WorldWideScience

Sample records for satellite study volume

  1. Satellite Power Systems (SPS) concept definition study. Volume 5: Special emphasis studies. [rectenna and solar power satellite design studies

    Science.gov (United States)

    Hanley, G. M.

    1980-01-01

    Satellite configurations based on the Satellite Power System baseline requirements were analyzed and a preferred concept selected. A satellite construction base was defined, precursor operations incident to establishment of orbital support facilities identified, and the satellite construction sequence and procedures developed. Rectenna construction requirement were also addressed. Mass flow to orbit requirements were revised and traffic models established based on construction of 60 instead of 120 satellites. Analyses were conducted to determine satellite control, resources, manufacturing, and propellant requirements. The impact of the laser beam used for space-to-Earth power transmission upon the intervening atmosphere was examined as well as the inverse effect. The significant space environments and their effects on spacecraft components were investigated to define the design and operational limits imposed by the environments on an orbit transfer vehicle. The results show that LEO altitude 300 nmi and transfer orbit duration 6 months are preferrable.

  2. Satellite power systems (SPS) concept definition study. Volume 7: SPS program plan and economic analysis, appendixes

    Science.gov (United States)

    Hanley, G.

    1978-01-01

    Three appendixes in support of Volume 7 are contained in this document. The three appendixes are: (1) Satellite Power System Work Breakdown Structure Dictionary; (2) SPS cost Estimating Relationships; and (3) Financial and Operational Concept. Other volumes of the final report that provide additional detail are: Executive Summary; SPS Systems Requirements; SPS Concept Evolution; SPS Point Design Definition; Transportation and Operations Analysis; and SPS Technology Requirements and Verification.

  3. Study in the Area of Satellite Meteorology. Volume 1. Mesoscale Weather Analysis and Prediction

    Science.gov (United States)

    1974-11-01

    and E. J. Wiegman , "Study of Time-Lapse Processing for Dynamic Hydrologie Conditions," Final Report, NASA Contract NAS5-21841...J. Wiegman , R. G. Hadfield, and W. E. Evans, "Electronic System for Utilization of Satellite Cloud Pictures, " Bull. Amer...Photographs," S~mp Research Paper 71, University of Chicago, Chicago, Ill., 25 pp. (1968). 21. S. M. Serebreny, E. J. Wiegman , R. G. Hadfield, and W. E

  4. Satellite Power Systems (SPS) concept definition study. Volume 4: SPS point design definition

    Science.gov (United States)

    Hanley, G.

    1978-01-01

    The satellite power systems point design concept is described. The concept definition includes satellite, ground and space systems, and their relationships. Emphasis is placed on the definition of the GaAlAs photovoltaic satellite system. The major subsystems of the satellite system including power conversion, power distribution and control, microwave, attitude control and stationkeeping, thermal control, structures, and information management and control are discussed.

  5. Satellite Power Systems (SPS) concept definition study. Volume 2, part 2: System engineering

    Science.gov (United States)

    Hanley, G. M.

    1980-09-01

    The latest technical and programmatic developments are considered as well as expansions of the Rockwell SPS cost model covering each phase of the program through the year 2030. Comparative cost/economic analyses cover elements of the satellite, construction system, space transportation vehicles and operations, and the ground receiving station. System plans to define time phased costs and planning requirements that support major milestones through the year 2000. A special analysis is included on natural resources required to build the SPS reference configuration. An appendix contains the SPS Work Breakdown Structure and dictionary along with detail cost data sheet on each system and main element of the program. Over 200 line items address DDT&E, theoretical first unit, investment cost per satellite, and operations charges for replacement capital and normal operations and maintenance costs.

  6. Satellite Power Systems (SPS) concept definition study. Volume 2, part 2: System engineering. [cost and programmatics

    Science.gov (United States)

    Hanley, G. M.

    1980-01-01

    The latest technical and programmatic developments are considered as well as expansions of the Rockwell SPS cost model covering each phase of the program through the year 2030. Comparative cost/economic analyses cover elements of the satellite, construction system, space transportation vehicles and operations, and the ground receiving station. System plans to define time phased costs and planning requirements that support major milestones through the year 2000. A special analysis is included on natural resources required to build the SPS reference configuration. An appendix contains the SPS Work Breakdown Structure and dictionary along with detail cost data sheet on each system and main element of the program. Over 200 line items address DDT&E, theoretical first unit, investment cost per satellite, and operations charges for replacement capital and normal operations and maintenance costs.

  7. Induction studies with satellite data

    DEFF Research Database (Denmark)

    Olsen, Nils

    1999-01-01

    analysis of the geomagnetic field is performed, and the Q-response, which is the transfer function between the internal (induced) and the external (inducing) expansion coefficients is determined for a specific frequency. In the second approach, known as the geomagnetic depth sounding method, the C....... This paper reviews and discusses the possibilities for induction studies using high-precision magnetic measurements from low-altitude satellites. The different methods and various transfer functions are presented, with special emphasis on the differences in analysing data from ground stations and from...... satellites. The results of several induction studies with scalar satellite data (from the POGO satellites) and with vector data (from the Magsat mission) demonstrate the ability to probe the Earth's conductivity from space. However, compared to the results obtained with ground data the satellite results...

  8. Computing and Visualizing Reachable Volumes for Maneuvering Satellites

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, M; de Vries, W H; Pertica, A J; Olivier, S S

    2011-09-11

    Detecting and predicting maneuvering satellites is an important problem for Space Situational Awareness. The spatial envelope of all possible locations within reach of such a maneuvering satellite is known as the Reachable Volume (RV). As soon as custody of a satellite is lost, calculating the RV and its subsequent time evolution is a critical component in the rapid recovery of the satellite. In this paper, we present a Monte Carlo approach to computing the RV for a given object. Essentially, our approach samples all possible trajectories by randomizing thrust-vectors, thrust magnitudes and time of burn. At any given instance, the distribution of the 'point-cloud' of the virtual particles defines the RV. For short orbital time-scales, the temporal evolution of the point-cloud can result in complex, multi-reentrant manifolds. Visualization plays an important role in gaining insight and understanding into this complex and evolving manifold. In the second part of this paper, we focus on how to effectively visualize the large number of virtual trajectories and the computed RV. We present a real-time out-of-core rendering technique for visualizing the large number of virtual trajectories. We also examine different techniques for visualizing the computed volume of probability density distribution, including volume slicing, convex hull and isosurfacing. We compare and contrast these techniques in terms of computational cost and visualization effectiveness, and describe the main implementation issues encountered during our development process. Finally, we will present some of the results from our end-to-end system for computing and visualizing RVs using examples of maneuvering satellites.

  9. Computing and Visualizing Reachable Volumes for Maneuvering Satellites

    Science.gov (United States)

    2011-09-01

    Computing and Visualizing Reachable Volumes for Maneuvering Satellites Ming Jiang, Willem H. de Vries, Alexander J. Pertica , Scot S. Olivier...Handbook. Elsevier, 2004. 6. M. Jiang, M. Andereck, A. J. Pertica , and S. S. Olivier. A Scalable Visualization System for Improving Space Situational...Jiang, J. Leek, J. L. Levatin, S. Nikolaev, A. J. Pertica , D. W. Phillion, H. K. Springer, and W. H. de Vries. High-Performance Computer Modeling of

  10. Tracking and data relay satellite system configuration and tradeoff study. Volume 4: TDRS system operation and control and telecommunications service system, part 1

    Science.gov (United States)

    1972-01-01

    Major study areas treated in this volume are: 1) operations and control and 2) the telecommunication service system. The TDRS orbit selection, orbital deployment, ground station visibility, sequence of events from launch to final orbit position, and TDRS control center functions required for stationkeeping, repositioning, attitude control, and antenna pointing are briefly treated as part of the operations and control section. The last topic of this section concerns the operations required for efficiently providing the TDRSS user telecommunication services. The discussion treats functions of the GSFC control and data processing facility, ground station, and TDRS control center. The second major portion of this volume deals with the Telecommunication Service System (TSS) which consists of the ground station, TDRS communication equipment and the user transceiver. A summary of the requirements and objectives for the telecommunication services and a brief summary of the TSS capabilities is followed by communication system analysis, signal design, and equipment design. Finally, descriptions of the three TSS elements are presented.

  11. Influence of skeletal muscle satellite cells implanted into infarcted myocardium on remnant myocyte volumes

    Institute of Scientific and Technical Information of China (English)

    钟竑; 朱洪生; 卫洪超; 张臻

    2003-01-01

    Objective To study the effects of skeletal muscle satellite cells implanted into infarcted myocardium on the volume of remnant myocytes.Methods Thirty-six adult mongrel canines were divided randomly into implantation group and control group. In the implantation group, skeletal muscle satellite cells taken from the gluteus maximus muscles of the dogs were cultured, proliferated and labeled with 4', 6-diamidino-2-phenylindone (DAPI) in vitro. In both groups, a model of acute myocardial infarction was established in every dog. In the implantation group, each dog was injected with M199 solution containing autologous skeletal muscle satellite cells. The dogs in the control group received M199 solution without skeletal muscle satellite cells. The dogs of both groups were killed 2, 4 and 8 weeks after implantation (six dogs in a separate group each time). Both infarcted myocardium and normal myocytes distal from the infracted regions isolated were observed under optical and fluorescent microscope. Their volumes were determined using a confocal microscopy image analysis system and analyzed using SAS. A P<0.05 was considered significant.Results A portion of the implanted cells differentiated into muscle fiber with striations and were connected with intercalated discs. Cross-sectional area and cell volume were increased in normal myocardium. Hypertrophy of remnant myocytes in the infarcted site after skeletal muscle cell implantation was much more evident than in the control group. Cross-sectional area, cell area and cell volume differed significantly from those of the control group (P< 0.05). Hypertrophy of the cells occurred predominantly in terms of width and thickness, whereas cell length remained unchanged. Conclusion Skeletal muscle satellite cells implanted into infarct myocardium, could induce the hypertrophy of remnant myocyte cells in the infarcted site and could also aid in the recovery of the contractile force of the infarcted myocardium.

  12. SEASAT economic assessment. Volume 9: Ports and harbors case study and generalization. [economic benefits of SEASAT satellites to harbors and shipping industries through improved weather forecasting

    Science.gov (United States)

    1975-01-01

    This case study and generalization quantify benefits made possible through improved weather forecasting resulting from the integration of SEASAT data into local weather forecasts. The major source of avoidable economic losses to shipping from inadequate weather forecasting data is shown to be dependent on local precipitation forecasting. The ports of Philadelphia and Boston were selected for study.

  13. SEASAT economic assessment. Volume 5: Coastal zones case study and generalization. [economic benefits of weather forecasting by SEASAT satellites to the coastal plains of the United States

    Science.gov (United States)

    1975-01-01

    The economic losses sustained in the U.S. coastal zones were studied for the purpose of quantitatively establishing economic benefits as a consequence of improving the predictive quality of destructive phenomena in U.S. coastal zones. Improved prediction of hurricane landfall and improved experimental knowledge of hurricane seeding are discussed.

  14. Estimate Landslide Volume with Genetic Algorithms and Image Similarity Method from Single Satellite Image

    Science.gov (United States)

    Yu, Ting-To

    2013-04-01

    It is important to acquire the volume of landslide in short period of time. For hazard mitigation and also emergency response purpose, the traditional method takes much longer time than expected. Due to the weather limit, traffic accessibility and many regulations of law, it take months to handle these process before the actual carry out of filed work. Remote sensing imagery can get the data as long as the visibility allowed, which happened only few day after the event. While traditional photometry requires a stereo pairs images to produce the post event DEM for calculating the change of volume. Usually have to wait weeks or even months for gathering such data, LiDAR or ground GPS measurement might take even longer period of time with much higher cost. In this study we use one post event satellite image and pre-event DTM to compare the similarity between these by alter the DTM with genetic algorithms. The outcome of smartest guess from GAs shall remove or add exact values of height at each location, which been converted into shadow relief viewgraph to compare with satellite image. Once the similarity threshold been make then the guessing work stop. It takes only few hours to finish the entire task, the computed accuracy is around 70% by comparing to the high resolution LiDAR survey at a landslide, southern Taiwan. With extra GCPs, the estimate accuracy can improve to 85% and also within few hours after the receiving of satellite image. Data of this demonstration case is a 5 m DTM at 2005, 2M resolution FormoSat optical image at 2009 and 5M LiDAR at 2010. The GAs and image similarity code is developed on Matlab at windows PC.

  15. Navigation Performance of Global Navigation Satellite Systems in the Space Service Volume

    Science.gov (United States)

    Force, Dale A.

    2013-01-01

    GPS has been used for spacecraft navigation for many years center dot In support of this, the US has committed that future GPS satellites will continue to provide signals in the Space Service Volume center dot NASA is working with international agencies to obtain similar commitments from other providers center dot In support of this effort, I simulated multi-constellation navigation in the Space Service Volume In this presentation, I extend the work to examine the navigational benefits and drawbacks of the new constellations center dot A major benefit is the reduced geometric dilution of precision (GDOP). I show that there is a substantial reduction in GDOP by using all of the GNSS constellations center dot The increased number of GNSS satellites broadcasting does produce mutual interference, raising the noise floor. A near/far signal problem can also occur where a nearby satellite drowns out satellites that are far away. - In these simulations, no major effect was observed Typically, the use of multi-constellation GNSS navigation improves GDOP by a factor of two or more over GPS alone center dot In addition, at the higher altitudes, four satellite solutions can be obtained much more often center dot This show the value of having commitments to provide signals in the Space Service Volume Besides a commitment to provide a minimum signal in the Space Service Volume, detailed signal gain information is useful for mission planning center dot Knowledge of group and phase delay over the pattern would also reduce the navigational uncertainty

  16. Ravens satellite mission concept study

    CERN Document Server

    Donovan, Eric F

    2011-01-01

    The concept for Ravens satellite mission was proposed in response to a CSA AO for potential Canadian mission contributions to the International Living With a Star (ILWS) program. Ravens was conceived of to fill an important gap in the ILWS program: global imaging. Ravens will build on the heritage of world-class global imaging carried out in Canada. It would do much more than provide global observations to complete the system level capabilities of ILWS. Ravens would be comprised of two satellites on elliptical polar orbits, relatively phased on those orbits to provide the first-ever continuous (ie., 24 hours per day 7 days per week) global imaging of the northern hemisphere auroral and polar cap regions. This would provide the first-ever unbroken sequences of global images of the auroral response during long duration geomagnetic processes like storms and steady magnetospheric convection events. Ravens could track the spatio-temporal evolution of the global electron and proton auroral distribution, and would o...

  17. Satellite Contributions to Global Change Studies

    Science.gov (United States)

    Parkinson, Claire L.

    2009-01-01

    sophisticated climate models, in situ process studies, and data sets that extend back well before the introduction of satellite technology. Nonetheless, the repetitive, global view provided by satellites is contributing in a major way to our improved recognition of how the Earth im changing, a recognition that is none too soon in view of the magnitude of the impacts that humans can now have.

  18. Preliminary environmental assessment for the Satellite Power System (SPS). Revision 1. Volume 2. Detailed assessment

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    The Department of Energy (DOE) is considering several options for generating electrical power to meet future energy needs. The satellite power system (SPS), one of these options, would collect solar energy through a system of satellites in space and transfer this energy to earth. A reference system has been described that would convert the energy to microwaves and transmit the microwave energy via directive antennas to large receiving/rectifying antennas (rectennas) located on the earth. At the rectennas, the microwave energy would be converted into electricity. The potential environmental impacts of constructing and operating the satellite power system are being assessed as a part of the Department of Energy's SPS Concept Development and Evaluation Program. This report is Revision I of the Preliminary Environmental Assessment for the Satellite Power System published in October 1978. It refines and extends the 1978 assessment and provides a basis for a 1980 revision that will guide and support DOE recommendations regarding future SPS development. This is Volume 2 of two volumes. It contains the technical detail suitable for peer review and integrates information appearing in documents referenced herein. The key environmental issues associated with the SPS concern human health and safety, ecosystems, climate, and electromagnetic systems interactions. In order to address these issues in an organized manner, five tasks are reported: (I) microwave-radiation health and ecological effects; (II) nonmicrowave health and ecological effectss; (III) atmospheric effects; (IV) effects on communication systems due to ionospheric disturbance; and (V) electromagnetic compatibility. (WHK)

  19. Globally Gridded Satellite observations for climate studies

    Science.gov (United States)

    Knapp, K.R.; Ansari, S.; Bain, C.L.; Bourassa, M.A.; Dickinson, M.J.; Funk, C.; Helms, C.N.; Hennon, C.C.; Holmes, C.D.; Huffman, G.J.; Kossin, J.P.; Lee, H.-T.; Loew, A.; Magnusdottir, G.

    2011-01-01

    Geostationary satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite the long period of record, use of these data in climate studies has been limited for numerous reasons, among them that no central archive of geostationary data for all international satellites exists, full temporal and spatial resolution data are voluminous, and diverse calibration and navigation formats encumber the uniform processing needed for multisatellite climate studies. The International Satellite Cloud Climatology Project (ISCCP) set the stage for overcoming these issues by archiving a subset of the full-resolution geostationary data at ~10-km resolution at 3-hourly intervals since 1983. Recent efforts at NOAA's National Climatic Data Center to provide convenient access to these data include remapping the data to a standard map projection, recalibrating the data to optimize temporal homogeneity, extending the record of observations back to 1980, and reformatting the data for broad public distribution. The Gridded Satellite (GridSat) dataset includes observations from the visible, infrared window, and infrared water vapor channels. Data are stored in Network Common Data Format (netCDF) using standards that permit a wide variety of tools and libraries to process the data quickly and easily. A novel data layering approach, together with appropriate satellite and file metadata, allows users to access GridSat data at varying levels of complexity based on their needs. The result is a climate data record already in use by the meteorological community. Examples include reanalysis of tropical cyclones, studies of global precipitation, and detection and tracking of the intertropical convergence zone.

  20. Satellite animal tracking feasibility studies

    Science.gov (United States)

    Buechner, H. K.

    1975-01-01

    A study was initiated in Tsavo National Park to determine movements and home ranges of individual elephants and their relations to overall distribution patterns and environmental factors such as rainfall. Methods used were radio tracking and observations of visually identifiable individuals. Aerial counts provided data on overall distribution. Two bulls and two cows were radio-tagged in Tsavo West and two bulls and four cows in Tsavo East, providing home range and movement data. The movements of individuals were useful in interpreting relatively major shifts in elephant distribution. Results point to the following preliminary conclusions: (1) elephants in the Tsavo area undertook long distance movements in fairly direct response to localized rainfall; (2) a subdivision of the overall population into locally distinct units may exist during the dry season but did not occur after significant rainfall; and (3) food appears to be the primary factor governing movements and distribution of elephants in the area.

  1. Induction studies with satellite data

    DEFF Research Database (Denmark)

    Olsen, Nils

    1999-01-01

    -response, which is the transfer function between the magnetic vertical component and the horizontal derivative of the horizontal components, is determined. If one of these transfer functions is known for several frequencies, models of the electrical conductivity in the Earth's interior can be constructed...... for observations lasting several years, which helps to reduce the statistical error of the estimated response functions. Two methods are used to study the electrical conductivity of the Earth's mantle in the period range from hours to months. In the first, known as the potential method, a spherical harmonic...... analysis of the geomagnetic field is performed, and the Q-response, which is the transfer function between the internal (induced) and the external (inducing) expansion coefficients is determined for a specific frequency. In the second approach, known as the geomagnetic depth sounding method, the C...

  2. A preliminary study on dead geostationary satellite removal

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The collision between satellites IRIDIUM 33 and COSMOS 2251 indicated that the clash of two on-orbit satellites was becoming an inevitable reality. Our calculation with the two-line orbit element by NORAD showed that some two geostationary satellites had approached very close in July 2009. Therefore, more attention should be given to avoid such collisions. This paper analyzes the orbital long-term variation of a dead satellite drifting in the geostationary orbit. Also, the negative effects posed by dead satellites upon the on-orbit operational geostationary satellites are studied. Then the paper proposes a novel idea to launch a satellite sweeper whose purpose is to collect the on-orbit dead satellites and help them de-orbit to a "graveyard". The satellite sweeper consists of a parent satellite and a child satellite. The child satellite collects a dead satellite and transfers it to a higher orbit. The parent satellite stationed in the geostationary orbit is in charge of refueling the child satellite. The strategy of maneuver and rendezvous is presented and a series of formulas are derived. The analysis results show that our method to clean the geostationary orbital zone is practical and fuel-saving. With the help of just a few satellite sweepers, we can gain a clean environment of geostationary orbit environment again.

  3. The NOAA Satellite Observing System Architecture Study

    Science.gov (United States)

    Volz, Stephen; Maier, Mark; Di Pietro, David

    2016-01-01

    NOAA is beginning a study, the NOAA Satellite Observing System Architecture (NSOSA) study, to plan for the future operational environmental satellite system that will follow GOES and JPSS, beginning about 2030. This is an opportunity to design a modern architecture with no pre-conceived notions regarding instruments, platforms, orbits, etc. The NSOSA study will develop and evaluate architecture alternatives to include partner and commercial alternatives that are likely to become available. The objectives will include both functional needs and strategic characteristics (e.g., flexibility, responsiveness, sustainability). Part of this study is the Space Platform Requirements Working Group (SPRWG), which is being commissioned by NESDIS. The SPRWG is charged to assess new or existing user needs and to provide relative priorities for observational needs in the context of the future architecture. SPRWG results will serve as input to the process for new foundational (Level 0 and Level 1) requirements for the next generation of NOAA satellites that follow the GOES-R, JPSS, DSCOVR, Jason-3, and COSMIC-2 missions.

  4. Building high-performance system for processing a daily large volume of Chinese satellites imagery

    Science.gov (United States)

    Deng, Huawu; Huang, Shicun; Wang, Qi; Pan, Zhiqiang; Xin, Yubin

    2014-10-01

    The number of Earth observation satellites from China increases dramatically recently and those satellites are acquiring a large volume of imagery daily. As the main portal of image processing and distribution from those Chinese satellites, the China Centre for Resources Satellite Data and Application (CRESDA) has been working with PCI Geomatics during the last three years to solve two issues in this regard: processing the large volume of data (about 1,500 scenes or 1 TB per day) in a timely manner and generating geometrically accurate orthorectified products. After three-year research and development, a high performance system has been built and successfully delivered. The high performance system has a service oriented architecture and can be deployed to a cluster of computers that may be configured with high end computing power. The high performance is gained through, first, making image processing algorithms into parallel computing by using high performance graphic processing unit (GPU) cards and multiple cores from multiple CPUs, and, second, distributing processing tasks to a cluster of computing nodes. While achieving up to thirty (and even more) times faster in performance compared with the traditional practice, a particular methodology was developed to improve the geometric accuracy of images acquired from Chinese satellites (including HJ-1 A/B, ZY-1-02C, ZY-3, GF-1, etc.). The methodology consists of fully automatic collection of dense ground control points (GCP) from various resources and then application of those points to improve the photogrammetric model of the images. The delivered system is up running at CRESDA for pre-operational production and has been and is generating good return on investment by eliminating a great amount of manual labor and increasing more than ten times of data throughput daily with fewer operators. Future work, such as development of more performance-optimized algorithms, robust image matching methods and application

  5. Near threshold studies of photoelectron satellites

    Energy Technology Data Exchange (ETDEWEB)

    Heimann, P.A.

    1986-11-01

    Photoelectron spectroscopy and synchrotron radiation have been used to study correlation effects in the rare gases: He, Ne, Ar, Kr, and Xe. Two kinds of time-of-flight electron analyzers were employed to examine photoionization very close to threshold and at higher kinetic energies. Partial cross sections and angular distributions have been measured for a number of photoelectron satellites. The shake-off probability has been determined at some inner-shell resonances. 121 refs., 28 figs., 13 tabs.

  6. Methods of Celestial Mechanics Volume II: Application to Planetary System, Geodynamics and Satellite Geodesy

    CERN Document Server

    Beutler, Gerhard

    2005-01-01

    G. Beutler's Methods of Celestial Mechanics is a coherent textbook for students as well as an excellent reference for practitioners. Volume II is devoted to the applications and to the presentation of the program system CelestialMechanics. Three major areas of applications are covered: (1) Orbital and rotational motion of extended celestial bodies. The properties of the Earth-Moon system are developed from the simplest case (rigid bodies) to more general cases, including the rotation of an elastic Earth, the rotation of an Earth partly covered by oceans and surrounded by an atmosphere, and the rotation of an Earth composed of a liquid core and a rigid shell (Poincaré model). (2) Artificial Earth Satellites. The oblateness perturbation acting on a satellite and the exploitation of its properties in practice is discussed using simulation methods (CelestialMechanics) and (simplified) first order perturbation methods. The perturbations due to the higher-order terms of the Earth's gravitational potential and reso...

  7. Design of volume hologram filters for suppression of daytime sky brightness in artificial satellite detection.

    Science.gov (United States)

    Gao, Hanhong; Watson, Jonathan M; Stuart, Joseph Scott; Barbastathis, George

    2013-03-11

    We present a design methodology for volume hologram filters (VHFs) with telephoto objectives to improve contrast of solar-illuminated artificial satellites observed with a ground-based optical telescope and camera system operating in daytime. VHFs provide the ability to selectively suppress incoming light based on the range to the source, and are used to suppress the daylight background noise since signal (satellite) and noise (daylight scatterers) are located at different altitudes. We derive the overall signal-to-noise ratio (SNR) enhancement as the system metric, and balance main design parameters over two key performance considerations--daylight attenuation and spectral bandwidth--to optimize the functioning of VHFs. Overall SNR enhancement of 7.5 has been achieved. Usage of multi-pixel cameras can potentially further refine this system.

  8. Multidisciplinary studies of the social, economic and political impact resulting from recent advances in satellite meteorology. Volume 6: Executive summary. [technological forecasting spacecraft control/attitude (inclination) -classical mechanics

    Science.gov (United States)

    1975-01-01

    An assessment of the technological impact of modern satellite weather forecasting for the United States is presented. Topics discussed are: (1) television broadcasting of weather; (2) agriculture (crop production); (3) water resources; (4) urban development; (5) recreation; and (6) transportation.

  9. Reusable Reentry Satellite (RRS) system design study

    Science.gov (United States)

    1991-01-01

    The Reusable Reentry Satellite (RRS) is intended to provide investigators in several biological disciplines with a relatively inexpensive method to access space for up to 60 days with eventual recovery on Earth. The RRS will permit totally intact, relatively soft, recovery of the vehicle, system refurbishment, and reflight with new and varied payloads. The RRS is to be capable of three reflights per year over a 10-year program lifetime. The RRS vehicle will have a large and readily accessible volume near the vehicle center of gravity for the Payload Module (PM) containing the experiment hardware. The vehicle is configured to permit the experimenter late access to the PM prior to launch and rapid access following recovery. The RRS will operate in one of two modes: (1) as a free-flying spacecraft in orbit, and will be allowed to drift in attitude to provide an acceleration environment of less than 10(exp -5) g. the acceleration environment during orbital trim maneuvers will be less than 10(exp -3) g; and (2) as an artificial gravity system which spins at controlled rates to provide an artificial gravity of up to 1.5 Earth g. The RRS system will be designed to be rugged, easily maintained, and economically refurbishable for the next flight. Some systems may be designed to be replaced rather than refurbished, if cost effective and capable of meeting the specified turnaround time. The minimum time between recovery and reflight will be approximately 60 days. The PMs will be designed to be relatively autonomous, with experiments that require few commands and limited telemetry. Mass data storage will be accommodated in the PM. The hardware development and implementation phase is currently expected to start in 1991 with a first launch in late 1993.

  10. Review and Development on the Studies of Chinese Meteorological Satellite and Satellite Meteorology

    Institute of Scientific and Technical Information of China (English)

    FANG Zongyi; XU Jianmin; ZHAO Fengsheng

    2006-01-01

    Meteorological satellite and satellite meteorology are the fastest developing new branches in the atmospheric sciences. Today the meteorological satellite has become a key element in the global atmospheric sounding system while the satellite meteorology is covering the main components of earth's system science.This article describes the major achievements that China has made in these fields in the past 30 years.The following contents are involved: (1) History and present status of China's meteorological satellites. It covers the development, launch, operation, technical parameters of China's polar and geostationary meteorological satellites. (2) Major achievements on remote sensing principle and method. It describes the retrieval of atmospheric temperature and humidity profiles, cloud character retrieval, aerosol character retrieval, precipitation retrieval as well as the generation of cloud wind. (3) Achievement on the studies of meteorological satellite data application. This part covers the applications of meteorological satellite data to weather analysis and forecast, numerical forecast, climate monitoring, and prediction of short-term climate change. Besides, the new results on data assimilation, climate monitoring, and forecast are also included.

  11. Spacecraft (Mobile Satellite) configuration design study

    Science.gov (United States)

    1985-01-01

    The relative costs to procure and operate a two-satellite mobile satellite system designed to operate either in the UHF band of the L Band, and with several antenna diameter options in each frequency band was investigated. As configured, the size of the spacecraft is limited to the current RCA Series 4000 Geosynchronous Communications Spacecraft bus, which spans the range from 4000 to 5800 pounds in the transfer orbit. The Series 4000 bus forms the basis around which the Mobile Satellite transponder and associated antennas were appended. Although the resultant configuration has little outward resemblance to the present Series 4000 microwave communications spacecraft, the structure, attitude control, thermal, power, and command and control subsystems of the Series 4000 spacecraft are all adapted to support the Mobile Satellite mission.

  12. TDRSS/user satellite timing study

    Science.gov (United States)

    Mcgregor, D.; Douglas, F.; Kaul, R.

    1976-01-01

    A timing analysis for data readout through the Tracking and Data Relay Satellite System (TDRSS) was presented. Various time tagging approaches were considered and the resulting accuracies delineated. The TDRSS was also defined and described in detail.

  13. A satellite study of dayside auroral conjugacy

    Directory of Open Access Journals (Sweden)

    H. B. Vo

    Full Text Available A study of dayside auroral conjugacy has been done using the cleft/boundary layer auroral particle boundaries observed by the DMSP-F7 satellite in the southern hemisphere and the global UV auroral images taken by the Viking spacecraft in the northern hemisphere. The 22 events have been studied on the basis of an internal IGRF 1985 magnetic field; it is shown that there is a displacement of up to 4° in latitude from the conjugate points with the northern aurora appearing to be located poleward of the conjugate point. No local time dependence of the north-south auroral location difference was seen. The use of a more realistic magnetic field model for tracing field lines which incorporates the dipole tilt angle and Kp index, the Tsyganenko 1987 long model plus the IGRF 1985 internal magnetic field model, appears to organize the data better. Although with this external plus internal model some tracings did not close in the opposite hemisphere, 70% of those that did indicated satisfactory conjugacy. The study shows that the degree of auroral conjugacy is dependent upon the accuracy of the magnetic field model used to trace to the conjugate point, especially in the dayside region where the field lines can either go to the dayside magnetopause near the subsolar point or sweep all the way back to the flanks of the magnetotail. Also the discrepancy in the latitude of northern and southern aurora can be partially explained by the displacement of the neutral sheet (source region of the aurora by the dipole tilt effect.

  14. Do Red Edge and Texture Attributes from High-Resolution Satellite Data Improve Wood Volume Estimation in a Semi-Arid Mountainous Region?

    DEFF Research Database (Denmark)

    Schumacher, Paul; Mislimshoeva, Bunafsha; Brenning, Alexander;

    2016-01-01

    Remote sensing-based woody biomass quantification in sparsely-vegetated areas is often limited when using only common broadband vegetation indices as input data for correlation with ground-based measured biomass information. Red edge indices and texture attributes are often suggested as a means...... to overcome this issue. However, clear recommendations on the suitability of specific proxies to provide accurate biomass information in semi-arid to arid environments are still lacking. This study contributes to the understanding of using multispectral high-resolution satellite data (RapidEye), specifically...... red edge and texture attributes, to estimate wood volume in semi-arid ecosystems characterized by scarce vegetation. LASSO (Least Absolute Shrinkage and Selection Operator) and random forest were used as predictive models relating in situ-measured aboveground standing wood volume to satellite data...

  15. Volume magnetization for system-level testing of magnetic materials within small satellites

    Science.gov (United States)

    Gerhardt, David T.; Palo, Scott E.

    2016-10-01

    Passive Magnetic Attitude Control (PMAC) is a popular among small satellites due to its low resource cost and simplicity of installation. However, predicting the performance of these systems can be a challenge, chiefly due to the difficulty of measurement and simulation of hysteresis materials. We present a low-cost method of magnetic measurement allowing for characterization of both hard and soft magnetic materials. A Helmholtz cage uniformly magnetizes a 30 cm×30 cm×30 cm test volume. The addition of a thin sense coil allows this system to characterize individual hysteresis rod performance when in close proximity to other hard and/or soft magnetic materials. This test setup is applied to hard and soft magnetic materials used aboard the Colorado Student Space Weather Experiment (CSSWE), a 3U CubeSat for space weather investigation which used a PMAC system. The measured hard magnet dipole of 0.80±0.017 A m2 is in good agreement with the dynamics-based satellite dipole moment fits. Five hysteresis rods from the same set as the CSSWE flight rods are tested; significant differences in dampening abilities are found. In addition, a limitation of the widely-used Flatley model is described. The interaction of two hysteresis rods in a variety of relative geometries are tested; perpendicular rods are found to have no significant interaction while parallel rods could have their dampening ability reduced by half, depending on the rod separation distance. Finally, the performance of the hysteresis rods are measured in their flight configuration, with hard and soft magnetic material dispersed as it is on CSSWE itself. For the CSSWE PMAC system design, interactions between rods have a greater affect than the magnetic flux density offset due to the onboard bar magnet.

  16. A comparative study of satellite and ground-based phenology.

    Science.gov (United States)

    Studer, S; Stöckli, R; Appenzeller, C; Vidale, P L

    2007-05-01

    Long time series of ground-based plant phenology, as well as more than two decades of satellite-derived phenological metrics, are currently available to assess the impacts of climate variability and trends on terrestrial vegetation. Traditional plant phenology provides very accurate information on individual plant species, but with limited spatial coverage. Satellite phenology allows monitoring of terrestrial vegetation on a global scale and provides an integrative view at the landscape level. Linking the strengths of both methodologies has high potential value for climate impact studies. We compared a multispecies index from ground-observed spring phases with two types (maximum slope and threshold approach) of satellite-derived start-of-season (SOS) metrics. We focus on Switzerland from 1982 to 2001 and show that temporal and spatial variability of the multispecies index correspond well with the satellite-derived metrics. All phenological metrics correlate with temperature anomalies as expected. The slope approach proved to deviate strongly from the temporal development of the ground observations as well as from the threshold-defined SOS satellite measure. The slope spring indicator is considered to indicate a different stage in vegetation development and is therefore less suited as a SOS parameter for comparative studies in relation to ground-observed phenology. Satellite-derived metrics are, however, very susceptible to snow cover, and it is suggested that this snow cover should be better accounted for by the use of newer satellite sensors.

  17. Using Satellite Imagery to Study Landslides

    Science.gov (United States)

    Reif, S. L.; Bluth, G. J.; Rose, W. I.; Matias, O.; Wolf, R.

    2003-04-01

    Much of the world's population currently lives under the threat of volcanic hazards in the secondary form of debris movements such as landslides and lahars. Remote sensing is becoming a useful tool for hazard studies, yet many hazard-prone areas do not utilize this important resource. In this project, we intend to use common remote sensing techniques to study characteristics of landslides and lahars in order to predict hazard zones. Fuego Volcano in Guatemala is a steep sided volcano with a history of large eruptive events, including the well-studied 1974 eruption, that have extruded a large amount of material onto the upper reaches of the Fuego watersheds. Eruption processes have been a primary focus of studies; however, remobilization during the rainy season of the erupted material is hazardous to the local population and agriculture (Vallance et al. 2001, USGS Open-File Report 01-431). A study of the way material moves down Fuego and to the extent that it moves is needed to help properly mitigate the potential hazards. We propose an in-depth remote sensing survey to map the hazard-prone areas. The study will consist of processing 20 years (15 cloud-free images) of Landsat TM and ETM+ data to look at changes in landforms and vegetation. Vegetation indices will be calculated to locate areas devoid of vegetation and a masking process will be used to measure the area of these zones. These area changes will be related to field measurements to create GIS layers denoting geometry changes in the channels around Fuego. These changes will be loaded into a GIS, along with regional climate data, DEMs, hydrologic data, infrastructure, and information about the known volcanic activity recorded in the area by the local volcanologists. Modeling of lahars using LAHARZ and climate data will also be done to determine an estimate of the amount of material moved and to what distances it can be transported. A field survey undertaken in January 2003 acquired GPS ground truth data of

  18. Low-Cost Satellite Infrared Imager Study

    Science.gov (United States)

    2007-11-02

    2,297.00 10 MATLAB , Simulink , Symbolic Math Toolbox (2 ea @ £894) £1,788.00 11 MATLAB Image Processing Toolbox (2 ea at £192) £384.00 12 MATLAB ...Figure 1: MWIR and TIR satellite imagery. On the left is a BIRD image of forest fires on the Portuguese/ Spanish border3 and the image on right is...space-borne MWIR and TIR imagers, instrument engineers are continually evaluating advances in the miniaturization of detector technology. One

  19. Evaluation of spacecraft technology programs (effects on communication satellite business ventures), volume 2

    Science.gov (United States)

    Greenburg, J. S.; Kaplan, M.; Fishman, J.; Hopkins, C.

    1985-01-01

    The computational procedures used in the evaluation of spacecraft technology programs that impact upon commercial communication satellite operations are discussed. Computer programs and data bases are described.

  20. Optimizing Crystal Volume for Neutron Diffraction Studies

    Science.gov (United States)

    Snell, E. H.

    2003-01-01

    For structural studies with neutron diffraction more intense neutron sources, improved sensitivity detector and larger volume crystals are all means by which the science is being advanced to enable studies on a wider range of samples. We have chosen a simplistic approach using a well understood crystallization method, with minimal amounts of sample and using design of experiment techniques to maximize the crystal volume all for minimum effort. Examples of the application are given.

  1. Preliminary environmental assessment for the satellite power system (SPS). Revision 1. Volume 1. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    1980-01-01

    A preliminary assessment of the environmental impacts of the proposed satellite power system (SPS) is summarized here. In this system, satellites would collect solar energy in space, convert it to microwaves, and transmit the microwaves to receiving antennas (rectennas) on earth. At the rectennas, the microwaves would be converted to electricity. The assessment considers microwave and nonmicrowave effects on the terrestrial environment and human health, atmospheric effects, and disruption of communications and other electromagnetic systems.

  2. Bifilar analysis study, volume 1

    Science.gov (United States)

    Miao, W.; Mouzakis, T.

    1980-01-01

    A coupled rotor/bifilar/airframe analysis was developed and utilized to study the dynamic characteristics of the centrifugally tuned, rotor-hub-mounted, bifilar vibration absorber. The analysis contains the major components that impact the bifilar absorber performance, namely, an elastic rotor with hover aerodynamics, a flexible fuselage, and nonlinear individual degrees of freedom for each bifilar mass. Airspeed, rotor speed, bifilar mass and tuning variations are considered. The performance of the bifilar absorber is shown to be a function of its basic parameters: dynamic mass, damping and tuning, as well as the impedance of the rotor hub. The effect of the dissimilar responses of the individual bifilar masses which are caused by tolerance induced mass, damping and tuning variations is also examined.

  3. Satellite-aided mobile radio concepts study: Concept definition of a satellite-aided mobile and personal radio communication system

    Science.gov (United States)

    Anderson, R. E.

    1979-01-01

    The satellite system requires the use of a large satellite antenna and spacecraft array power of about 12 kW or more depending on the operating frequency. Technology developments needed include large offset reflector multibeam antennas, satellite electrical power sybsystems providing greater than 12 kW of power, signal switching hardware, and linearized efficient solid state amplifiers for the satellite-aided mobile band. Presently there is no frequency assignment for this service, and it is recommended that an allocation be pursued. The satellite system appears to be within reasonable extrapolation of the state of the art. It is further recommended that the satellite-aided system spacecraft definition studies and supporting technology development be initiated.

  4. Study on relative orbital configuration in satellite formation flying

    Institute of Scientific and Technical Information of China (English)

    Junfeng Li; Xin Meng; Yunfeng Gao; Xiang Li

    2005-01-01

    In this paper, the relative orbital configurations of satellites in formation flying with non-perturbation and J2 perturbation are studied, and an orbital elements method is proposed to obtain the relative orbital configurations of satellites in formation. Firstly, under the condition of nonperturbation, we obtain many shapes of relative orbital configurations when the semi-major axes of satellites are equal.These shapes can be lines, ellipses or distorted closed curves.Secondly, on the basis of the analysis of J2 effect on relative orbital configurations, we find out that J2 effect can induce two kinds of changes of relative orbital configurations. They are distortion and drifting, respectively. In addition, when J2perturbation is concerned, we also find that the semi-major axes of the leading and following satellites should not be the same exactly in order to decrease the J2 effect. The relationship of relative orbital elements and J2 effect is obtained through simulations. Finally, the minimum relation perturbation conditions are established in order to reduce the influence of the J2 effect. The results show that the minimum relation perturbation conditions can reduce the J2 effect significantly when the orbital element differences are small enough, and they can become rules for the design of satellite formation flying.

  5. Evaluation of spacecraft technology programs (effects on communication satellite business ventures), volume 1

    Science.gov (United States)

    Greenburg, J. S.; Gaelick, C.; Kaplan, M.; Fishman, J.; Hopkins, C.

    1985-01-01

    Commercial organizations as well as government agencies invest in spacecraft (S/C) technology programs that are aimed at increasing the performance of communications satellites. The value of these programs must be measured in terms of their impacts on the financial performane of the business ventures that may ultimately utilize the communications satellites. An economic evaluation and planning capability was developed and used to assess the impact of NASA on-orbit propulsion and space power programs on typical fixed satellite service (FSS) and direct broadcast service (DBS) communications satellite business ventures. Typical FSS and DBS spin and three-axis stabilized spacecraft were configured in the absence of NASA technology programs. These spacecraft were reconfigured taking into account the anticipated results of NASA specified on-orbit propulsion and space power programs. In general, the NASA technology programs resulted in spacecraft with increased capability. The developed methodology for assessing the value of spacecraft technology programs in terms of their impact on the financial performance of communication satellite business ventures is described. Results of the assessment of NASA specified on-orbit propulsion and space power technology programs are presented for typical FSS and DBS business ventures.

  6. Jail Removal Cost Study. Volume 2.

    Science.gov (United States)

    Illinois Univ., Champaign. Community Research Center.

    This second volume of the jail removal cost study provides a detailed report of the study findings which examine the costs, experiences, and ramifications of removing children from adult jails and lockups. The foreword supplies background information and hypothetical removal cost estimates. The approach used to conduct the jail removal cost study…

  7. Blanket comparison and selection study. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    1983-10-01

    This volume contains extensive data for the following chapters: (1) solid breeder tritium recovery, (2) solid breeder blanket designs, (3) alternate blanket concept screening, and (4) safety analysis. The following appendices are also included: (1) blanket design guidelines, (2) power conversion systems, (3) helium-cooled, vanadium alloy structure blanket design, (4) high wall loading study, and (5) molten salt safety studies. (MOW)

  8. Satellite Communication.

    Science.gov (United States)

    Technology Teacher, 1985

    1985-01-01

    Presents a discussion of communication satellites: explains the principles of satellite communication, describes examples of how governments and industries are currently applying communication satellites, analyzes issues confronting satellite communication, links mathematics and science to the study of satellite communication, and applies…

  9. Thicknesses and volumes of glaciers in the Andes of Peru estimated with satellite data and digital terrain information

    Science.gov (United States)

    Torres, Judith; Colonia, Daniel; Haeberli, Wilfried; Giráldez, Claudia; Frey, Holger; Huggel, Christian

    2014-05-01

    The glaciers in the tropical Andes of Peru have been melting at an unprecedented rate in recent years and generally after the Little Ice Age, a cold period that lasted from the 16th to the 19th century. Knowledge of glacier thicknesses and volumes is necessary for evaluating possible future scenarios of glacier shrinkage and of water supply to the Andean populations under conditions of continued warming. Calculation of glacier volumes for 19 mountain ranges in Perú has been based on two ice- thickness modeling methods including an area-related approach with different parameterizations and a slope-dependent approach. Both methods allow for rapid treatment of regional data obtained from satellite imagery and a Digital Elevation Model, integrated into a Geographic Information System. In addition, glacier outlines were obtained from the glacier inventory compiled by the Unit of Glaciology and Water Resources (UGRH) - National Water Authority (ANA) that used satellite imagery (ASTER, SPOT and LISS III from 2003 to 2010) and topographic information acquired from the cartography of the National Geographical Institute (IGN). The volume-area scaling approach resulted in glacier volume of 35.00 km3 and a total volume of 34.39 km3 resulted from the slope-dependent thickness with a thickness approximately 30 m. Estimated results also show a loss of the total ice surface ~42% and glacier volume loss about ~38% in both methods based on the first Glacier Inventory of Peru (from aerial photographs 1962 -1970) performed by HIDRANDINA SA. The results also indicate that volume estimations are subject to large uncertainties. Field measurements of glacier thickness are scarce and locally restricted due to rugged topography, high altitude and heavy crevassing of glaciers. Possibilities of calibrating and validating the applied model approaches are therefore limited. New possibilities nevertheless come into play with slope-dependent approaches, which lead beyond area-related average

  10. TOTAL WOOD VOLUME ESTIMATION OF EUCALYPTUS SPECIES BY IMAGES OF LANDSAT SATELLITE

    Directory of Open Access Journals (Sweden)

    Elias Fernando Berra

    2012-12-01

    Full Text Available http://dx.doi.org/10.5902/198050987566Models relating spectral answers with biophysical parameters aim estimate variables, like wood volume, without the necessity of frequent field measurements. The objective was to develop models to estimate wood volume by Landsat 5 TM images, supported by regional forest inventory data. The image was geo-referenced and converted to spectral reflectance. After, the images-index NDVI (Normalized Difference Vegetation Index and SR (Simple Ratio was generated. The reflectance values of the bands (TM1, TM2, TM3 e TM4 and of the indices (NDVI and SR was related with the wood volume. The biggest correlation with volume was with the NDVI and SR indices. The variables selection was made by Stepwise method, which returned three regression models as significant to explain the variation in volume. Finally, the best fitted model was selected (volume = -830,95 + 46,05 (SR + 107,47 (TM2, which was applied on the Landsat image where the pixels had started to represent the estimated volume in m³/ha on the Eucalyptus sp. production units. This model, significant at 95% confidence level, explains 68% of the wood volume variation.

  11. Gravimetric geodesy and sea surface topography studies by means of satellite-to-satellite tracking and satellite altimetry

    Science.gov (United States)

    Siry, J. W.

    1972-01-01

    A satellite-to-satellite tracking experiment is planned between ATS-F and GEOS-C with a range accuracy of 2-meters and a range rate accuracy of 0.035 centimeters per second for a 10-second integration time. This experiment is planned for 1974. It is anticipated that it will improve the spatial resolution of the satellite geoid by half an order of magnitude to about 6 degrees. Longer integration times should also permit a modest increase in the acceleration resolution. Satellite altimeter data will also be obtained by means of GEOS-C. An overall accuracy of 5-meters in altitude is the goal. The altimeter, per se, is expected to have an instrumental precision of about 2 meters, and an additional capability to observe with a precision of about 0.2 meters for limited periods.

  12. Orbital rotations of a satellite. Case study: GOCE

    Science.gov (United States)

    Baur, O.; Grafarend, E. W.

    Considering a satellite orbit as a space curve in terms of Differential Geometry, we succeeded to merge orbital rotation and curvature/torsion by means of Cartan connection. Here we transform the Frenet frame of reference of the space curve to the Kepler frame of reference ("along track", "cross track", "quasi-radial") of the satellite orbit by means of Meusnier's Lemma. As a case study, we identify the spectrum of orbital rotation frequencies relative to a GOCE satellite configuration. In particular, we identify more than one rotational period. For a moving frame of reference of type Frenet, periods in the range of the time of revolution of the satellite as well as half the time of revolution appear, whereas even periods of a third the revolution time become visible for the Kepler frame of reference. We describe moving frame rotations with respect to the quasi-inertial frame of reference, namely the angular velocities around the base vectors, by means of curvature measures. This allows to calculate frame rotations by geometric orbit information only (GPS track), i.e. apart from gradiometer measurements. Among other things, we identify the angular velocity relative to the second base vector becoming strictly zero in case of the Frenet frame of reference.

  13. Assessing the Suitability of Future Multi- and Hyperspectral Satellite Systems for Mapping the Spatial Distribution of Norway Spruce Timber Volume

    Directory of Open Access Journals (Sweden)

    Sascha Nink

    2015-09-01

    Full Text Available The availability of accurate and timely information on timber volume is important for supporting operational forest management. One option is to combine statistical concepts (e.g., small area estimates with specifically designed terrestrial sampling strategies to provide estimations also on the level of administrative units such as forest districts. This may suffice for economic assessments, but still fails to provide spatially explicit information on the distribution of timber volume within these management units. This type of information, however, is needed for decision-makers to design and implement appropriate management operations. The German federal state of Rhineland-Palatinate is currently implementing an object-oriented database that will also allow the direct integration of Earth observation data products. This work analyzes the suitability of forthcoming multi- and hyperspectral satellite imaging systems for producing local distribution maps for timber volume of Norway spruce, one of the most economically important tree species. In combination with site-specific inventory data, fully processed hyperspectral data sets (HyMap were used to simulate datasets of the forthcoming EnMAP and Sentinel-2 systems to establish adequate models for estimating timber volume maps. The analysis included PLS regression and the k-NN method. Root Mean Square Errors between 21.6% and 26.5% were obtained, where k-NN performed slightly better than PLSR. It was concluded that the datasets of both simulated sensor systems fulfill accuracy requirements to support local forest management operations and could be used in synergy. Sentinel-2 can provide meaningful volume distribution maps in higher geometric resolution, while EnMAP, due to its hyperspectral coverage, can contribute complementary information, e.g., on biophysical conditions.

  14. The RAAF Logistics Study. Volume 4,

    Science.gov (United States)

    1986-10-01

    Use of Issue-Based Root Definitions Application of Soft Systems Methodology to 27 Information Systems Analysis Conclusion 30 LIST OF ABBREVIATIONS 58 k...Management Control Systems’, Journal of Applied Systems Analysis, Volume 6, 1979, pages 51 to 67. 5. The soft systems methodology was developed to tackle...the soft systems methodology has many advantages whi-h recmmenrl it to this type of study area, it does not mcklel the timo ev, lut i, n :-f a system

  15. The Preliminary Design of a Standardized Spacecraft Bus for Small Tactical Satellites (Volume 2)

    Science.gov (United States)

    1996-11-01

    were to be added, the cost-reliability advantage of commercial-class with redundancy would be reduced. 15.2.6 Conclusion Given today’s push towards...October 1996. 60. Jeffrey, W. "Small Satellites (MSTI-3) for Remote Sensing: Pushing the Limits of Sensor and Bus Technology", SPIE Proceedings...California: The Aerospace Corporation, 1991. 148.U.S. Air Force Home Page, 1996: http://www.af.mil. 409 149.U.S. Congress, Office of Tecnology Assesment

  16. Air Quality Study Using Satellites - Current Capability and Future Plans

    Science.gov (United States)

    Bhartia, Pawan K.; Joiner, Joanna; Gleason, James; Liu, Xiong; Torres, Omar; Krotkov, Nickolay; Ziemke, Jerry; Chandra, Sushil

    2008-01-01

    Satellite instruments have had great success in monitoring the stratospheric ozone and in understanding the processes that control its daily to decadal scale variations. This field is now reaching its zenith with a number of satellite instruments from the US, Europe and Canada capping several decades of active research in this field. The primary public policy imperative of this research was to make reliable prediction of increases in biologically active surface UV radiation due to human activity. By contrast retrieval from satellite data of atmospheric constituents and photo-chemically active radiation that affect air quality is a new and growing field that is presenting us with unique challenges in measurement and data interpretation. A key distinction compared to stratospheric sensors is the greatly enhanced role of clouds, aerosols, and surfaces (CAS) in determining the quality and quantity of useful data that is available for air quality research. In our presentation we will use data from several sensors that are currently flying on the A-train satellite constellation, including OMI, MODIS, CLOUDSAT, and CALIPSO, to highlight that CAS can have both positive and negative effects on the information content of satellite measurements. This is in sharp contrast to other fields of remote sensing where CAS are usually considered an interference except in those cases when they are the primary subject of study. Our analysis has revealed that in the reflected wavelengths one often sees much further down into the atmosphere, through most cirrus, than one does in the emitted wavelengths. The lower level clouds provide a nice background against which one can track long-range transport of trace gases and aerosols. In addition, differences in trace gas columns estimated over cloudy and adjacent clear pixels can be used to measure boundary layer trace gases. However, in order to take full advantage of these features it will be necessary to greatly advance our understanding of

  17. Personal Access Satellite System (PASS) study. Fiscal year 1989 results

    Science.gov (United States)

    Sue, Miles K. (Editor)

    1990-01-01

    The Jet Propulsion Laboratory is exploring the potential and feasibility of a personal access satellite system (PASS) that will offer the user greater freedom and mobility than existing or currently planned communications systems. Studies performed in prior years resulted in a strawman design and the identification of technologies that are critical to the successful implementation of PASS. The study efforts in FY-89 were directed towards alternative design options with the objective of either improving the system performance or alleviating the constraints on the user terminal. The various design options and system issues studied this year and the results of the study are presented.

  18. Developing an Ice Volume Estimate of Jarvis Glacier, Alaska, using Ground-Penetrating Radar and High Resolution Satellite Imagery

    Science.gov (United States)

    Wu, N. L.; Campbell, S. W.; Douglas, T. A.; Osterberg, E. C.

    2013-12-01

    Jarvis Glacier is an important water source for Fort Greely and Delta Junction, Alaska. Yet with warming summer temperatures caused by climate change, the glacier is melting rapidly. Growing concern of a dwindling water supply has caused significant research efforts towards determining future water resources from spring melt and glacier runoff which feeds the community on a yearly basis. The main objective of this project was to determine the total volume of the Jarvis Glacier. In April 2012, a centerline profile of the Jarvis Glacier and 15 km of 100 MHz ground-penetrating radar (GPR) profiles were collected in cross sections to provide ice depth measurements. These depth measurements were combined with an interpreted glacier boundary (depth = 0 m) from recently collected high resolution WorldView satellite imagery to estimate total ice volume. Ice volume was calculated at 0.62 km3 over a surface area of 8.82 km2. However, it is likely that more glacier-ice exists within Jarvis Glacier watershed considering the value calculated with GPR profiles accounts for only the glacier ice within the valley and not for the valley side wall ice. The GLIMS glacier area database suggests that the valley accounts for approximately 50% of the total ice covered watershed. Hence, we are currently working to improve total ice volume estimates which incorporate the surrounding valley walls. Results from this project will be used in conjunction with climate change estimates and hydrological properties downstream of the glacier to estimate future water resources available to Fort Greely and Delta Junction.

  19. A study of multiple access schemes in satellite control network

    Science.gov (United States)

    Mo, Zijian; Wang, Zhonghai; Xiang, Xingyu; Wang, Gang; Chen, Genshe; Nguyen, Tien; Pham, Khanh; Blasch, Erik

    2016-05-01

    Satellite Control Networks (SCN) have provided launch control for space lift vehicles; tracking, telemetry and commanding (TTC) for on-orbit satellites; and, test support for space experiments since the 1960s. Currently, SCNs encounter a new challenge: how to maintain the high reliability of services when sharing the spectrum with emerging commercial services. To achieve this goal, the capability of multiple satellites reception is deserved as an update/modernization of SCN in the future. In this paper, we conducts an investigation of multiple access techniques in SCN scenario, e.g., frequency division multiple access (FDMA) and coded division multiple access (CDMA). First, we introduce two upgrade options of SCN based on FDMA and CDMA techniques. Correspondingly, we also provide their performance analysis, especially the system improvement in spectrum efficiency and interference mitigation. Finally, to determine the optimum upgrade option, this work uses CRISP, i.e., Cost, Risk, Installation, Supportability and Performance, as the baseline approach for a comprehensive trade study of these two options. Extensive numerical and simulation results are presented to illustrate the theoretical development.

  20. Simobiz-Simulation Tool to Study the Impact of Small Satellites in Mobile Market

    Science.gov (United States)

    Burlacu, M.-M.; Kohlenberg, J.; Prathaban, M.

    2008-08-01

    Interest in small satellites is growing fast world- wide. Businesses, governments, universities and other organizations around the world are starting their own small satellite programs. The surveys conducted by the space agencies and universities shows a promising increase in the use of small satellites for commercial applications. More number of operators offers or plans to offer mobile phone services by satellite. With the help of cost effective small satellite, mobile operators can be able to provide the services cheaper. Hence, it is always interesting to study the effect of low cost small satellite over the mobile market. In this article, we present SmartSim (Small Satellites Mobile Market Simulator) - the new module of Simobiz business simulation game, in which we have implemented two operators, a normal satellite operator and a nanosatellite operator, with specific terminals and services. Our main focus in this work is to understand the future market of small satellite in mobile telecommunication network.

  1. Photometric Studies of Rapidly Spinning Decommissioned GEO Satellites

    Science.gov (United States)

    Ryan, W.; Ryan, E.

    A satellites general characteristics can be substantially influenced by changes in the space environment. Rapidly spinning decommissioned satellites provide an excellent opportunity to study the rotation-dependent physical processes that affect a resident space objects (RSO) spin kinematics over time. Specifically, inactive satellites at or near geosynchronous Earth-orbit (GEO) provide easy targets for which high quality data can be collected and analyzed such that small differences can be detected under single-year or less time frames. Previous workers have shown that the rotational periods of defunct GEOs have been changing over time [1]. Further, the Yarkovsky-OKeefe-Radzievskii-Paddak (YORP) effect, a phenomenon which has been well-studied in the context of the changing the spin states of asteroids, has recently been suggested to be the cause of secular alterations in the rotational period of inactive satellites [2]. Researchers at the Magdalena Ridge Observatory 2.4-meter telescope (operated by the New Mexico Institute of Mining and Technology) have been investigating the spins states of retired GEOs and other high altitude space debris since 2007 [3]. In this current work, the 2.4-meter telescope was used to track and observe the objects typically over a one- to two-hour period, repeated several times over the course of weeks. When feasible, this is then repeated on a yearly basis. Data is taken with a 1 second cadence, nominally in groups of three 600 second image sets. With the current equipment, the cadence of the image sequences is very precise while the start time is accurate only to the nearest second. Therefore, periods are determined individually using each image sequence. Repeatability of the period determination for each of these sequences is typically on the order of 0.01 second or better for objects where a single period is identified. Spin rate periods determined from the GEO light curves collected thus far have been found to range from ~3 sec to

  2. A Comparative Study of Actuator Configurations for Satellite Attitude Control

    Directory of Open Access Journals (Sweden)

    Raymond Kristiansen

    2005-10-01

    Full Text Available In this paper a controllability study of different actuator configurations consisting of magnetic torquers, reaction wheels and a gravity boom is presented. The theoretical analysis is performed with use of controllability gramians, and simulation results with the different configurations are presented and compared regarding settling time and power consumption to substantiate the theoretical analysis. A reference model is also introduced to show how the power consumption can he lowered to the same magnitude as when magnetic torquers are used, without degrading the satellite response significantly.

  3. Floated pallet definition study. Volume 4: Summary volume

    Science.gov (United States)

    1975-01-01

    The conceptual design of a suspension system for the Floated Pallet and a retention system to support the pallet during launch, maneuvering and descent are described. In addition, a control moment gyroscope support equipment configuration study including installation and an experiment mount and erection study was performed. The impact of these separate hardware studies on the existing pallet configuration was assessed and a modified pallet common module defined.

  4. Greenland ice sheet melt area, volume, and runoff from satellite and in situ observations

    Science.gov (United States)

    van As, D.; Box, J. E.; Fausto, R. S.; Petersen, D.; Citterio, M.; Ahlstrom, A. P.; Andersen, S. B.; Steffen, K.

    2013-12-01

    Remote sensing provides surface melt area and regional mass change. In situ automatic weather station (AWS) data provide a relatively precise, but very local surface mass budget. Combining the two methods allows melt quantification for the entire Greenland ice sheet. We use interpolated near-surface air temperature from the GC-Net and PROMICE AWS networks, and remotely-sensed MODIS surface albedo to calculate melt with a temperature/albedo-index melt model. The calculations make use of albedo, combined with top-of-the-atmosphere solar radiation and cloud cover, to take into account absorbed shortwave radiation, the dominant melt parameter. In so doing the darkening due to the melt-albedo feedback is accounted. Calculated ablation is calibrated using AWS data. Assuming that surface albedo is a first-order indicator of the firn's available pore space and cold content, refreezing is parameterized as a function of it. Meltwater runoff for selected catchments is validated with river discharge data. The product: observation-based daily maps of near-surface air temperature, melt (extent and volume), and runoff for the Greenland ice sheet.

  5. Study on feasibility of laser reflective tomography with satellite-accompany

    Science.gov (United States)

    Gu, Yu; Hu, Yi-hua; Hao, Shi-qi; Gu, You-lin; Zhao, Nan-xiang; Wang, Yang-yang

    2015-10-01

    Laser reflective tomography is a long-range, high-resolution active detection technology, whose advantage is that the spatial resolution is unrelated with the imaging distance. Accompany satellite is a specific satellite around the target spacecraft with encircling movement. When using the accompany satellite to detect the target aircraft, multi-angle echo data can be obtained with the application of reflective tomography imaging. The feasibility of such detection working mode was studied in this article. Accompany orbit model was established with horizontal circular fleet and the parameters of accompany flight was defined. The simulation of satellite-to-satellite reflective tomography imaging with satellite-accompany was carried out. The operating mode of reflective tomographic data acquisition from monostatic laser radar was discussed and designed. The flight period, which equals to the all direction received data consuming time, is one of the important accompany flight parameters. The azimuth angle determines the plane of image formation while the elevation angle determines the projection direction. Both of the azimuth and elevation angles guide the satellite attitude stability controller in order to point the laser radar spot on the target. The influences of distance between accompany satellite and target satellite on tomographic imaging consuming time was analyzed. The influences of flight period, azimuth angle and elevation angle on tomographic imaging were analyzed as well. Simulation results showed that the satellite-accompany laser reflective tomography is a feasible and effective method to the satellite-to-satellite detection.

  6. Assessment of Satellite Images for Soil Salinity Studies

    Directory of Open Access Journals (Sweden)

    S.H. Sanaeinejad

    2012-04-01

    Full Text Available Soil salinity is one of the main environmental problems affecting extensive area in the world. There are some problems with traditional data collection methods for soil studies. Using the new methods and techniques such as remote sensing could overcome most of these problems. However using these data in areas with uncommon usages needed some researches to find the best calibration between the data and real situations in soil. This research was carried out using Landsat satellite images in Neyshabour area, North East of Iran. In order to prepare suitable learning samples for the image processing in this study, 300 locations were randomly selected in the area, among which 273 locations were finally selected as suitable surface soil samples. All samples were moved to laboratory and their electrical conductivity was measured. Six reflective bands of ETM+ satellite images taken from the study area in 2002 were used for the image processing analysis. Classification of different soil salinities was carried out using common algorithms of image classification based on the best composition bands and using statistical methods between soil salinity variables and digital numbers of the images to represent a suitable method. the research results showed that the reflective bands 7, 3, 4 and 1 are the best band composition for preparing the color composite images and for the classification of the salinity in this area. The highest coefficient of determination was R2=0.311 and R2=0.44 for saline and non-saline soil respectively using band 2 and 3 of the images at 5% significant level. Based on the results, it can be concluded that the potential of ETM+ images for delineation and identification of different soil salinity are limited.

  7. An Original Processing Method of Satellite Altimetry for Estimating Water Levels and Volume Fluctuations in a Series of Small Lakes of the Pantanal Wetland Complex in Brazil

    Science.gov (United States)

    Henrique Costa, Paulo; Oliveira Pereira, Eric; Maillard, Philippe

    2016-06-01

    Satellite altimetry is becoming a major tool for measuring water levels in rivers and lakes offering accuracies compatible with many hydrological applications, especially in uninhabited regions of difficult access. The Pantanal is considered the largest tropical wetland in the world and the sparsity of in situ gauging station make remote methods of water level measurements an attractive alternative. This article describes how satellites altimetry data from Envisat and Saral was used to determine water level in two small lakes in the Pantanal. By combining the water level with the water surface area extracted from satellite imagery, water volume fluctuations were also estimated for a few periods. The available algorithms (retrackers) that compute a range solution from the raw waveforms do not always produce reliable measurements in small lakes. This is because the return signal gets often "contaminated" by the surrounding land. To try to solve this, we created a "lake" retracker that rejects waveforms that cannot be attributed to "calm water" and convert them to altitude. Elevation data are stored in a database along with the water surface area to compute the volume fluctuations. Satellite water level time series were also produced and compared with the only nearby in situ gauging station. Although the "lake" retracker worked well with calm water, the presence of waves and other factors was such that the standard "ice1" retracker performed better on the overall. We estimate our water level accuracy to be around 75 cm. Although the return time of both satellites is only 35 days, the next few years promise to bring new altimetry satellite missions that will significantly increase this frequency.

  8. Investigation of Adaptive-threshold Approaches for Determining Area-Time Integrals from Satellite Infrared Data to Estimate Convective Rain Volumes

    Science.gov (United States)

    Smith, Paul L.; VonderHaar, Thomas H.

