Science.gov

Sample records for accurate topographic maps

  1. Irrigation on Topographic Maps.

    ERIC Educational Resources Information Center

    Raitz, Karl B.

    1979-01-01

    Describes how study of irrigation practices on topographic maps can help students in introductory high school and college geography courses understand man and land relationships to geography. (Author/DB)

  2. Making Accurate Topographic Maps of the Schoolyard Using Ideas and Techniques Learned and Adapted from Multi-beam Sonar Mapping of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Fuerst, S. I.; Roberts, J. D.

    2010-12-01

    Having participated in a University of Rhode Island Project Armada expedition to join the University of New Hampshire Center for Coastal and Oceanographic Studies in making multi-beam sonar contour maps of the Arctic Ocean floor, I was able to bring the principles learned from this trip to my earth science high school students and create a project in our "mapping the earth" unit. Students learn basic surveying techniques and create authentic, accurately detailed topographic maps of the schoolyard. Models of their maps are then constructed of either Styrofoam or wood which enables them to make the transition from a 2-dimensional map to a 3-dimensional representation. Even though our maps are created using sticks, line levels, compasses and GPS, the scientific concepts of using location and elevation data to draw contour lines are identical to those used in underwater mapping. Once the students understand the science in mapping and creating contour maps to scale on graph paper by hand, they are able to easily relate this knowledge to what I was doing onboard ship using multi-beam sonar and computer mapping programs. We would like to share with you the lab and techniques that we have developed to make this activity possible with minimal materials and simple technology. As a background extension, it is also possible to replicate sonar measurements using an aquarium, food coloring, and a surface grid to map the topography of a teacher created landscape on the aquarium bottom. Earth Science students using simple tools to accurately map the topography of the school grounds

  3. MOLA TOPOGRAPHIC MAP

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The context image shows the latest MOLA topographic map of Mars' from latitude 55o S to the south pole. Values of elevation on the color scale are in meters. The along-track resolution of MOLA profiles is 330 m. Vertical precision of individual elevations approaches 37 cm. Absolute accuracy of the grid with respect to Mars' center of mass is <10 m. Note that there is a gap in data within 2.8o of the south pole due to the inclination of the MGS orbit. This gap will be filled in later this month by tilting the MGS spacecraft to an off-nadir ranging configuration. The MPL landing site region is between latitudes 72o and 78o S and longitudes 130o to 190o E.

  4. Maximum likelihood topographic map formation.

    PubMed

    Van Hulle, Marc M

    2005-03-01

    We introduce a new unsupervised learning algorithm for kernel-based topographic map formation of heteroscedastic gaussian mixtures that allows for a unified account of distortion error (vector quantization), log-likelihood, and Kullback-Leibler divergence. PMID:15802004

  5. Topographic Maps and Coal Mining.

    ERIC Educational Resources Information Center

    Raitz, Karl B.

    1984-01-01

    Geography teachers can illustrate the patterns associated with mineral fuel production, especially coal, by using United States Geological Survey topographic maps, which are illustrated by symbols that indicate mine-related features, such as shafts and tailings. Map reading exercises are presented; an interpretative map key that can facilitate…

  6. Topographic Map and Compass Use. Student Manual.

    ERIC Educational Resources Information Center

    Taylor, Michael

    This student manual is designed to introduce students to topographic maps and compass use. The first of five units included in the manual is an introduction to topographic maps. Among the topics discussed in this unit are uses, sources, and care and maintenance of topographic maps. Unit 2 discusses topographic map symbols and colors and provides a…

  7. Topographic mapping of the moon

    NASA Astrophysics Data System (ADS)

    Wu, S. S. C.

    1985-04-01

    Contour maps of the moon have been compiled by photogrammetric methods that use stereoscopic combinations of all available metric photographs from the Apollo 15, 16, and 17 missions. The maps utilize the same format as the existing NASA shaded-relief Lunar Planning Charts (LOC-1, -2, -3, and -4), which have a scale of 1:2,750,000. The map contour interval is 500 m. A control net derived from Apollo photographs by Doyle and others was used for the compilation. Contour lines and elevations are referred to the new topographic datum of the moon, which is defined in terms of spherical harmonics from the lunar gravity field. Compilation of all four LOC charts was completed on analytical plotters from 566 stereo models of Apollo metric photographs that cover approximately 20 percent of the moon. This is the first step toward compiling a global topographic map of the moon at a scale of 1:5,000,000.

  8. Elevate Your Students with Topographic Maps.

    ERIC Educational Resources Information Center

    Voltmer, Rita K.; Paulson, Robert L.

    1983-01-01

    Instructions for constructing contour models from topographic maps are presented. Includes materials needed, sources of topographic maps, tips for drawing lines, and preparing the model using cardboard. Indicates that the model is a valuable instructional tool for turning topographic maps into "real" contours of land. (Author/JN)

  9. Topographic mapping of the Moon

    USGS Publications Warehouse

    Wu, S.S.C.

    1985-01-01

    Contour maps of the Moon have been compiled by photogrammetric methods that use stereoscopic combinations of all available metric photographs from the Apollo 15, 16, and 17 missions. The maps utilize the same format as the existing NASA shaded-relief Lunar Planning Charts (LOC-1, -2, -3, and -4), which have a scale of 1:2 750 000. The map contour interval is 500m. A control net derived from Apollo photographs by Doyle and others was used for the compilation. Contour lines and elevations are referred to the new topographic datum of the Moon, which is defined in terms of spherical harmonics from the lunar gravity field. Compilation of all four LOC charts was completed on analytical plotters from 566 stereo models of Apollo metric photographs that cover approximately 20% of the Moon. This is the first step toward compiling a global topographic map of the Moon at a scale of 1:5 000 000. ?? 1985 D. Reidel Publishing Company.

  10. Topographic maps of multisensory attention.

    PubMed

    Anderson, Jeffrey S; Ferguson, Michael A; Lopez-Larson, Melissa; Yurgelun-Todd, Deborah

    2010-11-16

    The intraparietal sulcus (IPS) region is uniquely situated at the intersection of visual, somatosensory, and auditory association cortices, ideally located for processing of multisensory attention. We examined the internal architecture of the IPS region and its connectivity to other regions in the dorsal attention and cinguloinsular networks using maximal connectivity clustering. We show with resting state fMRI data from 58 healthy adolescent and young adult volunteers that points of maximal connectivity between the IPS and other regions in the dorsal attention and cinguloinsular networks are topographically organized, with at least seven maps of the IPS region in each hemisphere. Distinct clusters of the IPS exhibited differential connectivity to auditory, visual, somatosensory, and default mode networks, suggesting local specialization within the IPS region for different sensory modalities. In an independent task activation paradigm with 16 subjects, attention to different sensory modalities showed similar functional specialization within the left intraparietal sulcus region. The default mode network, in contrast, did not show a topographical relationship between regions in the network, but rather maximal connectivity in each region to a single central cluster of the other regions. The topographical architecture of multisensory attention may represent a mechanism for specificity in top-down control of attention from dorsolateral prefrontal and lateral orbitofrontal cortex and may represent an organizational unit for multisensory representations in the brain. PMID:21041658

  11. Airborne laser topographic mapping results

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.; Collins, J. G.; Link, L. E.; Swift, R. N.; Butler, M. L.

    1984-01-01

    The results of terrain mapping experiments utilizing the National Aeronautics and Space Administration (NASA) Airborne Oceanographic Lidar (AOL) over forested areas are presented. The flight tests were conducted as part of a joint NASA/U.S. Army Corps of Engineers (CE) investigation aimed at evaluating the potential of an airborne laser ranging system to provide cross-sectional topographic data on flood plains that are difficult and expensive to survey using conventional techniques. The data described in this paper were obtained in the Wolf River Basin located near Memphis, TN. Results from surveys conducted under winter 'leaves off' and summer 'leaves on' conditions, aspects of day and night operation, and data obtained from decidous and coniferous tree types are compared. Data processing techniques are reviewed. Conclusions relative to accuracy and present limitations of the AOL, and airborne lidar systems in general, to terrain mapping over forested areas are discussed.

  12. The National Map: Topographic Maps for the 21st Century

    USGS Publications Warehouse

    U.S. Geological Survey

    2006-01-01

    The U.S. Geological Survey (USGS) is committed to meeting the Nation's needs for current base geographic data and maps. Our vision is that, by working with partners, we will provide the Nation with access to current, accurate, and nationally consistent digital data and topographic maps derived from those data. This synthesis of information, products, and capabilities, The National Map, will be a seamless, continuously maintained set of geographic base information that will serve as a foundation for integrating, sharing, and using other data easily and consistently.

  13. The National Map: Topographic Maps for the 21st Century

    USGS Publications Warehouse

    U.S. Geological Survey

    2001-01-01

    The U.S. Geological Survey (USGS) is committed to meeting the Nation's needs for current base geographic data and maps. Our vision is that, by working with partners, we will provide the Nation with access to current, accurate, and nationally consistent digital data and topographic maps derived from those data. This synthesis of information, products, and capabilities, The National Map, will be a seamless, continuously maintained set of geographic base information that will serve as a foundation for integrating, sharing, and using other data easily and consistently.

  14. The National Map: Topographic Maps for the 21st Century

    USGS Publications Warehouse

    U.S. Geological Survey

    2002-01-01

    The U.S. Geological Survey (USGS) is committed to meeting the Nation's needs for current base geographic data and maps. Our vision is that, by working with partners, we will provide the Nation with access to current, accurate, and nationally consistent digital data and topographic maps derived from those data. This synthesis of information, products, and capabilities, The National Map, will be a seamless, continuously maintained set of geographic base information that will serve as a foundation for integrating, sharing, and using other data easily and consistently.

  15. A Method for Teaching Topographic Map Interpretation

    ERIC Educational Resources Information Center

    Schuit, Walter

    2011-01-01

    Students learn how to read and interpret topographic maps by using a set of simplified map exercise cards. Students learn in the field as opposed to a traditional classroom. Map symbols, distance, direction, form, and relief are among the map interpretation topics taught with this method. The multiple-choice format of the exercise also allows for…

  16. A Watered-Down Topographic Map. Submarine Ring of Fire--Grades 6-8. Topographic and Bathymetric Maps.

    ERIC Educational Resources Information Center

    National Oceanic and Atmospheric Administration (DOC), Rockville, MD.

    This activity is designed to teach about topographic maps and bathymetric charts. Students are expected to create a topographic map from a model landform, interpret a simple topographic map, and explain the difference between topographic and bathymetric maps. The activity provides learning objectives, a list of needed materials, key vocabulary…

  17. Geometric accuracy of topographical objects at Polish topographic maps

    NASA Astrophysics Data System (ADS)

    Ławniczak, Radzym; Kubiak, Jarosław

    2016-06-01

    The objective of research concerned verifying the accuracy of the location and shape of selected lakes presented on topographical maps from various periods, drawn up on different scales. The area of research covered lakes situated in North-Western Poland on the Międzychód-Sieraków Lakeland. An analysis was performed of vector maps available in both analogue and digital format. The scales of these studies range from 1:50 000 to 1:10 000. The source materials were current for the years 1907 through 2013. The shape and location of lakes have been verified directly by means of field measurements performed using the GPS technology with an accuracy class of RTK. An analysis was performed of the location and shape of five lakes. The analysed water regions were vectorised, and their vector images were used to determine quantitative features: the area and length of the shoreline. Information concerning the analysed lakes obtained from the maps was verified on the basis of direct field measurements performed using a GPS RTK receiver. Use was made of georeferential corrections provided by the NAVGEO service or a virtual reference station generated by the ASG EUPOS system. A compilation of cartographic and field data formed the basis for a comparison of the actual area and the length of the shoreline of the studied lakes. Cartographic analyses made it possible to single out the most reliable cartographic sources, which could be used for the purposes of hydrographical analyses. The course of shorelines shows the attached map.

  18. 183. Photocopy of map (Twin Falls Canal Company). TOPOGRAPHICAL MAP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    183. Photocopy of map (Twin Falls Canal Company). TOPOGRAPHICAL MAP OF MILNER DAM SITE, TWIN FALLS COUNTY, MILNER, IDAHO; MAP, LEFT SIDE ONLY. CROSS REFERENCE: ID-15-192. - Milner Dam & Main Canal: Twin Falls Canal Company, On Snake River, 11 miles West of city of Burley, Idaho, Twin Falls, Twin Falls County, ID

  19. Learning-regulated context relevant topographical map.

    PubMed

    Hartono, Pitoyo; Hollensen, Paul; Trappenberg, Thomas

    2015-10-01

    Kohonen's self-organizing map (SOM) is used to map high-dimensional data into a low-dimensional representation (typically a 2-D or 3-D space) while preserving their topological characteristics. A major reason for its application is to be able to visualize data while preserving their relation in the high-dimensional input data space as much as possible. Here, we are seeking to go further by incorporating semantic meaning in the low-dimensional representation. In a conventional SOM, the semantic context of the data, such as class labels, does not have any influence on the formation of the map. As an abstraction of neural function, the SOM models bottom-up self-organization but not feedback modulation which is also ubiquitous in the brain. In this paper, we demonstrate a hierarchical neural network, which learns a topographical map that also reflects the semantic context of the data. Our method combines unsupervised, bottom-up topographical map formation with top-down supervised learning. We discuss the mathematical properties of the proposed hierarchical neural network and demonstrate its abilities with empirical experiments. PMID:25546864

  20. Landform Mapping Using Multiscale Topographic Analysis

    NASA Astrophysics Data System (ADS)

    Bliss, N. B.

    2008-12-01

    Many ecological and agricultural processes depend on topographic relationships. Topography strongly influences microclimate, the types and productivity of plants, biomass, evapotranspiration rates, carbon storage rates, and fire fuel accumulation. These factors in turn influence the water cycle, stream flow, water quality, and soil formation. Most previous topographic analysis methods have focused on the elevation of a given grid cell (pixel) and very localized measures of slope and aspect (e.g., computed from elevation in a 3x3 window). Some measures have moved beyond a strictly local relationship, such as the compound topographic index, which can be used as a soil wetness index. I introduce a new method of multiscale topographic analysis which can be applied to digital elevation model (DEM) data of any resolution. The method calculates slope and curvature (change of slope) of the land not only in relation to adjacent grid cells but also for much larger distances downstream. The algorithm uses a flow direction grid to create a synthetic stream network as a set of connected line segments (a vector dataset). The multiscale measures are stored on a node attribute table, where the nodes are the endpoints of line segments connecting the original DEM grid cells. A pointer is computed for directly accessing data for nodes at selected distances down the stream network. Baseline distances are selected by counting cells down the flow path by each power of two (1, 2, 4, 8, ... cells downstream). Slope and curvature measures are defined for each of these baselines and are queried to distinguish multiscale topographic characteristics. Several applications of these methods have been tested. A floodplain measure identifies areas that are relatively low on the landscape, even as elevation changes while moving from plains into hills or mountains (study area: South Dakota). The landscape may be partitioned to provide zones for ecological analysis, including selection of field

  1. An Interdisciplinary Theme: Topographic Maps and Plate Tectonics

    ERIC Educational Resources Information Center

    Concannon, James P.; Aulgur, Linda

    2011-01-01

    This is an interdisciplinary lesson designed for middle school students studying landforms and geological processes. Students create a two-dimensional topographic map from a three-dimensional landform that they create using clay. Students then use other groups' topographic maps to re-create landforms. Following this, students explore some basic…

  2. Topographic Map of Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Topographic map of the landing site, to a distance of 60 meters from the lander in the LSC coordinate system. The lander is shown schematically in the center; 2.5 meter radius circle (black) centered on the camera was not mapped. Gentle relief [root mean square (rms) elevation variation 0.5 m; rms a directional slope 4O] and organization of topography into northwest and northeast-trending ridges about 20 meters apart are apparent. Roughly 30% of the illustrated area is hidden from the camera behind these ridges. Contours (0.2 m interval) and color coding of elevations were generated from a digital terrain model, which was interpolated by kriging from approximately 700 measured points. Angular and parallax point coordinates were measured manually on a large (5 m length) anaglyphic uncontrolled mosaic and used to calculate Cartesian (LSC) coordinates. Errors in azimuth on the order of 10 are therefore likely; elevation errors were minimized by referencing elevations to the local horizon. The uncertainty in range measurements increases quadratically with range. Given a measurement error of 1/2 pixel, the expected precision in range is 0.3 meter at 10 meter range, and 10 meters at 60 meter range. Repeated measurements were made, compared, and edited for consistency to improve the range precision. Systematic errors undoubtedly remain and will be corrected in future maps compiled digitally from geometrically controlled images. Cartographic processing by U.S. Geological Survey.

    NOTE: original caption as published in Science Magazine

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  3. A topographic feature taxonomy for a U.S. national topographic mapping ontology

    USGS Publications Warehouse

    Varanka, Dalia E.

    2013-01-01

    Using legacy feature lists from the U.S. National Topographic Mapping Program of the twentieth century, a taxonomy of features is presented for purposes of developing a national topographic feature ontology for geographic mapping and analysis. After reviewing published taxonomic classifications, six basic classes are suggested; terrain, surface water, ecological regimes, built-up areas, divisions, and events. Aspects of ontology development are suggested as the taxonomy is described.

  4. Multibeam Laser Altimeter for Planetary Topographic Mapping

    NASA Technical Reports Server (NTRS)

    Garvin, J. B.; Bufton, J. L.; Harding, D. J.

    1993-01-01

    Laser altimetry provides an active, high-resolution, high-accuracy method for measurement of planetary and asteroid surface topography. The basis of the measurement is the timing of the roundtrip propagation of short-duration pulses of laser radiation between a spacecraft and the surface. Vertical, or elevation, resolution of the altimetry measurement is determined primarily by laser pulse width, surface-induced spreading in time of the reflected pulse, and the timing precision of the altimeter electronics. With conventional gain-switched pulses from solid-state lasers and nanosecond resolution timing electronics, submeter vertical range resolution is possible anywhere from orbital altitudes of approximately 1 km to altitudes of several hundred kilometers. Horizontal resolution is a function of laser beam footprint size at the surface and the spacing between successive laser pulses. Laser divergence angle and altimeter platform height above the surface determine the laser footprint size at the surface, while laser pulse repetition rate, laser transmitter beam configuration, and altimeter platform velocity determine the spacing between successive laser pulses. Multiple laser transmitters in a single laser altimeter instrument that is orbiting above a planetary or asteroid surface could provide across-track as well as along-track coverage that can be used to construct a range image (i.e., topographic map) of the surface. We are developing a pushbroom laser altimeter instrument concept that utilizes a linear array of laser transmitters to provide contiguous across-track and along-track data. The laser technology is based on the emerging monolithic combination of individual, 1-sq cm diode-pumped Nd:YAG laser pulse emitters. Details of the multi-emitter laser transmitter technology, the instrument configuration, and performance calculations for a realistic Discovery-class mission will be presented.

  5. 37. Topographical Map of Land of Atwater Kent Manufacturing Co., ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. Topographical Map of Land of Atwater Kent Manufacturing Co., 38th Ward, Philadelphia (before 1928) - Atwater Kent Manufacturing Company, North Plant, 5000 Wissahickon Avenue, Philadelphia, Philadelphia County, PA

  6. Exploring Arthur's Pass Topographic Map and Model Interpretation.

    ERIC Educational Resources Information Center

    Fastier, Murray; Macaulay, John

    1995-01-01

    Provides instructional materials, tasks, and activities to supplement a unit on map reading. Presents a two-page color topographical map of Arthur's Pass (New Zealand). Includes learning activities covering reading grid references, estimating distances, cross-sections, and sketch mapping. Briefly discusses and illustrates digital terrain models.…

  7. Children's Abilities in Topographic Map Reading.

    ERIC Educational Resources Information Center

    Carswell, Ronald J. B.

    Although over 40 studies have been done since 1925 on map reading, there is little understanding of children's ability to comprehend maps or the mental processes involved. Children's inability to read maps is well document, as are their improved skills after instruction. Yet map skills are part of the elementary curriculum. Success in teaching map…

  8. Topographic Brain Mapping: A Window on Brain Function?

    ERIC Educational Resources Information Center

    Karniski, Walt M.

    1989-01-01

    The article reviews the method of topographic mapping of the brain's electrical activity. Multiple electroencephalogram (EEG) electrodes and computerized analysis of the EEG signal are used to generate maps of frequency and voltage (evoked potential). This relatively new technique holds promise in the evaluation of children with behavioral and…

  9. Competition is a driving force in topographic mapping.

    PubMed

    Triplett, Jason W; Pfeiffenberger, Cory; Yamada, Jena; Stafford, Ben K; Sweeney, Neal T; Litke, Alan M; Sher, Alexander; Koulakov, Alexei A; Feldheim, David A

    2011-11-22

    Topographic maps are the primary means of relaying spatial information in the brain. Understanding the mechanisms by which they form has been a goal of experimental and theoretical neuroscientists for decades. The projection of the retina to the superior colliculus (SC)/tectum has been an important model used to show that graded molecular cues and patterned retinal activity are required for topographic map formation. Additionally, interaxon competition has been suggested to play a role in topographic map formation; however, this view has been recently challenged. Here we present experimental and computational evidence demonstrating that interaxon competition for target space is necessary to establish topography. To test this hypothesis experimentally, we determined the nature of the retinocollicular projection in Math5 (Atoh7) mutant mice, which have severely reduced numbers of retinal ganglion cell inputs into the SC. We find that in these mice, retinal axons project to the anteromedialj portion of the SC where repulsion from ephrin-A ligands is minimized and where their attraction to the midline is maximized. This observation is consistent with the chemoaffinity model that relies on axon-axon competition as a mapping mechanism. We conclude that chemical labels plus neural activity cannot alone specify the retinocollicular projection; instead axon-axon competition is necessary to create a map. Finally, we present a mathematical model for topographic mapping that incorporates molecular labels, neural activity, and axon competition. PMID:22065784

  10. Topographic map of Golden Gate Estates, Collier County, Florida

    USGS Publications Warehouse

    Jurado, Antonio

    1981-01-01

    Construction of canals related to land development in the Golden Gate Estates area of Collier County, Fla., has altered the natural drainage pattern of the watershed. The area of approximately 300 square miles was topographically mapped with a contour interval of 0.5 foot to assist in determining the effects of canal construction on the surface-water and ground-water resources in the watershed. The topographic map was prepared at a scale of 1:48,000 using aerial photography and ground-control points. (USGS)

  11. Retinal input instructs alignment of visual topographic maps

    PubMed Central

    Triplett, Jason W.; Owens, Melinda T.; Yamada, Jena; Lemke, Greg; Cang, Jianhua; Stryker, Michael P.; Feldheim, David A.

    2009-01-01

    SUMMARY Sensory information is represented in the brain in the form of topographic maps, in which neighboring neurons respond to adjacent external stimuli. In the visual system, the superior colliculus receives topographic projections from the retina and primary visual cortex (V1) that are aligned. Alignment may be achieved through the use of a gradient of shared axon guidance molecules, or through a retinal-matching mechanism in which axons that monitor identical regions of visual space align. To distinguish between these possibilities, we take advantage of genetically-engineered mice that we show have a duplicated functional retinocollicular map but only a single map in V1. Anatomical tracing revealed that the corticocollicular projection bifurcates to align with the duplicated retinocollicular map in a manner dependent on the normal pattern of spontaneous activity during development. These data suggest a general model in which convergent maps use coincident activity patterns to achieve alignment. PMID:19804762

  12. Fine resolution topographic mapping of the Jovian moons: a Ka-band high resolution topographic mapping interferometric synthetic aperture radar

    NASA Technical Reports Server (NTRS)

    Madsen, Soren N.; Carsey, Frank D.; Turtle, Elizabeth P.

    2003-01-01

    The topographic data set obtained by MOLA has provided an unprecedented level of information about Mars' geologic features. The proposed flight of JIMO provides an opportunity to accomplish a similar mapping of and comparable scientific discovery for the Jovian moons through us of an interferometric imaging radar analogous to the Shuttle radar that recently generated a new topographic map of Earth. A Ka-band single pass across-track synthetic aperture radar (SAR) interferometer can provide very high resolution surface elevation maps. The concept would use two antennas mounted at the ends of a deployable boom (similar to the Shuttle Radar Topographic Mapper) extended orthogonal to the direction of flight. Assuming an orbit altitude of approximately 100 km and a ground velocity of approximately 1.5 km/sec, horizontal resolutions at the 10 meter level and vertical resolutions at the sub-meter level are possible.

  13. Fine Resolution Topographic Mapping of the Jovian Moons: A Ka-Band High Resolution Topographic Mapping Interferometric Synthetic Aperture Radar

    NASA Technical Reports Server (NTRS)

    Madsen, S. N.; Carsey, F. D.; Turtle, E. P.

    2003-01-01

    The topographic data set obtained by MOLA has provided an unprecedented level of information about Mars' geologic features. The proposed flight of JIMO provides an opportunity to accomplish a similar mapping of and comparable scientific discovery for the Jovian moons through use of an interferometric imaging radar analogous to the Shuttle radar that recently generated a new topographic map of Earth. A Ka-band single pass across-track synthetic aperture radar (SAR) interferometer can provide very high resolution surface elevation maps. The concept would use two antennas mounted at the ends of a deployable boom (similar to the Shuttle Radar Topographic Mapper) extended orthogonal to the direction of flight. Assuming an orbit altitude of approximately 100km and a ground velocity of approximately 1.5 km/sec, horizontal resolutions at the 10 meter level and vertical resolutions at the sub-meter level are possible.

  14. Uas Topographic Mapping with Velodyne LiDAR Sensor

    NASA Astrophysics Data System (ADS)

    Jozkow, G.; Toth, C.; Grejner-Brzezinska, D.

    2016-06-01

    Unmanned Aerial System (UAS) technology is nowadays willingly used in small area topographic mapping due to low costs and good quality of derived products. Since cameras typically used with UAS have some limitations, e.g. cannot penetrate the vegetation, LiDAR sensors are increasingly getting attention in UAS mapping. Sensor developments reached the point when their costs and size suit the UAS platform, though, LiDAR UAS is still an emerging technology. One issue related to using LiDAR sensors on UAS is the limited performance of the navigation sensors used on UAS platforms. Therefore, various hardware and software solutions are investigated to increase the quality of UAS LiDAR point clouds. This work analyses several aspects of the UAS LiDAR point cloud generation performance based on UAS flights conducted with the Velodyne laser scanner and cameras. The attention was primarily paid to the trajectory reconstruction performance that is essential for accurate point cloud georeferencing. Since the navigation sensors, especially Inertial Measurement Units (IMUs), may not be of sufficient performance, the estimated camera poses could allow to increase the robustness of the estimated trajectory, and subsequently, the accuracy of the point cloud. The accuracy of the final UAS LiDAR point cloud was evaluated on the basis of the generated DSM, including comparison with point clouds obtained from dense image matching. The results showed the need for more investigation on MEMS IMU sensors used for UAS trajectory reconstruction. The accuracy of the UAS LiDAR point cloud, though lower than for point cloud obtained from images, may be still sufficient for certain mapping applications where the optical imagery is not useful.

  15. Model for Improvement of Learning Using Topographic Mapping.

    ERIC Educational Resources Information Center

    Andrews, David B.

    The paper develops a method for learning improvement which incorporates the learner in the development of the learning/instructional strategy. To this end, a rate limiting model using topographical brain mapping as an educational intervention is presented. It is suggested that such intervention programs focus on those factors which are…

  16. University Students' Conceptualization and Interpretation of Topographic Maps

    ERIC Educational Resources Information Center

    Clark, Douglas; Reynolds, Stephen; Lemanowski, Vivian; Stiles, Thomas; Yasar, Senay; Proctor, Sian; Lewis, Elizabeth; Stromfors, Charlotte; Corkins, James

    2008-01-01

    This study investigates the strategies and assumptions that college students entering an introductory physical geology laboratory use to interpret topographic maps, and follows the progress of the students during the laboratory to analyze changes in those strategies and assumptions. To elicit students' strategies and assumptions, we created and…

  17. New Large-Scale Topographic Maps of Planet Mars

    NASA Astrophysics Data System (ADS)

    Gehrke, S.; Lehmann, H.; Wahlisch, M.; Albertz, J.

    Introduction: The High Resolution Stereo Camera (HRSC) instrument is well suited for the special demands of stereophotogrammetry and cartography as well. Thus, color orthoimages, Digital Terrain Models (DTM), and - based on these two data sets - high quality topographic and thematic map products are generated, mainly in standard scale 1:200,000, i.e. the new Topographic Image Map Mars 1:200,000 map series. For supporting such a challenge and also aiming for automation of the mapping process, the cartographic software package Planetary Image Mapper (PIMap) has been developed at Technische Universität Berlin. Besides an overview of the cartographic concept and map generation, two recent projects - the mapping of the Iani Chaos region in three different scales and the generation of the first map sheets of the standard series for the north polar region - are described. The Cartographic Concept: The Topographic Image Map Mars 1:200,000 is defined as the standard map series of the Mars Express mission. In general, all map sheets are based on HRSC orthoimages, supplemented by contour lines derived from HRSC DTMs, topographic names, grids, and marginal information. The planet Mars is covered by 10,372 individual sheets in equal-area map projections, i.e. 10,324 of them within the ±85° latitude zone in Sinusoidal Projection and 48 around the poles in Lambert Azimuthal Equal-area Projection. While each of the quadrangles spans 2° in latitude, longitudinal extents increase from 2° near the equator up to 360° towards the poles in order to keep the mapped area approximately constant. The Martian reference body is the IAU 2000 Ellipsoid with an equatorial axis of 3396.19 km and a polar axis of 3376.20 km. Both Martian coordinate systems - i.e. the standard consisting of eastern longitudes and planetocentric latitudes as well as the formerly used system of western longitudes and planetographic latitudes - are shown within the map sheets. An areoid, i.e. the Martian geoid

  18. 12. Photograph of a topographic map. 'HOLSTON ORDNANCE WORKS, KINGSPORT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Photograph of a topographic map. 'HOLSTON ORDNANCE WORKS, KINGSPORT, TENNESSEE, VICINITY MAP: ENLARGED KINGSPORT AREA. WAR DEPARTMENT, INDUSTRIAL FACILITIES INVENTORY, PART I, SECTION 3.' From U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant A, Parts I, II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, Producer Gas Plant, Kingsport, Sullivan County, TN

  19. UAV Data Processing for Large Scale Topographical Mapping

    NASA Astrophysics Data System (ADS)

    Tampubolon, W.; Reinhardt, W.

    2014-06-01

    Large scale topographical mapping in the third world countries is really a prominent challenge in geospatial industries nowadays. On one side the demand is significantly increasing while on the other hand it is constrained by limited budgets available for mapping projects. Since the advent of Act Nr.4/yr.2011 about Geospatial Information in Indonesia, large scale topographical mapping has been on high priority for supporting the nationwide development e.g. detail spatial planning. Usually large scale topographical mapping relies on conventional aerial survey campaigns in order to provide high resolution 3D geospatial data sources. Widely growing on a leisure hobby, aero models in form of the so-called Unmanned Aerial Vehicle (UAV) bring up alternative semi photogrammetric aerial data acquisition possibilities suitable for relatively small Area of Interest (AOI) i.e. <5,000 hectares. For detail spatial planning purposes in Indonesia this area size can be used as a mapping unit since it usually concentrates on the basis of sub district area (kecamatan) level. In this paper different camera and processing software systems will be further analyzed for identifying the best optimum UAV data acquisition campaign components in combination with the data processing scheme. The selected AOI is covering the cultural heritage of Borobudur Temple as one of the Seven Wonders of the World. A detailed accuracy assessment will be concentrated within the object feature of the temple at the first place. Feature compilation involving planimetric objects (2D) and digital terrain models (3D) will be integrated in order to provide Digital Elevation Models (DEM) as the main interest of the topographic mapping activity. By doing this research, incorporating the optimum amount of GCPs in the UAV photo data processing will increase the accuracy along with its high resolution in 5 cm Ground Sampling Distance (GSD). Finally this result will be used as the benchmark for alternative geospatial

  20. Topographic indices for improved mapping of forested wetlands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The best management of wetlands and associated ecosystem services requires accurate and up to date knowledge of wetland location and character. Unfortunately even the most accurate US wetland maps contain relatively high levels of error in areas that are difficult to map, such as forests. Furthermor...

  1. Topographic and location map of Bonita Point Coast Guard and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Topographic and location map of Bonita Point Coast Guard and lighthouse station, June 1940, this drawing shows the Bonita Ridge access road retaining wall and general conditions at Fort Barry and Bonita Ridge (upper left) before the construction of Signal Corps Radar (S.C.R.) 296 Station 5 - Fort Barry, Signal Corps Radar 296, Station 5, Transmitter Building Foundation, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  2. A Map of Kilometer-Scale Topographic Roughness of Mercury

    NASA Astrophysics Data System (ADS)

    Kreslavsky, M. A.; Head, J. W., III; Kokhanov, A. A.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.; Kozlova, N. A.

    2014-12-01

    We present a new map of the multiscale topographic roughness of the northern circumpolar area of Mercury. The map utilizes high internal vertical precision surface ranging by the laser altimeter MLA onboard MESSENGER mission to Mercury. This map is analogous to global roughness maps that had been created by M.A.K. with collaborators for Mars (MOLA data) and the Moon (LOLA data). As measures of roughness, we used the interquartile range of along-track profile curvature at three baselines: 0.7 km, 2.8 km, and 11 km. Unlike in the cases of LOLA data for the Moon, and MOLA data for Mars, the MLA data allow high-quality roughness mapping only for a small part of the surface of the planet: the map covers 65N - 84N latitude zone, where the density of MLA data is the highest. The map captures the regional variations of the typical background topographic texture of the surface. The map shows the clear dichotomy between smooth northern plains and rougher cratered terrains. The lowered contrast of this dichotomy at the shortest (0.7 km) baseline indicates that regolith on Mercury is thicker and/or gardening processes are more intensive in comparison to the Moon, approximately by a factor of three. The map reveals sharp roughness contrasts within northern plains of Mercury that we interpret as geologic boundaries of volcanic plains of different age. In particular, the map suggests a younger volcanic plains unit inside Goethe basin and inside another unnamed stealth basin. -- Acknowledgement: Work on data processing was carried out at MIIGAiK by MAK, AAK, NAK and supported by Russian Science Foundation project 14-22-00197.

  3. Topographic maps of Serbia prior to the WWI

    NASA Astrophysics Data System (ADS)

    Kovács, B.

    2009-04-01

    Compilation of high or medium scale topographic surveys always played an important role in the geosciences of newly independent countries. Serbia formally has gained back its independency from the Turkish Empire sortly after the 1878 Congress of Berlin. The newly founded Institute of Military Geography in Beograd made efforts to complete a topographic series of 1:75,000 scale. Actually two serieses have been completed prior to the Balkan Wars of 1912-13, one with Latin and the other with the Cyrillic name descriptions, in French and Serbian languages, respectively. The scale of these map systems are identical to the Habsburg general mapping of Central Europe, covering also Serbia. As the Habsburg maps used the prime meridian of Ferro, their Serbian counterparts were using the one of Paris, which is a mere longitude shift of 20 degrees in round numbers. The geodetic basis behind the Serbian maps is probably the Habsburg triangulation in the Balkans (1871-75) - this would explain why the Vienna-centered Hermannskogel datum has been used also in Yugoslavia and Serbia even till nowadays. The French language series has red planar graphic elements (only the names, elevations and the railroad lines are written or drawn in back), blue, brown and green prints were used for waters, contours and vegetation. The Serbian language series mostly reminds to the modern maps albeit it has only three colors (black, brown and green).

  4. Topographical mapping system for radiological and hazardous environments acceptance testing

    SciTech Connect

    Armstrong, G.A.; Dochat, G.R.

    1997-12-01

    During the summer of 1996, the Topographical Mapping System (TMS) for hazardous and radiological environments and its accompanying three-dimensional (3-D) visualization tool, the Interactive Computer-Enhanced Remote-Viewing System (ICERVS), were delivered to Oak Ridge National Laboratory (ORNL). ORNL and Mechanical Technology, Inc., performed final acceptance testing of the TMS during the next eight months. The TMS was calibrated and characterized during this period. This paper covers the calibration, characterization, and acceptance testing of the TMS. Development of the TMS and ICERVS was initiated by the US Department of Energy (DOE) for the purpose of characterization and remediation of underground storage tanks (USTs) at DOE sites across the country. DOE required a 3-D, topographical mapping system suitable for use in hazardous and radiological environments. The intended application is the mapping of the interior of USTs as part of DOE`s waste characterization and remediation efforts and to obtain baseline data on the content of the storage tank interiors as well as data on changes in the tank contents and levels brought about by waste remediation steps. Initially targeted for deployment at the Hanford Washington site, the TMS is designed to be a self-contained, compact, and reconfigurable system that is capable of providing rapid, variable-resolution mapping information in poorly characterized workspaces with a minimum of operator intervention.

  5. Topographical mapping system for radiological and hazardous environments acceptance testing

    NASA Astrophysics Data System (ADS)

    Armstrong, Gary A.; Dochat, G. R.

    1997-09-01

    During the summer of 1996, the topographical mapping system (TMS) for hazardous and radiological environments and its accompanying three-dimensional (3-D) visualization tool, the interactive computer-enhanced remote-viewing system (ICERVS), were delivered to Oak Ridge National Laboratory (ORNL). ORNL and Mechanical Technology, Inc., performed final acceptance testing of the TMS during the next eight months. The TMS was calibrated and characterized during this period. This paper covers the calibration, characterization, and acceptance testing of the TMS. Development of the TMS and the ICERVS was initiated by the U.S. Department of Energy (DOE) for the purpose of characterization and remediation of underground storage tanks (USTs) at DOE sites across the country. DOE required a 3-D, topographical mapping system suitable for use in hazardous and radiological environments. The intended application is the mapping of the interior of USTs as part of DOE's waste characterization and remediation efforts and to obtain baseline data on the content of the storage tank interiors as well as data on changes in the tank contents and levels brought about by waste remediation steps. Initially targeted for deployment at the Hanford Washington site, the TMS is designed to be a self-contained, compact, reconfigurable system that is capable of providing rapid, variable-resolution mapping information in poorly characterized workspaces with a minimum of operator intervention.

  6. An Investigation of Automatic Change Detection for Topographic Map Updating

    NASA Astrophysics Data System (ADS)

    Duncan, P.; Smit, J.

    2012-08-01

    Changes to the landscape are constantly occurring and it is essential for geospatial and mapping organisations that these changes are regularly detected and captured, so that map databases can be updated to reflect the current status of the landscape. The Chief Directorate of National Geospatial Information (CD: NGI), South Africa's national mapping agency, currently relies on manual methods of detecting changes and capturing these changes. These manual methods are time consuming and labour intensive, and rely on the skills and interpretation of the operator. It is therefore necessary to move towards more automated methods in the production process at CD: NGI. The aim of this research is to do an investigation into a methodology for automatic or semi-automatic change detection for the purpose of updating topographic databases. The method investigated for detecting changes is through image classification as well as spatial analysis and is focussed on urban landscapes. The major data input into this study is high resolution aerial imagery and existing topographic vector data. Initial results indicate the traditional pixel-based image classification approaches are unsatisfactory for large scale land-use mapping and that object-orientated approaches hold more promise. Even in the instance of object-oriented image classification generalization of techniques on a broad-scale has provided inconsistent results. A solution may lie with a hybrid approach of pixel and object-oriented techniques.

