Pavia (Italy); INFN Sezione di Pavia, I-27100 Pavia (Italy); Manghisoni, M. [INFN Sezione di Pavia, I-27100 Pavia (Italy); Università di Bergamo, Dipartimento di Ingegneria e Scienze Applicate, I-24044 Dalmine (Italy); and others

    2016-07-11

    The INFN PixFEL project is developing the fundamental building blocks for a large area X-ray imaging camera to be deployed at next generation free electron laser (FEL) facilities with unprecedented intensity. Improvement in performance beyond the state of art in imaging instrumentation will be explored adopting advanced technologies like active edge sensors, a 65 nm node CMOS process and vertical integration. These are the key ingredients of the PixFEL project to realize a seamless large area focal plane instrument composed by a matrix of multilayer four-side buttable tiles. In order to minimize the dead area and reduce ambiguities in image reconstruction, a fine pitch active edge thick sensor is being optimized to cope with very high intensity photon flux, up to 10{sup 4} photons per pixel, in the range from 1 to 10 keV. A low noise analog front-end channel with this wide dynamic range and a novel dynamic compression feature, together with a low power 10 bit analog to digital conversion up to 5 MHz, has been realized in a 110 μm pitch with a 65 nm CMOS process. Vertical interconnection of two CMOS tiers will be also explored in the future to build a four-side buttable readout chip with high density memories. In the long run the objective of the PixFEL project is to build a flexible X-ray imaging camera for operation both in burst mode, like at the European X-FEL, or in continuous mode with the high frame rates anticipated for future FEL facilities.

  6. The PixFEL project: Progress towards a fine pitch X-ray imaging camera for next generation FEL facilities

    International Nuclear Information System (INIS)

    Rizzo, G.; Batignani, G.; Benkechkache, M.A.; Bettarini, S.; Casarosa, G.; Comotti, D.; Dalla Betta, G.-F.; Fabris, L.; Forti, F.; Grassi, M.; Lodola, L.; Malcovati, P.; Manghisoni, M.

    2016-01-01

    The INFN PixFEL project is developing the fundamental building blocks for a large area X-ray imaging camera to be deployed at next generation free electron laser (FEL) facilities with unprecedented intensity. Improvement in performance beyond the state of art in imaging instrumentation will be explored adopting advanced technologies like active edge sensors, a 65 nm node CMOS process and vertical integration. These are the key ingredients of the PixFEL project to realize a seamless large area focal plane instrument composed by a matrix of multilayer four-side buttable tiles. In order to minimize the dead area and reduce ambiguities in image reconstruction, a fine pitch active edge thick sensor is being optimized to cope with very high intensity photon flux, up to 10"4 photons per pixel, in the range from 1 to 10 keV. A low noise analog front-end channel with this wide dynamic range and a novel dynamic compression feature, together with a low power 10 bit analog to digital conversion up to 5 MHz, has been realized in a 110 μm pitch with a 65 nm CMOS process. Vertical interconnection of two CMOS tiers will be also explored in the future to build a four-side buttable readout chip with high density memories. In the long run the objective of the PixFEL project is to build a flexible X-ray imaging camera for operation both in burst mode, like at the European X-FEL, or in continuous mode with the high frame rates anticipated for future FEL facilities.

  7. Identification of retinal ganglion cells and their projections involved in central transmission of information about upward and downward image motion.

    Directory of Open Access Journals (Sweden)

    Keisuke Yonehara

    Full Text Available The direction of image motion is coded by direction-selective (DS ganglion cells in the retina. Particularly, the ON DS ganglion cells project their axons specifically to terminal nuclei of the accessory optic system (AOS responsible for optokinetic reflex (OKR. We recently generated a knock-in mouse in which SPIG1 (SPARC-related protein containing immunoglobulin domains 1-expressing cells are visualized with GFP, and found that retinal ganglion cells projecting to the medial terminal nucleus (MTN, the principal nucleus of the AOS, are comprised of SPIG1+ and SPIG1(- ganglion cells distributed in distinct mosaic patterns in the retina. Here we examined light responses of these two subtypes of MTN-projecting cells by targeted electrophysiological recordings. SPIG1+ and SPIG1(- ganglion cells respond preferentially to upward motion and downward motion, respectively, in the visual field. The direction selectivity of SPIG1+ ganglion cells develops normally in dark-reared mice. The MTN neurons are activated by optokinetic stimuli only of the vertical motion as shown by Fos expression analysis. Combination of genetic labeling and conventional retrograde labeling revealed that axons of SPIG1+ and SPIG1(- ganglion cells project to the MTN via different pathways. The axon terminals of the two subtypes are organized into discrete clusters in the MTN. These results suggest that information about upward and downward image motion transmitted by distinct ON DS cells is separately processed in the MTN, if not independently. Our findings provide insights into the neural mechanisms of OKR, how information about the direction of image motion is deciphered by the AOS.