    1996-01-01

    The principal goal of this project is to establish relationships that would allow application of area-time integral (ATI) calculations based upon satellite data to estimate rainfall volumes. The research is being carried out as a collaborative effort between the two participating organizations, with the satellite data analysis to determine values for the ATIs being done primarily by the STC-METSAT scientists and the associated radar data analysis to determine the 'ground-truth' rainfall estimates being done primarily at the South Dakota School of Mines and Technology (SDSM&T). Synthesis of the two separate kinds of data and investigation of the resulting rainfall-versus-ATI relationships is then carried out jointly. The research has been pursued using two different approaches, which for convenience can be designated as the 'fixed-threshold approach' and the 'adaptive-threshold approach'. In the former, an attempt is made to determine a single temperature threshold in the satellite infrared data that would yield ATI values for identifiable cloud clusters which are closely related to the corresponding rainfall amounts as determined by radar. Work on the second, or 'adaptive-threshold', approach for determining the satellite ATI values has explored two avenues: (1) attempt involved choosing IR thresholds to match the satellite ATI values with ones separately calculated from the radar data on a case basis; and (2) an attempt involved a striaghtforward screening analysis to determine the (fixed) offset that would lead to the strongest correlation and lowest standard error of estimate in the relationship between the satellite ATI values and the corresponding rainfall volumes.

  9. Study on fault locating technology for satellite power system

    Institute of Scientific and Technical Information of China (English)

    LONG Bing; JIANG Xing-wei; SONG Zheng-ji

    2005-01-01

    It is currently prevalent to locate faults for a satellite power system based on an expert system, not utilizing all the available information provided by tests. The casual network model for a satellite power system is presented. Considerations for failure probability of each component of the power system, the cost of applying each test, the influence of a precedent test result on the next test selection, and an optimal sequential testing algorithm for fault location is presented. This program is applied to locate the failure component of the power system of a satellite. The results show this program is very effective and it is very fast to generate an optimal diagnosis tree.

  10. Next generation communications satellites: multiple access and network studies

    Science.gov (United States)

    Meadows, H. E.; Schwartz, M.; Stern, T. E.; Ganguly, S.; Kraimeche, B.; Matsuo, K.; Gopal, I.

    1982-01-01

    Efficient resource allocation and network design for satellite systems serving heterogeneous user populations with large numbers of small direct-to-user Earth stations are discussed. Focus is on TDMA systems involving a high degree of frequency reuse by means of satellite-switched multiple beams (SSMB) with varying degrees of onboard processing. Algorithms for the efficient utilization of the satellite resources were developed. The effect of skewed traffic, overlapping beams and batched arrivals in packet-switched SSMB systems, integration of stream and bursty traffic, and optimal circuit scheduling in SSMB systems: performance bounds and computational complexity are discussed.

  11. Study on Service Level Management in Integrated Satellite Information Network

    Institute of Scientific and Technical Information of China (English)

    SHANG Rui-qiang; ZHAO Jian-li; WANG Guang-xing

    2005-01-01

    Integrated Satellite Information Network (ISIN) includes those nodes in space and those on ground. It is the way to realize the fusion of satellite communication and traditional network technology. A satellite network management system based on Multiplex Network Management Protocol (MNMP) has accomplished traditional management, such as configuration, performance and fault management. An architecture of Service Level Management (SLM) in ISIN is proposed, and a service topology management and Service Level Agreement (SLA) are deeply researched. At last, service security and fault management are briefly discussed, and a simulation system is accomplished.

  12. Use of charging control guidelines for geosynchronous satellite design studies

    Science.gov (United States)

    Steves, N. J.

    1980-01-01

    Several of the principle guidelines from the Spacecraft Charging Design Guidelines Handbook are presented with illustrative examples. Use of the geomagnetic substorm specification to qualify satellite designs, the evaluation of satellite designs by using analytical modelling techniques, the use of selected materials and coatings to minimize charging, the tying of all conducting elements to a common ground, and the use of electrical filtering to protect circuits from discharge induced upsets are discussed. Discharge criteria and SCATHA data are excluded.

  13. Study of Some Strategies for Disposal of the GNSS Satellites

    Directory of Open Access Journals (Sweden)

    Diogo Merguizo Sanchez

    2015-01-01

    Full Text Available The complexity of the GNSS and the several types of satellites in the MEO region turns the creation of a definitive strategy to dispose the satellites of this system into a hard task. Each constellation of the system adopts its own disposal strategy; for example, in the American GPS, the disposal strategy consists in changing the altitude of the nonoperational satellites to 500 km above or below their nominal orbits. In this work, we propose simple but efficient techniques to discard satellites of the GNSS by exploiting Hohmann type maneuvers combined with the use of the 2ω˙+Ω˙≈0 resonance to increase its orbital eccentricity, thus promoting atmospheric reentry. The results are shown in terms of the increment of velocity required to transfer the satellites to the new orbits. Some comparisons with direct disposal maneuvers (Hohmann type are also presented. We use the exact equations of motion, considering the perturbations of the Sun, the Moon, and the solar radiation pressure. The geopotential model was considered up to order and degree eight. We showed the quantitative influence of the sun and the moon on the orbit of these satellites by using the method of the integral of the forces over the time.

  14. Wildland fire management. Volume 2: Wildland fire control 1985-1995. [satellite information system for California fire problems

    Science.gov (United States)

    Saveker, D. R. (Editor)

    1973-01-01

    The preliminary design of a satellite plus computer earth resources information system is proposed for potential uses in fire prevention and control in the wildland fire community. Suggested are satellite characteristics, sensor characteristics, discrimination algorithms, data communication techniques, data processing requirements, display characteristics, and costs in achieving the integrated wildland fire information system.

  15. Study of the NWC electrons belt observed on DEMETER Satellite

    CERN Document Server

    Li, Xinqiao; Wang, Ping; Wang, Huanyu; Lu, Hong; Zhang, Xuemin; Huang, Jianping; Shi, Feng; Yu, Xiaoxia; Xu, Yanbing; Meng, Xiangcheng; Wang, Hui; Zhao, Xiaoyun; Parrot, M

    2010-01-01

    We analyzed the data from 2007 to 2008, which is observed by IDP onboard DEMETER satellite, during ten months of NWC working and seven months of NWC shutdown. The characteristic of the space instantaneous electron belts, which come from the influence of the VLF transmitted by NWC, is studied comprehensively. The main distribution region of the NWC electron belts and the flux change are given. We also studied the distribution characteristic of the average energy spectrum in different magnetic shell at the height of DEMETER orbit and the difference of the average energy spectrum of the electrons in the drift loss-cone between day and night. As a result, the powerful power of NWC transmitter and the 19.8 kHz narrow bandwidth VLF emission not only created a momentary electrons enhancement region, which strides 180 degree in them longitude direction and from 1.6 to 1.9 in L value, with the rise of the electrons flux reaching to 3 orders of magnitude mostly, but also induced the enhancement or loss of electrons in ...

  16. Versatile Satellite Architecture and Technology: A New Architecture for Low Cost Satellite Missions for Solar-Terrestrial Studies

    Science.gov (United States)

    Cook, T. A.; Chakrabarti, S.; Polidan, R.; Jaeger, T.; Hill, L.

    2011-12-01

    Early in the 20th century, automobiles appeared as extraordinary vehicles - and now they are part of life everywhere. Late in the 20th century, internet and portable phones appeared as innovations - and now omni-present requirements. At mid-century, the first satellites were launched into space - and now 50 years later - "making a satellite" remains in the domain of highly infrequent events. Why do all universities and companies not have their own satellites? Why is the work force capable of doing so remarkably small? Why do highly focused science objectives that require just a glimpse from space never get a chance to fly? Historically, there have been two primary impediments to place an experiment in orbit - high launch costs and the high cost of spacecraft systems and related processes. The first problem appears to have been addressed through the availability of several low-cost (< $10M) commercial launch opportunities. The Versatile Satellite Architecture and Technology (VerSAT) will address the second. Today's space missions are often large, complex and require development times typically a decade from conception to execution. In present risk-averse scenario, the huge expense of these one-of-a-kind mission architecture can only be justified if the technology required to make orders of magnitude gains is flight-proven at the time mission conception. VerSAT will complement these expensive missions which are "too large to fail" and the CUBESATs. A number of Geospace science experiments that could immediately take advantage of VerSAT have been identified. They range from the study of fundamental questions of the "ignorosphere" from a single satellite lasting a few days - a region of space that was probed once about 40 years ago, to a constellation of satellites which will disentangle the space and time ambiguity of the variability of ionospheric structures and their link to the storms in the Sun to long-term studies of the Sun-Earth system. VerSAT is a true

  17. Satellite-Based Study of Glaciers Retreat in Northern Pakistan

    Science.gov (United States)

    Munir, Siraj

    Glaciers serve as a natural regulator of regional water supplies. About 16933 Km 2 area of glaciers is covered by Pakistan. These glaciers are enormous reservoirs of fresh water and their meltwater is an important resource which feed rivers in Pakistan. Glacier depletion, especially recent melting can affect agriculture, drinking water supplies, hydro-electric power, and ecological habitats. This can also have a more immediate impact on Pakistan's economy that depends mainly on water from glacier melt. Melting of seasonal snowfall and permanent glaciers has resulted not only in reduction of water resources but also caused flash floods in many areas of Pakistan. With the advent of satellite technology, using optical and SAR data the study of glaciers, has become possible. Using temporal data, based on calculation of snow index, band ratios and texture reflectance it has been revealed that the rate of glacier melting has increased as a consequent of global warming. Comparison of Landsat images of Batura glacier for October 1992 and October 2000 has revealed that there is a decrease of about 17 sq km in Batura glaciers. Although accurate changes in glacier extent cannot be assessed without baseline information, these efforts have been made to analyze future changes in glaciated area.

  18. Study of Remote Globular Cluster Satellites of M87

    Science.gov (United States)

    Sahai, Arushi; Shao, Andrew; Toloba, Elisa; Guhathakurta, Puragra; Peng, Eric W.; Zhang, Hao

    2017-01-01

    We present a sample of “orphan” globular clusters (GCs) with previously unknown parent galaxies, which we determine to be remote satellites of M87, a massive elliptical galaxy at the center of the Virgo Cluster of Galaxies. Because GCs were formed in the early universe along with their original parent galaxies, which were cannibalized by massive galaxies such as M87, they share similar age and chemical properties. In this study, we first confirm that M87 is the adoptive parent galaxy of our orphan GCs using photometric and spectroscopic data to analyze spatial and velocity distributions. Next, we increase the signal-to-noise ratio of our samples’ spectra through a process known as coaddition. We utilize spectroscopic absorption lines to determine the age and metallicity of our orphan GCs through comparison to stellar population synthesis models, which we then relate to the GCs’ original parent galaxies using a mass-metallicity relation. Our finding that remote GCs of M87 likely developed in galaxies with ~1010 solar masses implies that M87’s outer halo is formed of relatively massive galaxies, serving as important parameters for developing theories about the formation and evolution of massive galaxies.This research was funded in part by NASA/STScI and the National Science Foundation. Most of this work was carried out by high school students working under the auspices of the Science Internship Program at UC Santa Cruz.

  19. Nuclear Aircraft Feasibility Study. Volume 1

    Science.gov (United States)

    1975-03-01

    this device was as- sumed to have triple redundancy, and its weight, volume, and power requirements were added to the totals manually . Triple...Ref. 100, p. 342). However, they have not utilized the tempera - tures required for the airborne propulsion system. Helium cooled systems have been...i 500MG/C REACTOP COFELEMEIS OUTLET TCI T MPERATURE 2260oR H ^ 15.000 ^10.000 1~— 5.000 "^~^ 1,000 H S c •EFPH-E 1

  20. A Satellite Based Fog Study of the Korean Peninsula

    Science.gov (United States)

    2007-06-01

    total number of fog and fog likely days detected from the two MODIS satellites, Aqua and Tera , respectively. Results from all nine areas of...trends in fog detection based on the satellite differences. 46 0 20 40 60 80 100 120 N um be r o f D ay s 1 2 3 4 5 6 7 8 9 Areas Four Month Tera vs...Aqua Fog Totals Tera Fog Tera Fog Likely Aqua Fog Aqua Fog Likely Figure 29. Comparisons of the four month total number of fog and fog likely days

  1. Technical Report Series on Global Modeling and Data Assimilation. Volume 12; Comparison of Satellite Global Rainfall Algorithms

    Science.gov (United States)

    Suarez, Max J. (Editor); Chang, Alfred T. C.; Chiu, Long S.

    1997-01-01

    Seventeen months of rainfall data (August 1987-December 1988) from nine satellite rainfall algorithms (Adler, Chang, Kummerow, Prabhakara, Huffman, Spencer, Susskind, and Wu) were analyzed to examine the uncertainty of satellite-derived rainfall estimates. The variability among algorithms, measured as the standard deviation computed from the ensemble of algorithms, shows regions of high algorithm variability tend to coincide with regions of high rain rates. Histograms of pattern correlation (PC) between algorithms suggest a bimodal distribution, with separation at a PC-value of about 0.85. Applying this threshold as a criteria for similarity, our analyses show that algorithms using the same sensor or satellite input tend to be similar, suggesting the dominance of sampling errors in these satellite estimates.

  2. Terrestrial kilometric radiation: 1: Spatial structures studies. [from satellite observation (Explorer 2 satellite) of lunar occultation

    Science.gov (United States)

    Alexander, J. K.; Kaiser, M. L.

    1976-01-01

    Observations are presented of lunar occultations of the earth at 250 kHz obtained with the Radio-Astronomy-Explorer-2 satellite which were used to derive two dimensional maps of the location of the sources of terrestrial kilometric radiation (TKR). By examining the two dimensional source distributions as a function of the observer's location (lunar orbit) with respect to the magnetosphere, the average three dimensional location of the emission regions can be estimated. Although TKR events at 250 kHz can often be observed at projected distances corresponding to the 250 kHz electron gyro or plasma level (approximately 2 earth radii), many events are observed much farther from the earth (between 5 and 15 earth radii). Dayside emission apparently in the region of the polar cusp and the magnetosheath and night emission associated with regions of the magnetotail are examined. The nightside emission is suggestive of a mechanism involving plasma sheet electron precipitation in the pre-midnight sector.

  3. Design study report. Volume 2: Electronic unit

    Science.gov (United States)

    1973-01-01

    The recording system discussed is required to record and reproduce wideband data from either of the two primary Earth Resources Technology Satellite sensors: Return Beam Vidicon (RBV) camera or Multi-Spectral Scanner (MSS). The camera input is an analog signal with a bandwidth from dc to 3.5 MHz; this signal is accommodated through FM recording techniques which provide a recorder signal-to-noise ratio in excess of 39 db, black-to-white signal/rms noise, over the specified bandwidth. The MSS provides, as initial output, 26 narrowband channels. These channels are multiplexed prior to transmission, or recording, into a single 15 Megabit/second digital data stream. Within the recorder, the 15 Megabit/second NRZL signal is processed through the same FM electronics as the RBV signal, but the basic FM standards are modified to provide an internal, 10.5 MHz baseland response with signal-to-noise ratio of about 25 db. Following FM demodulation, however, the MSS signal is digitally re-shaped and re-clocked so that good bit stability and signal-to-noise exist at the recorder output.

  4. Advancements in satellite gravity gradient data for crustal studies

    NARCIS (Netherlands)

    Ebbing, J.; Bauman, J.; Fuchs, M.; Lieb, V.; Haagmans, R.; Meekes, J.A.C.; Abdul Fattah, R.

    2013-01-01

    In recent years, global gravity models, both based only on satellite data and from combination with terrestrial data, are increasingly available and particularly useful to construct regional models before more local interpretations on the exploration scale are carried out. Often it is challenging to

  5. Advancements in satellite gravity gradient data for crustal studies

    NARCIS (Netherlands)

    Ebbing, J.; Bauman, J.; Fuchs, M.; Lieb, V.; Haagmans, R.; Meekes, J.A.C.; Abdul Fattah, R.

    2013-01-01

    In recent years, global gravity models, both based only on satellite data and from combination with terrestrial data, are increasingly available and particularly useful to construct regional models before more local interpretations on the exploration scale are carried out. Often it is challenging to

  6. Mars power system concept definition study. Volume 1: Study results

    Science.gov (United States)

    Littman, Franklin D.

    1994-12-01

    A preliminary top level study was completed to define power system concepts applicable to Mars surface applications. This effort included definition of power system requirements and selection of power systems with the potential for high commonality. These power systems included dynamic isotope, Proton Exchange Membrane (PEM) regenerative fuel cell, sodium sulfur battery, photovoltaic, and reactor concepts. Design influencing factors were identified. Characterization studies were then done for each concept to determine system performance, size/volume, and mass. Operations studies were done to determine emplacement/deployment maintenance/servicing, and startup/shutdown requirements. Technology development roadmaps were written for each candidate power system (included in Volume 2). Example power system architectures were defined and compared on a mass basis. The dynamic isotope power system and nuclear reactor power system architectures had significantly lower total masses than the photovoltaic system architectures. Integrated development and deployment time phasing plans were completed for an example DIPS and reactor architecture option to determine the development strategies required to meet the mission scenario requirements.

  7. Satellite RNAs and Satellite Viruses.

    Science.gov (United States)

    Palukaitis, Peter

    2016-03-01

    Satellite RNAs and satellite viruses are extraviral components that can affect either the pathogenicity, the accumulation, or both of their associated viruses while themselves being dependent on the associated viruses as helper viruses for their infection. Most of these satellite RNAs are noncoding RNAs, and in many cases, have been shown to alter the interaction of their helper viruses with their hosts. In only a few cases have the functions of these satellite RNAs in such interactions been studied in detail. In particular, work on the satellite RNAs of Cucumber mosaic virus and Turnip crinkle virus have provided novel insights into RNAs functioning as noncoding RNAs. These effects are described and potential roles for satellite RNAs in the processes involved in symptom intensification or attenuation are discussed. In most cases, models describing these roles involve some aspect of RNA silencing or its suppression, either directly or indirectly involving the particular satellite RNA.

  8. SeaWiFS Technical Report Series. Volume 42; Satellite Primary Productivity Data and Algorithm Development: A Science Plan for Mission to Planet Earth

    Science.gov (United States)

    Falkowski, Paul G.; Behrenfeld, Michael J.; Esaias, Wayne E.; Balch, William; Campbell, Janet W.; Iverson, Richard L.; Kiefer, Dale A.; Morel, Andre; Yoder, James A.; Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor)

    1998-01-01

    Two issues regarding primary productivity, as it pertains to the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Program and the National Aeronautics and Space Administration (NASA) Mission to Planet Earth (MTPE) are presented in this volume. Chapter 1 describes the development of a science plan for deriving primary production for the world ocean using satellite measurements, by the Ocean Primary Productivity Working Group (OPPWG). Chapter 2 presents discussions by the same group, of algorithm classification, algorithm parameterization and data availability, algorithm testing and validation, and the benefits of a consensus primary productivity algorithm.

  9. Management approach recommendations. Earth Observatory Satellite system definition study (EOS)

    Science.gov (United States)

    1974-01-01

    Management analyses and tradeoffs were performed to determine the most cost effective management approach for the Earth Observatory Satellite (EOS) Phase C/D. The basic objectives of the management approach are identified. Some of the subjects considered are as follows: (1) contract startup phase, (2) project management control system, (3) configuration management, (4) quality control and reliability engineering requirements, and (5) the parts procurement program.

  10. A STUDY ON MORPHOMETRIC MEASUREMENT OF VOLUME OF ACETABULUM

    Directory of Open Access Journals (Sweden)

    Leena Khobragade,

    2014-09-01

    Full Text Available Background: Hip joint represents an unique functional unit and has complex biomechanical construction. In today’s era where total hip replacement surgeries have made their way it has become imperative for the anatomists to know the variations in acetabular dimensions. Reconstruction of acetabulum in patients with significant acetabular bone deficiency remains a challenge. Hence the present study was carried out with the aim to study the morphometric measurement of volume of acetabulum in both the sexes. Materials and Methods: Material of the study consisted of 110 human hip bones (60 males and 50 females. Volume of Acetabulum (VA was measured on these hip bones on both the sides. Statistical analysis was done using SPSS (Statistical Package for the Social Sciences version 11 and Microsoft Excel 2007. Results: The mean volume of acetabulum in male was 23.13 ml and female was 17.88 ml. The mean volume of acetabulum on right side was 20.55 ml and left side was 20.91 ml. Volume of the acetabulum was greater in males as compared to females and the differences were statistically significant. Volume was greater on the left side as compared to the right side but the difference was statistically non significant. Discussion: Analysing the differences on human acetabulum is helpful in understanding not only morphological but also medicolegal aspects. Conclusion: Volume of the acetabulum was greater in males as compared to females.

  11. A study of warm rain detection using A-Train satellite data

    National Research Council Canada - National Science Library

    Ruiyue Chen; Zhanqing Li; Robert J. Kuligowski; Ralph Ferraro; Fuzhong Weng

    2011-01-01

    .... This study exploits multi-sensor data from the A-Train satellite constellation to investigate the rain contribution from warm clouds and the potential of using cloud microphysical parameters for warm rain detection...

  12. A Study on the Timing Technology of Digital Satellite TV

    Science.gov (United States)

    Song, K. X.

    2013-03-01

    Based on analyzing and summarizing the modern timing technologies, through intensive analyzing the characteristics of the current digital satellite TV signals, and without changing equipment configuration of the digital satellite TV transmitter and signal system, this thesis puts forward the method of using the digital TV signal to transmit the standard time and frequency, and carries out the relevant researches on the key technologies. Meanwhile, we make experiments on the digital satellite TV timing system, which are based on the proposed timing method. Through analyzing the test data, the timing method is proved practicable and with a high precision. The main research work is as follows: (1) Firstly, we summarize the necessary conditions and key elements required for timing by analyzing the characteristics of modern timing methods, and analyze China’s digital satellite TV signal system; Secondly, we propose the idea that the inherent flag bit of source coding signals of TV is used to trigger event of timing and then complete this task; Thirdly, we propose the principle of transmitting the standard time and frequency through digital satellite TV signal, analyze the error sources which affect the accuracy of timing, and find the ways to reduce the error effect. (2) Synchronization clock signal is recovered from asynchronous serial interface (ASI) data to achieve bit synchronization, so that the transmitter can accurately access to the high-precision standard time code. At the same time, the TV signal transmission delay on the transmission channel is accurately measured in order to supply the necessary information for timing. Based on the analysis of the ASI data transmission characteristics and transmission standards, a method using over-sampling to recover the ASI clock signal and synchronize the digital TV signal source coding is proposed in this paper. This method is proved effective by the implementation on the FPGA (Field Programmable Gate Array). (3) Using

  13. Moderate intensity supine exercise causes decreased cardiac volumes and increased outer volume variations: a cardiovascular magnetic resonance study

    DEFF Research Database (Denmark)

    Steding-Ehrenborg, Katarina; Jablonowski, Robert; Arvidsson, Per M;

    2013-01-01

    The effects on left and right ventricular (LV, RV) volumes during physical exercise remains controversial. Furthermore, no previous study has investigated the effects of exercise on longitudinal contribution to stroke volume (SV) and the outer volume variation of the heart. The aim of this study...

  14. Toward lean satellites reliability improvement using HORYU-IV project as case study

    Science.gov (United States)

    Faure, Pauline; Tanaka, Atomu; Cho, Mengu

    2017-04-01

    Lean satellite programs are programs in which the satellite development philosophy is driven by fast delivery and low cost. Though this concept offers the possibility to develop and fly risky missions without jeopardizing a space program, most of these satellites suffer infant mortality and fail to achieve their mission minimum success. Lean satellites with high infant mortality rate indicate that testing prior to launch is insufficient. In this study, the authors monitored failures occurring during the development of the lean satellite HORYU-IV to identify the evolution of the cumulative number of failures against cumulative testing time. Moreover, the sub-systems driving the failures depending on the different development phases were identified. The results showed that half to 2/3 of the failures are discovered during the early stage of testing. Moreover, when the mean time before failure was calculated, it appeared that for any development phase considered, a new failure appears on average every 20 h of testing. Simulations were also performed and it showed that for an initial testing time of 50 h, reliability after 1 month launch can be improved by nearly 6 times as compared to an initial testing time of 20 h. Through this work, the authors aim at providing a qualitative reference for lean satellites developers to better help them manage resources to develop lean satellites following a fast delivery and low cost philosophy while ensuring sufficient reliability to achieve mission minimum success.

  15. Commencement Bay Study. Volume III. Fish Wetlands.

    Science.gov (United States)

    1981-12-31

    area. Amish (1976) studied the occurrence of Philometra americana in English sole and rock sole of central Puget Sound. Amish’s sampling locations...Fisheries Biologist, Washington Department of Fisheries. Personal communication. Amish , R.A., 1976. The occurrence of the bloodworm Philometra americana...wildlife as well as the people of the Puyallup Nation who then inhabited the study area. Six major wetland habitat types have been recognized in the

  16. Object-oriented industrial solid waste identification using HJ satellite imagery: a case study of phosphogypsum

    Science.gov (United States)

    Fu, Zhuo; Shen, Wenming; Xiao, Rulin; Xiong, Wencheng; Shi, Yuanli; Chen, Baisong

    2012-10-01

    The increasing volume of industrial solid wastes presents a critical problem for the global environment. In the detection and monitoring of these industrial solid wastes, the traditional field methods are generally expensive and time consuming. With the advantages of quick observations taken at a large area, remote sensing provides an effective means for detecting and monitoring the industrial solid wastes in a large scale. In this paper, we employ an object-oriented method for detecting the industrial solid waste from HJ satellite imagery. We select phosphogypsum which is a typical industrial solid waste as our target. Our study area is located in Fuquan in Guizhou province of China. The object oriented method we adopted consists of the following steps: 1) Multiresolution segmentation method is adopted to segment the remote sensing images for obtaining the object-based images. 2) Build the feature knowledge set of the object types. 3) Detect the industrial solid wastes based on the object-oriented decision tree rule set. We analyze the heterogeneity in features of different objects. According to the feature heterogeneity, an object-oriented decision tree rule set is then built for aiding the identification of industrial solid waste. Then, based on this decision tree rule set, the industrial solid waste can be identified automatically from remote sensing images. Finally, the identified results are validated using ground survey data. Experiments and results indicate that the object-oriented method provides an effective method for detecting industrial solid wastes.

  17. Derivation and Validation of Supraglacial Lake Volumes on the Greenland Ice Sheet from High-Resolution Satellite Imagery

    Science.gov (United States)

    Moussavi, Mahsa S.; Abdalati, Waleed; Pope, Allen; Scambos, Ted; Tedesco, Marco; MacFerrin, Michael; Grigsby, Shane

    2016-01-01

    Supraglacial meltwater lakes on the western Greenland Ice Sheet (GrIS) are critical components of its surface hydrology and surface mass balance, and they also affect its ice dynamics. Estimates of lake volume, however, are limited by the availability of in situ measurements of water depth,which in turn also limits the assessment of remotely sensed lake depths. Given the logistical difficulty of collecting physical bathymetric measurements, methods relying upon in situ data are generally restricted to small areas and thus their application to largescale studies is difficult to validate. Here, we produce and validate spaceborne estimates of supraglacial lake volumes across a relatively large area (1250 km(exp 2) of west Greenland's ablation region using data acquired by the WorldView-2 (WV-2) sensor, making use of both its stereo-imaging capability and its meter-scale resolution. We employ spectrally-derived depth retrieval models, which are either based on absolute reflectance (single-channel model) or a ratio of spectral reflectances in two bands (dual-channel model). These models are calibrated by usingWV-2multispectral imagery acquired early in the melt season and depth measurements from a high resolutionWV-2 DEM over the same lake basins when devoid of water. The calibrated models are then validated with different lakes in the area, for which we determined depths. Lake depth estimates based on measurements recorded in WV-2's blue (450-510 nm), green (510-580 nm), and red (630-690 nm) bands and dual-channel modes (blue/green, blue/red, and green/red band combinations) had near-zero bias, an average root-mean-squared deviation of 0.4 m (relative to post-drainage DEMs), and an average volumetric error of b1%. The approach outlined in this study - image-based calibration of depth-retrieval models - significantly improves spaceborne supraglacial bathymetry retrievals, which are completely independent from in situ measurements.

  18. Derivation and Validation of Supraglacial Lake Volumes on the Greenland Ice Sheet from High-Resolution Satellite Imagery

    Science.gov (United States)

    Moussavi, Mahsa S.; Abdalati, Waleed; Pope, Allen; Scambos, Ted; Tedesco, Marco; MacFerrin, Michael; Grigsby, Shane

    2016-01-01

    Supraglacial meltwater lakes on the western Greenland Ice Sheet (GrIS) are critical components of its surface hydrology and surface mass balance, and they also affect its ice dynamics. Estimates of lake volume, however, are limited by the availability of in situ measurements of water depth,which in turn also limits the assessment of remotely sensed lake depths. Given the logistical difficulty of collecting physical bathymetric measurements, methods relying upon in situ data are generally restricted to small areas and thus their application to largescale studies is difficult to validate. Here, we produce and validate spaceborne estimates of supraglacial lake volumes across a relatively large area (1250 km(exp 2) of west Greenland's ablation region using data acquired by the WorldView-2 (WV-2) sensor, making use of both its stereo-imaging capability and its meter-scale resolution. We employ spectrally-derived depth retrieval models, which are either based on absolute reflectance (single-channel model) or a ratio of spectral reflectances in two bands (dual-channel model). These models are calibrated by usingWV-2multispectral imagery acquired early in the melt season and depth measurements from a high resolutionWV-2 DEM over the same lake basins when devoid of water. The calibrated models are then validated with different lakes in the area, for which we determined depths. Lake depth estimates based on measurements recorded in WV-2's blue (450-510 nm), green (510-580 nm), and red (630-690 nm) bands and dual-channel modes (blue/green, blue/red, and green/red band combinations) had near-zero bias, an average root-mean-squared deviation of 0.4 m (relative to post-drainage DEMs), and an average volumetric error of b1%. The approach outlined in this study - image-based calibration of depth-retrieval models - significantly improves spaceborne supraglacial bathymetry retrievals, which are completely independent from in situ measurements.

  19. Space Biology Initiative. Trade Studies, volume 2

    Science.gov (United States)

    1989-01-01

    The six studies which are the subjects of this report are entitled: Design Modularity and Commonality; Modification of Existing Hardware (COTS) vs. New Hardware Build Cost Analysis; Automation Cost vs. Crew Utilization; Hardware Miniaturization versus Cost; Space Station Freedom/Spacelab Modules Compatibility vs. Cost; and Prototype Utilization in the Development of Space Hardware. The product of these six studies was intended to provide a knowledge base and methodology that enables equipment produced for the Space Biology Initiative program to meet specific design and functional requirements in the most efficient and cost effective form consistent with overall mission integration parameters. Each study promulgates rules of thumb, formulas, and matrices that serves as a handbook for the use and guidance of designers and engineers in design, development, and procurement of Space Biology Initiative (SBI) hardware and software.

  20. Space Biology Initiative. Trade Studies, volume 1

    Science.gov (United States)

    1989-01-01

    The six studies which are addressed are entitled: Design Modularity and Commonality; Modification of Existing Hardware (COTS) vs. New Hardware Build Cost Analysis; Automation Cost vs. Crew Utilization; Hardware Miniaturization versus Cost; Space Station Freedom/Spacelab Modules Compatibility vs. Cost; and Prototype Utilization in the Development of Space Hardware. The product of these six studies was intended to provide a knowledge base and methodology that enables equipment produced for the Space Biology Initiative program to meet specific design and functional requirements in the most efficient and cost effective form consistent with overall mission integration parameters. Each study promulgates rules of thumb, formulas, and matrices that serves has a handbook for the use and guidance of designers and engineers in design, development, and procurement of Space Biology Initiative (SBI) hardware and software.

  1. On the choice of orbits for an altimetric satellite to study ocean circulation and tides

    Science.gov (United States)

    Parke, Michael E.; Stewart, Robert H.; Farless, David L.; Cartwright, David E.

    1987-01-01

    The choice of an orbit for satellite altimetric studies of the ocean's circulation and tides requires an understanding of the orbital characteristics that influence the accuracy of the satellite's measurements of sea level and the temporal and spatial distribution of the measurements. The orbital characteristics that influence accurate calculations of the satellite's position as a function of time are examined, and the pattern of ground tracks laid down on the ocean's surface as a function of the satellite's altitude and inclination is studied. The results are used to examine the aliases in the measurements of surface geostrophic currents and tides. Finally, these considerations are used to specify possible orbits that may be useful for the upcoming Topex/Poseidon mission.

  2. National Television Violence Study. Volume 2.

    Science.gov (United States)

    Seawell, Margaret, Ed.

    The National Television Violence Study (NTVS) was a 3-year effort to assess the effects of violence on television, of particular interest to education professionals is the effects of television violence on children. Funded by the National Cable Television Association, the project began in June 1994 and involved the participation of media scholars…

  3. National Television Violence Study. Volume 3.

    Science.gov (United States)

    Seawell, Margaret, Ed.

    The National Television Violence Study (NTVS) was a 3-year effort to assess the effects of violence on television, of particular interest to education professionals is the effects of television violence on children. Funded by the National Cable Television Association, the project began in June 1994 and involved the participation of media scholars…

  4. National Television Violence Study. Volume 1.

    Science.gov (United States)

    Seawell, Margaret, Ed.

    The National Television Violence Study (NTVS) was a 3-year effort to assess the effects of violence on television, of particular interest to education professionals is the effects of television violence on children. Funded by the National Cable Television Association, the project began in June 1994 and involved the participation of media scholars…

  5. National Television Violence Study. Volume 2.

    Science.gov (United States)

    Seawell, Margaret, Ed.

    The National Television Violence Study (NTVS) was a 3-year effort to assess the effects of violence on television, of particular interest to education professionals is the effects of television violence on children. Funded by the National Cable Television Association, the project began in June 1994 and involved the participation of media scholars…

  6. National Television Violence Study. Volume 1.

    Science.gov (United States)

    Seawell, Margaret, Ed.

    The National Television Violence Study (NTVS) was a 3-year effort to assess the effects of violence on television, of particular interest to education professionals is the effects of television violence on children. Funded by the National Cable Television Association, the project began in June 1994 and involved the participation of media scholars…

  7. National Television Violence Study. Volume 3.

    Science.gov (United States)

    Seawell, Margaret, Ed.

    The National Television Violence Study (NTVS) was a 3-year effort to assess the effects of violence on television, of particular interest to education professionals is the effects of television violence on children. Funded by the National Cable Television Association, the project began in June 1994 and involved the participation of media scholars…

  8. Studies in Intelligence. Volume 55, Number 4

    Science.gov (United States)

    2011-12-01

    Merrill Company, 1946), 20. When the Japanese invaded Thailand on 8 December 1941, the Thai government under Prime Minister Phibun Songkhram aligned...Underground Kingdom. Indianapolis: The Bobbs- Merrill Company, 1946. OSS in Siam 22 Studies in Intelligence Vol. 55, No. 4 (Extracts, December 2011...not publicly gloat after the mis- sile crisis, but did crow to his friends about the payback Khrushchev received for his bul- lying behavior during

  9. Studies in Intelligence. Volume 57, Number 3

    Science.gov (United States)

    2013-09-01

    difficult adaptations. A suc- cessful translation often requires the presence of the original author or inventor of the technology to super- vise or conduct...Transactional View of Tacit Knowledge,” paper presented at October 2007 Society for Social Studies of Science annual meeting: http:== www .4sonline.org...the inventor and devel- oper of the technology. Despite the many papers the Berkeley group published on the cyclotron, including Lawrence’s Nobel

  10. Experimental study of mountain lee—waves by means of satellite photographs and aircraft measurements

    OpenAIRE

    Cruette, Denise

    2011-01-01

    This paper is a summary of a Ph.D. Thesis1 which was a systematic study of the influence of various meteorological factors on the occurrence and characteristics of mountain waves, more specifically of lee-waves of great horizontal extent. The data used are, beside classical meteorological informations, that given by satellite pictures completed by quasi-simultaneous measurements from planes or gliders. The analysis of many satellite pictures received at the french station of Lannion (Brittany...

  11. ICPP tank farm closure study. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Spaulding, B.C.; Gavalya, R.A.; Dahlmeir, M.M. [and others

    1998-02-01

    The disposition of INEEL radioactive wastes is now under a Settlement Agreement between the DOE and the State of Idaho. The Settlement Agreement requires that existing liquid sodium bearing waste (SBW), and other liquid waste inventories be treated by December 31, 2012. This agreement also requires that all HLW, including calcined waste, be disposed or made road ready to ship from the INEEL by 2035. Sodium bearing waste (SBW) is produced from decontamination operations and HLW from reprocessing of SNF. SBW and HLW are radioactive and hazardous mixed waste; the radioactive constituents are regulated by DOE and the hazardous constituents are regulated by the Resource Conservation and Recovery Act (RCRA). Calcined waste, a dry granular material, is produced in the New Waste Calcining Facility (NWCF). Two primary waste tank storage locations exist at the ICPP: Tank Farm Facility (TFF) and the Calcined Solids Storage Facility (CSSF). The TFF has the following underground storage tanks: four 18,400-gallon tanks (WM 100-102, WL 101); four 30,000-gallon tanks (WM 103-106); and eleven 300,000+ gallon tanks. This includes nine 300,000-gallon tanks (WM 182-190) and two 318,000 gallon tanks (WM 180-181). This study analyzes the closure and subsequent use of the eleven 300,000+ gallon tanks. The 18,400 and 30,000-gallon tanks were not included in the work scope and will be closed as a separate activity. This study was conducted to support the HLW Environmental Impact Statement (EIS) waste separations options and addresses closure of the 300,000-gallon liquid waste storage tanks and subsequent tank void uses. A figure provides a diagram estimating how the TFF could be used as part of the separations options. Other possible TFF uses are also discussed in this study.

  12. Two satellite study of substorm expansion near geosynchronous orbit

    Directory of Open Access Journals (Sweden)

    Ø. Holter

    2004-12-01

    Full Text Available During several time intervals in 1979–1980 the satellites GEOS-2 and SCATHA were situated relatively close on the nightside of the Earth at geosynchronous distances. Several substorm events were identified during these periods. The event considered in this paper was recorded on 22 May 1979, when the satellites were separated by less than 30min in local time around 21:00 LT. The observed 45 to 60 s delay of magnetic signatures observed at the two s/c indicates a westward expansion of ~7.7°/min. At the two s/c, the magnetic signatures are, in particular for the azimuthal magnetic field components, quite different. At GEOS-2, being close to the magnetic equator, the dominant feature is a dipolarization with a weak field-aligned current signature corresponding to a symmetric current which cancels at the equator. On SCATHA, however, being close to the current sheet boundary, the azimuthal magnetic field indicates a strong field-aligned Birkeland current structure. On both s/c the first indication of an approaching substorm was an increase in the high energy ion flux followed by a reduction in the flux intensity of energetic electrons and a further tailward stretching of the magnetic field, starting ~2min before the onset of the magnetic field dipolarization. The tailward stretching, the observed variations of the magnetic field components, and the subsequent dipolarization are interpreted in terms of an azimuthally tilted field-aligned current system passing the s/c on the tailward side from east to west. The westward expansion and dipolarization observed at the two s/c are consistent with the propagation of a Rayleigh-Taylor type instability. The increased radial ion flux corresponds to the ExB-drift due to the substorm associated electric field.

    Key words. Magnetospheric physics (storms and substorms; plasma waves and instabilities; current systems

  13. Using Enabling Technologies to Facilitate the Comparison of Satellite Observations with the Model Forecasts for Hurricane Study

    Science.gov (United States)

    Li, P.; Knosp, B.; Hristova-Veleva, S. M.; Niamsuwan, N.; Johnson, M. P.; Shen, T. P. J.; Tanelli, S.; Turk, J.; Vu, Q. A.

    2014-12-01

    Due to their complexity and volume, the satellite data are underutilized in today's hurricane research and operations. To better utilize these data, we developed the JPL Tropical Cyclone Information System (TCIS) - an Interactive Data Portal providing fusion between Near-Real-Time satellite observations and model forecasts to facilitate model evaluation and improvement. We have collected satellite observations and model forecasts in the Atlantic Basin and the East Pacific for the hurricane seasons since 2010 and supported the NASA Airborne Campaigns for Hurricane Study such as the Genesis and Rapid Intensification Processes (GRIP) in 2010 and the Hurricane and Severe Storm Sentinel (HS3) from 2012 to 2014. To enable the direct inter-comparisons of the satellite observations and the model forecasts, the TCIS was integrated with the NASA Earth Observing System Simulator Suite (NEOS3) to produce synthetic observations (e.g. simulated passive microwave brightness temperatures) from a number of operational hurricane forecast models (HWRF and GFS). An automated process was developed to trigger NEOS3 simulations via web services given the location and time of satellite observations, monitor the progress of the NEOS3 simulations, display the synthetic observation and ingest them into the TCIS database when they are done. In addition, three analysis tools, the joint PDF analysis of the brightness temperatures, ARCHER for finding the storm-center and the storm organization and the Wave Number Analysis tool for storm asymmetry and morphology analysis were integrated into TCIS to provide statistical and structural analysis on both observed and synthetic data. Interactive tools were built in the TCIS visualization system to allow the spatial and temporal selections of the datasets, the invocation of the tools with user specified parameters, and the display and the delivery of the results. In this presentation, we will describe the key enabling technologies behind the design of

  14. Fuel quality processing study, volume 1

    Science.gov (United States)

    Ohara, J. B.; Bela, A.; Jentz, N. E.; Syverson, H. T.; Klumpe, H. W.; Kessler, R. E.; Kotzot, H. T.; Loran, B. L.

    1981-01-01

    A fuel quality processing study to provide a data base for an intelligent tradeoff between advanced turbine technology and liquid fuel quality, and also, to guide the development of specifications of future synthetic fuels anticipated for use in the time period 1985 to 2000 is given. Four technical performance tests are discussed: on-site pretreating, existing refineries to upgrade fuels, new refineries to upgrade fuels, and data evaluation. The base case refinery is a modern Midwest refinery processing 200,000 BPD of a 60/40 domestic/import petroleum crude mix. The synthetic crudes used for upgrading to marketable products and turbine fuel are shale oil and coal liquids. Of these syncrudes, 50,000 BPD are processed in the existing petroleum refinery, requiring additional process units and reducing petroleum feed, and in a new refinery designed for processing each syncrude to produce gasoline, distillate fuels, resid fuels, and turbine fuel, JPGs and coke. An extensive collection of synfuel properties and upgrading data was prepared for the application of a linear program model to investigate the most economical production slate meeting petroleum product specifications and turbine fuels of various quality grades. Technical and economic projections were developed for 36 scenarios, based on 4 different crude feeds to either modified existing or new refineries operated in 2 different modes to produce 7 differing grades of turbine fuels. A required product selling price of turbine fuel for each processing route was calculated. Procedures and projected economics were developed for on-site treatment of turbine fuel to meet limitations of impurities and emission of pollutants.

  15. Sampling error study for rainfall estimate by satellite using a stochastic model

    Science.gov (United States)

    Shin, Kyung-Sup; North, Gerald R.

    1988-01-01

    In a parameter study of satellite orbits, sampling errors of area-time averaged rain rate due to temporal sampling by satellites were estimated. The sampling characteristics were studied by accounting for the varying visiting intervals and varying fractions of averaging area on each visit as a function of the latitude of the grid box for a range of satellite orbital parameters. The sampling errors were estimated by a simple model based on the first-order Markov process of the time series of area averaged rain rates. For a satellite of nominal Tropical Rainfall Measuring Mission (Thiele, 1987) carrying an ideal scanning microwave radiometer for precipitation measurements, it is found that sampling error would be about 8 to 12 pct of estimated monthly mean rates over a grid box of 5 X 5 degrees. It is suggested that an observation system based on a low inclination satellite combined with a sunsynchronous satellite simultaneously might be the best candidate for making precipitation measurements from space.

  16. Ironmaking Process Alternative Screening Study, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Lockwood Greene, . .

    2005-01-06

    Iron in the United States is largely produced from iron ore mined in the United States or imported from Canada or South America. The iron ore is typically smelted in Blast Furnaces that use primarily iron ore, iron concentrate pellets metallurgical coke, limestone and lime as the raw materials. Under current operating scenarios, the iron produced from these Blast Furnaces is relatively inexpensive as compared to current alternative iron sources, e.g. direct iron reduction, imported pig iron, etc. The primary problem the Blast Furnace Ironmaking approach is that many of these Blast furnaces are relatively small, as compared to the newer, larger Blast Furnaces; thus are relatively costly and inefficient to operate. An additional problem is also that supplies of high-grade metallurgical grade coke are becoming increasingly in short supply and costs are also increasing. In part this is due to the short supply and costs of high-grade metallurgical coals, but also this is due to the increasing necessity for environmental controls for coke production. After year 2003 new regulations for coke product environmental requirement will likely be promulgated. It is likely that this also will either increase the cost of high-quality coke production or will reduce the available domestic U.S. supply. Therefore, iron production in the United States utilizing the current, predominant Blast Furnace process will be more costly and would likely be curtailed due to a coke shortage. Therefore, there is a significant need to develop or extend the economic viability of Alternate Ironmaking Processes to at least partially replace current and declining blast furnace iron sources and to provide incentives for new capacity expansion. The primary conclusions of this comparative Study of Alternative Ironmaking Process scenarios are: (1) The processes with the best combined economics (CAPEX and OPEX impacts in the I.R.R. calculation) can be grouped into those Fine Ore based processes with no scrap

  17. Loss of entorhinal cortex and hippocampal volumes compared to whole brain volume in normal aging: the SMART-Medea study.

    Science.gov (United States)

    Knoops, Arnoud J G; Gerritsen, Lotte; van der Graaf, Yolanda; Mali, Willem P T M; Geerlings, Mirjam I

    2012-07-30

    In non-demented elderly age-related decline in hippocampal volume has often been observed, but it is not clear if this loss is disproportionate relative to other brain tissue. Few studies examined age-related volume loss of the entorhinal cortex. We investigated the association of age with hippocampal and entorhinal cortex (ERC) volumes in a large sample of middle-aged and older persons without dementia. Within the SMART-Medea study, cross-sectional analyses were performed in 453 non-demented subjects (mean age 62±9 years, 81% male) with a history of arterial disease. Hippocampal and ERC volumes were assessed by manual segmentation on three-dimensional fast field-echo sequence T1-weighted magnetic resonance images. Automated segmentation was used to quantify volumes of BV and ICV. Hippocampal and ERC volumes were divided by intracranial volume (ICV) as well as total brain volume (BV) to determine whether age-related differences were disproportionate relative to other brain tissue. Total crude hippocampal volume was 5.96±0.7 ml and total crude ERC volume was 0.34±0.06 ml. Linear regression analyses adjusted for sex showed that with increasing age, hippocampal volume divided by ICV decreased (B per year older=-0.01 ml; 95% CI -0.02 to -0.004). However, no age-related decline in hippocampal volume relative to BV was observed (B per year older=0.005 ml; 95% CI -0.002 to 0.01). No age-related decline in ERC volume relative to ICV or BV was observed. In this population of nondemented patients with a history of vascular disease no age-related decline in entorhinal cortex volume was observed and although hippocampal volume decreased with age, it was not disproportionate relative to total brain volume. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  18. Small power systems study. Volume. Study results. Technical summary report

    Energy Technology Data Exchange (ETDEWEB)

    Sitney, L.R.

    1978-05-31

    The Division of Solar Technology of the Department of Energy is currently examining the market potential of a number of dispersed solar energy systems, including the small (less than or equal to 10 MW/sub e/) solar thermal power system. Small fossil-fueled generating units in the United States utility system, (i.e., investor-owned, municipal, and cooperatives) have a current capacity of approximately 8000 MW/sub e/ or about 1.5 percent of the total US electrical capacity, and provide a large potential market for small solar thermal power systems. The Small Power Systems Study has as its objective the determination of conditions under which small (less than or equal to 10 MW/sub e/) solar thermal power units can provide cost-effective electrical power to a variety of users. Potential users, in addition to the utility systems; include Department of Defense installations and applications, remote mining and/or lumbering operations, and other industrial power systems with and without cogeneration. The first year's results on the Small Power Systems Study are summarized. The data base used and the breakeven cost analysis are discussed. Information on both small (less than or equal to 10 MW/sub e/) generating units and the utility systems using them is presented as well as data on fossil fuel costs, solar plant costs, and solar insolation values. The results of a survey of Department of Defense (DOD) worldwide electrical generating capacity at its military bases and on a potential DOD application are presented. Information on a potential small solar power system experiment in the interior of Alaska is given, and a limited amount of information on a remote application which would provide power or a large open pit copper mine is presented. Volume II of this Technical Summary Report contains an inventory, by state, of the small (less than or equal to 10 MW/sub e/) generating units in the US utility system. (WHK)

  19. Mobile radio alternative systems study satellite/terrestrial (hybrid) systems concepts

    Science.gov (United States)

    Kiesling, J. D.; Anderson, R. E.

    1983-01-01

    The use of satellites for mobile radio service in non-urban areas of the United States in the years from 1985 to 2000 was investigated. Several satellite concepts are considered: a system with single-beam coverage of the fifty United States and Puerto Rico, and multi-beam satellites with greater capacity. All of the needed functions and services identified in the market study are provided by the satellite systems, including nationwide radio access to vehicles without knowledge of vehicle location wideband data transmission from remote sites, two way exchange of short data and control messages between vehicles and dispatch or control centers, and automatic vehicle location (surveillance). The costs of providing the services are within acceptable limits, and the desired returns to the system investors are attractive. The criteria by which the Federal Communication judges the competing demands for public radio spectrum are reviewed with comments on how the criteria might apply to the consideration of land mobile satellites. Institutional arrangements for operating a mobile satellite system are based on the present institutional arrangements in which the services are offered to the end users through wireline and radio common carriers, with direct access by large private and government users.

  20. Multi-satellite rainfall sampling error estimates – a comparative study

    Directory of Open Access Journals (Sweden)

    A. Loew

    2012-10-01

    Full Text Available This study focus is set on quantifying sampling related uncertainty in the satellite rainfall estimates. We conduct observing system simulation experiment to estimate sampling error for various constellations of Low-Earth orbiting and geostationary satellites. There are two types of microwave instruments currently available: cross track sounders and conical scanners. We evaluate the differences in sampling uncertainty for various satellite constellations that carry instruments of the common type as well as in combination with geostationary observations. A precise orbital model is used to simulate realistic satellite overpasses with orbital shifts taken into account. With this model we resampled rain gauge timeseries to simulate satellites rainfall estimates free of retrieval and calibration errors. We concentrate on two regions, Germany and Benin, areas with different precipitation regimes. Our results show that sampling uncertainty for all satellite constellations does not differ greatly depending on the area despite the differences in local precipitation patterns. Addition of 3 hourly geostationary observations provides equal performance improvement in Germany and Benin, reducing rainfall undersampling by 20–25% of the total rainfall amount. Authors do not find a significant difference in rainfall sampling between conical imager and cross-track sounders.

  1. Study of High-Temperature Superconductor Diplexers for Satellite Communications

    Institute of Scientific and Technical Information of China (English)

    LIU Juan-xiu; YANG Kai; LUO Zheng-xiang; BU Shi-rong; NING Jun-song; ZHANG Tian-liang

    2005-01-01

    The high-temperature superconductor (HTSC) resonator and diplexer are simulated by full-wave tools.A newly developed miniature HTSC diplexer is designed and fabricated on double sided YBa2Cu3O7 (YBCO) film (YBCO/LaAlO3/YBCO), the thickness of which is 400 nm for YBCO and 0.5 mm for the LaAlO3. The measured results show a good agreement with the simulation. The volume and mass of the diplexers are greatly reduced by miniaturized configuration.

  2. Preschool and Primary Education. Estonian Studies in Education. Volume 3

    Science.gov (United States)

    Mikk, Jaan, Ed.; Veisson, Marika, Ed.; Luik, Piret, Ed.

    2011-01-01

    The studies in this volume explore a number of issues in education today. One paper reveals what actually motivates teachers to develop their career, another, how to teach primary teachers to talk about visual art. Children's artworks were explored in one article to see how they relate to their adjustment to school. In another, a case study was…

  3. External field characterization using CHAMP satellite data for induction studies

    Indian Academy of Sciences (India)

    Praveen Kunagu; E Chandrasekhar

    2013-06-01

    Knowledge of external inducing source field morphology is essential for precise estimation of electromagnetic (EM) induction response. A better characterization of the external source field of magnetospheric origin can be achieved by decomposing it into outer and inner magnetospheric contributions, which are best represented in Geocentric Solar Magnetospheric (GSM) and Solar Magnetic (SM) reference frames, respectively. Thus we propose a spherical harmonic (SH) model to estimate the outer magnetospheric contribution, following the iterative reweighted least squares approach, using the vector magnetic data of the CHAMP satellite. The data covers almost a complete solar cycle from July 2001 to September 2010, spanning 54,474 orbits. The SH model, developed using orbit-averaged vector magnetic data, reveals the existence of a stable outer magnetospheric contribution of about 7.39 nT. This stable field was removed from the CHAMP data after transforming to SM frame. The residual field in the SM frame acts as a primary source for induction in the Earth. The analysis of this time-series using wavelet transformation showed a dominant 27-day periodicity of the geomagnetic field. Therefore, we calculated the inductive EM -response function in a least squares sense considering the 27-day period variation as the inducing signal. From the estimated -response, we have determined that the global depth to the perfect substitute conductor is about 1132 km and its conductivity is around 1.05 S/m.

  4. Studies of outer planet satellites, Mercury and Uranus

    Science.gov (United States)

    Mckinnon, William B.; Schenk, Paul M.

    1987-01-01

    Arguments were made, based on geometry, for both an impact and an internal origin for the ancient, partially preserved furrow system of Ganymede. It was concluded that furrows were not concentric, but could be impact related if multiringed structures on icy satellites are initially noncircular. The geometry of the Valhalla ring structure on Callisto was examined in order to assess the circularity of an unmodified ring system. The Ganymede furrow system was remapped to make use of improvements in coordinate control. The least-squares center of curvature for all furrows in the Marius and Galileao Regio is -20.7, and 179.2 degrees. Furrows in Marius and Galileo Regio are reasonably concentric, and are much more circular than previously estimated. The perceived present nonalignment of the assumed originally concentric furrows were used to argue for large-scale lateral motion of dark terrain blocks in Ganymede's crust, presumably in association with bright terrain formation., The overall alignment of furrows as well as the inherent scatter in centers of curvature from subregions of Galileo and Marius do not support this hypothesis.

  5. Multibeam Satellite Frequency/Time Duality Study and Capacity Optimization

    CERN Document Server

    Lei, Jiang

    2011-01-01

    In this paper, we investigate two new candidate transmission schemes, Non-Orthogonal Frequency Reuse (NOFR) and Beam-Hoping (BH). They operate in different domains (frequency and time/space, respectively), and we want to know which domain shows overall best performance. We propose a novel formulation of the Signal-to-Interference plus Noise Ratio (SINR) which allows us to prove the frequency/time duality of these schemes. Further, we propose two novel capacity optimization approaches assuming per-beam SINR constraints in order to use the satellite resources (e.g. power and bandwidth) more efficiently. Moreover, we develop a general methodology to include technological constraints due to realistic implementations, and obtain the main factors that prevent the two technologies dual of each other in practice, and formulate the technological gap between them. The Shannon capacity (upper bound) and current state-of-the-art coding and modulations are analyzed in order to quantify the gap and to evaluate the performa...

  6. Experimental Study on Volume Change Indices of Bentonite Soils

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper reports experimental results regarding statically compacted clay specimens to study the volume change behavior of bentonites. The volume change indices such as the coefficients of compressibility, volume compressibility, and consolidation ( i. e.av , mv and cv respectively) and the saturated coefficient of permeability k at different surcharge pressures were determined with the commonly adopted procedures. The swell potentials, swelling pressures, different phases of the swollen specimens were analyzed for the volume change behavior during compression. Experimental results revealed that the swell potential is dependent on the initial dry density, the initial water content and the vertical pressure at which the clay specimens were allowed to swell. The swelling pressure was found to be similar for the specimens with varying water content, showing strong dependency on the initial void ratio. The compression indices ( viz. mv and av) of saturated specimens decreased with an increase in the vertical pressure. About 80% to 90% of the volume change occurred in the primary compression phase under any given vertical pressure. The coefficient of consolidation cv and the saturated coefficient of permeability k decreased with an increase in the vertical pressure.

  7. Morphological study of transpterional-insula approach using volume rendering.

    Science.gov (United States)

    Jia, Linpei; Su, Lue; Sun, Wei; Wang, Lina; Yao, Jihang; Li, Youqiong; Luo, Qi

    2012-11-01

    This study describes the measurements of inferior circular insular sulcus (ICIS) and the shortest distance from ICIS to the temporal horn and determines the position of the incision, which does less harm to the temporal stem in the transpterional-insula approach using volume-rendering technique. Results of the research showed that one-third point over the anterior side of ICIS may be the ideal penetration point during operation. And there is no difference between 2 hemispheres (P ICIS from other Chinese researches demonstrated that volume rendering is a reliable method in insular research that enables mass measurements.

  8. North American Natural Gas Markets: Selected technical studies. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    Huntington, H.G.; Schuler, G.E. [eds.

    1989-04-01

    The Energy Modeling Forum (EMF) was established in 1976 at Stanford University to provide a structural framework within which energy experts, analysts, and policymakers could meet to improve their understanding of critical energy problems. The ninth EMF study, North American Natural Gas Markets, was conducted by a working group comprised of leading natural gas analysts and decision-makers from government, private companies, universities, and research and consulting organizations. The EMF 9 working group met five times from October 1986 through June 1988 to discuss key issues and analyze natural gas markets. This third volume includes technical papers that support many of the conclusions discussed in the EMF 9 summary report (Volume 1) and full working group report (Volume 2). These papers discuss the results from the individual models as well as some nonmodeling analysis related to US natural gas imports and industrial natural gas demand. Individual papers have been processed separately for inclusion in the Energy Science and Technology Database.

  9. Study of LEO-SAT microwave link for broad-band mobile satellite communication system

    Science.gov (United States)

    Fujise, Masayuki; Chujo, Wataru; Chiba, Isamu; Furuhama, Yoji; Kawabata, Kazuaki; Konishi, Yoshihiko

    1993-01-01

    In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented.

  10. TOLNET – A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Directory of Open Access Journals (Sweden)

    Newchurch Michael J.

    2016-01-01

    Full Text Available Ozone lidars measure continuous, high-resolution ozone profiles critical for process studies and for satellite validation in the lower troposphere. However, the effectiveness of lidar validation by using single-station data is limited. Recently, NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly timeresolved (few minutes tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation. This article briefly describes the concept, stations, major specifications of the TOLNet instruments, and data archiving.

  11. A study on quality and availability of COCTS images of HY- 1 satellite by simulation

    Institute of Scientific and Technical Information of China (English)

    李淑菁; 毛天明; 潘德炉

    2002-01-01

    Hy-1 is a first China's ocean color satellite which will be launched as a piggyback satellite on FY- 1 satellite using Long March rocket. On the satellite there are two sensors: one is the China's ocean color and temperature scanner (COCTS), the other is CCD coastal zone imager (CZI).The COCTS is considered to be a main sensor to play a key role. In order to understand the characteristics of future ocean color images observed, a simulation and evaluation study on the quality and availability of the COCTS image has been done. First, the simulation models are introduced briefly, and typical simulated cases of radiance images at visible bands are introduced, in which the radiance distribution is based on geographic location, the satellite orbital parameters and sensor properties, the simulated method to evaluate the image quality and availability is developed by using the characteristics of image called the complex signal noise ratio ( CSNR ). Meanwhile, a series of the CSNR images are generated from the simulated radiance components for different cases, which can be used to evaluate the quality and availability of the COCTS images before the HY - 1 is placed in orbit. Finally, the quality and availability of the COCTS images are quantitatively analyzed with the simulated CSNR data. The results will be beneficial to all scientists who are in charge of the COCTS mission and to those who plan to use the data from the COCTS.

  12. Experimental Study on the Precise Orbit Determination of the BeiDou Navigation Satellite System

    Directory of Open Access Journals (Sweden)

    Jens Wickert

    2013-03-01

    Full Text Available The regional service of the Chinese BeiDou satellite navigation system is now in operation with a constellation including five Geostationary Earth Orbit satellites (GEO, five Inclined Geosynchronous Orbit (IGSO satellites and four Medium Earth Orbit (MEO satellites. Besides the standard positioning service with positioning accuracy of about 10 m, both precise relative positioning and precise point positioning are already demonstrated. As is well known, precise orbit and clock determination is essential in enhancing precise positioning services. To improve the satellite orbits of the BeiDou regional system, we concentrate on the impact of the tracking geometry and the involvement of MEOs, and on the effect of integer ambiguity resolution as well. About seven weeks of data collected at the BeiDou Experimental Test Service (BETS network is employed in this experimental study. Several tracking scenarios are defined, various processing schemata are designed and carried out; and then, the estimates are compared and analyzed in detail. The results show that GEO orbits, especially the along-track component, can be significantly improved by extending the tracking network in China along longitude direction, whereas IGSOs gain more improvement if the tracking network extends in latitude. The involvement of MEOs and ambiguity-fixing also make the orbits better.

  13. Second-generation mobile satellite system. A conceptual design and trade-off study

    Science.gov (United States)

    Sue, M. K.; Park, Y. H.

    1985-01-01

    In recent years, interest has grown in the mobile satellite (MSAT) system, a satellite-based communications system capable of providing integrated voice and data services to a large number of users. To explore the potential of a commercial mobile satellite system (MSS) beyond the horizon of the first generation, using technologies of the 1990's and to assist MSAT-X in directing its efforts, a conceptual design has been performed for a second-generation system to be launched around the mid-1990's. The design goal is to maximize the number of satellite channels and/or minimize the overall life-cycle cost, subject to the constraint of utilizing a commercial satellite bus with minimum modifications. To provide an optimal design, a series of trade-offs are performed, including antenna sizing, feed configurations, and interference analysis. Interference is a serious problem for MSAT and often an overlapping feed design is required to reduce interbeam interference. The trade-off studies will show that a simple non-overlapping feed is sufficient for the second-generation system, thus avoiding the need for the complicated beam-forming network that is associated with the overlapping feed designs. In addition, a system that operates at L-band, an alternative frequency band that is being considered by some for possible MSAT applications, is also presented.

  14. Digital Radio Broadcasting using the mixed satellite/terrestrial approach: An application study

    Science.gov (United States)

    Paiement, Richard V.; Voyer, Rene; Prendergast, Doug

    1995-01-01

    Digital radio broadcasting (DRB) is a new service that offers CD quality stereo programs to fixed, portable and mobile receivers. Terrestrial DRB in Canada is considered as a replacement technology for existing AM and FM services, and it is expected to start up in 1996. Canada currently favors Eureka 147 technology operating in the L-band, in the 1452-1492 MHz frequency band allocated during WARC'92 for DRB. Terrestrial DRB delivery is appropriate for small to medium sized service areas, such as cities and their associated suburbs. For larger areas such as provinces, as well as for sparsely populated areas such as the regions in northern Canada, satellite delivery is more appropriate. The mixed approach is based on both satellite and terrestrial broadcasting services using a common frequency band. Spectrum efficiency is achieved through close coordination of both service types, to achieve proper frequency sharing and spectrum re-use. As well, use of a common transmission format by both types of services allows for a common receiver. This mixed satellite/terrestrial approach to DRB is being seriously considered in Canada and in other countries. This paper studies the feasibility of such a mixed satellite/terrestrial DRB system. It looks at possible coverage scenarios for Canada, and at the satellite and receiver technology requirements.

  15. Study on application potentiality of the first China's ocean satellite HY- 1A

    Institute of Scientific and Technical Information of China (English)

    Pan Delu; He Xianqiang; Li Shujing; Gong Fang

    2003-01-01

    China has launched her first ocean color satellite HY- 1A on May 15, 2002 since American ocean color satellite SeaSTAR was on the orbit in 1997. First, the properties and characteristics of HY - 1A are briefly introduced; second, the quality and availability are evaluated by means of the complex signal noise ratio (CSNR) which is simulated theoretically; third, the received HY- 1A data are compared with SeaSTAR data to understand the accuracy of radiance measurement by the HY- 1A; finally, the remote sensing products of ocean color and temperature are mapped to study the application potentiality of HY- 1A. The results show that the HY- 1A has its latent capability for the application of marine environment detection, the management and protection of marine resources, and the national rights and interests. Meanwhile some suggestions are proposed to modify the next ocean satellite.

  16. Validation of PV performance models using satellite-based irradiance measurements : a case study.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Parkins, Andrew (Clean Power Research); Perez, Richard (University at Albany)

    2010-05-01

    Photovoltaic (PV) system performance models are relied upon to provide accurate predictions of energy production for proposed and existing PV systems under a wide variety of environmental conditions. Ground based meteorological measurements are only available from a relatively small number of locations. In contrast, satellite-based radiation and weather data (e.g., SUNY database) are becoming increasingly available for most locations in North America, Europe, and Asia on a 10 x 10 km grid or better. This paper presents a study of how PV performance model results are affected when satellite-based weather data is used in place of ground-based measurements.

  17. The FODA-TDMA satellite access scheme - Presentation, study of the system, and results

    Science.gov (United States)

    Celandroni, Nedo; Ferro, Erina

    1991-12-01

    A description is given of FODA-TDMA, a satellite access scheme designed for mixed traffic. The study of the system is presented and the choice of some parameters is justified. A simplified analytic solution is found, describing the steady-state behavior of the system. Some results of the simulation tests for an already existing hardware environment are also presented for the channel speeds of 2 and 8 Mb/s, considering both the stationary and the transient cases. The results of the experimentation at 2 Mb/s on the satellite Eutelsat-F2 are also presented and compared with the results of the simulation.