  7. Topographic Mapping of Pluto and Charon Using New Horizons Data

    NASA Astrophysics Data System (ADS)

    Schenk, P. M.; Beyer, R. A.; Moore, J. M.; Spencer, J. R.; McKinnon, W. B.; Howard, A. D.; White, O. M.; Umurhan, O. M.; Singer, K.; Stern, S. A.; Weaver, H. A.; Young, L. A.; Ennico Smith, K.; Olkin, C.; Horizons Geology, New; Geophysics Imaging Team

    2016-06-01

    New Horizons 2015 flyby of the Pluto system has resulted in high-resolution topographic maps of Pluto and Charon, the most distant objects so mapped. DEM's over ~30% of each object were produced at 100-300 m vertical and 300-800 m spatial resolutions, in hemispheric maps and high-resolution linear mosaics. Both objects reveal more relief than was observed at Triton. The dominant 800-km wide informally named Sputnik Planum bright ice deposit on Pluto lies in a broad depression 3 km deep, flanked by dispersed mountains 3-5 km high. Impact craters reveal a wide variety of preservation states from pristine to eroded, and long fractures are several km deep with throw of 0-2 km. Topography of this magnitude suggests the icy shell of Pluto is relatively cold and rigid. Charon has global relief of at least 10 km, including ridges of 2-3 km and troughs of 3-5 km of relief. Impact craters are up to 6 km deep. Vulcan Planum consists of rolling plains and forms a topographic moat along its edge, suggesting viscous flow.

  8. Symobls and Meaning in Topographic Maps: Some Limintations Due to Aspects of Map Design.

    ERIC Educational Resources Information Center

    Keates, J. S.

    The approach to topographic map production has been highly organized and systematic with respect to scale, projection, grid, etc., so that the user can expect a high degree of locational accuracy. Less attention has been given by cartographers to symbolic information yielded by the map. Symbolization (information reduction) is required at all…

  9. Radargram of Mars' North Polar Layered Deposits with Topographic Map

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The upper image is a radargram from the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS), showing data from the subsurface of Mars in the layered deposits that surround the north pole. The lower image shows the position of the ground track on a topographic map of the area based on Mars Orbiter Laser Altimeter data. The images are 458 kilometers (285 miles) wide.

    The MARSIS echo trace splits into two traces to the right of center, at the point where the ground track crosses from the smooth plains onto the elevated layered deposits on the right. The upper trace is the echo from the surface of the deposits, while the lower trace is interpreted to be the boundary between the lower surface of the deposits and the underlying material. The strength of the lower echo suggests that the intervening material is nearly pure water ice. The time delay between the two echoes reaches a maximum of 21 microseconds at the right of the image, corresponding to a thickness of 1.8 kilometer (1.1 mile) of ice. The total elevation difference shown in the topographic map is about 2 kilometers (1.2 mile) between the lowest surface (magenta) and the highest (orange).

    MARSIS is an instrument on the European Space Agency's Mars Express orbiter. NASA and the Italian Space Agency jointly funded the instrument. The Mars Orbiter Laser Altimeter is an instrument on NASA's Mars Global Surveyor orbiter.

  10. Synaptic rewiring for topographic mapping and receptive field development.

    PubMed

    Bamford, Simeon A; Murray, Alan F; Willshaw, David J

    2010-05-01

    A model of topographic map refinement is presented which combines both weight plasticity and the formation and elimination of synapses, as well as both activity-dependent and activity-independent processes. The question of whether an activity-dependent process can refine a mapping created by an activity-independent process is addressed statistically. A new method of evaluating the quality of topographic projections is presented which allows independent consideration of the development of the centres and spatial variances of receptive fields for a projection. Synapse formation and elimination embed in the network topology changes in the weight distributions of synapses due to the activity-dependent learning rule used (spike-timing-dependent plasticity). In this model, the spatial variance of receptive fields can be reduced by an activity-dependent mechanism with or without spatially correlated inputs, but the accuracy of receptive field centres will not necessarily improve when synapses are formed based on distributions with on-average perfect topography. PMID:20176460

  11. Topographic Hub Maps of the Human Structural Neocortical Network

    PubMed Central

    Nijhuis, Emil H. J.; van Cappellen van Walsum, Anne-Marie; Norris, David G.

    2013-01-01

    Hubs within the neocortical structural network determined by graph theoretical analysis play a crucial role in brain function. We mapped neocortical hubs topographically, using a sample population of 63 young adults. Subjects were imaged with high resolution structural and diffusion weighted magnetic resonance imaging techniques. Multiple network configurations were then constructed per subject, using random parcellations to define the nodes and using fibre tractography to determine the connectivity between the nodes. The networks were analysed with graph theoretical measures. Our results give reference maps of hub distribution measured with betweenness centrality and node degree. The loci of the hubs correspond with key areas from known overlapping cognitive networks. Several hubs were asymmetrically organized across hemispheres. Furthermore, females have hubs with higher betweenness centrality and males have hubs with higher node degree. Female networks have higher small-world indices. PMID:23935801

  12. A Comparison of Spatial Analysis Methods for the Construction of Topographic Maps of Retinal Cell Density

    PubMed Central

    Garza-Gisholt, Eduardo; Hemmi, Jan M.; Hart, Nathan S.; Collin, Shaun P.

    2014-01-01

    Topographic maps that illustrate variations in the density of different neuronal sub-types across the retina are valuable tools for understanding the adaptive significance of retinal specialisations in different species of vertebrates. To date, such maps have been created from raw count data that have been subjected to only limited analysis (linear interpolation) and, in many cases, have been presented as iso-density contour maps with contour lines that have been smoothed ‘by eye’. With the use of stereological approach to count neuronal distribution, a more rigorous approach to analysing the count data is warranted and potentially provides a more accurate representation of the neuron distribution pattern. Moreover, a formal spatial analysis of retinal topography permits a more robust comparison of topographic maps within and between species. In this paper, we present a new R-script for analysing the topography of retinal neurons and compare methods of interpolating and smoothing count data for the construction of topographic maps. We compare four methods for spatial analysis of cell count data: Akima interpolation, thin plate spline interpolation, thin plate spline smoothing and Gaussian kernel smoothing. The use of interpolation ‘respects’ the observed data and simply calculates the intermediate values required to create iso-density contour maps. Interpolation preserves more of the data but, consequently includes outliers, sampling errors and/or other experimental artefacts. In contrast, smoothing the data reduces the ‘noise’ caused by artefacts and permits a clearer representation of the dominant, ‘real’ distribution. This is particularly useful where cell density gradients are shallow and small variations in local density may dramatically influence the perceived spatial pattern of neuronal topography. The thin plate spline and the Gaussian kernel methods both produce similar retinal topography maps but the smoothing parameters used may affect

  13. A Two-Phase Space Resection Model for Accurate Topographic Reconstruction from Lunar Imagery with PushbroomScanners

    PubMed Central

    Xu, Xuemiao; Zhang, Huaidong; Han, Guoqiang; Kwan, Kin Chung; Pang, Wai-Man; Fang, Jiaming; Zhao, Gansen

    2016-01-01

    Exterior orientation parameters’ (EOP) estimation using space resection plays an important role in topographic reconstruction for push broom scanners. However, existing models of space resection are highly sensitive to errors in data. Unfortunately, for lunar imagery, the altitude data at the ground control points (GCPs) for space resection are error-prone. Thus, existing models fail to produce reliable EOPs. Motivated by a finding that for push broom scanners, angular rotations of EOPs can be estimated independent of the altitude data and only involving the geographic data at the GCPs, which are already provided, hence, we divide the modeling of space resection into two phases. Firstly, we estimate the angular rotations based on the reliable geographic data using our proposed mathematical model. Then, with the accurate angular rotations, the collinear equations for space resection are simplified into a linear problem, and the global optimal solution for the spatial position of EOPs can always be achieved. Moreover, a certainty term is integrated to penalize the unreliable altitude data for increasing the error tolerance. Experimental results evidence that our model can obtain more accurate EOPs and topographic maps not only for the simulated data, but also for the real data from Chang’E-1, compared to the existing space resection model. PMID:27077855

  14. A Two-Phase Space Resection Model for Accurate Topographic Reconstruction from Lunar Imagery with PushbroomScanners.

    PubMed

    Xu, Xuemiao; Zhang, Huaidong; Han, Guoqiang; Kwan, Kin Chung; Pang, Wai-Man; Fang, Jiaming; Zhao, Gansen

    2016-01-01

    Exterior orientation parameters' (EOP) estimation using space resection plays an important role in topographic reconstruction for push broom scanners. However, existing models of space resection are highly sensitive to errors in data. Unfortunately, for lunar imagery, the altitude data at the ground control points (GCPs) for space resection are error-prone. Thus, existing models fail to produce reliable EOPs. Motivated by a finding that for push broom scanners, angular rotations of EOPs can be estimated independent of the altitude data and only involving the geographic data at the GCPs, which are already provided, hence, we divide the modeling of space resection into two phases. Firstly, we estimate the angular rotations based on the reliable geographic data using our proposed mathematical model. Then, with the accurate angular rotations, the collinear equations for space resection are simplified into a linear problem, and the global optimal solution for the spatial position of EOPs can always be achieved. Moreover, a certainty term is integrated to penalize the unreliable altitude data for increasing the error tolerance. Experimental results evidence that our model can obtain more accurate EOPs and topographic maps not only for the simulated data, but also for the real data from Chang'E-1, compared to the existing space resection model. PMID:27077855

  15. Topographic Mapping of Mars: Approaching the Human Scale

    NASA Astrophysics Data System (ADS)

    Kirk, R. L.; Howington-Kraus, E.; Soderblom, L. A.; Archinal, B. A.

    2002-12-01

    In only three decades, topographic mapping of Mars has progressed from the planetary to the personal scale. The first crude contour maps of the early 1970s, based on Earth-based radar and atmospheric occultation and sounding data, revealed such continental-scale features as the Tharsis bulge. Stereoanalysis of Mariner 9 and Viking Orbiter images filled in some of the details, yielding by the late 1980s a global digital elevation model (DEM) interpolated from 1-km contours and containing systematic errors of many km. This DEM was superseded in the 1990s by data from the Mars Orbiter Laser Altimeter (MOLA), with an accuracy <10 m vertically and ~ 100 m horizontally. MOLA has provided the definitive global map of Mars for the foreseeable future; its most significant weakness is its sample spacing (300 m along-track, with many gaps >1 km and a few up to 10 km between orbit tracks). Stereoanalysis of images from the narrow-angle Mars Orbiter Camera (MOC-NA) can be used to produce local DEMs with a vertical precision similar to MOLA (e.g., ~ 3 m for 3 m/pixel images with ~ 10° convergence), horizontal resolution of 3 pixels (~ 10 m for 3 m images), and control to MOLA for absolute accuracy comparable to the latter. Over 150 MOC-NA stereopairs have been identified, and more continue to be obtained. We will describe our use of the USGS cartographic system ISIS with commercial photogrammetric software SOCET SET (© BAE Systems) to produce DEMs from such pairs. This and similar work by other groups brings topographic mapping close to the scale of features seen from the ground and processes active at the present day. We are also using high-resolution stereo DEMs (and, in some cases, altimetry) as the starting point for calibration of photoclinometry, which yields DEMs with a horizontal resolution of one pixel and a local vertical precision of a small fraction of a pixel. The techniques we describe are directly applicable to other Mars imagers both present (THEMIS) and

  16. The topographic grain concept in DEM-based geomorphometric mapping

    NASA Astrophysics Data System (ADS)

    Józsa, Edina

    2016-04-01

    A common drawback of geomorphological analyses based on digital elevation datasets is the definition of search window size for the derivation of morphometric variables. The fixed-size neighbourhood determines the scale of the analysis and mapping, which can lead to the generalization of smaller surface details or the elimination of larger landform elements. The methods of DEM-based geomorphometric mapping are constantly developing into the direction of multi-scale landform delineation, but the optimal threshold for search window size is still a limiting factor. A possible way to determine the suitable value for the parameter is to consider the topographic grain principle (Wood, W. F. - Snell, J. B. 1960, Pike, R. J. et al. 1989). The calculation is implemented as a bash shell script for GRASS GIS to determine the optimal threshold for the r.geomorphon module. The approach relies on the potential of the topographic grain to detect the characteristic local ridgeline-to-channel spacing. By calculating the relative relief values with nested neighbourhood matrices it is possible to define a break-point where the increase rate of local relief encountered by the sample is significantly reducing. The geomorphons approach (Jasiewicz, J. - Stepinski, T. F. 2013) is a cell-based DEM classification method for the identification of landform elements at a broad range of scales by using line-of-sight technique. The landforms larger than the maximum lookup distance are broken down to smaller elements therefore the threshold needs to be set for a relatively large value. On the contrary, the computational requirements and the size of the study sites determine the upper limit for the value. Therefore the aim was to create a tool that would help to determine the optimal parameter for r.geomorphon tool. As a result it would be possible to produce more objective and consistent maps with achieving the full efficiency of this mapping technique. For the thorough analysis on the

  17. Acceleration of Topographic Map Production Using Semi-Automatic DTM from Dsm Radar Data

    NASA Astrophysics Data System (ADS)

    Rizaldy, Aldino; Mayasari, Ratna

    2016-06-01

    Badan Informasi Geospasial (BIG) is government institution in Indonesia which is responsible to provide Topographic Map at several map scale. For medium map scale, e.g. 1:25.000 or 1:50.000, DSM from Radar data is very good solution since Radar is able to penetrate cloud that usually covering tropical area in Indonesia. DSM Radar is produced using Radargrammetry and Interferrometry technique. The conventional method of DTM production is using "stereo-mate", the stereo image created from DSM Radar and ORRI (Ortho Rectified Radar Image), and human operator will digitizing masspoint and breakline manually using digital stereoplotter workstation. This technique is accurate but very costly and time consuming, also needs large resource of human operator. Since DSMs are already generated, it is possible to filter DSM to DTM using several techniques. This paper will study the possibility of DSM to DTM filtering using technique that usually used in point cloud LIDAR filtering. Accuracy of this method will also be calculated using enough numbers of check points. If the accuracy meets the requirement, this method is very potential to accelerate the production of Topographic Map in Indonesia.

  18. Topographic Maps: Rediscovering an Accessible Data Source for Land Cover Change Research

    ERIC Educational Resources Information Center

    McChesney, Ron; McSweeney, Kendra

    2005-01-01

    Given some limitations of satellite imagery for the study of land cover change, we draw attention here to a robust and often overlooked data source for use in student research: USGS topographic maps. Topographic maps offer an inexpensive, rapid, and accessible means for students to analyze land cover change over large areas. We demonstrate our…

  19. Derivation and Refinement of Topographic Maps of Io Using Voyager and Galileo Stereo Images

    NASA Astrophysics Data System (ADS)

    White, O. L.; Schenk, P. M.

    2011-03-01

    Customized ISIS software developed at LPI has been used to create topographic maps of different sites on Io using Galileo stereo images. Input parameters of the software have been refined in an attempt to achieve maps of the best quality.

  20. Tactile Robotic Topographical Mapping Without Force or Contact Sensors

    NASA Technical Reports Server (NTRS)

    Burke, Kevin; Melko, Joseph; Krajewski, Joel; Cady, Ian

    2008-01-01

    A method of topographical mapping of a local solid surface within the range of motion of a robot arm is based on detection of contact between the surface and the end effector (the fixture or tool at the tip of the robot arm). The method was conceived to enable mapping of local terrain by an exploratory robot on a remote planet, without need to incorporate delicate contact switches, force sensors, a vision system, or other additional, costly hardware. The method could also be used on Earth for determining the size and shape of an unknown surface in the vicinity of a robot, perhaps in an unanticipated situation in which other means of mapping (e.g., stereoscopic imaging or laser scanning with triangulation) are not available. The method uses control software modified to utilize the inherent capability of the robotic control system to measure the joint positions, the rates of change of the joint positions, and the electrical current demanded by the robotic arm joint actuators. The system utilizes these coordinate data and the known robot-arm kinematics to compute the position and velocity of the end effector, move the end effector along a specified trajectory, place the end effector at a specified location, and measure the electrical currents in the joint actuators. Since the joint actuator current is approximately proportional to the actuator forces and torques, a sudden rise in joint current, combined with a slowing of the joint, is a possible indication of actuator stall and surface contact. Hence, even though the robotic arm is not equipped with contact sensors, it is possible to sense contact (albeit with reduced sensitivity) as the end effector becomes stalled against a surface that one seeks to measure.

  1. Long-term development of the Czech landscape studied on the basis of old topographic maps

    NASA Astrophysics Data System (ADS)

    Skokanová, H.; Havlíček, M.

    2009-04-01

    The paper deals with long-term land use changes in the Czech Republic with the help of old topographic maps. Departments of Landscape Ecology and GIS Applications from the Silva Tarouca Research Institute for Landscape and Ornamental Gardening, v.v.i. study these changes mainly in the research project MSM 6293359101 Research into sources and indicators of biodiversity in cultural landscape in the context of its fragmentation dynamics, the subpart Quantitative analysis of the dynamics of the Czech landscape development. In this paper, the authors concentrate mainly on map sources, which were acquired for the purpose of the project and also introduce partial results. Maps, which are the sources for the analyses, are following: maps from 2nd Austrian military survey in the scale 1:28 800 (created for the territory of the Czech Republic in the period 1836-1852), maps from 3rd Austrian military survey in the scale 1:25 000 (created for the Czech Republic in the period 1876-1880), Czechoslovak military topographic maps in the scale 1:25 000 from 1950s and 1990s, and Czech topographic base maps in the scale 1:10 000 from 2002-2006. It is necessary to complete maps of the 2nd and 3rd Austrian military survey thanks to their incompleteness, mainly along state borders. Also maps from 1nd Austrian military survey in the scale 1:28 800 (created for the Czech Republic in the period 1764-1783) are available; however, their usage for the accurate analyses in the GIS environment is restricted by their poor cartographic accuracy. Apart of the above mentioned maps, there has been progress in collecting maps from the interwar and war period (revised maps of the 3rd Austrian military survey maps, maps of the provisional military survey from 1923-1933, maps of definitive military survey from 1934-1938 and maps from survey of Moravian part of the Protectorate of Bohemia and Moravia, so called Messtischblätter from 1939-1945). Maps from five periods are manually vectorised in the GIS

  2. Maps of Lunar Topographic Roughness: Correlation with Geological Features

    NASA Astrophysics Data System (ADS)

    Kreslavsky, M. A.; Head, J. W.; Neumann, G. A.; Zuber, M. T.; Smith, D. E.

    2012-12-01

    Lunar Orbiter Laser Altimeter LOLA [Smith et al. 2010 Space Sci. Rev. 150, 209] on board the Lunar Reconnaissance Orbiter is accumulating high-precision lunar surface elevation measurements. This data set is an excellent source for mapping lunar topographic roughness [Rosenburg et al. 2011 JGR 116, E02001]. Such maps are useful in planetary geology for the following reasons. (1) Roughness maps provide a convenient one-glance synoptic overview of small-scale textures. (2) They help focus on typical background topography, while researcher's eyes usually pick prominent features. (3) Roughness maps utilize the exceptional along-orbit precision of laser altimeter data. In a series of roughness maps that we present here, we use the interquartile range of along-profile curvature at a given baseline as a measure of roughness. We use a progression of baselines starting from the double LOLA probing step: 0.12, 0.46, 0.92, 1.8 km. We also show some useful color composites combining these maps and showing the scale dependence of roughness. Available data allow roughness mapping at 8 pixels per degree resolution. The nature of the lunar roughness changes abruptly at sub-km scale. At 0.46 km baseline and longer, the most prominent feature on the roughness maps is the dichotomy between smooth maria and rough highlands. At 0.12 km baseline, the mare/highland boundary disappears; some mare surfaces are rougher and some are smoother than typical highlands. At this baseline the surface topography is controlled by regolith gardening and reflects small-scale resurfacing during the Copernican and Eratosthenian periods, while for longer baselines the topography is defined by bedrock geology and "remembers" Imbrian and earlier events. At short scales (0.12 km baseline) both the roughest and the smoothest terrains are related to Copernican-aged large impact craters. Craters themselves and their proximal ejecta are extremely rough; the roughest ejecta is separated from craters by prominent

  3. Develop Advanced Nonlinear Signal Analysis Topographical Mapping System

    NASA Technical Reports Server (NTRS)

    Jong, Jen-Yi

    1997-01-01

    During the development of the SSME, a hierarchy of advanced signal analysis techniques for mechanical signature analysis has been developed by NASA and AI Signal Research Inc. (ASRI) to improve the safety and reliability for Space Shuttle operations. These techniques can process and identify intelligent information hidden in a measured signal which is often unidentifiable using conventional signal analysis methods. Currently, due to the highly interactive processing requirements and the volume of dynamic data involved, detailed diagnostic analysis is being performed manually which requires immense man-hours with extensive human interface. To overcome this manual process, NASA implemented this program to develop an Advanced nonlinear signal Analysis Topographical Mapping System (ATMS) to provide automatic/unsupervised engine diagnostic capabilities. The ATMS will utilize a rule-based Clips expert system to supervise a hierarchy of diagnostic signature analysis techniques in the Advanced Signal Analysis Library (ASAL). ASAL will perform automatic signal processing, archiving, and anomaly detection/identification tasks in order to provide an intelligent and fully automated engine diagnostic capability. The ATMS has been successfully developed under this contract. In summary, the program objectives to design, develop, test and conduct performance evaluation for an automated engine diagnostic system have been successfully achieved. Software implementation of the entire ATMS system on MSFC's OISPS computer has been completed. The significance of the ATMS developed under this program is attributed to the fully automated coherence analysis capability for anomaly detection and identification which can greatly enhance the power and reliability of engine diagnostic evaluation. The results have demonstrated that ATMS can significantly save time and man-hours in performing engine test/flight data analysis and performance evaluation of large volumes of dynamic test data.

  4. Mapping long-term temporal change in imperviousness using topographic maps

    NASA Astrophysics Data System (ADS)

    Miller, James D.; Grebby, Stephen

    2014-08-01

    Change in urban land use and impervious surface cover are valuable sources of information for determining the environmental impacts of urban development. However, our understanding of these impacts is limited due to the general lack of historical data beyond the last few decades. This study presents two methodologies for mapping and revealing long-term change in urban land use and imperviousness from topographic maps. Method 1 involves the generation of maps of fractional impervious surface for direct computation of catchment-level imperviousness. Method 2 generates maps of urban land use for subsequent computation of estimates of catchment imperviousness based on an urban extent index. Both methods are applied to estimate change in catchment imperviousness in a town in the South of England, at decadal intervals for the period 1960-2010. The performance of each method is assessed using contemporary reference data obtained from aerial photographs, with the results indicating that both methods are capable of providing good estimates of catchment imperviousness. Both methods reveal that peri-urban developments within the study area have undergone a significant expansion of impervious cover over the period 1960-2010, which is likely to have resulted in changes to the hydrological response of the previously rural areas. Overall, results of this study suggest that topographic maps provide a useful source for determining long-term change in imperviousness in the absence of suitable data, such as remotely sensed imagery. Potential applications of the two methods presented here include hydrological modelling, environmental investigations and urban planning.

  5. Flood inundation mapping uncertainty introduced by topographic data accuracy, geometric configuration and modeling approach

    NASA Astrophysics Data System (ADS)

    Papaioannou, G.; Loukas, Athanasios

    2010-05-01

    Floodplain modeling is a recently new and applied method in river engineering discipline and is essential for prediction of flood hazards. The issue of flood inundation of upland environments with topographically complex floodplains is an understudied subject. In most areas of the U.S.A., the use of topographic information derived from Light Detection and Ranging (LIDAR) has improved the quality of river flood inundation predictions. However, such high quality topographical data are not available in most countries and the necessary information is obtained by topographical survey and/or topographical maps. Furthermore, the optimum dimensionality of hydraulic models, cross-section configuration in one-dimensional (1D) models, mesh resolution in two-dimensional models (2D) and modeling approach is not well studied or documented. All these factors introduce significant uncertainty in the evaluation of the floodplain zoning. This study addresses some of these issues by comparing flood inundation maps developed using different topography, geometric description and modeling approach. The methodology involves use of topographic datasets with different horizontal resolutions, vertical accuracies and bathymetry details. Each topographic dataset is used to create a flood inundation map for different cross-section configurations using 1D (HEC-RAS) model, and different mesh resolutions using 2D models for steady state and unsteady state conditions. Comparison of resulting maps indicates the uncertainty introduced in floodplain modeling by the horizontal resolution and vertical accuracy of topographic data and the different modeling approaches.

  6. Accuracy assessment of topographic mapping using UAV image integrated with satellite images

    NASA Astrophysics Data System (ADS)

    Azmi, S. M.; Ahmad, Baharin; Ahmad, Anuar

    2014-02-01

    Unmanned Aerial Vehicle or UAV is extensively applied in various fields such as military applications, archaeology, agriculture and scientific research. This study focuses on topographic mapping and map updating. UAV is one of the alternative ways to ease the process of acquiring data with lower operating costs, low manufacturing and operational costs, plus it is easy to operate. Furthermore, UAV images will be integrated with QuickBird images that are used as base maps. The objective of this study is to make accuracy assessment and comparison between topographic mapping using UAV images integrated with aerial photograph and satellite image. The main purpose of using UAV image is as a replacement for cloud covered area which normally exists in aerial photograph and satellite image, and for updating topographic map. Meanwhile, spatial resolution, pixel size, scale, geometric accuracy and correction, image quality and information contents are important requirements needed for the generation of topographic map using these kinds of data. In this study, ground control points (GCPs) and check points (CPs) were established using real time kinematic Global Positioning System (RTK-GPS) technique. There are two types of analysis that are carried out in this study which are quantitative and qualitative assessments. Quantitative assessment is carried out by calculating root mean square error (RMSE). The outputs of this study include topographic map and orthophoto. From this study, the accuracy of UAV image is ± 0.460 m. As conclusion, UAV image has the potential to be used for updating of topographic maps.

  7. DATA QUALIFICATION REPORT: DATA QUALIFICATION REPORT FOR 1991 1:1200 TOPOGRAPHIC MAPS FOR USE ON THE YUCCA MOUNTAIN PROJECT

    SciTech Connect

    M.F. Knop; T.A. Grant; R.W. Bonisolli

    2005-06-25

    This Data Qualification Report (DQR) is prepared in accordance with the provisions of AP-SIII.2Q, Rev. 0, ICN 3, Qualification of Unqualified Data and the Documentation of Rationale for Accepted Data and Data Qualification Plan for 1991 Topographic Maps 1:1200 Scale for use on the Yucca Mountain Project, DQP-WHS-CI-000001, Rev. 00 (BSC 2002a). This DQR presents an evaluation of a set of 90 topographic sheets at 1:1200 scale (and an associated electronic file) that covers an approximate 18 square mile area surrounding the proposed Yucca Mountain Project repository surface facilities location in Midway Valley, Nevada. These maps, that require qualification, are now being used to determine the physical characteristics of watershed sub-areas, interconnecting channels, and drainage channel cross-sections for hydrologic engineering studies of the north portal pad and vicinity. The result of this effort is to qualify one data tracking number (DTN) containing the electronic version of the mapping data. This DTN is: M09906COV98462.000. Coverage: TOP02FTS. The underlying quality assurance (QA) issue associated with these topographic maps is that the maps were originally designated as not for use in the design of items important to safety, waste isolation, and/or of programmatic importance. The maps were therefore generated outside the U.S. Department of Energy Office of Civilian Radioactive Waste Management (OCRWM) QA program. Based on a comparison with corroborating information, this report concludes that the topographic maps are qualified. The comparison found that the mapping was reasonably accurate when compared with other mapping and survey data within the coverage area of the maps. Relative map accuracy was found to be very good and suitable for the hydrologic engineering studies being considered. Absolute accuracy is good but could not be demonstrated to comply with national map accuracy standards. Point locations that require high absolute accuracy should be

  8. Develop advanced nonlinear signal analysis topographical mapping system

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Space Shuttle Main Engine (SSME) has been undergoing extensive flight certification and developmental testing, which involves some 250 health monitoring measurements. Under the severe temperature, pressure, and dynamic environments sustained during operation, numerous major component failures have occurred, resulting in extensive engine hardware damage and scheduling losses. To enhance SSME safety and reliability, detailed analysis and evaluation of the measurements signal are mandatory to assess its dynamic characteristics and operational condition. Efficient and reliable signal detection techniques will reduce catastrophic system failure risks and expedite the evaluation of both flight and ground test data, and thereby reduce launch turn-around time. The basic objective of this contract are threefold: (1) develop and validate a hierarchy of innovative signal analysis techniques for nonlinear and nonstationary time-frequency analysis. Performance evaluation will be carried out through detailed analysis of extensive SSME static firing and flight data. These techniques will be incorporated into a fully automated system; (2) develop an advanced nonlinear signal analysis topographical mapping system (ATMS) to generate a Compressed SSME TOPO Data Base (CSTDB). This ATMS system will convert tremendous amount of complex vibration signals from the entire SSME test history into a bank of succinct image-like patterns while retaining all respective phase information. High compression ratio can be achieved to allow minimal storage requirement, while providing fast signature retrieval, pattern comparison, and identification capabilities; and (3) integrate the nonlinear correlation techniques into the CSTDB data base with compatible TOPO input data format. Such integrated ATMS system will provide the large test archives necessary for quick signature comparison. This study will provide timely assessment of SSME component operational status, identify probable causes of

  9. Develop advanced nonlinear signal analysis topographical mapping system

    NASA Technical Reports Server (NTRS)

    Jong, Jen-Yi

    1993-01-01

    The SSME has been undergoing extensive flight certification and developmental testing, which involves some 250 health monitoring measurements. Under the severe temperature pressure, and dynamic environments sustained during operation, numerous major component failures have occurred, resulting in extensive engine hardware damage and scheduling losses. To enhance SSME safety and reliability, detailed analysis and evaluation of the measurements signal are mandatory to assess its dynamic characteristics and operational condition. Efficient and reliable signal detection techniques will reduce catastrophic system failure risks and expedite the evaluation of both flight and ground test data, and thereby reduce launch turn-around time. The basic objective of this contract are threefold: (1) Develop and validate a hierarchy of innovative signal analysis techniques for nonlinear and nonstationary time-frequency analysis. Performance evaluation will be carried out through detailed analysis of extensive SSME static firing and flight data. These techniques will be incorporated into a fully automated system. (2) Develop an advanced nonlinear signal analysis topographical mapping system (ATMS) to generate a Compressed SSME TOPO Data Base (CSTDB). This ATMS system will convert tremendous amounts of complex vibration signals from the entire SSME test history into a bank of succinct image-like patterns while retaining all respective phase information. A high compression ratio can be achieved to allow the minimal storage requirement, while providing fast signature retrieval, pattern comparison, and identification capabilities. (3) Integrate the nonlinear correlation techniques into the CSTDB data base with compatible TOPO input data format. Such integrated ATMS system will provide the large test archives necessary for a quick signature comparison. This study will provide timely assessment of SSME component operational status, identify probable causes of malfunction, and indicate

  10. Vector Topographic Map Data over the BOREAS NSA and SSA in SIF Format

    NASA Technical Reports Server (NTRS)

    Knapp, David; Nickeson, Jaime; Hall, Forrest G. (Editor)

    2000-01-01

    This data set contains vector contours and other features of individual topographic map sheets from the National Topographic Series (NTS). The map sheet files were received in Standard Interchange Format (SIF) and cover the BOReal Ecosystem-Atmosphere Study (BOREAS) Northern Study Area (NSA) and Southern Study Area (SSA) at scales of 1:50,000 and 1:250,000. The individual files are stored in compressed Unix tar archives.

  11. Landscape features, standards, and semantics in U.S. national topographic mapping databases

    USGS Publications Warehouse

    Varanka, Dalia

    2009-01-01

    The objective of this paper is to examine the contrast between local, field-surveyed topographical representation and feature representation in digital, centralized databases and to clarify their ontological implications. The semantics of these two approaches are contrasted by examining the categorization of features by subject domains inherent to national topographic mapping. When comparing five USGS topographic mapping domain and feature lists, results indicate that multiple semantic meanings and ontology rules were applied to the initial digital database, but were lost as databases became more centralized at national scales, and common semantics were replaced by technological terms.

  12. Mapping mean total annual precipitation in Belgium, by investigating the scale of topographic control at the regional scale

    NASA Astrophysics Data System (ADS)

    Meersmans, J.; Van Weverberg, K.; De Baets, S.; De Ridder, F.; Palmer, S. J.; van Wesemael, B.; Quine, T. A.

    2016-09-01

    Accurate precipitation maps are essential for ecological, environmental, element cycle and hydrological models that have a spatial output component. It is well known that topography has a major influence on the spatial distribution of precipitation and that increasing topographical complexity is associated with increased spatial heterogeneity in precipitation. This means that when mapping precipitation using classical interpolation techniques (e.g. regression, kriging, spline, inverse distance weighting, etc.), a climate measuring network with higher spatial density is needed in mountainous areas in order to obtain the same level of accuracy as compared to flatter regions. In this study, we present a mean total annual precipitation mapping technique that combines topographical information (i.e. elevation and slope orientation) with average total annual rain gauge data in order to overcome this problem. A unique feature of this paper is the identification of the scale at which topography influences the precipitation pattern as well as the direction of the dominant weather circulation. This method was applied for Belgium and surroundings and shows that the identification of the appropriate scale at which topographical obstacles impact precipitation is crucial in order to obtain reliable mean total annual precipitation maps. The dominant weather circulation is determined at 260°. Hence, this approach allows accurate mapping of mean annual precipitation patterns in regions characterized by rather high topographical complexity using a climate data network with a relatively low density and/or when more advanced precipitation measurement techniques, such as radar, aren't available, for example in the case of historical data.

  13. THEMIS high-resolution digital terrain: Topographic and thermophysical mapping of Gusev Crater, Mars

    NASA Astrophysics Data System (ADS)

    Cushing, G. E.; Titus, T. N.; Soderblom, L. A.; Kirk, R. L.

    2009-07-01

    We discuss a new technique to generate high-resolution digital terrain models (DTMs) and to quantitatively derive and map slope-corrected thermophysical properties such as albedo, thermal inertia, and surface temperatures. This investigation is a continuation of work started by Kirk et al. (2005), who empirically deconvolved Thermal Emission Imaging System (THEMIS) visible and thermal infrared data of this area, isolating topographic information that produced an accurate DTM. Surface temperatures change as a function of many variables such as slope, albedo, thermal inertia, time, season, and atmospheric opacity. We constrain each of these variables to construct a DTM and maps of slope-corrected albedo, slope- and albedo-corrected thermal inertia, and surface temperatures across the scene for any time of day or year and at any atmospheric opacity. DTMs greatly facilitate analyses of the Martian surface, and the MOLA global data set is not finely scaled enough (128 pixels per degree, ˜0.5 km per pixel near the equator) to be combined with newer data sets (e.g., High Resolution Imaging Science Experiment, Context Camera, and Compact Reconnaissance Imaging Spectrometer for Mars at ˜0.25, ˜6, and ˜20 m per pixel, respectively), so new techniques to derive high-resolution DTMs are always being explored. This paper discusses our technique of combining a set of THEMIS visible and thermal infrared observations such that albedo and thermal inertia variations within the scene are eliminated and only topographic variations remain. This enables us to produce a high-resolution DTM via photoclinometry techniques that are largely free of albedo-induced errors. With this DTM, THEMIS observations, and a subsurface thermal diffusion model, we generate slope-corrected maps of albedo, thermal inertia, and surface temperatures. In addition to greater accuracy, these products allow thermophysical properties to be directly compared with topography.

  14. The Design and Product of National 1:1000000 Cartographic Data of Topographic Map

    NASA Astrophysics Data System (ADS)

    Wang, Guizhi

    2016-06-01

    National administration of surveying, mapping and geoinformation started to launch the project of national fundamental geographic information database dynamic update in 2012. Among them, the 1:50000 database was updated once a year, furthermore the 1:250000 database was downsized and linkage-updated on the basis. In 2014, using the latest achievements of 1:250000 database, comprehensively update the 1:1000000 digital line graph database. At the same time, generate cartographic data of topographic map and digital elevation model data. This article mainly introduce national 1:1000000 cartographic data of topographic map, include feature content, database structure, Database-driven Mapping technology, workflow and so on.

  15. Identification of topographic elements composition based on landform boundaries from radar interferometry segmentation (preliminary study on digital landform mapping)

    NASA Astrophysics Data System (ADS)

    Widyatmanti, Wirastuti; Wicaksono, Ikhsan; Dinta Rahma Syam, Prima

    2016-06-01

    Dense vegetation that covers most landscapes in Indonesia becomes a common limitation in mapping the landforms in tropical region. This paper aims to examine the use of radar interferometry for landform mapping in tropical region; to examine the application of segmentation method to develop landform type boundaries; and to identify the topographic elements composition for each type of landform. Using Idrisi® and “eCognition ®” softwares, toposhape analysis, segmentation and multi-spectral classification were applied to identify the composition of topographic elements i.e. the types of land-cover from Landsat 8, elevation, slope, relief intensity and curvatures from SRTM (DEM). Visual interpretation on DEM and land-cover fusion imagery was conducted to derive basic control maps of landform and land-cover. The result shows that in segmentation method, shape and compactness levels are essential in obtaining land-cover, elevation, and slope class units to determine the most accurate class borders of each element. Despite a complex procedure applied in determining landform classification, the combination of topographic elements segmentation result presents a distinct border of each landform class. The comparison between landform maps derived from segmentation process and visual interpretation method demonstrates slight dissimilarities, meaning that multi-stage segmentation approach can improve and provide more effective digital landform mapping method in tropical region. Topographic elements on each type of landforms show distinctive composition key containing the percentage of each curvature elements per area unit. Supported by GIS programming and modeling in the future, this finding is significant in reducing effort in landform mapping using visual interpretation method for a very large coverage but in detail scale level.

  16. Data-Driven Topographic Feature Selection for Mean Wind Speed Mapping

    NASA Astrophysics Data System (ADS)

    Foresti, L.; Pozdnoukhov, A.; Kanevski, M.

    2009-04-01

    Accurate spatial mapping of long term mean wind speeds is of great importance for renewable resources evaluation and wind farm location planning. This task is conventionally approached with a physical model further corrected with some geostatistical or semi-empirical method to take into account local topography and land cover effects. In mountainous regions of complex topographies, however, the evaluation of mean wind speed with this procedure is less precise. A variety of small-scale topographic features has to be incorporated into the model to take into account the factors affecting the wind speed, such as hill and tunnel effects. Large number of topographic features can be computed from digital elevation models to be integrated into a prediction model. Spatial prediction of the wind speeds by using a large set of input features is a high dimensional and non-linear problem. In conventional scheme, one relies here on many empirical correction coefficients and various topographic indices to take into account the influence of terrain. However, there is an emerging field of machine learning algorithms, which are the data-driven methods well-suited to solve such problems. They are aimed at modelling the non-linear dependencies between the high dimensional input features and a target variable such as the wind speed. There is a noticeable interest for using these methods for wind mapping. The presented research provides an application of machine learning methods (neural networks and support vector methods) for spatial prediction of mean wind speeds with a particular attention paid to the problem of feature selection. The number of features which can be generated from digital elevation model is countless as the features can be computed at various spatial scales. For example, a difference of terrains smoothed at different spatial scales enables to highlight the ridges and valleys. Feature selection methods allow finding the features and correspondingly the spatial scales

  17. A Topographic Image Map of the Sabrina Valles Region Including Information on Large Martian Impact Craters

    NASA Astrophysics Data System (ADS)

    Gehrke, S.; Köhring, R.; Barlow, N. G.; Gwinner, K.; Scholten, F.; Lehmann, H.; Albertz, J.