  8. Under the pile. Understanding subsurface dynamics of historical cities trough geophysical models interpretation

    Science.gov (United States)

    Bernardes, Paulo; Pereira, Bruno; Alves, Mafalda; Fontes, Luís; Sousa, Andreia; Martins, Manuela; Magalhães, Fernanda; Pimenta, Mário

    2017-04-01

    Braga is one of the oldest cities of the Iberian NW and as of so, the research team's studying the city's historical core for the past 40 years is often confronted with the unpredictability factor laying beneath an urban site with such a long construction history. In fact, Braga keeps redesigning its urban structure over itself on for the past 2000 years, leaving us with a research object filled with an impressive set of construction footprints from the various planning decisions that were taken in the city along its historical path. Aiming for a predicting understanding of the subsoil, we have used near surface geophysics as an effort of minimizing the areas of intervention for traditional archaeological survey techniques. The Seminário de Santiago integrated geophysical survey is an example of the difficulties of interpreting geophysical models in very complex subsurface scenarios. This geophysical survey was planned in order to aid the requalification project being designed for this set of historical buildings, that are estimated to date back to the 16h century, and that were built over one of the main urban arteries of both roman and medieval layers of Braga. We have used both GPR as well as ERT methods for the geophysical survey, but for the purpose of this article, we will focus in the use of the ERT alone. For the interpretation of the geophysical models we've cross-referenced the dense knowledge existing over the building's construction phases with the complex geophysical data collected, using mathematical processing and volume-based visualization techniques, resorting to the use of Res2Inv©, Paraview© and Voxler® software's. At the same time we tried to pinpoint the noise caused by the past 30 year's infrastructural interventions regarding the replacement of the building's water and sanitation systems and for which we had no design plants, regardless of its recent occurring. The deep impact of this replacement actions revealed by the archaeological

  9. Chaos theory in geophysics: past, present and future

    International Nuclear Information System (INIS)

    Sivakumar, B.

    2004-01-01

    The past two decades of research on chaos theory in geophysics has brought about a significant shift in the way we view geophysical phenomena. Research on chaos theory in geophysics continues to grow at a much faster pace, with applications to a wide variety of geophysical phenomena and geophysical problems. In spite of our success in understanding geophysical phenomena also from a different (i.e. chaotic) perspective, there still seems to be lingering suspicions on the scope of chaos theory in geophysics. The goal of this paper is to present a comprehensive account of the achievements and status of chaos theory in geophysics, and to disseminate the hope and scope for the future. A systematic review of chaos theory in geophysics, covering a wide spectrum of geophysical phenomena studied (e.g. rainfall, river flow, sediment transport, temperature, pressure, tree ring series, etc.), is presented to narrate our past achievements not only in understanding and predicting geophysical phenomena but also in improving the chaos identification and prediction techniques. The present state of chaos research in geophysics (in terms of geophysical phenomena, problems, and chaos methods) and potential for future improvements (in terms of where, why and possibly how) are also highlighted. Our popular views of nature (i.e. stochastic and deterministic), and of geophysical phenomena in particular, are discussed, and the usefulness of chaos theory as a bridge between such views is also put forth

  10. Looking Forward to the electronic Geophysical Year

    Science.gov (United States)

    Kamide, Y.; Baker, D. N.; Thompson, B.; Barton, C.; Kihn, E.