  18. Partial volume effects in dynamic contrast magnetic resonance renal studies

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, D. Rodriguez, E-mail: drodriguez@biotronics3d.co [CVSSP, Faculty of Engineering and Physical Sciences, University of Surrey (United Kingdom); Wells, K., E-mail: k.wells@surrey.ac.u [CVSSP, Faculty of Engineering and Physical Sciences, University of Surrey (United Kingdom); Diaz Montesdeoca, O., E-mail: o.diaz.montesdeoca@gmail.co [EUITT, Universidad de Las Palmas de Gran Canaria (Spain); Moran Santana, A. [EUITT, Universidad de Las Palmas de Gran Canaria (Spain); Mendichovszky, I.A., E-mail: iosifm@hotmail.co [Radiology and Physics Unit, UCL Institute of Child Health, London WC1N 1EH (United Kingdom); Gordon, I., E-mail: i.gordon@ich.ucl.ac.u [Radiology and Physics Unit, UCL Institute of Child Health, London WC1N 1EH (United Kingdom)

    2010-08-15

    This is the first study of partial volume effect in quantifying renal function on dynamic contrast enhanced magnetic resonance imaging. Dynamic image data were acquired for a cohort of 10 healthy volunteers. Following respiratory motion correction, each voxel location was assigned a mixing vector representing the 'overspilling' contributions of each tissue due to the convolution action of the imaging system's point spread function. This was used to recover the true intensities associated with each constituent tissue. Thus, non-renal contributions from liver, spleen and other surrounding tissues could be eliminated from the observed time-intensity curves derived from a typical renal cortical region of interest. This analysis produced a change in the early slope of the renal curve, which subsequently resulted in an enhanced glomerular filtration rate estimate. This effect was consistently observed in a Rutland-Patlak analysis of the time-intensity data: the volunteer cohort produced a partial volume effect corrected mean enhancement of 36% in relative glomerular filtration rate with a mean improvement of 7% in r{sup 2} fitting of the Rutland-Patlak model compared to the same analysis undertaken without partial volume effect correction. This analysis strongly supports the notion that dynamic contrast enhanced magnetic resonance imaging of kidneys is substantially affected by the partial volume effect, and that this is a significant obfuscating factor in subsequent glomerular filtration rate estimation.

  19. Updating Object for GIS Database Information Using High Resolution Satellite Images: a Case Study Zonguldak

    Science.gov (United States)

    Alkan, M.; Arca, D.; Bayik, Ç.; Marangoz, A. M.

    2011-09-01

    Nowadays Geographic Information Systems (GIS) uses Remote Sensing (RS) data for a lot of applications. One of the application areas is the updating of the GIS database using high resolution imagery. In this context high resolution satellite imagery data is very important for many applications areas today's and future. And also, high resolution satellite imagery data will be used in many applications for different purposes. Information systems needs to high resolution imagery data for updating. Updating is very important component for the any of the GIS systems. One of this area will be updated and kept alive GIS database information. High resolution satellite imagery is used with different data base which serve map information via internet and different aims of information systems applications in future topographic and cartographic information systems will very important in our country in this sense use of the satellite images will be unavoidable. In this study explain to how is acquired to satellite images and how is use this images in information systems for object and roads. Firstly, pan-sharpened two of the IKONOS's images have been produced by fusion of high resolution PAN and MS images using PCI Geomatica v9.1 software package. Automatic object extraction has been made using eCognition v4.0.6. On the other hand, these objects have been manually digitized from high resolution images using ArcGIS v9.3. software package. Application section of in this study, satellite images data will be compared each other and GIS objects and road database. It is also determined which data is useful in Geographic Information Systems. Finally, this article explains that integration of remote sensing technology and GIS applications.

  20. Parameter Impact on Sharing Studies Between UAS CNPC Satellite Transmitters and Terrestrial Systems

    Science.gov (United States)

    Kerczewski, Robert J.; Wilson, Jeffrey D.; Bishop, William D.

    2015-01-01

    In order to provide a control and non-payload communication (CNPC) link for civil-use unmanned aircraft systems (UAS) when operating in beyond-line-of-sight (BLOS) conditions, satellite communication links are generally required. The International Civil Aviation Organization (ICAO) has determined that the CNPC link must operate over protected aviation safety spectrum allocations. Although a suitable allocation exists in the 5030-5091 MHz band, no satellites provide operations in this band and none are currently planned. In order to avoid a very lengthy delay in the deployment of UAS in BLOS conditions, it has been proposed to use existing satellites operating in the Fixed Satellite Service (FSS), of which many operate in several spectrum bands. Regulatory actions by the International Telecommunications Union (ITU) are needed to enable such a use on an international basis, and indeed Agenda Item (AI) 1.5 for the 2015 World Radiocommunication Conference (WRC) was established to decide on the enactment of possible regulatory provisions. As part of the preparation for AI 1.5, studies on the sharing FSS bands between existing services and CNPC for UAS are being contributed by NASA and others. These studies evaluate the potential impact of satellite CNPC transmitters operating from UAS on other in-band services, and on the potential impact of other in-band services on satellite CNPC receivers operating on UAS platforms. Such studies are made more complex by the inclusion of what are essentially moving FSS earth stations, compared to typical sharing studies between fixed elements. Hence, the process of determining the appropriate technical parameters for the studies meets with difficulty. In order to enable a sharing study to be completed in a less-than-infinite amount of time, the number of parameters exercised must be greatly limited. Therefore, understanding the impact of various parameter choices is accomplished through selectivity analyses. In the case of sharing

  1. TOLNet - A Tropospheric Ozone Lidar Profiling Network for Satellite Continuity and Process Studies

    Science.gov (United States)

    Newchurch, Michael J.; Kuang, Shi; Wang, Lihua; LeBlanc, Thierry; Alvarez II, Raul J.; Langford, Andrew O.; Senff, Christoph J.; Brown, Steve; Johnson, Bryan; Burris, John F.; hide

    2015-01-01

    NASA initiated an interagency ozone lidar observation network under the name TOLNet to promote cooperative multiple-station ozone-lidar observations to provide highly time-resolved (few minutes) tropospheric-ozone vertical profiles useful for air-quality studies, model evaluation, and satellite validation.

  2. Celebrate with SATELLITES: An International Polar Year Partnership to Study Earth's Materials

    Science.gov (United States)

    Hedley, Mikell Lynne; Czajkowski, Kevin; Struble, Janet; Benko, Terri; Shellito, Brad; Sheridan, Scott; Stasiuk, Mandy Munroe

    2009-01-01

    The SATELLITES program uses geospatial technologies to study surface temperatures of Earth's materials, such as sand, soil, grass, and water. Data are collected using Global Learning and Observations to Benefit the Environment (GLOBE) protocols, which are then used in research projects that are a part of the International Polar Year (IPY).…

  3. A CASE STUDY OF BRAIN VOLUME REDUCTION IN MULTIPLE SCLEROSIS

    Directory of Open Access Journals (Sweden)

    Ivan N. Dimitrov

    2013-07-01

    Full Text Available The development of sophisticated magnetic resonance imaging techniques and software for medical imaging processing and analysis has led to a significant progress in multiple sclerosis research and clinical care. The measurement of brain volumes provides a quantitative representation of damage, thus facilitating the objective follow-up process. The parameters obtained, though not being used routinely in clinical practice, are more and more often applied in clinical studies. The amount of whole brain and regional atrophy, estimated from serial scans, is considered important not only for disease progression, but also for cognitive dysfunction which is common in multiple sclerosis. In this paper we describe a volumetric study of two magnetic resonance scans of a patient with relapsing-remitting multiple sclerosis, performed 16 months one after the other, and analyzed using FSL SIENA software. Analysis demonstrated brain volume reduction of 1.7% between the two scans. We discuss the advantages of the method and its possible clinical applications.

  4. Drug and Alcohol Studies (Volume 4: Policy approaches)

    OpenAIRE

    Macgregor, S.; Thom, B

    2014-01-01

    VOLUME FOUR: POLICY APPROACHES Preface Robert MacCoun and Peter Reuter The Varieties of Drug Control at the Dawn of the 21st Century Comparative Analysis of Alcohol Control Policies in 30 Countries Donald Brand et al A Comparative Study of 38 European Countries Limited Rationality and the Limits of Supply Reduction Jonathan Caulkins and Robert MacCoun The Limited Relevance of Drug Policy Craig Reinerman, Peter Cohen and Hendrien Kaal Cannabis in Amsterdam and San Francisco AIDS and Injecting ...

  5. Integrated Power/Attitude Control System (IPACS) study. Volume 1: Feasibility studies. [application of flywheels for power storage and generation

    Science.gov (United States)

    Notti, J. E.; Cormack, A., III; Schmill, W. C.

    1974-01-01

    An Integrated Power/Attitude Control System (IPACS) concept consisting of an array of spinning flywheels, with or without gimbals, capable of performing the dual function of power storage and generation, as well as attitude control has been investigated. This system provides attitude control through momentum storage, and replaces the storage batteries onboard the spacecraft. The results of the investigation are presented in two volumes. The trade-off studies performed to establish the feasibility, cost effectiveness, required level of development, and boundaries of application of IPACS to a wide variety of spacecraft are discussed. The conceptual designs for a free-flying research application module (RAM), and for a tracking and data relay satellite (TDRS) are presented. Results from dynamic analyses and simulations of the IPACS conceptual designs are included.

  6. Satellite microwave estimates of soil moisture and applications for desertification studies

    Science.gov (United States)

    Owe, Manfred; Van de Griend, Adriaan A.; de Jeu, Richard A.; de Vries, Jorrit; Seyhan, E.

    1998-12-01

    Based on a series of studies conducted in Botswana and preliminary results from an ongoing study in Spain, developments in microwave remote sensing by satellite which can be used to monitor near real-time surface moisture and also study long term soil moisture climatology are described. A progression of methodologies beginning with single polarization studies and leading to both dual polarization and multiple frequency techniques are described. Continuing analysis of a nine year data set of satellite-derived surface moisture in Spain is ongoing. Preliminary results from this study appear to provide some evidence of long term decertification in certain parts of this region. The methodologies developed during these investigations can be applied to other regions, and have the potential for providing modelers with extended data sets of independently derived surface moisture for simulation and validation studies, and climate change studies at the global scale.

  7. Satellite data compression

    CERN Document Server

    Huang, Bormin

    2011-01-01

    Satellite Data Compression covers recent progress in compression techniques for multispectral, hyperspectral and ultra spectral data. A survey of recent advances in the fields of satellite communications, remote sensing and geographical information systems is included. Satellite Data Compression, contributed by leaders in this field, is the first book available on satellite data compression. It covers onboard compression methodology and hardware developments in several space agencies. Case studies are presented on recent advances in satellite data compression techniques via various prediction-

  8. Design optimization studies for large-scale contoured beam deployable satellite antennas

    Science.gov (United States)

    Tanaka, Hiroaki

    2006-05-01

    Satellite communications systems over the past two decades have become more sophisticated and evolved new applications that require much higher flux densities. These new requirements to provide high data rate services to very small user terminals have in turn led to the need for large aperture space antenna systems with higher gain. Conventional parabolic reflectors constructed of metal have become, over time, too massive to support these new missions in a cost effective manner and also have posed problems of fitting within the constrained volume of launch vehicles. Designers of new space antenna systems have thus begun to explore new design options. These design options for advanced space communications networks include such alternatives as inflatable antennas using polyimide materials, antennas constructed of piezo-electric materials, phased array antenna systems (especially in the EHF bands) and deployable antenna systems constructed of wire mesh or cabling systems. This article updates studies being conducted in Japan of such deployable space antenna systems [H. Tanaka, M.C. Natori, Shape control of space antennas consisting of cable networks, Acta Astronautica 55 (2004) 519-527]. In particular, this study shows how the design of such large-scale deployable antenna systems can be optimized based on various factors including the frequency bands to be employed with such innovative reflector design. In particular, this study investigates how contoured beam space antennas can be effective by constructed out of so-called cable networks or mesh-like reflectors. This design can be accomplished via "plane wave synthesis" and by the "force density method" and then to iterate the design to achieve the optimum solution. We have concluded that the best design is achieved by plane wave synthesis. Further, we demonstrate that the nodes on the reflector are best determined by a pseudo-inverse calculation of the matrix that can be interpolated so as to achieve the minimum

  9. Flood Monitoring and Hydrologic Studies Using Retracked Satellite Radar Altimetry

    Science.gov (United States)

    Zhang, M.; Shum, C.; Lee, H.; Alsdorf, D.; Schwartz, F.

    2008-12-01

    Nadir, pulse-limited radar altimetry measurements have been used to monitor large surface-water bodies. In spite of progress, there is a need for a robust and automated procedure, which allows classification and stage measurements in small water bodies, which lying along the orbital path, using multiple radar altimeter measurements. Here we used an algorithm, which is mainly based on radar scatter waveform response and statistical analysis of mean and standard deviation of the resulting water level change to classify surface- waters from other land covers. We tested the algorithm using 10-Hz retracked radar altimetry measurements from TOPEX over regions including the Amazon River basin, the Prairie Pothole Region in North America, and south-western Taiwan. The estimated water-level stages are compared with data from available stage measurements, and altimetry data available from public data centers. We also applied the algorithm to study the 1997 hundred-year Red River flood, and the June 2008 fifty-year flood in the Upper Midwest of the United States. For the1997 flood, it is found that the flooded regions detected by altimetry include the Red River Basin in North Dakota and Minnesota, the Missouri River Basin in North Dakota and South Dakota, the Minnesota River Basin and the Mississippi River Basin in Minnesota and Iowa. The extent of the flood agrees with the USGS record. The observed water height in Grand Forks reaches 6 meters above the normal. The ENVISAT altimetry is shown to be able to track the ebb and recede of the 2008 Iowa City flood. The results of this study could be applied to provide improved accuracy and potentially automated classification of nadir radar altimetry observed small inland water body measurements for hydrologic studies and for flood monitoring.

  10. Channeling, volume reflection, and volume capture study of electrons in a bent silicon crystal

    DEFF Research Database (Denmark)

    Wistisen, T. N.; Uggerhoj, U. I.; Wienands, U.;

    2016-01-01

    We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111) plane in a strongly bent quasimosaic silicon crystal. These phenomena were investigated at...

  11. Studies of oceanic tectonics based on GEOS-3 satellite altimetry

    Science.gov (United States)

    Poehls, K. A.; Kaula, W. M.; Schubert, G.; Sandwell, D.

    1979-01-01

    Using statistical analysis, geoidal admittance (the relationship between the ocean geoid and seafloor topography) obtained from GEOS-3 altimetry was compared to various model admittances. Analysis of several altimetry tracks in the Pacific Ocean demonstrated a low coherence between altimetry and seafloor topography except where the track crosses active or recent tectonic features. However, global statistical studies using the much larger data base of all available gravimetry showed a positive correlation of oceanic gravity with topography. The oceanic lithosphere was modeled by simultaneously inverting surface wave dispersion, topography, and gravity data. Efforts to incorporate geoid data into the inversion showed that the base of the subchannel can be better resolved with geoid rather than gravity data. Thermomechanical models of seafloor spreading taking into account differing plate velocities, heat source distributions, and rock rheologies were discussed.

  12. An Object Model for Integrating Diverse Remote Sensing Satellite Sensors: A Case Study of Union Operation

    Directory of Open Access Journals (Sweden)

    Chuli Hu

    2014-01-01

    Full Text Available In the Earth Observation sensor web environment, the rapid, accurate, and unified discovery of diverse remote sensing satellite sensors, and their association to yield an integrated solution for a comprehensive response to specific emergency tasks pose considerable challenges. In this study, we propose a remote sensing satellite sensor object model, based on the object-oriented paradigm and the Open Geospatial Consortium Sensor Model Language. The proposed model comprises a set of sensor resource objects. Each object consists of identification, state of resource attribute, and resource method. We implement the proposed attribute state description by applying it to different remote sensors. A real application, involving the observation of floods at the Yangtze River in China, is undertaken. Results indicate that the sensor inquirer can accurately discover qualified satellite sensors in an accurate and unified manner. By implementing the proposed union operation among the retrieved sensors, the inquirer can further determine how the selected sensors can collaboratively complete a specific observation requirement. Therefore, the proposed model provides a reliable foundation for sharing and integrating multiple remote sensing satellite sensors and their observations.

  13. a Detailed Study about Digital Surface Model Generation Using High Resolution Satellite Stereo Imagery

    Science.gov (United States)

    Gong, K.; Fritsch, D.

    2016-06-01

    Photogrammetry is currently in a process of renaissance, caused by the development of dense stereo matching algorithms to provide very dense Digital Surface Models (DSMs). Moreover, satellite sensors have improved to provide sub-meter or even better Ground Sampling Distances (GSD) in recent years. Therefore, the generation of DSM from spaceborne stereo imagery becomes a vivid research area. This paper presents a comprehensive study about the DSM generation of high resolution satellite data and proposes several methods to implement the approach. The bias-compensated Rational Polynomial Coefficients (RPCs) Bundle Block Adjustment is applied to image orientation and the rectification of stereo scenes is realized based on the Project-Trajectory-Based Epipolarity (PTE) Model. Very dense DSMs are generated from WorldView-2 satellite stereo imagery using the dense image matching module of the C/C++ library LibTsgm. We carry out various tests to evaluate the quality of generated DSMs regarding robustness and precision. The results have verified that the presented pipeline of DSM generation from high resolution satellite imagery is applicable, reliable and very promising.

  14. A study of nasal cavity volume by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tosa, Yasuyoshi (Showa Univ., Tokyo (Japan). School of Medicine)

    1992-04-01

    The nasal cavity volume in 69 healthy volunteers from 8 to 23 years old (17 males and 52 females) was studied using magnetic resonance imaging (MRI). Merits of MRI such as no radiation exposure, less artifact due to bone and air and measurement of intravascular blood flow; and demerits such as contraindication in users of heart pace-makers or magnetic clips, contraindication in people with claustrophobia and influence of environmental magnetic fields must be considered. A Magunetom M10 (Siemens), a superconduction device with 1.0 Tesla magnetic flux density was used. Enhanced patterns of T[sub 1], and pulse lines were photographed at 600 msec TR (repetition time) and 19 msec TE (echo time) using SE (spin echo) and short SE (spin echo), and 3 or 4 mm slices. Photographs were made of the piriform aperture, choana, superior-middle-inferior concha including the nasal meatus, the frontal sinus, maxillary sinus, cribriform plate, and upper surface of the palate. The line connecting the maximum depression point in the nasal root and the pontomedullary junction was selected by sagittal median section, because this corresponds well with the CM (canthomeatal) line which is useful in CT (computed tomography). The transverse section of the nasal cavity volume was traced by display console with an accessory MRI device and calculated by integration of the slice width. The increase of height and body weight neared a plateau at almost 16 years, whereas increase of nasal cavity volume continued until about 20 years. Pearson's coefficient of correlation and regression line were significant. There were no significant differences in these parameters between male and female groups. Comparatively strong correlation between nasal cavity volume, and age, height and body weight was statistically evident. (author).

  15. Federal Lighting Efficiency Program (FLEP). Volume 1. Study Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    1977-05-06

    The study was conducted to develop a 10-year Federal Lighting Efficiency Program. It consisted of four analytical tasks: conduct a survey of recent lighting research and development;conduct a cost/benefit evaluation of energy-conserving options available as a result of the lighting research; develop a cost-effective Federal Lighting Efficiency Program plan based on the study results; and identify commercialization barriers that may exist that prevent widespread utilization of the energy-conserving options. The results are summarized in this volume. (ERA citation 04:044906)

  16. Assessment studies on the inversion of satellite to satellite electron content to obtain electron density profiles in the ionosphere

    CERN Document Server

    Hochegger, G P

    2000-01-01

    The electron content data, obtained by satellite-to-satellite occultations of radio signals can lead to height profiles of electron density by discrete inversion. Since there is no possibility to verify such profiles by means of other measurements (practically never measurements at the same time and same location) it was necessary to simulate occultation scenarios by means of an ionosphere model to obtain a large number of comparisons sufficient for investigations on a statistical basis. The obtained electron contents were inverted and compared with electron density height profiles, obtained with the same ionospheric model for the occultation point. The differences between these profiles were investigated (difference between the F2-peak maxima, the height of the maxima, the shape of the topside and bottom side ionosphere). Since simulations were done for chosen locations (250 randomly spread on the globe) for every month and every second hour and for two solar activity levels (HSA and LSA), a whole year was '...

  17. Evaluation of Satellite Rainfall Products over NASA's Iowa Flood Studies (IFloodS) Domain

    Science.gov (United States)

    ElSaadani, Mohamed; Quintero, Felipe; Krajewski, Witold F.; Goska, Radoslaw; Seo, Bongchul

    2014-05-01

    Iowa Flood Studies (IFloodS) is a NASA Global Precipitation Measurement (GPM) Mission to provide better understanding of the strengths and limitations of satellite products in the context of hydrologic applications. IFloodS took place in the central to north eastern part of Iowa in Midwestern United States during the months of April-June, 2013. Quantifying the physical characteristics, space/time variability and assessing satellite rainfall retrieval uncertainties at instantaneous to daily time scales are of the main objectives of IFloodS field experiment beside assessing hydrologic predictive skills as a function of space/time scales and discerning the relative roles of rainfall quantities in flood genesis. The errors of rainfall estimation of three satellite rainfall products (TRMM's TMPA 3B42 V7, CPC's CMORPH and CHRS at UCI's PERSIANN) have been characterized in space and time using NCEP Stage IV radar-rainfall product as a benchmark for comparison. The satellite rainfall products used in this study represent 3 hourly, quarter degree, rainfall accumulation. The benchmark rainfall accumulation has an hourly, four kilometers, resolutions in time and space respectively. We also investigate the adequacy of satellite rainfall products as inputs for hydrological modeling. To this end, these products were used as forcing for the Iowa Flood Center (IFC) hydrological model and produced discharge simulations in a high-resolution drainage network. The IFC hydrological model has been validated using radar rainfall product and thus, the hydrological outputs becomes the reference of comparison for the other rainfall products. We evaluated the hydrological performance of the rainfall products at different spatial scales, ranging from 2 to 14,000 square miles using stream discharge information from USGS gauges network. We discuss the adequacy of the rainfall products for flood forecasting at different spatial scales.

  18. Bias adjustment of satellite-based precipitation estimation using gauge observations: A case study in Chile

    Science.gov (United States)

    Yang, Zhongwen; Hsu, Kuolin; Sorooshian, Soroosh; Xu, Xinyi; Braithwaite, Dan; Verbist, Koen M. J.

    2016-04-01

    Satellite-based precipitation estimates (SPEs) are promising alternative precipitation data for climatic and hydrological applications, especially for regions where ground-based observations are limited. However, existing satellite-based rainfall estimations are subject to systematic biases. This study aims to adjust the biases in the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS) rainfall data over Chile, using gauge observations as reference. A novel bias adjustment framework, termed QM-GW, is proposed based on the nonparametric quantile mapping approach and a Gaussian weighting interpolation scheme. The PERSIANN-CCS precipitation estimates (daily, 0.04°×0.04°) over Chile are adjusted for the period of 2009-2014. The historical data (satellite and gauge) for 2009-2013 are used to calibrate the methodology; nonparametric cumulative distribution functions of satellite and gauge observations are estimated at every 1°×1° box region. One year (2014) of gauge data was used for validation. The results show that the biases of the PERSIANN-CCS precipitation data are effectively reduced. The spatial patterns of adjusted satellite rainfall show high consistency to the gauge observations, with reduced root-mean-square errors and mean biases. The systematic biases of the PERSIANN-CCS precipitation time series, at both monthly and daily scales, are removed. The extended validation also verifies that the proposed approach can be applied to adjust SPEs into the future, without further need for ground-based measurements. This study serves as a valuable reference for the bias adjustment of existing SPEs using gauge observations worldwide.

  19. Study of the Nevada Test Site using Landsat satellite imagery

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, P.D. [Georgetown Univ., Washington, DC (United States). Center for Strategic and International Studies

    1993-07-01

    In the period covered by the purchase order CSIS has obtained one Landsat image and determined that two images previously supplied to the principal investigator under a subcontract with George Washington University were inherently defective. We have negotiated with EOSAT over the reprocessing of those scenes and anticipate final delivery within the next few weeks. A critical early purchase during the subcontract period was of an EXABYTE tape drive, Adaptec SCSI interface, and the appropriate software with which to read Landsat images at CSIS. This gives us the capability of reading and manipulating imagery in house without reliance on outside services which have not proven satisfactory. In addition to obtaining imagery for the study, we have also performed considerable analytic work on the newly and previously purchased images. A technique developed under an earlier subcontract for identifying underground nuclear tests at Pahute Mesa has been significantly refined, and similar techniques were applied to the summit of Rainier Mesa and to the Yucca Flats area. An entirely new technique for enhancing the spectral signatures of different regions of NTS was recently developed, and appears to have great promise of success.

  20. Simulation Studies of Satellite Laser CO2 Mission Concepts

    Science.gov (United States)

    Kawa, Stephan Randy; Mao, J.; Abshire, J. B.; Collatz, G. J.; Sun X.; Weaver, C. J.

    2011-01-01

    Results of mission simulation studies are presented for a laser-based atmospheric CO2 sounder. The simulations are based on real-time carbon cycle process modeling and data analysis. The mission concept corresponds to ASCENDS as recommended by the US National Academy of Sciences Decadal Survey. Compared to passive sensors, active (lidar) sensing of CO2 from space has several potentially significant advantages that hold promise to advance CO2 measurement capability in the next decade. Although the precision and accuracy requirements remain at unprecedented levels of stringency, analysis of possible instrument technology indicates that such sensors are more than feasible. Radiative transfer model calculations, an instrument model with representative errors, and a simple retrieval approach complete the cycle from "nature" run to "pseudodata" CO2. Several mission and instrument configuration options are examined, and the sensitivity to key design variables is shown. Examples are also shown of how the resulting pseudo-measurements might be used to address key carbon cycle science questions.

  1. Satellite Constellations for Space Weather and Ionospheric Studies: Overview of the COSMIC and COSMIC-2 Missions

    Science.gov (United States)

    Schreiner, W. S.; Pedatella, N. M.; Weiss, J.

    2016-12-01

    Measurements from constellations of low Earth orbiting (LEO) satellites are proving highly useful for ionospheric science and space weather studies. The Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC), a joint US/Taiwan mission launched in April 2006, is a six micro-satellite constellation carrying Global Positioning System (GPS) radio occultation (RO) receivers. COSMIC has collected a large amount of useful data from these scientific payloads and is still currently collecting up to 1,000 RO measurement events per day on average. The GPS RO dual-frequency L-band phase and amplitude measurements can be used to observe absolute Total Electron Content (TEC) and scintillation on lines of sight between the LEO and GPS satellites, and electron density profiles via the RO method. The large number and complete global and local time coverage of COSMIC data are allowing scientists to observe ionospheric and plasmaspheric phenomena that are difficult to see with other instruments. The success of COSMIC has prompted U.S. agencies and Taiwan to execute a COSMIC follow-on mission (called COSMIC-2) that will put twelve satellites with GNSS (Global Navigation Satellite System) RO payloads into orbit on two launches in the 2017-20 time frame. The first launch in 2017 will place six satellites in a 520-km altitude 24 deg inclination orbit, which is ideal for low latitude ionospheric research and space weather forecasting. The planned second launch (not currently funded) places six additional satellites in a 750 km 72 deg inclination orbit to provide global coverage and increased sampling density. COSMIC-2 will make use of an advanced radio occultation receiver with an innovative beam-forming antenna design, and is expected to produce at least 10,000 high-quality atmospheric and ionospheric profiles per day from GPS and GLONASS signals to support operational weather prediction, climate monitoring, and space weather forecasting. Each COSMIC-2 spacecraft

  2. NASA Satellite Observations: A Unique Asset for the Study of the Environment and Implications for Public Health

    Science.gov (United States)

    Estes Sue M.

    2010-01-01

    This slide presentation highlights how satellite observation systems are assets for studying the environment in relation to public health. It includes information on current and future satellite observation systems, NASA's public health and safety research, surveillance projects, and NASA's public health partners.

  3. A satellite born charged particles telescope for the study of cosmic ray nuclei

    Energy Technology Data Exchange (ETDEWEB)

    De Pascale, M.P. [Rome Univ. `Tor Vergata` (Italy)]|[INFN, Rome (Italy); Bocciolini, M. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Barbiellini, G.; Boezio, M. [Trieste Univ. (Italy)]|[INFN, Trieste (Italy); Bellotti, R.; Cafagna, F. [Bari Univ. (Italy)]|[INFN, Bari (Italy)

    1995-09-01

    The description of the high energy particle telescope NINA for the study of cosmic ray nuclei is presented. The instrument will be installed on board of the Resource 01 satellite and will fly on a polar orbit at 690 Km. The telescope consists on a pile of 16 detecting planes each of them is composed by two silicon strip detectors with perpendicular strips and has a total area of 60x60mm{sup 2}. The experiment goals are the study of cosmic ray protons and nuclei in the energy range 12-100 MeV/amu. It will be sensitive to the anomalous component and will also make the observation of the large solar flare events and geophysical phenomena as well. This experiment is the first step of the program RIM whose goal is the satellite study of anti particles in primary cosmic rays.

  4. Repetitively Pulsed Electric Laser Acoustic Studies. Volume 1.

    Science.gov (United States)

    1983-09-01

    INGARD ET AL. SEP 83 UNCLASSIFIED APHAL-IR-83-2858-VOL-1 F336i5 86-C 2848 F/ 0/ 8, EEEmohEEEomhiE EohEEmhohEEEEE mhhhmmomhhlm...TR-83-2058, Vol 9, 0 REPETITIVELY PULSED ELECTRIC LASER ACOUSTIC STUDIES Volume I K. U. INGARD , CHARLES F. MCMILLAN uDEPARTMENT OF AERONAUTICS AND...CONTRACT OR GRANT NUMBER(s) K.U. Ingard and Charles F. McMillan F33615.80-C-2040 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT

  5. Reusable Reentry Satellite (RRS) system design study. Phase B, appendix E: Attitude control system study

    Science.gov (United States)

    1991-01-01

    A study which consisted of a series of design analyses for an Attitude Control System (ACS) to be incorporated into the Re-usable Re-entry Satellite (RRS) was performed. The main thrust of the study was associated with defining the control laws and estimating the mass and power requirements of the ACS needed to meet the specified performance goals. The analyses concentrated on the different on-orbit control modes which start immediately after the separation of the RRS from the launch vehicle. The three distinct on-orbit modes considered for these analyses are as follows: (1) Mode 1 - A Gravity Gradient (GG) three-axis stabilized spacecraft with active magnetic control; (2) Mode 2 - A GG stabilized mode with a controlled yaw rotation rate ('rotisserie') using three-axis magnetic control and also incorporating a 10 N-m-s momentum wheel along the (Z) yaw axis; and (3) Mode 3 - A spin stabilized mode of operation with the spin about the pitch (Y) axis, incorporating a 20 N-m-s momentum wheel along the pitch (Y) axis and attitude control via thrusters. To investigate the capabilities of the different controllers in these various operational modes, a series of computer simulations and trade-off analyses have been made to evaluate the achievable performance levels, and the necessary mass and power requirements.

  6. Volumizing effects of a smooth, highly cohesive, viscous 20-mg/mL hyaluronic acid volumizing filler: prospective European study

    Directory of Open Access Journals (Sweden)

    Hoffmann Klaus

    2009-08-01

    Full Text Available Abstract Background Facial volume loss contributes significantly to facial aging. The 20-mg/mL hyaluronic acid (HA formulation used in this study is a smooth, highly cohesive, viscous, fully reversible, volumizing filler indicated to restore facial volume. This first prospective study evaluated use in current aesthetic clinical practice. Methods A pan-European evaluation conducted under guidelines of the World Association of Opinion and Marketing Research, the trial comprised a baseline visit (visit 1 and a follow-up (visit 2 at 14 ± 7 days posttreatment. Physicians photographed patients at each visit. Each patient was treated with the 20-mg/mL HA volumizing filler as supplied in standard packaging. Procedural details, aesthetic outcomes, safety, and physician and patient ratings of their experience were recorded. Results Fifteen physicians and 70 patients (91% female; mean age: 50 years participated. Mean volume loss at baseline was 3.7 (moderate on the Facial Volume Loss Scale. Local anesthesia was used in 64.3% of cases. Most injections (85% were administered with needles rather than cannulas. Of the 208 injections, 59% were in the malar region, primarily above the periosteum. Subcutaneous injections were most common for other sites. The mean total injection volume per patient was 4.6 mL. The mean volume loss score declined significantly (P Conclusion The 20-mg/mL smooth, highly cohesive, viscous, volumizing HA filler was effective, well tolerated, and easy to use in current clinical practice. Participants were very likely to recommend this product to colleagues and friends, and patients would be very or quite likely to request this product for future treatments.

  7. Solar power satellite rectenna design study: Directional receiving elements and parallel-series combining analysis

    Science.gov (United States)

    Gutmann, R. J.; Borrego, J. M.

    1978-01-01

    Rectenna conversion efficiencies (RF to dc) approximating 85 percent were demonstrated on a small scale, clearly indicating the feasibility and potential of efficiency of microwave power to dc. The overall cost estimates of the solar power satellite indicate that the baseline rectenna subsystem will be between 25 to 40 percent of the system cost. The directional receiving elements and element extensions were studied, along with power combining evaluation and evaluation extensions.

  8. PET functional volume delineation: a robustness and repeatability study

    Energy Technology Data Exchange (ETDEWEB)

    Hatt, Mathieu [CHU Morvan, INSERM, U650, LaTIM, Brest (France); CHU MORVAN, LaTIM, INSERM U650, Brest (France); Cheze-le Rest, Catherine [CHU Morvan, INSERM, U650, LaTIM, Brest (France); CHU, Academic Department of Nuclear Medicine, Brest (France); Albarghach, Nidal; Pradier, Olivier [CHU Morvan, INSERM, U650, LaTIM, Brest (France); CHU, Institute of Oncology, Brest (France); Visvikis, Dimitris [CHU Morvan, INSERM, U650, LaTIM, Brest (France)

    2011-04-15

    Current state-of-the-art algorithms for functional uptake volume segmentation in PET imaging consist of threshold-based approaches, whose parameters often require specific optimization for a given scanner and associated reconstruction algorithms. Different advanced image segmentation approaches previously proposed and extensively validated, such as among others fuzzy C-means (FCM) clustering, or fuzzy locally adaptive bayesian (FLAB) algorithm have the potential to improve the robustness of functional uptake volume measurements. The objective of this study was to investigate robustness and repeatability with respect to various scanner models, reconstruction algorithms and acquisition conditions. Robustness was evaluated using a series of IEC phantom acquisitions carried out on different PET/CT scanners (Philips Gemini and Gemini Time-of-Flight, Siemens Biograph and GE Discovery LS) with their associated reconstruction algorithms (RAMLA, TF MLEM, OSEM). A range of acquisition parameters (contrast, duration) and reconstruction parameters (voxel size) were considered for each scanner model, and the repeatability of each method was evaluated on simulated and clinical tumours and compared to manual delineation. For all the scanner models, acquisition parameters and reconstruction algorithms considered, the FLAB algorithm demonstrated higher robustness in delineation of the spheres with low mean errors (10%) and variability (5%), with respect to threshold-based methodologies and FCM. The repeatability provided by all segmentation algorithms considered was very high with a negligible variability of <5% in comparison to that associated with manual delineation (5-35%). The use of advanced image segmentation algorithms may not only allow high accuracy as previously demonstrated, but also provide a robust and repeatable tool to aid physicians as an initial guess in determining functional volumes in PET. (orig.)

  9. An Experimental Biotelemetric Study Based on Satellite Tracking During Post-nesting Migrations of Green Turtles

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A biotelemetry experiment is conducted to study the migrant behavior of green turtles (Chelonia mydas) in South China Sea and acquire the physical environment data. The method in use is to track the post-nesting migrant routes of green turtles through the satellite linked transmitters attached on the back of turtles and the global satellite signal transmitting system of Argos. We obtained the posinestions of the post-nesting migrant routes of three green turtles and environment data, which are important in conservation of green turtles and the research of physical oceanography. Based on the test, the concept, principle and method of biotelemetry are also introduced in this paper with a discussion of the further development of this technique and its applying prospection in future.

  10. Rocket injector anomalies study. Volume 2: Results of parametric studies

    Science.gov (United States)

    Przekwas, A. J.; Singhal, A. K.; Tam, L. T.

    1984-01-01

    The employment of a existing computer program to simulate three dimensional two phase gas spray flows in liquid propellant rocket engines. This was accomplished by modification of an existing three dimensional computer program (REFLAN3D) with Euler/Lagrange approach for simulating two phase spray flow, evaporation and combustion. The modified code is referred to as REFLAN3D-SPRAY. Computational studies of the model rocket engine combustion chamber are presented. The parametric studies of the two phase flow and combustion shows qualitatively correct response for variations in geometrical and physical parameters. The injection nonuniformity test with blocked central fuel injector holes shows significant changes in the central flame core and minor influence on the wall heat transfer fluxes.

  11. How can present and future satellite missions support scientific studies that address ocean acidification?

    Science.gov (United States)

    Salisbury, Joseph; Vandemark, Douglas; Jonsson, Bror; Balch, William; Chakraborty, Sumit; Lohrenz, Steven; Chapron, Bertrand; Hales, Burke; Mannino, Antonio; Mathis, Jeremy T.; Reul, Nicolas; Signorini, Sergio; Wanninkhof, Rik; Yates, Kimberly K.

    2016-01-01

    Space-based observations offer unique capabilities for studying spatial and temporal dynamics of the upper ocean inorganic carbon cycle and, in turn, supporting research tied to ocean acidification (OA). Satellite sensors measuring sea surface temperature, color, salinity, wind, waves, currents, and sea level enable a fuller understanding of a range of physical, chemical, and biological phenomena that drive regional OA dynamics as well as the potentially varied impacts of carbon cycle change on a broad range of ecosystems. Here, we update and expand on previous work that addresses the benefits of space-based assets for OA and carbonate system studies. Carbonate chemistry and the key processes controlling surface ocean OA variability are reviewed. Synthesis of present satellite data streams and their utility in this arena are discussed, as are opportunities on the horizon for using new satellite sensors with increased spectral, temporal, and/or spatial resolution. We outline applications that include the ability to track the biochemically dynamic nature of water masses, to map coral reefs at higher resolution, to discern functional phytoplankton groups and their relationships to acid perturbations, and to track processes that contribute to acid variation near the land-ocean interface.

  12. Satellite remote sensing of Asian aerosols: a case study of clean, polluted and dust storm days

    Directory of Open Access Journals (Sweden)

    K. H. Lee

    2010-06-01

    Full Text Available Satellite-based aerosol observation is a useful tool for the estimation of microphysical and optical characteristics of aerosol during more than three decades. Until now, a lot of satellite remote sensing techniques have been developed for aerosol detection. In East Asian region, the role of satellite observation is quite important because aerosols originating from natural and man-made pollution in this region have been recognized as an important source for regional and global scale air pollution. However, it is still difficult to retrieve aerosol over land because of the complexity of the surface reflection and complex aerosol composition, in particular, aerosol absorption. In this study, aerosol retrievals using Look-up Table (LUT based method was applied to MODerate Resolution Imaging Spectroradiometer (MODIS Level 1 (L1 calibrated reflectance data to retrieve aerosol optical thickness (AOT over East Asia. Three case studies show how the methodology works to identify those differences to obtain a better AOT retrieval. The comparison between the MODIS and Aerosol Robotic Network (AERONET shows better results when the suggested methodology using the cluster based LUTs is applied (linear slope=0.94, R=0.92 than when operational MODIS aerosol products are used (linear slope=0.78, R=0.87. In conclusion, the suggested methodology is shown to work well with aerosol models acquired by statistical clustering the observation data in East Asia.

  13. Channeling, volume reflection, and volume capture study of electrons in a bent silicon crystal

    Science.gov (United States)

    Wistisen, T. N.; Uggerhøj, U. I.; Wienands, U.; Markiewicz, T. W.; Noble, R. J.; Benson, B. C.; Smith, T.; Bagli, E.; Bandiera, L.; Germogli, G.; Guidi, V.; Mazzolari, A.; Holtzapple, R.; Tucker, S.

    2016-07-01

    We present the experimental data and analysis of experiments conducted at SLAC National Accelerator Laboratory investigating the processes of channeling, volume-reflection and volume-capture along the (111) plane in a strongly bent quasimosaic silicon crystal. These phenomena were investigated at 5 energies: 3.35, 4.2, 6.3, 10.5, and 14.0 GeV with a crystal with bending radius of 0.15 m, corresponding to curvatures of 0.053, 0.066, 0.099, 0.16, and 0.22 times the critical curvature, respectively. Based on the parameters of fitting functions we have extracted important parameters describing the channeling process such as the dechanneling length, the angle of volume reflection, the surface transmission, and the widths of the distribution of channeled particles parallel and orthogonal to the plane.

  14. A case study in carbon management during the design process Satellite 3, Stansted Airport, UK

    Institute of Scientific and Technical Information of China (English)

    PeterSHARRATT; CamiloDIAZ

    2003-01-01

    Set within the context of China''s growing need to develop a cleaner and more efficient energy supply infrastructure, this paper describes a procurement process for evaluating and reducing the carbon dioxide emissions arising from operational processes within buildings during the design stage when key decisions affecting long-term energy demand are often made but frequently not understood. The focus of the study is a case-study building, the 8275m2 two-storey arrivals/departures building, Satellite 3, at Stansted Airport, UK. The client set a challenging design performance target of a 20% net CO2 reduction below British Airways Authority''s (BAA) current most energy efficient building, Satellite 1, Stansted. This reduction was to be achieved without compromising the BAA corporate standards on passenger and staff comfort perceptions or appreciable increases in capital costs. The carbon assessment methodology involved the following stages:· Establish baseline CO2 footprint and target from real-time energy data for Satellite 1 of 103 kg CO2/m2/a.· Review of the ‘base-case'' building performance assessment for Satellite 3 using BAA''s standard specification criteria.· Assess the impact on energy demand and CO2 emissions of a number of variations to the ‘base-case'' design parameters ranging from solar shading, insulation levels to control systems and occupancy patterns.· Develop an evaluation methodology that iteratively balances capital cost and revenue expenditure with environmental benefits to enable informed choices to be made by the client on where the most ‘environmentally effective'' design responses lie. Outcomes:· A 23% net CO2 reduction by design was achieved at no additional capital cost.· Learning and environmental costs benefit methodology disseminated to the BAA supply chain and adopted at Gatwick and Heathrow Airports. ·CO2 is now a new key performance indicator for design efficiency within BAA.

  15. Space Station needs, attributes and architectural options. Volume 2, book 1, part 3: Manned Space Station relevance to commercial telecommunications satellites

    Science.gov (United States)

    1983-01-01

    A document containing a forecast of satellite traffic and revelant technology trends to the year 2000 was prepared which includes those space station capabilities and characteristics that should be provided to make the station useful to commercial satellite owners. The document was circulated to key representative organizations within the commercial telecommunications satellite and related communities of interest, including spacecraft manufacturers, commercial satellite owners, communications carriers, networks and risk insurers. The prospectus document is presented as well as the transmittal letter and the mailing list of the people and companies that were asked to review it. Key commercial telecommunications comments are summarized the actual response letters from the industry are included.

  16. Scram discharge volume break studies accident sequence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, R.M.; Hodge, S.A.

    1982-01-01

    This paper is a summary of a report describing the predicted response of Unit 1 at the Tennessee Valley Authority (TVA) Browns Ferry Nuclear Plant to a hypothetical small break loss of coolant accident (SBLOCA) outside of containment. The accident studied would be initiated by a break in the scram discharge volume (SDV) piping when it is pressurized to full reactor vessel pressure as a normal consequence of a reactor scram. If the scram could be reset, the scram outlet valves would close to isolate the SDV and the piping break from the reactor vessel. However, reset is possible only if the conditions that caused the scram have cleared; it has been assumed in this study that the scram signal remains in effect over a long period of time.

  17. Study on TT&C resources scheduling technique based on inter-satellite link

    Science.gov (United States)

    Gu, Xiaosong; Bai, Jian; Zhang, Chunze; Gao, Huili

    2014-11-01

    The navigation constellation will have the capability of supporting Tracking Telemetry and Command (TT&C) operations by inter-satellite link (ISL). The ISL will become an important solution to reduce the shortage of ground TT&C resources. The problems need to be studied urgently in the field of space TT&C network resources scheduling management are how to determine the availability of ISL and how to allocate TT&C resources of ISL. The performance and scheduling constraints of navigation constellation's ISL are analyzed, and three utilization strategies of ISL to perform TT&C operations are proposed. The allocation of TT&C resources based on ISL falls into two successive phases. Firstly, master satellite determination equation is established by using 0-1 Programming model based on the availability matrix. Mathematical method is used to solve the equation to determine the master satellite and the topology of ISL. Secondly, Constraint Programming (CP) model is used to describe the ground TT&C resources scheduling problem with special requirements of TT&C operations based on master satellite, and a heuristic algorithm is designed to solve the CP model. The equations and algorithm are verified by simulation examples. The algorithm of TT&C resources scheduling based on ISL has realized the synthesized usage of both the ISL and ground resources on TT&C field. This algorithm can improve TT&C supports of territorial ground TT&C network for global navigation constellation, and provides technical reference for the TT&C mission planning of global constellation by using ISL.

  18. Cyber security with radio frequency interferences mitigation study for satellite systems

    Science.gov (United States)

    Wang, Gang; Wei, Sixiao; Chen, Genshe; Tian, Xin; Shen, Dan; Pham, Khanh; Nguyen, Tien M.; Blasch, Erik

    2016-05-01

    Satellite systems including the Global Navigation Satellite System (GNSS) and the satellite communications (SATCOM) system provide great convenience and utility to human life including emergency response, wide area efficient communications, and effective transportation. Elements of satellite systems incorporate technologies such as navigation with the global positioning system (GPS), satellite digital video broadcasting, and information transmission with a very small aperture terminal (VSAT), etc. The satellite systems importance is growing in prominence with end users' requirement for globally high data rate transmissions; the cost reduction of launching satellites; development of smaller sized satellites including cubesat, nanosat, picosat, and femtosat; and integrating internet services with satellite networks. However, with the promising benefits, challenges remain to fully develop secure and robust satellite systems with pervasive computing and communications. In this paper, we investigate both cyber security and radio frequency (RF) interferences mitigation for satellite systems, and demonstrate that they are not isolated. The action space for both cyber security and RF interferences are firstly summarized for satellite systems, based on which the mitigation schemes for both cyber security and RF interferences are given. A multi-layered satellite systems structure is provided with cross-layer design considering multi-path routing and channel coding, to provide great security and diversity gains for secure and robust satellite systems.

  19. Literacy & Numeracy Studies Volume 15 No 2 Editorial

    Directory of Open Access Journals (Sweden)

    Alison Lee

    2007-06-01

    Full Text Available This issue of Literacy and Numeracy Studies takes up two major themes shaping the landscape of research and practice in adult literacy. The first of these is the more recent of the two: the intersections between literacy and professional and workplace practice. The second is perhaps a more sustained and enduring concern in the field with the relationship of literacy to context, place and culture. In this sense, this issue of the journal is an expression of the reach and diversity of concerns with literacy in ‘social participation, the utilisation of social resources and the quality of life’ (Green, Lo Bianco and Wyn, this volume and carries forward critical debates for the field across the span of practice from the workplace, to the classroom to the community.

  20. Recent studies in satellite observations of three-dimensional magnetic reconnection

    Institute of Scientific and Technical Information of China (English)

    XIAO ChiJie; WANG XiaoGang; PU ZuYin; MA ZhiWei; ZHAO Hui; ZHOU GuiPing; WANG JingXiu; LIU ZhenXing

    2007-01-01

    Magnetic reconnection is a main process converting the magnetic energy into thermal and kinetic energy in plasmas. It is one of the fundamental problems of crucial importance not only to space plasmas physics and space weather studies,such as the solar flare, coronal mass ejections and magnetospheric substorms, but also to the stability analysis in magnetically confined fusion. In general, except for cases with periodical boundary conditions, three-dimensional (3D) magnetic reconnection occurs on magnetic separatrices generated by magnetic nulls. Here we briefly introduce/review the theories and some recent satellite observations of 3D magnetic reconnection. Topics to be further studied are also discussed.

  1. Monitoring soil wetness variations by means of satellite passive microwave observations: the HYDROPTIMET study cases

    Directory of Open Access Journals (Sweden)

    T. Lacava

    2005-01-01

    Full Text Available Soil moisture is an important component of the hydrological cycle. In the framework of modern flood warning systems, the knowledge of soil moisture is crucial, due to the influence on the soil response in terms of infiltration-runoff. Precipitation-runoff processes, in fact, are related to catchment's hydrological conditions before the precipitation. Thus, an estimation of these conditions is of significant importance to improve the reliability of flood warning systems. Combining such information with other weather-related satellite products (i.e. rain rate estimation might represent a useful exercise in order to improve our capability to handle (and possibly mitigate or prevent hydro-geological hazards. Remote sensing, in the last few years, has supported several techniques for soil moisture/wetness monitoring. Most of the satellite-based techniques use microwave data, thanks to the all-weather and all-time capability of these data, as well as to their high sensitivity to water content in the soil. On the other hand, microwave data are unfortunately highly affected by the presence of surface roughness or vegetation coverage within the instantaneous satellite field of view (IFOV. Those problems, consequently, strongly limit the efficiency and the reliability of traditional satellite techniques. Recently, using data coming from AMSU (Advanced Microwave Sounding Unit, flying aboard NOAA (National Oceanic and Atmospheric Administration satellites, a new methodology for soil wetness estimation has been proposed. The proposed index, called Soil Wetness Variation Index (SWVI, developed by a multi-temporal analysis of AMSU records, seems able to reduce the problems related to vegetation and/or roughness effects. Such an approach has been tested, with promising results, on the analysis of some flooding events which occurred in Europe in the past. In this study, results achieved for the HYDROPTIMET test cases will be analysed and discussed in detail

  2. Studies in Mathematics Education: The Teaching of Statistics, Volume 7.

    Science.gov (United States)

    Morris, Robert, Ed.

    This volume examines the teaching of statistics in the whole range of education, but concentrates on primary and secondary schools. It is based upon selected topics from the Second International Congress on Teaching Statistics (ICOTS 2), convened in Canada in August 1986. The contents of this volume divide broadly into four parts: statistics in…

  3. Quantifying offshore wind resources from satellite wind maps: Study area the North Sea

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Barthelmie, Rebecca Jane; Christiansen, Merete B.;

    2006-01-01

    Offshore wind resources are quantified from satellite synthetic aperture radar (SAR) and satellite scatterometer observations at local and regional scale respectively at the Horns Rev site in Denmark. The method for wind resource estimation from satellite observations interfaces with the wind atl...

  4. A Model To Address Design Constraints of Training Delivered via Satellite. Study Number Eight.

    Science.gov (United States)

    Montler, Joseph; Geroy, Gary D.

    This document: summarizes how some companies are addressing the design constraints involved in using satellite technology to deliver training, presents a model aimed at examining cost effectiveness of the satellite option, and includes a guide to designing instructional materials for delivery by satellite. A survey of 39 organizations, 12…

  5. A Study on the Potential Applications of Satellite Data in Air Quality Monitoring and Forecasting

    Science.gov (United States)

    Li, Can; Hsu, N. Christina; Tsay, Si-Chee

    2011-01-01

    In this study we explore the potential applications of MODIS (Moderate Resolution Imaging Spectroradiometer) -like satellite sensors in air quality research for some Asian regions. The MODIS aerosol optical thickness (AOT), NCEP global reanalysis meteorological data, and daily surface PM(sub 10) concentrations over China and Thailand from 2001 to 2009 were analyzed using simple and multiple regression models. The AOT-PM(sub 10) correlation demonstrates substantial seasonal and regional difference, likely reflecting variations in aerosol composition and atmospheric conditions, Meteorological factors, particularly relative humidity, were found to influence the AOT-PM(sub 10) relationship. Their inclusion in regression models leads to more accurate assessment of PM(sub 10) from space borne observations. We further introduced a simple method for employing the satellite data to empirically forecast surface particulate pollution, In general, AOT from the previous day (day 0) is used as a predicator variable, along with the forecasted meteorology for the following day (day 1), to predict the PM(sub 10) level for day 1. The contribution of regional transport is represented by backward trajectories combined with AOT. This method was evaluated through PM(sub 10) hindcasts for 2008-2009, using ohservations from 2005 to 2007 as a training data set to obtain model coefficients. For five big Chinese cities, over 50% of the hindcasts have percentage error less than or equal to 30%. Similar performance was achieved for cities in northern Thailand. The MODIS AOT data are responsible for at least part of the demonstrated forecasting skill. This method can be easily adapted for other regions, but is probably most useful for those having sparse ground monitoring networks or no access to sophisticated deterministic models. We also highlight several existing issues, including some inherent to a regression-based approach as exemplified by a case study for Beijing, Further studies will be

  6. Study of land surface temperature and spectral emissivity using multi-sensor satellite data

    Indian Academy of Sciences (India)

    P K Srivastava; T J Majumdar; Amit K Bhattacharya

    2010-02-01

    In this study, an attempt has been made to estimate land surface temperatures (LST) and spectral emissivities over a hard rock terrain using multi-sensor satellite data. The study area, of about 6000 km2, is a part of Singhbhum–Orissa craton situated in the eastern part of India. TIR data from ASTER, MODIS and Landsat ETM+ have been used in the present study. Telatemp Model AG-42D Portable Infrared Thermometer was used for ground measurements to validate the results derived from satellite (MODIS/ASTER) data. LSTs derived using Landsat ETM+ data of two different dates have been compared with the satellite data (ASTER and MODIS) of those two dates. Various techniques, viz., temperature and emissivity separation (TES) algorithm, gray body adjustment approach in TES algorithm, Split-Window algorithms and Single Channel algorithm along with NDVI based emissivity approach have been used. LSTs derived from bands 31 and 32 of MODIS data using Split-Window algorithms with higher viewing angle (50°) (LST1 and LST2) are found to have closer agreement with ground temperature measurements (ground LST) over waterbody, Dalma forest and Simlipal forest, than that derived from ASTER data (TES with AST 13). However, over agriculture land, there is some uncertainty and difference between the measured and the estimated LSTs for both validation dates for all the derived LSTs. LST obtained using Single Channel algorithm with NDVI based emissivity method in channel 13 of ASTER data has yielded closer agreement with ground measurements recorded over vegetation and mixed lands of low spectral contrast. LST results obtained with TIR band 6 of Landsat ETM+ using Single Channel algorithm show close agreement over Dalma forest, Simlipal forest and waterbody with LSTs obtained using MODIS and ASTER data for a different date. Comparison of LSTs shows good agreement with ground measurements in thermally homogeneous area. However, results in agriculture area with less homogeneity show

  7. Synergy of Satellite-Surface Observations for Studying the Properties of Absorbing Aerosols in Asia

    Science.gov (United States)

    Tsay, Si-Chee

    2010-01-01

    Through interaction with clouds and alteration of the Earth's radiation budget, atmospheric aerosols significantly influence our weather and climate. Monsoon rainfalls, for example, sustain the livelihood of more than half of the world's population. Thus, understanding the mechanism that drives the water cycle and freshwater distribution is high-lighted as one of the major near-term goals in NASA's Earth Science Enterprise Strategy. Every cloud droplet/ice-crystal that serves as an essential element in portraying water cycle and distributing freshwater contains atmospheric aerosols at its core. In addition, the spatial and temporal variability of atmospheric aerosol properties is complex due to their dynamic nature. In fact, the predictability of the tropical climate system is much reduced during the boreal spring, which is associated with the peak season of biomass burning activities and regional/long-range transport of dust aerosols. Therefore, to accurately assess the impact of absorbing aerosols on regional-to-global climate requires not only modeling efforts but also continuous observations from satellites, aircraft, networks of ground-based instruments and dedicated field experiments. Since 1997 NASA has been successfully launching a series of satellites the Earth Observing System - to intensively study, and gain a better understanding of, the Earth as an integrated system. Through participation in many satellite remote-sensing/retrieval and validation projects over the years, we have gradually developed and refined the SMART (Surface-sensing Measurements for Atmospheric Radiative Transfer) and COMMIT (Chemical, Optical & Microphysical Measurements of In-situ Troposphere) mobile observatories, a suite of surface remote sensing and in-situ instruments that proved to be vital in providing high temporal measurements, which complement the satellite observations. In this talk, we will present SMART-COMMIT which has played key roles, serving as network or supersite

  8. Potential and limitations of multidecadal satellite soil moisture observations for selected climate model evaluation studies

    Directory of Open Access Journals (Sweden)

    A. Loew

    2013-09-01

    Full Text Available Soil moisture is an essential climate variable (ECV of major importance for land–atmosphere interactions and global hydrology. An appropriate representation of soil moisture dynamics in global climate models is therefore important. Recently, a first multidecadal, observation-based soil moisture dataset has become available that provides information on soil moisture dynamics from satellite observations (ECVSM, essential climate variable soil moisture. The present study investigates the potential and limitations of this new dataset for several applications in climate model evaluation. We compare soil moisture data from satellite observations, reanalysis and simulations from a state-of-the-art land surface model and analyze relationships between soil moisture and precipitation anomalies in the different dataset. Other potential applications like model parameter optimization or model initialization are not investigated in the present study. In a detailed regional study, we show that ECVSM is capable to capture well the interannual and intraannual soil moisture and precipitation dynamics in the Sahelian region. Current deficits of the new dataset are critically discussed and summarized at the end of the paper to provide guidance for an appropriate usage of the ECVSM dataset for climate studies.

  9. Optimization of post-classification processing of high-resolution satellite image: A case study

    Institute of Scientific and Technical Information of China (English)

    DONG; Rencai; DONG; Jiajia; WU; Gang; DENG; Hongbing

    2006-01-01

    The application of remote sensing monitoring techniques plays a crucial role in evaluating and governing the vast amount of ecological construction projects in China. However, extracting information of ecological engineering target through high-resolution satellite image is arduous due to the unique topography and complicated spatial pattern on the Loess Plateau of China. As a result, enhancing classification accuracy is a huge challenge to high-resolution image processing techniques. Image processing techniques have a definitive effect on image properties and the selection of different parameters may change the final classification accuracy during post-classification processing. The common method of eliminating noise and smoothing image is majority filtering. However, the filter function may modify the original classified image and the final accuracy. The aim of this study is to develop an efficient and accurate post-processing technique for acquiring information of soil and water conservation engineering, on the Loess Plateau of China, using SPOT image with 2.5 rn resolution. We argue that it is vital to optimize satellite image filtering parameters for special areas and purposes, which focus on monitoring ecological construction projects. We want to know how image filtering influences final classified results and which filtering kernel is optimum. The study design used a series of window sizes to filter the original classified image, and then assess the accuracy of each output map and image quality. We measured the relationship between filtering window size and classification accuracy, and optimized the post-processing techniques of SPOT5satellite images. We conclude that (1) smoothing with the majority filter is sensitive to the information accuracy of soil and water conservation engineering, and (2) for SPOT5 2.5 m image, the 5×5 pixel majority filter is most suitable kernel for extracting information of ecological construction sites in the Loess Plateau of

  10. Stereological estimation of the orbital volume: a criterion standard study.

    Science.gov (United States)

    Acer, Niyazi; Sahin, Bünyamin; Ergür, Hayati; Basaloglu, Hulki; Ceri, Nazli Gülriz

    2009-05-01

    Several methodologies have been proposed to assess the orbital volume (OV). However, we have not seen a criterion standard study evaluating the results of the methodologies for the assessment of OV. In the current study, the actual OV of 9 dry skulls was measured using the water filling method as the criterion standard. Consecutive computed tomographic sections at a thickness of 1.5 mm were used to estimate the OV by means of the point counting method. The mean (SD) of the OV measured by the water filling method was 17.84 (1.56) cm3. By using the point counting method, it was 17.05 (1.69) cm3. There was no statistically significant difference between sides (P > 0.001). The results of the OV values obtained by the two methods were compared statistically. The agreements between the two methods were also evaluated using the Bland-Altman plots. There was no statistically significant difference between the OV measurements obtained by the stereological technique and water filling method. The described method could be used for the assessment of OV in vivo.

  11. A Comparative Study on Satellite- and Model-Based Crop Phenology in West Africa

    Directory of Open Access Journals (Sweden)

    Elodie Vintrou

    2014-02-01

    Full Text Available Crop phenology is essential for evaluating crop production in the food insecure regions of West Africa. The aim of the paper is to study whether satellite observation of plant phenology are consistent with ground knowledge of crop cycles as expressed in agro-simulations. We used phenological variables from a MODIS Land Cover Dynamics (MCD12Q2 product and examined whether they reproduced the spatio-temporal variability of crop phenological stages in Southern Mali. Furthermore, a validated cereal crop growth model for this region, SARRA-H (System for Regional Analysis of Agro-Climatic Risks, provided precise agronomic information. Remotely-sensed green-up, maturity, senescence and dormancy MODIS dates were extracted for areas previously identified as crops and were compared with simulated leaf area indices (LAI temporal profiles generated using the SARRA-H crop model, which considered the main cropping practices. We studied both spatial (eight sites throughout South Mali during 2007 and temporal (two sites from 2002 to 2008 differences between simulated crop cycles and determined how the differences were indicated in satellite-derived phenometrics. The spatial comparison of the phenological indicator observations and simulations showed mainly that (i the satellite-derived start-of-season (SOS was detected approximately 30 days before the model-derived SOS; and (ii the satellite-derived end-of-season (EOS was typically detected 40 days after the model-derived EOS. Studying the inter-annual difference, we verified that the mean bias was globally consistent for different climatic conditions. Therefore, the land cover dynamics derived from the MODIS time series can reproduce the spatial and temporal variability of different start-of-season and end-of-season crop species. In particular, we recommend simultaneously using start-of-season phenometrics with crop models for yield forecasting to complement commonly used climate data and provide a better

  12. Study of the $\\bar K N$ system and coupled channels in a finite volume

    CERN Document Server

    Torres, A Martínez; Jido, D; Oset, E

    2013-01-01

    We investigate the $\\bar KN$ and coupled channels system in a finite volume and study the properties of the $\\Lambda(1405)$ resonance. We calculate the energy levels in a finite volume and solve the inverse problem of determining the resonance position in the infinite volume. We devise the best strategy of analysis to obtain the two poles of the $\\Lambda(1405)$ in the infinite volume case, with sufficient precision to distinguish them.

  13. USAF Advanced Terrestrial Energy Study. Volume 2. Technology Handbook.

    Science.gov (United States)

    1983-04-01

    volume of Stirling svstems hecause the regenerator determines the dimensions of the system envelone. Table 27. STIRLING SYSTEM VOLUME (CUBIC FEET...Rankine Cycles Batteries Gas Turbines Stirling Engines Thermal Energy Storage 20. ABSTRACT (Confilime 4n roere. olde If neo**WY 41011184100140 & Wee bi A...TECHNOLOGY DESCRIPTIONS 13 Diesels, 13 Gas Turbines. 31 Stirlings , 49 Organic Rankine Cycle; 67 Fuel Cells 83 Photovoltaic Energy Conversion System, 102 Wind

  14. Preliminary study on migration pattern of the Tibetan antelope ( Pantholops hodgsonii) based on satellite tracking

    Science.gov (United States)

    Buho, Hoshino; Jiang, Z.; Liu, C.; Yoshida, T.; Mahamut, Halik; Kaneko, M.; Asakawa, M.; Motokawa, M.; Kaji, K.; Wu, X.; Otaishi, N.; Ganzorig, Sumiya; Masuda, R.

    2011-07-01

    The spatial and temporal patterns of the endangered Tibetan antelope or chiru ( Pantholops hodgsonii) have been studied using satellite-based ARGOS platform transmitter terminal (PTT) tracking data. The data was obtained from the satellite tracking of two female Tibetan antelopes that were collared with satellite transmitters and have been tracked from August 2007 to April 2009. Analysis of the locality data (LC) obtained, shows that both antelopes were migrant individuals, they shared the same calving ground surrounding lake Huiten (or Zhuonai lake), but different wintering pastures. Each antelope covered 250-300 km from the wintering to summer pastures. Annual range consisted of a core area that was used for at least 9 months; a calving ground used for a short time (from 8-20 days); and temporal pastures used during migration to and from the calving ground. Seasonal migration cycle was about 3 months, 27-30 days to reach the calving ground; 8-20 days staying there; and 36-40 days returning to the core area. Examination of the spatial distribution during migration showed that both chiru crossed the Qinghai-Tibetan railway (QTR) and the Golmud-Lhasa highway (GLH) at least two times, and reached calving ground (118-120 km from there) in 8 days, maintaining an average speed of 15 km per day. However, the return migration took twice as long (from 14 to 16 days). Each time, after reaching the QTR and GLH, the antelopes spent 20-40 days in that area, probably looking for passages and waiting. So far, we suppose that the QTR and the GLH have become a hindrance to the migration of the Tibetan antelopes and seriously delay their movement to and from the calving area. Extended aggregation of the herds of Tibetan antelopes along the QTR and the GLH may impact negatively with increased mortality among offspring, the spread of various diseases and overgrazing of pastures.