    2007-03-01

    The Catalog of Large Martian Impact Craters provides detailed information on 42,283 craters >5 km; it is planned to be integrated in the Topographic Image Map Mars 1:200,000 series. Such an update is shown in a special target map, based on HRSC data.

  18. Evaluating a topographical mapping from speech acoustics to tongue positions

    SciTech Connect

    Hogden, J.; Heard, M.

    1995-05-01

    The {ital continuity} {ital mapping} algorithm---a procedure for learning to recover the relative positions of the articulators from speech signals---is evaluated using human speech data. The advantage of continuity mapping is that it is an unsupervised algorithm; that is, it can potentially be trained to make a mapping from speech acoustics to speech articulation without articulator measurements. The procedure starts by vector quantizing short windows of a speech signal so that each window is represented (encoded) by a single number. Next, multidimensional scaling is used to map quantization codes that were temporally close in the encoded speech to nearby points in a {ital continuity} {ital map}. Since speech sounds produced sufficiently close together in time must have been produced by similar articulator configurations, and speech sounds produced close together in time are close to each other in the continuity map, sounds produced by similar articulator positions should be mapped to similar positions in the continuity map. The data set used for evaluating the continuity mapping algorithm is comprised of simultaneously collected articulator and acoustic measurements made using an electromagnetic midsagittal articulometer on a human subject. Comparisons between measured articulator positions and those recovered using continuity mapping will be presented.

  19. Comparison of High Resolution Topographic Data Sources (SAR, IfSAR, and LiDAR) for Storm Surge Hazard Maps

    NASA Astrophysics Data System (ADS)

    Suarez, J. K. B.; Santiago, J. T.; Muldong, T. M. M.; Lagmay, A. M. A.; Caro, C. V.; Ramos, M.

    2014-12-01

    As an archipelagic country, the Philippines has experienced multiple storm surge threats. Moreover, the country's location, adjacent to the Pacific Ocean, results in an average of eight to nine typhoons that make landfall in a year. Storm surge hazard maps require high resolution topographic data to illustrate water inflow in the event of storm surges in vulnerable coastal areas and for accurate boundaries and coastline. Furthermore, potential hazard areas tend to be generalized in lower resolution data. The objective of this research is to compare three sources where accurate and quality storm surge hazard maps will draw bases from. For this purpose, the researcher used and compared SAR, IfSAR and LiDAR. The study involved comparing maps from different topographic data sources in Tacloban, in the province of Leyte. This area was one of the most heavily stricken areas during typhoon Haiyan where more than 6,000 people died and P34.37 billion worth of property was destroyed. In the comparison of the three sources, the following had be taken into consideration: cost of acquiring data, processing time, purpose, and the results. The research learned the following: Synthetic Aperture Radar or SAR produces data with a 30 meter resolution, while Interferometric Synthetic Aperture Radar (IfSAR) offers a resolution of 5 meters. Light Detection and Ranging (LiDAR) has the highest resolution of the three with 1 meter. In addition, higher costs are paid for more detailed topographic data. Also, processing time takes longer for finer details due to the memory of the computer units used for modelling. The sources were also evaluated on the necessity of the scale at which the maps are needed for specific purposes such as practicality and direct disaster response. Results from the maps have been validated through interviews with the locals on the experience of actual storm surges. Through this study, the researcher concluded that although LiDAR can offer a more detailed and

  20. Accurately Mapping M31's Microlensing Population

    NASA Astrophysics Data System (ADS)

    Crotts, Arlin

    2004-07-01

    We propose to augment an existing microlensing survey of M31 with source identifications provided by a modest amount of ACS {and WFPC2 parallel} observations to yield an accurate measurement of the masses responsible for microlensing in M31, and presumably much of its dark matter. The main benefit of these data is the determination of the physical {or "einstein"} timescale of each microlensing event, rather than an effective {"FWHM"} timescale, allowing masses to be determined more than twice as accurately as without HST data. The einstein timescale is the ratio of the lensing cross-sectional radius and relative velocities. Velocities are known from kinematics, and the cross-section is directly proportional to the {unknown} lensing mass. We cannot easily measure these quantities without knowing the amplification, hence the baseline magnitude, which requires the resolution of HST to find the source star. This makes a crucial difference because M31 lens m ass determinations can be more accurate than those towards the Magellanic Clouds through our Galaxy's halo {for the same number of microlensing events} due to the better constrained geometry in the M31 microlensing situation. Furthermore, our larger survey, just completed, should yield at least 100 M31 microlensing events, more than any Magellanic survey. A small amount of ACS+WFPC2 imaging will deliver the potential of this large database {about 350 nights}. For the whole survey {and a delta-function mass distribution} the mass error should approach only about 15%, or about 6% error in slope for a power-law distribution. These results will better allow us to pinpoint the lens halo fraction, and the shape of the halo lens spatial distribution, and allow generalization/comparison of the nature of halo dark matter in spiral galaxies. In addition, we will be able to establish the baseline magnitude for about 50, 000 variable stars, as well as measure an unprecedentedly deta iled color-magnitude diagram and luminosity

  1. Image mosaic and topographic map of the moon

    USGS Publications Warehouse

    Hare, Trent M.; Hayward, Rosalyn K.; Blue, Jennifer S.; Archinal, Brent A.

    2015-01-01

    Sheet 2: This map is based on data from the Lunar Orbiter Laser Altimeter (LOLA; Smith and others, 2010), an instrument on the National Aeronautics and Space Administration (NASA) Lunar Reconnaissance Orbiter (LRO) spacecraft (Tooley and others, 2010). The image used for the base of this map represents more than 6.5 billion measurements gathered between July 2009 and July 2013, adjusted for consistency in the coordinate system described below, and then converted to lunar radii (Mazarico and others, 2012). For the Mercator portion, these measurements were converted into a digital elevation model (DEM) with a resolution of 0.015625 degrees per pixel, or 64 pixels per degree. In projection, the pixels are 473.8 m in size at the equator. For the polar portion, the LOLA elevation points were used to create a DEM at 240 meters per pixel. A shaded relief map was generated from each DEM with a sun angle of 45° from horizontal, and a sun azimuth of 270°, as measured clockwise from north with no vertical exaggeration. The DEM values were then mapped to a global color look-up table, with each color representing a range of 1 km of elevation. For this map sheet, only larger feature names are shown. For references listed above, please open the full PDF.

  2. A topographic instructive signal guides the adjustment of the auditory space map in the optic tectum.

    PubMed

    Hyde, P S; Knudsen, E I

    2001-11-01

    Maps of auditory space in the midbrain of the barn owl (Tyto alba) are calibrated by visual experience. When owls are raised wearing prismatic spectacles that displace the visual field in azimuth, the auditory receptive fields of neurons in the optic tectum shift to compensate for the optical displacement of the visual field. This shift results primarily from a shift in the tuning of tectal neurons for interaural time difference. The visually based instructive signal that guides this plasticity could be based on a topographic, point-by-point comparison between auditory and visual space maps or on a foveation-dependent visual assessment of the accuracy of auditory orienting responses. To distinguish between these two possibilities, we subjected owls to optical conditions that differed in the center of gaze and the visual periphery. A topographic signal would cause the portions of the space map representing the central and peripheral regions of visual space to adjust differently, according to the optical conditions that exist in each region. In contrast, a foveation-based signal would cause both portions of the map to adjust similarly, according to the optical conditions that exist at the center of gaze. In six of seven experiments, adaptive changes were as predicted by a topographic instructive signal. Although the results do not rule out the possible contribution of a foveation-based signal, they demonstrate that a topographic instructive signal is, indeed, involved in the calibration of the auditory space map in the barn owl optic tectum. PMID:11606646

  3. Stochastic Interaction between Neural Activity and Molecular Cues in the Formation of Topographic Maps.

    PubMed

    Owens, Melinda T; Feldheim, David A; Stryker, Michael P; Triplett, Jason W

    2015-09-23

    Topographic maps in visual processing areas maintain the spatial order of the visual world. Molecular cues and neuronal activity both play critical roles in map formation, but their interaction remains unclear. Here, we demonstrate that when molecular- and activity-dependent cues are rendered nearly equal in force, they drive topographic mapping stochastically. The functional and anatomical representation of azimuth in the superior colliculus of heterozygous Islet2-EphA3 knockin (Isl2(EphA3/+)) mice is variable: maps may be single, duplicated, or a combination of the two. This heterogeneity is not due to genetic differences, since map organizations in individual mutant animals often differ between colliculi. Disruption of spontaneous waves of retinal activity resulted in uniform map organization in Isl2(EphA3/+) mice, demonstrating that correlated spontaneous activity is required for map heterogeneity. Computational modeling replicates this heterogeneity, revealing that molecular- and activity-dependent forces interact simultaneously and stochastically during topographic map formation. PMID:26402608

  4. Topographic Mapping and Rover Localization in MER 2003 Mission Landing Sites

    NASA Astrophysics Data System (ADS)

    Li, R.; di, K.; Matthies, L.; Maimone, M.; Arvidson, R.; Crumpler, L.; Xu, F.; Wang, J.; Niu, X.; Serafy, C.; Ming, D.; Richter, L.; Marais, D.; Golombek, M.; Squyres, S.; Johnson, J.; Bell, J.; Maki, J.; Malin, M.; Parker, T.; Edwards, L.; Sims, M.; Wang, A.; Garvin, J.; Soderblom, L.

    2004-05-01

    This presentation illustrates results of topographic mapping and rover localization in Spirit and Opportunity landing sites. MOC/NA images, DIMES descent images, and surface Pancam and Navcam images are used to map regional and local topographic features of the landing sites. A new bundle adjustment method builds an image network with improved visual odometric data to supply enhance pointing data that are essential for high accuracy mapping and rover localization. Special 3D mapping products of the crater where Opportunity spacecraft landed are produced first time using rover images acquired from inside of a planetary crater. Traverse maps will show the comparison result of rover positions computed from the rover telemetry data with those from the image-based localization method. Analysis of the differences will be performed considering wheel slippage, IMU drift, and other factors. High quality topographic mapping products such as orthoimage base maps, 3D digital terrain models, and 3D interactive viewing tools are developed to support a series of mission operations and outreach activities, including long term science planning, rover path planning, geological mapping, wheel track property investigation, rock distribution estimation, crater modeling, and TV simulation scenes.

  5. Oscillatory and burst discharge across electrosensory topographic maps.

    PubMed

    Turner, R W; Plant, J R; Maler, L

    1996-10-01

    1. Three parallel maps of the distribution of tuberous electroreceptor inputs are found in the medullary electrosensory lateral line lobe (ELL) of weakly electric fish. Pyramidal cells in each map are known to respond differentially to the frequency of amplitude modulations (AMs) of external electric fields in vivo. We used an in vitro ELL slice preparation of Apteronotus leptorhynchus to compare the characteristics of spontaneously active single units across the three tuberous maps. It was our objective to determine whether spontaneous bursting activity of pyramidal cells in each map correlates with the known AM frequency selectivities of pyramidal cells in vivo. 2. Single-unit discharges were recorded from the pyramidal cell layer of the centromedial segment (CMS), centrolateral segment (CLS), and lateral segment (LS) of the ELL. Stochastic analysis of interspike intervals (ISIs) was used to identify bursting and nonbursting unit activity, and to separately analyze intra- and interburst ISIs. Four ISI patterns were identified as 1) bursting, 2) regular spiking, 3) irregular spiking, and 4) highly irregular spiking. This work focuses primarily on the characteristics of bursting units across the ELL segments. 3. Spontaneous bursting discharge was identified in all three maps (68 of 97 units), with several characteristics changing in a gradual manner across the maps. The coefficient of variation (CV) of ISIs and intraburst ISIs decreased significantly from the CMS to the LS, whereas the CV of burst periods increased significantly from the CMS to the LS. Autocorrelations and power spectral density analysis identified units discharging in an oscillatory manner with the following ratio: CMS, 75%; CLS, 4%; LS, 8%. 4. The mean period of spike bursts decreased significantly across the segments (CMS, 2.7 s; CLS, 1.2 s; LS, 1.1 s) primarily because of a shortening of mean burst duration (CMS, 1.0 s; CLS, 0.1 s; LS, 0.05 s). The average number of spikes per burst decreased

  6. Can Selforganizing Maps Accurately Predict Photometric Redshifts?

    NASA Technical Reports Server (NTRS)

    Way, Michael J.; Klose, Christian

    2012-01-01

    We present an unsupervised machine-learning approach that can be employed for estimating photometric redshifts. The proposed method is based on a vector quantization called the self-organizing-map (SOM) approach. A variety of photometrically derived input values were utilized from the Sloan Digital Sky Survey's main galaxy sample, luminous red galaxy, and quasar samples, along with the PHAT0 data set from the Photo-z Accuracy Testing project. Regression results obtained with this new approach were evaluated in terms of root-mean-square error (RMSE) to estimate the accuracy of the photometric redshift estimates. The results demonstrate competitive RMSE and outlier percentages when compared with several other popular approaches, such as artificial neural networks and Gaussian process regression. SOM RMSE results (using delta(z) = z(sub phot) - z(sub spec)) are 0.023 for the main galaxy sample, 0.027 for the luminous red galaxy sample, 0.418 for quasars, and 0.022 for PHAT0 synthetic data. The results demonstrate that there are nonunique solutions for estimating SOM RMSEs. Further research is needed in order to find more robust estimation techniques using SOMs, but the results herein are a positive indication of their capabilities when compared with other well-known methods

  7. Significance probability mapping: an aid in the topographic analysis of brain electrical activity.

    PubMed

    Duffy, F H; Bartels, P H; Burchfiel, J L

    1981-05-01

    We illustrate the application of significance probability mapping (SPM) to the analysis of topographic maps of spectral analyzed EEG and visual evoked potential (VEP) activity from patients with brain tumors, boys with dyslexia, and control subjects. When the VEP topographic plots of tumor patients were displayed as number of standard deviations from a reference mean, more subjects were correctly identified than by inspection of the underlying raw data. When topographic plots of EEG alpha activity obtained while listening to speech or music were compared by t statistic to plots of resting alpha activity, regions of cortex presumably activated by speech or music were delineated. DIfferent regions were defined in dyslexic boys and controls. We propose that SPM will prove valuable in the regional localization of normal and abnormal functions in other clinical situations. PMID:6165544

  8. Motion processing across multiple topographic maps in the electrosensory system

    PubMed Central

    Khosravi‐Hashemi, Navid; Chacron, Maurice J.

    2014-01-01

    Abstract Animals can efficiently process sensory stimuli whose attributes vary over orders of magnitude by devoting specific neural pathways to process specific features in parallel. Weakly electric fish offer an attractive model system as electrosensory pyramidal neurons responding to amplitude modulations of their self‐generated electric field are organized into three parallel maps of the body surface. While previous studies have shown that these fish use parallel pathways to process stationary stimuli, whether a similar strategy is used to process motion stimuli remains unknown to this day. We recorded from electrosensory pyramidal neurons in the weakly electric fish Apteronotus leptorhynchus across parallel maps of the body surface (centromedial, centrolateral, and lateral) in response to objects moving at velocities spanning the natural range. Contrary to previous observations made with stationary stimuli, we found that all cells responded in a similar fashion to moving objects. Indeed, all cells showed a stronger directionally nonselective response when the object moved at a larger velocity. In order to explain these results, we built a mathematical model incorporating the known antagonistic center–surround receptive field organization of these neurons. We found that this simple model could quantitatively account for our experimentally observed differences seen across E and I‐type cells across all three maps. Our results thus provide strong evidence against the hypothesis that weakly electric fish use parallel neural pathways to process motion stimuli and we discuss their implications for sensory processing in general. PMID:24760508

  9. Automated bias-compensation of rational polynomial coefficients of high resolution satellite imagery based on topographic maps

    NASA Astrophysics Data System (ADS)

    Oh, Jaehong; Lee, Changno

    2015-02-01

    As the need for efficient methods to accurately update and refine geospatial satellite image databases is increasing, we have proposed the use of 3-dimensional digital maps for the fully-automated RPCs bias compensation of high resolution satellite imagery. The basic idea is that the map features are scaled and aligned to the image features, except for the local shift, through the RPCs-based image projection, and then the shifts are automatically determined over the entire image space by template-based edge matching of the heterogeneous data set. This enables modeling of RPCs bias compensation parameters for accurate georeferencing. The map features are selected based on four suggested rules. Experiments were carried out for three Kompsat-2 images and stereo IKONOS images with 1:5000 scale Korean national topographic maps. Image matching performance is discussed with justification of the parameter selection, and the georeferencing accuracy is analyzed. The experimental results showed the automated approach can achieve one-pixel level of georeferencing accuracy, enabling economical hybrid map creation as well as large scale map updates.

  10. Short-term synaptic plasticity across topographic maps in the electrosensory system.

    PubMed

    Mileva, G R; Kozak, I J; Lewis, J E

    2016-03-24

    The early pathways underlying the active electric sense of the weakly electric fish Apteronotus leptorhynchus involve three parallel processing streams. An array of tuberous electroreceptors distributed over the skin provides inputs to the electrosensory lateral line lobe (ELL), forming the basis for three topographic maps: LS (lateral segment), CLS (centrolateral segment), and CMS (centromedial segment). In addition, each map receives topographically preserved inputs from a direct feedback pathway. How this feedback contributes to the distinct spatiotemporal filtering properties of ELL pyramidal neurons across maps is not clear. We used an in vitro approach to characterize short-term plasticity (STP) in the direct feedback synapses onto pyramidal neurons in each map. Our findings indicated that the dynamics of STP varied across maps in a manner that was consistent with the temporal filtering properties of pyramidal neurons in vivo. Using a modeling approach, we found that the STP of direct feedback synapses in CMS was best described by a simple facilitation-depression model. On the other hand, STP in LS was best described by synaptic facilitation with a use-dependent recovery rate. These results suggest that differential regulation of overlapping STP processes in feedback pathways can contribute to the functional specialization of topographic sensory maps. PMID:26791523

  11. Sperry versus Hebb: Topographic mapping in Isl2/EphA3 mutant mice

    PubMed Central

    2010-01-01

    Background In wild-type mice, axons of retinal ganglion cells establish topographically precise projection to the superior colliculus of the midbrain. This means that axons of neighboring retinal ganglion cells project to the proximal locations in the target. The precision of topographic projection is a result of combined effects of molecular labels, such as Eph receptors and ephrins, and correlated neural activity. In the Isl2/EphA3 mutant mice the expression levels of molecular labels are changed. As a result the topographic projection is rewired so that the neighborhood relationships between retinal cell axons are disrupted. Results Here we study the computational model for retinocollicular connectivity formation that combines the effects of molecular labels and correlated neural activity. We argue that the effects of correlated activity presenting themselves in the form of Hebbian learning rules can facilitate the restoration of the topographic connectivity even when the molecular labels carry conflicting instructions. This occurs because the correlations in electric activity carry information about retinal cells' origin that is independent on molecular labels. We argue therefore that partial restoration of the topographic property of the retinocollicular projection observed in Isl2/EphA3 heterozygous knockin mice may be explained by the effects of correlated neural activity. We address the maps observed in Isl2/EphA3 knockin/EphA4 knockout mice in which the levels of retinal labels are uniformly reduced. These maps can be explained by either the saturation of EphA receptor mapping leading to the relative signaling model or by the reverse signaling conveyed by ephrin-As expressed by retinal axons. Conclusion According to our model, experiments in Isl2/EphA3 knock-in mice test the interactions between effects of molecular labels and correlated activity during the development of neural connectivity. Correlated activity can partially restore topographic order even

  12. Fixed-Wing Micro Aerial Vehicle for Accurate Corridor Mapping

    NASA Astrophysics Data System (ADS)

    Rehak, M.; Skaloud, J.

    2015-08-01

    In this study we present a Micro Aerial Vehicle (MAV) equipped with precise position and attitude sensors that together with a pre-calibrated camera enables accurate corridor mapping. The design of the platform is based on widely available model components to which we integrate an open-source autopilot, customized mass-market camera and navigation sensors. We adapt the concepts of system calibration from larger mapping platforms to MAV and evaluate them practically for their achievable accuracy. We present case studies for accurate mapping without ground control points: first for a block configuration, later for a narrow corridor. We evaluate the mapping accuracy with respect to checkpoints and digital terrain model. We show that while it is possible to achieve pixel (3-5 cm) mapping accuracy in both cases, precise aerial position control is sufficient for block configuration, the precise position and attitude control is required for corridor mapping.

  13. Develop advanced nonlinear signal analysis topographical mapping system

    NASA Technical Reports Server (NTRS)

    Jong, Jen-Yi

    1993-01-01

    As reported in the monthly technical progress report for July 1993, a new signal analysis technique called instantaneous frequency correlation (IFC) for time delay estimation was developed which will be incorporated into the ATMS system. In this report, a different technique for time delay estimation called phase difference time derivative estimator (FDTDE) will be discussed. The FDTDE technique does not replace the IFC method since their application conditions are different. The IFC technique can estimate the time delay between two spectral components of two measurement signals when the center frequency of the components is constant, while the FDTDE method can provide accurate time delay estimation when the frequency of the subject component changes linearly such as during engine startup or shut-down.

  14. Unveiling topographical changes using LiDAR mapping capability: case study of Belaga in Sarawak, East-Malaysia

    NASA Astrophysics Data System (ADS)

    Ganendra, T. R.; Khan, N. M.; Razak, W. J.; Kouame, Y.; Mobarakeh, E. T.

    2016-06-01

    The use of Light Detection and Ranging (LiDAR) remote sensing technology to scan and map landscapes has proven to be one of the most popular techniques to accurately map topography. Thus, LiDAR technology is the ultimate method of unveiling the surface feature under dense vegetation, and, this paper intends to emphasize the diverse techniques that can be utilized to elucidate topographical changes over the study area, using multi-temporal airborne full waveform LiDAR datasets collected in 2012 and 2014. Full waveform LiDAR data offers access to an almost unlimited number of returns per shot, which enables the user to explore in detail topographical changes, such as vegetation growth measurement. The study also found out topography changes at the study area due to earthwork activities contributing to soil consolidation, soil erosion and runoff, requiring cautious monitoring. The implications of this study not only concurs with numerous investigations undertaken by prominent researchers to improve decision making, but also corroborates once again that investigations employing multi-temporal LiDAR data to unveil topography changes in vegetated terrains, produce more detailed and accurate results than most other remote sensing data.

  15. Geologic and topographic maps of the Kabul South 30' x 60' quadrangle, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2010-01-01

    This report consists of two map sheets, this pamphlet, and a collection of database files. Sheet 1 is the geologic map with three highly speculative cross sections, and sheet 2 is a topographic map that comprises all the support data for the geologic map. Both maps (sheets 1 and 2) are produced at 1:100,000-scale and are provided in Geospatial PDF format that preserves the georegistration and original layering. The database files include images of the topographic hillshade (shaded relief) and color-topography files used to create the topographic maps, a copy of the Landsat image, and a gray-scale basemap. Vector data from each of the layers that comprise both maps are provided in the form of Arc/INFO shapefiles. Most of the geologic interpretations and all of the topographic data were derived exclusively from images. A variety of image types were used, and each image type corresponds to a unique view of the geology. The geologic interpretations presented here are the result of comparing and contrasting between the various images and making the best uses of the strengths of each image type. A limited amount of fieldwork, in the spring of 2004 and the fall of 2006, was carried out within the quadrangle, but all the war-related dangers present in Afghanistan restricted its scope, duration, and utility. The maps that are included in this report represent works-in-progress in that they are simply intended to be the best possible product for the time available and conditions that exist during the early phases of reconstruction in Afghanistan. This report has been funded by the United States Agency for International Development (USAID) as a part of several broader programs that USAID designed to stimulate growth in the energy and mineral sectors of the Afghan economy. The main objective is to provide maps that will be used by scientists of the Afghan Ministry of Mines, the Afghanistan Geological Survey, and the Afghan Geodesy and Cartography Head Office in their efforts

  16. Geologic and Topographic Maps of the Kabul North 30' x 60' Quadrangle, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2010-01-01

    This report consists of two map sheets, this pamphlet, and a collection of database files. Sheet 1 is the geologic map with two highly speculative cross sections, and sheet 2 is a topographic map that comprises all the support data for the geologic map. Both maps (sheets 1 and 2) are produced at 1:100,000-scale and are provided in GeoPDF format that preserves the georegistration and original layering. The database files include images of the topographic hillshade (shaded relief) and color-topography files used to create the topographic maps, a copy of the Landsat image, and a gray-scale basemap. Vector data from each of the layers that comprise both maps are provided in the form of Arc/INFO shapefiles. Most of the geologic interpretations and all of the topographic data were derived exclusively from images. A variety of image types were used, and each image type corresponds to a unique view of the geology. The geologic interpretations presented here are the result of comparing and contrasting between the various images and making the best uses of the strengths of each image type. A limited amount of fieldwork, in the spring of 2004 and the fall of 2006, was carried out within the quadrangle, but all the war-related dangers present in Afghanistan restricted its scope, duration, and utility. The maps that are included in this report represent works-in-progress in that they are simply intended to be the best possible product for the time available and conditions that exist during the early phases of reconstruction in Afghanistan. This report has been funded by the United States Agency for International Development (USAID) as a part of several broader programs that USAID designed to stimulate growth in the energy and mineral sectors of the Afghan economy. The main objective is to provide maps that will be used by scientists of the Afghan Ministry of Mines, the Afghanistan Geological Survey, and the Afghan Geodesy and Cartography Head Office in their efforts to rebuild

  17. Grids in Topographic Maps Reduce Distortions in the Recall of Learned Object Locations

    PubMed Central

    Edler, Dennis; Bestgen, Anne-Kathrin; Kuchinke, Lars; Dickmann, Frank

    2014-01-01

    To date, it has been shown that cognitive map representations based on cartographic visualisations are systematically distorted. The grid is a traditional element of map graphics that has rarely been considered in research on perception-based spatial distortions. Grids do not only support the map reader in finding coordinates or locations of objects, they also provide a systematic structure for clustering visual map information (“spatial chunks”). The aim of this study was to examine whether different cartographic kinds of grids reduce spatial distortions and improve recall memory for object locations. Recall performance was measured as both the percentage of correctly recalled objects (hit rate) and the mean distance errors of correctly recalled objects (spatial accuracy). Different kinds of grids (continuous lines, dashed lines, crosses) were applied to topographic maps. These maps were also varied in their type of characteristic areas (LANDSCAPE) and different information layer compositions (DENSITY) to examine the effects of map complexity. The study involving 144 participants shows that all experimental cartographic factors (GRID, LANDSCAPE, DENSITY) improve recall performance and spatial accuracy of learned object locations. Overlaying a topographic map with a grid significantly reduces the mean distance errors of correctly recalled map objects. The paper includes a discussion of a square grid's usefulness concerning object location memory, independent of whether the grid is clearly visible (continuous or dashed lines) or only indicated by crosses. PMID:24869486

  18. Tensor SOM and tensor GTM: Nonlinear tensor analysis by topographic mappings.

    PubMed

    Iwasaki, Tohru; Furukawa, Tetsuo

    2016-05-01

    In this paper, we propose nonlinear tensor analysis methods: the tensor self-organizing map (TSOM) and the tensor generative topographic mapping (TGTM). TSOM is a straightforward extension of the self-organizing map from high-dimensional data to tensorial data, and TGTM is an extension of the generative topographic map, which provides a theoretical background for TSOM using a probabilistic generative model. These methods are useful tools for analyzing and visualizing tensorial data, especially multimodal relational data. For given n-mode relational data, TSOM and TGTM can simultaneously organize a set of n-topographic maps. Furthermore, they can be used to explore the tensorial data space by interactively visualizing the relationships between modes. We present the TSOM algorithm and a theoretical description from the viewpoint of TGTM. Various TSOM variations and visualization techniques are also described, along with some applications to real relational datasets. Additionally, we attempt to build a comprehensive description of the TSOM family by adapting various data structures. PMID:26991392

  19. Inter- versus intra-subject variance in topographic mapping of the electroencephalogram.

    PubMed

    Kohrman, M H; Sugioka, C; Huttenlocher, P R; Spire, J P

    1989-10-01

    The variability of the normal topographic EEG distribution between a quiet, eyes closed, resting state and the performance of cognitive tasks (listening to a story or music) was studied in 20 normal (10 male) right-handed college students or graduates ages 18-40 yrs. Amplitude changes in the topographic frequency distribution (2.5-7 SD) of alpha frequency band (8-13 Hz) were noted between tasks and resting state in individual subjects. When group data for the resting versus listening states were compared, no statistical differences could be demonstrated. The group variability was 50% of the power of the resting record. Repeat studies in 10 subjects demonstrated a test-retest variance of 10% of the mean individual power. The data suggest that inter-subject differences in the alpha frequency and individual topographic differences will require careful normalization for development of baseline "brain maps" to serve as a standard for investigation of disease states. PMID:2791314

  20. Does topographic normalization of landsat images improve fractional tree cover mapping in tropical mountains?

    NASA Astrophysics Data System (ADS)

    Adhikari, H.; Heiskanen, J.; Maeda, E. E.; Pellikka, P. K. E.

    2015-04-01

    Fractional tree cover (Fcover) is an important biophysical variable for measuring forest degradation and characterizing land cover. Recently, atmospherically corrected Landsat data have become available, providing opportunities for high-resolution mapping of forest attributes at global-scale. However, topographic correction is a pre-processing step that remains to be addressed. While several methods have been introduced for topographic correction, it is uncertain whether Fcover models based on vegetation indices are sensitive to topographic effects. Our objective was to assess the effect of topographic correction on the accuracy of Fcover modelling. The study area was located in the Eastern Arc Mountains of Kenya. We used C-correction as a digital elevation model (DEM) based correction method. We examined if predictive models based on normalized difference vegetation index (NDVI), reduced simple ratio (RSR) and tasseled cap indices (Brightness, Greenness and Wetness) are improved if using topographically corrected data. Furthermore, we evaluated how the results depend on the DEM by correcting images using available global DEM (ASTER GDEM, SRTM) and a regional DEM. Reference Fcover was obtained from wall-to-wall airborne LiDAR data. Landsat images corresponding to minimum and maximum sun elevation were analyzed. We observed that topographic correction could only improve models based on Brightness and had very small effect on the other models. Cosine of the solar incidence angle (cos i) derived from SRTM DEM showed stronger relationship with spectral bands than other DEMs. In conclusion, our results suggest that, in tropical mountains, predictive models based on common vegetation indices are not sensitive to topographic effects.

  1. Probabilistic topographic maps from raw, full-waveform airborne LiDAR data

    NASA Astrophysics Data System (ADS)

    Jalobeanu, A.; Gonçalves, G. R.

    2011-12-01

    The main goal of the AutoProbaDTM project is to derive new methodologies to measure the topography and terrain characteristics using the latest full-waveform airborne LiDAR technology. It includes algorithmic development, implementation, and validation over a large test area. In the long run, we wish to develop techniques that are scalable and applicable to future satellite missions such as LIST (NASA Decadal Survey), to help perform efficient and accurate large-scale mapping. One of the biggest challenges is to develop fast ways to process huge volumes of raw data without compromising the accuracy and the physical consistency of the result. Over the past decades, significant progress has been made in digital elevation model (DEM) extraction and user interaction has been much reduced, however most algorithms are still supervised. Topographic surveys currently play a central role in sensor calibration and full automation is still an unsolved problem. Moreover, very few existing methods are currently able to propose a quantitative error map with the reconstructed DEM. Traditional validation and quality control only allow to check the discrepancy between the product and a set of reference points, lacking the ability to predict the actual uncertainty related to elevations at chosen locations. We plan to provide fast and automated techniques to derive topographic maps and to compute error maps as well, based on a probabilistic approach to modeling terrains and data acquisition, solving inverse problems and handling uncertainty. Bayesian inference provides a rigorous framework for model reconstruction and error propagation, treating all quantities as random, and combining sources of information optimally. In the future, the uncertainty maps shall help scientists put error bars on quantities derived from the models. In June 2011, 200 km2 of data were acquired (100 GB of binary files, half a billion waveforms) in central Portugal, over an area of geomorphological and

  2. Radar Interferometer for Topographic Mapping of Glaciers and Ice Sheets

    NASA Technical Reports Server (NTRS)

    Moller, Delwyn K.; Sadowy, Gregory A.; Rignot, Eric J.; Madsen, Soren N.

    2007-01-01

    A report discusses Ka-band (35-GHz) radar for mapping the surface topography of glaciers and ice sheets at high spatial resolution and high vertical accuracy, independent of cloud cover, with a swath-width of 70 km. The system is a single- pass, single-platform interferometric synthetic aperture radar (InSAR) with an 8-mm wavelength, which minimizes snow penetration while remaining relatively impervious to atmospheric attenuation. As exhibited by the lower frequency SRTM (Shuttle Radar Topography Mission) AirSAR and GeoSAR systems, an InSAR measures topography using two antennas separated by a baseline in the cross-track direction, to view the same region on the ground. The interferometric combination of data received allows the system to resolve the pathlength difference from the illuminated area to the antennas to a fraction of a wavelength. From the interferometric phase, the height of the target area can be estimated. This means an InSAR system is capable of providing not only the position of each image point in along-track and slant range as with a traditional SAR but also the height of that point through interferometry. Although the evolution of InSAR to a millimeter-wave center frequency maximizes the interferometric accuracy from a given baseline length, the high frequency also creates a fundamental problem of swath coverage versus signal-to-noise ratio. While the length of SAR antennas is typically fixed by mass and stowage or deployment constraints, the width is constrained by the desired illuminated swath width. As the across-track beam width which sets the swath size is proportional to the wavelength, a fixed swath size equates to a smaller antenna as the frequency is increased. This loss of antenna size reduces the two-way antenna gain to the second power, drastically reducing the signal-to-noise ratio of the SAR system. This fundamental constraint of high-frequency SAR systems is addressed by applying digital beam-forming (DBF) techniques to

  3. Techniques and applications of SAR interferometry for ERS-1: Topographic mapping, change detection, and slope measurement

    NASA Technical Reports Server (NTRS)

    Werner, Charles L.; Hensley, Scott; Goldstein, Richard M.; Rosen, Paul A.; Zebker, Howard A.

    1993-01-01

    SAR (Synthetic Aperture Radar) interferometry allows the measurement of high resolution topography of terrain from repeat orbit SAR data sets obtained by the ERS-1 AMI (Active Microwave Instrument). The system parameters which affect the accuracy of the topographic maps are errors in determination of the interferometric baseline, non parallel orbit tracks, decorrelation caused by baseline length, thermal noise, and surface change. Surface change can be observed in the interferograms either through decorrelation of the interferometric phase, or coherent phase shifts caused by locally uniform surface displacements. Phase gradient maps can be derived directly from the complex interferograms and can be transformed into surface slopes mapped onto a geometrically corrected grid.

  4. A fast approach to generate large-scale topographic maps based on new Chinese vehicle-borne Lidar system

    NASA Astrophysics Data System (ADS)

    Youmei, Han; Bogang, Yang

    2014-03-01

    Large -scale topographic maps are important basic information for city and regional planning and management. Traditional large- scale mapping methods are mostly based on artificial mapping and photogrammetry. The traditional mapping method is inefficient and limited by the environments. While the photogrammetry methods(such as low-altitude aerial mapping) is an economical and effective way to map wide and regulate range of large scale topographic map but doesn't work well in the small area due to the high cost of manpower and resources. Recent years, the vehicle-borne LIDAR technology has a rapid development, and its application in surveying and mapping is becoming a new topic. The main objective of this investigation is to explore the potential of vehicle-borne LIDAR technology to be used to fast mapping large scale topographic maps based on new Chinese vehicle-borne LIDAR system. It studied how to use the new Chinese vehicle-borne LIDAR system measurement technology to map large scale topographic maps. After the field data capture, it can be mapped in the office based on the LIDAR data (point cloud) by software which programmed by ourselves. In addition, the detailed process and accuracy analysis were proposed by an actual case. The result show that this new technology provides a new fast method to generate large scale topographic maps, which is high efficient and accuracy compared to traditional methods.

  5. Converting Topographic Maps into Digital Form to Aid in Archeological Research in the Peten, Guatemala

    NASA Technical Reports Server (NTRS)

    Aldrich, Serena R.

    1999-01-01

    The purpose of my project was to convert a topographical map into digital form so that the data can be manipulated and easily accessed in the field. With the data in this particular format, Dr. Sever and his colleagues can highlight the specific features of the landscape that they require for their research of the ancient Mayan civilization. Digital elevation models (DEMs) can also be created from the digitized contour features adding another dimension to their research.

  6. EMPLOYING TOPOGRAPHICAL HEIGHT MAP IN COLONIC POLYP MEASUREMENT AND FALSE POSITIVE REDUCTION

    PubMed Central

    Yao, Jianhua; Li, Jiang; Summers, Ronald M.

    2008-01-01

    CT Colonography (CTC) is an emerging minimally invasive technique for screening and diagnosing colon cancers. Computer Aided Detection (CAD) techniques can increase sensitivity and reduce false positives. Inspired by the way radiologists detect polyps via 3D virtual fly-through in CTC, we borrowed the idea from geographic information systems to employ topographical height map in colonic polyp measurement and false positive reduction. After a curvature based filtering and a 3D CT feature classifier, a height map is computed for each detection using a ray-casting algorithm. We design a concentric index to characterize the concentric pattern in polyp height map based on the fact that polyps are protrusions from the colon wall and round in shape. The height map is optimized through a multi-scale spiral spherical search to maximize the concentric index. We derive several topographic features from the map and compute texture features based on wavelet decomposition. We then send the features to a committee of support vector machines for classification. We have trained our method on 394 patients (71 polyps) and tested it on 792 patients (226 polyps). Results showed that we can achieve 95% sensitivity at 2.4 false positives per patient and the height map features can reduce false positives by more than 50%. We compute the polyp height and width measurements and correlate them with manual measurements. The Pearson correlations are 0.74 (p=0.11) and 0.75 (p=0.17) for height and width, respectively. PMID:19578483

  7. Determination of Important Topographic Factors for Landslide Mapping Analysis Using MLP Network

    PubMed Central

    Alkhasawneh, Mutasem Sh.; Ngah, Umi Kalthum; Mat Isa, Nor Ashidi; Al-batah, Mohammad Subhi

    2013-01-01

    Landslide is one of the natural disasters that occur in Malaysia. Topographic factors such as elevation, slope angle, slope aspect, general curvature, plan curvature, and profile curvature are considered as the main causes of landslides. In order to determine the dominant topographic factors in landslide mapping analysis, a study was conducted and presented in this paper. There are three main stages involved in this study. The first stage is the extraction of extra topographic factors. Previous landslide studies had identified mainly six topographic factors. Seven new additional factors have been proposed in this study. They are longitude curvature, tangential curvature, cross section curvature, surface area, diagonal line length, surface roughness, and rugosity. The second stage is the specification of the weight of each factor using two methods. The methods are multilayer perceptron (MLP) network classification accuracy and Zhou's algorithm. At the third stage, the factors with higher weights were used to improve the MLP performance. Out of the thirteen factors, eight factors were considered as important factors, which are surface area, longitude curvature, diagonal length, slope angle, elevation, slope aspect, rugosity, and profile curvature. The classification accuracy of multilayer perceptron neural network has increased by 3% after the elimination of five less important factors. PMID:24453846

  8. Lunar Topographic Mapping Using a New High Resolution Mode for the GSSR Radar

    NASA Technical Reports Server (NTRS)

    Hensley, Scott; Gurrola, Eric; Slade, Martin; Quirk, Kevin; Srinivasan, Meera; Lee, Clement; Yun, Sang-Ho; Jao, Joseph; Wilson, Barbara; De Jong, Eric; Marechal, Nick; Weintraub, Lawrence; Dickinson, Richard; Bloom, Ronald; Karamyan, Grant; Lilje, Anneliese; Harcke, Leif

    2010-01-01

    Mapping the Moon's topography using Earth based radar interferometric measurements by the Goldstone Solar System Radar (GSSR) has been done several times since the mid 1990s. In 2008 we reported at this conference the generation of lunar topographic maps having approximately 4 m height accuracy at a horizontal posting of 40 m. Since then GSSR radar has been improved to allow 40 MHz bandwidth imaging and consequently obtained images and interferograms with a resolution of about 4 m in range by 5 m in azimuth. The long synthetic aperture times of approximately 90 minutes in duration necessitated a migration from range/Doppler image formation techniques to spotlight mode processing and autofocusing methods. The improved resolution imagery should permit the generation of topographic maps with a factor of two better spatial resolution with about same height accuracy. Coupled the with the recent availability of new lidar topography maps of the lunar surface made by orbiting satellites of Japan and the United States the geodetic control of the radar generated maps products can be improved dramatically. This paper will discuss the hardware and software improvements made to the GSSR and present some of the new high resolution products.