    2004-12-01

    During the International Geophysical Year (1957-1958), member countries established many new capabilities pursuing the major IGY objectives of collecting geophysical data as widely as possible and providing free access to these data for all scientists around the globe. A key achievement of the IGY was the establishment of a worldwide system of data centers and physical observatories. The worldwide scientific community has now endorsed and is promoting an electronic Geophysical Year (eGY) initiative. The proposed eGY concept would both commemorate the 50th anniversary of the IGY in 2007-2008 and would provide a forward impetus to geophysics in the 21st century, similar to that provide by the IGY fifty years ago. The eGY concept advocates the establishment of a series of virtual geophysical observatories now being deployed in cyberspace. We discuss plans to aggregate measurements into a readily accessible database along with analysis, visualization, and display tools that will make information available and useful to the scientific community, to the user community, and to the general public. We are examining the possibilities for near-realtime acquisition of data and utilization of forecast tools in order to provide users with advanced space weather capabilities. This program will provide powerful tools for education and public outreach concerning the connected Sun-Earth System.

  11. Deployment of a Prototype Plant GFP Imager at the Arthur Clarke Mars Greenhouse of the Haughton Mars Project

    Directory of Open Access Journals (Sweden)

    Robert J. Ferl

    2008-04-01

    Full Text Available The use of engineered plants as biosensors has made elegant strides in the past decades, providing keen insights into the health of plants in general and particularly in the nature and cellular location of stress responses. However, most of the analytical procedures involve laboratory examination of the biosensor plants. With the advent of the green fluorescence protein (GFP as a biosensor molecule, it became at least theoretically possible for analyses of gene expression to occur telemetrically, with the gene expression information of the plant delivered to the investigator over large distances simply as properly processed fluorescence images. Spaceflight and other extraterrestrial environments provide unique challenges to plant life, challenges that often require changes at the gene expression level to accommodate adaptation and survival. Having previously deployed transgenic plant biosensors to evaluate responses to orbital spaceflight, we wished to develop the plants and especially the imaging devices required to conduct such experiments robotically, without operator intervention, within extraterrestrial environments. This requires the development of an autonomous and remotely operated plant GFP imaging system and concomitant development of the communications infrastructure to manage dataflow from the imaging device. Here we report the results of deploying a prototype GFP imaging system within the Arthur Clarke Mars Greenhouse (ACMG an autonomously operated greenhouse located within the Haughton Mars Project in the Canadian High Arctic. Results both demonstrate the applicability of the fundamental GFP biosensor technology and highlight the difficulties in collecting and managing telemetric data from challenging deployment environments.

  12. System and technique for retrieving depth information about a surface by projecting a composite image of modulated light patterns

    Science.gov (United States)

    Hassebrook, Laurence G. (Inventor); Lau, Daniel L. (Inventor); Guan, Chun (Inventor)

    2010-01-01

    A technique, associated system and program code, for retrieving depth information about at least one surface of an object, such as an anatomical feature. Core features include: projecting a composite image comprising a plurality of modulated structured light patterns, at the anatomical feature; capturing an image reflected from the surface; and recovering pattern information from the reflected image, for each of the modulated structured light patterns. Pattern information is preferably recovered for each modulated structured light pattern used to create the composite, by performing a demodulation of the reflected image. Reconstruction of the surface can be accomplished by using depth information from the recovered patterns to produce a depth map/mapping thereof. Each signal waveform used for the modulation of a respective structured light pattern, is distinct from each of the other signal waveforms used for the modulation of other structured light patterns of a composite image; these signal waveforms may be selected from suitable types in any combination of distinct signal waveforms, provided the waveforms used are uncorrelated with respect to each other. The depth map/mapping to be utilized in a host of applications, for example: displaying a 3-D view of the object; virtual reality user-interaction interface with a computerized device; face--or other animal feature or inanimate object--recognition and comparison techniques for security or identification purposes; and 3-D video teleconferencing/telecollaboration.