  15. Gold Minerogenetic Prognosis Using Satellite Data: Case Study of Paishanlou Gold Mine, Liaoning Province, China

    Institute of Scientific and Technical Information of China (English)

    Malogo J M Kongola; Wang Ende

    2005-01-01

    The major scientific goal of using satellite data for mineral prospecting in the study area was two-fold: (a) mapping geology, faults and fractures that localize ore deposits; (b) recognizing hydrothermally altered rocks by interpreting their spectral signatures. The lithology, properties, and geological relations of the rocks were key to understanding such varied phenomena as convection, melting and transport mechanisms, rock deformation and alteration, the sources of magnetic anomalies, and the hydrothermal circulation and formation of gold deposits. Satellite data were enhanced using the following techniques: band combinations, ratios, directional sharpening filtering, Laplacian transform, spatial convolution, and density slicing. By mapping a larger area, the Paishanlou Gold Mine was discovered to be located within an accommodation zone, with three significant populations of faults having bearings of 95, 145, and 180 degrees. Faults bearing 145 degrees make up the faults of the main shear zone. The faults bearing 180 degrees have large sinistral offsets, typically 1.5 km, and form a synthetic-antithetic set with the faults bearing 145 degrees, which have dextral displacements of tens of meters. In the Landsat ETM+ image composed of bands 7-4-2 RGB, gneiss rocks were clearly seen as red purple, and granitic and plagioclase bodies in pale brown/pink. The strongest alteration signature in the image was found along the detachment fault antiform located closest to the mine and the plutons responsible for the Paishanlou gold mineralization. Satellite image interpretation coupled with field surveys led to the identification of iron mineral composites, hydrothermally altered areas, fractures, and an accommodation zone. These anomalies finally resulted in the discovery of three new gold-mineralized sites.

  16. Importance of the test volume on the lag phase in biodegradation studies

    DEFF Research Database (Denmark)

    Ingerslev, F.; Torang, Lars; Nyholm, Niels

    2000-01-01

    Increasing the total volume of test medium resulted in decreased lag times (TL) in biodegradability shake flask batch tests conducted with either surface water or with synthetic mineral medium inoculated with supernatant from settled activated sludge. Experiments were performed with test volumes...... volume tended to increase the lag time, even when a single test batch was redistributed into smaller flasks. With 5 ml supernatant added to different volumes of mineral medium, lag times for PNP were independent of the test volume in a range from 10 to 1,000 ml. At small volumes of 10 ml or less...... small inoculations or with too small test volumes, biodegradation may fail randomly. A straightforward practical implication of the findings is that the test volume in biodegradability tests can significantly influence the lag time and thus sometimes be decisive for the outcome in biodegradation studies....

  17. A satellite based study of tropospheric bromine explosion events and their linkages to polar cyclone development

    Science.gov (United States)

    Blechschmidt, Anne-Marlene; Richter, Andreas; Burrows, John P.; Kaleschke, Lars; Strong, Kimberly; Theys, Nicolas; Weber, Mark; Zhao, Xiaoyi; Zien, Achim; Hodges, Kevin I.

    2016-04-01

    Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by the UV-vis satellite instruments GOME-2/MetOp-A and SCIAMACHY/Envisat over Arctic and Antarctic sea ice in polar spring. The plumes are associated with an autocatalytic chemical chain reaction involving tropospheric ozone depletion and initiated by the release of bromine from cold brine-covered ice or snow to the atmosphere. This influences atmospheric chemistry as it affects the oxidising capacity of the troposphere through OH production and may also influence the local weather/temperature of the polar atmosphere, as ozone is a major greenhouse gas. Here, we make combined use of satellite retrievals and numerical model simulations to study individual BrO plume cases in the polar atmosphere. In agreement with previous studies, our analysis shows that the plumes are often transported by high latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. Moreover, general characteristics of bromine explosion events linked to transport by polar weather systems, such as frequency, spatial distribution and favourable weather conditions are derived based on a new detection method. Our results show that BrO cyclone transport events are by far more common in the Antarctic than in the Arctic.

  18. CO2 laser as a possible candidate for optical transmitter in free-space satellite-ground-satellite laser communication: a case study

    Science.gov (United States)

    Kumar, M. A.; Naik, Govind; Shenoy, N. V.; Rao, Mandavilli M.

    1999-04-01

    Terrestrial fiber optic communication systems handle most of the inter-continental communication systems today. However recent studies indicate that these links, in spite of their huge bandwidth will be saturated in the near future. Hence attempts are being made is augment and may be even replace these by inter satellite links (ISLs). Though high power laser diodes have been found to be suitable for ISLs, they are unfortunately inadequate for satellite-ground links (SGL and GSL) as they are not powerful enough. So we have to look for more powerful lasers for SGLs & GSLs. One possible candidate is the CO2 laser. It is a gas laser. It provides a number of advantages over other sources. They include high life time, high efficiency and stability. Besides it can generate a high power continuous wave and requires only radiative cooling. CO2 can provide a high bit rate and long range transmission with low bit error rate. Also CO2 laser is in near infra-red and hence the turbulence effects due to clouds is minimum. All these make CO2 laser a very economical choice. The use of optical communication in GSLs provides many advantages over radio links. Laser being a high energy source provides the advantage of greater bandwidth, smaller beam divergence angles, smaller antennae, greater security and a new spectrum. Lesser power consumption and smaller size make it more suitable for use in a satellite. The present paper deals with a case study of a CO2 laser based free space optical communication link by making the link budget analysis.

  19. Control volume based hydrocephalus research; a phantom study

    Science.gov (United States)

    Cohen, Benjamin; Voorhees, Abram; Madsen, Joseph; Wei, Timothy

    2009-11-01

    Hydrocephalus is a complex spectrum of neurophysiological disorders involving perturbation of the intracranial contents; primarily increased intraventricular cerebrospinal fluid (CSF) volume and intracranial pressure are observed. CSF dynamics are highly coupled to the cerebral blood flows and pressures as well as the mechanical properties of the brain. Hydrocephalus, as such, is a very complex biological problem. We propose integral control volume analysis as a method of tracking these important interactions using mass and momentum conservation principles. As a first step in applying this methodology in humans, an in vitro phantom is used as a simplified model of the intracranial space. The phantom's design consists of a rigid container filled with a compressible gel. Within the gel a hollow spherical cavity represents the ventricular system and a cylindrical passage represents the spinal canal. A computer controlled piston pump supplies sinusoidal volume fluctuations into and out of the flow phantom. MRI is used to measure fluid velocity and volume change as functions of time. Independent pressure measurements and momentum flow rate measurements are used to calibrate the MRI data. These data are used as a framework for future work with live patients and normal individuals. Flow and pressure measurements on the flow phantom will be presented through the control volume framework.

  20. Sampling errors for satellite-derived tropical rainfall - Monte Carlo study using a space-time stochastic model

    Science.gov (United States)

    Bell, Thomas L.; Abdullah, A.; Martin, Russell L.; North, Gerald R.

    1990-01-01

    Estimates of monthly average rainfall based on satellite observations from a low earth orbit will differ from the true monthly average because the satellite observes a given area only intermittently. This sampling error inherent in satellite monitoring of rainfall would occur even if the satellite instruments could measure rainfall perfectly. The size of this error is estimated for a satellite system being studied at NASA, the Tropical Rainfall Measuring Mission (TRMM). First, the statistical description of rainfall on scales from 1 to 1000 km is examined in detail, based on rainfall data from the Global Atmospheric Research Project Atlantic Tropical Experiment (GATE). A TRMM-like satellite is flown over a two-dimensional time-evolving simulation of rainfall using a stochastic model with statistics tuned to agree with GATE statistics. The distribution of sampling errors found from many months of simulated observations is found to be nearly normal, even though the distribution of area-averaged rainfall is far from normal. For a range of orbits likely to be employed in TRMM, sampling error is found to be less than 10 percent of the mean for rainfall averaged over a 500 x 500 sq km area.

  1. Study of the triple-mass Tethered Satellite System under aerodynamic drag and J2 perturbations

    Science.gov (United States)

    Razzaghi, Pourya; Assadian, Nima

    2015-11-01

    The dynamics of multi-tethered satellite formations consisting of three masses are studied in this paper. The triple-mass triple-tethered satellite system is modeled under the low Earth orbit perturbations of drag and Earth's oblateness and its equilibrium conditions are derived. It is modeled as three equal end-masses connected by a uniform-mass straight tether. The lengths of tethers are supposed to be constant and in this manner the angles of the plane consisting the masses are taken as the state variables of the system. The governing equations of motion are derived using Lagrangian approach. The aerodynamic drag perturbation is expressed as an external non-conservative force and the Earth oblateness (J2 perturbation) is considered as a term of potential energy. The equilibrium conditions of this system are found and their stability is investigated through the linear stability theory. Then, the results are verified by using a nonlinear simulation for three types of equilibrium conditions.

  2. Satellite-based Studies on Large-Scale Vegetation Changes in China

    Institute of Scientific and Technical Information of China (English)

    Xia Zhao; Daojing Zhou; Jingyun Fang

    2012-01-01

    Remotely-sensed vegetation indices,which indicate the density and photosynthetic capacity of vegetation,have been widely used to monitor vegetation dynamics over broad areas.In this paper,we reviewed satellite-based studies on vegetation cover changes,biomass and productivity variations,phenological dynamics,desertification,and grassland degradation in China that occurred over the past 2-3 decades.Our review shows that the satellite-derived index (Normalized Difference Vegetation Index,NDVI) during growing season and the vegetation net primary productivity in major terrestrial ecosystems (for example forests,grasslands,shrubs,and croplands) have significantly increased,while the number of fresh lakes and vegetation coverage in urban regions have experienced a substantial decline.The start of the growing season continually advanced in China's temperate regions until the 1990s,with a large spatial heterogeneity.We also found that the coverage of sparsely-vegetated areas declined,and the NDVI per unit in vegetated areas increased in arid and semi-arid regions because of increased vegetation activity in grassland and oasis areas.However,these results depend strongly not only on the periods chosen for investigation,but also on factors such as data sources,changes in detection methods,and geospatial heterogeneity.Therefore,we should be cautious when applying remote sensing techniques to monitor vegetation structures,functions,and changes.

  3. Autoionization study of the Argon 2p satellites excited near the argon 2s threshold

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Glans, P.; Hemmers, O. [Univ. of Nevada, Las Vegas, NV (United States)] [and others

    1997-04-01

    The dynamics of near-threshold photoionization is a complex phenomenon in which the many-electron character of the wavefunctions plays an important role. According to generalized time-independent resonant scattering theory, the transition matrix element from an initial state to a final state is the summation of the amplitudes of direct photoionization and an indirect term in which intermediate states are involved and the resonant behavior is embedded. Studies of the interference effects of intermediate states have been explored in the cases where the direct term is negligible. In the present work, electron time-of-flight spectra of the Ar 2p satellites were measured at two angles (magic and 0{degrees}) in the dipole plane with the exciting photon energy tuned in the vicinity of the Ar 2s threshold. For excitation far below or above the 2s threshold, the 2p satellites spectrum is dominated by 3p to np shakeup contributions upon the ionization of a 2p electron.

  4. The study of gravity gradient effect on attitude of low earth orbit satellite

    Science.gov (United States)

    Hamzah, Nor Hazadura; Yaacob, Sazali; Muthusamy, Hariharan; Hamzah, Norhizam; Ghazali, Najah

    2013-04-01

    Simulations and mathematical models are increasingly used to assist the process of decision making in engineering design. The objective of this paper is to simulate the linear attitude dynamics of small satellites under gravity gradient torque which is inherent in low earth orbit. The equations were first derived in their nonlinear form, and then manipulated and simulated in their linear form. Simulation results demonstrate the importance of choosing the appropriate values of satellite's moment of inertia in designing phase of a satellite.

  5. Using Satellite Imagery to Monitor the Major Lakes; Case Study Lake Hamun

    Science.gov (United States)

    Norouzi, H.; Islam, R.; Bah, A.; AghaKouchak, A.

    2015-12-01

    Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes would provide invaluable information for policy-makers and local people. As part of a comprehensive study, we aim to monitor the land-cover/ land-use changes in the world's major lakes using satellite observations. As a case study, Hamun Lake which is a pluvial Lake, also known as shallow Lake, located on the south-east of Iran and adjacent to Afghanistan, and Pakistan borders is investigated. The Lake is the main source of resources (agriculture, fishing and hunting) for the people around it and politically important in the region since it is shared among three different countries. The purpose of the research is to find the Lake's area from 1972 to 2015 and to see if any drought or water resources management has affected the lake. Analyzing satellites imagery from Landsat shows that the area of the Lake changes seasonally and intra-annually. Significant seasonal effects are found in 1975,1977, 1987, 1993, 1996, 1998, 2000, 2009 and 2011, as well as, substantial amount of shallow water is found throughout the years. The precipitation records as well as drought historical records are studied for the lake's basin. Meteorological studies suggest that the drought, decrease of rainfalls in the province and the improper management of the Lake have caused environmental, economic and geographical consequences. The results reveal that lake has experienced at least two prolong dryings since 1972 which drought cannot solely be blamed as main forcing factor.Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes

  6. Recent studies in satellite observations of three-dimensional magnetic reconnection

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Magnetic reconnection is a main process converting the magnetic energy into thermal and kinetic energy in plasmas. It is one of the fundamental problems of crucial importance not only to space plasmas physics and space weather studies,such as the solar flare,coronal mass ejections and magnetospheric substorms,but also to the stability analysis in magnetically confined fusion. In general,except for cases with periodical boundary conditions,three-dimensional(3D) magnetic re-connection occurs on magnetic separatrices generated by magnetic nulls. Here we briefly introduce/review the theories and some recent satellite observations of 3D magnetic reconnection. Topics to be further studied are also discussed.

  7. Developing a Satellite Based Automatic System for Crop Monitoring: Kenya's Great Rift Valley, A Case Study

    Science.gov (United States)

    Lucciani, Roberto; Laneve, Giovanni; Jahjah, Munzer; Mito, Collins

    2016-08-01

    The crop growth stage represents essential information for agricultural areas management. In this study we investigate the feasibility of a tool based on remotely sensed satellite (Landsat 8) imagery, capable of automatically classify crop fields and how much resolution enhancement based on pan-sharpening techniques and phenological information extraction, useful to create decision rules that allow to identify semantic class to assign to an object, can effectively support the classification process. Moreover we investigate the opportunity to extract vegetation health status information from remotely sensed assessment of the equivalent water thickness (EWT). Our case study is the Kenya's Great Rift valley, in this area a ground truth campaign was conducted during August 2015 in order to collect crop fields GPS measurements, leaf area index (LAI) and chlorophyll samples.

  8. Land mobile satellite communication system. Volume 2: Traffic analysis and market demand for the land mobile communications system in the European scenario

    Science.gov (United States)

    Carnebianca, C.; Pavesi, B.; Tuozzi, A.; Capone, R.

    1986-06-01

    The socioeconomic desirability in terms of market demand, technical economic feasibility, and price-performance for a Land Mobile Communication system ground based and/or satellite aided, able to satisfy the request of the traffic demand, foreseable in the 1995-2005 time frame, for the Western European countries was assessed. The criterion of economic value of the mobile system is considered as the driving element. The presence of gaps in the terrestrial system and reasonable traffic extrapolations suggest a very attractive role for a land mobile satellite communications mission.

  9. Wisconsin Elementary Teacher Education Project. Volume VI, Feasibility Study: Pricing and Economic Analysis Study. Final Report.

    Science.gov (United States)

    Wisconsin Univ., Madison.

    This document is the second volume of the feasibility study report for the Wisconsin Elementary Teacher Education Project. It provides in part 1 data on program, planning and budgeting, including cost figures for preparing students in the present and new programs, marginal expenses, and costs for implementing the program on other campuses. Part 2…

  10. THE PSYCHOANALYTIC STUDY OF THE CHILD. PSYCHOANALYTIC STUDY OF THE CHILD SERIES, VOLUME 22.

    Science.gov (United States)

    EISSLER, RUTH S., ED.; AND OTHERS

    TWENTY ARTICLES ARE INCLUDED IN THIS VOLUME, THE 22ND IN THE PSYCHOLOGICAL STUDY OF THE CHILD SERIES. PAPERS ON PSYCHOPATHOLOGY AND THERAPY INTERPRET LOSING AND BEING LOST, OBSTACLES TO PSYCHOANALYTIC CURE, AND AFFECT CONTROL. ASPECTS OF PSYCHOANALYTIC THEORY CONSIDERED ARE FREUD'S CONCEPT OF PRIMAL REPRESSION, CONCEPTS OF STRUCTURE AND…

  11. Study of Automatic Fiber Placement Manipulator’s Robotic Kinematics Manipulability Based on Volume Element

    Directory of Open Access Journals (Sweden)

    Ge Xinfeng

    2013-02-01

    Full Text Available The method is proposed based on volume element in order to measure the manipulator’s robotic kinematics manipulability. Then studied the series redundant automatic fiber placement robotic manipulator’s operation space, draw the conclusion that the greater of the robotic manipulator’s operation space volume, the better of the robotic manipulator’s manipulability, volume element based on redundant robotic manipulator’s kinematics is proposed as an operational performance index. n-DOF serial robotic manipulator’s operation space is n-dimensional Riemannian manifold, the n-dimensional Riemannian manifold volume is calculated using the moving coordinate system and the exterior product definition in differential geometry and get the robotic manipulator’s operation space volume then compared the obtained results with the operation space volume using inner product determinant in the literature, it shows that the volume element as a kinematics operational performance index is feasible.

  12. Tropical forest monitoring, combining satellite and social data, to inform management and livelihood implications: Case studies from Indonesian West Timor

    Science.gov (United States)

    Fisher, Rohan

    2012-06-01

    Deforestation in the world's tropics is an urgent international issue. One response has been the development of satellite based monitoring initiatives largely focused on the carbon rich forests of western Indonesia. In contrast this study focuses on one eastern Indonesian district, Kabupaten Kupang, which has some of the largest and least studied tracts of remaining forest in West Timor. A combination of remote sensing, GIS and social science methods were used to describe the state of forests in Kabupaten Kupang, how and why they are changing. Using satellite imagery, case studies and on-ground interviews, this study explores the proposition that transdisciplinary local social, cultural and biophysical knowledge is important for effectively using remotely sensed data as a tool to inform local management policies. When compared to some other parts of Indonesia, the rate and extent of deforestation in West Timor was found to be relatively small and a satellite based assessment alone could conclude that it is not a critical issue. However this study showed that when on-ground social data are coupled with (such) satellite-based data a more complex picture emerges, related to key livelihood issues. The causes of forest cover change were found to be multivariate and location specific, requiring management approaches tailored to local social issues. This study suggests that integrative research can maximise the utility of satellite data for understanding causation and thus informing management strategies. In addition, the satellite based assessment found that at the time of the study less than 4% of forested land was within national parks and nature reserves and less than a third of the protected catchment forest zone was forested. These data suggest considerable scope for upland re-forestation activities or the redrawing of protected forest boundaries.

  13. A study of temperature's spatial distribution in Neuquen River valley through satellite imaging

    Directory of Open Access Journals (Sweden)

    Marisa Gloria Cogliati

    2010-01-01

    Full Text Available This paper looks into the spatial distribution of brightness and surface temperature through the use of LAND SAT7 ETM+ and NO AA-AVHRR satellite imagery in the cultivated valley of the Neuquén river. Studying the spatial distribution of temperatures in an area with a somewhat complex terrain requires the use of a great density of meteorological measurements. It is often impossible to obtain the right density of the argometeorological network due to the high installation and maintenance costs. Remote sensors provide a large flow of information in various resolutions, at considerably lower costs. Determining the valley's warm and cold zones would allow for more efficient irrigation and frost-protection methods, and it would provide tools to improve the area's productive planning.

  14. A Deep Study of the Dwarf Satellites Andromeda XXVIII & Andromeda XXIX

    CERN Document Server

    Slater, Colin T; Martin, Nicolas F; Tollerud, Erik J; Ho, Nhung

    2015-01-01

    We present the results of a deep study of the isolated dwarf galaxies Andromeda XXVIII and Andromeda XXIX with Gemini/GMOS and Keck/DEIMOS. Both galaxies are shown to host old, metal-poor stellar populations with no detectable recent star formation, conclusively identifying both of them as dwarf spheroidal galaxies (dSphs). And XXVIII exhibits a complex horizontal branch morphology, which is suggestive of metallicity enrichment and thus an extended period of star formation in the past. Decomposing the horizontal branch into blue (metal poor, assumed to be older) and red (relatively more metal rich, assumed to be younger) populations shows that the metal rich are also more spatially concentrated in the center of the galaxy. We use spectroscopic measurements of the Calcium triplet, combined with the improved precision of the Gemini photometry, to measure the metallicity of the galaxies, confirming the metallicity spread and showing that they both lie on the luminosity-metallicity relation for dwarf satellites. ...

  15. Rain induced attenuation studies for V-band satellite communication in tropical region

    Science.gov (United States)

    Badron, Khairayu; Ismail, Ahmad Fadzil; Din, Jafri; Tharek, Abd. Rahman

    2011-04-01

    Satellite communications operating at 10 GHz and above in the tropics suffer severe signal degradation due to rain. Attenuation due to rain at 38 GHz had been measured for a period of 20 months in Malaysia. Analyses carried out include seasonal variations, diurnal effects and the annual cumulative distributions. Obtained results were compared with several established prediction models including the ITU-R. The rain fade characteristics were also investigated in determining the levels of signal loss and fading. In addition, the studies highlight several potential fade mitigation techniques that can be embarked. These fundamental aprehensions are very critical for future earth space communication link design and can be exploited as preliminary groundwork plan for the researchers as well as engineers.

  16. Satellite Altimetry And Radiometry for Inland Hydrology, Coastal Sea-Level And Environmental Studies

    Science.gov (United States)

    Tseng, Kuo-Hsin

    In this study, we demonstrate three environmental-related applications employing altimetry and remote sensing satellites, and exemplify the prospective usage underlying the current progressivity in mechanical and data analyzing technologies. Our discussion starts from the improved waveform retracking techniques in need for altimetry measurements over coastal and inland water regions. We developed two novel auxiliary procedures, namely the Subwaveform Filtering (SF) method and the Track Offset Correction (TOC), for waveform retracking algorithms to operationally detect altimetry waveform anomalies and further reduce possible errors in determination of the track offset. After that, we present two demonstrative studies related to the ionospheric and tropospheric compositions, respectively, as their variations are the important error sources for satellite electromagnetic signals. We firstly compare the total electron content (TEC) measured by multiple altimetry and GNSS sensors. We conclude that the ionosphere delay measured by Jason-2 is about 6-10 mm shorter than the GPS models. On the other hand, we use several atmospheric variables to study the climate change over high elevation areas. Five types of satellite data and reanalysis models were used to study climate change indicators. We conclude that the spatial distribution of temperature trend among data products is quite different, which is probably due to the choice of various time spans. Following discussions about the measuring techniques and relative bias between data products, we applied our improved altimetry techniques to three environmental science applications with helps of remote sensing imagery. We first manifest the detectability of hydrological events by satellite altimetry and radiometry. The characterization of one-dimensional (along-track) water boundary using former Backscattering Coefficient (BC) method is assisted by the two-dimensional (horizontal) estimate of water extent using the Moderate

  17. Nanosar-case study of synthetic aperture radar for nano-satellites

    NARCIS (Netherlands)

    Engelen, S.; Oever, M. van den; Mahapatra, P.; Sundaramoorthy, P.; Gill, E.; Meijer, R.J.; Verhoeven, C.

    2012-01-01

    Nano-satellites have a cost advantage due to their low mass and usage of commercial-off-the-shelf technologies. However, the low mass also restricts the functionality of a nano-satellite's payload. Typically, this would imply instruments with very low to low resolution and accuracy, essentially

  18. Nanosar-case study of synthetic aperture radar for nano-satellites

    NARCIS (Netherlands)

    Engelen, S.; Oever, M. van den; Mahapatra, P.; Sundaramoorthy, P.; Gill, E.; Meijer, R.J.; Verhoeven, C.

    2012-01-01

    Nano-satellites have a cost advantage due to their low mass and usage of commercial-off-the-shelf technologies. However, the low mass also restricts the functionality of a nano-satellite's payload. Typically, this would imply instruments with very low to low resolution and accuracy, essentially ruli

  19. A long-term satellite study of aerosol effects on convective clouds in Nordic background air

    Directory of Open Access Journals (Sweden)

    M. K. Sporre

    2013-05-01

    Full Text Available Aerosol-cloud interactions constitute a~major uncertainty in future climate predictions. This study combines 10 yr of ground-based aerosol particle measurements from 2 Nordic background stations (Vavihill and Hyytiälä with MODIS (Moderate Resolution Imaging Spectroradiometer satellite data of convective clouds. The merged data are used to examine the indirect aerosol effects on convective clouds over the Nordic countries. From the satellite scenes, vertical profiles of cloud droplet effective radius (re are created by plotting re against cloud top temperature. The profiles have been divided according to aerosol loading but also modeled meteorological parameters from the ECMWF (European Centre for Medium-Range Forecasts. Furthermore, weather radar data from the BALTEX (Baltic Sea Experiment and ground based precipitation measurements from several ground-based meteorological measurement stations have been investigated to determine whether aerosols affect precipitation intensity and amount. Higher aerosol number concentrations result in smaller re throughout the entire profiles at both stations. Profiles associated with no or little precipitation have smaller droplets than those associated with more precipitation. Furthermore, an increase in aerosol loadings results in a suppression of precipitation rates, when the vertical extent of the clouds has been taken into account. Clouds with greater vertical extent have the highest precipitation rates and are most sensitive to aerosol perturbations. Nevertheless, meteorological parameters such as the vertical extent of the clouds, the atmospheric instability and the relative humidity in the lower atmosphere affect the amount of precipitation that reaches the ground more than the aerosols do. The combination of these ground-based and remote sensing datasets provides a unique long-term study of the effects of aerosols on convective clouds over the Nordic countries.

  20. A study of L-dependent Pc3 pulsations observed by low Earth orbiting CHAMP satellite

    Directory of Open Access Journals (Sweden)

    D. C. Ndiitwani

    2010-02-01

    Full Text Available Field line resonances (FLR driven by compressional waves are an important mechanism for the generation of ULF geomagnetic pulsations observed at all latitudes during local daytime. References to observations of toroidal standing Alfvén mode oscillations with clearly L-dependent frequencies from spacecraft in the outer magnetosphere for L>3 are limited in the literature. Such observations in the inner magnetosphere for L<3 have not yet been reported in the literature. This study offers two interesting case studies of observations of ULF waves by the low Earth orbiting CHAMP satellite. The magnetic field measurements from CHAMP, which are of unprecedented accuracy and resolution, are compared to Hermanus magnetometer data for times when CHAMP crosses the ground station L-shell, namely for 13 February 2002 and 18 February 2003. The data were analysed for Pc3 pulsation activity using the Maximum Entropy Spectral Analysis (MESA method to visualise FLRs in the vector magnetometer data. For the first time observations of Pc3 toroidal oscillations with clearly L-dependent frequencies for lower L-shell values (L<3 observed by an LEO satellite are reported. These observations show FLR frequencies increasing as a function of decreasing latitude down to L=1.6 and then decreasing as a result of the larger plasma density of the upper ionosphere. The L-dependent frequency oscillations were observed in the presence of a broadband compressional wave spectrum. Our observations thus confirm the well-known magnetohydrodynamic (MHD wave theoretical prediction of a compressional wave being the driver of the field line resonance.

  1. Cadastral Resurvey using High Resolution Satellite Ortho Image - challenges: A case study in Odisha, India

    Science.gov (United States)

    Parida, P. K.; Sanabada, M. K.; Tripathi, S.

    2014-11-01

    Advancements in satellite sensor technology enabling capturing of geometrically accurate images of earth's surface coupled with DGPS/ETS and GIS technology holds the capability of large scale mapping of land resources at cadastral level. High Resolution Satellite Images depict field bunds distinctly. Thus plot parcels are to be delineated from cloud free ortho-images and obscured/difficult areas are to be surveyed using DGPS and ETS. The vector datasets thus derived through RS/DGPS/ETS survey are to be integrated in GIS environment to generate the base cadastral vector datasets for further settlement/title confirmation activities. The objective of this paper is to illustrate the efficacy of a hybrid methodology employed in Pitambarpur Sasana village under Digapahandi Tahasil of Ganjam district, as a pilot project, particularly in Odisha scenario where the land parcel size is very small. One of the significant observations of the study is matching of Cadastral map area i.e. 315.454 Acres, the image map area i.e. 314.887 Acres and RoR area i.e. 313.815 Acre. It was revealed that 79 % of plots derived by high-tech survey method show acceptable level of accuracy despite the fact that the mode of area measurement by ground and automated method has significant variability. The variations are more in case of Government lands, Temple/Trust lands, Common Property Resources and plots near to river/nalas etc. The study indicates that the adopted technology can be extended to other districts and cadastral resurvey and updating work can be done for larger areas of the country using this methodology.

  2. Evaluating the Road Safety Design through High Resolution Satellite Image: A Case Study of Karachi Metropolitan

    Directory of Open Access Journals (Sweden)

    Zubair Salman

    2016-01-01

    Full Text Available Humanity is suffering from numerous natural, technological and health related hazards. Urban Road crash is one of the growing health issues these days in both developed and developing countries. Pakistan stands 1st in Asia and 48th in the world in this regard. Similarly, the metropolitan city of Pakistan, Karachi; ranks fourth in the list. Various reasons are responsible for these crashes in Karachi. Around 34% of crashes in the city were accounted due to errors in road geometry. In this study use of high resolution satellite imagery made it possible for identifying geometrical errors at the U-turns on major arteries of the city. It was also recognized that most of the U-turns were built on the fastest lane of the roads with average distance of 1.1 Km apart, are marked as vulnerable for considerable number of severe injury and fatal crashes. Moreover, inlet wall of all median U-turns were found broken, suggested that the car crash had occurred at least once. To cross check this observation, nearly 120 U-turns were surveyed and marked on the satellite imagery based on convenience. Trained professionals interviewed the people working/living nearby the U-turns. Out of 120 U-turns studied, 72.5% were without wall/median and 27.5% were with wall/median. Average number of people got injured or died due to crashes were statistically significant (p<0.05 between the above mentioned types of U-turns. In order to reduce geometrical errors use of RS (Remote Sensing and GIS (Geographical Information System techniques are strongly suggested to be incorporated while planning road design in the city. This would certainly save the resources particularly the lives of the people.

  3. Severe thunderstorm activity over Bihar on 21st April, 2015: a simulation study by satellite based Nowcasting technique

    Science.gov (United States)

    Goyal, Suman; Kumar, Ashish; Sangar, Ghansham; Mohapatra, M.

    2016-05-01

    Satellite based Nowcasting technique is customized version of Forecast and Tracking the Evolution of Cloud Clusters (ForTraCC), it uses the extrapolation technique that allows for the tracking of Mesoscale convective systems (MCS) radiative and morphological properties and forecasts the evolution of these properties (based on cloud-top brightness temperature and area of the cloud cluster) up to 360 minutes, using infrared satellite imagery. The Thermal Infrared (TIR) channel of the weather satellite has been broadly used to study the behaviour of the cloud systems associated with deep convection. The main advantage of this approach is that for most of the globe the best statistics can only be obtained from satellite observations. Such a satellite survey would provide the statistics of MCSs covering the range of meteorological conditions needed to generalize the result and on the other hand only satellite observations can cover the very large range of space and time scale. The algorithm script is taken from Brazilian Scientist Dr. Danial Vila and implemented it into the Indian environment and made compatible with INSAT-3D hdf5 data format. For Indian region it utilizes the INSAT-3D satellite data of TIR1 (10.8 μm) channel and creates nowcast. The output is made compatible with GUI based software MIAS by generating the output in hdf5 format for better understanding and analysis of forecast. The main features of this algorithm are detection of Cloud Cluster based on Cloud Top Brightness Temperature (CTBT) and area i.e. ≤235 ºK and ≥2400 km2 respectively. The tracking technique based on MCS overlapping areas in successive images. The script has been automized in Auxiliary Data Processing System (ADPS) and generating the forecast file in every half an hour and convert the output file in geotiff format. The geotiff file is easily converted into KMZ file format using ArcGIS software to overlay it on google map and hosted on the web server.

  4. Volume reflection angle study as a function of crystal curvature

    Science.gov (United States)

    Biryukov, V. M.

    2016-10-01

    We compare the volume reflection angles measured for protons and electrons over a wide energy range from 1 to 400 GeV in Si and Ge bent crystals at PNPI, IHEP, SLAC, and CERN with the predictions of FLUX and CATCH simulation codes based on binary collisions (FLUX) and continuum model (CATCH). We show good consistency of the data taken by many experimental groups, in good agreement with earlier published predictions.

  5. Studies in Intelligence. Volume 54, Number 4, December 2010

    Science.gov (United States)

    2010-12-01

    Web, which search engine spiders cannot index.27 What Do Policymakers Want? Policymakers require informa- tion as much as ever, but the IC is no...the blue sky in the direction of Korea saying, “Ah, Fatherland, my liberated Fatherland!” Volume II: Sabotaging American Machinations Chon’s moment...June], Bookshelf) Rome’s Wars in Parthia: Blood in the Sand by Rose Mary Sheldon (54 3 [September], Bookshelf) Shadows On The Mountains: The Allies

  6. Object-based Evaluation of Satellite Precipitation Retrievals: A Case Study of the Summer Season over CONUS

    Science.gov (United States)

    Li, J.; Xu, P.

    2015-12-01

    Satellite precipitation retrievals that have high spatial and temporal resolutions are suitable for various applications, such as hydrologic modeling and watershed management. Many validation studies have been established to understand the strengths and limitations of these satellite precipitation retrievals. In this study, an object-based validation approach is adopted to evaluate several satellite precipitation retrievals focusing on the spatial and geometric patterns of precipitation. This object-based validation approach identifies precipitation objects using an image processing technique referred to as watershed transform. Several object attributes are diagnosed and analyzed based on the distance measurement. Three object-based verification scores are summarized to determine the overall performances of satellite precipitation retrievals. The Integrated Multi-satellitE Retrievals for GPM (IMERG) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) were evaluated using the object-based approach. The NOAA stage IV MPE multi-sensor composite rain analysis was utilized as the ground observations. The comparative assessments were conducted at 0.25° by 0.25° on a daily scale in the summer season of 2014 over the continental United States (CONUS). The results suggest that IMERG possesses the similar spatial pattern of local-scale precipitation areas against stage IV observations. In addition, IMERG depicts the sizes and locations of precipitation areas more accurately against stage IV.

  7. Study of accurate volume measurement system for plutonium nitrate solution

    Energy Technology Data Exchange (ETDEWEB)

    Hosoma, T. [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works

    1998-12-01

    It is important for effective safeguarding of nuclear materials to establish a technique for accurate volume measurement of plutonium nitrate solution in accountancy tank. The volume of the solution can be estimated by two differential pressures between three dip-tubes, in which the air is purged by an compressor. One of the differential pressure corresponds to the density of the solution, and another corresponds to the surface level of the solution in the tank. The measurement of the differential pressure contains many uncertain errors, such as precision of pressure transducer, fluctuation of back-pressure, generation of bubbles at the front of the dip-tubes, non-uniformity of temperature and density of the solution, pressure drop in the dip-tube, and so on. The various excess pressures at the volume measurement are discussed and corrected by a reasonable method. High precision-differential pressure measurement system is developed with a quartz oscillation type transducer which converts a differential pressure to a digital signal. The developed system is used for inspection by the government and IAEA. (M. Suetake)

  8. Adrenal gland volume measurement in septic shock and control patients: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Nougaret, Stephanie; Aufort, S.; Gallix, B. [Hopital Saint Eloi, Department of Abdominal Imaging, CHU Montpellier, Montpellier, Cedex 5 (France); Jung, B.; Chanques, G.; Jaber, S. [Hopital Saint Eloi, Intensive Care Unit, Department of Critical Care and Anesthesiology: DAR B, CHU Montpellier, Montpellier, Cedex 5 (France)

    2010-10-15

    To compare adrenal gland volume in septic shock patients and control patients by using semi-automated volumetry. Adrenal gland volume and its inter-observer variability were measured with tomodensitometry using semi-automated software in 104 septic shock patients and in 40 control patients. The volumes of control and septic shock patients were compared and the relationship between volume and outcome in intensive care was studied. The mean total volume of both adrenal glands was 7.2 {+-} 2.0 cm{sup 3} in control subjects and 13.3 {+-} 4.7 cm{sup 3} for total adrenal gland volume in septic shock patients (p < 0.0001). Measurement reproducibility was excellent with a concordance correlation coefficient value of 0.87. The increasing adrenal gland volume was associated with a higher rate of survival in intensive care. The present study reports that with semi-automated software, adrenal gland volume can be measured easily and reproducibly. Adrenal gland volume was found to be nearly double in sepsis compared with control patients. The absence of increased volume during sepsis would appear to be associated with a higher rate of mortality and may represent a prognosis factor which may help the clinician to guide their strategy. (orig.)

  9. Evaluating a satellite-based seasonal evapotranspiration product and identifying its relationship with other satellite-derived products and crop yield: A case study for Ethiopia

    Science.gov (United States)

    Tadesse, Tsegaye; Senay, Gabriel B.; Berhan, Getachew; Regassa, Teshome; Beyene, Shimelis

    2015-01-01

    Satellite-derived evapotranspiration anomalies and normalized difference vegetation index (NDVI) products from Moderate Resolution Imaging Spectroradiometer (MODIS) data are currently used for African agricultural drought monitoring and food security status assessment. In this study, a process to evaluate satellite-derived evapotranspiration (ETa) products with a geospatial statistical exploratory technique that uses NDVI, satellite-derived rainfall estimate (RFE), and crop yield data has been developed. The main goal of this study was to evaluate the ETa using the NDVI and RFE, and identify a relationship between the ETa and Ethiopia’s cereal crop (i.e., teff, sorghum, corn/maize, barley, and wheat) yields during the main rainy season. Since crop production is one of the main factors affecting food security, the evaluation of remote sensing-based seasonal ETa was done to identify the appropriateness of this tool as a proxy for monitoring vegetation condition in drought vulnerable and food insecure areas to support decision makers. The results of this study showed that the comparison between seasonal ETa and RFE produced strong correlation (R2 > 0.99) for all 41 crop growing zones in Ethiopia. The results of the spatial regression analyses of seasonal ETa and NDVI using Ordinary Least Squares and Geographically Weighted Regression showed relatively weak yearly spatial relationships (R2 cropping zones. However, for each individual crop zones, the correlation between NDVI and ETa ranged between 0.3 and 0.84 for about 44% of the cropping zones. Similarly, for each individual crop zones, the correlation (R2) between the seasonal ETa anomaly and de-trended cereal crop yield was between 0.4 and 0.82 for 76% (31 out of 41) of the crop growing zones. The preliminary results indicated that the ETa products have a good predictive potential for these 31 identified zones in Ethiopia. Decision makers may potentially use ETa products for monitoring cereal crop yields and

  10. A Case Study Examining Egypt, Nigeria, and Venezuela and their Flaring Behavior Utilizing VIIRS Satellite Data

    Science.gov (United States)

    Englander, J. G.; Austin, A. T.; Brandt, A. R.

    2016-12-01

    The need to quantify flaring by oil and gas fields is receiving more scrutiny, as there has been scientific and regulatory interest in quantifying the greenhouse gas (GHG) impact of oil and gas production. The National Oceanic and Atmospheric Administration (NOAA) has developed a method to track flaring activity using a Visible Infrared Imaging Radiometer Suite (VIIRS) satellite.[1] This reports data on the average size, power, and light intensity of each flare. However, outside of some small studies, the flaring intensity has generally been estimated at the country level.[2]While informative, country-level assessments cannot provide guidance about the sustainability of particular crude streams or products produced. In this work we generate detailed oil-field-level flaring intensities for a number of global oilfield operations. We do this by merging the VIIRS dataset with global oilfield atlases and other spatial data sources. Joining these datasets together with production data allows us to provide better estimates for the GHG intensity of flaring at the field level for these countries.[3]First, we compute flaring intensities at the field level for 75 global oil fields representing approximately 25% of global production. In addition, we examine in detail three oil producing countries known to have high rates of flaring: Egypt, Nigeria, and Venezuela. For these countries we compute the flaring rate for all fields in the country and explore within-and between-country variation. The countries' fields will be analyzed to determine the correlation of flare activity to a certain field type, crude type, region, or production method. [1] Cao, C. "Visible Infrared Imaging Radiometer Suite (VIIRS)." NOAA NPP VIIRS. NOAA, 2013. Web. 30 July 2016. [2] Elvidge, C. D. et al., "A Fifteen Year Record of Global Natural Gas Flaring Derived from Satellite Data," Energies, vol. 2, no. 3, pp. 595-622, Aug. 2009. [3] World Energy Atlas. 6th ed. London: Petroleum Economist, 2011. Print.

  11. The study of Be stars with the CoRoT satellite

    Science.gov (United States)

    Diago, P. D.; Gutierrez-Soto, J.; Fabregat, J.; Suso, J.; COROT Be Team

    2011-11-01

    The CoRoT space mission, launched in December 2006, is a spacecraft devoted to the study of the stellar interiors and the exo-planet search. Concerning the seismology of the Be stars, the presence of pulsations in late-type Be stars is still a matter of controversy. It constitutes an important issue to establish the relationship between non-radial pulsations and the mass-loss mechanism in Be stars. In this field, the CoRoT satellite is providing data with an unprecedent quality and precision that is confirming non-radial pulsations in Be stars. The CoRoT Be Team is an international collaboration composed by members from France, Spain, Brazil and Belgium and is in charge of the exploitation and analysis of the Be stars data. In this work we present the highlighted results of the observed Be stars by CoRoT and the future prospects of the CoRoT Be Team. These results include the detection of the Be star HD 49 330 during an outburst phase and the measurement of the change in the oscillation spectrum during this rare event. These observations gave insight into the nature of the explosion. It will help to solve a question that has been pending for years: are oscillations the cause of the outbursts? Moreover, for the first time, the CoRoT satellite has detected simultaneously the rotational and the pulsational frequencies for the Be star HD 50 209, which constitutes a proof of the presence of pulsations in the Be stars. %J Highlights of Spanish Astrophysics VI, Proceedings of the IX Scientific Meeting of the Spanish Astronomical Society (SEA), held in Madrid, September 13 - 17, 2010, Eds.: M. R. Zapatero Osorio, J. Gorgas, J. Maiz Apellaniz, J. R. Pardo, and A. Gil de Paz., p. 531-531

  12. Study on the detection of red-tide outbreaks using big satellite database

    Science.gov (United States)

    Son, Young Baek; Eun, Yoon Joo; Park, Kyongseok; Lee, Sanghwan; Lee, Ryong; Kim, Sang-Hyun; Yoo, Sinjae

    2014-11-01

    Satellite remote sensing has been successfully employed to monitor and detect the increasing incidence of harmful algal blooms (HABs) under various water conditions. In this study, to establish a comprehensive monitoring system of HAB outbreaks (particularly Cochlodinium polykrikoides blooms) in the southern coast of Korea (SCK), we tested the several proposed red-tide detection methods using SeaWiFS and MODIS ocean color data. Temporal and spatial information of red tide events from 2002 to 2013 were obtained from the National Fisheries Research and Development of Korea (NFRDI), which were matched with synchronously obtained satellite-derived ocean color data. The spectral characteristics of C. polykrikoides red tides were that increased phytoplankton absorption at 443 nm and pigment backscattering 555 nm resulted in a steeper slope between 488 and 555 nm with a hinge point at 488 (or 490) nm. On the other hand, non-red tide water, typically were presented by broader radiance spectra between the blue and green bands were associated with reduced pigment absorption and backscattering. The analysis of ocean color imageries that captured C. polykrikoides red tide blooms showed discolored waters with enhanced pigment concentrations, high chlorophyll, fluorescence, absorption at 443 nm. However, most red tide detection algorithms found a large number of false positive but only a small number of true positive areas. These proposed algorithms are not useful to distinguish true red tide water from complex non-red tide water. Our proposed method substantially reduces the false signal rate (false positive) from strong absorption at short wavelengths and provide a more reliable and robust detection of C. polykrikoides blooms in the SCK from the space.

  13. A Curriculum Activities Guide to Water Pollution and Environmental Studies, Volume II - Appendices.

    Science.gov (United States)

    Hershey, John T., Ed.; And Others

    This publication, Volume II of a two volume set of water pollution studies, contains seven appendices which support the studies. Appendix 1, Water Quality Parameters, consolidates the technical aspects of water quality including chemical, biological, computer program, and equipment information. Appendix 2, Implementation, outlines techniques…

  14. A Curriculum Activities Guide to Water Pollution and Environmental Studies, Volume II - Appendices.

    Science.gov (United States)

    Hershey, John T., Ed.; And Others

    This publication, Volume II of a two volume set of water pollution studies, contains seven appendices which support the studies. Appendix 1, Water Quality Parameters, consolidates the technical aspects of water quality including chemical, biological, computer program, and equipment information. Appendix 2, Implementation, outlines techniques…

  15. The determinations of remote sensing satellite data delivery service quality: A positivistic case study in Chinese context

    Science.gov (United States)

    Jin, Jiahua; Yan, Xiangbin; Tan, Qiaoqiao; Li, Yijun

    2014-03-01

    With the development of remote sensing technology, remote-sensing satellite has been widely used in many aspects of national construction. Big data with different standards and massive users with different needs, make the satellite data delivery service to be a complex giant system. How to deliver remote-sensing satellite data efficiently and effectively is a big challenge. Based on customer service theory, this paper proposes a hierarchy conceptual model for examining the determinations of remote-sensing satellite data delivery service quality in the Chinese context. Three main dimensions: service expectation, service perception and service environment, and 8 sub-dimensions are included in the model. Large amount of first-hand data on the remote-sensing satellite data delivery service have been obtained through field research, semi-structured questionnaire and focused interview. A positivist case study is conducted to validate and develop the proposed model, as well as to investigate the service status and related influence mechanisms. Findings from the analysis demonstrate the explanatory validity of the model, and provide potentially helpful insights for future practice.

  16. Physical activity predicts gray matter volume in late adulthood: the Cardiovascular Health Study.

    Science.gov (United States)

    Erickson, K I; Raji, C A; Lopez, O L; Becker, J T; Rosano, C; Newman, A B; Gach, H M; Thompson, P M; Ho, A J; Kuller, L H

    2010-10-19

    Physical activity (PA) has been hypothesized to spare gray matter volume in late adulthood, but longitudinal data testing an association has been lacking. Here we tested whether PA would be associated with greater gray matter volume after a 9-year follow-up, a threshold could be identified for the amount of walking necessary to spare gray matter volume, and greater gray matter volume associated with PA would be associated with a reduced risk for cognitive impairment 13 years after the PA evaluation. In 299 adults (mean age 78 years) from the Cardiovascular Health Cognition Study, we examined the association between gray matter volume, PA, and cognitive impairment. Physical activity was quantified as the number of blocks walked over 1 week. High-resolution brain scans were acquired 9 years after the PA assessment on cognitively normal adults. White matter hyperintensities, ventricular grade, and other health variables at baseline were used as covariates. Clinical adjudication for cognitive impairment occurred 13 years after baseline. Walking amounts ranged from 0 to 300 blocks (mean 56.3; SD 69.7). Greater PA predicted greater volumes of frontal, occipital, entorhinal, and hippocampal regions 9 years later. Walking 72 blocks was necessary to detect increased gray matter volume but walking more than 72 blocks did not spare additional volume. Greater gray matter volume with PA reduced the risk for cognitive impairment 2-fold. Greater amounts of walking are associated with greater gray matter volume, which is in turn associated with a reduced risk of cognitive impairment.

  17. The behaviour of satellite cells in response to exercise: what have we learned from human studies?

    DEFF Research Database (Denmark)

    Kadi, Fawzi; Olsen, Steen Schytte

    2005-01-01

    Understanding the complex role played by satellite cells in the adaptive response to exercise in human skeletal muscle has just begun. The development of reliable markers for the identification of satellite cell status (quiescence/activation/proliferation) is an important step towards the underst......Understanding the complex role played by satellite cells in the adaptive response to exercise in human skeletal muscle has just begun. The development of reliable markers for the identification of satellite cell status (quiescence/activation/proliferation) is an important step towards...... the understanding of satellite cell behaviour in exercised human muscles. It is hypothesised currently that exercise in humans can induce (1) the activation of satellite cells without proliferation, (2) proliferation and withdrawal from differentiation, (3) proliferation and differentiation to provide myonuclei...... and (4) proliferation and differentiation to generate new muscle fibres or to repair segmental fibre injuries. In humans, the satellite cell pool can increase as early as 4 days following a single bout of exercise and is maintained at higher level following several weeks of training. Cessation...

  18. Volume-outcome relation for acute appendicitis: evidence from a nationwide population-based study.

    Directory of Open Access Journals (Sweden)

    Po-Li Wei

    Full Text Available BACKGROUND: Although procedures like appendectomy have been studied extensively, the relative importance of each surgeon's surgical volume-to-ruptured appendicitis has not been explored. The purpose of this study was to investigate the rate of ruptured appendicitis by surgeon-volume groups as a measure of quality of care for appendicitis by using a nationwide population-based dataset. METHODS: We identified 65,339 first-time hospitalizations with a discharge diagnosis of acute appendicitis (International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM codes 540, 540.0, 540.1 and 540.9 between January 2007 and December 2009. We used "whether or not a patient had a perforated appendicitis" as the outcome measure. A conditional (fixed-effect logistic regression model was performed to explore the odds of perforated appendicitis among surgeon case volume groups. RESULTS: Patients treated by low-volume surgeons had significantly higher morbidity rates than those treated by high-volume (28.1% vs. 26.15, p<0.001 and very-high-volume surgeons (28.1% vs. 21.4%, p<0.001. After adjusting for surgeon practice location, and teaching status of practice hospital, and patient age, gender, and Charlson Comorbidity Index, and hospital acute appendicitis volume, patients treated by low-volume surgeons had significantly higher rates of perforated appendicitis than those treated by medium-volume surgeons (OR = 1.09, p<0.001, high-volume surgeons (OR = 1.16, p<0.001, or very-high-volume surgeons (OR = 1.54, p<0.001. CONCLUSION: Our study suggested that surgeon volume is an important factor with regard to the rate of ruptured appendicitis.

  19. Study of the turbulence in the central plasma sheet using the CLUSTER satellite data

    Science.gov (United States)

    Stepanova, M.; Arancibia Riveros, K.; Bosqued, J.; Antonova, E.

    2008-05-01

    Recent studies are shown that the turbulent processes in the space plasmas are very important. It includes the behavior of the plasma sheet plasma during geomagnetic substorms and storms. Study of the plasma turbulence in the central plasma sheet was made using the CLUSTER satellite mission data. For this studies we used the Cluster Ion Spectrometry experiment (CIS), and fluxgate magnetometer (FGM) data for studying fluctuations of the plasma bulk velocity and geomagnetic field fluctuations for different levels of geomagnetic activity and different locations inside the plasma sheet. Case studies for the orbits during quiet geomagnetic conditions, different phases of geomagnetic substroms and storms showed that the properties of plasma turbulence inside the sheet differ significantly for all afore mentioned cases. Variations in the probability distribution functions, flatness factors, local intermittency measure parameters, and eddy diffusion coefficients indicate that the turbulence increases significantly during substorm growth and expansion phases and decreases slowly to the initial level during the recovery phase. It became even stronger during the storm main phase.

  20. Forest fires detection in Indonesia using satellite Himawari-8 (case study: Sumatera and Kalimantan on august-october 2015)

    Science.gov (United States)

    Fatkhuroyan; Wati, Trinah; Panjaitan, Andersen

    2017-01-01

    Forest fires in Indonesia are serious problem affecting widely in material losses, health and environment. Himawari-8 as one of meteorological satellites with high resolution 0,5 km x 0,5 km can be used for forest fire monitoring and detection. Combination between 3, 4 and 6 channels using Sataid (Satellite Animation and Interactive Diagnosis) software will visualize forest fire in the study site. Monitoring which used Himawari-8 data on August, September and October 2015 can detect the distribution of smoke and the extents of forest fire in Sumatera and Kalimantan. The result showed the extent of forest fire can be identified for anticipation in the next step.

  1. Study to forecast and determine characteristics of world satellite communications market

    Science.gov (United States)

    Filep, R. T.; Schnapf, A.; Fordyce, S. W.

    1983-01-01

    The world commercial communications satellite market during the spring and summer of 1983 was examined and characteristics and forecasts of the market extending to the year 2000 were developed. Past, present and planned satellites were documented in relation to frequencies, procurement and launch dates, costs, transponders, and prime contractor. Characteristics of the market are outlined for the periods 1965 - 1985, 1986 - 1989, and 1990 - 2000. Market share forecasts, discussions of potential competitors in various world markets, and profiles of major communication satellite manufacturing and user countries are documented.

  2. Location studies of prostate volume measurement by using transrectal ultrasonography: Experimental study by self-produced prostate phantom

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Joon; Byeon, Il Kyun; Lee, Hoo Min [Dept. of Radiological Science, (Korea, Republic of); Kim, Yun Min; Kim, Hyeong Gyun [Dept. of Radiological Technology, Dongnam Health University, Suwon (Korea, Republic of)

    2015-12-15

    Accurate volume measurement of the prostate is a significant role in determining the result of diagnosis and treatment of benign prostate hyperplasia. The purpose of this study was to determine, when measuring prostate volume by TRUS, whether location is more accurately determined by transaxial or longitudinal scanning. With reference to the patient’s image, it was produced six prostate model. It compares the actual volume and the measurement volume, and find the optimal measurement position of each specific model. Prostate volume measured by TRUS closely correlates with prostate phantom volume. There was no significant difference(p = .156). To measure the accurate volume of prostate with focal protrusion, its length should be measured exclude the protrusions.

  3. Satellite orbit determination and gravity field recovery from satellite-to-satellite tracking

    Science.gov (United States)

    Wakker, K. F.; Ambrosius, B. A. C.; Leenman, H.

    1989-07-01

    Studies on satellite-to-satellite tracking (SST) with POPSAT (a geodetic satellite concept) and a ERS-class (Earth observation) satellite, a Satellite-to-Satellite Tracking (SST) gravity mission, and precise gravity field determination methods and mission requirements are reported. The first two studies primarily address the application of SST between the high altitude POPSAT and an ERS-class or GRM (Geopotential Research Mission) satellite to the orbit determination of the latter two satellites. Activities focussed on the determination of the tracking coverage of the lower altitude satellite by ground based tracking systems and by POPSAT, orbit determination error analysis and the determination of the surface forces acting on GRM. The third study surveys principles of SST, uncertainties of existing drag models, effects of direct luni-solar attraction and tides on orbit and the gravity gradient observable. Detailed ARISTOTELES (which replaced POPSAT) orbit determination error analyses were performed for various ground based tracking networks.

  4. Satellite and ship studies of phytoplankton along the west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Goes, J.I.; Gomes, H.; Kumar, A; Gouveia, A; Devassy, V.P.; Parulekar, A; Rao, L.V.G.

    AidEd. by a sequence of chlorophyll images from the Coastal Zone Color Scanner on board the Nimbus-7 satellite and extensive shipboard observations, a descriptive analysis of the factors influencing the distribution and production of phytoplankton...

  5. Exploration of satellite-derived data products for atmospheric turbulence studies

    CSIR Research Space (South Africa)

    Griffith, DJ

    2014-09-01

    Full Text Available layer. This has included all satellite data products that are relevant to the surface energy balance such as surface reflectance, temperature and emissivity. It was also important to identify active archive data services that can provide preprocessed...

  6. Qualification study of LiF flight crystals for the objective crystal spectrometer on the SPECTRUM-X-GAMMA satellite

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Rasmussen, I.; Schnopper, Herbert W.;

    1992-01-01

    The Objective Crystal Spectrometer (OXS) on the SPECTRUM-X-GAMMA satellite will carry these types of natural crystals LiF(220), Ge(111) and RAP(001). They will be used to study, among others, the H- and the He-like emission from the cosmically important elements Fe, S, Ar and O. More than 300 Li...

  7. Analytical study of pulsed laser irradiation on some materials used for photovoltaic cells on satellites

    Directory of Open Access Journals (Sweden)

    Afaf M. Abd El-Hameed

    2015-12-01

    Full Text Available The present research concerns on the study of laser-powered solar panels used for space applications. A mathematical model representing the laser effects on semiconductors has been developed. The temperature behavior and heat flow on the surface and through a slab has been studied after exposed to nano-second pulsed laser. The model is applied on two different types of common active semiconductor materials that used for photovoltaic cells fabrication as silicon (Si, and gallium arsenide (GaAs. These materials are used for receivers’ manufacture for laser beamed power in space. Various values of time are estimated to clarify the heat flow through the material sample and generated under the effects of pulsed laser irradiation. These effects are theoretically studied in order to determine the performance limits of the solar cells when they are powered by laser radiation during the satellite eclipse. Moreover, the obtained results are carried out to optimize conversion efficiency of photovoltaic cells and may be helpful to give more explanation for layout of the light-electricity space systems.

  8. Analytical study of pulsed laser irradiation on some materials used for photovoltaic cells on satellites

    Science.gov (United States)

    Abd El-Hameed, Afaf M.

    2015-12-01

    The present research concerns on the study of laser-powered solar panels used for space applications. A mathematical model representing the laser effects on semiconductors has been developed. The temperature behavior and heat flow on the surface and through a slab has been studied after exposed to nano-second pulsed laser. The model is applied on two different types of common active semiconductor materials that used for photovoltaic cells fabrication as silicon (Si), and gallium arsenide (GaAs). These materials are used for receivers' manufacture for laser beamed power in space. Various values of time are estimated to clarify the heat flow through the material sample and generated under the effects of pulsed laser irradiation. These effects are theoretically studied in order to determine the performance limits of the solar cells when they are powered by laser radiation during the satellite eclipse. Moreover, the obtained results are carried out to optimize conversion efficiency of photovoltaic cells and may be helpful to give more explanation for layout of the light-electricity space systems.

  9. Study of New Youth Initiatives in Apprenticeship. Interim Report. Volume 2: Site Visit Reports.

    Science.gov (United States)

    CSR, Inc., Washington, DC.

    This second volume of the interim report provides detailed case study reports on each of the eight Youth Apprenticeship Projects. (Volume 1, an overview of data from the site visits, is available separately as CE 032 791.) Discussion areas covered in each site visit report are local context/operational environment, administrative information,…

  10. A Study of Number Conservation With Tasks Which Vary in Length, Area and Volume. Final Report.

    Science.gov (United States)

    Taranto, Maria; Mermelstein, Egon

    The objective of this study was an attempt to clarify the nature of number conservation with number conservation tasks using variations in length, area, and volume. According to Piagetian theory, conservation is attained successively for number, length, area, and, finally, volume. It was hypothesized that success on the number conservation tasks…

  11. Online self-service processing system of ZY-3 satellite: a prospective study of image cloud services

    Science.gov (United States)

    Wang, Hongyan; Wang, Huabin; Shi, Shaoyu

    2015-12-01

    The strong demands for satellite images are increasing not only in professional fields, but also in the non-professionals. But the online map services with up-to-date satellite images can serve few demands. One challenge is how to provide online processing service, which need to handle real-time online data-intensive geospatial computation and visualization. Under the background of the development of cloud computing technology, the problem can be figured out partly. The other challenge is how to implement user-customized online processing without professional background and knowledge. An online self-service processing system of ZY-3 Satellite images is designed to implement an on-demand service mode in this paper. It will work with only some simple parameters being set up for the non-professionals without having to care about the specific processing steps. And the professionals can assemble the basic processing services to a service chain, which can work out a more complex processing and a better result. This intelligent self-service online system for satellite images processing, which is called the prototype of satellite image cloud service in this paper, is accelerated under the development of cloud computing technology and researches on data-intensive computing. To realize the goal, the service mode and framework of the online self-service processing system of ZY-3 Satellite images are figured out in this paper. The details of key technologies are also discussed, including user space virtualization management, algorithm-level parallel image processing, image service chain construction, etc. And the experimental system is built up as a prospective study of image cloud services.

  12. Study of Lau fringes generated by a photorefractive volume grating

    Science.gov (United States)

    Forte, Gustavo; Tebaldi, Myrian; Bolognini, Nestor

    2017-08-01

    In this work the Lau fringes generated by using a combination of an amplitude grating and a photorefractive volume phase grating is theoretically and experimentally analyzed. A model based on the path integral formalism to calculate the patterns intensity is employed. We show that the Lau pattern behavior is governed by the output pupil diameter of the imaging recording system, the DC external electric field and the crystal thickness. The introduction of a phase modulation that gathers the previously mentioned parameters allows determining the condition to optimize the fringe visibility. In this case, the visibility maintains a sinusoidal dependence as it happened with planar grating experiments. The experimental results confirm the theoretical model proposed.

  13. Commingled uranium-tailings study. Volume II. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-06-30

    Public Law 96-540, Section 213, directs the Secretary of Energy to develop a plan for a cooperative program to provide assistance in the stabilization and management of defense-related uranium mill tailings commingled with other tailings. In developing the plan, the Secretary is further directed to: (1) establish the amount and condition of tailings generated under federal contracts; (2) examine appropriate methodologies for establishing the extent of federal assistance; and (3) consult with the owners and operators of each site. This technical report summarizes US Department of Energy (DOE) and contractor activities in pursuit of items (1), (2), and (3) above. Recommendations regarding policy and a cooperative plan for federal assistance are under separate cover as Volume I.

  14. ICPP tank farm closure study. Volume 2: Engineering design files

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    Volume 2 contains the following topical sections: Tank farm heel flushing/pH adjustment; Grouting experiments for immobilization of tank farm heel; Savannah River high level waste tank 20 closure; Tank farm closure information; Clean closure of tank farm; Remediation issues; Remote demolition techniques; Decision concerning EIS for debris treatment facility; CERCLA/RCRA issues; Area of contamination determination; Containment building of debris treatment facility; Double containment issues; Characterization costs; Packaging and disposal options for the waste resulting from the total removal of the tank farm; Take-off calculations for the total removal of soils and structures at the tank farm; Vessel off-gas systems; Jet-grouted polymer and subsurface walls; Exposure calculations for total removal of tank farm; Recommended instrumentation during retrieval operations; High level waste tank concrete encasement evaluation; Recommended heavy equipment and sizing equipment for total removal activities; Tank buoyancy constraints; Grout and concrete formulas for tank heel solidification; Tank heel pH requirements; Tank cooling water; Evaluation of conservatism of vehicle loading on vaults; Typical vault dimensions and approximately tank and vault void volumes; Radiological concerns for temporary vessel off-gas system; Flushing calculations for tank heels; Grout lift depth analysis; Decontamination solution for waste transfer piping; Grout lift determination for filling tank and vault voids; sprung structure vendor data; Grout flow properties through a 2--4 inch pipe; Tank farm load limitations; NRC low level waste grout; Project data sheet calculations; Dose rates for tank farm closure tasks; Exposure and shielding calculations for grout lines; TFF radionuclide release rates; Documentation of the clean closure of a system with listed waste discharge; and Documentation of the ORNL method of radionuclide concentrations in tanks.

  15. The small satellite NINA-MITA to study galactic and solar cosmic rays in low-altitude polar orbit

    Science.gov (United States)

    Furano, G.; Bidoli, V.; Casolino, M.; de Pascale, M. P.; Iannucci, A.; Morselli, A.; Picozza, P.; Reali, E.; Sparvoli, R.; Bakaldin, A.; Galper, A.; Koldashov, M.; Korotkov, M.; Leonov, A.; Mikhailov, V.; Murashov, A.; Voronov, S.; Mazzenga, G.; Ricci, M.; Castellini, G.; Barbiellini, M.; Boezio, M.; Bonvicini, V.; Cirami, R.; Vacchi, A.; Zampa, N.; Ambriola, M.; Bellotti, R.; Cafagna, F.; Ciacio, F.; Circella, M.; de Marzo, C.; Adriani, O.; Papini, P.; Piccardi, S.; Spillantini, P.

    The satellite MITA, carrying on board the scientific payload NINA-2, was launched on July the 15th, 2000 from the cosmodrome of Plesetsk (Russia) with a Cosmos-3M rocket. The satellite and the payload are currently operating within nominal parameters. NINA-2 is the first scientific payload for the technological flight of the Italian small satellite MITA. The detector used in this mission is identical to the one already flying on the Russian satellite Resurs-O1 n.4 in a 840-km sun-synchronous orbit, but makes use of the extensive computer and telemetry capabilities of MITA bus to improve the active data acquisition time. NINA physics objectives are to study cosmic nuclei from hydrogen to iron in the energy range between 10 MeV/n and 1 GeV/n during the years 2000-2003, that is the solar maximum period. The device is capable of charge identification up to iron with isotope sensitivity up to oxigen. The 87.3 degrees, 460 km altitude polar orbit allows investigations of cosmic rays of solar and galactic origin, so to study long and short term solar transient phenomena, and the study of the trapped radiation at higher geomagnetic cutoff.

  16. Oceanography from satellites

    Science.gov (United States)

    Wilson, W. S.

    1981-01-01

    It is pointed out that oceanographers have benefited from the space program mainly through the increased efficiency it has brought to ship operations. For example, the Transit navigation system has enabled oceanographers to compile detailed maps of sea-floor properties and to more accurately locate moored subsurface instrumentation. General descriptions are given of instruments used in satellite observations (altimeter, color scanner, infrared radiometer, microwave radiometer, scatterometer, synthetic aperture radar). It is pointed out that because of the large volume of data that satellite instruments generate, the development of algorithms for converting the data into a form expressed in geophysical units has become especially important.

  17. Relationships between lightning activity and various thundercloud parameters: satellite and modelling studies

    Science.gov (United States)

    Baker, M. B.; Blyth, A. M.; Christian, H. J.; Latham, J.; Miller, K. L.; Gadian, A. M.