  9. Analysis of Radar and Optical Space Borne Data for Large Scale Topographical Mapping

    NASA Astrophysics Data System (ADS)

    Tampubolon, W.; Reinhardt, W.

    2015-03-01

    Normally, in order to provide high resolution 3 Dimension (3D) geospatial data, large scale topographical mapping needs input from conventional airborne campaigns which are in Indonesia bureaucratically complicated especially during legal administration procedures i.e. security clearance from military/defense ministry. This often causes additional time delays besides technical constraints such as weather and limited aircraft availability for airborne campaigns. Of course the geospatial data quality is an important issue for many applications. The increasing demand of geospatial data nowadays consequently requires high resolution datasets as well as a sufficient level of accuracy. Therefore an integration of different technologies is required in many cases to gain the expected result especially in the context of disaster preparedness and emergency response. Another important issue in this context is the fast delivery of relevant data which is expressed by the term "Rapid Mapping". In this paper we present first results of an on-going research to integrate different data sources like space borne radar and optical platforms. Initially the orthorectification of Very High Resolution Satellite (VHRS) imagery i.e. SPOT-6 has been done as a continuous process to the DEM generation using TerraSAR-X/TanDEM-X data. The role of Ground Control Points (GCPs) from GNSS surveys is mandatory in order to fulfil geometrical accuracy. In addition, this research aims on providing suitable processing algorithm of space borne data for large scale topographical mapping as described in section 3.2. Recently, radar space borne data has been used for the medium scale topographical mapping e.g. for 1:50.000 map scale in Indonesian territories. The goal of this on-going research is to increase the accuracy of remote sensing data by different activities, e.g. the integration of different data sources (optical and radar) or the usage of the GCPs in both, the optical and the radar satellite data

  10. Modeling and mapping temperature and precipitation climate data in Greece using topographical and geographical parameters

    NASA Astrophysics Data System (ADS)

    Feidas, Haralambos; Karagiannidis, Athanasios; Keppas, Stavros; Vaitis, Michail; Kontos, Themistoklis; Zanis, Prodromos; Melas, Dimitrios; Anadranistakis, Emmanouil

    2014-10-01

    This study presents a methodology for modeling and mapping the seasonal and annual air temperature and precipitation climate normals over Greece using several topographical and geographical parameters. Data series of air temperature and precipitation from 84 weather stations distributed evenly over Greece are used along with a set of topographical and geographical parameters extracted with Geographic Information System methods from a digital elevation model (DEM). Normalized difference vegetation index (NDVI) obtained from MODIS Aqua satellite data is also used as a geographical parameter. First, the relation of the two climate elements to the topographical and geographical parameters was investigated based on the Pearson's correlation coefficient to identify the parameters that mostly affect the spatial variability of air temperature and precipitation over Greece. Then a backward stepwise multiple regression was applied to add topographical and geographical parameters as independent variables into a regression equation and develop linear estimation models for both climate parameters. These models are subjected to residual correction using different local interpolation methods, in an attempt to refine the estimated values. The validity of these models is checked through cross-validation error statistics against an independent test subset of station data. The topographical and geographical parameters used as independent variables in the multiple regression models are mostly those found to be strongly correlated with both climatic variables. Models perform best for annual and spring temperatures and effectively for winter and autumn temperatures. Summer temperature spatial variability is rather poorly simulated by the multiple regression model. On the contrary, best performance is obtained for summer and autumn precipitation while the multiple regression model is not able to simulate effectively the spatial distribution of spring precipitation. Results revealed also

  11. Topographic Map of Chryse Planitia with Location of Possible Buried Basin

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This topographic map, based on data from the Mars Orbiter Laser Altimeter, shows the ground track of the 1,892nd and the 1,903rd orbits of Mars Express and the arc structures detected by that orbiter's Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS). The arc structures are interpreted to be part of a buried impact basin about 250 kilometers (155 miles) in diameter.

    The topographic relief represented in the image is 1 kilometer (0.6 mile), from low (purple) to high (red). The projected arcs are shown in red for orbit 1892 and white for orbit 1903. There is no obvious feature in the surface topography that corresponds to the buried feature identified with MARSIS data.

    NASA and the Italian Space Agency jointly funded the MARSIS instrument on the European Space Agency's Mars Express orbiter. The Mars Orbiter Laser Altimeter is an instrument on NASA's Mars Global Surveyor orbiter.

  12. Accurate mapping of forest types using dense seasonal Landsat time-series

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaolin; Liu, Desheng

    2014-10-01

    An accurate map of forest types is important for proper usage and management of forestry resources. Medium resolution satellite images (e.g., Landsat) have been widely used for forest type mapping because they are able to cover large areas more efficiently than the traditional forest inventory. However, the results of a detailed forest type classification based on these images are still not satisfactory. To improve forest mapping accuracy, this study proposed an operational method to get detailed forest types from dense Landsat time-series incorporating with or without topographic information provided by DEM. This method integrated a feature selection and a training-sample-adding procedure into a hierarchical classification framework. The proposed method has been tested in Vinton County of southeastern Ohio. The detailed forest types include pine forest, oak forest, and mixed-mesophytic forest. The proposed method was trained and validated using ground samples from field plots. The three forest types were classified with an overall accuracy of 90.52% using dense Landsat time-series, while topographic information can only slightly improve the accuracy to 92.63%. Moreover, the comparison between results of using Landsat time-series and a single image reveals that time-series data can largely improve the accuracy of forest type mapping, indicating the importance of phenological information contained in multi-seasonal images for discriminating different forest types. Thanks to zero cost of all input remotely sensed datasets and ease of implementation, this approach has the potential to be applied to map forest types at regional or global scales.

  13. Generative Topographic Mapping (GTM): Universal Tool for Data Visualization, Structure-Activity Modeling and Dataset Comparison.

    PubMed

    Kireeva, N; Baskin, I I; Gaspar, H A; Horvath, D; Marcou, G; Varnek, A

    2012-04-01

    Here, the utility of Generative Topographic Maps (GTM) for data visualization, structure-activity modeling and database comparison is evaluated, on hand of subsets of the Database of Useful Decoys (DUD). Unlike other popular dimensionality reduction approaches like Principal Component Analysis, Sammon Mapping or Self-Organizing Maps, the great advantage of GTMs is providing data probability distribution functions (PDF), both in the high-dimensional space defined by molecular descriptors and in 2D latent space. PDFs for the molecules of different activity classes were successfully used to build classification models in the framework of the Bayesian approach. Because PDFs are represented by a mixture of Gaussian functions, the Bhattacharyya kernel has been proposed as a measure of the overlap of datasets, which leads to an elegant method of global comparison of chemical libraries. PMID:27477099

  14. Topographic mapping data semantics through data conversion and enhancement: Chapter 7

    USGS Publications Warehouse

    Varanka, Dalia; Carter, Jonathan; Usery, E. Lynn; Shoberg, Thomas

    2011-01-01

    This paper presents research on the semantics of topographic data for triples and ontologies to blend the capabilities of the Semantic Web and The National Map of the U.S. Geological Survey. Automated conversion of relational topographic data of several geographic sample areas to the triple data model standard resulted in relatively poor semantic associations. Further research employed vocabularies of feature type and spatial relation terms. A user interface was designed to model the capture of non-standard terms relevant to public users and to map those terms to existing data models of The National Map through the use of ontology. Server access for the study area triple stores was made publicly available, illustrating how the development of linked data may transform institutional policies to open government data resources to the public. This paper presents these data conversion and research techniques that were tested as open linked data concepts leveraged through a user-centered interface and open USGS server access to the public.

  15. Current State of Topographic Mapping of Ganymede: Squeezing the Most from JUICE

    NASA Astrophysics Data System (ADS)

    Schenk, P.; McKinnon, W. B.; Singer, K. N.; Moore, J. M.

    2014-12-01

    JUICE, ESA's planned Ganymede orbiter, and NASA's proposed Europa Clipper, won't arrive for some time, and many issues concerning Ganymede's geologic history and evolution remain. Topographic mapping will be a key component of JUICE orbital and Clipper flyby mapping and an understanding of Ganymede topography can also help guide instrument development. Topographic data for Ganymede are based almost entirely on Voyager and Galileo image analysis and are sparse. No more than 20% of the surface (which exceeds that of Mercury in area in total) is presently mappable. Both stereo (3D) and shape-from-shading (PC) are both possible (and nearly all possible DEM combinations have now been constructed). Unlike Europa, only an handful of sites are mappable using both techniques: these being mostly over the South Polar region with Voyager 2. Without stereo control, PC topography, while very useful, must be interpreted with caution. Only a handful of targeted stereo mosaics were possible from Galileo, but serendipitous Voyager-Galileo stereo greatly expands this data set. Topographic data allow determinations of RMS slope values for each terrain type, but currently only at length scales >100 m. Topographic amplitude can also be determined. Geologic units for which we have limited DEM data include: furrows, grooves, smooth and subdued grooved terrains, calderas, pit and dome craters, penepalimpsests, and palimpsests. Key science questions that can be guided by even the limited available topography include: relative elevations of smooth, grooved and dark terrains and the role of volcanic vs. tectonic resurfacing; relief of ancient degraded impact craters and the role of density and heat variations; density anomalies within or beneath the ice shell; the severity and history of thermal relaxation globally and the associated heat pulse. Here we focus on the issue of relaxation, where topographic evidence indicates that thermal relaxation reached a peak associated with bright terrain

  16. Topographic Map of Quadrangle 3568, Polekhomri (503) and Charikar (504) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  17. Topographic Map of Quadrangle 3466, Lal-Sarjangal (507) and Bamyan (508) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  18. Topographic Map of Quadrangle 3366, Gizab (513) and Nawer (514) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  19. Topographic Map of Quadrangle 3670, Jam-Kashem (223) and Zebak (224) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  20. Creation of next generation U.S. Geological Survey topographic maps

    USGS Publications Warehouse

    Craun, Kari J.

    2010-01-01

    The U.S. Geological Survey (USGS) is 2 years into a 3-year cycle to create new digital topographic map products for the conterminous United States from data acquired and maintained as part of The National Map databases. These products are in the traditional, USGS topographic quadrangle, 7.5-minute (latitude and longitude) cell format. The 3-year cycle was conceived to follow the acquisition of National Aerial Imagery Program (NAIP) orthorectified imagery, a key layer in the new product. In fiscal year (FY) 2009 (ending September 30, 2009), the first year of the 3-year cycle, the USGS produced 13,200 products. These initial products of the “Digital MapBeta” series had limited feature content, including only the NAIP image, some roads, geographic names, and grid and collar information. The products were created in layered georegistered Portable Document Format (PDF) files, allowing users with freely available Adobe® Reader® software to view, print, and perform simple Geographic Information System-like functions. In FY 2010 (ending September 30, 2010), the USGS produced 20,380 products. These products of the “US Topo” series added hydrography (surface water features), contours, and some boundaries. In FY 2011 (ending September 30, 2011), the USGS will complete the initial coverage with US Topo products and will add additional feature content to the maps. The design, development, and production associated with the US Topo products provide management and technical challenges for the USGS and its public and private sector partners. One challenge is the acquisition and maintenance of nationally consistent base map data from multiple sources. Another is the use of these data to create a consistent, current series of cartographic products that can be used by the broad spectrum of traditional topographic map users. Although the USGS and its partners have overcome many of these challenges, many, such as establishing and funding a sustainable base data

  1. High-resolution multibeam mapping and submersible surveys of topographic features in the northwestern Gulf of Mexico

    USGS Publications Warehouse

    Hickerson, E.L.; Schmahl, G.P.; Weaver, D.C.; Gardner, J.V.

    2003-01-01

    The Flower Garden Banks National Marine Sanctuary (FGBNMS) and the USGS Pacific Seafloor Mapping Project mapped about 2000 km2 of the northwestern Gulf of Mexico continental shelf during June 2002, using a Kongsberg Simrad EM1000 multibeam echosounder. Mapping focused on select topographic highs thave hae been idetnnfied as biological features warranting protection from oil and gas activities by the Minerals Management Service (MMS). The base maps will be used for all future ROV and submersible missions.

  2. A VS30 map for California with geologic and topographic constraints

    USGS Publications Warehouse

    Thompson, Eric; Wald, David J.; Worden, Charles

    2014-01-01

    For many earthquake engineering applications, site response is estimated through empirical correlations with the time‐averaged shear‐wave velocity to 30 m depth (VS30). These applications therefore depend on the availability of either site‐specific VS30 measurements or VS30 maps at local, regional, and global scales. Because VS30 measurements are sparse, a proxy frequently is needed to estimate VS30 at unsampled locations. We present a new VS30 map for California, which accounts for observational constraints from multiple sources and spatial scales, such as geology, topography, and site‐specific VS30measurements. We apply the geostatistical approach of regression kriging (RK) to combine these constraints for predicting VS30. For the VS30 trend, we start with geology‐based VS30 values and identify two distinct trends between topographic gradient and the residuals from the geology VS30 model. One trend applies to deep and fine Quaternary alluvium, whereas the second trend is slightly stronger and applies to Pleistocene sedimentary units. The RK framework ensures that the resulting map of California is locally refined to reflect the rapidly expanding database of VS30 measurements throughout California. We compare the accuracy of the new mapping method to a previously developed map of VS30 for California. We also illustrate the sensitivity of ground motions to the new VS30 map by comparing real and scenario ShakeMaps with VS30 values from our new map to those for existingVS30 maps.

  3. Integrating historical topographic maps and SRTM data to derive the bathymetry of a tropical reservoir

    NASA Astrophysics Data System (ADS)

    Alcântara, Enner; Novo, Evlyn; Stech, José; Assireu, Arcilan; Nascimento, Renata; Lorenzzetti, João; Souza, Arley

    2010-08-01

    SummaryThis paper proposes a fast and inexpensive method for estimating the bathymetry of hydroelectric reservoirs. Brazil has more than 30 large hydroelectric reservoirs with a combined volume exceeding one billion cubic meters. The hydroelectric sector is responsible for 97% of the energy production in Brazil and is the largest hydroelectric park in the world. Among the variables affecting the environmental impacts of reservoirs, depth plays a major role because it influences the aquatic system hydrodynamics. Reservoir depth distribution (i.e., the bathymetry) is also a fundamental factor controlling the physical-chemical and biological properties of the system. However, the acquisition of bathymetric information for the large reservoirs in Brazil is not a simple task because: (1) most of the topographic maps available in the area of the lake have a very small scale (1:100,000 and smaller), (2) larger charts are the property of the hydropower companies and are classified, and (3) the size of the reservoirs prevent the use of bathymetric surveys. The proposed method of integrating historical and Shuttle Radar Topography Mission (SRTM) topographic data allowed for the estimation of the bathymetry of the Itumbiara reservoir with R2 = 0.98 ( n = 100, ρ = 0.00) and RMSE = 3.78 m. For researchers who need a rapid and simple method to develop bathymetric maps of hydroelectric reservoirs, the proposed method can provide a simple and fast alternative to more data intensive methods.

  4. Space based topographic mapping experiment using Seasat synthetic aperture radar and LANDSAT 3 return beam vidicon imagery

    NASA Technical Reports Server (NTRS)

    Mader, G. L.

    1981-01-01

    A technique for producing topographic information is described which is based on same side/same time viewing using a dissimilar combination of radar imagery and photographic images. Common geographic areas viewed from similar space reference locations produce scene elevation displacements in opposite direction and proper use of this characteristic can yield the perspective information necessary for determination of base to height ratios. These base to height ratios can in turn be used to produce a topographic map. A test area covering the Harrisburg, Pennsylvania region was observed by synthetic aperture radar on the Seasat satellite and by return beam vidicon on by the LANDSAT - 3 satellite. The techniques developed for the scaling re-orientation and common registration of the two images are presented along with the topographic determination data. Topographic determination based exclusively on the images content is compared to the map information which is used as a performance calibration base.

  5. Bioclimatic and vegetation mapping of a topographically complex oceanic island applying different interpolation techniques

    NASA Astrophysics Data System (ADS)

    Garzón-Machado, Víctor; Otto, Rüdiger; del Arco Aguilar, Marcelino José

    2014-07-01

    Different spatial interpolation techniques have been applied to construct objective bioclimatic maps of La Palma, Canary Islands. Interpolation of climatic data on this topographically complex island with strong elevation and climatic gradients represents a challenge. Furthermore, meteorological stations are not evenly distributed over the island, with few stations at high elevations. We carried out spatial interpolations of the compensated thermicity index (Itc) and the annual ombrothermic Index (Io), in order to obtain appropriate bioclimatic maps by using automatic interpolation procedures, and to establish their relation to potential vegetation units for constructing a climatophilous potential natural vegetation map (CPNV). For this purpose, we used five interpolation techniques implemented in a GIS: inverse distance weighting (IDW), ordinary kriging (OK), ordinary cokriging (OCK), multiple linear regression (MLR) and MLR followed by ordinary kriging of the regression residuals. Two topographic variables (elevation and aspect), derived from a high-resolution digital elevation model (DEM), were included in OCK and MLR. The accuracy of the interpolation techniques was examined by the results of the error statistics of test data derived from comparison of the predicted and measured values. Best results for both bioclimatic indices were obtained with the MLR method with interpolation of the residuals showing the highest R 2 of the regression between observed and predicted values and lowest values of root mean square errors. MLR with correction of interpolated residuals is an attractive interpolation method for bioclimatic mapping on this oceanic island since it permits one to fully account for easily available geographic information but also takes into account local variation of climatic data.

  6. Bioclimatic and vegetation mapping of a topographically complex oceanic island applying different interpolation techniques.

    PubMed

    Garzón-Machado, Víctor; Otto, Rüdiger; del Arco Aguilar, Marcelino José

    2014-07-01

    Different spatial interpolation techniques have been applied to construct objective bioclimatic maps of La Palma, Canary Islands. Interpolation of climatic data on this topographically complex island with strong elevation and climatic gradients represents a challenge. Furthermore, meteorological stations are not evenly distributed over the island, with few stations at high elevations. We carried out spatial interpolations of the compensated thermicity index (Itc) and the annual ombrothermic Index (Io), in order to obtain appropriate bioclimatic maps by using automatic interpolation procedures, and to establish their relation to potential vegetation units for constructing a climatophilous potential natural vegetation map (CPNV). For this purpose, we used five interpolation techniques implemented in a GIS: inverse distance weighting (IDW), ordinary kriging (OK), ordinary cokriging (OCK), multiple linear regression (MLR) and MLR followed by ordinary kriging of the regression residuals. Two topographic variables (elevation and aspect), derived from a high-resolution digital elevation model (DEM), were included in OCK and MLR. The accuracy of the interpolation techniques was examined by the results of the error statistics of test data derived from comparison of the predicted and measured values. Best results for both bioclimatic indices were obtained with the MLR method with interpolation of the residuals showing the highest R2 of the regression between observed and predicted values and lowest values of root mean square errors. MLR with correction of interpolated residuals is an attractive interpolation method for bioclimatic mapping on this oceanic island since it permits one to fully account for easily available geographic information but also takes into account local variation of climatic data. PMID:23686111

  7. The Use of Multiple Data Sources in the Process of Topographic Maps Updating

    NASA Astrophysics Data System (ADS)

    Cantemir, A.; Visan, A.; Parvulescu, N.; Dogaru, M.

    2016-06-01

    The methods used in the process of updating maps have evolved and become more complex, especially upon the development of the digital technology. At the same time, the development of technology has led to an abundance of available data that can be used in the updating process. The data sources came in a great variety of forms and formats from different acquisition sensors. Satellite images provided by certain satellite missions are now available on space agencies portals. Images stored in archives of satellite missions such us Sentinel, Landsat and other can be downloaded free of charge.The main advantages are represented by the large coverage area and rather good spatial resolution that enables the use of these images for the map updating at an appropriate scale. In our study we focused our research of these images on 1: 50.000 scale map. DEM that are globally available could represent an appropriate input for watershed delineation and stream network generation, that can be used as support for hydrography thematic layer update. If, in addition to remote sensing aerial photogrametry and LiDAR data are ussed, the accuracy of data sources is enhanced. Ortophotoimages and Digital Terrain Models are the main products that can be used for feature extraction and update. On the other side, the use of georeferenced analogical basemaps represent a significant addition to the process. Concerning the thematic maps, the classic representation of the terrain by contour lines derived from DTM, remains the best method of surfacing the earth on a map, nevertheless the correlation with other layers such as Hidrography are mandatory. In the context of the current national coverage of the Digital Terrain Model, one of the main concerns of the National Center of Cartography, through the Cartography and Photogrammetry Department, is represented by the exploitation of the available data in order to update the layers of the Topographic Reference Map 1:5000, known as TOPRO5 and at the

  8. The Status of Topographic Mapping in the World a Unggim-Isprs Project 2012-2015

    NASA Astrophysics Data System (ADS)

    Konecny, G.; Breitkopf, U.; Radtke, A.

    2016-06-01

    In December 2011, UNGGIM initiated a cooperative project with ISPRS to resume the former UN Secretariat studies on the status of topographic mapping in the world, conducted between 1968 and 1986. After the design of a questionnaire with 27 questions, the UNGGIM Secretariat sent the questionnaires to the UN member states. 115 replies were received from the 193 member states and regions thereof. Regarding the global data coverage and age, the UN questionnaire survey was supplemented by data from the Eastview database. For each of the 27 questions, an interactive viewer was programmed permitting the analysis of the results. The authoritative data coverage at the various scale ranges has greatly increased between 1986 and 2012. Now, a 30 % 1 : 25 000 map data coverage and a 75 % 1 : 50 000 map data coverage has been completed. Nevertheless, there is still an updating problem, as data for some countries is 10 to 30 years old. Private Industry, with Google, Microsoft and Navigation system providers, have undertaken huge efforts to supplement authoritative mapping. For critical areas on the globe, MGCP committed to military mapping at 1 : 50 000. ISPRS has decided to make such surveys a sustainable issue by establishing a working group.

  9. Demonstration of volumetric analysis using the topographical mapping system at Hanford

    SciTech Connect

    Armstrong, G.A.; Burks, B.L.; Carteret, B.A.; Pardini, A.F.; Samuel, T.J.

    1997-07-01

    During the spring of 1997, the Topographical Mapping System (TMS) for hazardous and radiological environments was used to perform volumetric measurements of simulated waste in the cold test cell in the Fuel Materials and Examination Facility at the Hanford site. The TMS was used to measure the volume of five simulated waste mounds. Custom software designed by Oak Ridge National Laboratory was used to calculate the volume of waste from the surface maps supplied by the TMS. The results of the measurements were analyzed using the Interactive Computer-Enhanced Remote-Viewing System (ICERVS) and were documented. Development of the TMS and ICERVS was initiated by the US Department of Energy (DOE) for the purpose of characterization and remediation of underground storage tanks (USTs) at DOE sites across the country. DOE required a three-dimensional TMS suitable for use in hazardous and radiological environments. The intended application is the mapping of the interior of USTs as part of DOE`s waste characterization and remediation efforts to obtain baseline data on the content of storage tank interiors as well as on changes in the tank contents and levels brought about by waste remediation steps. Initially targeted for deployment at the Hanford site, the TMS was designed to be a self-contained, compact, and reconfigurable system that is capable of providing rapid, variable-resolution mapping information in poorly characterized workspaces with a minimum of operator intervention. An appendix contains the source code for calculating the volume from two surface maps.

  10. Photon-counting lidars for contiguous high resolution topographic mapping of planets and moons

    NASA Astrophysics Data System (ADS)

    Degnan, John J.

    2007-08-01

    Planetary scientists have long expressed interest in obtaining globally contiguous, high resolution (few meter horizontal, decimeter vertical) 3D topographic maps of planets and moons. For example, the goal of NASA's LIST mission, scheduled for launch in the 2016-2020 time frame, is a globally contiguous, 5 meter resolution, topographic map of the Earth. Unfortunately, achieving such a capability through a simple scaling of the laser power and/or telescope aperture from prior art NASA laser altimeters (e.g. MOLA, GLAS, and MLA) is not practical. This is especially true of laser altimeters destined for orbit about distant planets or moons where instrument mass and prime power usage is severely constrained. Photon counting receivers permit each range measurement to be made with a single received photon, even in daylight, and the surface sampling rate of an orbiting altimeter can be increased by three to four orders of magnitude by emitting the available laser photons in a high frequency train of low energy pulses instead of a low frequency train of high energy pulses typical of past spaceborne lidars. The feasibility of the photon-counting approach in the presence of a strong solar background was first successfully demonstrated from a high altitude aircraft under NASA's Instrument Incubator Program in 2001. Sigma Space Corporation has subsequently developed a second generation of scanning 3D imaging and polarimetric lidars for use in small aircraft and Unmanned Aerial Vehicles (UAV's). Future space applications include: (1) decimeter vertical resolution topographic mapping of extraterrestrial terrain from orbiters, balloons, or other aerial vehicles for determining safe landing sites; (2) monitoring the terrain in real time and increasingly higher resolution during spacecraft descent; or (3) for truly contiguous few meter resolution imaging of planetary terrain on a global scale from orbit. Targets of particular interest to NASA are the Earth, Moon, Mars, the Jovian

  11. Concurrent and Accurate Short Read Mapping on Multicore Processors.

    PubMed

    Martínez, Héctor; Tárraga, Joaquín; Medina, Ignacio; Barrachina, Sergio; Castillo, Maribel; Dopazo, Joaquín; Quintana-Ortí, Enrique S

    2015-01-01

    We introduce a parallel aligner with a work-flow organization for fast and accurate mapping of RNA sequences on servers equipped with multicore processors. Our software, HPG Aligner SA (HPG Aligner SA is an open-source application. The software is available at http://www.opencb.org, exploits a suffix array to rapidly map a large fraction of the RNA fragments (reads), as well as leverages the accuracy of the Smith-Waterman algorithm to deal with conflictive reads. The aligner is enhanced with a careful strategy to detect splice junctions based on an adaptive division of RNA reads into small segments (or seeds), which are then mapped onto a number of candidate alignment locations, providing crucial information for the successful alignment of the complete reads. The experimental results on a platform with Intel multicore technology report the parallel performance of HPG Aligner SA, on RNA reads of 100-400 nucleotides, which excels in execution time/sensitivity to state-of-the-art aligners such as TopHat 2+Bowtie 2, MapSplice, and STAR. PMID:26451814

  12. Global Topographic Mapping Of Saturn's Midsize Icy Satellites: System-wide Thermal And Impact Effects

    NASA Astrophysics Data System (ADS)

    Schenk, Paul M.

    2010-10-01

    Cassini stereo coverage of Saturn's 6 largest midsized icy satellites has been used to produce the first global topographic maps of major icy bodies. All except Iapetus have dynamic topography of -5 to +5 km (excepting the largest basins). Apparently all except Iapetus have been topographically reset by global heating events capable of erasing or preventing the 10's of kilometers of regional relief observed on that outer moon. In contrast to Tethys, Dione features no deep large basins and exhibits lower relief generally, and extensive crater relaxation specifically. Apparently Dione remained hot even longer than Tethys, despite geologic and topographic evidence for smooth volcanic-style plains and tectonic disruption on both satellites. No deep basins are evident on Rhea either. On Rhea, the leading side features a generally much smoother texture at length-scales of 100 km than does the (faulted) trailing hemisphere, suggesting that the leading hemisphere also experienced more pervasive heating than the trailing. On Mimas, an irregular region near the antipode to Herschel exhibits lower crater depths than elsewhere, a possible signature of seismic focusing of the type seen on Mercury. Basin disruption effects appear to be limited. The most prominent occur around Evander (Dione) and southeast of Odysseus (Tethys) , where radial "gouge” erased the preexisting cratering record in favor of much smaller densely packed craters in an annulus around the basin which terminates at a circumferential ridge up to 2 km high! This may be a ring structure or distal ejecta ridge. Radial grooves may also occur near ancient relaxed basins on Dione and Rhea. Grooves 2-3 km deep on Mimas extend nearly globally but their relationship to Herschel is uncertain. Enceladus topography is dominated by pervasive resurfacing and by large-scale depressions (or dimples) that are plausibly due to isostatic variations in shell thickness.

  13. Dynamic topographic mapping of the human bladder during voiding using functional near-infrared spectroscopy.

    PubMed

    Macnab, Andrew; Stothers, Lynn; Shadgan, Babak

    2009-01-01

    Functional near-infrared spectroscopy (fNIRS) with multichannel instruments and grids of source-detector pairs can map regional change in oxygenation/hemodynamics. Developed for cortical brain mapping, fNIRS technology has relevance in other organs where pathology affects the microcirculation. We describe fNIRS of the human bladder for evaluation of hemodynamic change during voiding. A 5x5-cm grid with two source-detector pairs is placed on the abdomen suprapubically in an asymptomatic male. In four separate trials, after natural bladder filling NIRS-derived changes in oxyhemoglobin (O(2)Hb), deoxyhemoglobin (HHb), and total hemoglobin (tHb) concentration are recorded during voiding (measured via uroflow), using four channels of a four wavelength continuous wave instrument. Graphic and video images (topographic mapping software) are generated. Changes in tHb occur following permission to void that predominantly reflected variation in O(2)Hb; tHb peaks at maximum urine flow then falls to a nadir lasting to uroflow end. Change in fNIRS video color intensity correlates with graphic change in chromophore concentration. Color variations across the mapped area suggest regional hemodynamic variation. fNIRS bladder studies generate reproducible chromophore data consistent with single channel studies, but the dynamic color video and larger tissue area monitored potentially offer new methodology for investigating regional variations in bladder oxygenation and hemodynamics. PMID:19405712

  14. Dynamic topographic mapping of the human bladder during voiding using functional near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Macnab, Andrew; Stothers, Lynn; Shadgan, Babak

    2009-03-01

    Functional near-infrared spectroscopy (fNIRS) with multichannel instruments and grids of source-detector pairs can map regional change in oxygenation/hemodynamics. Developed for cortical brain mapping, fNIRS technology has relevance in other organs where pathology affects the microcirculation. We describe fNIRS of the human bladder for evaluation of hemodynamic change during voiding. A 5×5-cm grid with two source-detector pairs is placed on the abdomen suprapubically in an asymptomatic male. In four separate trials, after natural bladder filling NIRS-derived changes in oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), and total hemoglobin (tHb) concentration are recorded during voiding (measured via uroflow), using four channels of a four wavelength continuous wave instrument. Graphic and video images (topographic mapping software) are generated. Changes in tHb occur following permission to void that predominantly reflected variation in O2Hb; tHb peaks at maximum urine flow then falls to a nadir lasting to uroflow end. Change in fNIRS video color intensity correlates with graphic change in chromophore concentration. Color variations across the mapped area suggest regional hemodynamic variation. fNIRS bladder studies generate reproducible chromophore data consistent with single channel studies, but the dynamic color video and larger tissue area monitored potentially offer new methodology for investigating regional variations in bladder oxygenation and hemodynamics.

  15. AlphaSpace: Fragment-Centric Topographical Mapping To Target Protein–Protein Interaction Interfaces

    PubMed Central

    2016-01-01

    Inhibition of protein–protein interactions (PPIs) is emerging as a promising therapeutic strategy despite the difficulty in targeting such interfaces with drug-like small molecules. PPIs generally feature large and flat binding surfaces as compared to typical drug targets. These features pose a challenge for structural characterization of the surface using geometry-based pocket-detection methods. An attractive mapping strategy—that builds on the principles of fragment-based drug discovery (FBDD)—is to detect the fragment-centric modularity at the protein surface and then characterize the large PPI interface as a set of localized, fragment-targetable interaction regions. Here, we introduce AlphaSpace, a computational analysis tool designed for fragment-centric topographical mapping (FCTM) of PPI interfaces. Our approach uses the alpha sphere construct, a geometric feature of a protein’s Voronoi diagram, to map out concave interaction space at the protein surface. We introduce two new features—alpha-atom and alpha-space—and the concept of the alpha-atom/alpha-space pair to rank pockets for fragment-targetability and to facilitate the evaluation of pocket/fragment complementarity. The resulting high-resolution interfacial map of targetable pocket space can be used to guide the rational design and optimization of small molecule or biomimetic PPI inhibitors. PMID:26225450

  16. AlphaSpace: Fragment-Centric Topographical Mapping To Target Protein-Protein Interaction Interfaces.

    PubMed

    Rooklin, David; Wang, Cheng; Katigbak, Joseph; Arora, Paramjit S; Zhang, Yingkai

    2015-08-24

    Inhibition of protein-protein interactions (PPIs) is emerging as a promising therapeutic strategy despite the difficulty in targeting such interfaces with drug-like small molecules. PPIs generally feature large and flat binding surfaces as compared to typical drug targets. These features pose a challenge for structural characterization of the surface using geometry-based pocket-detection methods. An attractive mapping strategy--that builds on the principles of fragment-based drug discovery (FBDD)--is to detect the fragment-centric modularity at the protein surface and then characterize the large PPI interface as a set of localized, fragment-targetable interaction regions. Here, we introduce AlphaSpace, a computational analysis tool designed for fragment-centric topographical mapping (FCTM) of PPI interfaces. Our approach uses the alpha sphere construct, a geometric feature of a protein's Voronoi diagram, to map out concave interaction space at the protein surface. We introduce two new features--alpha-atom and alpha-space--and the concept of the alpha-atom/alpha-space pair to rank pockets for fragment-targetability and to facilitate the evaluation of pocket/fragment complementarity. The resulting high-resolution interfacial map of targetable pocket space can be used to guide the rational design and optimization of small molecule or biomimetic PPI inhibitors. PMID:26225450

  17. A web-based archive for topographic maps of retinal cell distribution in vertebrates.

    PubMed

    Collin, Shaun P

    2008-01-01

    Clinical and Experimental Optometry, in conjunction with Optometrists Association Australia and Professor Shaun P Collin of the University of Queensland, announce the launch of a web-based archive of previously published topographic maps of retinal cell distribution in vertebrates. At present, the archive boasts more than 770 different maps of the distribution of retinal neurons (for example, photoreceptors, bipolar cells, amacrine cells, horizontal cells and ganglion cells) in nearly 200 species within all vertebrate classes (Cephalospidomorpha, Actinopterygii, Sarcopterygii, Amphibia, Reptilia, Aves and Mammalia). The distribution of retinal neurons has been studied for more than 100 years and has become a powerful means of predicting the spatial resolving power of the eye and the retinal regions containing specialisations, such as areae centrales, horizontal streaks and foveae, where increased densities of neurons define the way in which a species visually samples its environment. The location of these retinal specialisations thereby identifies the part(s) of the visual field of critical importance for localising food and mates and for predator surveillance. The distribution of sampling elements even reflects the symmetry of a species' ecological habitat. The archive is a unique collection of most of the currently available retinal maps, which also presents relevant information, where known, about eye size, retinal cell density, retinal orientation, cell number, spatial resolving power and the type of specialisation, in addition to basic physical parameters of each species (body size, weight, sex and developmental stage). The archive is accessible at http://www.optometrists.asn.au/ceo/retinalsearch and will be updated regularly. The powerful database is interactive and freely available, providing the opportunity to upload both published and unpublished topographic maps. Following a review process, previously unpublished maps will be 'published' and available

  18. Accurate Mobile Urban Mapping via Digital Map-Based SLAM †.

    PubMed

    Roh, Hyunchul; Jeong, Jinyong; Cho, Younggun; Kim, Ayoung

    2016-01-01

    This paper presents accurate urban map generation using digital map-based Simultaneous Localization and Mapping (SLAM). Throughout this work, our main objective is generating a 3D and lane map aiming for sub-meter accuracy. In conventional mapping approaches, achieving extremely high accuracy was performed by either (i) exploiting costly airborne sensors or (ii) surveying with a static mapping system in a stationary platform. Mobile scanning systems recently have gathered popularity but are mostly limited by the availability of the Global Positioning System (GPS). We focus on the fact that the availability of GPS and urban structures are both sporadic but complementary. By modeling both GPS and digital map data as measurements and integrating them with other sensor measurements, we leverage SLAM for an accurate mobile mapping system. Our proposed algorithm generates an efficient graph SLAM and achieves a framework running in real-time and targeting sub-meter accuracy with a mobile platform. Integrated with the SLAM framework, we implement a motion-adaptive model for the Inverse Perspective Mapping (IPM). Using motion estimation derived from SLAM, the experimental results show that the proposed approaches provide stable bird's-eye view images, even with significant motion during the drive. Our real-time map generation framework is validated via a long-distance urban test and evaluated at randomly sampled points using Real-Time Kinematic (RTK)-GPS. PMID:27548175

  19. Mapping Soil Depth with Topographic and Land Cover Attributes from Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Chen, Cheng-Ru; Chen, Chi-Farn; Son, Nguyen-Thanh; Lau, Va-Khin

    2016-04-01

    Soil depth is an important parameter for identification of the overused slope land in Taiwan. The retrieval of high resolution soil depth at a large scale is costly and time-consuming. The main objective of this study is to develop an approach to estimate soil depths using satellite data with the aid of field survey data in Taiwan. The data were processed using the soil-landscape regression kriging model. The predictor variables, including elevation, slope, aspect, curvature, topographic wetness, spectral indices, and land use, derived from remotely sensed data were used as model inputs for the soil depth estimation. In this study, topographic attributes were derived from an 5-m resolution digital elevation model, and the land-use map and spectral indices were obtained through interpretation of Landsat-8 data. The absolute mean and root mean-square errors were used to access the reliability of the prediction, indicating a goodness-of-fit of the estimation model. The results of soil depth estimation compared with the field survey data indicated close relationship between these two datasets. The results obtained from this study could spatially provide quantitative information of soil depths, which is an important indicator for assessing the overused slope land. The methods were thus proposed for retrieval of soil depths in Taiwan.