  13. Evidence for a critical Earth: the New Geophysics

    Science.gov (United States)

    Crampin, Stuart; Gao, Yuan

    2015-04-01

    Phenomena that are critical-systems verging on criticality with 'butterfly wings' sensitivity are common - the weather, climate change; stellar radiation; the New York Stock Exchange; population explosions; population collapses; the life cycle of fruit-flies; and many more. It must be expected that the Earth, an archetypal complex heterogeneous interactive phenomena, is a critical-system, hence there is a New Geophysics imposing fundamentally new properties on conventional sub-critical geophysics. We shall show that, despite shear waves and shear-wave splitting (SWS) being observationally neglected, azimuthally-varying stress-aligned SWS is nearly universally observed throughout the Earth's crust and uppermost ~400km of the mantle. Caused by stress-aligned fluid-saturated microcracks (intergranular films of hydrolysed melt in the mantle), the microcracks are so closely-spaced that they verge on failure in fracturing and earthquakes. Phenomena that verge on failure in this way are critical-systems which impose a range of fundamental-new properties on conventional sub-critical geophysics including: self-similarity; monitorability; calculability; predictability; controllability; universality; and butterfly wings' sensitivity. We shall show how these phenomena have been consistently observed along millions of source-to-receiver ray paths confirming the New Geophysics. New Geophysics helps to explain many otherwise inexplicable observations including a number of geophysical conundrums such as the Gutenberg-Richter relationship which is used to describe the behaviour of conventional classic geophysics despite being massively non-linear. The great advantage of the critical Earth is that, unlike other critical-systems, the progress towards criticality can be monitored at almost any point within the deep interior of the material, by analysing observations of seismic SWS. This gives an unrivalled understanding of the detailed behaviour of a particular critical-system. This

  14. Massive Sulphide Exploration at the Mid-Atlantic Ridge 26oN: an interdisciplinary geophysical study

    Science.gov (United States)

    Gehrmann, R. A. S.; Hölz, S.; Jegen, M. D.; Graber, S.; Szitkar, F.; Petersen, S.; Yeo, I. A.; North, L. J.; Gil, A.; Vardy, M. E.; Haroon, A.; Schroeder, H.; Bialas, J.; Tan, Y. Y.; Attias, E.; Sommer, M.; Minshull, T. A.; Murton, B. J.

    2017-12-01

    During the summer 2016 two cruises (M127 and JC138) conducted an interdisciplinary survey as part of the EU FP7 project `Blue Mining' in the Trans-Atlantic Geotraverse (TAG) hydrothermal field, at the Mid-Atlantic Ridge (26° N), to study the geophysical and geochemical signature of extinct seafloor massive sulphide (eSMS) deposits. The survey comprised AUV-based high-resolution bathymetric mapping, magnetic and self-potential data acquisition, reflection and refraction seismic imaging and three types of controlled source electromagnetic (CSEM) experiments (Geomar, UoS). Additionally seafloor coring, drilling and video imaging (NOC, University of Lisbon, BGS) were realized. Laboratory measurements of physical and chemical properties were taken on and post-cruise from rock samples and sediment cores. Here, we present results from the geophysical data analysis with emphasis on the electromagnetic studies in respect to eSMS detection. Six multi-kilometre-long profiles were acquired with the towed CSEM experiment (UoS) and preliminary results indicate the sensitivity to the conductive eSMS deposits and the resistive background to a depth of about 200 m. The system is also sensitive to the rough topography and interpretation of eSMS deposits requires validation from other methods such as measurements with the MARTEMIS system, a seafloor source-receiver coil (Geomar), which were conducted in two collocated work areas for high-resolution imaging with a depth penetration of up to 50 m. Each geophysical method is sensitive to different SMS characteristics, for example, bathymetric and seismic data are sensitive to the shape and structure of the whole deposit, magnetic data are susceptive to the hydrothermal alteration of magnetic minerals, and self-potential and electromagnetic data respond to the electrically conductive sulphide bodies. Each method has different resolution, penetration depths and challenges with the rough-topographic terrain and navigation. Only

  15. 3D palmprint and hand imaging system based on full-field composite color sinusoidal fringe projection technique.