    The lightning frequency model developed by Baker et al. [Baker, M.B., Christian, H.J., Latham, J., 1995. A computational study of the relationships linking lightning frequency and other thundercloud parameters, Q. J. R. Meteorol. Soc., 121, 1525-1548] has been refined and extended, in an effort to provide a more realistic framework from which to examine computationally the relationships that might exist between lightning frequency f (which is now being routinely measured from a satellite, using the NASA/MSFC Optical Transient Detector (OTD)) and a variety of cloud physical parameters. Specifically, superior or more comprehensive representations were utilised of: (1) glaciation via the Hallett-Mossop (H-M) process; (2) the updraught structure of the model cloud; (3) the liquid-water-content structure of the model cloud; (4) the role of the reversal temperature Trev in influencing lightning characteristics; (5) the critical breakdown field for lightning initiation; and (6) the electrical characteristics of the ice crystal anvil of the model cloud. Although our extended studies yielded some new insights into the problem, the basic pattern of relationships between f and the other parameters was very close to that reported by Baker et al. (1995). The more elaborate treatment of Trev restricted somewhat the range of conditions under which reverse-polarity lightning could be produced if the cloud glaciated via H-M, but confirmed the earlier conclusion that such lightning would not occur if the glaciation was of the Fletcher type. The computations yielded preliminary support for the hypothesis that satellite measurements of f might be used to determine values of the ice-content of cumulonimbus anvils: a parameter of climatological importance. The successful launch and continuing satisfactory functioning of the OTD [Christian, H.J., Goodman, S., 1992. Global observations of lightning from space, Proc. 9th Int. Conf. on Atmospheric Electricity, St. Petersburg, pp. 316

  18. Pineal gland volume in primary insomnia and healthy controls: a magnetic resonance imaging study.

    Science.gov (United States)

    Bumb, Jan M; Schilling, Claudia; Enning, Frank; Haddad, Leila; Paul, Franc; Lederbogen, Florian; Deuschle, Michael; Schredl, Michael; Nolte, Ingo

    2014-06-01

    Little is known about the relation between pineal volume and insomnia. Melatonin promotes sleep processes and, administered as a drug, it is suitable to improve primary and secondary sleep disorders in humans. Recent magnetic resonance imaging studies suggest that human plasma and saliva melatonin levels are partially determined by the pineal gland volume. This study compares the pineal volume in a group of patients with primary insomnia to a group of healthy people without sleep disturbance. Pineal gland volume (PGV) was measured on the basis of high-resolution 3 Tesla MRI (T1-magnetization prepared rapid gradient echo) in 23 patients and 27 controls, matched for age, gender and educational status. Volume measurements were performed conventionally by manual delineation of the pineal borders in multi-planar reconstructed images. Pineal gland volume was significantly smaller (P insomnia compared to healthy controls. Further studies are needed to clarify whether low pineal volume is the basis or the consequence of functional sleep changes to elucidate the molecular pathology for the pineal volume loss in primary insomnia.

  19. Comparative Study of Ground Measured, Satellite-Derived, and Estimated Global Solar Radiation Data in Nigeria

    Directory of Open Access Journals (Sweden)

    Boluwaji M. Olomiyesan

    2016-01-01

    Full Text Available In this study, the performance of three global solar radiation models and the accuracy of global solar radiation data derived from three sources were compared. Twenty-two years (1984–2005 of surface meteorological data consisting of monthly mean daily sunshine duration, minimum and maximum temperatures, and global solar radiation collected from the Nigerian Meteorological (NIMET Agency, Oshodi, Lagos, and the National Aeronautics Space Agency (NASA for three locations in North-Western region of Nigeria were used. A new model incorporating Garcia model into Angstrom-Prescott model was proposed for estimating global radiation in Nigeria. The performances of the models used were determined by using mean bias error (MBE, mean percentage error (MPE, root mean square error (RMSE, and coefficient of determination (R2. Based on the statistical error indices, the proposed model was found to have the best accuracy with the least RMSE values (0.376 for Sokoto, 0.463 for Kaduna, and 0.449 for Kano and highest coefficient of determination, R2 values of 0.922, 0.938, and 0.961 for Sokoto, Kano, and Kaduna, respectively. Also, the comparative study result indicates that the estimated global radiation from the proposed model has a better error range and fits the ground measured data better than the satellite-derived data.

  20. Study on the volcanic ash cloud with Feng Yun-3 meteorological satellite data

    Science.gov (United States)

    Gong, Cai-lan T.; Jiang, Shan; Hu, Yong; Meng, Peng

    2013-09-01

    Volcano eruption can produce a mass of volcanic ash floating in the air for a long period, which will seriously threaten the aerial planes safety, and cause the air pollution, it could do harm to people's living environment and their health. Take the Iceland Eyjafjallajokull volcano as an example which erupted in April to May 2010, the volcano ash cloud were derived with the visible and infrared scanning radiometer of FengYun-3(FY-3 VIRR) meteorological satellite data. The medium wave infrared (MWIR) and the thermal infrared split windows (THIR-SW) data were used separately. the MODIS THIR-SW data were also be used to retrieve ash cloud to test the results derived from FY-3 VIRR data. It showed that the MWIR was more applicable for the ash cloud retrieving than the THIR-SW with FY-3 VIRR data, and the threshold value should be adjusted to around negative 1 rather than 0 for VIRR THIR-SW data. And the threshold should be adjusted with the THIR-SW of FY-3. The ash cloud radiation and bright temperature(BT), spatial distribution characteristics were also analyzed quantitatively with the two channels data. The study could provide parameters for the prediction of volcanic ash cloud dispersion simulate. When the real temperature of lava flow were high enough, the sensor will show a false bright temperature, how to retrieve the real temperature of the higher lava flow is a problem need to be studied in the future.

  1. Real time deforestation detection using ann and satellite images the Amazon rainforest study case

    CERN Document Server

    Nunes Kehl, Thiago; Roberto Veronez, Maurício; Cesar Cazella, Silvio

    2015-01-01

    The foremost aim of the present study was the development of a tool to detect daily deforestation in the Amazon rainforest, using satellite images from the MODIS/TERRA sensor and Artificial Neural Networks. The developed tool provides parameterization of the configuration for the neural network training to enable us to select the best neural architecture to address the problem. The tool makes use of confusion matrices to determine the degree of success of the network. A spectrum-temporal analysis of the study area was done on 57 images from May 20 to July 15, 2003 using the trained neural network. The analysis enabled verification of quality of the implemented neural network classification and also aided in understanding the dynamics of deforestation in the Amazon rainforest, thereby highlighting the vast potential of neural networks for image classification. However, the complex task of detection of predatory actions at the beginning, i.e., generation of consistent alarms, instead of false alarms has not bee...

  2. Studying bio-thermal effects at and around MSW dumps using Satellite Remote Sensing and GIS.

    Science.gov (United States)

    Mahmood, Khalid; Batool, Syeda Adila; Chaudhry, Muhammad Nawaz

    2016-09-01

    Estimating negative impacts of MSW dumps on its surrounding environment is the key requirement for any remedial measures. This study has been undertaken to map bio-thermal effects of MSW dumping at and around dumping facilities (non-engineered) using satellite imagery for Faisalabad, Pakistan. Thirty images of Landsat 8 have been selected after validation for the accuracy of their observational details from April 2013 to October 2015. Land Surface Temperature (LST), NDVI, SAVI and MSAVI have been derived from these images through Digital Image Processing (DIP) and have been subjected to spatio-temporal analysis in GIS environment. MSW dump has been found with average temperature elevation of 4.3K and 2.78K from nearby agriculture land and urban settlement respectively. Vegetation health has been used as the bio-indicator of MSW effects and is implemented through NDVI, SAVI, MSAVI. Spatial analyses have been used to mark boundary of bio-thermally affected zone around dumped MSW and measure 700m. Seasonal fluctuations of elevated temperatures and boundary of the bio-thermally affected zones have also been discussed. Based on the direct relation found between vegetation vigor and the level of deterioration within the bio-thermally affected region, use of crops with heavy vigor is recommended to study MSW hazard influence using bio-indicators of vegetation health.

  3. A comparative study of self-consolidating concretes incorporating high-volume natural pozzolan or high-volume fly ash

    KAUST Repository

    Celik, Kemal

    2014-09-01

    The purpose of this study is to compare the effects of Portland cement replacement on the strength and durability of self-consolidating concretes (SSC). The two replacement materials used are high-volume natural pozzolan (HVNP), a Saudi Arabian aluminum-silica rich basaltic glass and high-volume Class-F fly ash (HVFAF), from Jim Bridger Power Plant, Wyoming, US. As an extension of the study, limestone filler (LF) is also used to replace Portland cement, alongside HVNP or HVFAF, forming ternary blends. Along with compressive strength tests, non-steady state chloride migration and gas permeability tests were performed, as durability indicators, on SCC specimens. The results were compared to two reference concretes; 100% ordinary Portland cement (OPC) and 85% OPC - 15% LF by mass. The HVNP and HVFAF concrete mixes showed strength and durability results comparable to those of the reference concretes; identifying that both can effectively be used to produce low-cost and environmental friendly SCC. © 2013 Elsevier Ltd. All rights reserved.

  4. Several thoughts for using new satellite remote sensing and global modeling for aerosol and cloud climate studies

    Science.gov (United States)

    Nakajima, Teruyuki; Hashimoto, Makiko; Takenaka, Hideaki; Goto, Daisuke; Oikawa, Eiji; Suzuki, Kentaroh; Uchida, Junya; Dai, Tie; Shi, Chong

    2017-04-01

    The rapid growth of satellite remote sensing technologies in the last two decades widened the utility of satellite data for understanding climate impacts of aerosols and clouds. The climate modeling community also has received the benefit of the earth observation and nowadays closed-collaboration of the two communities make us possible to challenge various applications for societal problems, such as for global warming and global-scale air pollution and others. I like to give several thoughts of new algorithm developments, model use of satellite data for climate impact studies and societal applications related with aerosols and clouds. Important issues are 1) Better aerosol detection and solar energy application using expanded observation ability of the third generation geostationary satellites, i.e. Himawari-8, GOES-R and future MTG, 2) Various observation functions by directional, polarimetric, and high resolution near-UV band by MISR, POLDER&PARASOL, GOSAT/CAI and future GOSAT2/CAI2, 3) Various applications of general purpose-imagers, MODIS, VIIRS and future GCOM-C/SGLI, and 4) Climate studies of aerosol and cloud stratification and convection with active and passive sensors, especially climate impact of BC aerosols using CLOUDSAT&CALIPSO and future Earth Explorer/EarthCARE.

  5. Semiautomatic regional segmentation to measure orbital fat volumes in thyroid-associated ophthalmopathy. A validation study.

    Science.gov (United States)

    Comerci, M; Elefante, A; Strianese, D; Senese, R; Bonavolontà, P; Alfano, B; Bonavolontà, B; Brunetti, A

    2013-08-01

    This study was designed to validate a novel semi-automated segmentation method to measure regional intra-orbital fat tissue volume in Graves' ophthalmopathy. Twenty-four orbits from 12 patients with Graves' ophthalmopathy, 24 orbits from 12 controls, ten orbits from five MRI study simulations and two orbits from a digital model were used. Following manual region of interest definition of the orbital volumes performed by two operators with different levels of expertise, an automated procedure calculated intra-orbital fat tissue volumes (global and regional, with automated definition of four quadrants). In patients with Graves' disease, clinical activity score and degree of exophthalmos were measured and correlated with intra-orbital fat volumes. Operator performance was evaluated and statistical analysis of the measurements was performed. Accurate intra-orbital fat volume measurements were obtained with coefficients of variation below 5%. The mean operator difference in total fat volume measurements was 0.56%. Patients had significantly higher intra-orbital fat volumes than controls (p<0.001 using Student's t test). Fat volumes and clinical score were significantly correlated (p<0.001). The semi-automated method described here can provide accurate, reproducible intra-orbital fat measurements with low inter-operator variation and good correlation with clinical data.

  6. Volume-Outcome Relation for Acute Appendicitis: Evidence from a Nationwide Population-Based Study

    Science.gov (United States)

    Wei, Po-Li; Liu, Shih-Ping; Keller, Joseph J.; Lin, Herng-Ching

    2012-01-01

    Background Although procedures like appendectomy have been studied extensively, the relative importance of each surgeon's surgical volume-to-ruptured appendicitis has not been explored. The purpose of this study was to investigate the rate of ruptured appendicitis by surgeon-volume groups as a measure of quality of care for appendicitis by using a nationwide population-based dataset. Methods We identified 65,339 first-time hospitalizations with a discharge diagnosis of acute appendicitis (International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes 540, 540.0, 540.1 and 540.9) between January 2007 and December 2009. We used “whether or not a patient had a perforated appendicitis” as the outcome measure. A conditional (fixed-effect) logistic regression model was performed to explore the odds of perforated appendicitis among surgeon case volume groups. Results Patients treated by low-volume surgeons had significantly higher morbidity rates than those treated by high-volume (28.1% vs. 26.15, pappendicitis volume, patients treated by low-volume surgeons had significantly higher rates of perforated appendicitis than those treated by medium-volume surgeons (OR = 1.09, pappendicitis. PMID:23300703

  7. Preface to the Special Issue on "Geophysical and Climate Change Studies in Tibet, Xinjiang, and Siberia (TibXS from Satellite Geodesy"

    Directory of Open Access Journals (Sweden)

    Cheinway Hwang

    2013-01-01

    Full Text Available This special issue publishes papers on recent results in geophysical and climate change studies over Tibet, Xinjiang and Siberia (TibXS based upon some of the key sensors used in satellite geodesy, including satellite gravimetric sensors (GRACE and GOCE, satellite altimeters (TOPEX, Jason-1 and -2, and ENVISAT, and Global Positioning System satellites. Results from ground- and airborne-based geodetic observations, notably those based on airborne gravimeter, superconducting gravimeter (SG and seismometers are also included in the special issue. In all, 22 papers were submitted for this special issue; 17 papers were accepted.

  8. Integration of environmental simulation models with satellite remote sensing and geographic information systems technologies: case studies

    Science.gov (United States)

    Steyaert, Louis T.; Loveland, Thomas R.; Brown, Jesslyn F.; Reed, Bradley C.

    1993-01-01

    Environmental modelers are testing and evaluating a prototype land cover characteristics database for the conterminous United States developed by the EROS Data Center of the U.S. Geological Survey and the University of Nebraska Center for Advanced Land Management Information Technologies. This database was developed from multi temporal, 1-kilometer advanced very high resolution radiometer (AVHRR) data for 1990 and various ancillary data sets such as elevation, ecological regions, and selected climatic normals. Several case studies using this database were analyzed to illustrate the integration of satellite remote sensing and geographic information systems technologies with land-atmosphere interactions models at a variety of spatial and temporal scales. The case studies are representative of contemporary environmental simulation modeling at local to regional levels in global change research, land and water resource management, and environmental simulation modeling at local to regional levels in global change research, land and water resource management and environmental risk assessment. The case studies feature land surface parameterizations for atmospheric mesoscale and global climate models; biogenic-hydrocarbons emissions models; distributed parameter watershed and other hydrological models; and various ecological models such as ecosystem, dynamics, biogeochemical cycles, ecotone variability, and equilibrium vegetation models. The case studies demonstrate the important of multi temporal AVHRR data to develop to develop and maintain a flexible, near-realtime land cover characteristics database. Moreover, such a flexible database is needed to derive various vegetation classification schemes, to aggregate data for nested models, to develop remote sensing algorithms, and to provide data on dynamic landscape characteristics. The case studies illustrate how such a database supports research on spatial heterogeneity, land use, sensitivity analysis, and scaling issues

  9. Energy study of railroad freight transportation. Volume 2. Industry description

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-08-01

    The United States railroad industry plays a key role in transporting materials to support our industrial economy. One of the oldest industries in the US, the railroads have developed over 150 years into their present physical and operational configuration. Energy conservation proposals to change industry facilities, equipment, or operating practices must be evaluated in terms of their cost impact. A current, comprehensive and accurate data baseline of railroad economic activity and energy consumption is presented. Descriptions of the history of railroad construction in the US and current equipment, facilities, and operation practices follow. Economic models that relate cost and energy of railroad service to the volume of railroad output and to physical and operational parameters are provided. The analyses and descriptions should provide not only an analytical baseline for evaluating the impact of proposed conservation measures, but they should also provide a measure of understanding of the system and its operations to analysts and policy makers who are involved in proposing, analyzing, and implementing such changes.

  10. Preliminary study on direct assimilation of cloud-affected satellite microwave brightness temperatures

    Science.gov (United States)

    Zhang, Sibo; Guan, Li

    2017-02-01

    Direct assimilation of cloud-affected microwave brightness temperatures from AMSU-A into the GSI three-dimensional variational (3D-Var) assimilation system is preliminarily studied in this paper. A combination of cloud microphysics parameters retrieved by the 1D-Var algorithm (including vertical profiles of cloud liquid water content, ice water content, and rain water content) and atmospheric state parameters from objective analysis fields of an NWP model are used as background fields. Three cloud microphysics parameters (cloud liquid water content, ice water content, and rain water content) are applied to the control variable. Typhoon Halong (2014) is selected as an example. The results show that direct assimilation of cloud-affected AMSU-A observations can effectively adjust the structure of large-scale temperature, humidity and wind analysis fields due to the assimilation of more AMSU-A observations in typhoon cloudy areas, especially typhoon spiral cloud belts. These adjustments, with temperatures increasing and humidities decreasing in the movement direction of the typhoon, bring the forecasted typhoon moving direction closer to its real path. The assimilation of cloud-affected satellite microwave brightness temperatures can provide better analysis fields that are more similar to the actual situation. Furthermore, typhoon prediction accuracy is improved using these assimilation analysis fields as the initial forecast fields in NWP models.

  11. Application of Satellite-Based Spectrally-Resolved Solar Radiation Data to PV Performance Studies

    Directory of Open Access Journals (Sweden)

    Ana Maria Gracia Amillo

    2015-04-01

    Full Text Available In recent years, satellite-based solar radiation data resolved in spectral bands have become available. This has for the first time made it possible to produce maps of the geographical variation in the solar spectrum. It also makes it possible to estimate the influence of these variations on the performance of photovoltaic (PV modules. Here, we present a study showing the magnitude of the spectral influence on PV performance over Europe and Africa. The method has been validated using measurements of a CdTe module in Ispra, Italy, showing that the method predicts the spectral influence to within ±2% on a monthly basis and 0.1% over a 19-month period. Application of the method to measured spectral responses of crystalline silicon, CdTe and single-junction amorphous silicon (a-Si modules shows that the spectral effect is smallest over desert areas for all module types, higher in temperate Europe and highest in tropical Africa, where CdTe modules would be expected to yield +6% and single- junction a-Si modules up to +10% more energy due to spectral effects. In contrast, the effect for crystalline silicon modules is less than ±1% in nearly all of Africa and Southern Europe, rising to +1% or +2% in Northern Europe.

  12. Effect of hospital volume on processes of breast cancer care: A National Cancer Data Base study.

    Science.gov (United States)

    Yen, Tina W F; Pezzin, Liliana E; Li, Jianing; Sparapani, Rodney; Laud, Purushuttom W; Nattinger, Ann B

    2017-05-15

    The purpose of this study was to examine variations in delivery of several breast cancer processes of care that are correlated with lower mortality and disease recurrence, and to determine the extent to which hospital volume explains this variation. Women who were diagnosed with stage I-III unilateral breast cancer between 2007 and 2011 were identified within the National Cancer Data Base. Multiple logistic regression models were developed to determine whether hospital volume was independently associated with each of 10 individual process of care measures addressing diagnosis and treatment, and 2 composite measures assessing appropriateness of systemic treatment (chemotherapy and hormonal therapy) and locoregional treatment (margin status and radiation therapy). Among 573,571 women treated at 1755 different hospitals, 38%, 51%, and 10% were treated at high-, medium-, and low-volume hospitals, respectively. On multivariate analysis controlling for patient sociodemographic characteristics, treatment year and geographic location, hospital volume was a significant predictor for cancer diagnosis by initial biopsy (medium volume: odds ratio [OR] = 1.15, 95% confidence interval [CI] = 1.05-1.25; high volume: OR = 1.30, 95% CI = 1.14-1.49), negative surgical margins (medium volume: OR = 1.15, 95% CI = 1.06-1.24; high volume: OR = 1.28, 95% CI = 1.13-1.44), and appropriate locoregional treatment (medium volume: OR = 1.12, 95% CI = 1.07-1.17; high volume: OR = 1.16, 95% CI = 1.09-1.24). Diagnosis of breast cancer before initial surgery, negative surgical margins and appropriate use of radiation therapy may partially explain the volume-survival relationship. Dissemination of these processes of care to a broader group of hospitals could potentially improve the overall quality of care and outcomes of breast cancer survivors. Cancer 2017;123:957-66. © 2016 American Cancer Society. © 2016 American Cancer Society.

  13. Correlation between annual volume of cystectomy, professional staffing, and outcomes: a statewide, population-based study.

    Science.gov (United States)

    Elting, Linda S; Pettaway, Curtis; Bekele, B Nebiyou; Grossman, H Barton; Cooksley, Catherine; Avritscher, Elenir B C; Saldin, Kamaldeen; Dinney, Colin P N

    2005-09-01

    The association between high procedure volume and lower perioperative mortality is well established among cancer patients who undergo cystectomy. However, to the authors' knowledge, the association between volume and perioperative complications has not been studied to date and hospital characteristics contributing to the volume-outcome correlation are unknown. In the current study, the authors studied these associations, emphasizing hospital factors that contribute to the volume-outcome correlation. Multiple-variable models of inpatient mortality and complications were developed among all 1302 bladder carcinoma patients who underwent cystectomy between January 1, 1999 and December 31, 2001 in all Texas hospitals. General estimating equations were used to adjust for clustering within the 133 hospitals. Data were obtained from hospital claims, the 2000 U.S. Census, and databases from the Center for Medicare and Medicaid Services and the American Hospital Association. Complications were reported to occur in 12% of patients, 2.2% of whom died. Mortality was higher in low-volume hospitals compared with high-volume hospitals (3.1% vs. 0.7%; P < 0.001); mortality in moderate-volume hospitals was reported to be intermediate (2.9%). After adjustment for advanced age and comorbid conditions, treatment in high-volume hospitals was associated with lower risks of mortality (odds ratio [OR] = 0.35; P = 0.02) and complications (OR = 0.53; P = 0.01). Hospitals with a high registered nurse-to-patient ratio also had a lower mortality risk (OR = 0.43; P = 0.04). Mortality after cystectomy was found to be significantly lower in high-volume hospitals, regardless of patient age. Referral to a hospital performing greater than 10 cystectomies annually is indicated for all patients. However, patients with poor access to a high-volume hospital may derive similar benefit from treatment at a hospital with a high-registered nurse-to-patient ratio. This finding requires further confirmation.

  14. Centriolar satellites

    DEFF Research Database (Denmark)

    Tollenaere, Maxim A X; Mailand, Niels; Bekker-Jensen, Simon

    2015-01-01

    Centriolar satellites are small, microscopically visible granules that cluster around centrosomes. These structures, which contain numerous proteins directly involved in centrosome maintenance, ciliogenesis, and neurogenesis, have traditionally been viewed as vehicles for protein trafficking...... highlight newly discovered regulatory mechanisms targeting centriolar satellites and their functional status, and we discuss how defects in centriolar satellite components are intimately linked to a wide spectrum of human diseases....

  15. Geosynchronous platform definition study. Volume 4, Part 1: Traffic analysis and system requirements for the baseline traffic model

    Science.gov (United States)

    1973-01-01

    The traffic analyses and system requirements data generated in the study resulted in the development of two traffic models; the baseline traffic model and the new traffic model. The baseline traffic model provides traceability between the numbers and types of geosynchronous missions considered in the study and the entire spectrum of missions foreseen in the total national space program. The information presented pertaining to the baseline traffic model includes: (1) definition of the baseline traffic model, including identification of specific geosynchronous missions and their payload delivery schedules through 1990; (2) Satellite location criteria, including the resulting distribution of the satellite population; (3) Geosynchronous orbit saturation analyses, including the effects of satellite physical proximity and potential electromagnetic interference; and (4) Platform system requirements analyses, including satellite and mission equipment descriptions, the options and limitations in grouping satellites, and on-orbit servicing criteria (both remotely controlled and man-attended).

  16. Satellite theory

    Science.gov (United States)

    Kozai, Y.

    1981-04-01

    The dynamical characteristics of the natural satellite of Mars, Jupiter, Saturn, Uranus and Neptune are analyzed on the basis of the solar tidal perturbation factor and the oblateness factor of the primary planet for each satellite. For the inner satellites, for which the value of the solar tidal factor is much smaller than the planetary oblateness factor, it is shown that the eccentricity and inclination of satellite orbits are generally very small and almost constant; several pairs of inner satellites are also found to exhibit commensurable mean motions, or secular accelerations in mean longitude. In the case of the outer satellites, for which solar perturbations are dominant, secular perturbations and long-period perturbations may be derived by the solution of equations of motion reduced to one degree of freedom. The existence of a few satellites, termed intermediary satellites, for which the solar tidal perturbation is on the order of the planetary oblateness factor, is also observed, and the pole of the orbital plane of the satellite is noted to execute a complex motion around the pole of the planet or the orbital plane of the planet.

  17. Flood modelling with global precipitation measurement (GPM) satellite rainfall data: a case study of Dehradun, Uttarakhand, India

    Science.gov (United States)

    Sai Krishna, V. V.; Dikshit, Anil Kumar; Pandey, Kamal

    2016-05-01

    Urban expansion, water bodies and climate change are inextricably linked with each other. The macro and micro level climate changes are leading to extreme precipitation events which have severe consequences on flooding in urban areas. Flood simulations shall be helpful in demarcation of flooded areas and effective flood planning and preparedness. The temporal availability of satellite rainfall data at varying spatial scale of 0.10 to 0.50 is helpful in near real time flood simulations. The present research aims at analysing stream flow and runoff to monitor flood condition using satellite rainfall data in a hydrologic model. The satellite rainfall data used in the research was NASA's Integrated Multi-satellite Retrievals for Global Precipitation Measurement (IMERG), which is available at 30 minutes temporal resolution. Landsat data was used for mapping the water bodies in the study area. Land use land cover (LULC) data was prepared using Landsat 8 data with maximum likelihood technique that was provided as an input to the HEC-HMS hydrological model. The research was applied to one of the urbanized cities of India, viz. Dehradun, which is the capital of Uttarakhand State. The research helped in identifying the flood vulnerability at the basin level on the basis of the runoff and various socio economic parameters using multi criteria analysis.

  18. Brain tissue volumes in the general population of the elderly: the AGES-Reykjavik study.

    Science.gov (United States)

    Sigurdsson, Sigurdur; Aspelund, Thor; Forsberg, Lars; Fredriksson, Jesper; Kjartansson, Olafur; Oskarsdottir, Bryndis; Jonsson, Palmi V; Eiriksdottir, Gudny; Harris, Tamara B; Zijdenbos, Alex; van Buchem, Mark A; Launer, Lenore J; Gudnason, Vilmundur

    2012-02-15

    Imaging studies have reported conflicting findings on how brain structure differs with age and sex. This may be explained by discrepancies and limitations in study population and study design. We report a study on brain tissue volumes in one of the largest cohorts of individuals studied to date of subjects with high mean age (mean ± standard deviation (SD) 76 ± 6 years). These analyses are based on magnetic resonance imaging (MRI) scans acquired at baseline on 4303 non-demented elderly, and 367 who had a second MRI, on average 2.5 ± 0.2 years later. Tissue segmentation was performed with an automatic image analysis pipeline. Total brain parenchymal (TBP) volume decreased with increasing age while there was an increase in white matter hyperintensities (WMH) in both sexes. A reduction in both normal white matter (NWM)- and gray matter (GM) volume contributed to the brain shrinkage. After adjusting for intra-cranial volume, women had larger brain volumes compared to men (3.32%, p < 0.001) for TBP volume in the cross-sectional analysis. The longitudinal analysis showed a significant age-sex interaction in TBP volume with a greater rate of annual change in men (-0.70%, 95%CI: -0.78% to -0.63%) than women (-0.55%, 95%CI: -0.61% to -0.49%). The annual change in the cross-sectional data was approximately 40% less than the annual change in the longitudinal data and did not show significant age-sex interaction. The findings indicate that the cross-sectional data underestimate the rate of change in tissue volumes with age as the longitudinal data show greater rate of change in tissue volumes with age for all tissues.

  19. A prospective study of OAR volume variations between two different treatment planning systems in radiotherapy

    Directory of Open Access Journals (Sweden)

    Bhudevi Soubhagya Kulkarni

    2015-09-01

    Full Text Available Purpose: It has been seen that there is a clinically significant variation in the volume calculated across different planning systems for the same digital imaging and communication (DICOM contours.The purpose of this study is to investigate the difference in volumes of organs at risk when the structure sets were exported from the Eclipse ((Palo Alto, USA Version 10.0 to XIO CMS (Electa, Crawley, UK Version 4.40.00 treatment planning system (TPS and identify how the differences occur. Methods: We prospectively analyzed the volumes of organs at risk from computerized tomography (CT data of 54 patients. Head and neck and brain tumors were taken for this study and contoured on Eclipse treatment planning system (TPS after importing images from CT. These contoured images were then exported using radiotherapy DICOM transfer facility to XIO CMS planning system and compared the contoured volumes with Eclipse TPS structured volumes. Results: Our analysis showed that the differences in calculated volumes of the contours for the patients between the two planning systems can be large. Mixed results are shown for different organs with the absolute volume difference ranging from -0.25 cc to 319.73 cc. These results clearly shown that the two TPS interprets the contours differently when calculating the volume, and there is a closer match with the theoretical calculated volumes with XIO CMS calculated volumes. Conclusion: Observed discrepancies were consistent between the two planning systems. This impact of contouring variability could play a role on plan quality metrics which is used as criteria for clinical trial protocol compliance.

  20. Identification of volume overload hospitalizations among hemodialysis patients using administrative claims: a validation study.

    Science.gov (United States)

    Assimon, Magdalene M; Nguyen, Thuy; Katsanos, Suzanne L; Brunelli, Steven M; Flythe, Jennifer E

    2016-11-11

    High rates of volume overload hospitalizations may indicate inadequate dialysis facility fluid management. Administrative claims databases are often used to study such outcomes, but these data are generated for billing purposes and may not capture clinical nuance. It is unknown if volume overload admissions can be correctly identified in administrative data and if a single claims-based definition for volume overload can be used across epidemiologic surveillance studies, observational studies of exposure-outcome associations and quality assessments. We conducted a validation study to assess the accuracy of claims-based definitions for volume overload hospitalizations among hemodialysis patients. Data were taken from a random sample of 315 adult hemodialysis patients admitted to University of North Carolina Hospitals from January 2010 through June 2013. Standardized chart reviews were conducted to clinically adjudicate the presence or absence of volume overload at hospital admission. Claims-based definitions were constructed from varying combinations of fluid-related ICD-9 discharge diagnosis codes including fluid overload, pulmonary edema, pleural effusion, and heart failure. Using clinically adjudicated volume overload hospitalizations as the reference standard, validity metrics and their 95 % confidence intervals (CIs) were estimated for each definition. Of the 315 hospital admissions, 77 (24.4 %) were clinically adjudicated as volume overload hospitalizations. The prevalence of claims-identified volume overload admissions varied across definitions, ranging from 1.6 to 37.1 %. When definitions were constructed with discharge diagnosis codes present in any billing position, volume overload hospitalizations defined by fluid overload, pleural effusion or heart failure diagnosis codes had the highest sensitivity, 81.8 % (95 % CI: 71.4 %, 89.7 %). Volume overload hospitalizations defined by pulmonary edema diagnosis codes had the highest specificity, 98.3 % (95

  1. Back Bay-Currituck Sound Data Report: Fish Studies, Volume IV

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This data report is the fourth and final volume of data and preliminary analysis of data on the cooperative study of the ecology of Back Bay, Virginia, and Currituck...

  2. COMPARATIVE EFFECTIVENESS OF AN ADJUSTABLE TRANSFEMORAL PROSTHETIC INTERFACE ACCOMMODATING VOLUME FLUCTUATION: CASE STUDY.

    Science.gov (United States)

    Kahle, Jason T; Klenow, Tyler D; Highsmith, M Jason

    2016-09-01

    The socket-limb interface is vital for functionality and provides stability and mobility for the amputee. Volume fluctuation can lead to compromised fit and function. Current socket technology does not accommodate for volume fluctuation. An adjustable interface may improve function and comfort by filling this technology gap. The purpose of this study was to compare the effectiveness of the standard of care (SOC) ischial ramus containment to an adjustable transfemoral prosthetic interface socket in the accommodation of volume fluctuation. A prospective experimental case study using repeated measures of subjective and performance outcome measures between socket conditions was employed. In the baseline volume condition, the adjustable socket improved subjective and performance measures 19% to 37% over SOC, whereas the two-minute walk test demonstrated equivalence. In the volume loss condition, the adjustable socket improved all subjective and performance measures 22% to 93%. All aggregated data improved 16% to 50% compared with the SOC. In simulated volume gain, the SOC socket failed, while the subject was able to complete the protocol using the adjustable socket. In this case study, the SOC socket was inferior to the comparative adjustable transfemoral amputation interface in subjective and performance outcomes. There is a lack of clinical trials and evidence comparing socket functional outcomes related to volume fluctuation.

  3. COMPARATIVE EFFECTIVENESS OF AN ADJUSTABLE TRANSFEMORAL PROSTHETIC INTERFACE ACCOMMODATING VOLUME FLUCTUATION: CASE STUDY

    Science.gov (United States)

    Kahle, Jason T.; Klenow, Tyler D.; Highsmith, M. Jason

    2016-01-01

    The socket-limb interface is vital for functionality and provides stability and mobility for the amputee. Volume fluctuation can lead to compromised fit and function. Current socket technology does not accommodate for volume fluctuation. An adjustable interface may improve function and comfort by filling this technology gap. The purpose of this study was to compare the effectiveness of the standard of care (SOC) ischial ramus containment to an adjustable transfemoral prosthetic interface socket in the accommodation of volume fluctuation. A prospective experimental case study using repeated measures of subjective and performance outcome measures between socket conditions was employed. In the baseline volume condition, the adjustable socket improved subjective and performance measures 19% to 37% over SOC, whereas the two-minute walk test demonstrated equivalence. In the volume loss condition, the adjustable socket improved all subjective and performance measures 22% to 93%. All aggregated data improved 16% to 50% compared with the SOC. In simulated volume gain, the SOC socket failed, while the subject was able to complete the protocol using the adjustable socket. In this case study, the SOC socket was inferior to the comparative adjustable transfemoral amputation interface in subjective and performance outcomes. There is a lack of clinical trials and evidence comparing socket functional outcomes related to volume fluctuation. PMID:28066526

  4. Erosion, Transportation, and Deposition on Outer Solar System Satellites: Landform Evolution Modeling Studies

    Science.gov (United States)

    Moore, Jeffrey Morgan; Howard, Alan D.; Schenk, Paul M.

    2013-01-01

    Mass movement and landform degradation reduces topographic relief by moving surface materials to a lower gravitational potential. In addition to the obvious role of gravity, abrasive mechanical erosion plays a role, often in combination with the lowering of cohesion, which allows disaggregation of the relief-forming material. The identification of specific landform types associated with mass movement and landform degradation provides information about local sediment particle size and abundance and transportation processes. Generally, mass movements can be classified in terms of the particle sizes of the transported material and the speed the material moved during transport. Most degradation on outer planet satellites appears consistent with sliding or slumping, impact erosion, and regolith evolution. Some satellites, such as Callisto and perhaps Hyperion and Iapetus, have an appearance that implies that some additional process is at work, most likely sublimation-driven landform modification and mass wasting. A variant on this process is thermally driven frost segregation as seen on all three icy Galilean satellites and perhaps elsewhere. Titan is unique among outer planet satellites in that Aeolian and fluvial processes also operate to erode, transport, and deposit material. We will evaluate the sequence and extent of various landform-modifying erosional and volatile redistribution processes that have shaped these icy satellites using a 3-D model that simulates the following surface and subsurface processes: 1) sublimation and re-condensation of volatiles; 2) development of refractory lag deposits; 3) disaggregation and downward sloughing of surficial material; 4) radiative heating/cooling of the surface (including reflection, emission, and shadowing by other surface elements); 5) thermal diffusion; and 6) vapor diffusion. The model will provide explicit simulations of landform development and thusly predicts the topographic and volatile evolution of the surface

  5. A study of respiratory rate, tidal volume, inspiratory capacity and inspiratory reserve volume in different trimesters of pregnancy

    Directory of Open Access Journals (Sweden)

    Anita Teli

    2013-01-01

    Full Text Available Background: The anatomical, physiological and biochemical adaptations in pregnancy are profound. Many of these changes begin soon after fertilization and continue throughout the gestation and changes in the respiratory system are part of the same process. However there is insufficient information regarding the changes in respiratory parameters in different trimesters of pregnancy. Aims: The aim of the study was designed to evaluate the pulmonary function tests in 1 st , 2 nd and 3 rd trimesters of pregnancy and compare them with non-pregnant control group. Materials and Methods: A cross-sectional study was carried in 200 healthy women in the age range of 19-35 years. The subjects were distributed in four groups, as control (non-pregnant group and 1 st , 2 nd and 3 rd trimester pregnant groups. Number of subjects in each group was 50. Respiratory parameters in control and study groups were recorded. Statistical Analysis: By ′Z ′ test. Results: There was gradual significant increase in respiratory rate in all trimesters of pregnancy. There was a gradual decrease in tidal volume in 1 st , 2 nd and 3 rd trimesters of pregnancy when compared to non pregnant women. There was significant decrease in Inspiratory Reserve Volume and Inspiratory Capacity. Conclusion: The changes in pulmonary function are attributed to major adaptations in the maternal respiratory system and are influenced by the mechanical pressure of enlarging gravid uterus, elevating the diaphragm and restricting the movements of lungs thus hampering the forceful expiration and also might be due to decline in alveolar Pco 2 caused by hyperventilation which acts as bronchoconstrictor; in addition to sensitization of respiratory center due to progesterone

  6. A comparative study of spherical and flat-Earth geopotential modeling at satellite elevations

    Science.gov (United States)

    Parrott, M. H.; Hinze, W. J.; Braile, L. W.

    1985-01-01

    Flat-Earth and spherical-Earth geopotential modeling of crustal anomaly sources at satellite elevations are compared by computing gravity and scalar magnetic anomalies perpendicular to the strike of variably dimensioned rectangular prisms at altitudes of 150, 300, and 450 km. Results indicate that the error caused by the flat-Earth approximation is less than 10% in most geometric conditions. Generally, error increase with larger and wider anomaly sources at higher altitudes. For most crustal source modeling applications at conventional satellite altitudes, flat-Earth modeling can be justified and is numerically efficient.

  7. Study of time-lapse processing for dynamic hydrologic conditions. [electronic satellite image analysis console for Earth Resources Technology Satellites imagery

    Science.gov (United States)

    Serebreny, S. M.; Evans, W. E.; Wiegman, E. J.

    1974-01-01

    The usefulness of dynamic display techniques in exploiting the repetitive nature of ERTS imagery was investigated. A specially designed Electronic Satellite Image Analysis Console (ESIAC) was developed and employed to process data for seven ERTS principal investigators studying dynamic hydrological conditions for diverse applications. These applications include measurement of snowfield extent and sediment plumes from estuary discharge, Playa Lake inventory, and monitoring of phreatophyte and other vegetation changes. The ESIAC provides facilities for storing registered image sequences in a magnetic video disc memory for subsequent recall, enhancement, and animated display in monochrome or color. The most unique feature of the system is the capability to time lapse the imagery and analytic displays of the imagery. Data products included quantitative measurements of distances and areas, binary thematic maps based on monospectral or multispectral decisions, radiance profiles, and movie loops. Applications of animation for uses other than creating time-lapse sequences are identified. Input to the ESIAC can be either digital or via photographic transparencies.

  8. Customer premise service study for 30/20 GHz satellite system

    Science.gov (United States)

    Milton, R. T.; Ross, D. P.; Harcar, A. R.; Freedenberg, P.; Schoen, D.

    1983-01-01

    Satellite systems in which the space segment operates in the 30/20 GHz frequency band are defined and compared as to their potential for providing various types of communications services to customer premises and the economic and technical feasibility of doing so. Technical tasks performed include: market postulation, definition of the ground segment, definition of the space segment, definition of the integrated satellite system, service costs for satellite systems, sensitivity analysis, and critical technology. Based on an analysis of market data, a sufficiently large market for services is projected so as to make the system economically viable. A large market, and hence a high capacity satellite system, is found to be necessary to minimize service costs, i.e., economy of scale is found to hold. The wide bandwidth expected to be available in the 30/20 GHz band, along with frequency reuse which further increases the effective system bandwidth, makes possible the high capacity system. Extensive ground networking is required in most systems to both connect users into the system and to interconnect Earth stations to provide spatial diversity. Earth station spatial diversity is found to be a cost effective means of compensating the large fading encountered in the 30/20 GHz operating band.

  9. Satellite Altimetry and GRACE Gravimetry for Studies of Annual Water Storage Variations in Bangladesh

    Directory of Open Access Journals (Sweden)

    Ole Andersen

    2008-01-01

    Full Text Available Four different data sources have been compared with respect to observations of the annual water storage variations in the region of Bangladesh. Data from satellite altimeters and river gauges estimates the variation in surface water storage in the major rivers of Bangladesh.

  10. Simultaneous optical and satellite observations of auroras in the mantle: Case study

    Science.gov (United States)

    Safargaleev, V. V.; Mitrofanov, V. M.; Roldugin, A. V.

    2016-11-01

    The all-sky camera data obtained in Barentsburg (Spitsbergen Archipelago) are compared with specific features of electron and ion precipitations on the DMSP F18 satellite during its flight within the camera field of view on December 15, 2012. Before arriving at the cusp from the mantle side, the satellite detects two outbursts of precipitating particles. The burst of mantle precipitations far from the cusp is observed simultaneously in both ionic and electronic components. In the ionosphere related to the satellite, no auroras are detected, which is likely due to the low intensity of the flux of precipitating electrons and their low energy (80 eV). Near the cusp, a more intensive burst of precipitations of higher-energy electrons (140 eV) is accompanied by an almost complete "locking" of ions. This burst of mantle precipitations is related to the faint luminous structure in the ionosphere. The ion locking is indicative of the accelerating potential difference in the force tube, which is based on the glowing region. The luminous structure is an element of the so-called "polewar moving auroral forms," which is related in the literature to the reconnection in the daytime magnetopause. The possible relation of the observed phenomena to the reconnected magnetic force tubes, which drift from the cusp in the antisolar direction, is also confirmed by the dispersion of ionic precipitations, i.e., an increase in ion energy as the satellite approaches to the cusp.

  11. NanoSAR – Case study of synthetic aperture radar for nano-satellites

    NARCIS (Netherlands)

    Engelen, S.; Oever, M. van den; Mahapatra, P.S.; Sundaramoorthy, P.P.; Gill, E.K.A.; Meijer, R.J.; Verhoeven, C.J.M.

    2012-01-01

    Nano-satellites have a cost advantage due to their low mass and usage of commercial-off-the-shelf technologies. However, the low mass also restricts the functionality of a nano-satellite’s payload. Typically, this would imply instruments with very low to low resolution and accuracy, essentially

  12. Conjunction of tail satellites for substorm study: ISTP event of 1997 January 2

    DEFF Research Database (Denmark)

    Lui, A.T.Y.; Liou, K.; Newell, P.T.;

    2000-01-01

    dipolarization at Geotail and highly fluctuating magnetic field (mostly northward B-z) at IMP-8. Observations for this substorm showed no indication of mid-tail activities occurring prior to auroral brightening for both onset and intensification even though the satellites observed activities subsequently. Close...

  13. Initializing HYSPLIT with satellite observations of volcanic ash: A case study of the 2008 Kasatochi eruption

    Science.gov (United States)

    Crawford, Alice M.; Stunder, Barbara J. B.; Ngan, Fong; Pavolonis, Michael J.

    2016-09-01

    The current work focuses on improving volcanic ash forecasts by integrating satellite observations of ash into the Lagrangian transport and dispersion model, HYSPLIT. The accuracy of HYSPLIT output is dependent on the accuracy of the initialization: the initial position, size distribution, and amount of ash as a function of time. Satellite observations from passive infrared, IR, sensors are used both to construct the initialization term and for verification. Space-based lidar observations are used for further verification. We compare model output produced using different initializations for the 2008 eruption of Kasatochi in the Aleutian Islands. Simple source terms, such as a uniform vertical line or cylindrical source above the vent, are compared to initializations derived from satellite measurements of position, mass loading, effective radius, and height of the downwind ash cloud. Using satellite measurements of column mass loading of ash to constrain the source term produces better long-term predictions than using an empirical equation relating mass eruption rate and plume height above the vent. Even though some quantities, such as the cloud thickness, must be estimated, initializations which release particles at the position of the observed ash cloud produce model output which is comparable to or better than the model output produced with source terms located above and around the vent. Space-based lidar data, passive IR retrievals of ash cloud top height, and model output agree well with each other, and all suggest that the Kasatochi ash cloud evolved into a complex three-dimensional structure.

  14. Study on networking issues of medium earth orbit satellite communications systems

    Science.gov (United States)

    Araki, Noriyuki; Shinonaga, Hideyuki; Ito, Yasuhiko

    1993-01-01

    Two networking issues of communications systems with medium earth orbit (MEO) satellites, namely network architectures and location determination and registration methods for hand-held terminals, are investigated in this paper. For network architecture, five candidate architectures are considered and evaluated in terms of signaling traffic. For location determination and registration, two methods are discussed and evaluated.

  15. Fractional calculus approach to study temperature distribution within a spinning satellite

    Directory of Open Access Journals (Sweden)

    Jyotindra C. Prajapati

    2016-09-01

    Full Text Available This paper deals with the temperature distribution within spinning satellites and problem is formulated in terms of fractional differential equation. Applying fractional calculus approach, solution of this equation is obtained in terms of Wright generalized hypergeometric function, a generalization of exponential function.

  16. Quest for learning: A study of teachers' perceptions of the Satellite Education and Environmental Research Program

    Science.gov (United States)

    Ahern, Kathryn A.

    The purpose of this study was to examine the perceptions of teachers who participated in the Satellite Education and Environmental Research (SEER) Program Water Project, a curriculum design course developed at the University of Nebraska-Lincoln. The distance education course was a complex intervention which used the Nebraska Mathematics and Science Initiative's Model Program criteria for inquiry-based curriculum. Teachers formed communities of inquiry, experienced scientific inquiry processes, integrated different disciplines to create new thematic science curricula, and were encouraged to employ innovative pedagogical practices. National Science Education Standards and Nebraska Mathematics and Science Frameworks were consulted to develop important science process skills and concepts. Multicultural science education was addressed through investigation of local water issues. Teachers were encouraged to form community partnerships, supported with testing materials for conducting scientific research, and expected to use computer technology. Grounded theory was used to examine interviews of 26 participants for their perceptions of the effects of the intervention on their teaching strategies. The self-reports were triangulated through the external evaluation report, classroom artifacts, and a limited number of observations of classroom and field activities. Open coding was used to categorize the interview responses and to propose relationships among them. The central phenomenon that emerged from the axial and select coding was the changed focus: teaching science more thematically. Three theoretical propositions were posed to guide further inquiry: (1) teachers need opportunities and resources to experience science as an authentic, tenable, and realistic process if they are to develop curriculum and focus classroom activities on scientific inquiry; (2) autonomous learning communities must be fostered at downlink sites if distance learning experiences are to affect

  17. A DEEP STUDY OF THE DWARF SATELLITES ANDROMEDA XXVIII AND ANDROMEDA XXIX

    Energy Technology Data Exchange (ETDEWEB)

    Slater, Colin T.; Bell, Eric F. [Department of Astronomy, University of Michigan, 1085 S. University Ave., Ann Arbor, MI 48109 (United States); Martin, Nicolas F. [Observatoire astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l’Université, F-67000 Strasbourg (France); Tollerud, Erik J.; Ho, Nhung [Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 06510 (United States)

    2015-06-20

    We present the results of a deep study of the isolated dwarf galaxies Andromeda XXVIII and Andromeda XXIX with Gemini/GMOS and Keck/DEIMOS. Both galaxies are shown to host old, metal-poor stellar populations with no detectable recent star formation, conclusively identifying both of them as dwarf spheroidal galaxies (dSphs). And XXVIII exhibits a complex horizontal branch morphology, which is suggestive of metallicity enrichment and thus an extended period of star formation in the past. Decomposing the horizontal branch into blue (metal-poor, assumed to be older) and red (relatively more metal-rich, assumed to be younger) populations shows that the metal-rich are also more spatially concentrated in the center of the galaxy. We use spectroscopic measurements of the calcium triplet, combined with the improved precision of the Gemini photometry, to measure the metallicity of the galaxies, confirming the metallicity spread and showing that they both lie on the luminosity–metallicity relation for dwarf satellites. Taken together, the galaxies exhibit largely typical properties for dSphs despite their significant distances from M31. These dwarfs thus place particularly significant constraints on models of dSph formation involving environmental processes such as tidal or ram pressure stripping. Such models must be able to completely transform the two galaxies into dSphs in no more than two pericentric passages around M31, while maintaining a significant stellar population gradient. Reproducing these features is a prime requirement for models of dSph formation to demonstrate not just the plausibility of environmental transformation but the capability of accurately recreating real dSphs.

  18. Photometric and spectroscopic study of the ultra-faint Milky Way satellite Pegasus III

    Science.gov (United States)

    Kim, Dongwon; Jerjen, Helmut; Geha, Marla C.; Chiti, Anirudh; Milone, Antonino; Da Costa, Gary S.; Mackey, Dougal; Frebel, Anna; Conn, Blair

    2017-01-01

    Pegasus III (Peg III) is one of the few known ultra-faint dwarf (UFD) satellite galaxies in the outer halo (R >150 kpc) of the Milky Way (MW). We present results from a recent study of Peg III using Magellan/IMACS and Keck/DEIMOS. Our newly-measured structural parameters confirm that Peg III is large (rh = 53±14pc), elongated (∈ = 0.38+0.22-0.38 ), and faint (MV=-3.4±0.4 mag) — indicative of its nature as a dwarf rather than a globular cluster. In the color-magnitude diagram, Peg III is well described by an old (>12Gyr) and metal-poor ([Fe/H]measurements of individual stars, we identify seven kinematic members of Peg III. The Ca II triplet lines of the brightest members verify that Peg III indeed contains stars with metallicity as low as [Fe/H]=-2.55±0.15 dex. The systemic velocity and velocity dispersion of Peg III are -222.9±2.6 km/s and 5.4+3.0-2.5 km/s, respectively. The inferred dynamical mass within the half-light radius of 1.4+3.0-1.1×106M⊙, and the mass-to-light ratio of M/LV = 1470+5660-1240M⊙/L⊙ provide further evidence that Peg III is a bona fide UFD. Peg III and another distant UFD Pisces II lie relatively close to each other (△dspatial=43±19 kpc) and share similar systemic radial velocities (△vGSR=12.3±3.7 km/s), which suggests that they may share a common origin.

  19. A Deep Study of the Dwarf Satellites Andromeda XXVIII and Andromeda XXIX

    Science.gov (United States)

    Slater, Colin T.; Bell, Eric F.; Martin, Nicolas F.; Tollerud, Erik J.; Ho, Nhung

    2015-06-01

    We present the results of a deep study of the isolated dwarf galaxies Andromeda XXVIII and Andromeda XXIX with Gemini/GMOS and Keck/DEIMOS. Both galaxies are shown to host old, metal-poor stellar populations with no detectable recent star formation, conclusively identifying both of them as dwarf spheroidal galaxies (dSphs). And XXVIII exhibits a complex horizontal branch morphology, which is suggestive of metallicity enrichment and thus an extended period of star formation in the past. Decomposing the horizontal branch into blue (metal-poor, assumed to be older) and red (relatively more metal-rich, assumed to be younger) populations shows that the metal-rich are also more spatially concentrated in the center of the galaxy. We use spectroscopic measurements of the calcium triplet, combined with the improved precision of the Gemini photometry, to measure the metallicity of the galaxies, confirming the metallicity spread and showing that they both lie on the luminosity-metallicity relation for dwarf satellites. Taken together, the galaxies exhibit largely typical properties for dSphs despite their significant distances from M31. These dwarfs thus place particularly significant constraints on models of dSph formation involving environmental processes such as tidal or ram pressure stripping. Such models must be able to completely transform the two galaxies into dSphs in no more than two pericentric passages around M31, while maintaining a significant stellar population gradient. Reproducing these features is a prime requirement for models of dSph formation to demonstrate not just the plausibility of environmental transformation but the capability of accurately recreating real dSphs.

  20. Association between amygdala volume and anxiety level: magnetic resonance imaging (MRI) study in autistic children.

    Science.gov (United States)

    Juranek, Jenifer; Filipek, Pauline A; Berenji, Gholam R; Modahl, Charlotte; Osann, Kathryn; Spence, M Anne

    2006-12-01

    Our objective was to evaluate brain-behavior relationships between amygdala volume and anxious/depressed scores on the Child Behavior Checklist in a well-characterized population of autistic children. Volumes for the amygdala, hippocampus, and whole brain were obtained from three-dimensional magnetic resonance images (MRIs) captured from 42 children who met the criteria for autistic disorder. Anxious/depressed symptoms were assessed in these children by the Anxious/Depressed subscale of the Child Behavior Checklist. To investigate the association between anxious/depressed scores on the Child Behavior Checklist and amygdala volume, data were analyzed using linear regression methods with Pearson correlation coefficients. A multivariate model was used to adjust for potential covariates associated with amygdala volume, including age at MRI and total brain size. We found that anxious/depressed symptoms were significantly correlated with increased total amygdala volume (r = .386, P = .012) and right amygdala volume (r = .469, P = .002). The correlation between anxious/depressed symptoms and left amygdala volume did not reach statistical significance (r = .249, P = .112). Child Behavior Checklist anxious/depressed scores were found to be a significant predictor of amygdala total (P = .014) and right amygdala (P = .002) volumes. In conclusion, we have identified a significant brain-behavior relationship between amygdala volume and anxious/depressed scores on the Child Behavior Checklist in our autistic cohort. This specific relationship has not been reported in autism. However, the existing literature on human psychiatry and behavior supports our reported evidence for a neurobiologic relationship between symptoms of anxiety and depression with amygdala structure and function. Our results highlight the importance of characterizing comorbid psychiatric symptomatology in autism. The abundance of inconsistent findings in the published literature on autism might reflect

  1. Ornamental Horticulture. Course of Study Outlines. 1975 Edition. Volume XXX.

    Science.gov (United States)

    Wilson, Aubry

    These courses of study in ornamental horticulture for secondary and adult technical education levels are based on a 1972 Rutgers University study and are designed to accomodate occupational needs in the field of ornamental horticulture. Job titles emphasized at the secondary level are caretaker, nurserymen, flower grower, and flower salesperson;…

  2. Industrial Education Ventilation Study. Volume 1: Final Report.

    Science.gov (United States)

    Stanley Associates, Edmonton (Alberta).

    A study assessed aspects of ventilation in industrial education facilities in selected junior and senior highs schools in Alberta (Canada). This report describes the purpose of the study and the four test methods used to acquire school specific information. Also discussed are (1) the results of the instructors' perception survey, the ventilation…

  3. SEASAT economic assessment. Volume 3: Offshore oil and natural gas industry case study and generalization

    Science.gov (United States)

    1975-01-01

    The economic benefits of improved ocean condition, weather and ice forecasts by SEASAT satellites to the exploration, development and production of oil and natural gas in the offshore regions are considered. The results of case studies which investigate the effects of forecast accuracy on offshore operations in the North Sea, the Celtic Sea, and the Gulf of Mexico are reported. A methodology for generalizing the results to other geographic regions of offshore oil and natural gas exploration and development is described.

  4. Conceptual design and systems analysis of photovoltaic systems. Volume II. Study results. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kirpich, A.

    1977-03-19

    This investigation of terrestrial PV systems considered the technical and economic feasibility for systems in three size categories: a small system of about 12 kW peak output for on-site residential use; a large 1500 MW central power plant contributing to the bulk energy of a utility system power grid; and an intermediate size system of about 250 kW for use on public or commercial buildings. In each category, conceptual designs were developed, performance was analyzed for a range of climatic regions, economic analyses were performed, and assessments were made of pertinent institutional issues. The report consists of three volumes. Volume I contains a Study Summary of the major study results. This volume contains the detailed results pertaining to on-site residential photovoltaic systems, central power plant photovoltaic systems, and intermediate size systems applied to commercial and public buildings. Volume III contains supporting appendix material. (WHK)

  5. Wilderness Study Report : Volume VI : Kenai National Moose Range

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In order to conform to the Wilderness Act of 1964, a study was conducted by the Bureau of Sport Fisheries and Wildlife personnel to ascertain which of the Kenai...

  6. Nevada potential repository preliminary transportation strategy Study 2. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The objectives of this study were to build on the findings of the Nevada Potential Repository Preliminary Transportation Strategy Study 1 (CRWMS M&O 1995b), and to provide additional information for input to the repository environmental impact statement (EIS) process. In addition, this study supported the future selection of a preferred rail corridor and/or heavy haul route based on defensible data, methods, and analyses. Study research did not consider proposed legislation. Planning was conducted according to the Civilian Radioactive Waste Management Program Plan (DOE 1994a). The specific objectives of Study 2 were to: eliminate or reduce data gaps, inconsistencies, and uncertainties, and strengthen the analysis performed in Study 1; develop a preliminary list of rail route evaluation criteria that could be used to solicit input from stakeholders during scoping meetings. The evaluation criteria will be revised based on comments received during scoping; restrict and refine the width of the four rail corridors identified in Study 1 to five miles or less, based on land use constraints and engineering criteria identified and established in Study 2; evaluate national-level effects of routing spent nuclear fuel and high-level waste to the four identified branch lines, including the effects of routing through or avoiding Las Vegas; continue to gather published land use information and environmental data to support the repository EIS; continue to evaluate heavy haul truck transport over three existing routes as an alternative to rail and provide sufficient information to support the repository EIS process; and evaluate secondary uses for rail (passenger use, repository construction, shared use).

  7. Strategic Studies Quarterly, Volume 4, Number 3, Fall 2010

    Science.gov (United States)

    2010-01-01

    1948-12 May 1949)—perhaps the best- known relief operation in American history—the Air Force provided vital S QUARTER! > • FAU 2010 \\_ •’ I food...and personnel to begin performing at least the first two functions immediately. [28] STRATEGIC STUDIES QUARTERLY • FAU 2010 Guidelines for Nation...assistance, as measured as a share of GDP, than more-settled societies. Whereas most STRATEGIC STUDIES QUARTERLY • FAU 2010 [35] James F. Dobbins

  8. A study of possible sea state information in the sample and hold gate statistics for the GEOS-3 satellite altimeter

    Science.gov (United States)

    Wells, W. T.; Borman, K. L.; Mitchell, R. D.; Dempsey, D. J.

    1979-01-01

    The statistical variations in the sample gate outputs of the GEOS-3 satellite altimeter were studied for possible sea state information. After examination of a large number of statistical characteristics of the altimeter waveforms, it was found that the best sea predictor for H-1/3 in the range of 0 to 3 meters was the 75th percentile of sample and hold gate number 11.

  9. Site locality identification study: Hanford Site. Volume II. Data cataloging

    Energy Technology Data Exchange (ETDEWEB)

    1980-07-01

    Data compilation and cataloging for the candidate site locality identification study were conducted in order to provide a retrievable data cataloging system for the present siting study and future site evaluation and licensng processes. This task occurred concurrently with and also independently of other tasks of the candidate site locality identification study. Work in this task provided the data utilized primarily in the development and application of screening and ranking processes to identify candidate site localities on the Hanford Site. The overall approach included two steps: (1) data acquisition and screening; and (2) data compilation and cataloging. Data acquisition and screening formed the basis for preliminary review of data sources with respect to their probable utilization in the candidate site locality identification study and review with respect to the level of completeness and detail of the data. The important working assumption was that the data to be used in the study be based on existing and available published and unpublished literature. The data compilation and cataloging provided the basic product of the Task; a retrievable data cataloging system in the form of an annotated reference list and key word index and an index of compiled data. The annotated reference list and key word index are cross referenced and can be used to trace and retrieve the data sources utilized in the candidate site locality identification study.

  10. COMPARATIVE EFFECTIVENESS OF AN ADJUSTABLE TRANSFEMORAL PROSTHETIC INTERFACE ACCOMMODATING VOLUME FLUCTUATION: CASE STUDY

    OpenAIRE

    Kahle, Jason T.; Klenow, Tyler D.; Highsmith, M. Jason

    2016-01-01

    The socket-limb interface is vital for functionality and provides stability and mobility for the amputee. Volume fluctuation can lead to compromised fit and function. Current socket technology does not accommodate for volume fluctuation. An adjustable interface may improve function and comfort by filling this technology gap. The purpose of this study was to compare the effectiveness of the standard of care (SOC) ischial ramus containment to an adjustable transfemoral prosthetic interface sock...

  11. Radio interferometry and satellite tracking

    CERN Document Server

    Kawase, Seiichiro

    2012-01-01

    Worldwide growth of space communications has caused a rapid increase in the number of satellites operating in geostationary orbits, causing overcrowded orbits. This practical resource is designed to help professionals overcome this problem. This timely book provides a solid understanding of the use of radio interferometers for tracking and monitoring satellites in overcrowded environments. Practitioners learn the fundamentals of radio interferometer hardware, including antennas, receiving equipment, signal processing and phase detection, and measurement accuracies. This in-depth volume describ

  12. Long-term decontamination engineering study. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Geuther, W.J.

    1995-04-03

    This report was prepared by Westinghouse Hanford Company (WHC) with technical and cost estimating support from Pacific Northwest Laboratories (PNL) and Parsons Environmental Services, Inc. (Parsons). This engineering study evaluates the requirements and alternatives for decontamination/treatment of contaminated equipment at the Hanford Site. The purpose of this study is to determine the decontamination/treatment strategy that best supports the Hanford Site environmental restoration mission. It describes the potential waste streams requiring treatment or decontamination, develops the alternatives under consideration establishes the criteria for comparison, evaluates the alternatives, and draws conclusions (i.e., the optimum strategy for decontamination). Although two primary alternatives are discussed, this study does identify other alternatives that may warrant additional study. hanford Site solid waste management program activities include storage, special processing, decontamination/treatment, and disposal facilities. This study focuses on the decontamination/treatment processes (e.g., waste decontamination, size reduction, immobilization, and packaging) that support the environmental restoration mission at the Hanford Site.

  13. Effect of Thyroid Remnant Volume on the Risk of Hypothyroidism After Hemithyroidectomy: A Prospective Study.

    Science.gov (United States)

    Lang, Brian Hung-Hin; Wong, Carlos K H; Wong, Kai Pun; Chu, Kelvin Ka-Wan; Shek, Tony W H

    2017-06-01

    Hypothyroidism is a common sequel after a hemithyroidectomy. Although various risk factors leading to hypothyroidism have been reported, the effect of the contralateral lobe's volume has been understudied. This study aimed to examine the association between the preoperative contralateral lobe's volume and the risk of postoperative hypothyroidism. During a 2-year period, 150 eligible patients undergoing a hemithyroidectomy were evaluated. The volume of the contralateral nonexcised lobe was estimated preoperatively by independent assessors on ultrasonography using the following formula: width (in cm) × depth (in cm) × length (in cm) × (π/6), adjusted for the body surface area (BSA). Postoperative hypothyroidism was defined as serum thyroid-stimulating hormone (TSH) exceeding 4.78 mIU/L. Any significant characteristics in the univariate analysis were entered into the multivariate analysis to determine independent factors. After a mean follow-up period of 53.5 ± 9.4 months, 44 patients (29.3 %) experienced postoperative hypothyroidism, and 10 of these patients required thyroxine replacement. Hypothyroidism was associated with a higher preoperative TSH level (p < 0.001), a smaller BSA-adjusted volume (p < 0.001), fewer ipsilateral nodules (p = 0.037), and the presence of thyroiditis (p = 0.050). After adjustment for thyroiditis, preoperative TSH (p < 0.001), number of ipsilateral nodules (p = 0.048), and BSA-adjusted volume (p < 0.001) were independent factors for hypothyroidism. Patients with a BSA-adjusted volume smaller than 3.2 ml had a threefold greater hypothyroidism risk than those with a BSA-adjusted volume of 3.2 ml or more (p < 0.001). A significant inverse association between the preoperative contralateral lobe's volume and hypothyroidism risk was observed after hemithyroidectomy. Together with a higher preoperative TSH level and fewer ipsilateral nodules, a smaller BSA-adjusted volume measured by preoperative ultrasonography independently predicted

  14. Strategic Studies Quarterly. Volume 4, Number 3, Fall 2010

    Science.gov (United States)

    2010-01-01

    overestimating successes, of which there were many during 2007 and 2008. Bogota has more to do, and Colombia’s president will soon complete his second and final...Hudson or Potomac rivers but rather in Europe at the George C. Marshall European Center for Security Studies in Garmisch, Germany. Unsurprisingly

  15. Buffalo Harbor Study. Preliminary Feasibility Report. Volume I. Main Report.

    Science.gov (United States)

    1983-04-01

    the Buffalo Ornithological Society . Although these groups are not planning agencies, they represent an important trend in land use planning. The groups...Buffalo Historical Society , 1902. Wilson , Carroll L. Coal: Bridge to the Future, Report of the World Coal Study. Cambridge: Ballinger Publishing Company... Wilson , 1980) PLANNING CONSTRAINTS Federal policy on multiobjective planning, derived from both legislative and executive authorities, establishes and

  16. Thermal loading study for FY 1996. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-11-08

    The primary objective of this study was to provide recommendations for Mined Geologic Disposal System requirements affected by thermal loading that will provide sufficient definition to facilitate development of design concepts and support life cycle cost determinations. The study reevaluated and/or redefined selected thermal goals used for design and are currently contained in the requirements documents or the Controlled Design Assumption Document. The study provided recommendations as to what, if any, actions (such as edge loading and limiting of the heat variability between waste packages) are needed and must be accommodated in the design. Additionally, the study provided recommendations as to what alternative thermal loads should be maintained for continued flexibility. This report contains seven appendices: Technical basis for evaluation of thermal goals below the potential nuclear was repository at Yucca Mountain; Thermal-mechanical evaluation of the 200 C drift-wall temperature goal; Evaluation of ground stability and support; Coupled ventilation and hydrothermal evaluations; Heat flow and temperature calculations for continuously ventilated emplacement drifts; Thermal management using aging and/or waste package selection; and Waste stream evaluations.