  20. Physiological organization and topographic mapping of the antennal olfactory sensory neurons in female hawkmoths, Manduca sexta.

    PubMed

    Ghaninia, Majid; Olsson, Shannon B; Hansson, Bill S

    2014-10-01

    The hawkmoth, Manduca sexta, has been a keystone system for developmental, neurobiological, and ecological studies for several decades. Because many of its behaviors are driven by olfactory cues, a thorough understanding of the Manduca olfactory system is essential to studying its biology. With the aim of functionally characterizing single antennal olfactory sensory neurons (OSNs) and determining their detailed topographic location, we performed systematic single-sensillum recordings on 4 morphological types of olfactory sensilla: trichoid-A and -B and basiconic-A and -B. We were able to unambiguously differentiate the colocalized cells associated with single sensilla based on their spike amplitudes. Using a panel of 61 biologically relevant compounds established in behavioral and gas chromatography-electrophysiology experiments, we made 223 recordings from these sensilla. Based on the response spectra of 187 responding OSNs, the sensilla fell into 12 distinct functional classes encompassing 29 OSNs. Selectivity of the 25 responding OSNs varied from narrowly tuned (responding to only one or a subset of compounds), to very broadly tuned (responding to multiple compounds), in a concentration-dependent manner. Four OSNs, however, did not respond to the tested components. Topographic mapping of the sensilla revealed that some physiological sensillum types are confined to particular locations on the antennal surface while other classes are more or less irregularly scattered all over the antennal annuli. Such information will prove beneficial for future receptor deorphanization, in situ hybridization, and molecular manipulation experiments. PMID:25092901

  1. An Integrative Method for Accurate Comparative Genome Mapping

    PubMed Central

    Swidan, Firas; Rocha, Eduardo P. C; Shmoish, Michael; Pinter, Ron Y

    2006-01-01

    We present MAGIC, an integrative and accurate method for comparative genome mapping. Our method consists of two phases: preprocessing for identifying “maximal similar segments,” and mapping for clustering and classifying these segments. MAGIC's main novelty lies in its biologically intuitive clustering approach, which aims towards both calculating reorder-free segments and identifying orthologous segments. In the process, MAGIC efficiently handles ambiguities resulting from duplications that occurred before the speciation of the considered organisms from their most recent common ancestor. We demonstrate both MAGIC's robustness and scalability: the former is asserted with respect to its initial input and with respect to its parameters' values. The latter is asserted by applying MAGIC to distantly related organisms and to large genomes. We compare MAGIC to other comparative mapping methods and provide detailed analysis of the differences between them. Our improvements allow a comprehensive study of the diversity of genetic repertoires resulting from large-scale mutations, such as indels and duplications, including explicitly transposable and phagic elements. The strength of our method is demonstrated by detailed statistics computed for each type of these large-scale mutations. MAGIC enabled us to conduct a comprehensive analysis of the different forces shaping prokaryotic genomes from different clades, and to quantify the importance of novel gene content introduced by horizontal gene transfer relative to gene duplication in bacterial genome evolution. We use these results to investigate the breakpoint distribution in several prokaryotic genomes. PMID:16933978

  2. The Topographic Data Deluge - Collecting and Maintaining Data in a 21ST Century Mapping Agency

    NASA Astrophysics Data System (ADS)

    Holland, D. A.; Pook, C.; Capstick, D.; Hemmings, A.

    2016-06-01

    In the last few years, the number of sensors and data collection systems available to a mapping agency has grown considerably. In the field, in addition to total stations measuring position, angles and distances, the surveyor can choose from hand-held GPS devices, multi-lens imaging systems or laser scanners, which may be integrated with a laptop or tablet to capture topographic data directly in the field. These systems are joined by mobile mapping solutions, mounted on large or small vehicles, or sometimes even on a backpack carried by a surveyor walking around a site. Such systems allow the raw data to be collected rapidly in the field, while the interpretation of the data can be performed back in the office at a later date. In the air, large format digital cameras and airborne lidar sensors are being augmented with oblique camera systems, taking multiple views at each camera position and being used to create more realistic 3D city models. Lower down in the atmosphere, Unmanned Aerial Vehicles (or Remotely Piloted Aircraft Systems) have suddenly become ubiquitous. Hundreds of small companies have sprung up, providing images from UAVs using ever more capable consumer cameras. It is now easy to buy a 42 megapixel camera off the shelf at the local camera shop, and Canon recently announced that they are developing a 250 megapixel sensor for the consumer market. While these sensors may not yet rival the metric cameras used by today's photogrammetrists, the rapid developments in sensor technology could eventually lead to the commoditization of high-resolution camera systems. With data streaming in from so many sources, the main issue for a mapping agency is how to interpret, store and update the data in such a way as to enable the creation and maintenance of the end product. This might be a topographic map, ortho-image or a digital surface model today, but soon it is just as likely to be a 3D point cloud, textured 3D mesh, 3D city model, or Building Information Model

  3. MapSplice: Accurate mapping of RNA-seq reads for splice junction discovery

    PubMed Central

    Wang, Kai; Singh, Darshan; Zeng, Zheng; Coleman, Stephen J.; Huang, Yan; Savich, Gleb L.; He, Xiaping; Mieczkowski, Piotr; Grimm, Sara A.; Perou, Charles M.; MacLeod, James N.; Chiang, Derek Y.; Prins, Jan F.; Liu, Jinze

    2010-01-01

    The accurate mapping of reads that span splice junctions is a critical component of all analytic techniques that work with RNA-seq data. We introduce a second generation splice detection algorithm, MapSplice, whose focus is high sensitivity and specificity in the detection of splices as well as CPU and memory efficiency. MapSplice can be applied to both short (<75 bp) and long reads (≥75 bp). MapSplice is not dependent on splice site features or intron length, consequently it can detect novel canonical as well as non-canonical splices. MapSplice leverages the quality and diversity of read alignments of a given splice to increase accuracy. We demonstrate that MapSplice achieves higher sensitivity and specificity than TopHat and SpliceMap on a set of simulated RNA-seq data. Experimental studies also support the accuracy of the algorithm. Splice junctions derived from eight breast cancer RNA-seq datasets recapitulated the extensiveness of alternative splicing on a global level as well as the differences between molecular subtypes of breast cancer. These combined results indicate that MapSplice is a highly accurate algorithm for the alignment of RNA-seq reads to splice junctions. Software download URL: http://www.netlab.uky.edu/p/bioinfo/MapSplice. PMID:20802226

  4. MapSplice: accurate mapping of RNA-seq reads for splice junction discovery.

    PubMed

    Wang, Kai; Singh, Darshan; Zeng, Zheng; Coleman, Stephen J; Huang, Yan; Savich, Gleb L; He, Xiaping; Mieczkowski, Piotr; Grimm, Sara A; Perou, Charles M; MacLeod, James N; Chiang, Derek Y; Prins, Jan F; Liu, Jinze

    2010-10-01

    The accurate mapping of reads that span splice junctions is a critical component of all analytic techniques that work with RNA-seq data. We introduce a second generation splice detection algorithm, MapSplice, whose focus is high sensitivity and specificity in the detection of splices as well as CPU and memory efficiency. MapSplice can be applied to both short (<75 bp) and long reads (≥ 75 bp). MapSplice is not dependent on splice site features or intron length, consequently it can detect novel canonical as well as non-canonical splices. MapSplice leverages the quality and diversity of read alignments of a given splice to increase accuracy. We demonstrate that MapSplice achieves higher sensitivity and specificity than TopHat and SpliceMap on a set of simulated RNA-seq data. Experimental studies also support the accuracy of the algorithm. Splice junctions derived from eight breast cancer RNA-seq datasets recapitulated the extensiveness of alternative splicing on a global level as well as the differences between molecular subtypes of breast cancer. These combined results indicate that MapSplice is a highly accurate algorithm for the alignment of RNA-seq reads to splice junctions. Software download URL: http://www.netlab.uky.edu/p/bioinfo/MapSplice. PMID:20802226

  5. Initial Results of 3D Topographic Mapping Using Lunar Reconnaissance Orbiter Camera (LROC) Stereo Imagery

    NASA Astrophysics Data System (ADS)

    Li, R.; Oberst, J.; McEwen, A. S.; Archinal, B. A.; Beyer, R. A.; Thomas, P. C.; Chen, Y.; Hwangbo, J.; Lawver, J. D.; Scholten, F.; Mattson, S. S.; Howington-Kraus, A. E.; Robinson, M. S.

    2009-12-01

    The Lunar Reconnaissance Orbiter (LRO), launched June 18, 2009, carries the Lunar Reconnaissance Orbiter Camera (LROC) as one of seven remote sensing instruments on board. The camera system is equipped with a Wide Angle Camera (WAC) and two Narrow Angle Cameras (NAC) for systematic lunar surface mapping and detailed site characterization for potential landing site selection and resource identification. The LROC WAC is a pushframe camera with five 14-line by 704-sample framelets for visible light bands and two 16-line by 512-sample (summed 4x to 4 by 128) UV bands. The WAC can also acquire monochrome images with a 14-line by 1024-sample format. At the nominal 50-km orbit the visible bands ground scale is 75-m/pixel and the UV 383-m/pixel. Overlapping WAC images from adjacent orbits can be used to map topography at a scale of a few hundred meters. The two panchromatic NAC cameras are pushbroom imaging sensors each with a Cassegrain telescope of a 700-mm focal length. The two NAC cameras are aligned with a small overlap in the cross-track direction so that they cover a 5-km swath with a combined field-of-view (FOV) of 5.6°. At an altitude of 50-km, the NAC can provide panchromatic images from its 5,000-pixel linear CCD at a ground scale of 0.5-m/pixel. Calibration of the cameras was performed by using precision collimator measurements to determine the camera principal points and radial lens distortion. The orientation of the two NAC cameras is estimated by a boresight calibration using double and triple overlapping NAC images of the lunar surface. The resulting calibration results are incorporated into a photogrammetric bundle adjustment (BA), which models the LROC camera imaging geometry, in order to refine the exterior orientation (EO) parameters initially retrieved from the SPICE kernels. Consequently, the improved EO parameters can significantly enhance the quality of topographic products derived from LROC NAC imagery. In addition, an analysis of the spacecraft

  6. Characterizing arid region alluvial fan surface roughness with airborne laser swath mapping digital topographic data

    NASA Astrophysics Data System (ADS)

    Frankel, Kurt L.; Dolan, James F.

    2007-06-01

    Range-front alluvial fan deposition in arid environments is episodic and results in multiple fan surfaces and ages. These distinct landforms are often defined by descriptions of their surface morphology, desert varnish accumulation, clast rubification, desert pavement formation, soil development, and stratigraphy. Although quantifying surface roughness differences between alluvial fan units has proven to be difficult in the past, high-resolution airborne laser swath mapping (ALSM) digital topographic data are now providing researchers with an opportunity to study topography in unprecedented detail. Here we use ALSM data to calculate surface roughness on two alluvial fans in northern Death Valley, California. We define surface roughness as the standard deviation of slope in a 5-m by 5-m moving window. Comparison of surface roughness values between mapped fan surfaces shows that each unit is statistically unique at the 99% confidence level. Furthermore, there is an obvious smoothing trend from the presently active channel to a deposit with cosmogenic 10Be and 36Cl surface exposure ages of ˜70 ka. Beyond 70 ka, alluvial landforms become progressively rougher with age. These data suggest that alluvial fans in arid regions smooth out with time until a threshold is crossed where roughness increases at greater wavelength with age as a result of surface runoff and headward tributary incision into the oldest surfaces.

  7. Aerial radiometric and magnetic survey: Hobbs National Topographic Map, New Mexico/Texas. Final report

    SciTech Connect

    Not Available

    1980-05-01

    The results of analyses of the airborne gamma radiation and total magnetic field survey flown for the region identified as the Hobbs National Topographic Map NI13-12 are presented in this report. The airborne data gathered are reduced by ground computer facilities to yield profile plots of the basic uranium, thorium and potassium equivalent gamma radiation intensities, ratios of these intensities, aircraft altitude above the earth's surface, total gamma ray and earth's magnetic field intensity, correlated as a function of geologic units. The distribution of data within each geologic unit, for all surveyed map lines and tie lines, has been calculated and is included. Two sets of profiled data for each line are included, with one set displaying the above-cited data. The second set includes only flight line magnetic field, temperature, pressure, altitude data plus magnetic field data as measured at a base station. A general description of the area, including descriptions of the various geologic units and the corresponding airborne data, is included also.

  8. Aerial radiometric and magnetic survey, San Angelo National Topographic Map: Texas, West Texas Project. Final report

    SciTech Connect

    Not Available

    1980-05-01

    The results of analyses of the airborne gamma radiation and total magnetic field survey flown for the region identified as the San Angelo National Topographic Map NH14-1 are presented. The airborne data gathered are reduced by ground computer facilities to yield profile plots of the basic uranium, thorium, and potassium equivalent gamma radiation intensities, ratios of these intensities, aircraft altitude above the earth's surface, total gamma ray and earth's magnetic field intensity, correlated as a function of geologic units. The distribution of data within each geologic unit, for all surveyed map lines and tie lines, has been calculated and is included. Two sets of profiled data for each line are included, with one set displaying the above-cited data. The second set includes only flight line magnetic field, temperature, pressure, altitude data plus magnetic field data as measured at a base station. A general description of the area, including descriptions of the various geologic units and the corresponding airborne data, is included.

  9. Aerial radiometric and magnetic survey: San Antonio National Topographic Map, Texas. Final report

    SciTech Connect

    Not Available

    1980-05-01

    The results of analyses of the airborne gamma radiation and total magnetic field survey flown for the region identified as the San Antonio National Topographic Map NH14-8 are presented. The airborne data gathered are reduced by ground computer facilities to yield profile plots of the basic uranium, thorium, and potassium equivalent gamma radiation intensities, ratios of these intensities, aircraft altitude above the earth's surface, total gamma ray and earth's magnetic field intensity, correlated as a function of geologic units. The distribution of data within each geologic unit, for all surveyed map lines and tie lines, has been calculated and is included. Two sets of profiled data for each line are included, with one set displaying the above-cited data. The second set includes only flight line magnetic field, temperature, pressure, altitude data plus magnetic field data as measured at a base station. A general description of the area, including descriptions of the various geologic units and the corresponding airborne data, is included also.

  10. Aerial radiometric and magnetic survey: Burlington National Topographic Map, Illinois/Iowa/Missouri

    SciTech Connect

    Not Available

    1981-01-01

    The results of analyses of the airborne gamma radiation and total magnetic field survey flown for the region identified as the Burlington National Topographic Map NK15-12 is presented in this report. The airborne data gathered is reduced by ground computer facilities to yield profile plots of the basic uranium, thorium and potassium equivalent gamma radiation intensities, ratios of these intensities, aircraft altitude above the earth's surface, total gamma ray and earth's magnetic field intensity, correlated as a function of geologic units. The distribution of data within each geologic unit, for all surveyed map lines and tie lines, has been calculated and is included. Two sets of profiled data for each line are included, with one set displaying the above-cited data. The second set includes only flight line magnetic field, temperature, pressure, altitude data plus magnetic field data as measured at a base station. A general description of the area, including descriptions of the various geologic units and the corresponding airborne data, is included also.

  11. Volumetric evolution of Surtsey, Iceland, from topographic maps and scanning airborne laser altimetry

    USGS Publications Warehouse

    Garvin, J.B.; Williams, R.S.; Frawley, J.J.; Krabill, W.B.

    2000-01-01

    The volumetric evolution of Surtsey has been estimated on the basis of digital elevation models derived from NASA scanning airborne laser altimeter surveys (20 July 1998), as well as digitized 1:5,000-scale topographic maps produced by the National Land Survey of Iceland and by Norrman. Subaerial volumes have been computed from co-registered digital elevation models (DEM's) from 6 July 1968, 11 July 1975, 16 July 1993, and 20 July 1998 (scanning airborne laser altimetry), as well as true surface area (above mean sea level). Our analysis suggests that the subaerial volume of Surtsey has been reduced from nearly 0.100 km3 on 6 July 1968 to 0.075 km3 on 20 July 1998. Linear regression analysis of the temporal evolution of Surtsey's subaerial volume indicates that most of its subaerial surface will be at or below mean sea-level by approximately 2100. This assumes a conservative estimate of continuation of the current pace of marine erosion and mass-wasting on the island, including the indurated core of the conduits of the Surtur I and Surtur II eruptive vents. If the conduits are relatively resistant to marine erosion they will become sea stacks after the rest of the island has become a submarine shoal, and some portions of the island could survive for centuries. The 20 July 1998 scanning laser altimeter surveys further indicate rapid enlargement of erosional canyons in the northeastern portion of the partial tephra ring associated with Surtur I. Continued airborne and eventually spaceborne topographic surveys of Surtsey are planned to refine the inter-annual change of its subaerial volume.

  12. Covariance of biophysical data with digital topographic and land use maps over the FIFE site

    NASA Astrophysics Data System (ADS)

    Davis, F. W.; Schimel, D. S.; Friedl, M. A.; Michaelsen, J. C.; Kittel, T. G. F.; Dubayah, R.; Dozier, J.

    1992-11-01

    Sampling design is critical in locating ground sampling stations for large-scale climatological field experiments. In the stratified sampling design adopted for the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE), the study region was stratified into 14 different terrain units based on land use/land cover and topographic variables that were hypothesized to have a strong influence on surface biophysical properties. Digital terrain maps were produced to facilitate ground data integration and extrapolation. This paper describes the biophysical stratification of the FIFE site, implementation of the stratification using geographic information system (GIS) techniques, and validation of the stratification with respect to field measurements of biomass, soil moisture, Bowen ratio (β), and the greenness vegetation index (GVI) derived from thematic mapper satellite data. Maps of burning and topographic position were significantly associated with variation in biomass, GVI, and β. The effects of burning and topography were stronger for the Konza Prairie Long-Term Ecological Research (KPLTER) site than for the rest of the FIFE site, where cattle grazing was a major confounding effect. The stratified design did not appreciably change the estimated site-wide means for surface climate parameters but accounted for between 25 and 45% of the sample variance depending on the variable. The design was weakened by undersampling of several strata, by high within-station variance in soil and vegetation data, and by failure to account for diverse land management practices on private lands surrounding KPLTER. We recommend that future large-scale climatological studies include the development of a digital terrain data base well in advance of field campaigns and that multitemporal imagery be used to obtain preliminary estimates of spatial and temporal variance in surface biophysical properties. We also recommend that sampling for the most

  13. A Neural Field Model of the Somatosensory Cortex: Formation, Maintenance and Reorganization of Ordered Topographic Maps

    PubMed Central

    Detorakis, Georgios Is.; Rougier, Nicolas P.

    2012-01-01

    We investigate the formation and maintenance of ordered topographic maps in the primary somatosensory cortex as well as the reorganization of representations after sensory deprivation or cortical lesion. We consider both the critical period (postnatal) where representations are shaped and the post-critical period where representations are maintained and possibly reorganized. We hypothesize that feed-forward thalamocortical connections are an adequate site of plasticity while cortico-cortical connections are believed to drive a competitive mechanism that is critical for learning. We model a small skin patch located on the distal phalangeal surface of a digit as a set of 256 Merkel ending complexes (MEC) that feed a computational model of the primary somatosensory cortex (area 3b). This model is a two-dimensional neural field where spatially localized solutions (a.k.a. bumps) drive cortical plasticity through a Hebbian-like learning rule. Simulations explain the initial formation of ordered representations following repetitive and random stimulations of the skin patch. Skin lesions as well as cortical lesions are also studied and results confirm the possibility to reorganize representations using the same learning rule and depending on the type of the lesion. For severe lesions, the model suggests that cortico-cortical connections may play an important role in complete recovery. PMID:22808127

  14. Delineating recharge areas for stratified-drift aquifers in Connecticut with geologic and topographic maps

    USGS Publications Warehouse

    Handman, E.H.

    1986-01-01

    Stratified-drift aquifers, the major source of large quantities of groundwater in Connecticut, are recharged principally by (1) precipitation that infiltrates the land surface overlying the aquifer and percolates downward to the saturated zone, (2) subsurface inflow of groundwater from adjacent till-and-bedrock uplands, and (3) surface water that infiltrates through streambed or lake-bottom sediments. Infiltration of surface water commonly occurs where pumping wells lower then water table sufficiently to reverse the normal hydraulic gradient between the aquifer and nearly surface-water body to which it is hydraulically connected. In most parts of Connecticut, groundwater circulation in unconsolidated deposits is probably confined within each basin drained by a major perrennial stream. Where this is the case, surface water and groundwater drainage divides commonly coincide, and areas that contribute recharge under natural conditions and under conditions of development can be estimated using geologic and topographic maps. Large stratified-drift aquifers that extend across surface water drainage, divides underlie most of north-central Connecticut and parts of the Quinnipiac and Farmington River basins. Definition of recharge areas for these aquifers is more complicated and requires more detailed hydrologic information. (USGS)

  15. ATLAS: an airborne active linescan system for high-resolution topographic mapping

    NASA Astrophysics Data System (ADS)

    Willetts, David V.; Kightley, Peter J.; Mole, S. G.; Pearson, Guy N.; Pearson, P.; Coffey, Adrian S.; Stokes, Tim J.; Tapster, Paul R.; Westwood, M.

    2004-12-01

    High resolution ground mapping is of interest for survey and management of long linear features such as roads, railways and pipelines, and for georeferencing of areas such as flood plains for hydrological purposes. ATLAS (Airborne Topographic Laser System) is an active linescan system operating at the eyesafe wavelength of 1.5μm. Built for airborne survey, it is currently certified for use on a Twin Squirrel helicopter for operation from low levels to heights above 500 feet allowing commercial survey in built up areas. The system operates at a pulse repetition frequency of 56kHz with a line completed in 15ms, giving 36 points/m2 at the surface at the design flight speed. At each point the range to the ground is measured together with the scan angle of the system. This data is combined with a system attitude measurement from an integrated inertial navigation system and with system position derived from differential GPS data aboard the platform. A recording system captures the data with a synchronised time-stamp to enable post-processed reconstruction of a cloud of data points that will give a three-dimensional representation of the terrain, allowing the points to be located with respect to absolute Earth referenced coordinates to a precision of 5cm in three axes. This paper summarises the design, harmonisation, evaluation and performance of the system, and shows examples of survey data.

  16. Spirit rover localization and topographic mapping at the landing site of Gusev crater, Mars

    USGS Publications Warehouse

    Li, R.; Archinal, B.A.; Arvidson, R. E.; Bell, J.; Christensen, P.; Crumpler, L.; Des Marais, D.J.; Di, K.; Duxbury, T.; Golombek, M.P.; Grant, J. A.; Greeley, R.; Guinn, J.; Johnson, Aaron H.; Kirk, R.L.; Maimone, M.; Matthies, L.H.; Malin, M.; Parker, T.; Sims, M.; Thompson, S.; Squyres, S. W.; Soderblom, L.A.

    2006-01-01

    By sol 440, the Spirit rover has traversed a distance of 3.76 km (actual distance traveled instead of odometry). Localization of the lander and the rover along the traverse has been successfully performed at the Gusev crater landing site. We localized the lander in the Gusev crater using two-way Doppler radio positioning and cartographic triangulations through landmarks visible in both orbital and ground images. Additional high-resolution orbital images were used to verify the determined lander position. Visual odometry and bundle adjustment technologies were applied to compensate for wheel slippage, azimuthal angle drift, and other navigation errors (which were as large as 10.5% in the Husband Hill area). We generated topographic products, including 72 ortho maps and three-dimensional (3-D) digital terrain models, 11 horizontal and vertical traverse profiles, and one 3-D crater model (up to sol 440). Also discussed in this paper are uses of the data for science operations planning, geological traverse surveys, surveys of wind-related features, and other science applications. Copyright 2006 by the American Geophysical Union.

  17. Topographic Mapmaking.

    ERIC Educational Resources Information Center

    Meunier, Tony K.

    1980-01-01

    The making of topographic maps is described as a sequence of the following steps: establishment of control, photogrammetry and field operations, annotation of photographs, stereoplatting, editing, preparation of color-separation plates, and printing. Precise standards are emphasized. (Author/SA)

  18. Merged Shape from Shading and Shape from Stereo for Planetary Topographic Mapping

    NASA Astrophysics Data System (ADS)

    Tyler, Laurence; Cook, Tony; Barnes, Dave; Parr, Gerhard; Kirk, Randolph

    2014-05-01

    Digital Elevation Models (DEMs) of the Moon and Mars have traditionally been produced from stereo imagery from orbit, or from the surface landers or rovers. One core component of image-based DEM generation is stereo matching to find correspondences between images taken from different viewpoints. Stereo matchers that rely mostly on textural features in the images can fail to find enough matched points in areas lacking in contrast or surface texture. This can lead to blank or topographically noisy areas in resulting DEMs. Fine depth detail may also be lacking due to limited precision and quantisation of the pixel matching process. Shape from shading (SFS), a two dimensional version of photoclinometry, utilizes the properties of light reflecting off surfaces to build up localised slope maps, which can subsequently be combined to extract topography. This works especially well on homogeneous surfaces and can recover fine detail. However the cartographic accuracy can be affected by changes in brightness due to differences in surface material, albedo and light scattering properties, and also by the presence of shadows. We describe here experimental research for the Planetary Robotics Vision Data Exploitation EU FP7 project (PRoViDE) into using stereo generated depth maps in conjunction with SFS to recover both coarse and fine detail of planetary surface DEMs. Our Large Deformation Optimisation Shape From Shading (LDOSFS) algorithm uses image data, illumination, viewing geometry and camera parameters to produce a DEM. A stereo-derived depth map can be used as an initial seed if available. The software uses separate Bidirectional Reflectance Distribution Function (BRDF) and SFS modules for iterative processing and to make the code more portable for future development. Three BRDF models are currently implemented: Lambertian, Blinn-Phong, and Oren-Nayar. A version of the Hapke reflectance function, which is more appropriate for planetary surfaces, is under development

  19. On the accurate construction of consensus genetic maps.

    PubMed

    Wu, Yonghui; Close, Timothy J; Lonardi, Stefano

    2008-01-01

    We study the problem of merging genetic maps, when the individual genetic maps are given as directed acyclic graphs. The problem is to build a consensus map, which includes and is consistent with all (or, the vast majority of) the markers in the individual maps. When markers in the input maps have ordering conflicts, the resulting consensus map will contain cycles. We formulate the problem of resolving cycles in a combinatorial optimization framework, which in turn is expressed as an integer linear program. A faster approximation algorithm is proposed, and an additional speed-up heuristic is developed. According to an extensive set of experimental results, our tool is consistently better than JOINMAP, both in terms of accuracy and running time. PMID:19642288

  20. Accurate construction of consensus genetic maps via integer linear programming.

    PubMed

    Wu, Yonghui; Close, Timothy J; Lonardi, Stefano

    2011-01-01

    We study the problem of merging genetic maps, when the individual genetic maps are given as directed acyclic graphs. The computational problem is to build a consensus map, which is a directed graph that includes and is consistent with all (or, the vast majority of) the markers in the input maps. However, when markers in the individual maps have ordering conflicts, the resulting consensus map will contain cycles. Here, we formulate the problem of resolving cycles in the context of a parsimonious paradigm that takes into account two types of errors that may be present in the input maps, namely, local reshuffles and global displacements. The resulting combinatorial optimization problem is, in turn, expressed as an integer linear program. A fast approximation algorithm is proposed, and an additional speedup heuristic is developed. Our algorithms were implemented in a software tool named MERGEMAP which is freely available for academic use. An extensive set of experiments shows that MERGEMAP consistently outperforms JOINMAP, which is the most popular tool currently available for this task, both in terms of accuracy and running time. MERGEMAP is available for download at http://www.cs.ucr.edu/~yonghui/mgmap.html. PMID:20479505

  1. Application of GNSS-RTK derived topographical maps for rapid environmental monitoring: a case study of Jack Finnery Lake (Perth, Australia).

    PubMed

    Schloderer, Glen; Bingham, Matthew; Awange, Joseph L; Fleming, Kevin M

    2011-09-01

    In environmental monitoring, environmental impact assessments and environmental audits, topographical maps play an essential role in providing a means by which the locations of sampling sites may be selected, in assisting with the interpretation of physical features, and in indicating the impact or potential impact on an area due to changes in the system being monitored (e.g., spatially changing features such as wetlands). Global Navigation Satellite Systems (GNSS) are hereby presented as a rapid method for monitoring spatial changes to support environmental monitoring decisions and policies. To validate the GNSS-based method, a comparison is made of results from a small-scale topographic survey using radio-based real-time kinematic GNSS (GNSS-RTK) and total station survey methods at Jack Finnery Lake, Perth, Australia. The accuracies achieved by the total station in this study were 2 cm horizontally and 6 cm vertically, while the GNSS-RTK also achieved an accuracy of 2 cm horizontally, but only 28 cm vertically. While the GNSS-RTK measurements were less accurate in the height component compared to those from the total station method, it is still capable of achieving accuracies sufficient for a topographic map at a scale of 1:1,750 that could support environmental monitoring tasks such as identifying spatial changes in small water bodies or wetlands. The time taken to perform the survey using GNSS-RTK, however, was much shorter compared to the total station method, thereby making it quite suitable for monitoring spatial changes within an environmental context, e.g., dynamic mining activities that require rapid surveys and the updating of the monitored data at regular intervals. PMID:21136293

  2. Evaluation and parameterization of ATCOR3 topographic correction method for forest cover mapping in mountain areas

    NASA Astrophysics Data System (ADS)

    Balthazar, Vincent; Vanacker, Veerle; Lambin, Eric F.

    2012-08-01

    A topographic correction of optical remote sensing data is necessary to improve the quality of quantitative forest cover change analyses in mountainous terrain. The implementation of semi-empirical correction methods requires the calibration of model parameters that are empirically defined. This study develops a method to improve the performance of topographic corrections for forest cover change detection in mountainous terrain through an iterative tuning method of model parameters based on a systematic evaluation of the performance of the correction. The latter was based on: (i) the general matching of reflectances between sunlit and shaded slopes and (ii) the occurrence of abnormal reflectance values, qualified as statistical outliers, in very low illuminated areas. The method was tested on Landsat ETM+ data for rough (Ecuadorian Andes) and very rough mountainous terrain (Bhutan Himalayas). Compared to a reference level (no topographic correction), the ATCOR3 semi-empirical correction method resulted in a considerable reduction of dissimilarities between reflectance values of forested sites in different topographic orientations. Our results indicate that optimal parameter combinations are depending on the site, sun elevation and azimuth and spectral conditions. We demonstrate that the results of relatively simple topographic correction methods can be greatly improved through a feedback loop between parameter tuning and evaluation of the performance of the correction model.

  3. Facial whisker pattern is not sufficient to instruct a whisker-related topographic map in the mouse somatosensory brainstem.

    PubMed

    Laumonnerie, Christophe; Bechara, Ahmad; Vilain, Nathalie; Kurihara, Yukiko; Kurihara, Hiroki; Rijli, Filippo M

    2015-11-01

    Facial somatosensory input is relayed by trigeminal ganglion (TG) neurons and serially wired to brainstem, thalamus and cortex. Spatially ordered sets of target neurons generate central topographic maps reproducing the spatial arrangement of peripheral facial receptors. Facial pattern provides a necessary template for map formation, but may be insufficient to impose a brain somatotopic pattern. In mice, lower jaw sensory information is relayed by the trigeminal nerve mandibular branch, whose axons target the brainstem dorsal principal sensory trigeminal nucleus (dPrV). Input from mystacial whiskers is relayed by the maxillary branch and forms a topographic representation of rows and whiskers in the ventral PrV (vPrV). To investigate peripheral organisation in imposing a brain topographic pattern, we analysed Edn1(-/-) mice, which present ectopic whisker rows on the lower jaw. We found that these whiskers were innervated by mandibular TG neurons which initially targeted dPrV. Unlike maxillary TG neurons, the ectopic whisker-innervating mandibular neuron cell bodies and pre-target central axons did not segregate into a row-specific pattern nor target the dPrV with a topographic pattern. Following periphery-driven molecular repatterning to a maxillary-like identity, mandibular neurons partially redirected their central projections from dPrV to vPrV. Thus, while able to induce maxillary-like molecular features resulting in vPrV final targeting, a spatially ordered lower jaw ectopic whisker pattern is insufficient to impose row-specific pre-target organisation of the central mandibular tract or a whisker-related matching pattern of afferents in dPrV. These results provide novel insights into periphery-dependent versus periphery-independent mechanisms of trigeminal ganglion and brainstem patterning in matching whisker topography. PMID:26417040

  4. Probabilistic and single-subject retinotopic maps reveal the topographic organization of face patches in the macaque cortex.

    PubMed

    Janssens, Thomas; Zhu, Qi; Popivanov, Ivo D; Vanduffel, Wim

    2014-07-30

    Face perception is crucial to survival among social primates. It has been suggested that a group of extrastriate cortical regions responding more strongly to faces than to nonface objects is critical for face processing in primates. It is generally assumed that these regions are not retinotopically organized, as with human face-processing areas, showing foveal bias but lacking any organization with respect to polar angle. Despite many electrophysiological studies targeting monkey face patches, the retinotopic organization of these patches remains largely unclear. We have examined the relationship between cortical face patches and the topographic organization of extrastriate cortex using biologically relevant, phase-encoded retinotopic mapping stimuli in macaques. Single-subject fMRI results indicated a gradual shift from highly retinotopic to no topographic organization from posterior to anterior face patches in inferotemporal cortex. We also constructed a probabilistic retinotopic atlas of occipital and ventral extrastriate visual cortex. By comparing this probabilistic map to the locations of face patches at the group level, we showed that a previously identified posterior lateral temporal face patch (PL) is located within the posterior inferotemporal dorsal (PITd) retinotopic area. Furthermore, we identified a novel face patch posterior PL, which is located in retinotopically organized transitional area V4 (V4t). Previously published coordinates of human PITd coincide with the group-level occipital face area (OFA), according to a probabilistic map derived from a large population, implying a potential correspondence between monkey PL/PITd and human OFA/PITd. Furthermore, the monkey middle lateral temporal face patch (ML) shows consistent foveal biases but no obvious polar-angle structure. In contrast, middle fundus temporal (MF), anterior temporal and prefrontal monkey face patches lacked topographic organization. PMID:25080579

  5. Fiber tract-driven topographical mapping (FTTM) reveals microstructural relevance for interhemispheric visuomotor function in the aging brain

    PubMed Central

    Schulte, Tilman; Maddah, Mahnaz; Müller-Oehring, Eva M.; Rohlfing, Torsten; Pfefferbaum, Adolf; Sullivan, Edith V.

    2013-01-01

    We present a novel approach – DTI-based fiber tract-driven topographical mapping (FTTM) – to map and measure the influence of age on the integrity of interhemispheric fibers and challenge their selective functions with measures of interhemispheric integration of lateralized information. This approach enabled identification of spatially specific topographical maps of scalar diffusion measures and their relation to measures of visuomotor performance. Relative to younger adults, older adults showed lower fiber integrity indices in anterior than posterior callosal fibers. FTTM analysis identified a dissociation in the microstructural – function associates between age groups: in younger adults, genu fiber integrity correlated with interhemispheric transfer time, whereas in older adults, body fiber integrity was correlated with interhemispheric transfer time with topographical specificity along left-lateralized callosal fiber trajectories. Neural co-activation from redundant targets was evidenced by fMRI-derived bilateral extrastriate cortex activation in both groups, and a group difference emerged for a pontine activation cluster that was differently modulated by response hand in older than younger adults. Bilateral processing advantages in older but not younger adults further correlated with fiber integrity in transverse pontine fibers that branch into the right cerebellar cortex, thereby supporting a role for the pons in interhemispheric facilitation. In conclusion, in the face of compromised anterior callosal fibers, older adults appear to use alternative pathways to accomplish visuomotor interhemispheric information transfer and integration for lateralized processing. This shift from youthful associations may indicate recruitment of compensatory mechanisms involving medial corpus callosum fibers and subcortical pathways. PMID:23567886

  6. An Accurate NH Map of the North Ecliptic Pole

    NASA Astrophysics Data System (ADS)

    Elvis, M.; Lockman, F. J.; Fassnacht, C.

    1999-02-01

    The Galactic HI column density was measured at 21arcmin angular resolution over an 8 by 9 degree region centered on the North Ecliptic Pole, with the NRAO 140ft telescope and a technique to remove stray radiation (Lockman, Jahoda & McCammon 1986, ApJ, 302, 432). Over the region NH varies smoothly between 3e20 atoms/cm2 and 8e20 atoms/cm2. The map is given here. A spin temperature of 250K is assumed. Units are 10^18 atoms/cm2. The center is the NEP at 18 hours +66 degrees. The paper discusses the structure seen over most of the map on an 0.5 to 1 degree scale. There are other possible sources of interstellar opacity in this direction which may add an equivalent 1e20 atoms/cm2 of HI. We evaluate the effect of uncertainties in the HI column density on inferred X-ray fluxes of extragalactic objects.

  7. Topographic Map of Quadrangle 3570, Tagab-E-Munjan (505) and Asmar-Kamdesh (506) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  8. Topographic Map of Quadrangle 3566, Sang-Charak (501) and Sayghan-O-Kamard (502) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  9. Topographic Map of Quadrangle 3768 and 3668, Imam-Saheb (215), Rustaq (216), Baghlan (221), and Taloqan (222) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file report (OFR) number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The OFR numbers range in sequence from 1092 to 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS in cooperation with the

  10. Land-based lidar mapping: a new surveying technique to shed light on rapid topographic change

    USGS Publications Warehouse

    Collins, Brian D.; Kayen, Robert

    2006-01-01

    The rate of natural change in such dynamic environments as rivers and coastlines can sometimes overwhelm the monitoring capacity of conventional surveying methods. In response to this limitation, U.S. Geological Survey (USGS) scientists are pioneering new applications of light detection and ranging (lidar), a laser-based scanning technology that promises to greatly increase our ability to track rapid topographic changes and manage their impact on affected communities.

  11. South Tank Farm underground storage tank inspection using the topographical mapping system for radiological and hazardous environments

    SciTech Connect

    Armstrong, G.A.; Burks, B.L.; Hoesen, S.D. van

    1997-07-01

    During the winter of 1997 the Topographical Mapping System (TMS) for hazardous and radiological environments and the Interactive Computer-Enhanced Remote-Viewing System (ICERVS) were used to perform wall inspections on underground storage tanks (USTs) W5 and W6 of the South Tank Farm (STF) at Oak Ridge National Laboratory (ORNL). The TMS was designed for deployment in the USTs at the Hanford Site. Because of its modular design, the TMS was also deployable in the USTs at ORNL. The USTs at ORNL were built in the 1940s and have been used to store radioactive waste during the past 50 years. The tanks are constructed with an inner layer of Gunite{trademark} that has been spalling, leaving sections of the inner wall exposed. Attempts to quantify the depths of the spalling with video inspection have proven unsuccessful. The TMS surface-mapping campaign in the STF was initiated to determine the depths of cracks, crevices, and/or holes in the tank walls and to identify possible structural instabilities in the tanks. The development of the TMS and the ICERVS was initiated by DOE for the purpose of characterization and remediation of USTs at DOE sites across the country. DOE required a three-dimensional, topographical mapping system suitable for use in hazardous and radiological environments. The intended application is mapping the interiors of USTs as part of DOE`s waste characterization and remediation efforts, to obtain both baseline data on the content of the storage tank interiors and changes in the tank contents and levels brought about by waste remediation steps. Initially targeted for deployment at the Hanford Site, the TMS has been designed to be a self-contained, compact, and reconfigurable system that is capable of providing rapid variable-resolution mapping information in poorly characterized workspaces with a minimum of operator intervention.