    Science.gov (United States)

    Zhang, Zonghua; Huang, Shujun; Xu, Yongjia; Chen, Chao; Zhao, Yan; Gao, Nan; Xiao, Yanjun

    2013-09-01

    Palmprint and hand shape, as two kinds of important biometric characteristics, have been widely studied and applied to human identity recognition. The existing research is based mainly on 2D images, which lose the third-dimensional information. The biological features extracted from 2D images are distorted by pressure and rolling, so the subsequent feature matching and recognition are inaccurate. This paper presents a method to acquire accurate 3D shapes of palmprint and hand by projecting full-field composite color sinusoidal fringe patterns and the corresponding color texture information. A 3D imaging system is designed to capture and process the full-field composite color fringe patterns on hand surface. Composite color fringe patterns having the optimum three fringe numbers are generated by software and projected onto the surface of human hand by a digital light processing projector. From another viewpoint, a color CCD camera captures the deformed fringe patterns and saves them for postprocessing. After compensating for the cross talk and chromatic aberration between color channels, three fringe patterns are extracted from three color channels of a captured composite color image. Wrapped phase information can be calculated from the sinusoidal fringe patterns with high precision. At the same time, the absolute phase of each pixel is determined by the optimum three-fringe selection method. After building up the relationship between absolute phase map and 3D shape data, the 3D palmprint and hand are obtained. Color texture information can be directly captured or demodulated from the captured composite fringe pattern images. Experimental results show that the proposed method and system can yield accurate 3D shape and color texture information of the palmprint and hand shape.

  16. Image quality in thoracic 4D cone-beam CT: A sensitivity analysis of respiratory signal, binning method, reconstruction algorithm, and projection angular spacing

    International Nuclear Information System (INIS)

    Shieh, Chun-Chien; Kipritidis, John; O’Brien, Ricky T.; Keall, Paul J.; Kuncic, Zdenka

    2014-01-01

    Purpose: Respiratory signal, binning method, and reconstruction algorithm are three major controllable factors affecting image quality in thoracic 4D cone-beam CT (4D-CBCT), which is widely used in image guided radiotherapy (IGRT). Previous studies have investigated each of these factors individually, but no integrated sensitivity analysis has been performed. In addition, projection angular spacing is also a key factor in reconstruction, but how it affects image quality is not obvious. An investigation of the impacts of these four factors on image quality can help determine the most effective strategy in improving 4D-CBCT for IGRT. Methods: Fourteen 4D-CBCT patient projection datasets with various respiratory motion features were reconstructed with the following controllable factors: (i) respiratory signal (real-time position management, projection image intensity analysis, or fiducial marker tracking), (ii) binning method (phase, displacement, or equal-projection-density displacement binning), and (iii) reconstruction algorithm [Feldkamp–Davis–Kress (FDK), McKinnon–Bates (MKB), or adaptive-steepest-descent projection-onto-convex-sets (ASD-POCS)]. The image quality was quantified using signal-to-noise ratio (SNR), contrast-to-noise ratio, and edge-response width in order to assess noise/streaking and blur. The SNR values were also analyzed with respect to the maximum, mean, and root-mean-squared-error (RMSE) projection angular spacing to investigate how projection angular spacing affects image quality. Results: The choice of respiratory signals was found to have no significant impact on image quality. Displacement-based binning was found to be less prone to motion artifacts compared to phase binning in more than half of the cases, but was shown to suffer from large interbin image quality variation and large projection angular gaps. Both MKB and ASD-POCS resulted in noticeably improved image quality almost 100% of the time relative to FDK. In addition, SNR

  17. Image quality in thoracic 4D cone-beam CT: A sensitivity analysis of respiratory signal, binning method, reconstruction algorithm, and projection angular spacing

    Energy Technology Data Exchange (ETDEWEB)

    Shieh, Chun-Chien [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, NSW 2006, Australia and Institute of Medical Physics, School of Physics, University of Sydney, NSW 2006 (Australia); Kipritidis, John; O’Brien, Ricky T.; Keall, Paul J., E-mail: paul.keall@sydney.edu.au [Radiation Physics Laboratory, Sydney Medical School, University of Sydney, NSW 2006 (Australia); Kuncic, Zdenka [Institute of Medical Physics, School of Physics, University of Sydney, NSW 2006 (Australia)