  17. Snohomish Estuary Wetlands Study. Volume IV. Delineation of Wetland Boundaries

    Science.gov (United States)

    1978-08-01

    River FIG. 4 -G. 5 CARNATION [] Scale in Miles 0 5 1 FALL CITY SNOHOMISH ESTUARY WETLANDS STUDY 8AOUAH FIG. 6-/ 44 Isan A EVRT 12 1 land NO4Carnation on the Snoqualmie River (Tolt River confluence). I B. OBJECTIVES 8. The objectives of the overall Snohomish Estuary Wetlands

  18. The Psychoanalytic Study of the Child. Volume XXIII.

    Science.gov (United States)

    Eissler, Ruth S., Ed.; And Others

    Twenty-seven papers treat aspects of the psychoanalytic study of the child. Problems of psychopathology and therapy considered are the fantasy of the phallic woman, the use of child analysis, the background of perversions, variables in the production of neurotic disturbances, treatment of narcissistic personality disorders, and problems of the…

  19. Depressive symptoms and brain volumes in older adults: a longitudinal magnetic resonance imaging study

    Science.gov (United States)

    Dotson, Vonetta M.; Davatzikos, Christos; Kraut, Michael A.; Resnick, Susan M.

    2009-01-01

    Background Late-life depression is associated with decreased brain volumes, particularly in frontal and temporal areas. Evidence suggests that depressive symptoms at a subclinical level are also associated with brain atrophy in these regions, but most of these associations are based on cross-sectional data. Our objective was to investigate both cross-sectional and longitudinal relations between sub-threshold depressive symptoms and brain volumes in older adults and to examine whether these associations are modified by age. Methods In total, 110 dementia-free adults from the neuroimaging substudy of the Baltimore Longitudinal Study of Aging aged 56 years and older at baseline participated in this study. Participants received annual evaluations for up to 9 years, during which structural magnetic resonance imaging (MRI) scans were acquired and depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Results Mean depressive symptom scores over time were associated with grey matter volume reductions in the left temporal lobe. Depressive symptoms were associated with brain volume reductions with advancing age in the cingulate gyrus and orbitofrontal cortex. Moreover, individuals with higher mean depressive symptom scores showed a faster rate of volume decline in left frontal white matter. Depressive symptoms were not associated with hippocampus volumes. Limitations Limitations include the relative homogeneity of our primarily white and highly educated sample, the lack of information about age at onset of depressive symptoms and potential limitations of the automated brain volume registration. Conclusion Our results suggest that depressive symptoms, even at a subthreshold level, are associated with volume reductions in specific frontal and temporal brain regions, particularly with advancing age. PMID:19721847

  20. Anthropometry: Basic Studies and Applications. Volume 2, 1976 - July 1978

    Science.gov (United States)

    1978-08-01

    in a questionnaire and somatotype measurement study during the 1972 U.S. Masters long-course national champions. Nearly 70 percent of all mala...swimming experience. Somatotype data gathered on the men did not differentiate swimmers in their 70’s from swimmers in their 5C’s, nor did somatotype ...Anthropometry, Males, Physical fitness, Aging (PhysiolDgy) , Body weight Identifiers: Competition, Reprints, Questionnaires, Surveys, Somatotyping

  1. Strategic Studies Quarterly. Volume 5, Number 1, Spring 2011

    Science.gov (United States)

    2011-01-01

    Basil S. Norris Jr., USAF, Retired Gary J. Schaub, PhD Strategic Studies Quarterly (SSQ) (ISSN 1936-1815) is published quarterly by Air University...Terrorism, eds. John N. Moore and Robert F. Turner (Durham, NC: Carolina Academic Press, 2010), 550. 7. This article considers LOAC to encompass jus ad...Critical Infrastructure,” in National Security Law, 2d ed., eds. John N. Moore and Robert F. Turner (Durham, NC: Carolina Academic Press, 2005

  2. Strategic Studies Quarterly. Volume 6, Number 4, Winter 2012

    Science.gov (United States)

    2012-01-01

    PhD Nori Katagiri, PhD George J. Michael, PhD Col Basil S. Norrisjr., USAF, Retired Strategic Studies Quarterly (SSQ) (ISSN 1936-1815) is...empowerment of the regime and partially legiti- mizing its possession of nuclear weapons. Unfortunately, even Malcolm Moore , former "head of the United... Moore , "North Korea now ’fully fledged nuclear power,’" Telegraph (UK), 24 April 2009, http://www.telegraph.co.uk/news/worldnews/asia/northkorea/5212630

  3. Strategic Studies Quarterly. Volume 10, Number 2, Summer 2016

    Science.gov (United States)

    2016-01-01

    pdf . 16. The first offset refers to the threat of massive, offensive striking power from nuclear weapons to deter the numerically superior, in military...www.nipp.org/wp-content/uploads/2016/03/IS-404. pdf ). Why US Nuclear Force Numbers Matter Strategic Studies Quarterly ♦ Summer 2016 15 and rail...Agreement, China also helped Pakistan establish two nuclear power reactors . When China signed the NPT in 1992, these types of actions were ostensibly

  4. Strategic Studies Quarterly. Volume 8, Number 3, Fall 2014

    Science.gov (United States)

    2014-01-01

    Greenspan Commission and the Social Security Reforms of 1983,” in Triumphs and Tragedies of the Modern Presidency: Seventy-Six Case Studies in Presi...amendments to the bill that would direct money to their districts. Ac - cording to lawmakers, these were not earmarks because recipients would have to...of more than 5,300 tanks, but also the Marine Corps’ more than 400 M1s, in his recommendation to Congress to halt production of the tank. Ac

  5. Nuclear electric propulsion mission engineering study. Volume 2: Final report

    Science.gov (United States)

    1973-01-01

    Results of a mission engineering analysis of nuclear-thermionic electric propulsion spacecraft for unmanned interplanetary and geocentric missions are summarized. Critical technologies associated with the development of nuclear electric propulsion (NEP) are assessed, along with the impact of its availability on future space programs. Outer planet and comet rendezvous mission analysis, NEP stage design for geocentric and interplanetary missions, NEP system development cost and unit costs, and technology requirements for NEP stage development are studied.

  6. Transparent Gap Filler Solution over a DVB-RCS2 Satellite Platform in a Railway Scenario: Performance Evaluation Study

    Directory of Open Access Journals (Sweden)

    Peppino Fazio

    2015-01-01

    Full Text Available In this work, a performance study of a system equipped with a transparent Gap Filler solution in a DVB-RCS2 satellite platform has been provided. In particular, a simulation model based on a 3-state Markov chain, overcoming the blockage status through the introduction of a transparent Gap Filler (using devices on both tunnel sides has been implemented. The handover time, due to switching mechanism between satellite and Gap Filler, has been taken into account. As reference scenario, the railway market has been considered, which is characterized by a N-LOS condition, due to service disruptions caused by tunnels, vegetation and buildings. The system performance, in terms of end-to-end delay, queue size and packet loss percentage, have been evaluated, in order to prove the goodness of communications in a real railroad path.

  7. Satellite Communications

    CERN Document Server

    Pelton, Joseph N

    2012-01-01

    The field of satellite communications represents the world's largest space industry. Those who are interested in space need to understand the fundamentals of satellite communications, its technology, operation, business, economic, and regulatory aspects. This book explains all this along with key insights into the field's future growth trends and current strategic challenges. Fundamentals of Satellite Communications is a concise book that gives all of the key facts and figures as well as a strategic view of where this dynamic industry is going. Author Joseph N. Pelton, PhD, former Dean of the International Space University and former Director of Strategic Policy at Intelstat, presents a r

  8. Free volumes and gas transport in polymers: amine-modified epoxy resins as a case study.

    Science.gov (United States)

    Patil, Pushkar N; Roilo, David; Brusa, Roberto S; Miotello, Antonio; Aghion, Stefano; Ferragut, Rafael; Checchetto, Riccardo

    2016-02-07

    The CO2 transport process was studied in a series of amine-modified epoxy resins having different cross-linking densities but the same chemical environment for the penetrant molecules. Positron Annihilation Lifetime Spectroscopy (PALS) was used to monitor the free volume structure of the samples and experimentally evaluate their fractional free volume fh(T) and its temperature evolution. The analysis of the free volume hole size distribution showed that all the holes have a size large enough to accommodate the penetrant molecules at temperatures T above the glass transition temperature Tg. The measured gas diffusion constants at T > Tg have been reproduced in the framework of the free volume theory of diffusion using a novel procedure based on the use of fh(T) as an input experimental parameter.

  9. Flood hazard and flood risk assessment using a time series of satellite images: a case study in Namibia.

    Science.gov (United States)

    Skakun, Sergii; Kussul, Nataliia; Shelestov, Andrii; Kussul, Olga

    2014-08-01

    In this article, the use of time series of satellite imagery to flood hazard mapping and flood risk assessment is presented. Flooded areas are extracted from satellite images for the flood-prone territory, and a maximum flood extent image for each flood event is produced. These maps are further fused to determine relative frequency of inundation (RFI). The study shows that RFI values and relative water depth exhibit the same probabilistic distribution, which is confirmed by Kolmogorov-Smirnov test. The produced RFI map can be used as a flood hazard map, especially in cases when flood modeling is complicated by lack of available data and high uncertainties. The derived RFI map is further used for flood risk assessment. Efficiency of the presented approach is demonstrated for the Katima Mulilo region (Namibia). A time series of Landsat-5/7 satellite images acquired from 1989 to 2012 is processed to derive RFI map using the presented approach. The following direct damage categories are considered in the study for flood risk assessment: dwelling units, roads, health facilities, and schools. The produced flood risk map shows that the risk is distributed uniformly all over the region. The cities and villages with the highest risk are identified. The proposed approach has minimum data requirements, and RFI maps can be generated rapidly to assist rescuers and decisionmakers in case of emergencies. On the other hand, limitations include: strong dependence on the available data sets, and limitations in simulations with extrapolated water depth values.

  10. Estimating daily surface NO2 concentrations from satellite data - a case study over Hong Kong using land use regression models

    Science.gov (United States)

    Anand, Jasdeep S.; Monks, Paul S.

    2017-07-01

    Land use regression (LUR) models have been used in epidemiology to determine the fine-scale spatial variation in air pollutants such as nitrogen dioxide (NO2) in cities and larger regions. However, they are often limited in their temporal resolution, which may potentially be rectified by employing the synoptic coverage provided by satellite measurements. In this work a mixed-effects LUR model is developed to model daily surface NO2 concentrations over the Hong Kong SAR during the period 2005-2015. In situ measurements from the Hong Kong Air Quality Monitoring Network, along with tropospheric vertical column density (VCD) data from the OMI, GOME-2A, and SCIAMACHY satellite instruments were combined with fine-scale land use parameters to provide the spatiotemporal information necessary to predict daily surface concentrations. Cross-validation with the in situ data shows that the mixed-effects LUR model using OMI data has a high predictive power (adj. R2 = 0. 84), especially when compared with surface concentrations derived using the MACC-II reanalysis model dataset (adj. R2 = 0. 11). Time series analysis shows no statistically significant trend in NO2 concentrations during 2005-2015, despite a reported decline in NOx emissions. This study demonstrates the utility in combining satellite data with LUR models to derive daily maps of ambient surface NO2 for use in exposure studies.

  11. Satellite remote sensing of Asian aerosols: a case study of clean, polluted, and Asian dust storm days

    Directory of Open Access Journals (Sweden)

    K. H. Lee

    2010-12-01

    Full Text Available In East Asia, satellite observation is important because aerosols from natural and anthropogenic sources have been recognized as a major source of regional and global air pollution. However, retrieving aerosols properties from satellite observations over land can be difficult because of the surface reflection, complex aerosol composition, and aerosol absorption. In this study, a new aerosol retrieval method called as the Moderate Resolution Imaging Spectroradiometer (MODIS satellite aerosol retrieval (MSTAR was developed and applied to three different aerosol event cases over East Asia. MSTAR uses a separation technique that can distinguish aerosol reflectance from top-of-atmosphere (TOA reflectance. The aerosol optical thickness (AOT was determined by comparing this aerosol reflectance with pre-calculated values. Three case studies show how the methodology identifies discrepancies between measured and calculated values to retrieve more accurate AOT. The comparison between MODIS and the Aerosol Robotic Network (AERONET showed improvement using the suggested methodology with the cluster-based look-up-tables (LUTs (linear slope = 0.94, R = 0.92 than using operational MODIS collection 5 aerosol products (linear slope = 0.78, R = 0.87. In conclusion, the suggested methodology is shown to work well with aerosol models acquired by statistical clustering of the observation data in East Asia.

  12. LNG cascading damage study. Volume I, fracture testing report.

    Energy Technology Data Exchange (ETDEWEB)

    Petti, Jason P.; Kalan, Robert J.

    2011-12-01

    As part of the liquefied natural gas (LNG) Cascading Damage Study, a series of structural tests were conducted to investigate the thermal induced fracture of steel plate structures. The thermal stresses were achieved by applying liquid nitrogen (LN{sub 2}) onto sections of each steel plate. In addition to inducing large thermal stresses, the lowering of the steel temperature simultaneously reduced the fracture toughness. Liquid nitrogen was used as a surrogate for LNG due to safety concerns and since the temperature of LN{sub 2} is similar (-190 C) to LNG (-161 C). The use of LN{sub 2} ensured that the tests could achieve cryogenic temperatures in the range an actual vessel would encounter during a LNG spill. There were four phases to this test series. Phase I was the initial exploratory stage, which was used to develop the testing process. In the Phase II series of tests, larger plates were used and tested until fracture. The plate sizes ranged from 4 ft square pieces to 6 ft square sections with thicknesses from 1/4 inches to 3/4 inches. This phase investigated the cooling rates on larger plates and the effect of different notch geometries (stress concentrations used to initiate brittle fracture). Phase II was divided into two sections, Phase II-A and Phase II-B. Phase II-A used standard A36 steel, while Phase II-B used marine grade steels. In Phase III, the test structures were significantly larger, in the range of 12 ft by 12 ft by 3 ft high. These structures were designed with more complex geometries to include features similar to those on LNG vessels. The final test phase, Phase IV, investigated differences in the heat transfer (cooling rates) between LNG and LN{sub 2}. All of the tests conducted in this study are used in subsequent parts of the LNG Cascading Damage Study, specifically the computational analyses.

  13. Advanced Weapon System (AWS) Sensor Prediction Techniques Study. Volume I

    Science.gov (United States)

    1981-09-01

    Week& • ,I I vetrn•rept Rho ar) Same W SUPPLEMENTARY NOTES RADC Project Engineer: Robert H. LaSalle (URRP) It. KEY WORDS (C..w on roveree eoi nolese Nem...languages and structured according to good software engineering principles . One of the most significant conclusions of this study is that the direct...depends only on (x-y), i.e., C(xy) = C(x-y), p(x,y):= p(x-y), and V(x,y) - V(x-y). In terms of Euclidean motions, stationarity implies invariance under

  14. Strategic Studies Quarterly. Volume 2, Number 3, Fall 2008

    Science.gov (United States)

    2008-01-01

    with the People’s Liberation Army (PLA). The lowest common denominator of these disparate views is very low indeed—a [ 20 ] Strategic Studies Quarterly...Air Force are than those of the People’s Liberation Army , and despite the disagreeable experiences of the Korean War, I have little doubt that we...Quarterly 13 (Au­ tumn 1996): 10–14. 4. Ibid., 15. 5. Richard Meinhart , Strategic Planning by the Chairmen, Joint Chiefs of Staff, 1990–2005 (Carlisle

  15. Strategic Studies Quarterly. Volume 2, Number 2, Summer 2008

    Science.gov (United States)

    2008-06-01

    counterinsurgency, which required large numbers of "boots on the ground" for years, even dec- ades. The Army leadership remained wedded to the Weinberger...its multiple approaches to conflict resolution. Simply put, he studied the "home cultures" of the ethnically diverse Hawaiian population to examine the... wedded to a paradigm of wars fought face-to-face, or head-on. S - S ) Q. ’AI T * SuMM[F 2008 [ 147 ] Book Reviews As a result, Americans see

  16. Nuclear electric propulsion mission engineering study. Volume 1: Executive summary

    Science.gov (United States)

    1973-01-01

    Results of a mission engineering analysis of nuclear-thermionic electric propulsion spacecraft for unmanned interplanetary and geocentric missions are summarized. Critical technologies associated with the development of nuclear electric propulsion (NEP) are assessed. Outer planet and comet rendezvous mission analysis, NEP stage design for geocentric and interplanetary missions, NEP system development cost and unit costs, and technology requirements for NEP stage development are studied. The NEP stage design provides both inherent reliability and high payload mass capability. The NEP stage and payload integration was found to be compatible with the space shuttle.

  17. Impacts of Outer Continental Shelf (OCS) development on recreation and tourism. Volume 2. Final report and case studies

    Energy Technology Data Exchange (ETDEWEB)

    1987-04-01

    The final report for the project is comprised of five volumes. The volume presents the study conclusions, summarizes the methodology used (more detail is found in Volume 3), discusses four case study applications of the model, and contains profiles of coastal communities in an Appendix.

  18. Study of landwater variation over Chao Phraya river basin using GRACE, satellite altimetry and in situ data

    Science.gov (United States)

    Yamamoto, K.; Fukuda, Y.; Nakaegawa, T.; Taniguchi, M.

    2009-12-01

    A project to assess the effects of human activities on the subsurface environment in Asian developing cities has been in progress (Research Institute for Humanity and Nature, Japan, 2009). Bangkok, Thailand is one of the study cities in this project. Using GRACE satellite gravity data, we previously recovered landwater mass variation over the Chao Phraya river basin, where Bangkok is located on downstream. However, mainly because of insufficient spatial resolution of the GRACE data then released, it was difficult to distinguish mass variation over the Chao Phraya basin with the ones of the neighboring Mekong, Irrawaddy and Salween river basins. Recently, some new versions of GRACE data sets have been available, and thus we estimated again the mass variations over these basins using version 2 of CNS/GRGS data set. The result shows that mass variations of the each basin could be distinguished due to improvement of the spatial resolution of the data. One of the interesting things is that a negative interannual mass trend is observed only over the Chao Phraya river basin, while the other basins show positive trend values. One of our concerns was which of the landwater components were decreasing. Because GRACE can only detect total terrestrial water storage, we further used satellite altimeter data to separate surface- and groundwater components. EnviSat data were mainly used as satellite altimetry data in this study, because the mission period is overlapping with GRACE mission and the ground track separation is relatively small. River water levels were recovered from satellite altimetry data, and converted to river water storage. Estimated river water storage was subtracted from the GRACE data. Thus, interannual surface- and groundwater trends were discussed separately. Another concern is whether the landwater decrease is caused by meteorological factors or factors of human activities. Thus, we also compared above results with global hydrological simulation model and

  19. Experimental Study on Volume for Fly Ash of Building Block

    Directory of Open Access Journals (Sweden)

    Ling Wang

    2013-04-01

    Full Text Available Fly ash is a waste substance from thermal power plants, steel mills, etc. That is found in abundance in the world. It has polluted the environment, wasting the cultivated land. This study introduces an experimental research on fly ash being reused effectively, the study introduces raw materials of fly ash brick, production process and product inspection, fly ash content could be amounted to 40%~75%. High doping fly ash bricks are manufactured, which selects wet fly ash from the power plants, adding aggregate with reasonable ratio and additives with reasonable dosage and do the experimental research on manufacture products for properties, production technology and selection about technology parameter of production equipment. Index of strength grade and freezing-thawing resisting etc and the high doping fly ash brick building which we are working on can achieve the national standard on building materials industry. Based on the tests, this achievement of research has a very wide practical prospect in using fly ash, industrial waste residue, environmental protection and reducing the cost of enterprises. The efficient reuse of fly ash from coal boiler and power plants has very vital significance of protecting the environment, benefiting descendants and developing of circular economy.

  20. Proceedings of the Seventeenth NASA Propagation Experimenters Meeting (NAPEX 17) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    Science.gov (United States)

    Davarian, Faramaz (Editor)

    1993-01-01

    The NASA Propagation Experimenters Meeting (NAPEX) is convened annually to discuss studies made on radio wave propagation by investors from domestic and international organizations. NAPEX 17 was held on 15 June 1993. The meeting was organized into two technical sessions. The first session was dedicated to slant path propagation studies and experiments. The second session focused on propagation studies for mobile and personal communications. Preceding NAPEX 17, the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop was held on 14 June 1993 to review ACTS propagation activities with emphasis on ACTS experiments status and data collection, processing, and exchange.

  1. Spider phobia is associated with decreased left amygdala volume: a cross-sectional study

    Science.gov (United States)

    2013-01-01

    Background Evidence from animal and human studies imply the amygdala as the most critical structure involved in processing of fear-relevant stimuli. In phobias, the amygdala seems to play a crucial role in the pathogenesis and maintenance of the disorder. However, the neuropathology of specific phobias remains poorly understood. In the present study, we investigated whether patients with spider phobia show altered amygdala volumes as compared to healthy control subjects. Methods Twenty female patients with spider phobia and twenty age-matched healthy female controls underwent magnetic resonance imaging to investigate amygdala volumes. The amygdalae were segmented using an automatic, model-based segmentation tool (FSL FIRST). Differences in amygdala volume were investigated by multivariate analysis of covariance with group as between-subject factor and left and right amygdala as dependent factors. The relation between amygdala volume and clinical features such as symptom severity, disgust sensitivity, trait anxiety and duration of illness was investigated by Spearman correlation analysis. Results Spider phobic patients showed significantly smaller left amygdala volume than healthy controls. No significant difference in right amygdala volume was detected. Furthermore, the diminished amygdala size in patients was related to higher symptom severity, but not to higher disgust sensitivity or trait anxiety and was independent of age. Conclusions In summary, the results reveal a relation between higher symptom severity and smaller left amygdala volume in patients with spider phobia. This relation was independent of other potential confounders such as the disgust sensitivity or trait anxiety. The findings suggest that greater spider phobic fear is associated with smaller left amygdala. However, the smaller left amygdala volume may either stand for a higher vulnerability to develop a phobic disorder or emerge as a consequence of the disorder. PMID:23442196

  2. Orbitofrontal lobe volume deficits in Antipsychotic-Naive schizophrenia: A 3-Tesla MRI study

    Directory of Open Access Journals (Sweden)

    Behere Rishikesh

    2009-01-01

    Full Text Available Background: Prefrontal cortex deficits have been consistently demonstrated in schizophrenia. The orbitofrontal lobe (OFL, a critical component of the prefrontal cortex, subserves social and neuro-cognitive functions. While these functional impairments are established in schizophrenia, the OFL volume deficits have not been well studied, especially in antipsychotic-naοve patients. Aim: To study OFL volume deficits in antipsychotic-naοve schizophrenia patients in comparison with matched healthy controls using high-resolution 3-tesla (3T magnetic resonance imaging (MRI. Materials and Methods: Fourteen antipsychotic-naοve schizophrenia patients (DSM-IV and 14 age-, sex-, handedness- and education-matched healthy controls were scanned using 3T MRI. Psychopathology was assessed in the patient group using the scale for assessment of negative symptoms and the scale for assessment of positive symptoms (SAPS. The OFL volume was measured using Region of Interest (ROI-based manual morphometry technique, with good inter-rater reliability (intra-class correlation coefficient = 0.98. Results: Total OFL volume was significantly smaller in schizophrenia patients (43.3 ± 9.6 mL in comparison with healthy controls (52.1 ± 12.2 mL after controlling for the potential confounding effects of age, sex and intracranial volume (F = 5.3, P = .03. Duration of untreated psychosis did not correlate significantly with OFL volumes. There was a trend towards significant negative correlation between the left and total OFL volumes and SAPS scores (r = -0.49, P = .06. Conclusion: OFL volume deficits might underlie the pathogenesis of schizophrenia symptoms with possible neuro-developmental origins.

  3. Effect of malaria on placental volume measured using three-dimensional ultrasound: a pilot study

    Directory of Open Access Journals (Sweden)

    Rijken Marcus J

    2012-01-01

    Full Text Available Abstract Background The presence of malaria parasites and histopathological changes in the placenta are associated with a reduction in birth weight, principally due to intrauterine growth restriction. The aim of this study was to examine the feasibility of studying early pregnancy placental volumes using three-dimensional (3D ultrasound in a malaria endemic area, as a small volume in the second trimester may be an indicator of intra-uterine growth restriction and placental insufficiency. Methods Placenta volumes were acquired using a portable ultrasound machine and a 3D ultrasound transducer and estimated using the Virtual Organ Computer-aided AnaLysis (VOCAL image analysis software package. Intra-observer reliability and limits of agreement of the placenta volume measurements were calculated. Polynomial regression models for the mean and standard deviation as a function of gestational age for the placental volumes of uninfected women were created and tested. Based on these equations each measurement was converted into a z -score. The z-scores of the placental volumes of malaria infected and uninfected women were then compared. Results Eighty-four women (uninfected = 65; infected = 19 with a posterior placenta delivered congenitally normal, live born, single babies. The mean placental volumes in the uninfected women were modeled to fit 5th, 10th, 50th, 90th and 95th centiles for 14-24 weeks' gestation. Most placenta volumes in the infected women were below the 50th centile for gestational age; most of those with Plasmodium falciparum were below the 10th centile. The 95% intra-observer limits of agreement for first and second measurements were ± 37.0 mL and ± 25.4 mL at 30 degrees and 15 degrees rotation respectively. Conclusion The new technique of 3D ultrasound volumetry of the placenta may be useful to improve our understanding of the pathophysiological constraints on foetal growth caused by malaria infection in early pregnancy.

  4. A Cusp Density Enhancement Study using e-POP Satellite Data

    Science.gov (United States)

    Sadler, B.

    2015-12-01

    CHAMP satellite observations have confirmed neutral density enhancements which are localized to the high latitude polar cusp region. These small-scale density structures are consistently correlated with strong fine-scale field-aligned currents. A possible driver of these density enhancements is soft electron precipitation which, through processes associated with ion-outflow, results in a density enhancement in the cusp vicinity at the altitudes observed by CHAMP. We investigate this mechanism with recent observations from the CASSIOPE / e-POP satellite and numerical simulations. In-situ data for selected cusp transit events are presented. Numerical simulation predictions are discussed comparing two electron-precipitation models: a fine-scale ion-outflow model and a global-scale Joule heating / increased conductivity model (CMIT).

  5. Satellite Altimetry and GRACE Gravimetry for Studies of Annual Water Storage Variations in Bangladesh

    Directory of Open Access Journals (Sweden)

    Ole Andersen

    2008-01-01

    Full Text Available Four different data sources have been compared with respect to observations of the annual water storage variations in the region of Bangladesh. Data from satellite altimeters and river gauges estimates the variation in surface water storage in the major rivers of Bangladesh. The GRACE satellites measure the integrated mass change and hence the terrestrial soil moisture variations, which can also be estimated by a hydrological model (GLDAS. These types of observations enable the derivation of the integrated water storage in the entire region of Bangladesh. For all data types, the annual signal has been estimated from a common dataset spanning the period 2003 and 2004. All four different data observe that water storage in Bangladesh is largely dominated by an annual signal with a phase peaking in early September. The annual variations in river level peaks roughly two weeks earlier than terrestrial soil moisture observations by GRACE observations and GLDAS model output.

  6. Feasibility study of a solar power satellite system configured by formation flying

    Energy Technology Data Exchange (ETDEWEB)

    Takeichi, Noboru; Ueno, Hiroshi; Oda, Mitsushige [Japan Aerospace Exploration Agency (JAXA), Inst. of Space Technology and Aeronautics, Tsukuba, Ibaraki (Japan)

    2005-11-15

    This paper presents a new concept of a solar power satellite system configured by formation flying. In this concept, the solar power satellite system consists of sunlight reflectors and an energy generator-transmitter. The energy generator- transmitter is on a common GEO, and the reflectors are placed on the north and south by using solar pressure to raise their orbits from GEO. Therefore, the orbits of the reflectors and that of the energy generator-transmitter make three parallel GEOs. The feasibility of the concept and its requirements are also discussed, focusing on the orbital and attitude mechanics of the reflector. Because the tilt angle of the sunlight changes with the turning of the seasons, it is sometimes necessary to raise the orbit by thrusters especially around the solstice. For attitude dynamics, spin stabilization and thruster control are discussed as the attitude control strategies against the gravity gradient torque, which acts as a persistent periodic disturbance. (Author)

  7. A study and experiment plan for digital mobile communication via satellite

    Science.gov (United States)

    Jones, J. J.; Craighill, E. J.; Evans, R. G.; Vincze, A. D.; Tom, N. N.

    1978-01-01

    The viability of mobile communications is examined within the context of a frequency division multiple access, single channel per carrier satellite system emphasizing digital techniques to serve a large population of users. The intent is to provide the mobile users with a grade of service consistant with the requirements for remote, rural (perhaps emergency) voice communications, but which approaches toll quality speech. A traffic model is derived on which to base the determination of the required maximum number of satellite channels to provide the anticipated level of service. Various voice digitalization and digital modulation schemes are reviewed along with a general link analysis of the mobile system. Demand assignment multiple access considerations and analysis tradeoffs are presented. Finally, a completed configuration is described.

  8. Satellite altimetry and GRACE gravimetry for studies of annual water storage variations in Bangladesh

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Berry, P.; Freeman, J.;

    2008-01-01

    Four different data sources have been compared with respect to observations of the annual water storage variations in the region of Bangladesh. Data from satellite altimeters and river gauges estimates the variation in surface water storage in the major rivers of Bangladesh. The GRACE satellites...... measure the integrated mass change and hence the terrestrial soil moisture variations, which can also be estimated by a hydrological model (GLDAS). These types of observations enable the derivation of the integrated water storage in the entire region of Bangladesh. For all data types, the annual signal...... has been estimated from a common dataset spanning the period 2003 and 2004. All four different data observe that water storage in Bangladesh is largely dominated by an annual signal with a phase peaking in early September. The annual variations in river level peaks roughly two weeks earlier than...

  9. A study of the validation of atmospheric CO2 from satellite hyper spectral remote sensing

    Directory of Open Access Journals (Sweden)

    Miao Zhang

    2014-09-01

    Full Text Available Three total column dry-air mole fractions of CO2 (XCO2 products from satellite retrievals, namely SCIAMACHY, NIES-GOSAT, and ACOS-GOSAT, in the Northern Hemisphere were validated by ground data from the Total Carbon Column Observing Network (TCCON. The results showed that the satellite data have the same seasonal fluctuations as in the TCCON data, with maximum in April or May and minimum in August or September. The three products all underestimate the XCO2. The ACOS-GOSAT and the NIES-GOSAT products are roughly equivalent, and their mean standard deviations are 2.26 × 10−6 and 2.27 × 10−6 respectively. The accuracy of the SCIMACHY product is slightly lower, with a mean standard deviation of 2.91 × 10−6.

  10. The use of satellite laser observations in studying the crustal movements

    Directory of Open Access Journals (Sweden)

    Gamal F. Attia

    2012-12-01

    Full Text Available The mutual tectonic displacements of the lithospheric blocks take place within the deep fracture dividing them into hundreds and thousands kilometers long. It is possible to suggest that the reason of the accumulation of considerable local shift deformations is the change of the velocity of the tectonic motion in some or other parts of fractures as a result of different physical, chemical and mechanical processes. Nowadays, the range precision of Satellite Laser Ranging (SLR technique reaches a few millimeters level. Therefore, the space geodesy technique becomes a very important tool in detecting and monitoring recent crustal movements. Regular repeated measurements of the baselines between some stations on different plates give the possibility to construct precise and detail models of crustal movements. In this paper, the length of four baselines between Helwan-SLR station and other four SLR stations are calculated using satellite geodetical technique.

  11. A comparative study of Saturn's icy satellites spectrophotometric properties by Cassini/VIMS

    Science.gov (United States)

    Filacchione, G.; Capaccioni, F.; Coradini, A.; Cerroni, P.; Tosi, F.; McCord, T. B.; Baines, K. H.; Bellucci, G.; Brown, R. H.; Bibring, J. P.; Vims Team

    The main spectral properties of Saturn s icy satellites are investigated through the hyperspectral data collected by VIMS Visual and Infrared Mapping Spectrometer in the VIS-NIR range 0 35-5 1 micron from July 2004 to nowadays In this work we make a comparative analysis of more than 500 full-disk spectra obtained at different phase angles and leading-trailing coverage for 14 satellites Mimas Enceladus Tethys Dione Rhea Hyperion Iapetus Janus Epimetheus Telesto Calypso Atlas Prometheus Pandora The amount of contaminants organics and tholins on the surfaces is estimated thanks to the visible spectral slopes abundance of water ice and particle sizes are retrieved through the 1 5 2 0 and 3 0 micron absorption band strengths We present here also preliminary phase curves and mean full-disk spectra This work is supported by an ASI Italian Space Agency grant

  12. Blanket comparison and selection study. Final report. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1984-09-01

    The study focused on: (1) Development of reference design guidelines, evaluation criteria, and a methodology for evaluating and ranking candidate blanket concepts. (2) Compilation of the required data base and development of a uniform systems analysis for comparison. (3) Development of conceptual designs for the comparative evaluation. (4) Evaluation of leading concepts for engineering feasibility, economic performance, and safety. (5) Identification and prioritization of R and D requirements for the leading blanket concepts. Sixteen concepts (nine TMR and seven tokamak) which were identified as leading candidates in the early phases of the study, were evaluated in detail. The overall evaluation concluded that the following concepts should provide the focus for the blanket R and D program: (Breeder/Coolant/Structure), Lithium/Lithium/Vanadium Alloy, Li/sub 2/O/Helium/Ferritic Steel, LiPb Alloy/LiPb Alloy/Vanadium Alloy, and Lithium/Helium/Ferritic Steel. The primary R and D issues for the Li/Li/V concept are the development of an advanced structural alloy, resolution of MHD and corrosion problems, provision for an inert atmosphere (e.g., N/sub 2/) in the reactor building, and the development of non-water cooled near-plasma components, particularly for the tokamak. The main issues for the LiPb/LiPb/V concept are similar to the Li/Li/V blanket with the addition of resolving the tritium recovery issue. The R and D issues for Li/sub 2/O/He/FS concept include resolution of the tritium recovery/containment issue, achieving adequate tritium breeding and resolving other solid breeder issues such as swelling and fabrication concerns. Major concerns for the Li/He/FS concept are related to its rather poor economic performance. Improvement of its economic performance will be somewhat concept-dependent and will be more of a systems engineering issue.

  13. Blanket comparison and selection study. Final report. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    1984-09-01

    The study focused on: (1) Development of reference design guidelines, evaluation criteria, and a methodology for evaluating and ranking candidate blanket concepts. (2) Compilation of the required data base and development of a uniform systems analysis for comparison. (3) Development of conceptual designs for the comparative evaluation. (4) Evaluation of leading concepts for engineering feasibility, economic performance, and safety. (5) Identification and prioritization of R and D requirements for the leading blanket concepts. Sixteen concepts (nine TMR and seven tokamak) which were identified as leading candidates in the early phases of the study, were evaluated in detail. The overall evaluation concluded that the following concepts should provide the focus for the blanket R and D program: (Breeder/Coolant/Structure), Lithium/Lithium/Vanadium Alloy, Li/sub 2/O/Helium/Ferritic Steel, LiPb Alloy/LiPb Alloy/Vanadium Alloy, and Lithium/Helium/Ferritic Steel. The primary R and D issues for the Li/Li/V concept are the development of an advanced structural alloy, resolution of MHD and corrosion problems, provision for an inert atmosphere (e.g., N/sub 2/) in the reactor building, and the development of non-water cooled near-plasma components, particularly for the tokamak. The main issues for the LiPb/LiPb/V concept are similar to the Li/Li/V blanket with the addition of resolving the tritium recovery issue. The R and D issues for Li/sub 2/O/He/FS concept include resolution of the tritium recovery/containment issue, achieving adequate tritium breeding and resolving other solid breeder issues such as swelling and fabrication concerns. Major concerns for the Li/He/FS concepts are related to its rather poor economic performance. Improvement of its economic performance will be somewhat concept-dependent and will be more of a systems engineering issue.

  14. Blanket comparison and selection study. Final report. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1984-09-01

    The study focused on: (1) Development of reference design guidelines, evaluation criteria, and a methodology for evaluating and ranking candidate blanket concepts. (2) Compilation of the required data base and development of a uniform systems analysis for comparison. (3) Development of conceptual designs for the comparative evaluation. (4) Evaluation of leading concepts for engineering feasibility, economic performance, and safety. (5) Identification and prioritization of R and D requirements for the leading blanket concepts. Sixteen concepts (nine TMR and seven tokamak) which were identified as leading candidates in the early phases of the study, were evaluated in detail. The overall evaluation concluded that the following concepts should provide the focus for the blanket R and D program: (Breeder/Coolant/Structure), Lithium/Lithium/Vanadium Alloy, Li/sub 2/O/Helium/Ferritic Steel, LiPb Alloy/LiPb Alloy/Vanadium Alloy, and Lithium/Helium/Ferritic Steel. The primary R and D issues for the Li/Li/V concept are the development of an advanced structural alloy, resolution of MHD and corrosion problems, provision for an inert atmosphere (e.g., N/sub 2/) in the reactor building, and the development of non-water cooled near-plasma components, particularly for the tokamak. The main issues for the LiPb/LiPb/V concepts are similar to the Li/Li/V blanket with the addition of resolving the tritium recovery issue. The R and D issues for Li/sub 2/O/He/FS concept include resolution of the tritium recovery/containment issue, achieving adequate tritium breeding and resolving other solid breeder issues such as swelling and fabrication concerns. Major concerns for the Li/He/FS concept are related to its rather poor economic performance. Improvement of its economic performance will be somewhat concept-dependent and will be more of a systems engineering issue.

  15. Preliminary benefits study for a public service communications satellite system: Task order 2

    Science.gov (United States)

    1978-01-01

    The economic and social benefits to accrue from an operational public service communications satellite system are estimated for the following applications: teleradiology, emergency medical services, teleconferencing for both civilian and defense agencies, data transfer, remote cardiac monitoring, teleconsultation, continuing education for professionals, and severe storm warning. The potential impact of improved communication on the cost and quality of services are assessed for various agencies, professions, and industries.

  16. Study of Ice Crystal Orientation in Cirrus Clouds based on Satellite Polarized Radiance Measurements

    OpenAIRE

    Noel, Vincent; Chepfer, Hélène

    2004-01-01

    International audience; The goal of this paper is to retrieve information about ice particle orientation in cirrus clouds. This is achieved by comparing simulations of sunlight reflection on a cirrus cloud with measurements of polarized radiances from the spaceborne instrument Polarization and Directionality of the Earth's Reflectance (POLDER-1) on Advanced Earth Observing Satellite-1 (ADEOS-1). Results show that horizontal orientation of cr ystals can be spotted by the presence of a local ma...

  17. Comparing regional modeling (CHIMERE) and satellite observations of aerosols (PARASOL): Methodology and case study over Mexico

    Science.gov (United States)

    Stromatas, Stavros

    2010-05-01

    S. Stromatas (1), S. Turquety (1), H. Chepfer (1), L. Menut (1), B. Bessagnet (2), JC Pere (2), D. Tanré (3) . (1) Laboratoire de Météorologie Dynamique, CNRS/IPSL, École Polytechnique, 91128 Palaiseau Cedex, France, (2) INERIS, Institut National de l'Environnement Industriel et des Risques, Parc technologique ALATA, 60550 Verneuil en Halatte, FRANCE, (3) Laboratoire d'Optique Atmosphérique/CNRS Univ. des Sciences et Tech. de Lille, 59650 - Villeneuve d'Ascq, France. Atmospheric suspended particles (aerosols) have significant radiative and environmental impacts, affecting human health, visibility and climate. Therefore, they are regulated by air quality standards worldwide, and monitored by regional observation networks. Satellite observations vastly improve the horizontal and temporal coverage, providing daily distributions. Aerosols are currently estimated using aerosol optical depth (AOD) retrievals, a quantitative measure of the extinction of solar radiation by aerosol scattering and absorption between the point of observation and the top of the atmosphere. Even though remarkable progresses in aerosol modeling by chemistry-transport models (CTM) and measurement experiments have been made in recent years, there is still a significant divergence between the modeled and observed results. However, AOD retrievals from satellites remains a highly challenging task mostly because it depends on a variety of different parameters such as cloud contamination, surface reflectance contributions and a priori assumptions on aerosol types, each one of them incorporating its own difficulties. Therefore, comparisons between CTM and observations are often difficult to interpret. In this presentation, we will discuss comparisons between regional modeling (CHIMERE CTM) over Mexico and satellite observations obtained by the POLDER instrument embarked on PARASOL micro-satellite. After a comparison of the model AOD with the retrieved L2 AOD, we will present an alternative

  18. Study on thermal properties of Cd-Ni batteries for satellites

    Science.gov (United States)

    Jingang, Hu

    1995-06-01

    Empirical research was carried out on thermal properties associated with the use of Cd-Ni storage cells in satellite engineering. Introduction is made of measured cell thermal capacities as well as amounts of heat put out by systems. The systems in question possess the advantages of being simple and reliable. Measured results are given, and, in conjunction with that, comparisons are carried out with data from abroad.

  19. A study of the effect of group delay distortion on an SMSK satellite communications channel

    Science.gov (United States)

    Kerczewski, Robert J.

    1987-01-01

    The effects of group delay distortion on an SMSK satellite communications channel have been investigated. Software and hardware simulations have been used to determine the effects of channel group delay variations with frequency on the bit error rate for a 220 Mbps SMSK channel. These simulations indicate that group delay distortions can significantly degrade the bit error rate performance. The severity of the degradation is dependent on the amount, type, and spectral location of the group delay distortion.

  20. H-- Filtering Algorithms Case Study GPS-Based Satellite Orbit Determination

    Science.gov (United States)

    Kuang, Jinlu; Tan, Soonhie

    In this paper the new Hfiltering algorithms for the design of navigation systems for autonomous LEO satellite is introduced. The nominal orbit (i.e., position and velocity) is computed by integrating the classical orbital differential equations of the LEO satellite by using the 7th-8th order Runge- Kutta algorithms. The perturbations due to the atmospheric drag force, the lunar-solar attraction and the solar radiation pressure are included together with the Earth gravity model (EGM-96). The spherical harmonic coefficients of the EGM-96 are considered up to 72 for the order and degree. By way of the MATLAB GPSoft software, the simulated pseudo ranges between the user LEO satellite and the visible GPS satellites are generated when given the appropriate angle of mask. The effects of the thermal noises, tropospheric refraction, ionospheric refraction, and multipath of the antenna are also compensated numerically in the simulated pseudo ranges. The dynamic Position-Velocity (PV) model is obtained by modeling the velocity as nearly constant being the white noise process. To further accommodate acceleration in the process model, the Position-Velocity-Acceleration (PVA) model is investigated by assuming the acceleration to be the Gaussian- Markov process. The state vector for the PV model becomes 8-dimensional (3-states for positions, 3-states for velocities, 1-state for range (clock) bias error, 1-state for range (clock) drift error). The state vector for the PV model becomes 11-dimensional with the addition of three more acceleration states. Three filtering approaches are used to smooth the orbit solution based upon the GPS pseudo range observables. The numerical simulation shows that the observed orbit root-mean-square errors of 60 meters by using the least squares adjustment method are improved to be less than 5 meters within 16 hours of tracking time by using the Hfiltering algorithms. The results are compared with the ones obtained by using the Extended Kalman

  1. Earth Observatory Satellite system definition study. Report 4: Low cost management approach and recommendations

    Science.gov (United States)

    1974-01-01

    An analysis of low cost management approaches for the development of the Earth Observatory Satellite (EOS) is presented. The factors of the program which tend to increase costs are identified. The NASA/Industry interface is stressed to show how the interface can be improved to produce reduced program costs. Techniques and examples of cost reduction which can be applied to the EOS program are tabulated. Specific recommendations for actions to be taken to reduce costs in prescribed areas are submitted.

  2. Earth Observatory Satellite system definition study. Report no. 4: Management approach recommendations

    Science.gov (United States)

    1974-01-01

    A management approach for the Earth Observatory Satellite (EOS) which will meet the challenge of a constrained cost environment is presented. Areas of consideration are contracting techniques, test philosophy, reliability and quality assurance requirements, commonality options, and documentation and control requirements. The various functional areas which were examined for cost reduction possibilities are identified. The recommended management approach is developed to show the primary and alternative methods.

  3. SARSAT (Search and Rescue Satellite) Operational Data Categorization and Accuracy Studies.

    Science.gov (United States)

    1985-09-01

    poursuite terrestre SARSAT jusqu’aux usagers du systime de recherche et de sauvetage opgrationnels influe de faqon importante sur le succis qu’auront...or an Emergency Position Indicating Radio Beacon (EPIRB), is detected by a polar- orbiting spacecraft equipped with suitable receive.-s. Such signals...positioning performance, satellites in a low-altitude polar orbit are used. The low altitude results in low ELT/EPIRB power requirements, good Doppler-shift

  4. Study and modeling of the most energetic Active Galactic Nuclei with the Fermi satellite; Etude et modelisation des noyaux actifs de galaxie les plus energetiques avec le satellite Fermi

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, D.

    2010-06-15

    The Fermi satellite was launched in June 2008. The onboard LAT detector is dedicated to the study of galactic and extra-galactic gamma sources with an energy comprised between 200 MeV and 300 GeV. 1451 sources have been detected in less than 11 months. This document is divided into 6 chapters: 1) gamma astronomy, 2) the Fermi satellite, 3) the active galactic nuclei (NAG), 4) the observation of several blazars (PKS-2155-304 and PG-1553+113) and its simulation, 5) the observation of PKS-2155-304 with both RXTE and Fermi, and 6) conclusion

  5. A review of satellite radar altimetry applied to coastal ocean studies

    Science.gov (United States)

    Vignudelli, Stefano

    2016-07-01

    Satellite radar altimetry is today considered a mature technique in open ocean. The data stream from the various satellite missions are routinely used for a number of applications. In the last decade, significant research has been carried out into overcoming the problems to extend the capabilities of radar altimeters to the coastal zone, with the aim to integrate the altimeter-derived measurements of sea level, wind speed and significant wave height into coastal ocean observing systems. More/better (and new) datasets are being produced. Moreover, the advent of new satellite missions, both nadir-viewing (e.g., Sentinel-3) and wide-swath (e.g. SWOT), should globally improve both quantity and quality of coastal altimetry data. In this talk, after a brief review of the challenges in coastal altimetry and description of the new products, we showcase some application examples how the new products can be exploited, and we discuss directions for a global coastal altimetry dataset as an asset for long term monitoring of sea level and sea state in the coastal ocean.

  6. Reusable Reentry Satellite (RRS) system design study: System cost estimates document

    Science.gov (United States)

    1991-01-01

    The Reusable Reentry Satellite (RRS) program was initiated to provide life science investigators relatively inexpensive, frequent access to space for extended periods of time with eventual satellite recovery on earth. The RRS will provide an on-orbit laboratory for research on biological and material processes, be launched from a number of expendable launch vehicles, and operate in Low-Altitude Earth Orbit (LEO) as a free-flying unmanned laboratory. SAIC's design will provide independent atmospheric reentry and soft landing in the continental U.S., orbit for a maximum of 60 days, and will sustain three flights per year for 10 years. The Reusable Reentry Vehicle (RRV) will be 3-axis stabilized with artificial gravity up to 1.5g's, be rugged and easily maintainable, and have a modular design to accommodate a satellite bus and separate modular payloads (e.g., rodent module, general biological module, ESA microgravity botany facility, general botany module). The purpose of this System Cost Estimate Document is to provide a Life Cycle Cost Estimate (LCCE) for a NASA RRS Program using SAIC's RRS design. The estimate includes development, procurement, and 10 years of operations and support (O&S) costs for NASA's RRS program. The estimate does not include costs for other agencies which may track or interface with the RRS program (e.g., Air Force tracking agencies or individual RRS experimenters involved with special payload modules (PM's)). The life cycle cost estimate extends over the 10 year operation and support period FY99-2008.

  7. Atmospheric front over the East China Sea studied by multisensor satellite and in situ data

    Science.gov (United States)

    Ivanov, Andrei Y.; Alpers, Werner; Litovchenko, Konstantin T.; He, Ming-Xia; Feng, Qian; Fang, Mingqiang; Yan, Xiao-Hai

    2004-12-01

    A frontal feature visible on a synthetic aperture radar (SAR) image acquired by the Radarsat satellite over the East China Sea on 19 November 2000 is analyzed in conjunction with data acquired by Quikscat, TOPEX/Poseidon, Tropical Rain Measurement Mission (TRMM), Defense Meteorological Satellite Program (DMSP), and National Oceanic and Atmospheric Administration (NOAA) satellites, and with data obtained from ship measurements. Although this frontal feature is located close to the Kuroshio front, it is demonstrated that it is not a sea surface manifestation of an oceanic front, but rather of an atmospheric front extending over 800 km from an area of the Pacific Ocean northeast of Taiwan to the southern coast of Korea. It is a cold front moving in the southeast direction with a speed of approximately 45-50 km/hour and associated with a 40-km-wide rainband trailing the front. The Radarsat image, which has a resolution of 50 m, reveals fine-scale structures of the atmospheric front, in particular small-scale convective rain cells embedded in the front. Conclusion is drawn that accurate interpretation of frontal features in SAR images requires use of additional meteorological and remote sensing data and information.

  8. Experiment module concepts study. Volume 1: Management summary

    Science.gov (United States)

    1970-01-01

    The minimum number of standardized (common) module concepts that will satisfy the experiment program for manned space stations at least cost is investigated. The module interfaces with other elements such as the space shuttle, ground stations, and the experiments themselves are defined. The total experiment module program resource and test requirements are also considered. The minimum number of common module concepts that will satisfy the program at least cost is found to be three, plus a propulsion slice and certain experiment-peculiar integration hardware. The experiment modules rely on the space station for operational, maintenance, and logistic support. They are compatible with both expendable and shuttle launch vehicles, and with servicing by shuttle, tug, or directly from the space station. A total experiment module program cost of approximately $2319M under the study assumptions is indicated. This total is made up of $838M for experiment module development and production, $806M for experiment equipment, and $675M for interface hardware, experiment integration, launch and flight operations, and program management and support.

  9. Satellite Geomagnetism

    DEFF Research Database (Denmark)

    Olsen, Nils; Stolle, Claudia

    2012-01-01

    Observations of Earth’s magnetic field from space began more than 50 years ago. A continuous monitoring of the field using low Earth orbit (LEO) satellites, however, started only in 1999, and three satellites have taken highprecision measurements of the geomagnetic field during the past decade...... ability to characterize and understand the many sources that contribute to Earth’s magnetic field. In this review, we summarize investigations of Earth’s interior and environment that have been possible through the analysis of high-precision magnetic field observations taken by LEO satellites........ The unprecedented time-space coverage of their data opened revolutionary new possibilities for monitoring, understanding, and exploring Earth’s magnetic field. In the near future, the three-satellite constellation Swarm will ensure continuity of such measurement and provide enhanced possibilities to improve our...

  10. A study of nasal cavity volume in patients with cleft lip and palate by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Kenichi [Showa Univ., Tokyo (Japan). School of Medicine

    1996-02-01

    Nasal cavity volume was studied in 11 patients with cleft lip and palate by magnetic resonance imaging. The areas of horizontal sections of the nasal cavity on the cleft and non-cleft sides were measured with the help of a personal computer and image analyzing software. Nasal cavity volume was determined by integrated volume calculation. The volume of each side was measured before and after cleft lip repair. Before cleft lip repair nasal cavity volume on the non-cleft side was larger than on the cleft side. However there was no significant difference in the volume of the cleft and non-cleft sides after cleft lip repair. (author)

  11. A multi-satellite study of accelerated ionospheric ion beams above the polar cap

    Directory of Open Access Journals (Sweden)

    R. Maggiolo

    2006-07-01

    Full Text Available This paper presents a study of nearly field-aligned outflowing ion beams observed on the Cluster satellites over the polar cap. Data are taken at geocentric radial distances of the order of 5–9 RE. The distinction is made between ion beams originating from the polar cusp/cleft and beams accelerated almost along the magnetic field line passing by the spacecraft. Polar cusp beams are characterized by nearly field-aligned proton and oxygen ions with an energy ratio EO+ / EH+, of the order of 3 to 4, due to the ion energy repartition inside the source and to the latitudinal extension of the source. Rapid variations in the outflowing ion energy are linked with pulses/modifications of the convection electric field. Cluster data allow one to show that these perturbations of the convection velocity and the associated ion structures propagate at the convection velocity.

    In contrast, polar cap local ion beams are characterized by field-aligned proton and oxygen ions with similar energies. These beams show the typical inverted V structures usually observed in the auroral zone and are associated with a quasi-static converging electric field indicative of a field-aligned electric field. The field-aligned potential drop fits well the ion energy profile. The simultaneous observation of precipitating electrons and upflowing ions of similar energies at the Cluster orbit indicates that the spacecraft are crossing the mid-altitude part of the acceleration region. In the polar cap, the parallel electric field can thus extend to altitudes higher than 5 Earth radii. A detailed analysis of the distribution functions shows that the ions are heated during their parallel acceleration and that energy is exchanged between H+ and O+. Furthermore, intense electrostatic waves are observed simultaneously. These observations could be due to an ion-ion two-stream instability.

  12. Study of rain attenuation in Ka band for satellite communication in South Korea

    Science.gov (United States)

    Shrestha, Sujan; Choi, Dong-You

    2016-10-01

    The important factor to be considered in the link budget estimation for satellite communication systems, operating at frequencies above 10 GHz is the rain attenuation. Scattering and absorption are the main concern for system designers at these frequency bands. This has resulted in the need for suitable prediction models that can best provide estimates of attenuation due to rain with available information of rain attenuation data. Researchers have developed models that can be used to estimate 1-min rainfall attenuation distribution for earth space link but there is still some confusion with regard to choosing the right model to predict attenuation for the location of interest. In this context, the existing prediction models need to be tested against the measured results. This paper presents studies on rain attenuation at 19.8 GHz, which specifies the performance parameters for Ka-Band under earth space communication system. It presents the experimental result of rain rates and rain-induced attenuation in 19.8 and 20.73 GHz for vertical and circular polarization respectively. The received signal data for rain attenuation and rain rate were collected at 10 s intervals over a three year periods from 2013 to 2015. The data highlights the impact of clear air variation and rain fade loss. Rain rate data was measured through OTT Parsivel. During the observation period, rain rates of about 50 mm/h and attenuation values of 11.6 dB for 0.01% of the time were noted. The experimental link was set up at Korea Radio Promotion Association, Mokdong, Seoul. Out of several models, this paper present discussion and comparison of ITU-R P.618-12, Unified Method, Dissanayake Allnutt and Haidara (DAH), Simple Attenuation (SAM), Crane Global and Ramachandran and Kumar models. The relative error margin of 27.51, 89.84,72.46% and 67.24, 130.84, 166.48% are obtained for 0.1%, 0.01% and 0.001% of the time for 19.8 and 20.73 GHz under vertical and circular polarization respectively from ITU

  13. Satellite (Natural)

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    In its most general sense, any celestial object in orbit around a similar larger object. Thus, for example, the Magellanic Clouds are satellite galaxies of our own Milky Way galaxy. Without qualification, the term is used to mean a body in orbit around a planet; an alternative term is moon. The term natural satellite distinguishes these bodies from artificial satellites—spacecraft placed in orbi...

  14. Basal hypothalamic pituitary adrenal axis activity and hippocampal volumes: the SMART-Medea study.

    Science.gov (United States)

    Knoops, Arnoud J G; Gerritsen, Lotte; van der Graaf, Yolanda; Mali, Willem P Th M; Geerlings, Mirjam I

    2010-06-15

    It has frequently been hypothesized that high levels of glucocorticoids have deleterious effects on the hippocampus and increase risk for cognitive decline and dementia, but no large-scale studies in humans have examined the direct relation between hippocampal volumes and hypothalamic-pituitary-adrenal axis activity. Cross-sectional analyses within the Second Manifestations of ARTerial disease-Magnetic Resonance (SMART)-Medea study, an ancillary study to the SMART-MR study on brain changes on magnetic resonance imaging (MRI) among patients with arterial disease. In 575 patients (mean age 62 +/- 9 years), diurnal cortisol rhythm was assessed with six saliva samples, collected at awakening; at 30, 45, and 60 min thereafter; and at 10 pm and 11 pm. A low dose of dexamethasone (.5 mg) was administered at 11 pm, and saliva was sampled the next morning at awakening. Volumetric measurements of the hippocampus were performed on a three-dimensional fast field echo T1-weighted scan with isotropic voxels. Mean total relative hippocampal volume was 6.0 +/- .7 mL. Linear regression analyses, adjusted for age, sex, vascular risk factors, and global brain atrophy showed that participants with higher evening levels and higher awakening levels after dexamethasone had smaller hippocampal volumes [B per SD (4.2) increase = -.09 mL; 95% confidence interval -.15 to -.03 mL and B per SD (2.5) increase = -.07 mL; 95% confidence interval -.13 to -.01 mL, respectively]. The awakening response was not significantly associated with hippocampal volumes. In this population, higher evening cortisol levels and reduced suppression after dexamethasone were associated with smaller hippocampal volumes, independent of total brain volume. The cortisol response after awakening was not associated with hippocampal volume.

  15. Recent regulatory experience of low-Btu coal gasification. Volume III. Supporting case studies

    Energy Technology Data Exchange (ETDEWEB)

    Ackerman, E.; Hart, D.; Lethi, M.; Park, W.; Rifkin, S.

    1980-02-01

    The MITRE Corporation conducted a five-month study for the Office of Resource Applications in the Department of Energy on the regulatory requirements of low-Btu coal gasification. During this study, MITRE interviewed representatives of five current low-Btu coal gasification projects and regulatory agencies in five states. From these interviews, MITRE has sought the experience of current low-Btu coal gasification users in order to recommend actions to improve the regulatory process. This report is the third of three volumes. It contains the results of interviews conducted for each of the case studies. Volume 1 of the report contains the analysis of the case studies and recommendations to potential industrial users of low-Btu coal gasification. Volume 2 contains recommendations to regulatory agencies.

  16. Mass Deposition Fluxes of Asian Dust to the Bohai Sea and Yellow Sea from Geostationary Satellite MTSAT: A Case Study

    Directory of Open Access Journals (Sweden)

    Qianguang Tu

    2015-11-01

    Full Text Available Windblown dust aerosol plays an important role in marine ecosystems once they are deposited and dissolved. At present, methods for estimating the deposition flux are mainly limited to direct measurements or model outputs. Additionally, satellite remote sensing was often used to estimate the integral dust column concentration (DCC. In this paper, an algorithm is developed to estimate the mass deposition fluxes of Asian dust by satellite. The dust aerosol is identified firstly and then the DCC is derived based on the relationships between the pre-calculated lookup table (LUT and observations from Japanese geostationary Multi-functional Transport Satellites (MTSAT. The LUT is built on the dust cloud and surface parameters by a radiation transfer model Streamer. The average change rate of deposition is derived, which shows an exponential decay dependence on transport time along the pathway. Thus, the deposition flux is acquired via integrating the hourly deposition. This simple algorithm is applied to a dust storm that occurred in the Bohai Sea and Yellow Sea from 1 to 3 March 2008. Results indicate that the properties of the dust cloud over the study area changed rapidly and the mass deposition flux is estimated to be 2.59 Mt.

  17. Effect of cataract surgery volume constraints on recently graduated ophthalmologists: a population-based cohort study

    Science.gov (United States)

    Campbell, Robert J.; El-Defrawy, Sherif R.; Bell, Chaim M.; Gill, Sudeep S.; Hooper, Philip L.; Whitehead, Marlo; Campbell, Erica de L.P.; Nesdole, Robert; Warder, Daniel; ten Hove, Martin

    2017-01-01

    BACKGROUND: Across Canada, graduates from several medical and surgical specialties have recently had difficulty securing practice opportunities, especially in specialties dependent on limited resources such as ophthalmology. We aimed to investigate whether resource constraints in the health care system have a greater impact on the volume of cataract surgery performed by recent graduates than on established physicians. METHODS: We used population-based administrative data from Ontario for the period Jan. 1, 1994, to June 30, 2013, to compare health services provided by recent graduates and established ophthalmologists. The primary outcome was volume of cataract surgery, a resource-intensive service for which volume is controlled by the province. RESULTS: When cataract surgery volume in Ontario entered a period of government-mandated zero growth in 2007, the mean number of cataract operations performed by recent graduates dropped significantly (−46.37 operations/quarter, 95% confidence interval [CI] −62.73 to −30.00 operations/quarter), whereas the mean rate for established ophthalmologists remained stable (+5.89 operations/quarter, 95% CI 95% CI −1.47 to +13.24 operations/quarter). Decreases in service provision among recent graduates did not occur for services without volume control. The proportion of recent graduates providing exclusively cataract surgery increased over the study period, and recent graduates in this group were 5.24 times (95% CI 2.15 to 12.76 times) more likely to fall within the lowest quartile for cataract surgical volume during the period of zero growth in provincial cataract volume (2007–2013) than in the preceding period (1996–2006). INTERPRETATION: Recent ophthalmology graduates performed many fewer cataract surgery procedures after volume controls were implemented in Ontario. Integrated initiatives involving multiple stakeholders are needed to address the issues facing recently graduated physicians in Canada. PMID:27920012

  18. Depression, hypothalamic pituitary adrenal axis, and hippocampal and entorhinal cortex volumes--the SMART Medea study.

    Science.gov (United States)

    Gerritsen, Lotte; Comijs, Hannie C; van der Graaf, Yolanda; Knoops, Arnoud J G; Penninx, Brenda W J H; Geerlings, Mirjam I

    2011-08-15

    Structural brain changes have often been found in major depressive disorder (MDD), and it is thought that hypothalamic-pituitary-adrenal (HPA) axis hyperactivity may explain this relation. We investigated the association of MDD and history of depression with hippocampal and entorhinal cortex volumes and whether HPA axis activity explained this association. In 636 participants with a history of atherosclerotic disease (mean age 62 ± 9 years, 81% male) from the second Manifestation of ARTerial disease-Memory depression and aging (SMART-Medea) study, a 12-month diagnosis of MDD and history of depression were assessed. Age of first depressive episode was classified into early-onset depression (< 50 years) and late-onset depression (≥ 50 years). HPA axis regulation was assessed by four morning saliva samples, two evening samples, and one awakening sample after .5 mg dexamethasone. Hippocampus and entorhinal cortex volume were manually outlined on three-dimensional T1-weighted magnetic resonance images. General linear models adjusted for demographics, vascular risk, antidepressant use, and white matter lesions showed that ever having had MDD was associated with smaller hippocampal volumes but not with entorhinal cortex volumes. Remitted MDD was related to smaller entorhinal cortex volumes (p < .05). Participants with early-onset depression had smaller hippocampal volumes than those who were never depressed (p < .05), whereas participants with late-onset depression had smaller entorhinal cortex volumes (p < .05). HPA axis activity did not explain these differences. We found differential associations of age of onset of depression on hippocampal and entorhinal cortex volumes, which could not be explained by alterations in HPA axis regulation. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  19. Effect of water coffee extract on kidney volume (a stereological study

    Directory of Open Access Journals (Sweden)

    Farzaneh Dehghani

    2013-09-01

    Full Text Available Background: Coffee is a traditional drinking used by most of the people around the world. Overuse of coffee leads to many side effects on body. In this study, the effect of different doses of coffee extract on kidney volume was studied by the stereological method. Material and Methods: Sixty spragu-dawley male rats were divided into 6 groups. Control group was given tap water (0.5ml and experimental groups were given coffee extract orally for 14 days with doses (0.125, 0.25, 0.5, 1, 1.5gr/kg with the same volume of control group. Then rats were anesthetized (with ether, sacrificed and their right kidneys were removed, fixed, tissue processed and stained with H&E. The 5µm slides were studied by Cavalieri principle. Results: Higher doses of water coffee extract were associated with decreased kidney volume and volumes of glomerules but in lower doses it increased related to control group. Conclusion: It seems that, high doses of coffee has side effect on kidneyand reduces volume of kidney and its glomerules. However further studies are required to confirm this research.

  20. Study on Dynamic Resource Management about the Satellite Communication Network%卫星通信网络资源管理研究

    Institute of Scientific and Technical Information of China (English)

    贺祥

    2016-01-01

    In this paper we study the capacity request queue scheduling mechanism based on the distinct service QoS in view of RCST terminals;In view of the network control center,we study a dynamic resource management based on volume change trend prediction method. The concolusions of this paper can be used in the satellite communication network between terminal and centre station in interactive business requests and resource allocation.%本文针对RCST终端,研究了基于区分服务QoS的容量请求排队调度机制;针对网络控制中心,研究了一种基于业务量变化趋势预测的动态资源管理方法,可用于IP化卫星通信网络中终端与中心站之间交互式的业务请求与资源分配。

  1. Geosynchronous platform definition study. Volume 6: Geosynchronous program evaluation and recommendations

    Science.gov (United States)

    Myers, H. L.