  12. Can Self-Organizing Maps Accurately Predict Photometric Redshifts?

    NASA Astrophysics Data System (ADS)

    Way, M. J.; Klose, C. D.

    2012-03-01

    We present an unsupervised machine-learning approach that can be employed for estimating photometric redshifts. The proposed method is based on a vector quantization called the self-organizing-map (SOM) approach. A variety of photometrically derived input values were utilized from the Sloan Digital Sky Survey's main galaxy sample, luminous red galaxy, and quasar samples, along with the PHAT0 data set from the Photo-z Accuracy Testing project. Regression results obtained with this new approach were evaluated in terms of root-mean-square error (RMSE) to estimate the accuracy of the photometric redshift estimates. The results demonstrate competitive RMSE and outlier percentages when compared with several other popular approaches, such as artificial neural networks and Gaussian process regression. SOM RMSE results (using Δz = zphot - zspec) are 0.023 for the main galaxy sample, 0.027 for the luminous red galaxy sample, 0.418 for quasars, and 0.022 for PHAT0 synthetic data. The results demonstrate that there are nonunique solutions for estimating SOM RMSEs. Further research is needed in order to find more robust estimation techniques using SOMs, but the results herein are a positive indication of their capabilities when compared with other well-known methods.

  13. Quantification of Early Stages of Cortical Reorganization of the Topographic Map of V1 Following Retinal Lesions in Monkeys

    PubMed Central

    Botelho, Eliã P.; Ceriatte, Cecília; Soares, Juliana G.M.; Gattass, Ricardo; Fiorani, Mario

    2014-01-01

    We quantified the capacity for reorganization of the topographic representation of area V1 in adult monkeys. Bias-free automated mapping methods were used to delineate receptive fields (RFs) of an array of neuronal clusters prior to, and up to 6 h following retinal lesions. Monocular lesions caused a significant reorganization of the topographic map in this area, both inside and outside the cortical lesion projection zone (LPZ). Small flashed stimuli revealed responses up to 0.85 mm inside the boundaries of the LPZ, with RFs representing regions of undamaged retina immediately surrounding the lesion. In contrast, long moving bars that spanned the scotoma resulting from the lesion revealed responsive units up to 1.87 mm inside the LPZ, with RFs representing interpolated responses in this region. This reorganization is present immediately after monocular retinal lesioning. Both stimuli showed a similar and significant (5-fold) increase of the RF scatter in the LPZ, 0.56 mm (median), compared with the undamaged retina, 0.12 mm. Our results reveal an array of preexisting subthreshold functional connections of up to 2 mm in V1, which can be rapidly mobilized independently from the differential qualitative reorganization elicited by each stimulus. PMID:23010747

  14. AI-based technique for tracking chains of discontinuous symbols and its application to the analysis of topographic maps

    NASA Astrophysics Data System (ADS)

    Mecocci, Alessandro; Lilla, Massimiliano

    1994-12-01

    Automatic digitization of topographic maps is a very important task nowadays. Among the different elements of a topographic map discontinuous lines represent important information. Generally they are difficult to track because they show very large gaps, and abrupt direction changes. In this paper an architecture that automates the digitalization of discontinuous lines (dot-dot lines, dash-dot-dash lines, dash-asterisk lines, etc.) is presented. The tracking process must detect the elementary symbols and then concatenate these symbols into a significant chain that represents the line. The proposed architecture is composed of a common kernel, based on a suitable modification of the A* algorithm, that starts different auxiliary processes depending on the particular line to be tracked. Three auxiliary processes are considered: search strategy generation (SSG) which is responsible for the strategy used to scan the image pixels; low level symbol detection (LSD) which decides if a certain image region around the pixel selected by the SSG is an elementary symbol; cost evaluation (CE) which gives the quality of each symbol with respect to the global course of the line. The whole system has been tested on a 1:50.000 map furnished by the Istituto Geografico Militare Italiano (IGMI). The results were very good for different types of discontinuous lines. Over the whole map (i.e. about 80 Mbytes of digitized data) 95% of the elementary symbols of the lines have been correctly chained. The operator time required to correct misclassifications is a small part of the time needed to manually digitize the discontinuous lines.

  15. SRTM DTM vs. one created from 1/50.000 topographic maps: the case of Kos Island

    NASA Astrophysics Data System (ADS)

    Nikolakopoulos, Konstantinos; Vaiopoulos, Dimitris; Skianis, Georgios

    2005-10-01

    The Shuttle Radar Topography Mission (SRTM), used an Interferometric Synthetic Aperture Radar (IFSAR) instrument to produce a near-global digital elevation map of the earth's land surface with 16 m absolute vertical height accuracy at 30 meter postings. SRTM achieved the required interferometric baseline by extending a receive-only radar antenna on a 60 meter deployable mast from the shuttle payload bay. Continuous measurement of the interferometric baseline length, attitude, and position was required at the 2 mm, 9 arcsec, and 1 m (1.6 sigma) levels, respectively, in order to obtain the desired height accuracy. The collected data were used to generate a digital topographic map of 80 percent of Earth's land surface (everything between 60 degrees north and 56 degrees south latitude), with data points spaced every 1 arcsecond of latitude and longitude (approximately 30 meters). An SRTM 3-arc-second product (90m resolution) is available for the entire world. In this paper we compare a DTM created from SRTM data to a DTM created from 1/50.000 topographic maps. The area of study is Kos Island in the Aegean Sea. Since the SRTM elevation data are unedited, they contain occasional voids, or gaps, where the terrain lay in the radar beam's shadow or in areas of extremely low radar backscatter, such as sea, dams, lakes and virtually any water covered surface that are flat but they don't look so flat on SRTM tiles. We used different filters and masks in order to ameliorate the quality of the DEM. The first filter detected and removed the voids; a second one interpolated the missing values and then a mask was used in order to separate sea from land. We also created a DTM from digitized contours of 1/50.000 scale topographic maps and we used more than 1800 extra points in order to ameliorate the quality of this DTM around the coastline. We compared the two DTMs. All the results demonstrated that the SRTM DTM presents a very good accuracy.

  16. A statistical-topographic model for mapping climatological precipitation over mountainous terrain

    SciTech Connect

    Daly, C.; Neilson, R.P.; Phillips, D.L.

    1994-02-01

    The demand for climatological precipitation fields on a regular grid is growing dramatically as ecological and hydrological models become increasingly linked to geographic information systems that spatially represent and manipulate model output. This paper presents an analytical model that distributes point measurements of monthly and annual precipitation to regularly spaced grid cells in midlatitude regions. PRISM (Precipitation-elevation Regressions on Independent Slopes Model) brings a combination of climatological and statistical concepts to the analysis of orographic precipitation. Specifically, PRISM (1) uses a digital elevation model (DEM) to estimate the {open_quotes}orographic{close_quotes} elevations of precipitation stations; (2) uses the DEM and a windowing technique to group stations onto individual topographic facets; (3) estimates precipitation at a DEM grid cell through a regression of precipitation versus DEM elevation developed from stations on the cell`s topographic facet; and (4) when possible, calculates a prediction interval for the estimate, which is an approximation of the uncertainty involved. PRISM exhibited the lowest cross-validation bias and absolute error when compared to kriging, detrended kriging, and cokriging in the Willamette River basin, Oregon. PRISM was also applied to northern Oregon and to the entire western United States; detrended kriging and cokriging could not be used, because there was no overall relationship between elevation and precipitation. Cross-validation errors in these applications were confined to relatively low levels because PRISM continually adjusts its frame of reference by using localized precipitation-DEM elevation relationships. 39 refs., 9 figs., 5 tabs.

  17. Watershed boundaries and digital elevation model of Oklahoma derived from 1:100,000-scale digital topographic maps

    USGS Publications Warehouse

    Cederstrand, J.R.; Rea, A.H.

    1995-01-01

    This document provides a general description of the procedures used to develop the data sets included on this compact disc. This compact disc contains watershed boundaries for Oklahoma, a digital elevation model, and other data sets derived from the digital elevation model. The digital elevation model was produced using the ANUDEM software package, written by Michael Hutchinson and licensed from the Centre for Resource and Environmental Studies at The Australian National University. Elevation data (hypsography) and streams (hydrography) from digital versions of the U.S. Geological Survey 1:100,000-scale topographic maps were used by the ANUDEM package to produce a hydrologically conditioned digital elevation model with a 60-meter cell size. This digital elevation model is well suited for drainage-basin delineation using automated techniques. Additional data sets include flow-direction, flow-accumulation, and shaded-relief grids, all derived from the digital elevation model, and the hydrography data set used in producing the digital elevation model. The watershed boundaries derived from the digital elevation model have been edited to be consistent with contours and streams from the U.S. Geological Survey 1:100,000-scale topographic maps. The watershed data set includes boundaries for 11-digit Hydrologic Unit Codes (watersheds) within Oklahoma, and 8-digit Hydrologic Unit Codes (cataloging units) outside Oklahoma. Cataloging-unit boundaries based on 1:250,000-scale maps outside Oklahoma for the Arkansas, Red, and White River basins are included. The other data sets cover Oklahoma, and where available, portions of 1:100,000-scale quadrangles adjoining Oklahoma.

  18. Satellite-based damage mapping following the 2006 Indonesia earthquake—How accurate was it?

    NASA Astrophysics Data System (ADS)

    Kerle, Norman

    2010-12-01

    The Yogyakarta area in Indonesia suffered a devastating earthquake on 27 May 2006. There was an immediate international response, and the International Charter "Space and Major Disasters" was activated, leading to a rapid production of image-based damage maps and other assistance. Most of the acquired images were processed by UNOSAT and DLR-ZKI, while substantial damage mapping also occurred on the ground. This paper assesses the accuracy and completeness of the damage maps produced based on Charter data, using ground damage information collected during an extensive survey by Yogyakarta's Gadjah Mada University in the weeks following the earthquake and that has recently become available. More than 54,000 buildings or their remains were surveyed, resulting in an exceptional validation database. The UNOSAT damage maps outlining clusters of severe damage are very accurate, while earlier, more detailed results underestimated damage and missed larger areas. Damage maps produced by DLR-ZKI, using a damage-grid approach, were found to underestimate the extent and severity of the devastation. Both mapping results also suffer from limited image coverage and extensive cloud contamination. The ground mapping gives a more accurate picture of the extent of the damage, but also illustrates the challenge of mapping a vast area. The paper concludes with a discussion on ways to improve Charter-based damage maps by integration of local knowledge, and to create a wider impact through generation of customised mapping products using web map services.

  19. True-3D Accentuating of Grids and Streets in Urban Topographic Maps Enhances Human Object Location Memory

    PubMed Central

    Edler, Dennis; Bestgen, Anne-Kathrin; Kuchinke, Lars; Dickmann, Frank

    2015-01-01

    Cognitive representations of learned map information are subject to systematic distortion errors. Map elements that divide a map surface into regions, such as content-related linear symbols (e.g. streets, rivers, railway systems) or additional artificial layers (coordinate grids), provide an orientation pattern that can help users to reduce distortions in their mental representations. In recent years, the television industry has started to establish True-3D (autostereoscopic) displays as mass media. These modern displays make it possible to watch dynamic and static images including depth illusions without additional devices, such as 3D glasses. In these images, visual details can be distributed over different positions along the depth axis. Some empirical studies of vision research provided first evidence that 3D stereoscopic content attracts higher attention and is processed faster. So far, the impact of True-3D accentuating has not yet been explored concerning spatial memory tasks and cartography. This paper reports the results of two empirical studies that focus on investigations whether True-3D accentuating of artificial, regular overlaying line features (i.e. grids) and content-related, irregular line features (i.e. highways and main streets) in official urban topographic maps (scale 1/10,000) further improves human object location memory performance. The memory performance is measured as both the percentage of correctly recalled object locations (hit rate) and the mean distances of correctly recalled objects (spatial accuracy). It is shown that the True-3D accentuating of grids (depth offset: 5 cm) significantly enhances the spatial accuracy of recalled map object locations, whereas the True-3D emphasis of streets significantly improves the hit rate of recalled map object locations. These results show the potential of True-3D displays for an improvement of the cognitive representation of learned cartographic information. PMID:25679208

  20. True-3D accentuating of grids and streets in urban topographic maps enhances human object location memory.

    PubMed

    Edler, Dennis; Bestgen, Anne-Kathrin; Kuchinke, Lars; Dickmann, Frank

    2015-01-01

    Cognitive representations of learned map information are subject to systematic distortion errors. Map elements that divide a map surface into regions, such as content-related linear symbols (e.g. streets, rivers, railway systems) or additional artificial layers (coordinate grids), provide an orientation pattern that can help users to reduce distortions in their mental representations. In recent years, the television industry has started to establish True-3D (autostereoscopic) displays as mass media. These modern displays make it possible to watch dynamic and static images including depth illusions without additional devices, such as 3D glasses. In these images, visual details can be distributed over different positions along the depth axis. Some empirical studies of vision research provided first evidence that 3D stereoscopic content attracts higher attention and is processed faster. So far, the impact of True-3D accentuating has not yet been explored concerning spatial memory tasks and cartography. This paper reports the results of two empirical studies that focus on investigations whether True-3D accentuating of artificial, regular overlaying line features (i.e. grids) and content-related, irregular line features (i.e. highways and main streets) in official urban topographic maps (scale 1/10,000) further improves human object location memory performance. The memory performance is measured as both the percentage of correctly recalled object locations (hit rate) and the mean distances of correctly recalled objects (spatial accuracy). It is shown that the True-3D accentuating of grids (depth offset: 5 cm) significantly enhances the spatial accuracy of recalled map object locations, whereas the True-3D emphasis of streets significantly improves the hit rate of recalled map object locations. These results show the potential of True-3D displays for an improvement of the cognitive representation of learned cartographic information. PMID:25679208

  1. Evaluation of morphometric parameters of drainage networks derived from topographic maps and DEM in point of floods

    NASA Astrophysics Data System (ADS)

    Ozdemir, Hasan; Bird, Deanne

    2009-02-01

    An evaluation of morphometric parameters of two drainage networks derived from different sources was done to determine the influence of sub-basins to flooding on the main channel in the Havran River basin (Balıkesir-Turkey). Drainage networks for the sub-basins were derived from both topographic maps scaled 1:25.000 and a 10-m resolution digital elevation model (DEM) using geographic information systems (GIS). Blue lines, representing fluvial channels on the topographic maps were accepted as a drainage network, which does not depict all exterior links in the basin. The second drainage network was extracted from the DEM using minimum accumulation area threshold to include all exterior links. Morphometric parameters were applied to the two types of drainage networks at sub-basin levels. These parameters were used to assess the influence of the sub-basins on the main channel with respect to flooding. The results show that the drainage network of sub-basin 4—where a dam was constructed on its outlet to mitigate potential floods—has a lower influence morphometrically to produce probable floods on the main channel than that of sub-basins 1, 3, and 5. The construction of the dam will help reduce flooding on the main channel from sub-basin 4 but it will not prevent potential flooding from sub-basin 1, 3 and 5, which join the main channel downstream of sub-basin 4. Therefore, flood mitigation efforts should be considered in order to protect the settlement and agricultural lands on the floodplain downstream of the dam. In order to increase our understanding of flood hazards, and to determine appropriate mitigation solutions, drainage morphometry research should be included as an essential component to hydrologic studies.

  2. Mapping forested wetlands in the Great Zhan River Basin through integrating optical, radar, and topographical data classification techniques.

    PubMed

    Na, X D; Zang, S Y; Wu, C S; Li, W L

    2015-11-01

    Knowledge of the spatial extent of forested wetlands is essential to many studies including wetland functioning assessment, greenhouse gas flux estimation, and wildlife suitable habitat identification. For discriminating forested wetlands from their adjacent land cover types, researchers have resorted to image analysis techniques applied to numerous remotely sensed data. While with some success, there is still no consensus on the optimal approaches for mapping forested wetlands. To address this problem, we examined two machine learning approaches, random forest (RF) and K-nearest neighbor (KNN) algorithms, and applied these two approaches to the framework of pixel-based and object-based classifications. The RF and KNN algorithms were constructed using predictors derived from Landsat 8 imagery, Radarsat-2 advanced synthetic aperture radar (SAR), and topographical indices. The results show that the objected-based classifications performed better than per-pixel classifications using the same algorithm (RF) in terms of overall accuracy and the difference of their kappa coefficients are statistically significant (p<0.01). There were noticeably omissions for forested and herbaceous wetlands based on the per-pixel classifications using the RF algorithm. As for the object-based image analysis, there were also statistically significant differences (p<0.01) of Kappa coefficient between results performed based on RF and KNN algorithms. The object-based classification using RF provided a more visually adequate distribution of interested land cover types, while the object classifications based on the KNN algorithm showed noticeably commissions for forested wetlands and omissions for agriculture land. This research proves that the object-based classification with RF using optical, radar, and topographical data improved the mapping accuracy of land covers and provided a feasible approach to discriminate the forested wetlands from the other land cover types in forestry area. PMID

  3. The digital global geologic map of Mars: chronostratigraphic ages, topographic and crater morphologic characteristics, and updated resurfacing history

    USGS Publications Warehouse

    Tanaka, K.L.; Robbins, S.J.; Fortezzo, C.M.; Skinner, J.A., Jr.; Hare, T.M.

    2014-01-01

    A new global geologic map of Mars has been completed in a digital, geographic information system (GIS) format using geospatially controlled altimetry and image data sets. The map reconstructs the geologic history of Mars, which includes many new findings collated in the quarter century since the previous, Viking-based global maps were published, as well as other discoveries that were made during the course of the mapping using new data sets. The technical approach enabled consistent and regulated mapping that is appropriate not only for the map's 1:20,000,000 scale but also for its widespread use by diverse audiences. Each geologic unit outcrop includes basic attributes regarding identity, location, area, crater densities, and chronostratigraphic age. In turn, units are grouped by geographic and lithologic types, which provide synoptic global views of material ages and resurfacing character for the Noachian, Hesperian, and Amazonian periods. As a consequence of more precise and better quality topographic and morphologic data and more complete crater-density dating, our statistical comparisons identify significant refinements for how Martian geologic terrains are characterized. Unit groups show trends in mean elevation and slope that relate to geographic occurrence and geologic origin. In comparison with the previous global geologic map series based on Viking data, the new mapping consists of half the number of units due to simpler, more conservative and globally based approaches to discriminating units. In particular, Noachian highland surfaces overall have high percentages of their areas now dated as an epoch older than in the Viking mapping. Minimally eroded (i.e., pristine) impact craters ≥3 km in diameter occur in greater proportion on Hesperian surfaces. This observation contrasts with a deficit of similarly sized craters on heavily cratered and otherwise degraded Noachian terrain as well as on young Amazonian surfaces. We interpret these as reflecting the

  4. The digital global geologic map of Mars: Chronostratigraphic ages, topographic and crater morphologic characteristics, and updated resurfacing history

    NASA Astrophysics Data System (ADS)

    Tanaka, K. L.; Robbins, S. J.; Fortezzo, C. M.; Skinner, J. A.; Hare, T. M.

    2014-05-01

    A new global geologic map of Mars has been completed in a digital, geographic information system (GIS) format using geospatially controlled altimetry and image data sets. The map reconstructs the geologic history of Mars, which includes many new findings collated in the quarter century since the previous, Viking-based global maps were published, as well as other discoveries that were made during the course of the mapping using new data sets. The technical approach enabled consistent and regulated mapping that is appropriate not only for the map's 1:20,000,000 scale but also for its widespread use by diverse audiences. Each geologic unit outcrop includes basic attributes regarding identity, location, area, crater densities, and chronostratigraphic age. In turn, units are grouped by geographic and lithologic types, which provide synoptic global views of material ages and resurfacing character for the Noachian, Hesperian, and Amazonian periods. As a consequence of more precise and better quality topographic and morphologic data and more complete crater-density dating, our statistical comparisons identify significant refinements for how Martian geologic terrains are characterized. Unit groups show trends in mean elevation and slope that relate to geographic occurrence and geologic origin. In comparison with the previous global geologic map series based on Viking data, the new mapping consists of half the number of units due to simpler, more conservative and globally based approaches to discriminating units. In particular, Noachian highland surfaces overall have high percentages of their areas now dated as an epoch older than in the Viking mapping. Minimally eroded (i.e., pristine) impact craters ≥3 km in diameter occur in greater proportion on Hesperian surfaces. This observation contrasts with a deficit of similarly sized craters on heavily cratered and otherwise degraded Noachian terrain as well as on young Amazonian surfaces. We interpret these as reflecting the

  5. Assessment of drainage network extractions in a low-relief area of the Cuvelai Basin (Namibia) from multiple sources: LiDAR, topographic maps, and digital aerial orthophotographs

    NASA Astrophysics Data System (ADS)

    Persendt, F. C.; Gomez, C.

    2016-05-01

    Accurate delineation of drainage networks (DNs) is crucial for hydrological or hydraulic modelling, and the comprehension of fluvial processes. This task presents challenging aspects in complex lowland terrains with subtle relief and particularly for data poor-areas like the Cuvelai river basin (CRB), Namibia, where the present study takes place. In the CRB standard methods of drainage network extraction from low resolution gridded digital elevation models (DEMs) are unsuitable, hence airborne Light Detection and Ranging (LiDAR) solutions have been utilized. However, LiDAR also presents challenges to large areal applications, especially with a surface roughness exceeding the capacity of numerous algorithms. Indeed, LiDAR-based DEMs (2 and 50 m resolutions) need to be hydrologically corrected and smoothed to enable the extraction of scale-relevant geomorphologic features such as DNs. In the present contribution, channels from topographic maps (blue lines) were compared to those from hydrologically corrected and uncorrected LiDAR DEMs, heads-up digitized channels from high-resolution digital aerial orthophotographs, field-mapped channels and auxiliary data. The 'maximum gradient deterministic eight (D8)' GIS algorithm was applied to the corrected and uncorrected LiDAR DEMs using two network extraction methods: area threshold support and curvature/drop analysis. Different progressive flow accumulation threshold values (12) were used to delineate channels with these methods. Validation was performed between the field-mapped channels, the modelled channels and those derived from multiple sources. Additionally, spatial and quantitative analyses were performed on geomorphologic parameters and indices. The results have shown that hydrologically corrected LiDAR DEMs offer useful details for identifying low order stream segments in headwaters, while blue lines derived from the national hydrography datasets for watersheds, located in elevated and low-lying areas of the study

  6. Evaluation of the altimetry from SRTM-3 and planimetry from high-resolution PALSAR FBD data for semi-detailed topographic mapping in the Amazon Region.

    PubMed

    Rodrigues, Thiago G; Paradella, Waldir R; Oliveira, Cleber G

    2011-09-01

    The Brazilian Amazon has a deficit of 35% of coverage regarding topographic mapping at semi-detailed (1:100,000) scale. This paper presents an alternative to overcome this scenario using a combination of planialtimetric information from two orbital SAR (Synthetic Aperture Radar) missions. The altimetry was acquired from Shuttle Radar Topography Mission (SRTM), while the planimetry was provided from Fine Beam Dual (FBD) images of the Phased Array L-band Synthetic Aperture Radar (PALSAR) sensor. The research was carried out in the mountainous area of the Serra dos Carajás (Pará State), located on the Amazon region. The quality of the orbital topographic information was evaluated regarding precise planialtimetric measurements acquired from Global Positioning System (GPS) field campaigns. The evaluations were performed following two approaches: (1) the use of Root Mean Square Error (RMSE) and (2) tendency and precision hypothesis tests. The investigation has shown that the planialtimetric quality of the orbital products fulfilled the Brazilian Map Accuracy Standards requirements for 1:100,000 A Class map. Thus, the use of combination of information provided by PALSAR and SRTM-3 data can be considered a promising alternative for production and update of semi-detailed topographic mapping in similar environments of the Amazon region, where topographic information is lacking or presents low quality. PMID:21861043

  7. Application of PALSAR-2 remote sensing data for structural geology and topographic mapping in Kelantan river basin, Malaysia

    NASA Astrophysics Data System (ADS)

    Beiranvand Pour, Amin; Hashim, Mazlan

    2016-06-01

    Natural hazards of geological origin are one of major problem during heavy monsoons rainfall in Kelantan state, peninsular Malaysia. Several landslides occur in this region are obviously connected to geological and topographical features, every year. Satellite synthetic aperture radar (SAR) data are particularly applicable for detection of geological structural and topographical features in tropical conditions. In this study, Phased Array type L-band Synthetic Aperture Radar (PALSAR-2), remote sensing data were used to identify high potential risk and susceptible zones for landslide in the Kelantan river basin. Adaptive Local Sigma filter was selected and applied to accomplish speckle reduction and preserving both edges and features in PALSAR-2 fine mode observation images. Different polarization images were integrated to enhance geological structures. Additionally, directional filters were applied to the PALSAR-2 Local Sigma resultant image for edge enhancement and detailed identification of linear features. Several faults, drainage patterns and lithological contact layers were identified at regional scale. In order to assess the results, fieldwork and GPS survey were conducted in the landslide affected zones in the Kelantan river basin. Results demonstrate the most of the landslides were associated with N-S, NNW-SSE and NE-SW trending faults, angulate drainage pattern and metamorphic and Quaternary units. Consequently, geologic structural map were produced for Kelantan river basin using recent PALSAR-2 data, which could be broadly applicable for landslide hazard assessment and delineation of high potential risk and susceptible areas. Landslide mitigation programmes could be conducted in the landslide recurrence regions for reducing catastrophes leading to economic losses and death.

  8. Fast and Accurate Construction of Ultra-Dense Consensus Genetic Maps Using Evolution Strategy Optimization

    PubMed Central

    Mester, David; Ronin, Yefim; Schnable, Patrick; Aluru, Srinivas; Korol, Abraham

    2015-01-01

    Our aim was to develop a fast and accurate algorithm for constructing consensus genetic maps for chip-based SNP genotyping data with a high proportion of shared markers between mapping populations. Chip-based genotyping of SNP markers allows producing high-density genetic maps with a relatively standardized set of marker loci for different mapping populations. The availability of a standard high-throughput mapping platform simplifies consensus analysis by ignoring unique markers at the stage of consensus mapping thereby reducing mathematical complicity of the problem and in turn analyzing bigger size mapping data using global optimization criteria instead of local ones. Our three-phase analytical scheme includes automatic selection of ~100-300 of the most informative (resolvable by recombination) markers per linkage group, building a stable skeletal marker order for each data set and its verification using jackknife re-sampling, and consensus mapping analysis based on global optimization criterion. A novel Evolution Strategy optimization algorithm with a global optimization criterion presented in this paper is able to generate high quality, ultra-dense consensus maps, with many thousands of markers per genome. This algorithm utilizes "potentially good orders" in the initial solution and in the new mutation procedures that generate trial solutions, enabling to obtain a consensus order in reasonable time. The developed algorithm, tested on a wide range of simulated data and real world data (Arabidopsis), outperformed two tested state-of-the-art algorithms by mapping accuracy and computation time. PMID:25867943

  9. Morphometric analysis of the Koros drainage basin (Hungary/Romania) using historical topographic maps

    NASA Astrophysics Data System (ADS)

    Petrovszki, J.

    2009-04-01

    The Körös River drainage basin is located in the eastern part of the Great Hungarian Plain, west of the Apuseni Mts., in the middle of the Pannonian Basin. The channels of the river and its tributaries are mostly meandering. The channel sinuosity of this river system is analyzed in order to draw conclusions on the neotectonic activity of this area. The meandering rivers can demonstrate changes, which occurred recently, and cannot be seen with other methods. The changing sinuosity indicates the location of the vertical movements of the surface. The sinuosity calculations were made on the natural, uncontrolled riverbeds. These beds were digitized from the maps of the Second Military Survey of the Habsburg Empire, which were measured before or during river control implementation. Digitized features were made on the geo-referred maps, which are in the Hungarian National Grid (EOV) coordinate system. The estimated accuracy of the map sheets to the modern system is 50-100 m, but the accuracy in Hungary remains under 30 m. In the study area, we identified several points of sinuosity change. To prove, that these are of neotectonic origin, seismic sections crossing the study area, were also analyzed. Five fault lines are indicated to be neotectonically active according to the river planform changes. Activity of two of these five faults, and the subsidence in-between them caused the formation of the Nagy-Sárrét marshland. A Romanian river section, characterized by anastomosed planform, instead of meandering, indicates recent activity of another fault.

  10. A rapid topographic mapping and eye alignment method using optical imaging in Macaque visual cortex

    PubMed Central

    HD, Lu; G, Chen; DY, Ts’o; AW, Roe

    2009-01-01

    In optical imaging experiments, it is often advantageous to map the field of view and to converge the eyes without electrophysiological recording. This occurs when limited space precludes placement of an electrode or in chronic optical chambers in which one may not want to introduce an electrode each session or for determining eye position in studies of ocular disparity response in visual cortex of anesthetized animals. For these purposes, we have developed a spot imaging method that can be conducted rapidly and repeatedly throughout an experiment. Using small 0.2° – 0.5° spots, the extent of the imaged field of view is mapped by imaging cortical response to single spots, placed at different positions (0.2° steps) in either the horizontal or vertical axes. By shifting the relative positions of two spots, one presented to each eye, eye convergence can be assessed to within 0.1° resolution. Once appropriate eye alignment is determined, stimuli for further optical imaging procedures (e.g. imaging random dot stimuli for study of disparity responses) can then be confidently placed. This procedure can be quickly repeated throughout the experiment to ensure maintained eye alignment. PMID:19013530

  11. Integrating Physical and Topographic Information Into a Fuzzy Scheme to Map Flooded Area by SAR

    PubMed Central

    Pierdicca, Nazzareno; Chini, Marco; Pulvirenti, Luca; Macina, Flavia

    2008-01-01

    A flood mapping procedure based on a fuzzy sets theory has been developed. The method is based on the integration of Synthetic Aperture Radar (SAR) measurements with additional data on the inundated area, such as a land cover map and a digital elevation model (DEM). The information on land cover has allowed us to account for both specular reflection, typical of open water, and double bounce backscattering, typical of forested and urban areas. DEM has been exploited to include simple hydraulic considerations on the dependence of inundation probability on surface characteristics. Contextual information has been taken into account too. The proposed algorithm has been tested on a flood occurred in Italy on November 1994. A pair of ERS-1 images, collected before and after (three days later) the flood, has been used. The results have been compared with the data provided by a ground survey carried out when the flood reached its maximum extension. Despite the temporal mismatch between the survey and the post-inundation SAR image, the comparison has yielded encouraging results, with the 87% of the pixels correctly classified as inundated.

  12. A Mars' Year of Topographic Mapping With The Mars Orbiter Laser Altimeter

    NASA Technical Reports Server (NTRS)

    Smith, David E.; Zuber, Maria T.

    2001-01-01

    Since the end of February 1999 the Mars Orbiter Laser Altimeter (MOLA) has been mapping the planet continuously except for a 2 month period around solar conjunction in June 2000. At the end of January 2001 the Mars Global Surveyor Spacecraft (MGS) had completed its prime Mission, one Mars year of observing the planet, and begun the Extended Mission of slightly more than 14 months. MOLA will had acquired over 530 million altimetric measurements by early 2001, and continued to work perfectly. During the Extended Mission the main objective for MOLA will be observations of the seasonal variations in the locations and altitudes of clouds, the changes in the elevations of the polar icecaps due to the deposition and sublimation Of CO2, as well as supporting NASA's search for suitable future landing sites.

  13. Topographic mapping of subsurface fluorescent structures in tissue using multiwavelength excitation

    PubMed Central

    Kim, Anthony; Roy, Mathieu; Dadani, Farhan N.; Wilson, Brian C.

    2010-01-01

    Different colors of visible light penetrate to varying depths in tissue due to the wavelength dependence of tissue optical absorption and elastic scattering. We exploit this to map the contour of the closest surface of a buried fluorescent object. This uses a novel algorithm based on the diffusion theory description of light propagation in tissue at each excitation wavelength to derive metrics that define the depth of the top surface of the object. The algorithm was validated using a tissue-simulating phantom. It was then demonstrated in vivo by subsurface brain tumor topography in a rodent model, using the fluorescence signal from protoporphyrin IX that is preferentially synthesized within malignant cells following systemic application of aminolevulinic acid. Comparisons to histomorphometry in the brain post mortem show the spatial accuracy of the technique. This method has potential for fluorescence image-guided tumor surgery, as well as other biomedical and nonbiological applications in subsurface sensing. PMID:21198200

  14. WM-DOVA maps for accurate polyp highlighting in colonoscopy: Validation vs. saliency maps from physicians.

    PubMed

    Bernal, Jorge; Sánchez, F Javier; Fernández-Esparrach, Gloria; Gil, Debora; Rodríguez, Cristina; Vilariño, Fernando

    2015-07-01

    We introduce in this paper a novel polyp localization method for colonoscopy videos. Our method is based on a model of appearance for polyps which defines polyp boundaries in terms of valley information. We propose the integration of valley information in a robust way fostering complete, concave and continuous boundaries typically associated to polyps. This integration is done by using a window of radial sectors which accumulate valley information to create WM-DOVA (Window Median Depth of Valleys Accumulation) energy maps related with the likelihood of polyp presence. We perform a double validation of our maps, which include the introduction of two new databases, including the first, up to our knowledge, fully annotated database with clinical metadata associated. First we assess that the highest value corresponds with the location of the polyp in the image. Second, we show that WM-DOVA energy maps can be comparable with saliency maps obtained from physicians' fixations obtained via an eye-tracker. Finally, we prove that our method outperforms state-of-the-art computational saliency results. Our method shows good performance, particularly for small polyps which are reported to be the main sources of polyp miss-rate, which indicates the potential applicability of our method in clinical practice. PMID:25863519

  15. VERITAS: A Mission Concept for the High Resolution Topographic Mapping and Imaging of Venus

    NASA Astrophysics Data System (ADS)

    Hensley, S.; Smrekar, S. E.; Pollard, B.

    2012-12-01

    Magellan, a NASA mission to Venus in the early 1990's, mapped nearly the entire surface of Venus with an S-band (12 cm) synthetic aperture radar and microwave radiometer and made radar altimeter measurements of the topography. These measurements revolutionized our understanding of the geomorphology, geology and geophysical processes that have shaped the evolution of the surface of Venus. The Magellan spacecraft had an elliptical orbit with an apoapsis of approximately 8000 km and a periapsis of 257 km and an orbital inclination of 86°. In this way the radar was able to collect long strips of data approximately 10000 km in length running north to south with altitudes varying from 3000 km to 257 km. During the remainder of the orbit the collected data was down linked to earth. The SAR mode operated in burst mode fashion whereby it transmitted a small string of pulses up to a couple of hundred pulses in length followed by a quiescent period when the radar ceased transmission and allowed interleaved operation of the altimeter and radiometer modes. This mode of operation allowed for a significant reduction in downlinked SAR imaging data at the expense of azimuth (i.e. along-track) resolution. However, the lack of finer resolution imagery and topography of the surface than that obtained by the Magellan mission has hampered the definitive answer to key questions concerning the processes and evolution of the surface of Venus. The Venus Emissivity, Radio Science, InSAR Topography And Spectroscopy (VERITAS) Mission is a proposed mission to Venus designed to obtain high resolution imagery and topography of the surface using an X-band radar configured as a single pass radar interferometer coupled with a multispectral NIR emissivity mapping capability. VERITAS would map surface topography with a spatial resolution of 250 m and 5 m vertical accuracy and generate radar imagery with 30 m spatial resolution. These capabilities represent an order of magnitude or better improvement

  16. Learning the Structure of High-Dimensional Manifolds with Self-Organizing Maps for Accurate Information Extraction

    NASA Astrophysics Data System (ADS)

    Zhang, Lili

    This work aims to improve the capability of accurate information extraction from high-dimensional data, with a specific neural learning paradigm, the Self-Organizing Map (SOM). The SOM is an unsupervised learning algorithm that can faithfully sense the manifold structure and support supervised learning of relevant information from the data. Yet open problems regarding SOM learning exist. We focus on the following two issues. (1) Evaluation of topology preservation. Topology preservation is essential for SOMs in faithful representation of manifold structure. However, in reality, topology violations are not unusual, especially when the data have complicated structure. Measures capable of accurately quantifying and informatively expressing topology violations are lacking. One contribution of this work is a new measure, the Weighted Differential Topographic Function (WDTF), which differentiates an existing measure, the Topographic Function (TF), and incorporates detailed data distribution as an importance weighting of violations to distinguish severe violations from insignificant ones. Another contribution is an interactive visual tool, TopoView, which facilitates the visual inspection of violations on the SOM lattice. We show the effectiveness of the combined use of the WDTF and TopoView through a simple two-dimensional data set and two hyperspectral images. (2) Learning multiple latent variables from high-dimensional data. We use an existing two-layer SOM-hybrid supervised architecture, which captures the manifold structure in its SOM hidden layer, and then, uses its output layer to perform the supervised learning of latent variables. In the customary way, the output layer only uses the strongest output of the SOM neurons. This severely limits the learning capability. We allow multiple, k, strongest responses of the SOM neurons for the supervised learning. Moreover, the fact that different latent variables can be best learned with different values of k motivates a

  17. MOSAIK: a hash-based algorithm for accurate next-generation sequencing short-read mapping.

    PubMed

    Lee, Wan-Ping; Stromberg, Michael P; Ward, Alistair; Stewart, Chip; Garrison, Erik P; Marth, Gabor T

    2014-01-01

    MOSAIK is a stable, sensitive and open-source program for mapping second and third-generation sequencing reads to a reference genome. Uniquely among current mapping tools, MOSAIK can align reads generated by all the major sequencing technologies, including Illumina, Applied Biosystems SOLiD, Roche 454, Ion Torrent and Pacific BioSciences SMRT. Indeed, MOSAIK was the only aligner to provide consistent mappings for all the generated data (sequencing technologies, low-coverage and exome) in the 1000 Genomes Project. To provide highly accurate alignments, MOSAIK employs a hash clustering strategy coupled with the Smith-Waterman algorithm. This method is well-suited to capture mismatches as well as short insertions and deletions. To support the growing interest in larger structural variant (SV) discovery, MOSAIK provides explicit support for handling known-sequence SVs, e.g. mobile element insertions (MEIs) as well as generating outputs tailored to aid in SV discovery. All variant discovery benefits from an accurate description of the read placement confidence. To this end, MOSAIK uses a neural-network based training scheme to provide well-calibrated mapping quality scores, demonstrated by a correlation coefficient between MOSAIK assigned and actual mapping qualities greater than 0.98. In order to ensure that studies of any genome are supported, a training pipeline is provided to ensure optimal mapping quality scores for the genome under investigation. MOSAIK is multi-threaded, open source, and incorporated into our command and pipeline launcher system GKNO (http://gkno.me). PMID:24599324

  18. A digital version of the 1970 U.S. Geological Survey topographic map of the San Francisco Bay region, three sheets, 1:125,000

    USGS Publications Warehouse

    Aitken, Douglas S.

    1997-01-01

    This Open-File report is a digital topographic map database. It contains a digital version of the 1970 U.S. Geological Survey topographic map of the San Francisco Bay Region (3 sheets), at a scale of 1:125,000. These ARC/INFO coverages are in vector format. The vectorization process has distorted characters representing letters and numbers, as well as some road and other symbols, making them difficult to read in some instances. This pamphlet serves to introduce and describe the digital data. There is no paper map included in the Open-File report. The content and character of the database and methods of obtaining it are described herein.