    2014-04-15

    Purpose: Respiratory signal, binning method, and reconstruction algorithm are three major controllable factors affecting image quality in thoracic 4D cone-beam CT (4D-CBCT), which is widely used in image guided radiotherapy (IGRT). Previous studies have investigated each of these factors individually, but no integrated sensitivity analysis has been performed. In addition, projection angular spacing is also a key factor in reconstruction, but how it affects image quality is not obvious. An investigation of the impacts of these four factors on image quality can help determine the most effective strategy in improving 4D-CBCT for IGRT. Methods: Fourteen 4D-CBCT patient projection datasets with various respiratory motion features were reconstructed with the following controllable factors: (i) respiratory signal (real-time position management, projection image intensity analysis, or fiducial marker tracking), (ii) binning method (phase, displacement, or equal-projection-density displacement binning), and (iii) reconstruction algorithm [Feldkamp–Davis–Kress (FDK), McKinnon–Bates (MKB), or adaptive-steepest-descent projection-onto-convex-sets (ASD-POCS)]. The image quality was quantified using signal-to-noise ratio (SNR), contrast-to-noise ratio, and edge-response width in order to assess noise/streaking and blur. The SNR values were also analyzed with respect to the maximum, mean, and root-mean-squared-error (RMSE) projection angular spacing to investigate how projection angular spacing affects image quality. Results: The choice of respiratory signals was found to have no significant impact on image quality. Displacement-based binning was found to be less prone to motion artifacts compared to phase binning in more than half of the cases, but was shown to suffer from large interbin image quality variation and large projection angular gaps. Both MKB and ASD-POCS resulted in noticeably improved image quality almost 100% of the time relative to FDK. In addition, SNR

  18. Thin Silicon Detector Technology for Use in Imaging Solar ENAs Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Top Level Objective: To enable capabilities for imaging and spectral measurements of energetic neutral hydrogen atoms (ENAs) produced with energies ∼1MeV/nuc in...

  19. High Spectral Resolution, High Cadence, Imaging X-ray Microcalorimeters for Solar Physics - Phase 2 Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcalorimeter x-ray instruments are non-dispersive, high spectral resolution, broad-band, high cadence imaging spectrometers. We have been developing these...

  20. US Participation in the Solar Orbiter Multi Element Telescope for Imaging and Spectroscopy (METIS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Multi Element Telescope for Imaging and Spectroscopy, METIS, investigation has been conceived to perform off-limb and near-Sun coronagraphy and is motivated by...

  1. Archaeological Geophysics in Field Courses and Flipped-Classrooms: Lessons Learned from the Marine and Geological Science Programs at North Carolina State University

    Science.gov (United States)

    Bohnenstiehl, D. R.; Wall, J.; Sprinkle, D. P., II

    2016-12-01

    The Department of Marine, Earth and Atmospheric Sciences at North Carolina State University routinely uses archaeological geophysics as an inquiry based teaching tool in our capstone Coastal Processes and Geologic Field Camps. Examples of past projects include a search for civil war artifacts within the moat surrounding historic Fort Macon, near Beaufort North Carolina, and investigations of ancient adobe pueblos in northern New Mexico. These types of studies, being of modest spatial scale, provide students with an opportunity to image the subsurface using multiple techniques and integrate the results into a geographic information system for analysis and interpretation. In the spring of 2016, our semester-long Applied Geophysics course was built around a project to identify unmarked graves at the Oberlin African-American cemetery Raleigh, North Carolina. The classroom experience was flipped with required readings, video lectures and weekly graded quizzes accessible online. Class meeting time was entirely spent collecting or processing data. To facilitate hands on learning, the class was taught with two sections having only ten students each. The methods used included GPR, EMI, Magnetics, and DC Resistivity. Students responded positively to the opportunity to tackle a real-world problem as part of the class; however, many where frustrated by the expectation that they master theoretical aspects of the course using the online content. Compared to a class taught with a traditional lecture format, students clearly gained more knowledge regarding field procedures; however, their performance on a comprehensive final suggests a poorer understand of many fundamental concepts.

  2. Basic methodology of tomographic imaging by filtered inverse projection at a turbo-pump. Project report; Methodische Grundlagen fuer die Tomographie durch gefilterte Rueckprojektion an einer Axialpumpe. Projektbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, D.