    1973-01-01

    The programmatic analyses conducted to achieve the objectives of the study are presented. The characteristics are examined of alternate geosynchronous programs based on servicing concepts, geosynchronous platform configurations, and equipment definitions which have evolved during the study. The logistics support necessary to carry out programs using these systems is defined considering alternate approaches for on-orbit servicing. The costs of the resultant programs are then determined and the alternate program approaches compared. Conventional programs with expendable satellites are also defined to the extent necessary to permit comparison with on-orbit serviced platform programs.

  2. Realtime or Delayed Tele-Echography Using (A) a Robotic Arm, ISDN or Satellite Lines, (B) a Volumic Echographic Capture Mode and Internet (Application to Abdomen and Fetus)

    Science.gov (United States)

    Arbeille, Ph.; Cloppet, F.; Boucher, A.; Capri, A.; Vincent, N.

    2008-06-01

    Objective: to test (a) the tele-echography in realtime based on the use of a robotic arm, (b) the delayed tele echography using a volumic echographic capture and delayed processing. Method: A dedicated robotic arm (ESTELE) holding a real ultrasound probe is remotely controlled from the expert site with a fictive probe, and reproduces on the real probe all the movements of the expert hand. A dedicated motorized probe holder (TILTER) was used for tilting a 2D probe from -45 to +45°. Results: During fetal robotized Tele-echography (n=50) the expert was able to visualize and measure the fetal structures in 95% of the cases, while during abdomen echography (n=87) the expert visualized the main organs and lesions in 87% of the cases. The mean duration of the robotized tele echography session for one patient was 20+/-10 min. The delayed echography using the TILTER was tested on 40 patients. The organs were adequately visualized in 85% of the cases after 3 capture per organ. The average time from the first capture until the diagnostic was delivered was 40+/-10 minutes. Conclusion: Realtime or delayed Tele-echography provide similar information as direct examination in at least 85% of the cases. No false diagnostic was reported.

  3. Integrated use of satellite images, DEMs, soil and substrate data in studying mountainous lands

    Science.gov (United States)

    Giannetti, Fabio; Montanarella, Luca; Salandin, Roberto

    A method based on the integration into a GIS of satellite images of different spatial resolution (Landsat TM and SPOT), Digital Elevation Models, geo-lithological maps and some soil-landscape data was developed and applied to a test area on a sector of the Italian northwestern Alps in the Piemonte region (Pellice, Po, Varaita and Maira valleys southwest of Torino). The main working steps performed (using GIS software) in this area were: (1) acquisition of geo-lithological and geomorphological maps available and a first definition of homogeneous zones obtained by joining different classes with pedogenic criteria; (2) processing and classification of satellite images to define homogeneous areas with reference to prevailing land cover, land use pattern, relief shape and spectral characters; (3) integration of the previous two layers to obtain a first set of cartographic units showing a distinctive and often repetitive pattern of land form, land cover and parent material; and (4) processing DEMs (slope and aspect), soil or soil-landscape data in order to refine data and characterise the units. The resulting cartographic units were superimposed on a soil-landscape map realised by means of stereoscopic interpretation of aerial photographs by IPLA at the same scale (1:250,000). This comparison was used to verify the correctness of the satellite image processing steps and consistency with the map scale used. A larger scale application was also developed for grassland at 1:50,000 scale to demonstrate the practical use of remote sensing and GIS data in assisting mountainous land development.

  4. Estimating boundary currents from satellite altimetry: A case study for the east coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Durand, F.; Shankar, D.; Birol, F.; Shenoi, S.S.C.

    in our area (Chelton et al., 1998). We can see that the other dynamical effects not accounted for by the linear theory tend to spread the coastal trapping of the energy in the offshore direction. About 200 km off the coast, the power of the annual... by means of a 3.notdef.g0002 filter, where .notdef.g0002 is the standard deviation of the original along track record. One value of .notdef.g0002 is computed per satellite cycle and per corrective parameter, so as to account for the natural temporal...

  5. Assessment of Satellite-based Precipitation Products (TRMM) in Hydrologic Modeling: Case Studies from Northern Morocco

    Science.gov (United States)

    EL kadiri, R.; Milewski, A.; Durham, M.

    2012-12-01

    Precipitation is the most important forcing parameter in hydrological modeling, yet it is largely unknown in the arid Middle East. We assessed the magnitude, probability of detection, and false alarm rates of various rainfall satellite products (e.g., TRMM, RFE2.0) compared to in situ gauge data (~79 stations) across the Our Er Rbia, Sebou, and Melouya Watersheds in Northern Morocco. Precipitation over the area is relatively high with an average of ~400mm/year according to TRMM (1998-2008). The existing gauges indicate that the average annual precipitation across the Tadla and Coastal Plains region is 260mm/year and 390mm/year across the Atlas Mountains. Following the assessment of satellite products against in situ gauge data, we evaluated the effects (e.g., runoff and recharge amounts) of using satellite driven hydrologic models using SWAT. Specifically, we performed a four-fold exercise: (1) The first stage focused on the analysis of the rainfall products; (2) the second stage involved the construction of a rainfall-runoff model using gauge data; (3) the third stage entailed the calibration of the model against flow gauges and/or dams storage variability, and (4) model simulation using satellite based rainfall products using the calibrated parameters from the initial simulation. Results suggest the TRMM V7 has a much better correlation with the field data over the Oum Er Rbia watershed. The Correlation E (Nash-Suncliffe coefficient) has a positive value of 0.5, while the correlation coefficient of TRMM V6 vs. gauges data is a negative value of -0.25. This first order evaluation of the TRMM V7 shows the new algorithm has partially overcame the underestimation effect in the semi-arid environments. However, more research needs to be done to increase the usability of TRMM V7 in hydrologic models. Low correlations are most likely a result of the following: (1) snow at the high elevations in the Oum Er Rbia watershed, (2) the ocean effect on TRMM measurements along

  6. Numerical and Experimental Study for a Beam System with Local Unilateral Contact Modeling Satellite Solar Arrays

    CERN Document Server

    Hazim, Hamad; Ferguson, Neil

    2009-01-01

    The mass reduction of satellite solar arrays results in significant panel flexibility, so possibly striking one another dynamically leading ultimately to structural damage. To prevent this, rubber snubbers are mounted at well chosen points of the structure and they act as one sided linear spring; as a negative consequence, the dynamic of these panels becomes nonlinear. The finite element approximation is used to solve partial differential equations governing the structural dynamic. The models are validated and adjusted with experiments done in the ISVR laboratory, Southampton university.

  7. Emergency Locator Signal Detection and Geolocation Small Satellite Constellation Feasibility Study

    OpenAIRE

    Gunderson, Adam; Byers, Celena; Klumpar, David

    2011-01-01

    Aircraft Emergency Locator Transmitters (ELTs) are vital in helping search and rescue (SAR) teams in locating downed aircraft. Currently there are two types of ELTs available; one transmits at 121.5 MHz and the other at 406 MHz. The transmitters operating at 121.5 MHz have since been abandoned by satellite tracking systems even though these beacons are still available for non-commercial aviation use. Space based receiver decommissioning of 121.5 MHz systems was largely due to an inefficiency ...

  8. How reliable are satellite precipitation estimates for driving hydrological models: a verification study over the Mediterranean area

    Science.gov (United States)

    Camici, Stefania; Ciabatta, Luca; Massari, Christian; Brocca, Luca

    2017-04-01

    Floods are one of the most common and dangerous natural hazards, causing every year thousands of casualties and damages worldwide. The main tool for assessing flood risk and reducing damages is represented by hydrologic early warning systems that allow to forecast flood events by using real time data obtained through ground monitoring networks (e.g., raingauges and radars). However, the use of such data, mainly rainfall, presents some issues firstly related to the network density and to the limited spatial representativeness of local measurements. A way to overcome these issues may be the use of satellite-based rainfall products (SRPs) that nowadays are available on a global scale at ever increasing spatial/temporal resolution and accuracy. However, despite the large availability and increased accuracy of SRPs (e.g., the Tropical Rainfall Measurement Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA); the Satellite Application Facility on Support to Operational Hydrology and Water Management (H-SAF); and the recent Global Precipitation Measurement (GPM) mission), remotely sensed rainfall data are scarcely used in hydrological modeling and only a small number of studies have been carried out to outline some guidelines for using satellite data as input for hydrological modelling. Reasons may be related to: 1) the large bias characterizing satellite precipitation estimates, which is dependent on rainfall intensity and season, 2) the spatial/temporal resolution, 3) the timeliness, which is often insufficient for operational purposes, and 4) a general (often not justified) skepticism of the hydrological community in the use of satellite products for land applications. The objective of this study is to explore the feasibility of using SRPs in a lumped hydrologic model (MISDc, "Modello Idrologico Semi-Distribuito in continuo", Masseroni et al., 2017) over 10 basins in the Mediterranean area with different sizes and physiographic characteristics. Specifically

  9. Geosynchronous Microwave Atmospheric Sounding Radiometer (MASR) feasibility studies. Volume 1: Management summary

    Science.gov (United States)

    1978-01-01

    The mission of the microwave atmospheric sounding radiometer (MASR) is to collect data to aid in the observation and prediction of severe storms. The geosynchronous orbit allows the continuous atmospheric measurement needed to resolve mesoscale dynamics. The instrument may operate in conjunction with this document, Volume 1 - Management, which summarizes the highlights of final reports on both the radiometer instrument and antenna studies. The radiometer instrument summary includes a synopsis of Volume 2 - Radiometer Receiver Feasibility, including design, recommended configuration, performance estimates, and weight and power estimates. The summary of the antenna study includes a synopsis of Volume 3 - Antenna Feasibility, including preliminary design tradeoffs, performance of selected design, and details of the mechanical/thermal design.

  10. The surprising inefficiency of dwarf satellite quenching

    CERN Document Server

    Wheeler, Coral; Cooper, Michael C; Boylan-Kolchin, Mike; Bullock, James S

    2014-01-01

    We study dwarf satellite galaxy quenching using observations from the Geha et al. (2012) NSA/SDSS catalog together with LCDM cosmological simulations to facilitate selection and interpretation. We show that fewer than 30% of dwarfs (M* ~ 10^8.5-10^9.5 Msun) identified as satellites within massive host halos (Mhost ~ 10^12.5-10^14 Msun) are quenched, in spite of the expectation from simulations that half of them should have been accreted more than 6 Gyr ago. We conclude that whatever the action triggering environmental quenching of dwarf satellites, the process must be highly inefficient. We investigate a series of simple, one-parameter quenching models in order understand what is required to explain the low quenched fraction and conclude that either the quenching timescale is very long (> 9.5 Gyr, a "slow starvation" scenario) or that the environmental trigger is not well matched to accretion within the virial volume. We discuss these results in light of the fact that most of the low mass dwarf satellites in ...

  11. Study on hippocampal volume with quantitative 3T magnetic resonance imaging in Chinese patients with epilepsy

    Institute of Scientific and Technical Information of China (English)

    GAO Mei-chun; LU Qin-chi; LI Yan-sheng; SHEN Jia-lin

    2012-01-01

    Background It was still rare for the quantitative magnetic resonance imaging (MRI) research of regional changes in hippocampus sclerosis (HS) in Chinese patients with epilepsy.This study aimed to study the hippocampal volumes (HVs)with quantitative MRI measurement in Chinese patients with epilepsy.Methods Forty-six Chinese patients with epilepsy (intractable epilepsy (IE),n=21; non-intractable epilepsy (NIE),n=25)and 25 normal controls were collected between July 2007 and March 2008.All of the subjects underwent a 3T high-resolution MRI with oblique coronal thin sections oriented perpendicular to the hippocampal long axis.Hippocampal structures were assessed by visual detection,and HVs were quantitatively studied with a Picture Archiving and Communication System (PACS).Results Our study suggested that there was no significant difference in gender (P >0.05) while the right hippocampal head volume (HHV),hippocampal body volume (HBV),and the whole hippocampal volume (HCV) were greater than the left one (P <0.05),but no significant difference was found in bilateral hippocampal tail volume (HTV) (P >0.05) in normal controls.That unilateral/diffuse (64%/21%) and bilateral/focal (86%/20%) hippocampal atrophy (HA)were significant in IE and NIE patients,respectively.Anterior hippocampus,especially HHV (26% in IE and 20% in NIE) and HBV (29% in IE and 12% in NIE),had more significant atrophy than the HTV (5% in IE and 0% in NIE) in patients with epilepsy.Conclusion By assessing the volumes of the regional hippocampus with 3T MRI,we could better define the range and distribution of HS,since regional or subtle changes in HVs could be detected earlier with 3T MRI.

  12. A study of finite volume effect on the multiple-frequencies coherence of VHF radar

    Science.gov (United States)

    Chen, Tsai-Yuan; Chu, Yen-Hsyang

    1993-08-01

    In the past few years, the technique of frequency domain interferometry (FDI) has been developed on VHF radar. By using this technique, the characteristics of a very thin atmospheric lay structure, which is embedded in the radar volume and cannot be solved by conventional VHF radar with only one operational frequency, can be determined through the calculation of the coherence and the phase from the two echo signals with different operational frequencies. According to FDI theory, assuming that the range and antenna beam weighting effect can be ignored, the coherence will approach zero if the layer thickness is fairly greater than the radar volume. However, in this study, it will be shown that if a rectangular pulse is transmitted and the atmospheric refractivity irregularities are distributed uniformly in the radar volume, that is, there is no narrow layer structure existing in the scattering volume, the coherence of two signals with different operational frequencies is still high and its behavior can be described by the equation C is approximately equal to Sinc((Delta)k L)/(l + N/S), where C is the coherence, Delta K is the wavenumber difference between two carrier frequencies, L is the effective scale of scattering volume, and N/S is the noise-to-signal power ratio. This feature can be interpreted physically by the finite volume filtering effect on the turbulent wavenumber spectrum. This theoretical prediction has been compared with the FDI experiments carried out by the Chung-Li VHF radar, and the results are quite reasonable. Thus, it is suggested that when the FDI technique is applied to estimate the thickness and the position of a thin layer, the finite volume filtering effect should be taken into account.

  13. Evaluating Satellite Products for Precipitation Estimation in Mountain Regions: A Case Study for Nepal

    Directory of Open Access Journals (Sweden)

    Tarendra Lakhankar

    2013-08-01

    Full Text Available Precipitation in mountain regions is often highly variable and poorly observed, limiting abilities to manage water resource challenges. Here, we evaluate remote sensing and ground station-based gridded precipitation products over Nepal against weather station precipitation observations on a monthly timescale. We find that the Tropical Rainfall Measuring Mission (TRMM 3B-43 precipitation product exhibits little mean bias and reasonable skill in giving precipitation over Nepal. Compared to station observations, the TRMM precipitation product showed an overall Nash-Sutcliffe efficiency of 0.49, which is similar to the skill of the gridded station-based product Asian Precipitation-Highly Resolved Observational Data Integration Towards Evaluation of Water Resources (APHRODITE. The other satellite precipitation products considered (Global Satellite Mapping of Precipitation (GSMaP, the Climate Prediction Center Morphing technique (CMORPH, Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS were less skillful, as judged by Nash-Sutcliffe efficiency, and, on average, substantially underestimated precipitation compared to station observations, despite their, in some cases, higher nominal spatial resolution compared to TRMM. None of the products fully captured the dependence of mean precipitation on elevation seen in the station observations. Overall, the TRMM product is promising for use in water resources applications.

  14. VIS-NIR Spectrophotometric Study of the Saturnian icy Satellites by Cassini-VIMS

    Science.gov (United States)

    Filacchione, G.; Capaccioni, F.; Tosi, F.; Coradini, A.; Cerroni, P.; Adriani, A.; McCord, T. B.; Baines, K. H.; Bellucci, G.; Brown, R. H.; Bibring, J.; Buratti, B. J.; Clark, R. N.; Combes, M.; Cruikshank, D. P.; Formisano, V.; Jaumann, R.; Langevin, Y. G.; Matson, D. L.; Mennella, V.; Nelson, R. M.; Nicholson, P. D.; Sicardy, B.; Sotin, C.

    2007-12-01

    After the first three years of the nominal mission aboard the Cassini probe the VIMS (Visual and Infrared Mapping Spectrometer) experiment has collected more than one thousand useful full-disk observations of both regular (Mimas, Enceladus, Tethys, Dione, Rhea, Hyperion, Iapetus, Phoebe) and minor (Atlas, Prometheus, Pandora, Janus, Epimetheus, Telesto, Calypso) icy moons of Saturn. These data, acquired from a variety of distances and inclinations from the equatorial plane, with different phase angles and hemispheric coverage, are analyzed by using several spectroscopic indicators (I/F continuum level, slopes, bands strengths) in order to identify analogies and differences in the compositional units of satellites and derive the phase curves at different longitudes; many observations acquired close to zero phase angle allow us to measure the opposition surge effect on several satellites. Concerning the composition we have derived the distribution of the water ice abundance and grain size from the almost pure icy surfaces of Enceladus and Calypso to the organic rich Hyperion, Iapetus and Phoebe. We report about the differences observed in the CO2 band position which is shifted at shorter wavelengths on Hyperion respect to Phoebe and Iapetus; this effect is probably related to a different distribution of clathrates on these icy surfaces. This research was completed thanks to the support of the Italian Space Agency (ASI).

  15. Sea surface wind perturbations over the Kashevarov Bank of the Okhotsk Sea: a satellite study

    Directory of Open Access Journals (Sweden)

    T. I. Tarkhova

    2011-02-01

    Full Text Available Sea surface wind perturbations over sea surface temperature (SST cold anomalies over the Kashevarov Bank (KB of the Okhotsk Sea are analyzed using satellite (AMSR-E and QuikSCAT data during the summer-autumn period of 2006–2009. It is shown, that frequency of cases of wind speed decreasing over a cold spot in August–September reaches up to 67%. In the cold spot center SST cold anomalies reached 10.5 °C and wind speed lowered down to ~7 m s−1 relative its value on the periphery. The wind difference between a periphery and a centre of the cold spot is proportional to SST difference with the correlations 0.5 for daily satellite passes data, 0.66 for 3-day mean data and 0.9 for monthly ones. For all types of data the coefficient of proportionality consists of ~0.3 m s−1 on 1 °C.

  16. Measuring snow and glacier ice properties from satellite

    Science.gov (United States)

    KöNig, Max; Winther, Jan-Gunnar; Isaksson, Elisabeth

    2001-02-01

    Satellite remote sensing is a convenient tool for studying snow and glacier ice, allowing us to conduct research over large and otherwise inaccessible areas. This paper reviews various methods for measuring snow and glacier ice properties with satellite remote sensing. These methods have been improving with the use of new satellite sensors, like the synthetic aperture radar (SAR) during the last decade, leading to the development of new and powerful methods, such as SAR interferometry for glacier velocity, digital elevation model generation of ice sheets, or snow cover mapping. Some methods still try to overcome the limitations of present sensors, but future satellites will have much increased capability, for example, the ability to measure the whole optical spectrum or SAR sensors with multiple polarization or frequencies. Among the methods presented are the satellite-derived determination of surface albedo, snow extent, snow volume, snow grain size, surface temperature, glacier facies, glacier velocities, glacier extent, and ice sheet topography. In this review, emphasis is put on the principles and theory of each satellite remote sensing method. An extensive list of references, with an emphasis on studies from the 1990s, allows the reader to delve into specific topics.

  17. Penafsiran Volume Pohon Pinus merkusii melalui Foto Udara (Studi Kasus BKPH Majenang, KPH Banyumas Barat

    Directory of Open Access Journals (Sweden)

    Sahid -

    2013-01-01

    Full Text Available Interpretation of  Stock Volume of Pinus merkusii  using Aerial Photographs (Case Study in BKPH Majenang, West Banyumas FMU The study aims to compile and analyse the growing stock volume of Pinus merkusii by using stand parameter measured through aerial photographs. The study was conducted by using black-white panchromatic aerial photographs produced in 2005 and the scale was 1 : 20,000. The study was conducted in Pinus merkusii taping plots in the Majenang BKPH, under the forest districts of west Banyumas, Perum Perhutani using tree height, crown diameter and number of trees per hectare as parameters. Data analysis was done to define the relationship among these parameters in regression equation. The steps of the study were defining measurement plots in aerial photographs, measurement of stand parameters in the aerial photographs and field observation. Data analysis was performed using micro computer. As a result, the regression equation for each location as follows: V = 72,415 – 0,231 N + 35,242 H – 24,454D – 0,923 (N x D, with the determination coefficient was 0,789 and the significance of 95%. Where: V = growing stock volume (m3, N = the number of trees per hectare, H = tree height (m and D = crown diameter (m. It was concluded that number of tree per hectare, tree height and crown diameter were good predictors for standing stock volume of Pinus merkusii.

  18. Anions Govern Cell Volume: A Case Study of Relative Astrocytic and Neuronal Swelling in Spreading Depolarization.

    Directory of Open Access Journals (Sweden)

    Niklas Hübel

    Full Text Available Cell volume changes are ubiquitous in normal and pathological activity of the brain. Nevertheless, we know little about the dynamics of cell and tissue swelling, and the differential changes in the volumes of neurons and glia during pathological states such as spreading depolarizations (SD under ischemic and non-ischemic conditions, and epileptic seizures. By combining the Hodgkin-Huxley type spiking dynamics, dynamic ion concentrations, and simultaneous neuronal and astroglial volume changes into a comprehensive model, we elucidate why glial cells swell more than neurons in SD and the special case of anoxic depolarization (AD, and explore the relative contributions of the two cell types to tissue swelling. Our results demonstrate that anion channels, particularly Cl-, are intrinsically connected to cell swelling and blocking these currents prevents changes in cell volume. The model is based on a simple and physiologically realistic description. We introduce model extensions that are either derived purely from first physical principles of electroneutrality, osmosis, and conservation of particles, or by a phenomenological combination of these principles and known physiological facts. This work provides insights into numerous studies related to neuronal and glial volume changes in SD that otherwise seem contradictory, and is broadly applicable to swelling in other cell types and conditions.

  19. Scientific Satellites

    Science.gov (United States)

    1967-01-01

    followed Hale’s into orbit. In 1879, Jules Verne wrote about launching small satellites with a gun possessing a muzzle velocity of 10 000 m/sec (ref. 3...was activated in 1950.11 It was located only a few tens of miles from the spot where Jules Verne had his Baltimore Gun Club fire a manned projectile to...principle, satellites can be launched by a single impulse applied at the Earth’s surface-say, with a large cannon, & la Jules Verne (sec. 8-3). In

  20. Role of Indian remote sensing imaging satellites for the Antarctic monitoring and mapping: a case study around Indian Antarctic research stations

    Science.gov (United States)

    Jayaprasad, P.; Mehra, Raghav; Chawla, Saket; Rajak, D. Ram; Oza, Sandip R.

    2016-05-01

    Antarctic research station's existence largely depend on the supply of fuel, food and other commodities through Antarctic Scientific Expedition using ship voyage. Safer Ship Navigation demands high resolution satellite monitoring of the ice conditions which varies from 30 km to 200 km from the Antarctic coast of Research stations. During the last couple of years Indian Satellites play a major role in safer ship navigation in sea ice regions of the Arctic and the Antarctic. Specifically Indian Scientific Expedition to the Antarctica (ISEA) through National Centre for Antarctic and Oceanic Research (NCAOR) is one of the beneficiaries for safer ship navigation using information derived from Indian Satellite data. Space Applications Centre, Indian Space Research Organisation (SAC-ISRO) is providing Sea Ice Advisories for the safer optimum entry and exit for the expedition ship at two of the Research stations Bharati and Maitri. Two of the Indian Satellites namely Radar Imaging Satellite-1 (RISAT-1) and ResourceSAT-2 (RS-2) are the two major workhorses of ISRO for monitoring and mapping of the Antarctic terrain. The present study demonstrate the utilisation potential of these satellite images for various Polar Science Applications. Mosaic of the Antarctic Terrain was generated from RISAT-1 CRS data. The preliminary results of the mosaic from CRS- circular polarisation data is presented. Demonstration of the study is extended for other applications such as change detection studies, safer ship navigation and extreme events of Antarctica. The use of multi resolution multi sensor data is also shown in the study.

  1. Evaluation of volume vascularization index and flow index: a phantom study.

    NARCIS (Netherlands)

    Schulten-Wijman, M.J.; Struijk, P.C.; Brezinka, C.; Jong, N De; Steegers, E.A.P.

    2008-01-01

    OBJECTIVES: Three-dimensional (3D) power Doppler ultrasonography provides indices to quantify moving blood within a volume of interest (e.g. ovary, endometrium, tumor or placenta). The purpose of this study was to determine the influence of ultrasound instrument settings on vascularization index (VI

  2. Evaluation of volume vascularization index and flow index: A phantom study

    NARCIS (Netherlands)

    M.J.N.C. Schulten-Wijman; P.C. Struijk (Pieter); C.A. Brezinka (Christoph); N. de Jong (Nico); R.P.M. Steegers-Theunissen (Régine)

    2008-01-01

    textabstractObjectives Three-dimensional (3D) power Doppler ultrasonography provides indices to quantify moving blood within a volume of interest (e.g. ovary, endometrium, tumor or placenta). The purpose of this study was to determine the influence of ultrasound instrument settings on vascularizatio

  3. Preface to the 8th Volume of The Interdisciplinary Journal of International Studies (IJIS)

    DEFF Research Database (Denmark)

    Juego, Bonn

    2012-01-01

    This 8th volume of The Interdisciplinary Journal of International Studies (IJIS) is a product of the continuing revitalization process that the journal has undertaken since 2010. Very significant recent developments in this process are the IJIS’ successful listing in the Directory of Open Access ...

  4. Inertial Fusion Energy reactor design studies: Prometheus-L, Prometheus-H. Volume 2, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Waganer, L.M.; Driemeyer, D.E.; Lee, V.D.

    1992-03-01

    This report contains a review of design studies for Inertial Confinement reactor. This second of three volumes discussions is some detail the following: Objectives, requirements, and assumptions; rationale for design option selection; key technical issues and R&D requirements; and conceptual design selection and description.

  5. Operation of Wastewater Treatment Plants: A Field Study Training Program. Volume II. Second Edition.

    Science.gov (United States)

    California State Univ., Sacramento. Dept. of Civil Engineering.

    This manual was prepared by experienced wastewater collection system workers to provide a home study course to develop new qualified workers and expand the abilities of existing workers. This volume emphasizes material needed by intermediate-level operators and stresses the operation and maintenance of conventional treatment plants. This volume…

  6. Operation of Wastewater Treatment Plants: A Field Study Training Program. Volume I. Second Edition.

    Science.gov (United States)

    California State Univ., Sacramento. Dept. of Civil Engineering.

    This manual was prepared by experienced wastewater collection system workers to provide a home study course to develop new qualified workers and expand the abilities of existing workers. This volume is directed primarily towards entry-level operators and the operators of ponds, package plants, or small treatment plants. Ten chapters examine the…

  7. HPG-axis hormones during puberty : A study on the association with hypothalamic and pituitary volumes

    NARCIS (Netherlands)

    Peper, Jiska S.; Brouwer, Rachel M.; van Leeuwen, Marieke; Schnack, Hugo G.; Boomsma, Dorret I.; Kahn, Rene S.; Pol, Hilleke E. Hulshoff

    2010-01-01

    Objective: During puberty, the hypothalamus-pituitary-gonadal (HPG) axis is activated, leading to increases in luteinizing hormone (LH), follicle stimulating hormone (FSH) and sex steroids (testosterone and estradiol) levels. We aimed to study the association between hypothalamic and pituitary volum

  8. German Studies in the United States: Assessment and Outlook. Monatshefte Occasional Volume Number 1.

    Science.gov (United States)

    Lohnes, Walter F. W., Ed.; Nollendorfs, Valters, Ed.

    This volume focuses on two principal aspects of German studies in the United States: (1) an assessment of the German-teaching profession from primary to graduate school, with attention to its "raison d'etre" in the present academic, social, and cultural situation, as well as its structures, aims, and personnel; and (2) strategies for survival and…

  9. Global Spent Fuel Logistics Systems Study (GSFLS). Volume 2A. GSFLS visit findings (appendix). Interim report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-01-31

    This appendix is a part of the interim report documentation for the Global Spent Fuel Logistics System (GSFLS) study. This appendix provides the legal/regulatory reference material, supportive of Volume 2 - GSFLS Visit Finding and Evaluations; and certain background material on British Nuclear Fuel Limited (BNFL).

  10. Study of Traffic Volume and Level of Service of Panjab University

    Directory of Open Access Journals (Sweden)

    Chandigarh Bhavneet Singh,

    2015-07-01

    Full Text Available A significant effort has been made in order to study the Traffic Volume of Panjab University Campus, Chandigarh. Established in 1882, Panjab University is one of the oldest universities in India. As one of the most renowned Universities in India, Panjab University itself attracts a lot of vehicular population. The Panjab University itself becomes a major traffic generator in a way. Campus is large and contains places to work, learn, socialize and live each with its own trip purpose. In recent years, usage of automobiles on campus has increased considerably. In addition to going to class, students also are likely to use vehicles for employment, recreation, shopping and social activities. The objective of the study is to analyze the prevailing traffic conditions on the University roads. Traffic Volume study is carried out in the campus and existing level of service is calculated.Due to mixed nature of traffic it gets difficult to accommodate all the kinds of traffic on these roads. The basic problem arises during the peak hours of the day when the traffic volume is highest on the road. The volume study were done at Gate no.1 and Gate no. 2 which are the major entry points in the University. The data was analyzed for the peak hour of traffic.

  11. Evaluation of Development and Changes in Land Use using Different Satellite Image Processing and Remote Sensing Techniques (Case Study: Kermanshah, Iran)

    OpenAIRE

    2013-01-01

    Currently the largest city in the western Iran, Kermanshah enjoys fast growing trend because of its strategic location. Remote sensing and satellite imagery are well suited for assessing the changes in land use over different time periods. In this study, satellite images from Landsat TM sensor and ETM sensor have been prepared during 1987 and 2007 as geometric and radiometric corrections have been made to them. The process was followed by selecting the best combination of false color by using...

  12. A Comparative Study of Pituitary Volume Variations in MRI in Acute Onset of Psychiatric Conditions.

    Science.gov (United States)

    Soni, Brijesh Kumar; Joish, Upendra Kumar; Sahni, Hirdesh; George, Raju A; Sivasankar, Rajeev; Aggarwal, Rohit

    2017-02-01

    The growing belief that endocrine abnormalities may underlie many mental conditions has led to increased use of imaging and hormonal assays in patients attending to psychiatric OPDs. People who are in an acute phase of a psychiatric disorder show Hypothalamic Pituitary Adrenal (HPA) axis hyperactivity, but the precise underlying central mechanisms are unclear. To assess the pituitary gland volume variations in patients presenting with new onset acute psychiatric illness in comparison with age and gender matched controls by using MRI. The study included 50 patients, with symptoms of acute psychiatric illness presenting within one month of onset of illness and 50 age and gender matched healthy controls. Both patients and controls were made to undergo MRI of the Brain. A 0.9 mm slices of entire brain were obtained by 3 dimensional T1 weighted sequence. Pituitary gland was traced in all sagittal slices. Anterior pituitary and posterior pituitary bright spot were measured separately in each slice. Volume of the pituitary (in cubic centimetre- cm(3)) was calculated by summing areas. Significance of variations in pituitary gland volumes was compared between the cases and controls using Analysis of Covariance (ANOVA). There were significantly larger pituitary gland volumes in the cases than the controls, irrespective of psychiatric diagnosis (ANOVA, f=15.56; p=0.0002). Pituitary volumes in cases were 15.36% (0.73 cm(3)) higher than in controls. There is a strong likelihood of HPA axis overactivity during initial phase of all mental disorders along with increased pituitary gland volumes. Further studies including hormonal assays and correlation with imaging are likely to provide further insight into neuroanatomical and pathological basis of psychiatric disorders.

  13. Fusion between Satellite and Geophysical images in the study of Archaeological Sites

    Science.gov (United States)

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

    2012-12-01

    In this work various image fusion techniques are used between one satellite (Quickbird) and one geophysical (electric resistivity) image to create various combinations with higher information content than the two original images independently. The resultant images provide more information about possible buried archaeological relics. The examined archaeological area is located in mainland Greece near the city of Boetia at the acropolis of Gla. The acropolis was built on a flat-topped bedrock outcrop at the north-eastern edge of the Kopais basin. When Kopais was filled with water, Glas was emerging as an island. At the end of 14th century the two palaces of Thebes and Orchomenos jointly utilized a large scale engineering project in order to transform the Kopais basin into a fertile plain. They used the acropolis to monitor the project, and as a warehouse to storage the harvest. To examine the Acropolis for potential archaeological remnants we use one Quickbird satellite image that covers the surrounding area of Gla. The satellite image includes one panchromatic (8532x8528 pixels) and one multispectral (2133x2132 pixels) image, collected on 30th of August 2011, covering an area of 20 square kilometers. On the other hand, geophysical measurements were performed using the electric resistivity method to the south west part of the Acropolis. To combine these images we investigate mean-value fusion, wavelets fusion, and curvelet fusion. In the cases of wavelet and curvelet fusion we apply as the fusion criterion the maximum frequency rule. Furthermore, the two original images, and excavations near the area suggest that the dominant orientations of the buried features are north-south and east-west. Therefore, in curvelet fusion method, in curvelet domain we enhance the image details along these specific orientations, additionally to the fusion. The resultant fused images succeed to map linear and rectangular features that were not easily visible in the original images

  14. Volume equivalente: um estudo em indivíduos com otite média crônica Equivalent volume: study in subjects with chronic otitis media

    Directory of Open Access Journals (Sweden)

    Ana P. T. Alencar

    2005-10-01

    Full Text Available O Volume Equivalente do Meato Acústico Externo está na faixa de 0,3ml a 1,0ml em crianças e 0,65ml a 1,75ml em adultos. Em indivíduos com Otite Média Crônica estes valores podem sofrer alterações, de acordo com as condições da doença. OBJETIVO: Estudar o volume equivalente de 52 orelhas de pacientes com Otite Média Crônica com e sem infecção ativa. FORMA DE ESTUDO: clínico prospectivo com coorte transversal. MATERIAL E MÉTODO: O volume equivalente da orelha foi obtido em 52 orelhas com Otite Média Crônica, com e sem infecção ativa, e num grupo controle de mesma idade e sexo do grupo estudo. O grupo estudo com infecção foi avaliado antes e após tratamento clínico. RESULTADOS: A média do volume equivalente para os grupos estudos sem e com infecção e para o grupo controle foi, respectivamente, 2,86ml; 1,42ml e 0,80ml. A média do volume equivalente para o grupo estudo com infecção antes e após tratamento clínico foi, respectivamente, 1,42ml e 1,82ml. CONCLUSÕES: 1. O Volume Equivalente médio da Orelha é maior em pacientes com Otite Média Crônica. 2. Não foi observada variação no Volume Equivalente antes e após o tratamento clínico.The equivalent ear canal volume ranges from 0.3ml to 1.0ml in children and from 0.65 to 1.75ml in adults. In subjects with chronic otitis media these values can be different, according to the disease status. AIM: To study the equivalent ear canal volume in 52 ears of patients with chronic otitis media with and without active infection. STUDY DESIGN: clinical prospective with transversal cohort. MATERIAL AND METHOD: The equivalent ear canal volume was obtained from 52 ears diagnosed with chronic otitis media with and without active infection and in age and gender matched control group. The study group with active infection was evaluated before and after clinical treatment. RESULTS: Equivalent ear canal volume mean for the studied groups with and without infection and for the

  15. Study of a passive companion microsatellite to the SAOCOM-1B satellite of Argentina, for bistatic and interferometric SAR applications

    Science.gov (United States)

    Barbier, Christian; Derauw, Dominique; Orban, Anne; Davidson, Malcolm W. J.

    2014-10-01

    We report the results of a preparatory study aimed at exploring candidate applications that could benefit from a passive micro-satellite accompanying the L-band SAOCOM-1B satellite of Argentina, and to carry out a limited demonstration, based on data acquired during ESA airborne campaigns, of selected applications. In a first step of the study, the potential applications were identified and prioritized based on the mission context and strategic applications, scientific need, and feasibility. The next step of the study was to carry out some demonstrations using data sets acquired during the BioSAR 2007-2009, TropiSAR 2009 and IceSAR 2007 campaigns. A P-band InSAR digital elevation model was generated from BioSAR 2007 data. Time-series of interferometric coherence maps were obtained as a tool for change detection and monitoring. PolInSAR processing was carried out on BioSAR 2007 and IceSAR data.

  16. Study on Cell Error Rate of a Satellite ATM System Based on CDMA

    Institute of Scientific and Technical Information of China (English)

    赵彤宇; 张乃通

    2003-01-01

    In this paper, the cell error rate (CER) of a CDMA-based satellite ATM system is analyzed. Two fading models, i.e. the partial fading model and the total fading model are presented according to multi-path propagation fading and shadow effect. Based on the total shadow model, the relation of CER vs. the number of subscribers at various elevations under 2D-RAKE receiving and non-diversity receiving is got. The impact on cell error rate with pseudo noise (PN) code length is also considered. The result that the maximum likelihood combination of multi-path signal would not improve the system performance when multiple access interference (MAI) is small, on the contrary the performance may be even worse is abtained.

  17. Study the Space Debris Impact in the Early Stages of the Nano-Satellite Design

    Science.gov (United States)

    Mahdi, Mohammed Chessab

    2016-12-01

    The probability of KufaSat collisions with different sizes of orbital debris and with other satellites which operating in the same orbit during orbital lifetime was determined. Apogee/Perigee Altitude History was used to graph apogee and perigee altitudes over KufaSat lifetime. The required change in velocity for maneuvers necessary to reentry atmospheric within 25 years was calculated. The prediction of orbital lifetime of KufaSat using orbital parameters and engineering specifications as inputs to the Debris Assessment Software (DAS) was done, it has been verified that the orbital lifetime will not be more than 25 years after end of mission which is compatible with recommendation of Inter-Agency Space Debris Coordination Committee (IADC).

  18. Satellite imaging coral reef resilience at regional scale. A case-study from Saudi Arabia.

    Science.gov (United States)

    Rowlands, Gwilym; Purkis, Sam; Riegl, Bernhard; Metsamaa, Liisa; Bruckner, Andrew; Renaud, Philip

    2012-06-01

    We propose a framework for spatially estimating a proxy for coral reef resilience using remote sensing. Data spanning large areas of coral reef habitat were obtained using the commercial QuickBird satellite, and freely available imagery (NASA, Google Earth). Principles of coral reef ecology, field observation, and remote observations, were combined to devise mapped indices. These capture important and accessible components of coral reef resilience. Indices are divided between factors known to stress corals, and factors incorporating properties of the reef landscape that resist stress or promote coral growth. The first-basis for a remote sensed resilience index (RSRI), an estimate of expected reef resilience, is proposed. Developed for the Red Sea, the framework of our analysis is flexible and with minimal adaptation, could be extended to other reef regions. We aim to stimulate discussion as to use of remote sensing to do more than simply deliver habitat maps of coral reefs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Study, optimization, and design of a laser heat engine. [for satellite applications

    Science.gov (United States)

    Taussig, R. T.; Cassady, P. E.; Zumdieck, J. F.

    1978-01-01

    Laser heat engine concepts, proposed for satellite applications, are analyzed to determine which engine concept best meets the requirements of high efficiency (50 percent or better), continuous operation in space using near-term technology. The analysis of laser heat engines includes the thermodynamic cycles, engine design, laser power sources, collector/concentrator optics, receiving windows, absorbers, working fluids, electricity generation, and heat rejection. Specific engine concepts, optimized according to thermal efficiency, are rated by their technological availability and scaling to higher powers. A near-term experimental demonstration of the laser heat engine concept appears feasible utilizing an Otto cycle powered by CO2 laser radiation coupled into the engine through a diamond window. Higher cycle temperatures, higher efficiencies, and scalability to larger sizes appear to be achievable from a laser heat engine design based on the Brayton cycle and powered by a CO laser.

  20. Feasibility study on UV/visible imaging spectrograph (Geo-OPUS) for GOAL satellite proposal

    Science.gov (United States)

    Suzuki, M.; Kita, K.; Toshimi, T.; Okumura, S.; Shiomi, K.; Imamura, T.; Nakamura, M.

    Geo-OPUS geostationary ozone and air pollution monitoring UV visible spectrometer is a core instrument of GOAL geostationary observation of atmospheric chemistry and lightning satellite proposal Geo-OPUS is an imaging spectrograph to scan earth disk 20km x 20 km nadir pixel 512 north-south pixels IFOV and whole disk FOV within 1 hour observation cycle which observes 270-450 nm with 0 3 nm spectral sampling Onboard spectral calibration 0 01 nm accuracy is carried out using Hg lamp and solar lines Radio Diffuser plates are used for radiometric calibration Primary observation targets are total column of NO2 SO2 O3 also stratospheric profile HCHO and aerosols It also measures stratospheric species OClO BrO etc High SNR and spectral calibration stability are required to derive species such as tropospheric O3 column in 10-20 accuracy required by IGOS-P IGACO

  1. Internet-Based Laboratory Activities Designed for Studying the Sun with Satellites

    Science.gov (United States)

    Slater, T. F.

    1998-12-01

    Yohkoh Public Outreach Project (YPOP) is a collaborative industry, university, and K-16 project bringing fascinating and dynamic images of the Sun to the public in real-time. Partners have developed an extensive public access and educational WWW site containing more than 100 pages of vibrant images with current information that focuses on movies of the X-ray output of our Sun taken by the Yohkoh Satellite. More than 5 Gb of images and movies are available on the WWW site from the Yohkoh satellite, a joint project of the Institute for Space and Astronautical Sciences (ISAS) and NASA. Using a movie theater motif, the site was created by teams working at Lockheed Martin Advanced Technology Center, Palo Alto, CA in the Solar and Astrophysics Research Group, the Montana State University Solar Physics Research Group, and the Montana State University Conceptual Astronomy and Physics Education Research Group with funding from the NASA Learning Technology Project (LTP) program (NASA LTP SK30G4410R). The Yohkoh Movie Theater Internet Site is found at URL: http://www.lmsal.com/YPOP/ and mirrored at URL: http://solar.physics.montana.edu/YPOP/. In addition to being able to request automated movies for any dates in a 5 Gb on-line database, the user can view automatically updated daily images and movies of our Sun over the last 72 hours. Master science teachers working with the NASA funded Yohkoh Public Outreach Project have developed nine technology-based on-line lessons for K-16 classrooms. These interdisciplinary science, mathematics, and technology lessons integrate Internet resources, real-time images of the Sun, and extensive NASA image databases. Instructors are able to freely access each of the classroom-ready activities. The activities require students to use scientific inquiry skills and manage electronic information to solve problems consistent with the emphasis of the NRC National Science Education Standards.

  2. STUDY OF POLLUTANT DISTRIBUTION IN BENOA BAY USING NUMERICAL SIMULATION AND SATELLITE DATA

    Directory of Open Access Journals (Sweden)

    Komang Ardana

    2012-11-01

    Full Text Available Euthrofication that caused by nitrate and phosphate contamination and also sedimentation process is the mainproblem that took place in Benoa Bay Territorial water. The distribution of phosphate pollutant in Benoa bay territorialwater was modeled by numeric of Princeton Ocean model (POM. The input of this pollutant model were a tidal currentpattern, M2 tidal current residue, biological factor, physic and chemistry, that influenced pollutant concentration.Meanwhile, the sedimentation concentration was mapped with ALOS AVNIR-2 sensor image satellite and this image wasanalysed with statistic method (Linear Regression.The result of phosphate modeling concentration was 0.1 mg/1 to 0.0022 mg/1, where the concentration wascategorized very hazardous to the territorial water environment. Because the phosphate concentration in a pollutantresources was beyond the standard level of environmental quality, that was 0.015 mg/1 for fishery cultivation and alsotourism activity (Bali Governor Regulation No.8th 2007. While, the direction of the distribution was affected by currentpattern of movement, that was when the ebb level of high water moving into the bay and when the ebb to high tidemoving out of the bay.The result of statistic approaches with ALOS of AVNIR-2 censor can be used for mapping sedimentationdistribution advantages in Benoa Bay. The values were: R2 Band 1 is 0.3839, Band 2 is 0.6123 and Band 3 is 0.5468. Inthis methodology, the correlation was not significant, due to, the quantity of in-situ data was small and the time researchwas not at the same time with satellite data.

  3. Soil Moisture Data Assimilation in a Hydrological Model: A Case Study in Belgium Using Large-Scale Satellite Data

    Directory of Open Access Journals (Sweden)

    Pierre Baguis

    2017-08-01

    Full Text Available In the present study, we focus on the assimilation of satellite observations for Surface Soil Moisture (SSM in a hydrological model. The satellite data are produced in the framework of the EUMETSAT project H-SAF and are based on measurements with the Advanced radar Scatterometer (ASCAT, embarked on the Meteorological Operational satellites (MetOp. The product generated with these measurements has a horizontal resolution of 25 km and represents the upper few centimeters of soil. Our approach is based on the Ensemble Kalman Filter technique (EnKF, where observation and model uncertainties are taken into account, implemented in a conceptual hydrological model. The analysis is carried out in the Demer catchment of the Scheldt River Basin in Belgium, for the period from June 2013–May 2016. In this context, two methodological advances are being proposed. First, the generation of stochastic terms, necessary for the EnKF, of bounded variables like SSM is addressed with the aid of specially-designed probability distributions, so that the bounds are never exceeded. Second, bias due to the assimilation procedure itself is removed using a post-processing technique. Subsequently, the impact of SSM assimilation on the simulated streamflow is estimated using a series of statistical measures based on the ensemble average. The differences from the control simulation are then assessed using a two-dimensional bootstrap sampling on the ensemble generated by the assimilation procedure. Our analysis shows that data assimilation combined with bias correction can improve the streamflow estimations or, at a minimum, produce results statistically indistinguishable from the control run of the hydrological model.

  4. STUDY OF TOTAL SUSPENDED MATTER TRANSPORTATION AND CIRCULATION IN JAKARTA BAY USING NUMERICAL SIMULATION AND SATELLITE DATA

    Directory of Open Access Journals (Sweden)

    Luh Made Suriwati

    2012-11-01

    Full Text Available Jakarta Bay lies in the north of Jakarta and receives freshwater run off from thirteen rivers that run through the Jakarta metropolitan area, a conurbation that is home to some 20 millions people. Total discharges of organic water pollution have experienced a rapid increase from 214 tones per day in 1980 to over 537 tones per day in 1993. This is resulted to the high nutrient levels and eutrophication of coastal waters. Input pollutant in Jakarta Bay change the natural environment condition. Eutrophication has severe local impacts in the Jakarta Bay (GEF, 2008. Study of TSM in Jakarta Bay was conducted during September 2008 to June 2009. The aims of this research were to investigate the transportations of TSM in Jakarta Bay MODIS satellite data was used and the current pattern circulation in Jakarta Bay. Methods applied were MODIS satellite data analyses from 2003 to 2005 and numerical model 2-dimensional, for the in-situ data of total suspended matter secondary data from LIPI in September 2004 was applied. To validate the result regression method was used. Validation research results using MODIS satellite analysis showed the regression coefficient is R=0.72. Vector of current in Jakarta Bay in September 2004 experienced of the change direction and speed at each condition during spring condition at flood tide 1.23 m/s, highest tide 0.77 m/s, ebb tide 0.83 m/s, and lowest tide1.31 m/s and during neap condition at flood tide 0.71 m/s, highest tide 0.69 m/s, ebb tide 0.90 m/s, and lowest tide 0.34 m/s. Transportation of TSM in Jakarta Bay are dynamic, in dry season transportation of TSM higher than rain season.

  5. Sub-basin-scale sea level budgets from satellite altimetry, Argo floats and satellite gravimetry: a case study in the North Atlantic Ocean

    Science.gov (United States)

    Kleinherenbrink, Marcel; Riva, Riccardo; Sun, Yu

    2016-11-01

    In this study, for the first time, an attempt is made to close the sea level budget on a sub-basin scale in terms of trend and amplitude of the annual cycle. We also compare the residual time series after removing the trend, the semiannual and the annual signals. To obtain errors for altimetry and Argo, full variance-covariance matrices are computed using correlation functions and their errors are fully propagated. For altimetry, we apply a geographically dependent intermission bias [Ablain et al.(2015)], which leads to differences in trends up to 0.8 mm yr-1. Since Argo float measurements are non-homogeneously spaced, steric sea levels are first objectively interpolated onto a grid before averaging. For the Gravity Recovery And Climate Experiment (GRACE), gravity fields full variance-covariance matrices are used to propagate errors and statistically filter the gravity fields. We use four different filtered gravity field solutions and determine which post-processing strategy is best for budget closure. As a reference, the standard 96 degree Dense Decorrelation Kernel-5 (DDK5)-filtered Center for Space Research (CSR) solution is used to compute the mass component (MC). A comparison is made with two anisotropic Wiener-filtered CSR solutions up to degree and order 60 and 96 and a Wiener-filtered 90 degree ITSG solution. Budgets are computed for 10 polygons in the North Atlantic Ocean, defined in a way that the error on the trend of the MC plus steric sea level remains within 1 mm yr-1. Using the anisotropic Wiener filter on CSR gravity fields expanded up to spherical harmonic degree 96, it is possible to close the sea level budget in 9 of 10 sub-basins in terms of trend. Wiener-filtered Institute of Theoretical geodesy and Satellite Geodesy (ITSG) and the standard DDK5-filtered CSR solutions also close the trend budget if a glacial isostatic adjustment (GIA) correction error of 10-20 % is applied; however, the performance of the DDK5-filtered solution strongly depends

  6. Signature of range observable in non-dynamical Chern-Simons modified gravity and the measurements with satellite-satellite tracking missions. Theoretical Studies

    CERN Document Server

    Qiang, Li-E

    2014-01-01

    Having great accuracy in the range and range rate measurements, the operating GRACE mission and the planed GRACE Follow On mission can in principle be employed to place strong constraints on certain relativistic gravity theories. In this paper, we work out in details the range observable in the non-dynamical Chern-Simons modified gravity for these Satellite-Satellite Tracking measurements. We find out that an characteristic time accumulating signal appears in the range observable in the non-dynamical Chern-Simons gravity, which has no analogy found in the standard metric theories of gravity. The magnitude of this Chern-Simons range signal will reach to a few times of $(\\frac{\\dot{\\theta}}{100r})meters$ for each free flight of these SST missions, here $\\dot{\\theta}$ measures the length scale of the theory and $r$ denotes the orbital radius of the SST mission. Therefore, with the 12 years data from the GRACE mission and the proper data analysis methods, one expects that the mass scale of the non-dynamical CS gr...

  7. Study on relationship between polymorphism of Har gene (CAG)n micro-satellite and prostate cancer

    Institute of Scientific and Technical Information of China (English)

    WANG Gang; WANG Xiao-hui; XIA Bing; CHEN Guang-chun; LU Jian

    2002-01-01

    Objective: To study the relationship between the polymorphic (CAG)n micro-satellite of human androgen receptor (bAR) gene and prostate cancer (Pca). Methods: The number of (CAG)n repeats in 107 normal males were measured by a two-step [α-32P]-dCTP incorporated asymmetric polymeric chain reaction (PCR), and the (CAG)n repeats of both malignant and nonmalignant prostate cells in fixed paraffin-embedded tissue (PET) specimen from 36 case of Pca were determined by sequence analysis. Results: The repeats of polymorphic (CAG) n among normal men ranged from 11 to 29, and the most frequent repeat was 22(18. 69%), with 23(14. 02%), 24(10. 28%) and 21(10. 28%) being less frequent. The (CAG)n repeats of malignant prostate cells equaled to that of nonmalignant adjacent prostate tissue cells from the same PET specimen in all 36 Pca, and the (CAG)n repeats in 36 Pca which ranged from 16 to 22 were shorter than that in normal males significantly (P<0. 05), while no significant difference in (CAG)n repeats among various grade of tumor's differentiation(well-differentiated, intermediate-differentiated and poor-differentiated) was found (P> 0. 05). Conclusion: The present study suggest that short hAR gene (CAG)n micro-satellite might be associated with the occurrence of Pca, but not with the differentiation of Pca.

  8. Microdischarge plasma thrusters for small satellite propulsion

    Science.gov (United States)

    Raja, Laxminarayan

    2009-10-01

    Small satellites weighing less than 100 kg are gaining importance in the defense and commercial satellite community owing to advantages of low costs to build and operate, simplicity of design, rapid integration and testing, formation flying, and multi-vehicle operations. The principal challenge in the design and development of small satellite subsystems is the severe mass, volume, and power constraints posed by the overall size of the satellite. The propulsion system in particular is hard to down scale and as such poses a major stumbling block for small satellite technology. Microdischarge-based miniaturized plasma thrusters are potentially a novel solution to this problem. In its most basic form a microdischarge plasma thruster is a simple extension of a cold gas micronozzle propulsion device, where a direct or alternating current microdischarge is used to preheat the gas stream to improve to specific impulse of the device. We study a prototypical thruster device using a detailed, self-consistent coupled plasma and fluid flow computational model. The model describes the microdischarge power deposition, plasma dynamics, gas-phase chemical kinetics, coupling of the plasma phenomena with high-speed flow, and overall propulsion system performance. Unique computational challenges associated with microdischarge modeling in the presence of high-speed flows are addressed. Compared to a cold gas micronozzle, a significant increase in specific impulse (50 to 100 %) is obtained from the power deposition in the diverging supersonic section of the thruster nozzle. The microdischarge remains mostly confined inside the micronozzle and operates in an abnormal glow discharge regime. Gas heating, primarily due to ion Joule heating, is found to have a strong influence on the overall discharge behavior. The study provides a validation of the concept as simple and effective approach to realizing a relatively high-specific impulse thruster device at small geometric scales.

  9. Multicenter Study of Brain Volume Abnormalities in Children and Adolescent-Onset Psychosis

    Science.gov (United States)

    Reig, Santiago; Parellada, Mara; Castro-Fornieles, Josefina; Janssen, Joost; Moreno, Dolores; Baeza, Inmaculada; Bargalló, Nuria; González-Pinto, Ana; Graell, Montserrat; Ortuño, Felipe; Otero, Soraya; Arango, Celso; Desco, Manuel

    2011-01-01

    The goal of the study is to determine the extent of structural brain abnormalities in a multicenter sample of children and adolescents with a recent-onset first episode of psychosis (FEP), compared with a sample of healthy controls. Total brain and lobar volumes and those of gray matter (GM), white matter, and cerebrospinal fluid (CSF) were measured in 92 patients with a FEP and in 94 controls, matched for age, gender, and years of education. Male patients (n = 64) showed several significant differences when compared with controls (n = 61). GM volume in male patients was reduced in the whole brain and in frontal and parietal lobes compared with controls. Total CSF volume and frontal, temporal, and right parietal CSF volumes were also increased in male patients. Within patients, those with a further diagnosis of “schizophrenia” or “other psychosis” showed a pattern similar to the group of all patients relative to controls. However, bipolar patients showed fewer differences relative to controls. In female patients, only the schizophrenia group showed differences relative to controls, in frontal CSF. GM deficit in male patients with a first episode correlated with negative symptoms. Our study suggests that at least part of the GM deficit in children and adolescent-onset schizophrenia and in other psychosis occurs before onset of the first positive symptoms and that, contrary to what has been shown in children-onset schizophrenia, frontal GM deficits are probably present from the first appearance of positive symptoms in children and adolescents. PMID:20478821

  10. Perfusion analysis using a wide coverage flat-panel volume CT: feasibility study

    Science.gov (United States)

    Grasruck, M.; Gupta, R.; Reichardt, B.; Klotz, E.; Schmidt, B.; Flohr, T.

    2007-03-01

    We developed a Flat-panel detector based Volume CT (VCT) prototype scanner with large z-coverage. In that prototype scanner a Varian 4030CB a-Si flat-panel detector was mounted in a multi slice CT-gantry (Siemens Medical Solutions) which provides a 25 cm field of view with 18 cm z-coverage at isocenter. The large volume covered in one rotation can be used for visualization of complete organs of small animals, e.g. rabbits. By implementing a mode with continuous scanning, we are able to reconstruct the complete volume at any point in time during the propagation of a contrast bolus. Multiple volumetric reconstructions over time elucidate the first pass dynamics of a bolus of contrast resulting in 4-D angiography and potentially allowing whole organ perfusion analysis. We studied to which extent pixel based permeability and blood volume calculation with a modified Patlak approach was possible. Experimental validation was performed by imaging evolution of contrast bolus in New Zealand rabbits. Despite the short circulation time of a rabbit, the temporal resolution was sufficient to visually resolve various phases of the first pass of the contrast bolus. Perfusion imaging required substantial spatial smoothing but allowed a qualitative discrimination of different types of parenchyma in brain and liver. If a true quantitative analysis is possible, requires further studies.

  11. Ocean Thermal Energy Conversion (OTEC) test facilities study program. Final report. Volume II. Part A

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-17

    Results are presented of an 8-month study to develop alternative non-site-specific OTEC facilities/platform requirements for an integrated OTEC Test Program which may include land and floating test facilities. The document, Volume II - Appendixes is bound in three parts (A, B, and C) which together comprise a compendium of the most significant detailed data developed during the study. Part A contains definitions, baseline revisions, test plans, and energy utilization sections.

  12. IEA Wind Task 24 Integration of Wind and Hydropower Systems; Volume 2: Participant Case Studies

    Energy Technology Data Exchange (ETDEWEB)

    Acker, T.

    2011-12-01

    This report describes the background, concepts, issues and conclusions related to the feasibility of integrating wind and hydropower, as investigated by the members of IEA Wind Task 24. It is the result of a four-year effort involving seven IEA member countries and thirteen participating organizations. The companion report, Volume 2, describes in detail the study methodologies and participant case studies, and exists as a reference for this report.

  13. A Satellite-Derived Upper-Tropospheric Water Vapor Transport Index for Climate Studies

    Science.gov (United States)

    Jedlovec, Gray J.; Lerner, Jeffrey A.; Atkinson, Robert J.

    1998-01-01

    A new approach is presented to quantify upper-level moisture transport from geostationary satellite data. Daily time sequences of Geostationary Operational Environmental Satellite GOES-7 water vapor imagery were used to produce estimates of winds and water vapor mixing ratio in the cloud-free region of the upper troposphere sensed by the 6.7- microns water vapor channel. The winds and mixing ratio values were gridded and then combined to produce a parameter called the water vapor transport index (WVTI), which represents the magnitude of the two-dimensional transport of water vapor in the upper troposphere. Daily grids of WVTI, meridional moisture transport, mixing ratio, pressure, and other associated parameters were averaged to produce monthly fields for June, July, and August (JJA) of 1987 and 1988 over the Americas and surrounding oceanic regions, The WVTI was used to compare upper-tropospheric moisture transport between the summers of 1987 and 1988, contrasting the latter part of the 1986/87 El Nino event and the La Nina period of 1988. A similar product derived from the National Centers for Environmental Prediction (NCEP)-National Center for Atmospheric Research (NCAR) 40-Year Reanalysis Project was used to help to validate the index. Although the goal of this research was to describe the formulation and utility of the WVTI, considerable insight was obtained into the interannual variability of upper-level water vapor transport. Both datasets showed large upper-level water vapor transport associated with synoptic features over the Americas and with outflow from tropical convective systems. Minimal transport occurred over tropical and subtropical high pressure regions where winds were light. Index values from NCEP-NCAR were 2-3 times larger than that determined from GOES. This difference resulted from large zonal wind differences and an apparent overestimate of upper-tropospheric moisture in the reanalysis model. A comparison of the satellite-derived monthly

  14. Lower Flathead System Fisheries Study, Executive Summary, Volume I, 1983-1987 Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Cross, David; DosSantos, Joseph M.

    1988-06-01

    This Executive Summary, Volume I, of the lower Flathead System Fisheries Study Final Report, was prepared to provide a study overview for persons who are not fisheries scientists. The contents provide an introduction to the study and its objectives, a short description of the study area, a discussion of the major findings and conclusions of the study, and the description of fisheries management alternatives available to managers of the lower Flathead system. Technical reports were prepared for those portions of the study dealing with the lower Flathead River and its tributaries, Volume II, and the South Bay of Flathead Lake, Volume III. The annual hydrographic regime of the Flathead system, consisting of upper rivers, lake and lower river, has been modified by the construction and operation of two major hydroelectric facilities, Hungry Horse Dam on the south fork Flathead River and Kerr Dam at the outlet of Flathead Lake. The modified hydrographic regime has resulted in significant impacts to kokanee (Oncorhynchus nerka) and several species of trout. Kerr Dam, closed in 1938, controls Flathead Lake levels between 878.7 m (2883 ft) and 881.8 m (2893 ft) and discharges into the lower Flathead River. Kerr Dam is a 63.4 m (208 ft) high concrete arch structure located 7.2 km (4.5 miles) downstream from the outlet of Flathead Lake. The facility is used by Montana Power Company primarily for system frequency load control with some use for low level base load. 77 refs., 5 figs.

  15. Using R for analysing spatio-temporal datasets: a satellite-based precipitation case study

    Science.gov (United States)

    Zambrano-Bigiarini, Mauricio

    2017-04-01

    Increasing computer power and the availability of remote-sensing data measuring different environmental variables has led to unprecedented opportunities for Earth sciences in recent decades. However, dealing with hundred or thousands of files, usually in different vectorial and raster formats and measured with different temporal frequencies, impose high computation challenges to take full advantage of all the available data. R is a language and environment for statistical computing and graphics which includes several functions for data manipulation, calculation and graphical display, which are particularly well suited for Earth sciences. In this work I describe how R was used to exhaustively evaluate seven state-of-the-art satellite-based rainfall estimates (SRE) products (TMPA 3B42v7, CHIRPSv2, CMORPH, PERSIANN-CDR, PERSIAN-CCS-adj, MSWEPv1.1 and PGFv3) over the complex topography and diverse climatic gradients of Chile. First, built-in functions were used to automatically download the satellite-images in different raster formats and spatial resolutions and to clip them into the Chilean spatial extent if necessary. Second, the raster package was used to read, plot, and conduct an exploratory data analysis in selected files of each SRE product, in order to detect unexpected problems (rotated spatial domains, order or variables in NetCDF files, etc). Third, raster was used along with the hydroTSM package to aggregate SRE files into different temporal scales (daily, monthly, seasonal, annual). Finally, the hydroTSM and hydroGOF packages were used to carry out a point-to-pixel comparison between precipitation time series measured at 366 stations and the corresponding grid cell of each SRE. The modified Kling-Gupta index of model performance was used to identify possible sources of systematic errors in each SRE, while five categorical indices (PC, POD, FAR, ETS, fBIAS) were used to assess the ability of each SRE to correctly identify different precipitation intensities

  16. Evolution of stratospheric ozone and water vapour time series studied with satellite measurements

    Directory of Open Access Journals (Sweden)

    A. Jones

    2009-01-01

    Full Text Available The long term evolution of stratospheric ozone and water vapour has been investigated by extending satellite time series to April 2008. For ozone, we examine monthly average ozone values from various satellite data sets for nine latitude and altitude bins covering 60° S to 60° N and 20–45 km and covering the time period 1979–2008. Data are from the Stratospheric Aerosol and Gas Experiment (SAGE I+II, the HALogen Occultation Experiment (HALOE, the Solar BackscatterUltraViolet-2 (SBUV/2 instrument, the Sub-Millimetre Radiometer (SMR, the Optical Spectrograph InfraRed Imager System (OSIRIS, and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartograpY (SCIAMACHY. Monthly ozone anomalies are calculated by utilising a linear regression model, which also models the solar, quasi-biennial oscillation (QBO, and seasonal cycle contributions. Individual instrument ozone anomalies are combined producing a weighted all instrument average. Assuming a turning point of 1997 and that the all instrument average is represented by good instrumental long term stability, the largest statistically significant ozone declines from 1979–1997 are seen at the mid-latitudes between 35 and 45 km, namely −7.7%/decade in the Northern Hemisphere and −7.8%/decade in the Southern Hemisphere. For the period 1997 to 2008 we find that the southern mid-latitudes between 35 and 45 km show the largest ozone recovery (+3.4%/decade compared to other global regions, although the estimated trend model error is of a similar magnitude (+2.1%/decade, at the 95% confidence level. An all instrument average is also constructed from water vapour anomalies during 1984–2008, using the SAGE II, HALOE, SMR, and the Microwave Limb Sounder (aura/MLS measurements. We report that the decrease in water vapour values after 2001 slows down around 2004 in the lower tropical stratosphere (20–25 km, and has even shown signs of increasing values in upper stratospheric mid

  17. Evolution of stratospheric ozone and water vapour time series studied with satellite measurements

    Directory of Open Access Journals (Sweden)

    A. Jones

    2009-08-01

    Full Text Available The long term evolution of stratospheric ozone and water vapour has been investigated by extending satellite time series to April 2008. For ozone, we examine monthly average ozone values from various satellite data sets for nine latitude and altitude bins covering 60° S to 60° N and 20–45 km and covering the time period of 1979–2008. Data are from the Stratospheric Aerosol and Gas Experiment (SAGE I+II, the HALogen Occultation Experiment (HALOE, the Solar BackscatterUltraViolet-2 (SBUV/2 instrument, the Sub-Millimetre Radiometer (SMR, the Optical Spectrograph InfraRed Imager System (OSIRIS, and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartograpY (SCIAMACHY. Monthly ozone anomalies are calculated by utilising a linear regression model, which also models the solar, quasi-biennial oscillation (QBO, and seasonal cycle contributions. Individual instrument ozone anomalies are combined producing an all instrument average. Assuming a turning point of 1997 and that the all instrument average is represented by good instrumental long term stability, the largest statistically significant ozone declines (at two sigma from 1979–1997 are seen at the mid-latitudes between 35 and 45 km, namely −7.2%±0.9%/decade in the Northern Hemisphere and −7.1%±0.9%/in the Southern Hemisphere. Furthermore, for the period 1997 to 2008 we find that the same locations show the largest ozone recovery (+1.4% and +0.8%/decade respectively compared to other global regions, although the estimated trend model errors indicate that the trend estimates are not significantly different from a zero trend at the 2 sigma level. An all instrument average is also constructed from water vapour anomalies during 1991–2008, using the SAGE II, HALOE, SMR, and the Microwave Limb Sounder (Aura/MLS measurements. We report that the decrease in water vapour values after 2001 slows down around 2004–2005 in the lower tropical stratosphere (20–25 km and has even

  18. Using Lagrangian-based process studies to test satellite algorithms of vertical carbon flux in the eastern North Pacific Ocean

    Science.gov (United States)

    Stukel, M. R.; Kahru, M.; Benitez-Nelson, C. R.; Décima, M.; Goericke, R.; Landry, M. R.; Ohman, M. D.