  19. Laser electro-optic system for rapid three-dimensional /3-D/ topographic mapping of surfaces

    NASA Technical Reports Server (NTRS)

    Altschuler, M. D.; Altschuler, B. R.; Taboada, J.

    1981-01-01

    It is pointed out that the generic utility of a robot in a factory/assembly environment could be substantially enhanced by providing a vision capability to the robot. A standard videocamera for robot vision provides a two-dimensional image which contains insufficient information for a detailed three-dimensional reconstruction of an object. Approaches which supply the additional information needed for the three-dimensional mapping of objects with complex surface shapes are briefly considered and a description is presented of a laser-based system which can provide three-dimensional vision to a robot. The system consists of a laser beam array generator, an optical image recorder, and software for controlling the required operations. The projection of a laser beam array onto a surface produces a dot pattern image which is viewed from one or more suitable perspectives. Attention is given to the mathematical method employed, the space coding technique, the approaches used for obtaining the transformation parameters, the optics for laser beam array generation, the hardware for beam array coding, and aspects of image acquisition.

  20. Topographical Mapping of the Rainbow Trout (Oncorhynchus mykiss) Microbiome Reveals a Diverse Bacterial Community with Antifungal Properties in the Skin.

    PubMed

    Lowrey, Liam; Woodhams, Douglas C; Tacchi, Luca; Salinas, Irene

    2015-10-01

    The mucosal surfaces of wild and farmed aquatic vertebrates face the threat of many aquatic pathogens, including fungi. These surfaces are colonized by diverse symbiotic bacterial communities that may contribute to fight infection. Whereas the gut microbiome of teleosts has been extensively studied using pyrosequencing, this tool has rarely been employed to study the compositions of the bacterial communities present on other teleost mucosal surfaces. Here we provide a topographical map of the mucosal microbiome of an aquatic vertebrate, the rainbow trout (Oncorhynchus mykiss). Using 16S rRNA pyrosequencing, we revealed novel bacterial diversity at each of the five body sites sampled and showed that body site is a strong predictor of community composition. The skin exhibited the highest diversity, followed by the olfactory organ, gills, and gut. Flectobacillus was highly represented within skin and gill communities. Principal coordinate analysis and plots revealed clustering of external sites apart from internal sites. A highly diverse community was present within the epithelium, as demonstrated by confocal microscopy and pyrosequencing. Using in vitro assays, we demonstrated that two Arthrobacter sp. skin isolates, a Psychrobacter sp. strain, and a combined skin aerobic bacterial sample inhibit the growth of Saprolegnia australis and Mucor hiemalis, two important aquatic fungal pathogens. These results underscore the importance of symbiotic bacterial communities of fish and their potential role for the control of aquatic fungal diseases. PMID:26209676

  1. Topographical Mapping of the Rainbow Trout (Oncorhynchus mykiss) Microbiome Reveals a Diverse Bacterial Community with Antifungal Properties in the Skin

    PubMed Central

    Lowrey, Liam; Woodhams, Douglas C.; Tacchi, Luca

    2015-01-01

    The mucosal surfaces of wild and farmed aquatic vertebrates face the threat of many aquatic pathogens, including fungi. These surfaces are colonized by diverse symbiotic bacterial communities that may contribute to fight infection. Whereas the gut microbiome of teleosts has been extensively studied using pyrosequencing, this tool has rarely been employed to study the compositions of the bacterial communities present on other teleost mucosal surfaces. Here we provide a topographical map of the mucosal microbiome of an aquatic vertebrate, the rainbow trout (Oncorhynchus mykiss). Using 16S rRNA pyrosequencing, we revealed novel bacterial diversity at each of the five body sites sampled and showed that body site is a strong predictor of community composition. The skin exhibited the highest diversity, followed by the olfactory organ, gills, and gut. Flectobacillus was highly represented within skin and gill communities. Principal coordinate analysis and plots revealed clustering of external sites apart from internal sites. A highly diverse community was present within the epithelium, as demonstrated by confocal microscopy and pyrosequencing. Using in vitro assays, we demonstrated that two Arthrobacter sp. skin isolates, a Psychrobacter sp. strain, and a combined skin aerobic bacterial sample inhibit the growth of Saprolegnia australis and Mucor hiemalis, two important aquatic fungal pathogens. These results underscore the importance of symbiotic bacterial communities of fish and their potential role for the control of aquatic fungal diseases. PMID:26209676

  2. Simultaneous Multiple Footprint and Multiple Field of View LiDAR for Submerged Topographic Mapping (Invited)

    NASA Astrophysics Data System (ADS)

    Wright, C. W.

    2013-12-01

    Charles Wayne Wright USGS, Coastal and Marine Science Center St. Petersburg, Fla. The Experimental Advanced Research LiDAR[a] (EAARL) has been designed to map sub aerial and submerged topography in and near shallow water environments. The system optically divides each 532 nanometer, 700 picosecond 420 uJ laser pulse into three distinct and divergent 133 uJ pulsed 1 milliradian beamlets which travel to the surface environment where they illuminate three distinct surface spots approximately 30cm in diameter and 1.3 meters apart from a nominal flight altitude of 300 meters. The system incorporates three spatially separated logarithmic response photomultiplier tube detectors coaligned with each of the 133 uJ laser beamlets. Each of the 133 uJ detectors views a 2 milliradian (2mr) field-of-view enabling fine scale near beam-C like time resolved backscattered waveforms. These three 2mr waveforms provide independent fine scale elevation measurement and water column discrimination over the range to zero to approximately 5 meters of water depth. The 2mr channels provide good surface reflection to bottom reflection resolution even over the very short time intervals associated with shallow water on the order of 50 cm water depth. Below 50cm of depth, the resulting pulse from the convolved surface, water column, and bottom reflection provide a means to measure depths between zero and 50 cm. The 2mr channel signals are susceptible to even very small amounts of suspended sediment in the water column. This characteristic seriously limits the useful measured depth from the 2mr channels. This sensor instrument incorporates a fourth 18mr wide detector channel to reduce susceptibility to suspended sediment, beam spreading due to irregular surface refraction and greatly extend the depth measuring capability of the instrument. The 18mr field-ofview (FOV) is configured to only detect laser light which is scattered outside the central 2mr FOV regions. The 2mr and the 18mr detectors

  3. Topographic map of the western region of Dao Vallis in Hellas Planitia, Mars; MTM 500k -40/082E OMKT

    USGS Publications Warehouse

    Rosiek, Mark R.; Redding, Bonnie L.; Galuszka, Donna M.

    2006-01-01

    This map, compiled photogrammetrically from Viking Orbiter stereo image pairs, is part of a series of topographic maps of areas of special scientific interest on Mars. Contours were derived from a digital terrain model (DTM) compiled on a digital photogrammetric workstation using Viking Orbiter stereo image pairs with orientation parameters derived from an analytic aerotriangulation. The image base for this map employs Viking Orbiter images from orbits 406 and 363. An orthophotomosaic was created on the digital photogrammetric workstation using the DTM compiled from stereo models.

  4. RapMap: a rapid, sensitive and accurate tool for mapping RNA-seq reads to transcriptomes

    PubMed Central

    Srivastava, Avi; Sarkar, Hirak; Gupta, Nitish; Patro, Rob

    2016-01-01

    Motivation: The alignment of sequencing reads to a transcriptome is a common and important step in many RNA-seq analysis tasks. When aligning RNA-seq reads directly to a transcriptome (as is common in the de novo setting or when a trusted reference annotation is available), care must be taken to report the potentially large number of multi-mapping locations per read. This can pose a substantial computational burden for existing aligners, and can considerably slow downstream analysis. Results: We introduce a novel concept, quasi-mapping, and an efficient algorithm implementing this approach for mapping sequencing reads to a transcriptome. By attempting only to report the potential loci of origin of a sequencing read, and not the base-to-base alignment by which it derives from the reference, RapMap—our tool implementing quasi-mapping—is capable of mapping sequencing reads to a target transcriptome substantially faster than existing alignment tools. The algorithm we use to implement quasi-mapping uses several efficient data structures and takes advantage of the special structure of shared sequence prevalent in transcriptomes to rapidly provide highly-accurate mapping information. We demonstrate how quasi-mapping can be successfully applied to the problems of transcript-level quantification from RNA-seq reads and the clustering of contigs from de novo assembled transcriptomes into biologically meaningful groups. Availability and implementation: RapMap is implemented in C ++11 and is available as open-source software, under GPL v3, at https://github.com/COMBINE-lab/RapMap. Contact: rob.patro@cs.stonybrook.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27307617

  5. Wakeful rest promotes the integration of spatial memories into accurate cognitive maps.

    PubMed

    Craig, Michael; Dewar, Michaela; Harris, Mathew A; Della Sala, Sergio; Wolbers, Thomas

    2016-02-01

    Flexible spatial navigation, e.g. the ability to take novel shortcuts, is contingent upon accurate mental representations of environments-cognitive maps. These cognitive maps critically depend on hippocampal place cells. In rodents, place cells replay recently travelled routes, especially during periods of behavioural inactivity (sleep/wakeful rest). This neural replay is hypothesised to promote not only the consolidation of specific experiences, but also their wider integration, e.g. into accurate cognitive maps. In humans, rest promotes the consolidation of specific experiences, but the effect of rest on the wider integration of memories remained unknown. In the present study, we examined the hypothesis that cognitive map formation is supported by rest-related integration of new spatial memories. We predicted that if wakeful rest supports cognitive map formation, then rest should enhance knowledge of overarching spatial relations that were never experienced directly during recent navigation. Forty young participants learned a route through a virtual environment before either resting wakefully or engaging in an unrelated perceptual task for 10 min. Participants in the wakeful rest condition performed more accurately in a delayed cognitive map test, requiring the pointing to landmarks from a range of locations. Importantly, the benefit of rest could not be explained by active rehearsal, but can be attributed to the promotion of consolidation-related activity. These findings (i) resonate with the demonstration of hippocampal replay in rodents, and (ii) provide the first evidence that wakeful rest can improve the integration of new spatial memories in humans, a function that has, hitherto, been associated with sleep. PMID:26235141

  6. Integrating Data from Several Remotely Sensed Platforms to Accurately Map Wetlands

    NASA Astrophysics Data System (ADS)

    Corcoran, Jennifer Marie

    Traditional wetland mapping methods are in need of modernization. They typically depend solely on few dates of optical imagery, cloud-free data acquisition, and therefore surface features of interest are often obstructed, inaccurately mapped, or not present during data acquisition. Despite the limitations of data acquisition during cloud-free daylight only, multi-temporal multi-spectral optical data are still highly valuable for mapping wetlands and classifying wetland type. However, radar sensors are unique in that they are insensitive to atmospheric and low light conditions, and thus can offer more consistent multi-temporal image acquisition. Unique characteristics about surface scattering mechanisms, such as saturated extent of wetlands, can be found by utilizing both the intensity and phase information from multiple polarizations and multiple wavelengths of radar data. In addition, information from lidar can reveal important details about the variability and structure of surface features, and the potentiality of water to collect in certain areas. The research presented in this dissertation will show important developments in wetland mapping by integrating several platforms of remotely sensed data, including: two sources of radar data including fully polarimetric RADARSAT-2 data (C-band) and dual-pol PALSAR data (L-band); two sources of optical data including Landsat TM imagery and aerial orthophotos, lidar point cloud data with intensity and derived topographic indices. Decision tree classification using the random forest model will be utilized to take advantage of the unique differences in these data. Assessments of outputs from random forest will be used to identify the most significant data sources for two levels of land cover classification: discriminating between water, wetland and upland areas, and sub-classifying wetland type. It is expected that results from this research will deliver a valuable, affordable, and practical wetland probability tool to aid

  7. Efficient and Accurate Construction of Genetic Linkage Maps from the Minimum Spanning Tree of a Graph

    PubMed Central

    Wu, Yonghui; Bhat, Prasanna R.; Close, Timothy J.; Lonardi, Stefano

    2008-01-01

    Genetic linkage maps are cornerstones of a wide spectrum of biotechnology applications, including map-assisted breeding, association genetics, and map-assisted gene cloning. During the past several years, the adoption of high-throughput genotyping technologies has been paralleled by a substantial increase in the density and diversity of genetic markers. New genetic mapping algorithms are needed in order to efficiently process these large datasets and accurately construct high-density genetic maps. In this paper, we introduce a novel algorithm to order markers on a genetic linkage map. Our method is based on a simple yet fundamental mathematical property that we prove under rather general assumptions. The validity of this property allows one to determine efficiently the correct order of markers by computing the minimum spanning tree of an associated graph. Our empirical studies obtained on genotyping data for three mapping populations of barley (Hordeum vulgare), as well as extensive simulations on synthetic data, show that our algorithm consistently outperforms the best available methods in the literature, particularly when the input data are noisy or incomplete. The software implementing our algorithm is available in the public domain as a web tool under the name MSTmap. PMID:18846212

  8. Glacier change over the last century, Caucasus Mountains, Georgia, observed from old topographical maps, Landsat and ASTER satellite imagery

    NASA Astrophysics Data System (ADS)

    Tielidze, Levan G.

    2016-03-01

    Changes in the area and number of glaciers in the Georgian Caucasus Mountains were examined over the last century, by comparing recent Landsat and ASTER images (2014) with older topographical maps (1911, 1960) along with middle and high mountain meteorological stations data. Total glacier area decreased by 8.1 ± 1.8 % (0.2 ± 0.04 % yr-1) or by 49.9 ± 10.6 km2 from 613.6 ± 9.8 km2 to 563.7 ± 11.3 km2 during 1911-1960, while the number of glaciers increased from 515 to 786. During 1960-2014, the total ice area decreased by 36.9 ± 2.2 % (0.7 ± 0.04 % yr-1) or by 207.9 ± 9.8 km2 from 563.7 ± 11.3 km2 to 355.8 ± 8.3 km2, while glacier numbers decreased from 786 to 637. In total, the area of Georgia glaciers reduced by 42.0 ± 2.0 % (0.4 ± 0.02 % yr-1) between 1911 and 2014. The eastern Caucasus section had the highest retreat rate of 67.3 ± 2.0 % (0.7 ± 0.02 % yr-1) over this period, while the central part of Georgian Caucasus had the lowest, 34.6 ± 1.8 % (0.3 ± 0.01 % yr-1), with the western Caucasus intermediate at 42.8 ± 2.7 % (0.4 ± 0.03 % yr-1).

  9. GIS integration of the 1:75,000 Romanian topographic map series from the World War I

    NASA Astrophysics Data System (ADS)

    Timár, G.; Mugnier, C. J.

    2009-04-01

    During the WWI, the Kingdom of Romania developed a 1:75,000 topographic map series, covering not only the actual territory of the country (the former Danube Principalities and Dobrogea) but also Bessarabia (now the Republic of Moldova), which was under Russian rule. The map sheets were issued between 1914 and 1917. The whole map consists of two zones; Columns A-F are the western zone, while Columns G-Q are belonging to the eastern one. To integrate the scanned map sheets to a geographic information system (GIS), the parameters of the map projection and the geodetic datum should be defined as well as the sheet labelling system. The sheets have no grid lines indicated; most of them have latitude and longitude lines but some of them have no coordinate descriptions. The sheets, however, can be rectified using their four corners as virtual control points, and using the following grid and datum parameters: Eastern zone: • Projection type: Bonne. • Projection center: latitude=46d 30m; longitude=27d 20m 13.35s (from Greenwich). • Base ellipsoid: Bessel 1841 • Datum parameters (from local to WGS84): dX=+875 m; dY=-119 m; dZ=+313 m. • Sheet size: 40*40 kilometers, projection center is the NW corner of the 779 (Column L; Row VII) sheet. Western zone: • Projection type: Bonne. • Projection center: latitude=45d; longitude=26d 6m 41.18s (from Greenwich); • Base ellipsoid: Bessel 1841 • Datum parameters (from local to WGS84): dX=+793 m; dY=+364 m; dZ=+173 m. • Sheet size: 0.6*0.4 grad (new degrees), except Column F, which is wider to east to fill the territory to the zone boundary. In Columns E and F geographic coordinates are indicated in new degrees, with the prime meridian of Bucharest. Apart from the system of columns and rows, each sheet has its own label of three or four digit. The last two digit correspond to the column number (69 for Column A going up to 84 for Column Q) while the first digit(s) refer directly to row number (1-15). During the

  10. Comparative lahar hazard mapping at Volcan Citlaltépetl, Mexico using SRTM, ASTER and DTED-1 digital topographic data

    NASA Astrophysics Data System (ADS)

    Hubbard, Bernard E.; Sheridan, Michael F.; Carrasco-Núñez, Gerardo; Díaz-Castellón, Rodolfo; Rodríguez, Sergio Raúl

    2007-02-01

    In this study, we evaluated and compared the utility of spaceborne SRTM and ASTER DEMs with baseline DTED-1 "bald-earth" topography for mapping lahar inundation hazards from volcan Citlaltépetl, Mexico, a volcano which has had a history of producing debris flows of various extents. In particular, we tested the utility of these topographic datasets for resolving ancient valley-filling deposits exposed around the flanks of the volcano, for determining their magnitude using paleohydrologic methods and for forecasting their inundation limits in the future. We also use the three datasets as inputs to a GIS stream inundation flow model, LAHARZ, and compare the results. In general all three datasets, with spatial resolution of 90 m or better, were capable of resolving debris flow and lahar deposits at least 3 × 10 6 m 3 in volume or larger. Canopy- and slope-related height errors in the ASTER and SRTM DEMs limit their utility for measuring valley-filling cross-sectional area and deriving flow magnitude for the smallest deposits using a cross-sectional area to volume scaling equation. Height errors in the ASTER and SRTM DEMs also causes problems in resolving stream valley hydrography which controls lahar flow paths and stream valley morphology which controls lahar filling capacity. However, both of the two spaceborne DEM datasets are better than DTED-1 at resolving fine details in stream hydrography and erosional morphologies of volcaniclastics preserved in the valleys around the more humid, eastern flanks of the volcanic range. The results of LAHARZ flow inundation modeling using all three DEMs as inputs are remarkably similar and co-validate one another. For example, at Citlaltépetl all lahar simulations show that the city of Orizaba is the most vulnerable to flows similar in magnitude to, or larger than, one that occurred in 1920. Many of the other cities and towns illustrated are built higher up on terrace deposits of older debris flows, and are safe from all but

  11. Glaciers change over the last century, Caucasus Mountains, Georgia, observed by the old topographical maps, Landsat and ASTER satellite imagery

    NASA Astrophysics Data System (ADS)

    Tielidze, L. G.

    2015-07-01

    The study of glaciers in the Caucasus began in the first quarter of the 18th century. The first data on glaciers can be found in the works of great Georgian scientist Vakhushti Bagrationi. After almost hundred years the foreign scientists began to describe the glaciers of Georgia. Information about the glaciers of Georgia can be found in the works of W. Abich (1865), D. Freshfield (1869), G. Radde (1873), N. Dinik (1884), I. Rashevskiy (1904), A. Reinhardt (1916, 1917) etc. The first statistical information about the glaciers of Georgia are found in the catalog of the Caucasus glaciers compiled by K. Podozerskiy in 1911 (Podozerkiy, 1911). Then, in 1960s the large-scale (1:25 000, 1:50 000) topographic maps were published, which were compiled in 1955-1960 on the basis of the space images. On the basis of the mentioned maps R. Gobejishvili gave quite detailed statistical information about the glaciers of Georgia (Gobejishvili, 1989). Then in 1975 the glaciological catalog of the former USSR was published (The Catalog of Glaciers of the USSR, Vol. 8-9, 1975), where the statistical information about the glaciers of Georgia was obtained on the basis of the space images of 1970-1975. Thus, complete statistical information on the glaciers of Georgia has not been published for about last 40 years. Data obtained by us by processing of the space images of Landsat and ASTER is the latest material, which is the best tool for identification of the change in the number and area of the glaciers of Georgia during the last one century. The article presents the percentage and quantitative changes in the number and area of the glaciers of Georgia in the years of 1911-1960-1975-2014, according to the individual river basins. The air temperature course of the Georgia's high mountain weather stations has been studied. The river basins have been revealed, where there are the highest indices of the reduction in area and number of the glaciers and the reasons have been explained.

  12. Mapping Quaternary Alluvial Fans in the Southwestern United States based on Multi-Parameter Surface Roughness of LiDAR Topographic Data

    NASA Astrophysics Data System (ADS)

    Regmi, N. R.; McDonald, E.; Bacon, S. N.

    2012-12-01

    Quaternary alluvial fans, common landforms in hyper- to semi-arid regions, have diverse surface morphology, desert varnish accumulation, clasts rubification, desert pavement formation, soil development, and soil stratigraphy. Their age and surface topographic expression vary greatly within a single fan between adjacent fans. Numerous studies have demonstrated that the surface expression and morphometry of alluvial fans can be used as an indicator of their relative age of deposition, but only recently has there been an effort to utilize high resolution topographic data to differentiate alluvial fans with automated and quantifiable routines We developed a quantitative model for mapping the relative age of alluvial fan surfaces based on a multi-parameter surface roughness computed from 1-meter resolution LiDAR topographic data. Roughness is defined as a function of scale of observation and the integration of slope, curvature (tangential), and aspect topographic parameters. Alluvial fan roughness values were computed across multiple observation scales (3m×3m to 150m×150m moving observation windows) based on the standard deviation (STD) of slope, curvature, and aspect. Plots of roughness value versus size of observation scale suggest that the STD of each of the three topographic parameters at 7m×7m observation window best identified the signature of surface roughness elements. Roughness maps derived from the slope, curvature, and aspect at this scale were integrated using fuzzy logic operators (fuzzy OR and fuzzy gamma). The integrated roughness map was then classified into five relative morpho-stratigraphic surface age categories (active wash to ~400 ka) and statistically compared with a similar five-fold surface age map of alluvial fans developed using traditional field surveys and aerial photo interpretation. The model correctly predicted the distribution and relative surface age of ~61% of the observed alluvial fan map. The results of the multi-parameter model

  13. Global, regional and local stratigraphy of dwarf planet (1) Ceres: results from geologic and topographic mapping using images of the Dawn camera

    NASA Astrophysics Data System (ADS)

    Wagner, Roland J.; Schmedemann, Nico; Stephan, Katrin; Jaumann, Ralf; Kneissl, Thomas; Neesemann, Adrian; Krohn, Katrin; Otto, Katharina; Preusker, Frank; Kersten, Elke; Roatsch, Thomas; Hiesinger, Harald; Williams, David A.; Yingst, Aileen; Crown, David A.; Mest, Scott C.; Raymond, Carol A.; Russell, Christopher T.

    2016-04-01

    Since its insertion into orbit around dwarf planet (1) Ceres, the camera aboard the Dawn spacecraft has been acquiring imaging data at increasing spatial resolutions from continuously lower orbit altitudes (Survey orbit, high-altitude and low-altitude mapping orbit (HAMO and LAMO, respectively)). In this paper we use global, regional and local mosaics of images from each of the various orbital phases for geologic mapping and crater counting. Geologic units are mapped according to morphology, topography, and superimposed crater frequency. Topographic information is taken from digital elevation models (DEMs). Stratigraphic positions of geologic and topographic units are obtained from their cumulative crater frequencies. Ceres' globally abundant cratered plains can be subdivided by their topographic position (high, middle, and low level) and by a generally higher or lower crater frequency (densely versus sparsely cratered plains). Large impact features and craters are mapped as separate units. Densely cratered plains were found to be the spatially most abundant units which occur at all three topographic levels, with cratering model ages ranging from ~3.7 - ~3.3 Ga. Sparsely cratered plains are on the order of ~3 Ga old. No correlation between model age and topographic level could be verified. The three large impact features Kerwan, Yalode and Urvara form an age sequence from older to younger, with cratering model ages of ~2.8 Ga, ~1.8 Ga, and 0.48 Ga respectively. Kerwan and Urvara can be used as stratigraphic markers to subdivide Ceres' stratigraphic column into the Urvaran (youngest), Kerwanan, and Pre-Kerwanan (oldest) system or period. Currently, the Dawn spacecraft is in the LAMO orbit, providing images with spatial resolutions of ~35 m/pxl. One of the first target areas to be examined in these data is the ~6 km high feature Ahuna Mons. Small craters on the summit region were measured and a model age of ~ 10 Ma was found, based on poor statistics, however. Also

  14. Modeling of geomagnetic field secular variations observed in the Balkan area for purposes of regional topographic mapping

    NASA Astrophysics Data System (ADS)

    Metodiev, Metodi; Trifonova, Petya; Buchvarov, Ivan

    2014-05-01

    question in geomagnetism whether induction by the slowly changing main field in conductive structures in the lithosphere is a measurable part of what is observed as secular variation at and above the Earth's surface. In our study we test different time-scale periods and different order polynomials to create the most appropriate prediction model and to estimate our results. We find that linear models which are used to determine the annual declination variation in cartography provide enough accurate information for the declination map's users.

  15. Wetland mapping and flood extent monitoring using optical and radar remotely sensed data and ancillary topographical data in the Zhalong National Natural Reserve, China

    NASA Astrophysics Data System (ADS)

    Na, Xiaodong; Zang, Shuying; Zhang, Yuhong; Liu, Lei

    2013-10-01

    Information regarding the spatial extent and inundation state in the internationally important Wetlands as designated by Ramsar Convention is important to a series of research questions including wetland ecosystem functioning and services, water management and habitat suitability assessment. This study develops an expedient digital mapping technique using optical remotely sensed imagery of the Landsat Thematic Mapper (TM), ENVISAT ASAR active radar C-band imagery, and topographical indices derived from topographic maps. All data inputs were resampled to a common 30 m resolution grid. An ensemble classifiers based on trees (random forest) procedure was employed to produce a final map of per-grid cell wetland probability map. This study also provides a general approach to delineate the extent of flooding builds upon documented relationships between fields measured inundation state and SAR data response on each vegetation types. The current study indicated that multi-source data (i.e. optical, radar and topography) are useful in the characterization of freshwater marshes and their inundation state. This analysis constitutes a necessary step towards improved herbaceous wetland monitoring and provides ecologists and managers with vital information that is related to ecology and hydrology in a wetland area.

  16. Pole Photogrammetry with AN Action Camera for Fast and Accurate Surface Mapping

    NASA Astrophysics Data System (ADS)

    Gonçalves, J. A.; Moutinho, O. F.; Rodrigues, A. C.

    2016-06-01

    High resolution and high accuracy terrain mapping can provide height change detection for studies of erosion, subsidence or land slip. A UAV flying at a low altitude above the ground, with a compact camera, acquires images with resolution appropriate for these change detections. However, there may be situations where different approaches may be needed, either because higher resolution is required or the operation of a drone is not possible. Pole photogrammetry, where a camera is mounted on a pole, pointing to the ground, is an alternative. This paper describes a very simple system of this kind, created for topographic change detection, based on an action camera. These cameras have high quality and very flexible image capture. Although radial distortion is normally high, it can be treated in an auto-calibration process. The system is composed by a light aluminium pole, 4 meters long, with a 12 megapixel GoPro camera. Average ground sampling distance at the image centre is 2.3 mm. The user moves along a path, taking successive photos, with a time lapse of 0.5 or 1 second, and adjusting the speed in order to have an appropriate overlap, with enough redundancy for 3D coordinate extraction. Marked ground control points are surveyed with GNSS for precise georeferencing of the DSM and orthoimage that are created by structure from motion processing software. An average vertical accuracy of 1 cm could be achieved, which is enough for many applications, for example for soil erosion. The GNSS survey in RTK mode with permanent stations is now very fast (5 seconds per point), which results, together with the image collection, in a very fast field work. If an improved accuracy is needed, since image resolution is 1/4 cm, it can be achieved using a total station for the control point survey, although the field work time increases.

  17. Using satellite vegetation and compound topographic indices to map highly erodible cropland buffers for cellulosic biofuel crop developments in eastern Nebraska, USA

    USGS Publications Warehouse

    Gu, Yingxin; Wylie, Bruce K.

    2015-01-01

    Cultivating annual row crops in high topographic relief waterway buffers has negative environmental effects and can be environmentally unsustainable. Growing perennial grasses such as switchgrass (Panicum virgatum L.) for biomass (e.g., cellulosic biofuel feedstocks) instead of annual row crops in these high relief waterway buffers can improve local environmental conditions (e.g., reduce soil erosion and improve water quality through lower use of fertilizers and pesticides) and ecosystem services (e.g., minimize drought and flood impacts on production; improve wildlife habitat, plant vigor, and nitrogen retention due to post-senescence harvest for cellulosic biofuels; and serve as carbon sinks). The main objectives of this study are to: (1) identify cropland areas with high topographic relief (high runoff potentials) and high switchgrass productivity potential in eastern Nebraska that may be suitable for growing switchgrass, and (2) estimate the total switchgrass production gain from the potential biofuel areas. Results indicate that about 140,000 hectares of waterway buffers in eastern Nebraska are suitable for switchgrass development and the total annual estimated switchgrass biomass production for these suitable areas is approximately 1.2 million metric tons. The resulting map delineates high topographic relief croplands and provides useful information to land managers and biofuel plant investors to make optimal land use decisions regarding biofuel crop development and ecosystem service optimization in eastern Nebraska.

  18. Application of new GPS aircraft control/display system to topographic mapping of the Greenland ice cap

    SciTech Connect

    Wright, C.W.; Swift, R.N.

    1996-10-01

    NASA has completed an accurate baseline map of the elevation of the Greenland ice sheet using a scanning airborne lidar in combination with differential kinematic Global Positioning System (GPS) techniques. The present plan is to reoccupy these survey lines which are spread over the major regions of the ice sheet beginning in 1997. The results are expected to provide a quantitative answer on how the ice sheet is responding to regional climatic changes. Navigation to within +-100 m of the desired track over lengths of up to 1,000 km are a requirement for the success of the program. To meet this navigational requirement, NASA developed the GPS Flight Management System (GFMS). GFMS is a PC based system that uses the real-time position update from a single GPS receiver located on the aircraft to calculate a cross-track error and generates aircraft steering commands which are converted into analog Instrument Landing System (OM) signals using an RF generator. TU GFMS also updates a cockpit display. 4 refs., 6 figs.

  19. Topographic Map of Quadrangles 3770 and 3870, Maymayk (211), Jamarj-I-Bala (212), Faydz-Abad (217), and Parkhaw (218) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  20. Topographic Map of Quadrangles 3168 and 3268, Yahya-Wona (703), Wersek (704), Khayr-Kot (521), and Urgon (522) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  1. Topographic Map of Quadrangles 3666 and 3766, Balkh (219), Mazar-I-Sharif (220), Qarqin (213), and Hazara Toghai (214) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  2. Topographic Map of Quadrangles 3764 and 3664, Jalajin (117), Kham-Ab (118), Char Shangho (123), and Sheberghan (124) Quadrangles, Afghanistan

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  3. Topographic Map of Quadrangle 3470 and the Northern Edge of 3370, Jalal-Abad (511), Chaghasaray (512), and Northernmost Jaji-Maydan (517) Quadrangles, Afg

    USGS Publications Warehouse

    Bohannon, Robert G.

    2006-01-01

    This map was produced from several larger digital datasets. Topography was derived from Shuttle Radar Topography Mission (SRTM) 85-meter digital data. Gaps in the original dataset were filled with data digitized from contours on 1:200,000-scale Soviet General Staff Sheets (1978-1997). Contours were generated by cubic convolution averaged over four pixels using TNTmips surface-modeling capabilities. Minor artifacts resulting from the auto-contouring technique are present. Streams were auto-generated from the SRTM data in TNTmips as flow paths. Flow paths were limited in number by their Horton value on a quadrangle-by-quadrangle basis. Peak elevations were averaged over an area measuring 85 m by 85 m (represented by one pixel), and they are slightly lower than the highest corresponding point on the ground. Cultural data were extracted from files downloaded from the Afghanistan Information Management Service (AIMS) Web site (http://www.aims.org.af). The AIMS files were originally derived from maps produced by the Afghanistan Geodesy and Cartography Head Office (AGCHO). Because cultural features were not derived from the SRTM base, they do not match it precisely. Province boundaries are not exactly located. This map is part of a series that includes a geologic map, a topographic map, a Landsat natural-color-image map, and a Landsat false-color-image map for the USGS/AGS (Afghan Geological Survey) quadrangles covering Afghanistan. The maps for any given quadrangle have the same open-file number but a different letter suffix, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively. The open-file report (OFR) numbers for each quadrangle range in sequence from 1092 - 1123. The present map series is to be followed by a second series, in which the geology is reinterpreted on the basis of analysis of remote-sensing data, limited fieldwork, and library research. The second series is to be produced by the USGS

  4. Forest Tree Species Distribution Mapping Using Landsat Satellite Imagery and Topographic Variables with the Maximum Entropy Method in Mongolia

    NASA Astrophysics Data System (ADS)

    Hao Chiang, Shou; Valdez, Miguel; Chen, Chi-Farn

    2016-06-01

    Forest is a very important ecosystem and natural resource for living things. Based on forest inventories, government is able to make decisions to converse, improve and manage forests in a sustainable way. Field work for forestry investigation is difficult and time consuming, because it needs intensive physical labor and the costs are high, especially surveying in remote mountainous regions. A reliable forest inventory can give us a more accurate and timely information to develop new and efficient approaches of forest management. The remote sensing technology has been recently used for forest investigation at a large scale. To produce an informative forest inventory, forest attributes, including tree species are unavoidably required to be considered. In this study the aim is to classify forest tree species in Erdenebulgan County, Huwsgul province in Mongolia, using Maximum Entropy method. The study area is covered by a dense forest which is almost 70% of total territorial extension of Erdenebulgan County and is located in a high mountain region in northern Mongolia. For this study, Landsat satellite imagery and a Digital Elevation Model (DEM) were acquired to perform tree species mapping. The forest tree species inventory map was collected from the Forest Division of the Mongolian Ministry of Nature and Environment as training data and also used as ground truth to perform the accuracy assessment of the tree species classification. Landsat images and DEM were processed for maximum entropy modeling, and this study applied the model with two experiments. The first one is to use Landsat surface reflectance for tree species classification; and the second experiment incorporates terrain variables in addition to the Landsat surface reflectance to perform the tree species classification. All experimental results were compared with the tree species inventory to assess the classification accuracy. Results show that the second one which uses Landsat surface reflectance coupled

  5. Refining global mapping of foliage clumping index and leaf area index with multi-angular POLDER 3 measurements: validation and topographic compensation

    NASA Astrophysics Data System (ADS)

    Pisek, J.; Chen, J. M.; Lacaze, R.; Alikas, K.

    2009-05-01

    The clumping index quantifies the level of foliage grouping within distinct canopy structures, such as tree crowns, shrubs, and row crops, relative to a random distribution. In addition to the effective leaf area index retrieved from mono-angle remote sensing, vegetation foliage clumping is a critical new source of information for advanced modelling of radiation interaction with vegetation and energy and mass (water and carbon) exchanges between the surface and the atmosphere. Clumping index can be derived from the angular signature of the reflectance at the hotspot, when the sun and view angles coincide, and at the dark spot, where the reflectance is at its minimum. The relationship was previously used to derive a first ever global clumping index map at 6 km by 6 km resolution using multi-angular POLDER 1 satellite data. The original POLDER 1 global clumping map had several limitations that are removed in this study. The addressed drawbacks are a limited spatial coverage, topographic effects, and a lack of direct validation with field measurements. First, global coverage is expanded, particularly over North America and North Asia, by integrating new, complete year-round observations from POLDER 3. Next, we show that terrain-induced shadows can enhance BRDF variation and bias negatively the clumping index (i.e. more clumped vegetation than in reality) in hilly regions. Using a global higher resolution DEM, a topographic compensation function is devised to correct for the terrain effect. The clumping index reductions can reach up to 30%, depending on terrain complexity and land cover type. The new global index map is then validated with an assembled set of over 50 different site field measurements of clumping index, covering four continents and diverse biomes. The results show that the POLDER-derived clumping index values integrate the effect of vegetation clumping both at the scales larger and smaller than a shoot - values that can be obtained only by separate

  6. Mapping of Inner and Outer Celestial Bodies Using New Global and Local Topographic Data Derived from Photogrammetric Image Processing

    NASA Astrophysics Data System (ADS)

    Karachevtseva, I. P.; Kokhanov, A. A.; Rodionova, J. F.; Zharkova, A. Yu.; Lazareva, M. S.

    2016-06-01

    New estimation of fundamental geodetic parameters and global and local topography of planets and satellites provide basic coordinate systems for mapping as well as opportunities for studies of processes on their surfaces. The main targets of our study are Europa, Ganymede, Calisto and Io (satellites of Jupiter), Enceladus (a satellite of Saturn), terrestrial planetary bodies, including Mercury, the Moon and Phobos, one of the Martian satellites. In particular, based on new global shape models derived from three-dimensional control point networks and processing of high-resolution stereo images, we have carried out studies of topography and morphology. As a visual representation of the results, various planetary maps with different scale and thematic direction were created. For example, for Phobos we have produced a new atlas with 43 maps, as well as various wall maps (different from the maps in the atlas by their format and design): basemap, topography and geomorphological maps. In addition, we compiled geomorphologic maps of Ganymede on local level, and a global hypsometric Enceladus map. Mercury's topography was represented as a hypsometric globe for the first time. Mapping of the Moon was carried out using new images with super resolution (0.5-1 m/pixel) for activity regions of the first Soviet planetary rovers (Lunokhod-1 and -2). New results of planetary mapping have been demonstrated to the scientific community at planetary map exhibitions (Planetary Maps Exhibitions, 2015), organized by MExLab team in frame of the International Map Year, which is celebrated in 2015-2016. Cartographic products have multipurpose applications: for example, the Mercury globe is popular for teaching and public outreach, the maps like those for the Moon and Phobos provide cartographic support for Solar system exploration.

  7. Ice Shell Thickness and Endogenic Processes on Europa from Mapping and Topographic Analyses of Pits, Uplifts and Small Chaos Features (Invited)

    NASA Astrophysics Data System (ADS)

    Singer, K. N.; McKinnon, W. B.; Schenk, P.