    2000-11-01

    A two-phase medium consisting of a fluid containing gas is transported in a turbo-pump via an impeller. The interaction between the gaseous phase and the impeller is to be examined by tomography with gamma rays. Reconstruction of the image of the object is to be made by way of filtered inverse projection. The methodology of using this principle in the given system (geometry and measuring conditions) is explained. (orig./CB) [German] Ein zweiphasiges, aus einer gashaltigen Fluessigkeit bestehendes Medium wird in einer Axialpumpe von einem propellerartigen Laufrad senkrecht zur Drehachse dieses Laufrades transportiert. Die Wechselwirkung zwischen der Gasphase und dem Laufrad soll unter Verwendung von Gamma-Strahlung mittels Tomographie untersucht werden. Dabei ist fuer die Rekonstruktion des Objektbildes das Prinzip der sogenannten gefilterten Rueckprojektion vorgesehen. Die methodischen Grundlagen fuer die Nutzung dieses Prinzips unter von vorgesehenen geometrischen und messtechnischen Bedingungen sind Gegenstand dieser Arbeit. (orig.)

  3. Virtual autopsy using imaging: bridging radiologic and forensic sciences. A review of the Virtopsy and similar projects

    International Nuclear Information System (INIS)

    Bolliger, Stephan A.; Thali, Michael J.; Ross, Steffen; Buck, Ursula; Naether, Silvio; Vock, Peter

    2008-01-01

    The transdisciplinary research project Virtopsy is dedicated to implementing modern imaging techniques into forensic medicine and pathology in order to augment current examination techniques or even to offer alternative methods. Our project relies on three pillars: three-dimensional (3D) surface scanning for the documentation of body surfaces, and both multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) to visualise the internal body. Three-dimensional surface scanning has delivered remarkable results in the past in the 3D documentation of patterned injuries and of objects of forensic interest as well as whole crime scenes. Imaging of the interior of corpses is performed using MSCT and/or MRI. MRI, in addition, is also well suited to the examination of surviving victims of assault, especially choking, and helps visualise internal injuries not seen at external examination of the victim. Apart from the accuracy and three-dimensionality that conventional documentations lack, these techniques allow for the re-examination of the corpse and the crime scene even decades later, after burial of the corpse and liberation of the crime scene. We believe that this virtual, non-invasive or minimally invasive approach will improve forensic medicine in the near future. (orig.)

  4. The Mammographic Head Demonstrator Developed in the Framework of the “IMI” Project:. First Imaging Tests Results

    Science.gov (United States)

    Bisogni, Maria Giuseppina

    2006-04-01

    In this paper we report on the performances and the first imaging test results of a digital mammographic demonstrator based on GaAs pixel detectors. The heart of this prototype is the X-ray detection unit, which is a GaAs pixel sensor read-out by the PCC/MEDIPIXI circuit. Since the active area of the sensor is 1 cm2, 18 detectors have been organized in two staggered rows of nine chips each. To cover the typical mammographic format (18 × 24 cm2) a linear scanning is performed by means of a stepper motor. The system is integrated in mammographic equipment comprehending the X-ray tube, the bias and data acquisition systems and the PC-based control system. The prototype has been developed in the framework of the integrated Mammographic Imaging (IMI) project, an industrial research activity aiming to develop innovative instrumentation for morphologic and functional imaging. The project has been supported by the Italian Ministry of Education, University and Research (MIUR) and by five Italian High Tech companies in collaboration with the universities of Ferrara, Roma “La Sapienza”, Pisa and the INFN.

  5. Examination of imaging detectors for combined radiography procedures in the ACCIS joint project. Automatic cargo container inspection system. Final report

    International Nuclear Information System (INIS)