    2015-11-01

    The biological carbon pump is responsible for the transport of ˜5-20 Pg C yr-1 from the surface into the deep ocean but its variability is poorly understood due to an incomplete mechanistic understanding of the complex underlying planktonic processes. In fact, algorithms designed to estimate carbon export from satellite products incorporate fundamentally different assumptions about the relationships between plankton biomass, productivity, and export efficiency. To test the alternate formulations of export efficiency in remote-sensing algorithms formulated by Dunne et al. (2005), Laws et al. (2011), Henson et al. (2011), and Siegel et al. (2014), we have compiled in situ measurements (temperature, chlorophyll, primary production, phytoplankton biomass and size structure, grazing rates, net chlorophyll change, and carbon export) made during Lagrangian process studies on seven cruises in the California Current Ecosystem and Costa Rica Dome. A food-web based approach formulated by Siegel et al. (2014) performs as well or better than other empirical formulations, while simultaneously providing reasonable estimates of protozoan and mesozooplankton grazing rates. By tuning the Siegel et al. (2014) algorithm to match in situ grazing rates more accurately, we also obtain better in situ carbon export measurements. Adequate representations of food-web relationships and grazing dynamics are therefore crucial to improving the accuracy of export predictions made from satellite-derived products. Nevertheless, considerable unexplained variance in export remains and must be explored before we can reliably use remote sensing products to assess the impact of climate change on biologically mediated carbon sequestration.

  19. Object-Based Greenhouse Horticultural Crop Identification from Multi-Temporal Satellite Imagery: A Case Study in Almeria, Spain

    Directory of Open Access Journals (Sweden)

    Manuel A. Aguilar

    2015-06-01

    Full Text Available Greenhouse detection and mapping via remote sensing is a complex task, which has already been addressed in numerous studies. In this research, the innovative goal relies on the identification of greenhouse horticultural crops that were growing under plastic coverings on 30 September 2013. To this end, object-based image analysis (OBIA and a decision tree classifier (DT were applied to a set consisting of eight Landsat 8 OLI images collected from May to November 2013. Moreover, a single WorldView-2 satellite image acquired on 30 September 2013, was also used as a data source. In this approach, basic spectral information, textural features and several vegetation indices (VIs derived from Landsat 8 and WorldView-2 multi-temporal satellite data were computed on previously segmented image objects in order to identify four of the most popular autumn crops cultivated under greenhouse in Almería, Spain (i.e., tomato, pepper, cucumber and aubergine. The best classification accuracy (81.3% overall accuracy was achieved by using the full set of Landsat 8 time series. These results were considered good in the case of tomato and pepper crops, being significantly worse for cucumber and aubergine. These results were hardly improved by adding the information of the WorldView-2 image. The most important information for correct classification of different crops under greenhouses was related to the greenhouse management practices and not the spectral properties of the crops themselves.

  20. Effects of saltwater intrusion on pinewood vegetation using satellite ASTER data: the case study of Ravenna (Italy).

    Science.gov (United States)

    Barbarella, M; De Giglio, M; Greggio, N

    2015-04-01

    The San Vitale pinewood (Ravenna, Italy) is part of the remaining wooded areas within the southeastern Po Valley. Several studies demonstrated a widespread saltwater intrusion in the phreatic aquifer caused by natural and human factors in this area as the whole complex coastal system. Groundwater salinization affects soils and vegetation, which takes up water from the shallow aquifer. Changes in groundwater salinity induce variations of the leaf properties and vegetation cover, recognizable by satellite sensors as a response to different spectral bands. A procedure to identify stressed areas from satellite remote sensing data, reducing the expensive and time-consuming ground monitoring campaign, was developed. Multispectral Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data, acquired between May 2005 and August 2005, were used to calculate Normalized Difference Vegetation Index (NDVI). Within the same vegetation type (thermophilic deciduous forest), the areas with the higher vegetation index were taken as reference to identify the most stressed areas using a statistical approach. To confirm the findings, a comparison was conducted using contemporary groundwater salinity data. The results were coherent in the areas with highest and lowest average NDVI values. Instead, to better understand the behavior of the intermediate areas, other parameters influencing vegetation (meteorological data, water table depth, and tree density) were added for the interpretation of the results.

  1. Propagation of Rainfall Products uncertainties in hydrological applications : Studies in the framework of the Megha-Tropiques Satellite Mission

    Science.gov (United States)

    Gosset, M.; Roca, R.

    2012-04-01

    The use of satellite based rainfall in research or operational Hydrological application is becoming more and more frequent. This is specially true in the Tropics where ground based gages (or radar) network are generally scarce and generally degrading. The new French-Indian satellite Mission Megha-Tropiques (MT) dedicated to the water and energy budget in the tropical atmosphere will contribute to a better monitoring of rainfall in the inter-tropical zone. As part of this mission, research is developed on the use of MT rainfall products for hydrological research or operational application such as flood monitoring. A key issue for such applications is how to account for rainfall products biases and uncertainties, and how to propagate them in the end user models ? Another important question is how to chose the best space-time resolution for the rainfall forcing, given that both model performances and rain-product uncertainties are resolution dependent. This talk will present on going investigations and perspectives on this subject, with examples from the Megha_tropiques Ground validation sites. Several sensitivity studies have been carried out in the Oueme Basin in Benin, West Africa, one the instrumented basin that will be used for MT products direct and hydrological validation.

  2. Satellite observations of ethylene (C2H4) from the Aura Tropospheric Emission Spectrometer: A scoping study

    Science.gov (United States)

    Dolan, Wayana; Payne, Vivienne H.; Kualwik, Susan S.; Bowman, Kevin W.

    2016-09-01

    We present a study focusing on detection and initial quantitative estimates of ethylene (C2H4) in observations from the Tropospheric Emission Spectrometer (TES), a Fourier transform spectrometer aboard the Aura satellite that measures thermal infrared radiances with high spectral resolution (0.1 cm-1). We analyze observations taken in support of the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission and demonstrate the feasibility of future development of C2H4 into a TES standard product. In the Northern Hemisphere, C2H4 is commonly associated with boreal fire plumes, motor vehicle exhaust and petrochemical emissions. It has a short lifetime (∼14-32 h) in the troposphere due to its reaction with OH and O3. Chemical destruction of C2H4 in the atmosphere leads to the production of ozone and other species such as carbon monoxide (CO) and formaldehyde. Results indicate a correlation between C2H4 and CO in boreal fire plumes. Quantitative C2H4 estimates are sensitive to assumptions about the plume height and width. We find that C2H4 greater than 2-3 ppbv can be detected in a single TES observation (for a fire plume at 3 km altitude and 1.5 km width). Spatial averaging will be needed for surface-peaking profiles where TES sensitivity is lower.

  3. BRAIN VOLUMES OF THE LAMB, RAT AND BIRD DO NOT SHOW HEMISPHERIC ASYMMETRY: A STEREOLOGICAL STUDY

    Directory of Open Access Journals (Sweden)

    Bünyamin Sahin

    2011-05-01

    Full Text Available It is well known that there are functional differences between right and left brain hemispheres. However, it is not clear whether these functional differences are reflected in morphometric differences. This study was carried out to investigate the right-left asymmetry, and sex and species differences of the brains using the Cavalieri principle for volume estimation. Seventeen lambs, 10 rats and 12 avian brains were used to estimate brain volumes. A transparent point grid was superimposed on the slices of lamb brains directly and the slices of the rat and avian brains were projected onto a screen at 10x magnification. Surface areas of the cut slice faces were estimated by simply counting the points that hit the slices. Mean brain volumes were 37.74 cm3, 598.95 mm3 and 730.38 mm3 and the coefficients of variations were 0.08, 0.05 and 0.05 for lamb, rat and avian brains respectively. The differences between left and right hemispheres did not show statistical significance (P > 0.05. However, the male brain volumes were larger than the females for the lamb and bird (P < 0.05. In light of such findings, it will be necessary to evaluate neuron number of the brain hemispheres to provide more useful data regarding inter-hemispheric brain asymmetry.

  4. Study on the pulmonary mean transit time and the pulmonary blood volume by RI-cardiogram

    Energy Technology Data Exchange (ETDEWEB)

    Ushio, N.

    1987-03-01

    The pulmonary mean transit time and the pulmonary blood volume in cases of cardio-pulmonary disease were measured using Giuntini's method which is considered the most appropriate among radiocardiographic methods. The errors in this method were confirmed to be almost negligible. The results obtained were as follows: 1) The pulmonary mean transit time was related to the systemic mean transit time and markedly prolonged in left heart failure. On the other hand, it was markedly shortened in some cases of chronic pulmonary disease, particularly pulmonary emphysema. 2) The pulmonary blood volume tended to increase in left heart disorders and mitral valve disease and tended to decrease in the chronic pulmonary disease. The decrease was conspicuous particularly in some cases of pulmonary emphysema. 3) A structural change of the pulmonary vascular system in the chronic pulmonary disease appeared to bring about shortening of the pulmonary mean transit time and a decrease in the pulmonary blood volume. The pathophysiology of cardio-pulmonary disease can be more clarified by the RI-cardiogram used in this study, in which the pulmonary mean transit time and the pulmonary blood volume are used as the indicator.

  5. Free volumes in bulk nanocrystalline metals studied by the complementary techniques of positron annihilation and dilatometry.

    Science.gov (United States)

    Würschum, Roland; Oberdorfer, Bernd; Steyskal, Eva-Maria; Sprengel, Wolfgang; Puff, Werner; Pikart, Philip; Hugenschmidt, Christoph; Pippan, Reinhard

    2012-07-15

    Free-volume type defects, such as vacancies, vacancy-agglomerates, dislocations, and grain boundaries represent a key parameter in the properties of ultrafine-grained and nanocrystalline materials. Such free-volume type defects are introduced in high excess concentration during the processes of structural refinement by severe plastic deformation. The direct method of time-differential dilatometry is applied in the present work to determine the total amount and the kinetics of free volume by measuring the irreversible length change upon annealing of bulk nanocrystalline metals (Fe, Cu, Ni) prepared by high-pressure torsion (HPT). In the case of HPT-deformed Ni and Cu, distinct substages of the length change upon linear heating occur due to the loss of grain boundaries in the wake of crystallite growth. The data on dilatometric length change can be directly related to the fast annealing of free-volume type defects studied by in situ Doppler broadening measurements performed at the high-intensity positron beam of the FRM II (Garching, Munich, Germany).

  6. Satellite Communications for ATM

    Science.gov (United States)

    Shamma, Mohammed A.

    2003-01-01

    This presentation is an overview on Satellite Communication for the Aeronautical Telecommunication Management (ATM) research. Satellite Communications are being considered by the FAA and NASA as a possible alternative to the present and future ground systems supporting Air Traffic Communications. The international Civil Aviation Organization (ICAO) have in place Standards and Recommended Practices (SARPS) for the Aeronautical Mobile Satellite Services (AMSS) which is mainly derived from the pre-existing Inmarsat service that has been in service since the 1980s. The Working Group A of the Aeronautical Mobile Communication Panel of ICAO has also been investigating SARPS for what is called the Next Generation Satellite Service (NGSS) which conforms less to the Inmarsat based architecture and explores wider options in terms of satellite architectures. Several designs are being proposed by Firms such as Boeing, ESA, NASA that are geared toward full or secondary usage of satellite communications for ATM. Satellite communications for ATM can serve several purposes ranging from primary usage where ground services would play a minimal backup role, to an integrated solution where it will be used to cover services, or areas that are less likely to be supported by the proposed and existing ground infrastructure. Such Integrated roles can include usage of satellite communications for oceanic and remote land areas for example. It also can include relieving the capacity of the ground network by providing broadcast based services of Traffic Information Services messages (TIS-B), or Flight Information Services (FIS-B) which can take a significant portion of the ground system capacity. Additionally, satellite communication can play a backup role to support any needs for ground replacement, or additional needed capacity even after the new digital systems are in place. The additional bandwidth that can be provided via satellite communications can also open the door for many new

  7. A comparative study of spherical and flat-Earth geopotential modeling at satellite elevations

    Science.gov (United States)

    Parrott, M. H.; Hinze, W. J.; Braile, L. W.; Vonfrese, R. R. B.

    1985-01-01

    Flat-Earth modeling is a desirable alternative to the complex spherical-Earth modeling process. These methods were compared using 2 1/2 dimensional flat-earth and spherical modeling to compute gravity and scalar magnetic anomalies along profiles perpendicular to the strike of variably dimensioned rectangular prisms at altitudes of 150, 300, and 450 km. Comparison was achieved with percent error computations (spherical-flat/spherical) at critical anomaly points. At the peak gravity anomaly value, errors are less than + or - 5% for all prisms. At 1/2 and 1/10 of the peak, errors are generally less than 10% and 40% respectively, increasing to these values with longer and wider prisms at higher altitudes. For magnetics, the errors at critical anomaly points are less than -10% for all prisms, attaining these magnitudes with longer and wider prisms at higher altitudes. In general, in both gravity and magnetic modeling, errors increase greatly for prisms wider than 500 km, although gravity modeling is more sensitive than magnetic modeling to spherical-Earth effects. Preliminary modeling of both satellite gravity and magnetic anomalies using flat-Earth assumptions is justified considering the errors caused by uncertainties in isolating anomalies.

  8. A H∞/μ solution for microvibration mitigation in satellites: A case study

    Science.gov (United States)

    Preda, Valentin; Cieslak, Jérôme; Henry, David; Bennani, Samir; Falcoz, Alexandre

    2017-07-01

    The research work presented in this paper focuses on the development of a mixed active-passive microvibration mitigation solution capable of attenuating the transmitted vibrations generated by reaction wheels to a satellite structure. A representative benchmark provided by the European Space Agency (ESA) and Airbus Defence and Space, serves as a support for testing the proposed solution. The paper also covers modeling and design issues as well as a deep analysis of the solution within the H∞ / μ setting. Especially, an uncertainty modeling strategy is proposed to extract a Linear Fractional Transformation (LFT) model. Insight is naturally provided into various dynamical interactions between the plant elements such as bearing and isolator flexibility, gyroscopic effects, actuator dynamics and feedback-loop delays. The design of the mitigation solution is formulated into the H∞ / μ framework leading to a robust H∞ control strategy capable of achieving exemplary active attenuation performance across a wide range of reaction wheel speeds. A systematic analysis procedure based on the structured singular value μ is used to assess and demonstrate the robust stability and robust performance of the microvibration mitigation strategy. The proposed analysis method is also shown to be a powerful and reliable solution to identify worst-case scenarios without relying on traditional Monte Carlo campaigns. Time domain simulations based on a nonlinear high-fidelity industrial simulator are included as a validation step.

  9. Study on maintaining formations during satellite formation flying based on SDRE and LQR

    Science.gov (United States)

    Ke, Zhang; Zhenqi, He; Meibo, Lv

    2017-06-01

    Due to the influence of various perturbations of space, satellites flying in formation cannot maintain specific configurations for long durations [1,2]. In order to ensure that formation configurations are able to meet the requirements of space missions, it is important to maintain control of formation configurations. This is an urgent problem to be solved. The traditional control method for controlling formations is based on the average orbit element, and uses the assumption that the average orbit element deviation and the instantaneous orbit element deviation are approximately equal. However, the continuous control system is more difficult to achieve in engineering practice. Using a LQR (linear quadratic regulator) optimal control algorithm and SDRE (state-dependent Riccati equation) optimal control algorithm to maintain the formation flying [3,4]. Through simulation, it was found that when using the SDRE controller in the system transition process time is shorter than when the LQR controller is used, and fuel consumption is less for the SDRE controller than for the LQR controller.

  10. [Design and study of a high resolution vacuum ultraviolet imaging spectrometer carried by satellite].

    Science.gov (United States)

    Yu, Lei; Lin, Guan-yu; Qu, Yi; Wang, Shu-rong; Wang, Long-qi

    2011-12-01

    A high resolution vacuum ultraviolet imaging spectrometer prototype carried by satellite applied to the atmosphere detection of particles distribution in 115-300 nm was developed for remote sensing. First, based on the analysis of advanced loads, the optical system including an off-axis parabolic mirror as the telescope and Czerny-Turner structure as the imaging spectrometer was chosen Secondly, the 2-D photon counting detector with MCP was adopted for the characteristic that the radiation is weak in vacuum ultraviolet waveband. Then the geometric method and 1st order differential calculation were introduced to improve the disadvantages that aberrations in the traditional structure can not be corrected homogeneously to achieve perfect broadband imaging based on the aberration theory. At last, an advanced example was designed. The simulation and calculation of results demonstrate that the modulation transfer function (MTF) of total field of view is more than 0.6 in the broadband, and the spectral resolution is 1.23 nm. The structure is convenient and predominant. It proves that the design is feasible.

  11. A space-time stochastic model of rainfall for satellite remote-sensing studies

    Science.gov (United States)

    Bell, Thomas L.

    1987-01-01

    A model of the spatial and temporal distribution of rainfall is described that produces random spatial rainfall patterns with these characteristics: (1) the model is defined on a grid with each grid point representing the average rain rate over the surrounding grid box, (2) rain occurs at any one grid point, on average, a specified percentage of the time and has a lognormal probability distribution, (3) spatial correlation of the rainfall can be arbitrarily prescribed, and (4) time stepping is carried out so that large-scale features persist longer than small-scale features. Rain is generated in the model from the portion of a correlated Gaussian random field that exceeds a threshold. The portion of the field above the threshold is rescaled to have a lognormal probability distribution. Sample output of the model designed to mimic radar observations of rainfall during the Global Atmospheric Research Program Atlantic Tropical Experiment (GATE), is shown. The model is intended for use in evaluating sampling strategies for satellite remote-sensing of rainfall and for development of algorithms for converting radiant intensity received by an instrument from its field of view into rainfall amount.

  12. Ice Cloud Backscatter Study and Comparison with CALIPSO and MODIS Satellite Data

    Science.gov (United States)

    Ding, Jiachen; Yang, Ping; Holz, Robert E.; Platnick, Steven; Meyer, Kerry G.; Vaughan, Mark A.; Hu, Yongxiang; King, Michael D.

    2016-01-01

    An invariant imbedding T-matrix (II-TM) method is used to calculate the single-scattering properties of 8-column aggregate ice crystals. The II-TM based backscatter values are compared with those calculated by the improved geometric-optics method (IGOM) to refine the backscattering properties of the ice cloud radiative model used in the MODIS Collection 6 cloud optical property product. The integrated attenuated backscatter-to-cloud optical depth (IAB-ICOD) relation is derived from simulations using a CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite) lidar simulator based on a Monte Carlo radiative transfer model. By comparing the simulation results and co-located CALIPSO and MODIS (Moderate Resolution Imaging Spectroradiometer) observations, the non-uniform zonal distribution of ice clouds over ocean is characterized in terms of a mixture of smooth and rough ice particles. The percentage of the smooth particles is approximately 6 percent and 9 percent for tropical and mid-latitude ice clouds, respectively.

  13. Combined Low-Volume Polyethylene Glycol Solution Plus Stimulant Laxatives versus Standard-Volume Polyethylene Glycol Solution: A Prospective, Randomized Study of Colon Cleansing before Colonoscopy

    Directory of Open Access Journals (Sweden)

    Lawrence C Hookey

    2006-01-01

    Full Text Available INTRODUCTION: The effectiveness of polyethylene glycol solutions (PEG for colon cleansing is often limited by the inability of patients to drink adequate portions of the 4 L solution. The aim of the present study was to determine whether a reduced volume of PEG combined with stimulant laxatives would be better tolerated and as or more effective than the standard dose.

  14. OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging Studies. Exercise 5: an international multicenter reliability study using computerized MRI erosion volume measurements

    DEFF Research Database (Denmark)

    Bird, P; Ejbjerg, B; McQueen, F

    2003-01-01

    Scoring erosions on magnetic resonance imaging (MRI) is one method of estimating damage in patients with rheumatoid arthritis (RA), but it has limitations. The aim of this pilot study was to assess the feasibility and inter-reader reliability of computer assisted erosion volume estimation...... with metacarpophalangeal (MCP) joints 2 to 5 of the dominant hand included in the field of view. Three readers were instructed to grade MCP 2 and 3 using the OMERACT grading system and then to measure the erosion volume of the same joints using OSIRIS software. The inter-reader reliability of the grading method...

  15. OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging Studies. Exercise 5: an international multicenter reliability study using computerized MRI erosion volume measurements

    DEFF Research Database (Denmark)

    Bird, P; Ejbjerg, B; McQueen, F;

    2003-01-01

    Scoring erosions on magnetic resonance imaging (MRI) is one method of estimating damage in patients with rheumatoid arthritis (RA), but it has limitations. The aim of this pilot study was to assess the feasibility and inter-reader reliability of computer assisted erosion volume estimation...

  16. Citizen science land cover classification based on ground and satellite imagery: Case study Day River in Vietnam

    Science.gov (United States)

    Nguyen, Son Tung; Minkman, Ellen; Rutten, Martine

    2016-04-01

    Citizen science is being increasingly used in the context of environmental research, thus there are needs to evaluate cognitive ability of humans in classifying environmental features. With the focus on land cover, this study explores the extent to which citizen science can be applied in sensing and measuring the environment that contribute to the creation and validation of land cover data. The Day Basin in Vietnam was selected to be the study area. Different methods to examine humans' ability to classify land cover were implemented using different information sources: ground based photos - satellite images - field observation and investigation. Most of the participants were solicited from local people and/or volunteers. Results show that across methods and sources of information, there are similar patterns of agreement and disagreement on land cover classes among participants. Understanding these patterns is critical to create a solid basis for implementing human sensors in earth observation. Keywords: Land cover, classification, citizen science, Landsat 8

  17. Study of special performance and volume training loadings at swimmers in the year preparation

    Directory of Open Access Journals (Sweden)

    Balamutova N.M.

    2014-01-01

    Full Text Available Purpose : to study the dynamics of the special performance and volume of training load during annual training swimmers. Material / Methods : The study involved 14 teams of students of Kharkiv universities. All swimmers are of high qualification. Motor tests of special performance swimmers, functional tests were used to confirm the effectiveness of the training process. Results : The dynamics of special performance indicators and volume of training load of highly qualified swimmers in the annual cycle of training. Determined part of aerobic (58.3 %, aerobic- anaerobic special (34.5%, anaerobic- glycolytic (5.5%, anaerobic- alactate (1.7% loadings in the direction of total training load for the academic year. Conclusions : In preparing swimmers stayer is the most appropriate single-cycle construction of the annual cycle, and for swimmers, sprinters should be based on two-cycle version of the load distribution.

  18. From Insurgency to Stability. Volume 2: Insights from Selected Case Studies

    Science.gov (United States)

    2011-01-01

    Paul Oquist, Conflict and Politics in Colombia, New York: Academic Press, 1980; Rafael Pardo, La Historia de Las Guerras, Bogotá, 2004. 2 Known as...Verdadera Historia , Bogotá: Planeta, 2009. 58 From Insurgency to Stability, Volume II: Insights from Selected Case Studies been, or are being...1980. Pardo, Rafael, La Historia de Las Guerras, Bogotá, 2004. “Pastrana Desconoce Cómo Marchar Hacia Adelante,” El Tiempo, Bogotá, March 1, 1999. As

  19. The physics benchmark processes for the detector performance studies used in CLIC CDR Volume 3

    CERN Document Server

    Allanach, B.J.; Desch, K.; Ellis, J.; Giudice, G.; Grefe, C.; Kraml, S.; Lastovicka, T.; Linssen, L.; Marschall, J.; Martin, S.P.; Muennich, A.; Poss, S.; Roloff, P.; Simon, F.; Strube, J.; Thomson, M.; Wells, J.D.

    2012-01-01

    This note describes the detector benchmark processes used in volume 3 of the CLIC conceptual design report (CDR), which explores a staged construction and operation of the CLIC accelerator. The goal of the detector benchmark studies is to assess the performance of the CLIC ILD and CLIC SiD detector concepts for different physics processes and at a few CLIC centre-of-mass energies.

  20. A statistical study of the THEMIS satellite data for plasma sheet electrons carrying auroral upward field-aligned currents

    Science.gov (United States)

    Lee, S.; Shiokawa, K.; McFadden, J. P.

    2010-12-01

    The magnetospheric electron precipitation along the upward field-aligned currents without the potential difference causes diffuse aurora, and the magnetospheric electrons accelerated by a field-aligned potential difference cause the intense and bright type of aurora, namely discrete aurora. In this study, we are trying to find out when and where the aurora can be caused with or without electron acceleration. We statistically investigate electron density, temperature, thermal current, and conductivity in the plasma sheet using the data from the electrostatic analyzer (ESA) onboard the THEMIS-D satellite launched in 2007. According to Knight (Planet. Space Sci., 1973) and Lyons (JGR, 1980), the thermal current, jth(∝ nT^(1/2) where n is electron density and T is electron temperature in the plasma sheet), represents the upper limit to field aligned current that can be carried by magnetospheric electrons without field-aligned potential difference. The conductivity, K(∝ nT^(-1/2)), represents the efficiency of the upward field-aligned current (j) that the field-aligned potential difference (V) can produce (j=KV). Therefore, estimating jth and K in the plasma sheet is important in understanding the ability of plasma sheet electrons to carry the field-aligned current which is driven by various magnetospheric processes such as flow shear and azimuthal pressure gradient. Similar study was done by Shiokawa et al. (2000) based on the auroral electron data obtained by the DMSP satellites above the auroral oval and the AMPTE/IRM satellite in the near Earth plasma sheet at 10-18 Re on February-June 1985 and March-June 1986 during the solar minimum. The purpose of our study is to examine auroral electrons with pitch angle information inside 12 Re where Shiokawa et al. (2000) did not investigate well. For preliminary result, we found that in the dawn side inner magnetosphere (source of the region 2 current), electrons can make sufficient thermal current without field

  1. STUDY OF CORAL REEF DISTRIBUTION AROUND BADUNG STRAIT USING ALOS SATELLITE DATA

    Directory of Open Access Journals (Sweden)

    Suciati -

    2012-11-01

    Full Text Available Coral reef ecosystem has become a centre of interest because of the development of marine tourism development,coral fragment trade, and other activities that are able to destroy coral reef ecosystem. ALOS with AVNIR-2 sensor wasselected because it has 3 visible spectrums which have the ability of penetration into water column, also it have highenough of spatial resolution i.e.10 meters.The aims of this research are: 1 to identify the level of accuracy of ALOS satellite image in activity for coral reefdistribution mapping and 2 to identify the general condition of coral reefs in around Badung Strait.Preliminary processes of image processing are geometric correction and atmosphere correction. Water columneffect was reduced by Lyzenga Algorithm. Five classes were determined by multispectral classification process e.i. coral,vegetation, sand, rubble of coral and substrate. Ground check was done to identify the accuracy level. The methodaccuracy by Lillesand and Kiefer was used in this research.The result of accuracy test shows that classification accuracy was 87.16% for overall accuracy. Results of imageinterpretation show that live coral in around Badung strait is estimated to have about 141,056 hectares width. It wascovering Denpasar Regency in the east and south-east side of Serangan Island with the fringing reef type; KlungkungRegency in the west side of Lembongan Island with the fringing reef type and in the south side with the platform type,while in Gianyar Regency was not found the coral reef distribution.

  2. Crop classification using multi-temporal HJ satellite images: case study in Kashgar, Xinjiang

    Science.gov (United States)

    Hao, Pengyu; Niu, Zheng; Wang, Li

    2014-11-01

    The HJ satellite constellation, characterized as high temporal resolution (4 day revisit frequency), has high potential to obtain cloud-free images covering all cruel periods for crop classification during growing season. In this paper, three HJ images (in May, July and September) were acquired, the performances of different multi-spectral HJ CCD data combinations for crop classification in Kashgar, Xinjiang were estimated using library for Support Vector Machine (LIBSVM), and ground reference data obtained in 2011 field work were used as training and validation samples. The result showed that multi-temporal HJ data has a potential to classify crops with an overall classification accuracy of 93.77%. Among the three time periods utilized in this research, the image acquired in July achieved the highest overall accuracy (86.98%) because all summer crops were under dense canopy closure. Cotton could be accurately extracted in May image (both user and produce accuracy are above 90%) because of its lower canopy closure compared with spring, the rotate crop (wheat_maize) and winter crop (wheat) at the time period. Then, the July and September combination performed as good as that of all threetime- period combination, which indicated that images obtained at cruel time periods are enough to identify crops, and the additional images improve little on classification accuracy. In addition, multi-temporal NDVI in cruel time periods of the growing season is testified efficient to classify crops with significant phenonlogical variances since they achieved similar overall accuracy to that of multi-temporal multi-spectral combination.

  3. Satellite observations of aerosol transport from East Asia to the Arctic: three case studies

    Directory of Open Access Journals (Sweden)

    M. Di Pierro

    2010-11-01

    Full Text Available Vertical profiles of aerosols obtained with the CALIOP lidar onboard CALIPSO are used in conjunction with the GEOS-Chem chemical transport model and NOAA's HYSPLIT trajectory model to document three aerosol export events from East Asia to the Arctic that occurred in the year 2007. During each of these events CALIOP sampled the pollution plumes multiple times over periods of five to seven days. Meridional transport to the Arctic was rapid, taking 3–4 days and was accompanied by net diabatic heating of ~5 °C/day and precipitation in its ascending stage. Once in the Arctic transport was nearly isentropic with slow subsidence and radiative cooling at a rate of 1–1.5 °C/day. We find close agreement between modeled and observed plume in terms of length, altitude, thickness and, within the measurement uncertainties, extinction coefficient. In one event the satellite algorithm misclassifies the aerosol layer as ice clouds as a result of the relatively high depolarization ratio (0.06, likely caused by a somewhat high dust component in the aerosol mixture. The misclassification is more severe at daytime (67% of layers are misclassified than at nighttime (32%. The two most intense export events occurred in early spring within a three-week time span and are strongly related to a persisting blocking anticyclone that was located in the NW Pacific. Using 500 hPa geopotential height anomalies of these two events along with several others in 2007–2009 we develop a meteorological index that captures 40–60% of the variance of Asian transport events to the Arctic in winter and spring.

  4. Study of relationship between volume of distribution and body weight application to amikacin.

    Science.gov (United States)

    Rughoo, L; Bourguignon, L; Maire, P; Ducher, M

    2014-06-01

    Amikacin use is difficult because of its narrow therapeutic and its pharmacokinetic variability. This variability of amikacin is not well known. To adapt amikacin the physician assumes that there is a linear and continuous relation between the volume of distribution and the body weight. The objective of our study was to evaluate the relationship between the volume of distribution (Vd) and the body weight (BW) using a non parametric statistical analysis of dependence so called Z method. Retrospective pharmacokinetic population study and statistic analysis. 872 patients receiving intravenous amikacin. The volume of distribution was modelled using the Non Parametric Adaptive Grid algorithm (NPAG) for a two-compartment model with intravenous infusion. Z coefficient was performed to evaluate the relationships between Vd and BW. For the 872 patients (mean age of 73 ± 17 years) dispatched as follow 53 % female and 47 % male, the analysis of the statistical relationships by the non parametric Z analysis showed a scattered linkage between Vd and BW. For the whole population, the relationship between Vd and BW was not linear (regression analysis). Z analysis demonstrated that only for 80 % of patients there is a relationship between Vd and BW. For these patients, regression analysis give a significant adjustment of a linear model (r = 0.47, p < 0.001). In the whole studied population there is not a continuous and linear relationship between Vd estimated by NPAG and the BW. These results underline the difficulties to adapt doses of amikacin with only BW information.

  5. Study of Sub-basin Scale Groundwater Variations in Asia Using GRACE, Satellite Altimetry and in-situ Data

    Science.gov (United States)

    Yamamoto, K.; Fukuda, Y.; Taniguchi, M.

    2008-12-01

    A project to assess the effects of human activities on the subsurface environment in Asian developing cities is now in progress (Research Institute for Humanity and Nature., 2008). In the project, precise in situ gravity and landwater observations combined with GRACE (Gravity Recovery and Climate Experiment) satellite gravity data is proposed to evaluate local groundwater level changes of the developing urban areas in Asia. It is necessary for precise and accurate estimation of the local groundwater variations to separate local groundwater level changes from regional or global scale landwater variations. GRACE data is useful to estimate large scale landwater variations. Using GRACE Level 2 monthly gravity field solutions, we previously recovered landwater mass variation around Bangkok, in Thailand, which is one of the test areas of the project and located on the downstream of Chao Phraya river basin in the Indochina Peninsula. However, it is difficult to distinguish landwater signal of Chao Phraya river basin itself with the neighboring 3 large river basins because of the limitation of the spatial resolution of the GRACE monthly solutions. In this study, we recovered mass variation of Chao Phraya river basin using GRACE"fs along track range rate data instead of the monthly solutions. We used the method developed by Chen et al (2007), which uses GRACE"fs line-of-sight range acceleration measurements. We also tested the recoveries of landwater mass variations in other small scale river basins including Jakarta, Seoul and Taipei, which are also study areas of the project. Using the sub-basin scale landwater mass variation recovered by GRACE, we estimated groundwater level change in the project study areas by combing with in situ landwater and gravity observations. Satellite altimetry data is also used to separate groundwater variation from other landwater components as a constraint of river water storage variations.

  6. Trends in mobile satellite communication

    Science.gov (United States)

    Johannsen, Klaus G.; Bowles, Mike W.; Milliken, Samuel; Cherrette, Alan R.; Busche, Gregory C.

    1993-01-01

    Ever since the U.S. Federal Communication Commission opened the discussion on spectrum usage for personal handheld communication, the community of satellite manufacturers has been searching for an economically viable and technically feasible satellite mobile communication system. Hughes Aircraft Company and others have joined in providing proposals for such systems, ranging from low to medium to geosynchronous orbits. These proposals make it clear that the trend in mobile satellite communication is toward more sophisticated satellites with a large number of spot beams and onboard processing, providing worldwide interconnectivity. Recent Hughes studies indicate that from a cost standpoint the geosynchronous satellite (GEOS) is most economical, followed by the medium earth orbit satellite (MEOS) and then by the low earth orbit satellite (LEOS). From a system performance standpoint, this evaluation may be in reverse order, depending on how the public will react to speech delay and collision. This paper discusses the trends and various mobile satellite constellations in satellite communication under investigation. It considers the effect of orbital altitude and modulation/multiple access on the link and spacecraft design.

  7. Study on the association of green house gas (CO2) with monsoon rainfall using AIRS and TRMM satellite observations

    Science.gov (United States)

    Singh, R. B.; Janmaijaya, M.; Dhaka, S. K.; Kumar, V.

    Monsoon water cycle is the lifeline to over 60 per cent of the world's population. Throughout history, the monsoon-related calamities of droughts and floods have determined the life pattern of people. The association of Green House Gases (GHGs) particularly Carbon dioxide (CO2) with monsoon has been greatly debated amongst the scientific community in the past. The effect of CO2 on the monsoon rainfall over the Indian-Indonesian region (8-30°N, 65°-100°E) is being investigated using satellite data. The correlation coefficient (Rxy) between CO2 and monsoon is analysed. The Rxy is not significantly positive over a greater part of the study region, except a few regions. The inter-annual anomalies of CO2 is identified for playing a secondary role to influencing monsoon while other phenomenon like ENSO might be exerting a much greater influence.

  8. The application of very high resolution satellite image in urban vegetation cover investigation: a case study of Xiamen City

    Institute of Scientific and Technical Information of China (English)

    CHENGChengqi; LiBin; MATing

    2003-01-01

    With the technological improvements of satellite sensors, we will acquire more information about the earth so that we have reached a new application epoch of observation on earth environmental change and cartography. But with the enhancement of spatial resolution, some questions have arisen in the application of using traditional image processing and classification methods. Aiming for such questions, we studied the application of IKONOS very high resolution image (1 m) in Xiamen City on Urban Vegetation Cover Investigation and discussed the difference between the very high resolution image and traditional low spatial resolution image at classification,information abstraction etc. It is an advantageous test for the large-scale application of very high resolution data in the future.

  9. Seasonal distributions and migrations of Northwest Atlantic swordfish: inferences from integration of pop-up satellite archival tagging studies.

    Science.gov (United States)

    Neilson, John D; Loefer, Josh; Prince, Eric D; Royer, François; Calmettes, Beatriz; Gaspar, Philippe; Lopez, Rémy; Andrushchenko, Irene

    2014-01-01

    Data sets from three laboratories conducting studies of movements and migrations of Atlantic swordfish (Xiphias gladius) using pop-up satellite archival tags were pooled, and processed using a common methodology. From 78 available deployments, 38 were selected for detailed examination based on deployment duration. The points of deployment ranged from southern Newfoundland to the Straits of Florida. The aggregate data comprise the most comprehensive information describing migrations of swordfish in the Atlantic. Challenges in using data from different tag manufacturers are discussed. The relative utility of geolocations obtained with light is compared with results derived from temperature information for this deep-diving species. The results show that fish tagged off North America remain in the western Atlantic throughout their deployments. This is inconsistent with the model of stock structure used in assessments conducted by the International Commission for the Conservation of Atlantic Tunas, which assumes that fish mix freely throughout the North Atlantic.

  10. Secular resonances between bodies on close orbits: a case study of the Himalia prograde group of jovian irregular satellites

    CERN Document Server

    Li, Daohai

    2016-01-01

    The gravitational interaction between two objects on similar orbits can effect noticeable changes in the orbital evolution even if the ratio of their masses to that of the central body is vanishingly small. Christou (2005) observed an occasional resonant lock in the differential node $\\Delta \\Omega$ between two members in the Himalia irregular satellite group of Jupiter in the $N$-body simulations (corresponding mass ratio $\\sim 10^{-9}$). Using a semianalytical approach, we have reproduced this phenomenon. We also demonstrate the existence of two additional types of resonance, involving angle differences $\\Delta\\omega$ and $\\Delta (\\Omega+\\varpi)$ between two group members. These resonances cause secular oscillations in eccentricity and/or inclination on timescales $\\sim$ 1 Myr. We locate these resonances in $(a,e,i)$ space and analyse their topological structure. In subsequent $N$-body simulations, we confirm these three resonances and find a fourth one involving $\\Delta \\varpi$. In addition, we study the o...

  11. A numerical study of 2D detonation waves with adaptive finite volume methods on unstructured grids

    Science.gov (United States)

    Hu, Guanghui

    2017-02-01

    In this paper, a framework of adaptive finite volume solutions for the reactive Euler equations on unstructured grids is proposed. The main ingredients of the algorithm include a second order total variation diminishing Runge-Kutta method for temporal discretization, and the finite volume method with piecewise linear solution reconstruction of the conservative variables for the spatial discretization in which the least square method is employed for the reconstruction, and weighted essentially nonoscillatory strategy is used to restrain the potential numerical oscillation. To resolve the high demanding on the computational resources due to the stiffness of the system caused by the reaction term and the shock structure in the solutions, the h-adaptive method is introduced. OpenMP parallelization of the algorithm is also adopted to further improve the efficiency of the implementation. Several one and two dimensional benchmark tests on the ZND model are studied in detail, and numerical results successfully show the effectiveness of the proposed method.

  12. Simple platelet markers: Mean platelet volume and congestive heart failure coexistent with periodontal disease. Pilot studies.

    Science.gov (United States)

    Czerniuk, Maciej R; Bartoszewicz, Zbigniew; Dudzik-Niewiadomska, Iwona; Pilecki, Tomasz; Górska, Renata; Filipiak, Krzysztof J

    2017-07-17

    Conducted pilot study concerning mean platelet volume parameter among patients suffering from congestive heart failure and periodontal disease. Examination of dynamic changes of platelet and periodontal markers in group of 50 patients before and an average of 6 months subsequent to professional periodontal treatment. Both platelet and periodontal parameters decreased after periodontal treatment, what is more, the decrease of mean platelet volume (MPV) value due to periodontal disease/mm improvement was shown to be statistically significant (p = 0.05). Improvement of periodontal status may influence decrease of MPV value andincrease of congestive heart failure treatment efficacy and effect patient comfort. It is a new, not frequently used pattern of chronic disease treatment optimalization.

  13. Quantity Distortion Effect in Consumers' Perception of Different Volumes and Weights of Money: A Pilot Study.

    Science.gov (United States)

    Guido, Gianluigi; Piper, Luigi; Prete, M Irene; Mileti, Antonio; Fonda, Marco

    2016-08-01

    Consumers tend to misunderstand the physical value of cash money by adopting improper anchors for their judgments (e.g., banknote size and shape, currency denominations, etc.). In a pilot study carried out on a sample of 242 participants (n = 116 men; M age = 29.6 year, SD = 10.8), a quantity distortion effect was demonstrated by evaluating consumers' misperceptions of different monetary quantities, either in terms of volume or weight, using banknotes of the same denomination (€50). A threshold value was found, for both volume (€876,324) and weight (€371,779), above (below) which consumers tend to overrate (underrate) monetary amounts. The theoretical and operative implications are discussed.

  14. A STUDY ON SPIROMETRIC EVALUATION OF LUNG VOLUME RESTRICTION IN PREDIAGNOSED CASES OF SKELETAL FLUOROSIS

    Directory of Open Access Journals (Sweden)

    Abhijit

    2014-07-01

    Full Text Available Fluorosis is an important public health problem in India. Skeletal changes and mottled enamel may result when drinking water contains excess fluoride. Due to involvement of ribcage skeletal fluorosis causes restrictive lung disease causing reduction in vital capacity. This cross sectional observational study has been done on 55 pre diagnosed patients of skeletal fluorosis, they have been classified according to MMRC dyspnea grading & lung volume has been measured. Among 55 patients, 43 patients (78.18% have shortness of breath, it also has been seen that 13.95% patients have MMRC grade 4 dyspnea, i.e. too breathless to leave the home & 21.81% of cases have FVC < 34% of predicted, i.e. very severe lung volume restriction.

  15. Effects of yoga on arm volume among women with breast cancer related lymphedema: A pilot study.

    Science.gov (United States)

    Fisher, Mary Insana; Donahoe-Fillmore, Betsy; Leach, Laura; O'Malley, Colleen; Paeplow, Cheryl; Prescott, Tess; Merriman, Harold

    2014-10-01

    Lymphedema affects 3-58% of survivors of breast cancer and can result in upper extremity impairments. Exercise can be beneficial in managing lymphedema. Yoga practice has been minimally studied for its effects on breast cancer related lymphedema (BCRL). The purpose of this study was to determine the effect of yoga on arm volume, quality of life (QOL), self-reported arm function, and hand grip strength in women with BCRL. Six women with BCRL participated in modified Hatha yoga 3×/week for 8 weeks. Compression sleeves were worn during yoga sessions. Arm volume, QOL, self-reported arm function, and hand grip strength were measured at baseline, half-way, and at the conclusion of yoga practice. Arm volume significantly decreased from baseline (2423.3 ml ± 597.2) to final measures (2370.8 ml ± 577.2) (p = .02). No significant changes in QOL (p = .12), self-reported arm function (p = .34), or hand grip strength (p = .26) were found. Yoga may be beneficial in the management of lymphedema.

  16. VOLUME STUDY WITH HIGH DENSITY OF PARTICLES BASED ON CONTOUR AND CORRELATION IMAGE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Tatyana Yu. Nikolaeva

    2014-11-01

    Full Text Available The subject of study is the techniques of particle statistics evaluation, in particular, processing methods of particle images obtained by coherent illumination. This paper considers the problem of recognition and statistical accounting for individual images of small scattering particles in an arbitrary section of the volume in case of high concentrations. For automatic recognition of focused particles images, a special algorithm for statistical analysis based on contouring and thresholding was used. By means of the mathematical formalism of the scalar diffraction theory, coherent images of the particles formed by the optical system with high numerical aperture were simulated. Numerical testing of the method proposed for the cases of different concentrations and distributions of particles in the volume was performed. As a result, distributions of density and mass fraction of the particles were obtained, and the efficiency of the method in case of different concentrations of particles was evaluated. At high concentrations, the effect of coherent superposition of the particles from the adjacent planes strengthens, which makes it difficult to recognize images of particles using the algorithm considered in the paper. In this case, we propose to supplement the method with calculating the cross-correlation function of particle images from adjacent segments of the volume, and evaluating the ratio between the height of the correlation peak and the height of the function pedestal in the case of different distribution characters. The method of statistical accounting of particles considered in this paper is of practical importance in the study of volume with particles of different nature, for example, in problems of biology and oceanography. Effective work in the regime of high concentrations expands the limits of applicability of these methods for practically important cases and helps to optimize determination time of the distribution character and

  17. Potential for a biogenic influence on cloud microphysics over the ocean: a correlation study with satellite-derived data

    Directory of Open Access Journals (Sweden)

    A. Lana

    2012-09-01

    Full Text Available Aerosols have a large potential to influence climate through their effects on the microphysics and optical properties of clouds and, hence, on the Earth's radiation budget. Aerosol–cloud interactions have been intensively studied in polluted air, but the possibility that the marine biosphere plays an important role in regulating cloud brightness in the pristine oceanic atmosphere remains largely unexplored. We used 9 yr of global satellite data and ocean climatologies to derive parameterizations of the temporal variability of (a production fluxes of sulfur aerosols formed by the oxidation of the biogenic gas dimethylsulfide emitted from the sea surface; (b production fluxes of secondary organic aerosols from biogenic organic volatiles; (c emission fluxes of biogenic primary organic aerosols ejected by wind action on sea surface; and (d emission fluxes of sea salt also lifted by the wind upon bubble bursting. Series of global monthly estimates of these fluxes were correlated to series of potential cloud condensation nuclei (CCN numbers derived from satellite (MODIS. More detailed comparisons among weekly series of estimated fluxes and satellite-derived cloud droplet effective radius (re data were conducted at locations spread among polluted and clean regions of the oceanic atmosphere. The outcome of the statistical analysis was that positive correlation to CCN numbers and negative correlation to re were common at mid and high latitude for sulfur and organic secondary aerosols, indicating both might be important in seeding cloud droplet activation. Conversely, primary aerosols (organic and sea salt showed widespread positive correlations to CCN only at low latitudes. Correlations to re were more variable, non-significant or positive, suggesting that, despite contributing to large shares of the marine aerosol mass, primary aerosols are not widespread major drivers of the variability of cloud

  18. Parameterizing atmosphere-land surface exchange for climate models with satellite data: A case study for the Southern Great Plains CART site

    Science.gov (United States)

    Gao, W.

    High-resolution satellite data provide detailed, quantitative descriptions of land surface characteristics over large areas so that objective scale linkage becomes feasible. With the aid of satellite data, researchers examined the linearity of processes scaled up from 30 m to 15 km. If the phenomenon is scale invariant, then the aggregated value of a function or flux is equivalent to the function computed from aggregated values of controlling variables. The linear relation may be realistic for limited land areas having no large surface contrasts to cause significant horizontal exchange. However, for areas with sharp surface contrasts, horizontal exchange and different dynamics in the atmospheric boundary may induce nonlinear interactions, such as at interfaces of land-water, forest-farm land, and irrigated crops-desert steppe. The linear approach, however, represents the simplest scenario and is useful for developing an effective scheme for incorporating subgrid land surface processes into large-scale models. Our studies focus on coupling satellite data and ground measurements with a satellite-data-driven land surface model to parameterize surface fluxes for large-scale climate models. In this case study, we used surface spectral reflectance data from satellite remote sensing to characterize spatial and temporal changes in vegetation and associated surface parameters in an area of about 350 x 400 km covering the southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site of the US Department of Energy's Atmospheric Radiation Measurement (ARM) Program.

  19. Declassified intelligence satellite photographs

    Science.gov (United States)

    ,

    1998-01-01

    Recently declassified photographs from spy satellites are an important addition to the record of the Earth?s land surface held by the U.S. Geological Survey (USGS). More than 800,000 high-resolution photos taken between 1959 through 1972 were made available by Executive Order of the President. The collection is held at the USGS EROS Data Center, near Sioux Falls, S. Dak., and are offered for public sale. For some purposes in earth science studies, these photos extend the record of changes in the land surface another decade back in time from the advent of the Landsat earth-observing satellite program.

  20. A STUDY OF MEAN PLATELET VOLUME LEVELS IN PATIENTS WITH ISCHEMIC STROKE

    Directory of Open Access Journals (Sweden)

    Kandan Muralidharan

    2016-09-01

    Full Text Available CONTEXT Stroke is the most common cause of death after cardiac disease and cancer. This study attempts to identify the significance of mean platelet volume as a risk factor as well as prognostic factor for ischemic stroke patients1 . This may help in early identification of high risk individuals who can be targeted for aggressive acute management and improved secondary prevention measures. AIM OF THE STUDY To assess whether mean platelet volume levels are elevated in ischemic stroke and to assess MPV as independent risk factor and to assess whether the severity and outcome of ischemic stroke correlates with elevated mean platelet volume. SETTINGS AND DESIGN Analytical Case Control Study. MATERIALS AND METHODS This study is conducted among 50 ischemic stroke patients who were admitted at Government Rajaji Hospital, Madurai from December 2014 to June 2015. After taking detailed history and physical examination and investigations, MPV was determined for Ischemic stroke patients and Modified Rankin scale (MRS at the time of admission was calculated. After 8 weeks of onset of stroke, all the patients were again followed up. Functional outcomes were determined by use of Modified Rankin Scale (MRS2,3. All patients were stratified using MRS2,3 Scale [0-2, 3-4 and 5-6] into three groups. MPV level was correlated with MRS score at the time of admission and again at 8 weeks. Patients with MRS score of 5 and 6 were declared as very poor outcome & MRS of 3 and 4 as poor outcome. Patients with MRS 0, and 1 were considered as good outcome. STATISTICAL ANALYSIS One way ANOVA, Pearson correlation and Chi square test. RESULTS There is no statistically significant difference among the case and control groups with regard to the age or sex composition or smoking or alcoholism. MPV did not vary with diabetes or hypertension. There was a linear relation with MPV and severity of ischemic stroke i.e. as the MPV increases the severity (MRS 2,3of stroke increases

  1. A Nano-satellite Mission to Study Charged Particle Precipitation from the Van Allen Radiation Belts caused due to Seismo-Electromagnetic Emissions

    CERN Document Server

    Sivadas, Nithin; Kannapan, Deepti; Yalamarthy, Ananth Saran; Dhiman, Ankit; Bhagoji, Arjun; Shankar, Athreya; Prasad, Nitin; Ramachandran, Harishankar; Koilpillai, R David

    2014-01-01

    In the past decade, several attempts have been made to study the effects of seismo-electromagnetic emissions - an earthquake precursor, on the ionosphere and the radiation belts. The IIT Madras nano-satellite (IITMSAT) mission is designed to make sensitive measurements of charged particle fluxes in a Low Earth Orbit to study the nature of charged particle precipitation from the Van Allen radiation belts caused due to such emissions. With the Space-based Proton Electron Energy Detector on-board a single nano-satellite, the mission will attempt to gather statistically significant data to verify possible correlations with seismo-electromagnetic emissions before major earthquakes.

  2. Preventing Cancer in the Workplace and Community. Volume II. Cancer, the Worker and the Community. An Independent Study Guide.

    Science.gov (United States)

    Li, Virginia C., Ed.; And Others

    This second volume of a two-volume set on prevention of cancer in the workplace is a self-instructional manual designed for independent study by students who consult on a regular basis with an instructor. The manual follows a consistent format. The narrative text in each of three sections presents current knowledge about the subject and refers to…

  3. Secondary radiation damage as the main cause for unexpected volume effects : A histopathologic study of the parotid gland

    NARCIS (Netherlands)

    Konings, AWT; Faber, H; Cotteleer, F; Vissink, A; Coppes, RP

    2006-01-01

    Purpose: To elucidate with a histopathological study the mechanism of region-dependent volume effects in the partly irradiated parotid gland of the rat. Methods and Materials: Wistar rats were locally X-irradiated with collimators with conformal radiation portals for 100% volume and 50% cranial/caud

  4. Regenerating the Philosophy of Education: What Happened to Soul? Counterpoints: Studies in the Postmodern Theory of Education, Volume 352

    Science.gov (United States)

    Kincheloe, Joe L., Ed.; Hewitt, Randall, Ed.

    2011-01-01

    In this volume, Joe L. Kincheloe and Randall Hewitt have gathered an impressive and scholarly group of authors who argue for the continuing importance of the philosophy of education. Reviving the notion that philosophy is an essential foundation in the study and research of education, contributors to this volume directly confront the evisceration…

  5. A Simple Mercury-Free Laboratory Apparatus to Study the Relationship between Pressure, Volume, and Temperature in a Gas

    Science.gov (United States)

    McGregor, Donna; Sweeney, William V.; Mills, Pamela

    2012-01-01

    A simple and inexpensive mercury-free apparatus to measure the change in volume of a gas as a function of pressure at different temperatures is described. The apparatus is simpler than many found in the literature and can be used to study variations in pressure, volume, and temperature. (Contains 1 table and 7 figures.)

  6. Regenerating the Philosophy of Education: What Happened to Soul? Counterpoints: Studies in the Postmodern Theory of Education, Volume 352

    Science.gov (United States)

    Kincheloe, Joe L., Ed.; Hewitt, Randall, Ed.

    2011-01-01

    In this volume, Joe L. Kincheloe and Randall Hewitt have gathered an impressive and scholarly group of authors who argue for the continuing importance of the philosophy of education. Reviving the notion that philosophy is an essential foundation in the study and research of education, contributors to this volume directly confront the evisceration…

  7. A Simple Mercury-Free Laboratory Apparatus to Study the Relationship between Pressure, Volume, and Temperature in a Gas

    Science.gov (United States)

    McGregor, Donna; Sweeney, William V.; Mills, Pamela

    2012-01-01

    A simple and inexpensive mercury-free apparatus to measure the change in volume of a gas as a function of pressure at different temperatures is described. The apparatus is simpler than many found in the literature and can be used to study variations in pressure, volume, and temperature. (Contains 1 table and 7 figures.)

  8. Atrial and ventricular volume and function in persistent and permanent atrial fibrillation, a magnetic resonance imaging study

    DEFF Research Database (Denmark)

    Therkelsen, Susette Krohn; Groenning, Bjoern Aaris; Svendsen, Jesper Hastrup;

    2005-01-01

    . Intraobserver variability and inter-study reproducibility of the cardiac volumes and ejection fractions (EF) gave acceptable Bland-Altman plots, good correlations (R2: 0.80-0.99), and low reproducibility coefficients. The mean atrial volumes were similar in the two groups with AF [systolic vol. index (SVI): 75...

  9. The history of NATO TNF policy: The role of studies, analysis and exercises conference proceedings. Volume 1, Introduction and summary

    Energy Technology Data Exchange (ETDEWEB)

    Rinne, R.L. [ed.

    1994-02-01

    This conference was organized to study and analyze the role of simulation, analysis, modeling, and exercises in the history of NATO policy. The premise was not that the results of past studies will apply to future policy, but rather that understanding what influenced the decision process -- and how -- would be of value. The structure of the conference was built around discussion panels. The panels were augmented by a series of papers and presentations focusing on particular TNF events, issues, studies or exercise. The conference proceedings consist of three volumes. This volume, Volume 1, contains the conference introduction, agenda, biographical sketches of principal participants, and analytical summary of the presentations and discussion panels. Volume 2 contains a short introduction and the papers and presentations from the conference. Volume 3 contains selected papers by Brig. Gen. Robert C. Richardson III (Ret.).

  10. The history of NATO TNF policy: The role of studies, analysis and exercises conference proceedings. Volume 2: Papers and presentations

    Energy Technology Data Exchange (ETDEWEB)

    Rinne, R.L.

    1994-02-01

    This conference was organized to study and analyze the role of simulation, analysis, modeling, and exercises in the history of NATO policy. The premise was not that the results of past studies will apply to future policy, but rather that understanding what influenced the decision process -- and how -- would be of value. The structure of the conference was built around discussion panels. The panels were augmented by a series of papers and presentations focusing on particular TNF events, issues, studies, or exercises. The conference proceedings consist of three volumes. Volume 1 contains the conference introduction, agenda, biographical sketches of principal participants, and analytical summary of the presentations and panels. This volume contains a short introduction and the papers and presentations from the conference. Volume 3 contains selected papers by Brig. Gen. Robert C. Richardson III (Ret.). Individual papers in this volume were abstracted and indexed for the database.

  11. Study on magnetic field mapping within cylindrical center volume of general magnet

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Li; Lee, Sang Jin [Uiduk University, Gyeongju (Korea, Republic of)

    2016-06-15

    For the magnetic field analysis or design, it is important to know the behavior of the magnetic field in an interesting space. Magnetic field mapping becomes a useful tool for the study of magnetic field. In this paper, a numerical way for mapping the magnetic field within the cylindrical center volume of magnet is presented, based on the solution of the Laplace's equation in the cylindrical coordinate system. The expression of the magnetic field can be obtained by the magnetic flux density, which measured in the mapped volume. According to the form of the expression, the measurement points are arranged with the parallel cylindrical line (PCL) method. As example, the magnetic flux density generated by an electron cyclotron resonance ion source (ECRIS) magnet and a quadrupole magnet were mapped using the PCL method, respectively. The mapping results show the PCL arrangement method is feasible and convenience to map the magnetic field within a cylindrical center volume generated by the general magnet.

  12. Internal Kinematics of the Volume-Reduced Tongue: A Longitudinal Microsonometric Study.

    Science.gov (United States)

    Chen, Jie; Shcherbatyy, Volodymyr; Liu, Zi-Jun

    2016-01-01

    This study examined tongue internal kinematics during feeding over time after its volume reduction. Six ultrasonic crystals were implanted into the tongue to record distance changes in anterior width (AW), bilateral lengths (LENG), posterior thicknesses (THICK), and posterior dorsal (PDW) and ventral (PVW) widths in five sibling pairs of Yucatan minipigs (N = 10). In each pair, one received tongue volume reduction surgery (reduction), and the other had the identical incisions without tissue removal (sham). Functional deformation of the tongue from preimplanted ultrasonic crystals was recorded during natural feeding 1 day before, 7-8, 13-15, and 28-30 days after the surgery. The results revealed that feeding behavior and tongue functional deformation were unchanged over time in the sham pigs. However, at Days 7-8, more frequent and longer ingestion episodes were seen in the reduction as compared with the sham. Moreover, deformational changes in AW and LENG decreased, whereas those in THICK, PDW, and PVW increased significantly (P  0.05), PDW (P  0.05). These results suggest that the tongue volume reduction has significant and persistent impacts on feeding behaviors and tongue internal kinematics, and the restoring capacity of internal kinematics in the anterior tongue is limited and incomplete over time.

  13. Hydrogen bonding interactions between ethylene glycol and water: density, excess molar volume, and spectral study

    Institute of Scientific and Technical Information of China (English)

    ZHANG JianBin; ZHANG PengYan; MA Kai; HAN Fang; CHEN GuoHua; WEI XiongHui

    2008-01-01

    Studies of the density and the excess molar volume of ethylene glycol (EG)-water mixtures were carried out to illustrate the hydrogen bonding interactions of EG with water at different temperatures, The re-sults suggest that a likely complex of 3 ethylene glycol molecules bonding with 4 water molecules in an ethylene glycol-water mixture (EGW) is formed at the maximal excess molar volume, which displays stronger absorption capabilities for SO2 when the concentration of SO2 reaches 400×106 (volume ratio) in the gas phase. Meanwhile, FTIR and UV spectra of EGWs were recorded at various EG concentra-tions to display the hydrogen bonding interactions of EG with water. The FTIR spectra show that the stretching vibrational band of hydroxyl in the EGWs shifts to a lower frequency and the bending vibra-tional band of water shifts to a higher frequency with increasing the EG concentration, respectively. Furthermore, the UV spectra show that the electron transferring band of the hydroxyl oxygen in EG shows red shift with increasing the EG concentration. The frequency shifts in FTIR spectra and the shifts of absorption bands in UV absorption spectra of EGWs are interpreted as the strong hydrogen bonding interactions of the hydrogen atoms in water with the hydroxyl oxygen atoms of EG.

  14. Hippocampal volume and sensitivity to maternal aggressive behavior: a prospective study of adolescent depressive symptoms.

    Science.gov (United States)

    Whittle, Sarah; Yap, Marie B H; Sheeber, Lisa; Dudgeon, Paul; Yücel, Murat; Pantelis, Christos; Simmons, Julian G; Allen, Nicholas B

    2011-02-01

    It has been suggested that biological factors confer increased sensitivity to environmental influences on depressive symptoms during adolescence, a crucial time for the onset of depressive disorders. Given the critical role of the hippocampus in sensitivity to stress and processing of contextual aspects of the environment, investigation of its role in determining sensitivity to environmental context seems warranted. This study prospectively examined hippocampal volume as a measure of sensitivity to the influence of aggressive maternal behavior on change in depressive symptoms from early to midadolescence. The interaction between aggressive maternal behavior and hippocampal volume was found to predict change in depressive symptoms. Significant sex differences also emerged, whereby only for girls were larger bilateral hippocampal volumes more sensitive to the effects of maternal aggressive behavior, particularly with respect to experiencing the protective effects of low levels of maternal aggressiveness. These findings help elucidate the complex relationships between brain structure, environmental factors such as maternal parenting style, and sensitivity to (i.e., risk for, and protection from) the emergence of depression during this life stage. Given that family context risk factors are modifiable, our findings suggest the potential utility of targeted parenting interventions for the prevention and treatment of adolescent depressive disorder.

  15. Satellites for Commonwealth Education: Some Policy Issues. Case Studies: AUSSAT, Australia; Knowledge Network, Canada; INSAT, India; University of the South Pacific; University of the West Indies.

    Science.gov (United States)

    Bates, A. W.

    This report presents case studies on the use of satellites for education in five Commonwealth countries: Australia, Canada, India, Fiji, and Jamaica. Information provided in each of the case studies includes geography, production, the distribution system, regulation and management, and costs. Additional information given for the Australian…

  16. Study of the free volume fraction in polylactic acid (PLA) by thermal analysis

    Science.gov (United States)

    Abdallah, A.; Benrekaa, N.

    2015-10-01

    The poly (lactic acid) or polylactide (PLA) is a biodegradable polymer with high modulus, strength and thermoplastic properties. In this work, the evolution of various properties of PLA is studied, such as glass transition temperature, mechanical modules and elongation percentage with the aim of investigating the free volume fraction. To do so, two thermal techniques have been used: the dynamic mechanical analysis (DMA) and dilatometry. The results obtained by these techniques are combined to go back to the structural properties of the studied material.

  17. Remedial investigation/feasibility study of the Clinch River/Poplar Creek operable unit. Volume 5

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This volume is in support of the findings of an investigation into contamination of the Clinch River and Poplar Creek near the Oak Ridge Reservation (for more than 50 years, various hazardous and radioactive substances have been released to the environment as a result of operations and waste management activities there). It addresses the quality assurance objectives for measuring the data, presents selected historical data, contains data from several discrete water characterization studies, provides data supporting the sediment characterization, and contains data related to several biota characterization studies.

  18. Economic Radioisotope Thermoelectric Generator (RTG) study. Volume I. ERTG design. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1973-12-01

    The objectives of this study were: (1) to develop and evaluate an ERTG design for a high power, Curium-244 fueled system based on the tubular thermoelectric module technology; (2) to prepare a program plan for the development of a flight qualified ERTG; and (3) to estimate the costs associated with the production of one, ten and twenty flight qualified ERTG's. This volume presents the Reference Design ERTG approach, the results of the engineering trade studies leading to its selection, and the Second Generation ERTG Design proposed for development. (WHK)

  19. Satellite rainfall retrieval by logistic regression

    Science.gov (United States)

    Chiu, Long S.

    1986-01-01

    The potential use of logistic regression in rainfall estimation from satellite measurements is investigated. Satellite measurements provide covariate information in terms of radiances from different remote sensors.The logistic regression technique can effectively accommodate many covariates and test their significance in the estimation. The outcome from the logistical model is the probability that the rainrate of a satellite pixel is above a certain threshold. By varying the thresholds, a rainrate histogram can be obtained, from which the mean and the variant can be estimated. A logistical model is developed and applied to rainfall data collected during GATE, using as covariates the fractional rain area and a radiance measurement which is deduced from a microwave temperature-rainrate relation. It is demonstrated that the fractional rain area is an important covariate in the model, consistent with the use of the so-called Area Time Integral in estimating total rain volume in other studies. To calibrate the logistical model, simulated rain fields generated by rainfield models with prescribed parameters are needed. A stringent test of the logistical model is its ability to recover the prescribed parameters of simulated rain fields. A rain field simulation model which preserves the fractional rain area and lognormality of rainrates as found in GATE is developed. A stochastic regression model of branching and immigration whose solutions are lognormally distributed in some asymptotic limits has also been developed.

  20. Assessment of LWR spent fuel disposal options. Volume 3. Study bases and system design considerations (Appendices). Technical report

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    Volume 3 (Appendices) provides a tabulation of the bases and assumptions used in the study as well as preconceptual design description and cost estimates of the facilities and transportation systems necessary to implement the various study cases.