    Dangendorf, Volker

    2014-01-01

    Currently used screening systems of air cargo are based on X-ray radiation from bremsstrahlung generators. Thus, different substances from light elements of approximately the same density are difficult to distinguish, e.g. the image contrast between explosives and drugs is low compared to harmless organic substances, such as plastic parts or foodstuffs, and requires extensive follow-up investigations. On the other hand, the image contrast is also low in the case of heavy elements with X-ray methods, e.g. Special Nuclear Materials (SNM) such as Pu and.U, which are also transported in a container of lead for camouflage and mixed with goods from other heavy metals, makes it very difficult. Within the framework of the ACCIS Collaborative Project, a new inspection system for airfreight based on neutron and gamma irradiation was researched. Within this framework, the PTB subproject covered the following tasks: 1. Research and development of laboratory prototypes of imaging radiation detectors; 2. Development of a measuring station for the evaluation of the screening method at the PTB accelerator system, 3. Cooperation in the development of a concept for a pulsed radiation source, in particular design and investigation of the beam-producing target. 4. Determination of the physical and dosimetric parameters relevant to radiation protection. Examination of the conditions of application, requirement of operational facility, end user contacts; 6. Coordination of the German partners, in particular organization of the project meetings of the German and Israeli partners. [de

  6. Airborne Geophysics and Remote Sensing Applied to Study Greenland Ice Dynamics

    Science.gov (United States)

    Csatho, Beata M.

    2003-01-01

    Overview of project: we combined and jointly analysed geophysical, remote sensing and glaciological data for investigating the temporal changes in ice flow and the role of geologic control on glacial drainage. The project included two different studies, the investigation of recent changes of the Kangerlussuaq glacier and the study of geologic control of ice flow in NW Greenland, around the Humboldt, Petermann and Ryder glaciers.

  7. Program report for FY 1980. Atmospheric and Geophysical Sciences Division of the Physics Department

    International Nuclear Information System (INIS)

    Knox, J.B.; Orphan, R.C.

    1981-02-01

    The FY 1980 research program conducted by the Atmospheric and Geophysical Sciences Division and supporting segments at Lawrence Livermore National Laboratory is reviewed briefly. The work is divided into five research themes: advanced modeling, regional modeling and assessments, CO 2 and climate research, stratospheric research, and special projects. Specific projects are described, and significant findings of the work are indicated. Unique numerical modeling capabilities in use and under development are described

  8. Brief overview of geophysical probing technology

    International Nuclear Information System (INIS)

    Ramirez, A.L.; Lytle, R.J.

    1982-01-01

    An evaluation of high-resolution geophysical techniques which can be used to characterize a nulcear waste disposal site is being conducted by the Lawrence Livermore National Laboratory (LLNL) at the request of the US Nuclear Regulatory Commisson (NRC). LLNL is involved in research work aimed at evaluating the current capabilities and limitations of geophysical methods used for site selection. This report provides a brief overview of the capabilities and limitations associated with this technology and explains how our work addresses some of the present limitations. We are examining both seismic and electromagnetic techniques to obtain high-resolution information. We are also assessing the usefulness of geotomography in mapping fracture zones remotely. Finally, we are collecting core samples from a site in an effort to assess the capability of correlating such geophysical data with parameters of interest such as fracture continuity, orientation, and fracture density

  9. Reduce blurring and distortion in a projection type virtual image display using integrated small optics

    Science.gov (United States)

    Hasegawa, Tatsuya; Yendo, Tomohiro

    2015-03-01

    Head Up Display (HUD) is being applied to automobile. HUD displays information as far virtual image on the windshield. Existing HUD usually displays planar information. If the image corresponding to scenery on the road like Augmented Reality (AR) is displayed on the HUD, driver can efficiently get the information. To actualize this, HUD covering large viewing field is needed. However existing HUD cannot cover large viewing field. Therefore we have proposed system consisting of projector and many small diameter convex lenses. However observed virtual image has blurring and distortion . In this paper, we propose two methods to reduce blurring and distortion of images. First, to reduce blurring of images, distance between each of screen and lens comprised in lens array is adjusted. We inferred from the more distant the lens from center of the array is more blurred that the cause of blurring is curvature of field of lens in the array. Second, to avoid distortion of images, each lens in the array is curved spherically. We inferred from the more distant the lens from center of the array is more distorted that the cause of distortion is incident angle of ray. We confirmed effectiveness of both methods.

  10. Geophysical experiments at Mariano Lake uranium orebody

    International Nuclear Information System (INIS)

    Thompson, D.T.

    1980-01-01

    Several geophysical experiments were performed over the Mariano Lake orebody before mining. Surface self-potential methods, surface-to-hole induced-polarization methods, and reflection-seismic methods were used. These geophysical techniques provided data which relate to the concep