    2013-12-01

    Constraining the thickness of the ice shell on Europa and the geological processes occurring in it are keys to understanding this icy world and its potential habitability. We focus on circular-to-subcircular features generally agreed to have been created by endogenic processes in Europa's ice shell or ocean: pits, uplifts, and subcircular chaos. Pits and uplifts are defined by their negative or positive topographic expression, respectively. Pits and uplifts generally retain pre-existing surface structures such as ridges, while chaos specifically refers to areas where the surface is broken up, in some cases to the point of destroying all original surface topography. We have mapped all features plausibly created by upwellings or other endogenic processes in the size range of 1 to 50 km in diameter, and incorporated previously unavailable topographic data as an aid to mapping and characterization of features. Topography was derived from albedo-controlled photoclinometry and crosschecked with stereo data where possible. Mapping was carried out over the medium-resolution Galileo regional maps (RegMaps) covering approximately 9% of Europa's surface, as well as over available high-resolution regions. While limited in extent, the latter are extremely valuable for detecting smaller features and for overall geomorphological analysis. Results of this new mapping show decreasing numbers of small features, and a peak in the size distribution for all features at approximately 5-6 km in diameter. No pits smaller than 3.3 km in diameter were found in high resolution imagery. Topography was used to find the depths and heights of pits and uplifts in the mapped regions. A general trend of increasing pit depth with increasing pit size was found, a correlation more easily understood in the context of a diapiric hypothesis for feature formation (as opposed to purely non-diapiric, melt-through models). Based on isostasy, maximum pit depths of ~0.3-to-0.48 km imply a minimum shell

  8. Using ground-based geophysics to rapidly and accurately map sub-surface acidity

    NASA Astrophysics Data System (ADS)

    Wong, Vanessa; Triantafilis, John; Johnston, Scott; Nhan, Terence; Page, Donald; Wege, Richard; Hirst, Phillip; Slavich, Peter

    2013-04-01

    sulfuric and sulfidic layers (oxidised and reduced ASS), acidic shallow groundwater, and features of the infilled palaeovalley (Triantafilis et al. 2012). Accurate soil maps with high spatial resolution are required to develop appropriate management strategies for ASS and other soil types associated with low-lying coastal floodplains. The classes identified in this study form sensible soil management zones across the study area related to defined geomorphic units. EM data can then be used to build below-ground 3D models to inform practical targeted management strategies on coastal floodplains to improve land and water quality outcomes. References Triantafilis J, Wong V, Santos FAM, Page D, Wege R (2012) Modeling the electrical conductivity of hydrogeological strata using joint-inversion of loop-loop electromagnetic data. Geophysics 77(4): WB99-WB107

  9. History of the topographic branch (division)

    USGS Publications Warehouse

    Evans, Richard T.; Frye, Helen M.

    2009-01-01

    the Pacific Coast. These expeditions were sent out by the War Department and were in charge of Army officers. It is interesting to note that such generals as George G. Meade, J.C. Fremont, Joseph E. Johnston, W.F. Smith, John Pope, A.W. Whipple, J.G. Parke, G.K. Warren, and H.L. Abbott, all officers of the Corps of Topographic Engineers, had charge of expeditions and were among our earliest map makers. Unfortunately, the data obtained by these editions were not of sufficient accuracy to serve as a basis for topographic maps of value other than in illustrating their voluminous reports. During this early period, numerous surveys were undertaken within the original Thirteen States, by the Federal government and by the States. The most important were those carried on by the U.S. Coast and Geodetic Survey, which made an accurate survey of the Atlantic Coastline and established a triangulation system that was of so high a standard as to constitute the first and only accurate data for topographic mapping obtained before the Civil War. The Coast and Geodetic Survey, while charting the coast and rivers, also mapped a strip of country extending a few miles inland, the relief being shown by means of hachures, together with contour lines, until 1846 when the first government topographic map on which the relief was shown by contours alone was made, covering an area in the vicinity of Boston Harbor. In 1835, however, the Geological and Topographical Survey of Maryland had issued a map on which the relief was shown by contours, and this is believed to be the first contoured map issued in this country. The outbreak of the Civil War stopped all mapping activities other than those needed by the U.S. Army. During the war, topographic surveys were carried on throughout the war zone under the supervision of the Corps of Engineers, the topographers being civilian employees. After the war, the country west of the Mississippi again became the center of the mapping activities

  10. The 2006 Danube flood inundation patterns and the 1864 topographic map of South Romania: How the present hydrological processes are determined by the original landscape?

    NASA Astrophysics Data System (ADS)

    Timár, Gábor; Bartos, Zsombor; Imecs, Zoltán; Magyari-Sáska, Zsolt; Crăciunescu, Vasile; Flueraru, Cristian

    2014-05-01

    The satellite-based inundation maps of the 2006 Danube floods in Romania were fit geometrically to the 1864 topographic map sheets covering the Romanian regions of Oltenia and Muntenia. The old maps were systematically geo-referenced using the data of the original geodetic control and cartographic details; their Cassini-Soldner projection was properly parametrized and completed by the data of the original geodetic datum. The sheets were geo-referred using ground control points only at their four corners, knowing their coordinates in their own projection. The coupled satellite data was provided by the Landsat and MODIS data, all transformed to the modern grid system of Romania. The inundation patterns in the Danube embayments of Ghidici, Bechet and Calaraşi were analyzed on the historical map content layer. The comparison was made in two aspects: (1) how the low floodplain, inundated by the recent big flood was marked in the historical sheets, reflecting its old, almost original environmental setting, and (2) how the historical settlement outlines were changed during the passed 150 years, mostly because of the flood events. The comparison provide interesting examples about the inundation 'islands' during the flood and their original state as well as 'settlement moving' from the low and middle-level floodplain to the flood-free terraces. This work was supported by a grant of the Romanian National Authority for Scientific Research, CNCS - UEFISCDI, project number PN-II-RU-TE-2011-3-0125 and the Project NATO SfP 978016.

  11. Topographical atlas sheets

    USGS Publications Warehouse

    Wheeler, George Montague

    1877-01-01

    The following topographical atlas maps, published during the year, accompany the copies of Appendix N.N. of the Annual Report of the Chief of Engineers for 1877, beinig Annual Report of Lieut. Geo. M. Wheeler, Corps of Engineers, in charge of U. S. Geographical Surveys, are in continuation of the series ninety-five in number, on a scale of 1 inch to 8 miles, embracing the territory of the United States lying west of the 100th meridian.

  12. Happy and less inhibited? Effects of positive mood on inhibitory control during an antisaccade task revealed using topographic evoked potential mapping.

    PubMed

    Vanlessen, Naomi; De Raedt, Rudi; Mueller, Sven C; Rossi, Valentina; Pourtois, Gilles

    2015-09-01

    Affective states might influence inhibitory control, a cognitive process fundamental for goal adaptive behavior. Here, we recorded high-density EEG while participants performed an antisaccade task, after the induction of a happy (n=20) or neutral (n=20) mood, to compare the same inhibition-related processes across these two affective contexts. Topographical evoked potential mapping methods were used to characterize changes in the electric field depending on mood and saccade type (pro vs. anti) concurrently. Results showed that prior to target onset, the CNV component was enhanced for anti- compared to prosaccades, selectively in the neutral mood group. Following target onset, the topography of the N2 was more strongly expressed in the happy mood group, and was also altered by saccade type. The subsequent P3 components were not modulated by mood. We discuss these new findings in light of recent neurobiological and neuropsychological models that posit that positive affect dynamically changes cognitive control. PMID:26196900

  13. Using infrared spectroscopy and satellite data to accurately monitor remote volcanoes and map their eruptive products

    NASA Astrophysics Data System (ADS)

    Ramsey, M. S.

    2011-12-01

    The ability to detect the onset of new activity at a remote volcano commonly relies on high temporal resolution thermal infrared (TIR) satellite-based observations. These observations from sensors such as AVHRR and MODIS are being used in innovative ways to produce trends of activity, which are critical for hazard response planning and scientific modeling. Such data are excellent for detection of new thermal features, volcanic plumes, and tracking changes over the hour time scale, for example. For some remote volcanoes, the lack of ground-based monitoring typically means that these sensors provide the first and only confirmation of renewed activity. However, what is lacking is the context of the higher spatial scale, which provides the volcanologist with meter-scale information on specific temperatures and changes in the composition and texture of the eruptive products. For the past eleven years, the joint US-Japanese ASTER instrument has been acquiring image-based data of volcanic eruptions around the world, including in the remote northern Pacific region. There have been more ASTER observations of Kamchatka volcanoes than any other location on the globe due mainly to an operational program put into place in 2004. Automated hot spot alarms from AVHRR data trigger ASTER acquisitions using the instrument's "rapid response" mode. Specifically for Kamchatka, this program has resulted in more than 700 additional ASTER images of the most thermally-active volcanoes (e.g., Shiveluch, Kliuchevskoi, Karymsky, Bezymianny). The scientific results from this program at these volcanoes will be highlighted. These results were strengthened by several field seasons used to map new products, collect samples for laboratory-based spectroscopy, and acquire TIR camera data. The fusion of ground, laboratory and space-based spectroscopy provided the most accurate interpretation of the eruptions and laid the ground work for future VSWIR/TIR sensors such as HyspIRI, which are a critically

  14. The use of historical topographic maps in the study of forest-cover changes in Southern Romania

    NASA Astrophysics Data System (ADS)

    Imecs, Zoltán; Bartos-Elekes, Zsombor; Timár, Gábor; Magyari-Sáska, Zsolt

    2014-05-01

    In the post-communist period the term "deforestation" becomes well known in Romania. By the middle of 19th-century more than 27% of the country was covered by forests, but since then certain changes took place in this respect. The study of the phenomena can be done by the help of maps. In this regard it is very important to have old maps which can emphasize the situation from the past. As the map of Southern Romania, made about Walachia in 1864, called Charta României Meridionale is now georeferenced and accessible on the web, it can be used as a basis for such studies. Researchers are now able to make quantitative studies. In our poster we made a study of two different regions from Southern Romania: one from a mountain region and one from a plain region. Both are in the basin of Argeş river, tributary of Danube. The mountain region lies in the upper basin of Argeş river which is now occupied Vidraru artificial lake. The plain region lies on wetland and today is a natural reserve. The study regions have almost the same size (about 400 km2). In order to follow the evolution in time of the forest cover we used four data sources which covers a period of more than 150 years: Charta României Meridionale (the survey was made between 1855 and 1859); Lambert-Cholesky maps (the survey was made at the end of the 19th century); Gauss-Krüger maps (from the 1960s) and orthophotographs made in 2005. All these materials are georeferenced. With the help of GIS software we digitized the areas covered by forests in both regions. The areas were determined and compared. Using GIS techniques we can overlap the areas covered by forests, the illustrations were made this way. As a conclusion we can say that the plain region suffered important changes as the natural landscape turns into an agricultural-human landscape in the first part of the 20th century. We can say that the actual forest is preserved only because now it is a protected area. In the mountain region the territory was

  15. Comparative lahar hazard mapping at Volcan Citlaltépetl, Mexico using SRTM, ASTER and DTED-1 digital topographic data

    USGS Publications Warehouse

    Hubbard, Bernard E.; Sheridan, Michael F.; Carrasco-Nunez, Gerardo; Diaz-Castellon, Rodolfo; Rodriguez, Sergio R.

    2007-01-01

    Finally, ASTERs 60 km swath width and 8% duty cycle presents a challenge for mapping lahar inundation hazards at E–W oriented stream valleys in low-latitude areas with persistent cloud cover. However, its continued operations enhances its utility as a means for updating the continuous but one-time coverage of SRTM, and for filling voids in the SRTM dataset such as those that occur along steep-sided valleys prone to hazards from future lahars.

  16. EphA3 Expressed in the Chicken Tectum Stimulates Nasal Retinal Ganglion Cell Axon Growth and Is Required for Retinotectal Topographic Map Formation

    PubMed Central

    Rapacioli, Melina; Salierno, Marcelo; Etchenique, Roberto; Flores, Vladimir; Sanchez, Viviana; Carri, Néstor Gabriel; Scicolone, Gabriel

    2012-01-01

    Background Retinotopic projection onto the tectum/colliculus constitutes the most studied model of topographic mapping and Eph receptors and their ligands, the ephrins, are the best characterized molecular system involved in this process. Ephrin-As, expressed in an increasing rostro-caudal gradient in the tectum/colliculus, repel temporal retinal ganglion cell (RGC) axons from the caudal tectum and inhibit their branching posterior to their termination zones. However, there are conflicting data regarding the nature of the second force that guides nasal axons to invade and branch only in the caudal tectum/colliculus. The predominant model postulates that this second force is produced by a decreasing rostro-caudal gradient of EphA7 which repels nasal optic fibers and prevents their branching in the rostral tectum/colliculus. However, as optic fibers invade the tectum/colliculus growing throughout this gradient, this model cannot explain how the axons grow throughout this repellent molecule. Methodology/Principal Findings By using chicken retinal cultures we showed that EphA3 ectodomain stimulates nasal RGC axon growth in a concentration dependent way. Moreover, we showed that nasal axons choose growing on EphA3-expressing cells and that EphA3 diminishes the density of interstitial filopodia in nasal RGC axons. Accordingly, in vivo EphA3 ectodomain misexpression directs nasal optic fibers toward the caudal tectum preventing their branching in the rostral tectum. Conclusions We demonstrated in vitro and in vivo that EphA3 ectodomain (which is expressed in a decreasing rostro-caudal gradient in the tectum) is necessary for topographic mapping by stimulating the nasal axon growth toward the caudal tectum and inhibiting their branching in the rostral tectum. Furthermore, the ability of EphA3 of stimulating axon growth allows understanding how optic fibers invade the tectum growing throughout this molecular gradient. Therefore, opposing tectal gradients of repellent ephrin

  17. A Framework for Accurate Geospatial Modeling of Recharge and Discharge Maps using Image Ranking and Machine Learning

    NASA Astrophysics Data System (ADS)

    Yahja, A.; Kim, C.; Lin, Y.; Bajcsy, P.

    2008-12-01

    This paper addresses the problem of accurate estimation of geospatial models from a set of groundwater recharge & discharge (R&D) maps and from auxiliary remote sensing and terrestrial raster measurements. The motivation for our work is driven by the cost of field measurements, and by the limitations of currently available physics-based modeling techniques that do not include all relevant variables and allow accurate predictions only at coarse spatial scales. The goal is to improve our understanding of the underlying physical phenomena and increase the accuracy of geospatial models--with a combination of remote sensing, field measurements and physics-based modeling. Our approach is to process a set of R&D maps generated from interpolated sparse field measurements using existing physics-based models, and identify the R&D map that would be the most suitable for extracting a set of rules between the auxiliary variables of interest and the R&D map labels. We implemented this approach by ranking R&D maps using information entropy and mutual information criteria, and then by deriving a set of rules using a machine learning technique, such as the decision tree method. The novelty of our work is in developing a general framework for building geospatial models with the ultimate goal of minimizing cost and maximizing model accuracy. The framework is demonstrated for groundwater R&D rate models but could be applied to other similar studies, for instance, to understanding hypoxia based on physics-based models and remotely sensed variables. Furthermore, our key contribution is in designing a ranking method for R&D maps that allows us to analyze multiple plausible R&D maps with a different number of zones which was not possible in our earlier prototype of the framework called Spatial Pattern to Learn. We will present experimental results using examples R&D and other maps from an area in Wisconsin.

  18. Topographic maps of human motor cortex in normal and pathological conditions: mirror movements, amputations and spinal cord injuries.

    PubMed

    Cohen, L G; Bandinelli, S; Topka, H R; Fuhr, P; Roth, B J; Hallett, M

    1991-01-01

    We studied motor evoked potentials to transcranial magnetic stimulation in patients with unilateral upper limb amputations, complete T10-T12 spinal cord transection, and congenital mirror movements and in controls. Different muscles in the trunk and upper and lower extremities were evaluated at rest. In controls, muscles could be activated with stimulation of regions several centimeters wide. These areas overlapped extensively when muscles studied were from the same limb and shifted positions abruptly when muscles were from different limbs. Distal muscles were easier to activate than proximal muscles and normally evidenced exclusively a contralateral representation. Congenital defects in motor control in patients with mirror movements resulted in marked derangement of the map of outputs of distal hand muscles with enlarged and ipsilateral representations. Peripheral lesions, either acquired (amputations) or congenital (congenital absence of a limb), resulted in plastic reorganization of motor outputs targeting muscles immediately proximal to the stump. Central nervous system lesions (i.e., spinal cord injury producing paraplegia) also resulted in enlargement of the map of outputs targeting muscles proximal to the lesion. These results indicate that magnetic stimulation is a useful non-invasive tool for exploring plastic changes in human motor pathways following different types of injury. PMID:1773774

  19. Topographic pharmaco-EEG mapping of the effects of the South American psychoactive beverage ayahuasca in healthy volunteers

    PubMed Central

    Riba, Jordi; Anderer, Peter; Morte, Adelaida; Urbano, Gloria; Jané, Francesc; Saletu, Bernd; Barbanoj, Manel J

    2002-01-01

    Aims Ayahuasca is a traditional South American psychoactive beverage used in Amazonian shamanism, and in the religious ceremonies of Brazilian-based syncretic religious groups with followers in the US and several European countries. This tea contains measurable amounts of the psychotropic indole N,N-dimethyltryptamine (DMT), and β-carboline alkaloids with MAO-inhibiting properties. In a previous report we described a profile of stimulant and psychedelic effects for ayahuasca as measured by subjective report self-assessment instruments. In the present study the cerebral bioavailability and time-course of effects of ayahuasca were assessed in humans by means of topographic quantitative-electroencephalography (q-EEG), a noninvasive method measuring drug-induced variations in brain electrical activity. Methods Two doses (one low and one high) of encapsulated freeze-dried ayahuasca, equivalent to 0.6 and 0.85 mg DMT kg−1 body weight, were administered to 18 healthy volunteers with previous experience in psychedelic drug use in a double-blind crossover placebo-controlled clinical trial. Nineteen-lead recordings were undertaken from baseline to 8 h after administration. Subjective effects were measured by means of the Hallucinogen Rating Scale (HRS). Results Ayahuasca induced a pattern of psychoactive effects which resulted in significant dose-dependent increases in all subscales of the HRS, and in significant and dose-dependent modifications of brain electrical activity. Absolute power decreased in all frequency bands, most prominently in the theta band. Mean absolute power decreases (95% CI) at a representative lead (P3) 90 min after the high dose were −20.20±15.23 µV2 and −2.70±2.21 µV2 for total power and theta power, respectively. Relative power decreased in the delta (−1.20±1.31% after 120 min at P3) and theta (−3.30±2.59% after 120 min at P3) bands, and increased in the beta band, most prominently in the faster beta-3 (1.00±0.88% after 90 min at P

  20. Topographic projection from the optic tectum to the auditory space map in the inferior colliculus of the barn owl.

    PubMed

    Hyde, P S; Knudsen, E I

    2000-05-29

    In the barn owl (Tyto alba), the external nucleus of the inferior colliculus (ICX) contains a map of auditory space that is calibrated by visual experience. The source of the visually based instructive signal to the ICX is unknown. Injections of biotinylated dextran amine and Fluoro-Gold in the ICX retrogradely labelled neurons in layers 8-15 of the ipsilateral optic tectum (OT) that could carry this instructive signal. This projection was point-to-point and in register with the feed-forward, auditory projection from the ICX to the OT. Most labelled neurons were in layers 10-11, and most were bipolar. Tripolar, multipolar, and unipolar neurons were also observed. Multipolar neurons had dendrites that were oriented parallel to the tectal laminae. In contrast, most labelled bipolar and tripolar neurons had dendrites oriented perpendicular to the tectal laminae, extending superficially into the retino-recipient laminae and deep into the auditory recipient laminae. Therefore, these neurons were positioned to receive both visual and auditory information from particular locations in space. Biocytin injected into the superficial layers of the OT labelled bouton-laden axons in the ICX. These axons were generally finer than, but had similar bouton densities as, feed-forward auditory fibers in the ICX, labelled by injections of biocytin into the central nucleus of the inferior colliculus (ICC). These data demonstrate a point-to-point projection from the OT to the ICX that could provide a spatial template for calibrating the auditory space map in the ICX. PMID:10813778

  1. Topographical mapping of α- and β-keratins on developing chicken skin integuments: Functional interaction and evolutionary perspectives

    PubMed Central

    Wu, Ping; Ng, Chen Siang; Yan, Jie; Lai, Yung-Chih; Chen, Chih-Kuan; Lai, Yu-Ting; Wu, Siao-Man; Chen, Jiun-Jie; Luo, Weiqi; Widelitz, Randall B.; Li, Wen-Hsiung; Chuong, Cheng-Ming

    2015-01-01

    Avian integumentary organs include feathers, scales, claws, and beaks. They cover the body surface and play various functions to help adapt birds to diverse environments. These keratinized structures are mainly composed of corneous materials made of α-keratins, which exist in all vertebrates, and β-keratins, which only exist in birds and reptiles. Here, members of the keratin gene families were used to study how gene family evolution contributes to novelty and adaptation, focusing on tissue morphogenesis. Using chicken as a model, we applied RNA-seq and in situ hybridization to map α- and β-keratin genes in various skin appendages at embryonic developmental stages. The data demonstrate that temporal and spatial α- and β-keratin expression is involved in establishing the diversity of skin appendage phenotypes. Embryonic feathers express a higher proportion of β-keratin genes than other skin regions. In feather filament morphogenesis, β-keratins show intricate complexity in diverse substructures of feather branches. To explore functional interactions, we used a retrovirus transgenic system to ectopically express mutant α- or antisense β-keratin forms. α- and β-keratins show mutual dependence and mutations in either keratin type results in disrupted keratin networks and failure to form proper feather branches. Our data suggest that combinations of α- and β-keratin genes contribute to the morphological and structural diversity of different avian skin appendages, with feather-β-keratins conferring more possible composites in building intrafeather architecture complexity, setting up a platform of morphological evolution of functional forms in feathers. PMID:26598683

  2. Topographical mapping of α- and β-keratins on developing chicken skin integuments: Functional interaction and evolutionary perspectives.

    PubMed

    Wu, Ping; Ng, Chen Siang; Yan, Jie; Lai, Yung-Chih; Chen, Chih-Kuan; Lai, Yu-Ting; Wu, Siao-Man; Chen, Jiun-Jie; Luo, Weiqi; Widelitz, Randall B; Li, Wen-Hsiung; Chuong, Cheng-Ming

    2015-12-01

    Avian integumentary organs include feathers, scales, claws, and beaks. They cover the body surface and play various functions to help adapt birds to diverse environments. These keratinized structures are mainly composed of corneous materials made of α-keratins, which exist in all vertebrates, and β-keratins, which only exist in birds and reptiles. Here, members of the keratin gene families were used to study how gene family evolution contributes to novelty and adaptation, focusing on tissue morphogenesis. Using chicken as a model, we applied RNA-seq and in situ hybridization to map α- and β-keratin genes in various skin appendages at embryonic developmental stages. The data demonstrate that temporal and spatial α- and β-keratin expression is involved in establishing the diversity of skin appendage phenotypes. Embryonic feathers express a higher proportion of β-keratin genes than other skin regions. In feather filament morphogenesis, β-keratins show intricate complexity in diverse substructures of feather branches. To explore functional interactions, we used a retrovirus transgenic system to ectopically express mutant α- or antisense β-keratin forms. α- and β-keratins show mutual dependence and mutations in either keratin type results in disrupted keratin networks and failure to form proper feather branches. Our data suggest that combinations of α- and β-keratin genes contribute to the morphological and structural diversity of different avian skin appendages, with feather-β-keratins conferring more possible composites in building intrafeather architecture complexity, setting up a platform of morphological evolution of functional forms in feathers. PMID:26598683

  3. Molecular, topographic, and functional organization of the cerebellar nuclei: analysis by three-dimensional mapping of the olivonuclear projection and aldolase C labeling.

    PubMed

    Sugihara, Izumi; Shinoda, Yoshikazu

    2007-09-01

    The olivocerebellar climbing fiber projection pattern is closely correlated with the pattern of aldolase C expression in cerebellar Purkinje cells. Based on this expression pattern, the olivocerebellar projection can be classified into five "groups" of functional compartments. Each group originates from a subarea within the inferior olive that projects to multiple cortical stripes of Purkinje cells, all of which are either aldolase C positive or aldolase C negative. However, no equivalent compartmental organization has been demonstrated in the cerebellar nuclei (CN). Thus, in the CN of the rat, we systematically mapped the location of olivonuclear projections belonging to the five groups and determined their relationship to the expression of aldolase C in Purkinje cell axonal terminals. The CN were divided into caudoventral aldolase C-positive and rostrodorsal aldolase C-negative parts. The olivonuclear terminations from the five groups projected topographically to five separate compartments within the CN that partly crossed the traditional boundaries that define the fastigial, interposed, and dentate nuclei. Each compartment had mostly uniform cytoarchitecture and the same aldolase C expression (either positive or negative) that was found in the corresponding olivocortical projection. These results suggest a new view of the organization of the CN whereby the pattern of olivonuclear terminations links portions of different CN together. We propose that each compartment in the CN, along with its corresponding olivary subarea and cortical stripes, may be related to a different aspect of motor control. PMID:17804630

  4. Mapping the topographic epitope landscape on the urokinase plasminogen activator receptor (uPAR) by surface plasmon resonance and X-ray crystallography.

    PubMed

    Zhao, Baoyu; Gandhi, Sonu; Yuan, Cai; Luo, Zhipu; Li, Rui; Gårdsvoll, Henrik; de Lorenzi, Valentina; Sidenius, Nicolai; Huang, Mingdong; Ploug, Michael

    2015-12-01

    The urokinase-type plasminogen activator receptor (uPAR or CD87) is a glycolipid-anchored membrane protein often expressed in the microenvironment of invasive solid cancers and high levels are generally associated with poor patient prognosis (Kriegbaum et al., 2011 [1]). uPAR is organized as a dynamic modular protein structure composed of three homologous Ly6/uPAR domains (LU).This internally flexible protein structure of uPAR enables an allosteric regulation of the interactions with its two principal ligands: the serine protease urokinase-type plasminogen activator (uPA) and the provisional matrix protein vitronectin (Vn) (Mertens et al., 2012; Gårdsvoll et al., 2011; Madsen et al., 2007 [2-4]). The data presented here relates to the non-covalent trapping of one of these biologically relevant uPAR-conformations by a novel class of monoclonal antibodies (Zhao et al., 2015 [5]) and to the general mapping of the topographic epitope landscape on uPAR. The methods required to achieve these data include: (1) recombinant expression and purification of a uPAR-hybrid protein trapped in the desired conformation [patent; WO 2013/020898 A12013]; (2) developing monoclonal antibodies with unique specificities using this protein as antigen; (3) mapping the functional epitope on uPAR for these mAbs by surface plasmon resonance with a complete library of purified single-site uPAR mutants (Zhao et al., 2015; Gårdsvoll et al., 2006 [5,6]); and finally (4) solving the three-dimensional structures for one of these mAbs by X-ray crystallography alone and in complex with uPAR [deposited in the PDB database as 4QTH and 4QTI, respectively]. PMID:26504891

  5. Brain MAPS: an automated, accurate and robust brain extraction technique using a template library

    PubMed Central

    Leung, Kelvin K.; Barnes, Josephine; Modat, Marc; Ridgway, Gerard R.; Bartlett, Jonathan W.; Fox, Nick C.; Ourselin, Sébastien

    2011-01-01

    Whole brain extraction is an important pre-processing step in neuro-image analysis. Manual or semi-automated brain delineations are labour-intensive and thus not desirable in large studies, meaning that automated techniques are preferable. The accuracy and robustness of automated methods are crucial because human expertise may be required to correct any sub-optimal results, which can be very time consuming. We compared the accuracy of four automated brain extraction methods: Brain Extraction Tool (BET), Brain Surface Extractor (BSE), Hybrid Watershed Algorithm (HWA) and a Multi-Atlas Propagation and Segmentation (MAPS) technique we have previously developed for hippocampal segmentation. The four methods were applied to extract whole brains from 682 1.5T and 157 3T T1-weighted MR baseline images from the Alzheimer’s Disease Neuroimaging Initiative database. Semi-automated brain segmentations with manual editing and checking were used as the gold-standard to compare with the results. The median Jaccard index of MAPS was higher than HWA, BET and BSE in 1.5T and 3T scans (p < 0.05, all tests), and the 1st-99th centile range of the Jaccard index of MAPS was smaller than HWA, BET and BSE in 1.5T and 3T scans (p < 0.05, all tests). HWA and MAPS were found to be best at including all brain tissues (median false negative rate ≤ 0.010% for 1.5T scans and ≤ 0.019% for 3T scans, both methods). The median Jaccard index of MAPS were similar in both 1.5T and 3T scans, whereas those of BET, BSE and HWA were higher in 1.5T scans than 3T scans (p < 0.05, all tests). We found that the diagnostic group had a small effect on the median Jaccard index of all four methods. In conclusion, MAPS had relatively high accuracy and low variability compared to HWA, BET and BSE in MR scans with and without atrophy. PMID:21195780

  6. Generating Accurate Urban Area Maps from Nighttime Satellite (DMSP/OLS) Data

    NASA Technical Reports Server (NTRS)

    Imhoff, Marc; Lawrence, William; Elvidge, Christopher

    2000-01-01

    There has been an increasing interest by the international research community to use the nighttime acquired "city-lights" data sets collected by the US Defense Meteorological Satellite Program's Operational Linescan system to study issues relative to urbanization. Many researchers are interested in using these data to estimate human demographic parameters over large areas and then characterize the interactions between urban development , natural ecosystems, and other aspects of the human enterprise. Many of these attempts rely on an ability to accurately identify urbanized area. However, beyond the simple determination of the loci of human activity, using these data to generate accurate estimates of urbanized area can be problematic. Sensor blooming and registration error can cause large overestimates of urban land based on a simple measure of lit area from the raw data. We discuss these issues, show results of an attempt to do a historical urban growth model in Egypt, and then describe a few basic processing techniques that use geo-spatial analysis to threshold the DMSP data to accurately estimate urbanized areas. Algorithm results are shown for the United States and an application to use the data to estimate the impact of urban sprawl on sustainable agriculture in the US and China is described.

  7. nuMap: a web platform for accurate prediction of nucleosome positioning.

    PubMed

    Alharbi, Bader A; Alshammari, Thamir H; Felton, Nathan L; Zhurkin, Victor B; Cui, Feng

    2014-10-01

    Nucleosome positioning is critical for gene expression and of major biological interest. The high cost of experimentally mapping nucleosomal arrangement signifies the need for computational approaches to predict nucleosome positions at high resolution. Here, we present a web-based application to fulfill this need by implementing two models, YR and W/S schemes, for the translational and rotational positioning of nucleosomes, respectively. Our methods are based on sequence-dependent anisotropic bending that dictates how DNA is wrapped around a histone octamer. This application allows users to specify a number of options such as schemes and parameters for threading calculation and provides multiple layout formats. The nuMap is implemented in Java/Perl/MySQL and is freely available for public use at http://numap.rit.edu. The user manual, implementation notes, description of the methodology and examples are available at the site. PMID:25220945

  8. Adaptive Analytic Mapping Procedures for Simple and Accurate Calculation of Scattering Lengths and Photoassociation Absorption Intensities

    NASA Astrophysics Data System (ADS)

    Le Roy, Robert J.; Meshkov, Vladimir V.; Stolyarov, Andrej V.

    2009-06-01

    We have shown that one and two-parameter analytical mapping functions such as r(y;bar{r}, α)=bar{r}[1 + {1}/{α} tan(π y/2)] and r(y;bar{r})=bar{r} [ {1+ y}/{1-y} ] transform the conventional radial Schrödinger equation into equivalent alternate forms {d^2φ(y)}/{dy^2} = [{π^2}/{4}+({2μ}/ {hbar^2} ) g^2(y) [E - U(r(y))

  9. Development of base maps' role in soil mapping

    NASA Astrophysics Data System (ADS)

    Miller, Brad; Brevik, Eric

    2014-05-01

    One of the ultimate goals of soil science is the production of accurate soil maps, but historically these thematic maps have relied upon base maps for positional reference and later for parameters that help predict soil properties. This presentation reviews the history of base maps and the dependence of soil mapping on them. The availability of geographic technology for producing these base maps has constrained and directed the geographic study of soil. A lack of accurate methods for determining location limited early geographic description of soils to narratives. The availability of accurate topographic maps in the late 18th century, fueled by governments' interests in documenting national boundaries and popular interest in world atlases, provided the first base maps for soil geographers. These soil maps primarily used the topographic maps as a spatial reference onto which the thematic details were drawn. Due to the late start of a systematic topographic survey in the United States, early Soil Survey maps depended upon plat maps for spatial reference. The adoption of aerial photographs in the process of soil mapping increased the role of base maps as predictive parameters. In the current geospatial revolution, global positioning systems and geographic information systems have nearly replaced the need for base maps to provide spatial reference. Today, base maps are more likely to be used as parameters in landscape models for predicting the spatial distribution of soil properties and classes. As model parameters for digital soil maps, base maps constitute the library of predictive variables and constrain the supported resolution of the soil map. This change in the relationship between base maps and the soil map is a paradigm shift that affects fundamental definitions of geography, such as scale, resolution, and detectable features. These concepts are the essential tools used to study the spatial characteristics of Earth Systems.

  10. Oxygen-enhanced MRI accurately identifies, quantifies, and maps tumor hypoxia in preclinical cancer models

    PubMed Central

    O’Connor, James PB; Boult, Jessica KR; Jamin, Yann; Babur, Muhammad; Finegan, Katherine G; Williams, Kaye J; Little, Ross A; Jackson, Alan; Parker, Geoff JM; Reynolds, Andrew R; Waterton, John C; Robinson, Simon P

    2015-01-01

    There is a clinical need for non-invasive biomarkers of tumor hypoxia for prognostic and predictive studies, radiotherapy planning and therapy monitoring. Oxygen enhanced MRI (OE-MRI) is an emerging imaging technique for quantifying the spatial distribution and extent of tumor oxygen delivery in vivo. In OE-MRI, the longitudinal relaxation rate of protons (ΔR1) changes in proportion to the concentration of molecular oxygen dissolved in plasma or interstitial tissue fluid. Therefore, well-oxygenated tissues show positive ΔR1. We hypothesized that the fraction of tumor tissue refractory to oxygen challenge (lack of positive ΔR1, termed “Oxy-R fraction”) would be a robust biomarker of hypoxia in models with varying vascular and hypoxic features. Here we demonstrate that OE-MRI signals are accurate, precise and sensitive to changes in tumor pO2 in highly vascular 786-0 renal cancer xenografts. Furthermore, we show that Oxy-R fraction can quantify the hypoxic fraction in multiple models with differing hypoxic and vascular phenotypes, when used in combination with measurements of tumor perfusion. Finally, Oxy-R fraction can detect dynamic changes in hypoxia induced by the vasomodulator agent hydralazine. In contrast, more conventional biomarkers of hypoxia (derived from blood oxygenation-level dependent MRI and dynamic contrast-enhanced MRI) did not relate to tumor hypoxia consistently. Our results show that the Oxy-R fraction accurately quantifies tumor hypoxia non-invasively and is immediately translatable to the clinic. PMID:26659574

  11. An accurate Galactic N(sub H) map of the north ecliptic pole

    NASA Technical Reports Server (NTRS)

    Elvis, Martin; Lockman, Felix J.; Fassnacht, C.

    1994-01-01

    The Galactic HI column density was measured at 21 min angular resolution over an 8 deg x 9 deg region centered on the north ecliptic pole. Over the region N(sub H) varies smoothly between 3 x 10(exp 20) atoms/sq cm and 8 x 10(exp 20) atoms/sq cm; some structure is seen over most of the map on an 0.5 - 1 deg scale. There are other possible sources of interstellar opacity in this direction which may add an equivalent 10(exp 20)/sq cm of HI. We evaluate the effect of uncertainties in the HI column density on implied X-ray fluxes of extragalactic objects.

  12. Spatio-temporal assessment of aqueous habitat dynamics at the Danube river floodplain based on historical topographic maps and remote sensing data

    NASA Astrophysics Data System (ADS)

    Farkas-Iványi, Kinga; Mészáros, János; Pásztor, László

    2016-04-01

    The basic requirements of sustainable restoration along rivers is the detection and evaluation of the historical changes in the landscape shaping processes. Identification of historical changes and habitat dynamics are essential criteria for understanding the geomorphological response of the fluvial system to flood discharges. Danube had three main types of channel adjustment in Szigetköz at the border of Hungary and Slovakia; the anabranching river section with medium flow velocity properties, the anastomosing river section with less intensive runoff conditions, and the meandering river section, with slow flow velocity properties. Our aim was to define, which section is the most responsive for near-natural and anthropogenic changes and which is the most stubborn against them, or see if they react in the same way. The parameters of the analysis were fluvial forms, their erosion, types of vegetation and nodes of bars and islands. The analysis was based on georeferenced topographic maps and remote sensing data of eight different dates from the last 200 years. The active channel (AC = main channel + side arms + backwaters + gravel/sand bars) and the habitat composition (HC = % of individual habitat types of AC) were defined for the whole time scale for extracting the most dynamic nodes of the active zone. After we were tracing down the areas of habitat succession and regeneration, by the comparison of adjacent time periods, we concluded that the three different channel types react differently for near-natural changes (e.g. the rejuvenation of the anabranching area was twice intensive than the anastomosing river section before channelization), but react with the same processes (e.g. terrestrialisation) for anthropogenic effects. Our poster will represent these preliminary results besides used datasets and methods.

  13. Accurate multi-source forest species mapping using the multiple spectral-spatial classification approach

    NASA Astrophysics Data System (ADS)

    Stavrakoudis, Dimitris; Gitas, Ioannis; Karydas, Christos; Kolokoussis, Polychronis; Karathanassi, Vassilia

    2015-10-01

    This paper proposes an efficient methodology for combining multiple remotely sensed imagery, in order to increase the classification accuracy in complex forest species mapping tasks. The proposed scheme follows a decision fusion approach, whereby each image is first classified separately by means of a pixel-wise Fuzzy-Output Support Vector Machine (FO-SVM) classifier. Subsequently, the multiple results are fused according to the so-called multiple spectral- spatial classifier using the minimum spanning forest (MSSC-MSF) approach, which constitutes an effective post-regularization procedure for enhancing the result of a single pixel-based classification. For this purpose, the original MSSC-MSF has been extended in order to handle multiple classifications. In particular, the fuzzy outputs of the pixel-based classifiers are stacked and used to grow the MSF, whereas the markers are also determined considering both classifications. The proposed methodology has been tested on a challenging forest species mapping task in northern Greece, considering a multispectral (GeoEye) and a hyper-spectral (CASI) image. The pixel-wise classifications resulted in overall accuracies (OA) of 68.71% for the GeoEye and 77.95% for the CASI images, respectively. Both of them are characterized by high levels of speckle noise. Applying the proposed multi-source MSSC-MSF fusion, the OA climbs to 90.86%, which is attributed both to the ability of MSSC-MSF to tackle the salt-and-pepper effect, as well as the fact that the fusion approach exploits the relative advantages of both information sources.

  14. Determining the Topographic Manifestation of Widespread Landsliding with High Resolution Airborne Laser Swath Mapping (ALSM) Data, South Fork Eel River, Northern California.

    NASA Astrophysics Data System (ADS)

    Mackey, B. H.; Roering, J. J.; Dietrich, W. E.

    2005-12-01

    Long-term average uplift rates in Northern California are as high as 1-5mm/yr, yet in many areas the relief remains modest due to pervasive slope instability. Here, we analyze deep-seated hillslope instability using an extensive ALSM dataset covering 230 km2 of the South Fork Eel River in Northern California. Through a combination of geomorphic mapping and statistical terrain analysis, we identify ubiquitous deep-seated landslide and earthflow features, whose locations are strongly correlated with underlying Franciscan melange lithology, large-scale structural features, and connectivity to channels. In contrast to the well-ordered ridge-valley topography of unfailed hillslopes, deep-seated landslides present a rough or hummocky surface due to movement and internal deformation of the sliding mass. Such landslides are therefore ideally suited to recognition by various techniques that statistically measure small-scale variations in topographic roughness. To objectively identify and characterize landslide features using a process-based framework, we employed surface roughness algorithms and hillslope hydraulic models. Our techniques are clearly able to identify and delineate the extent and surface features of landslide prone terrain. We find a high correlation between slope instability and low values of drainage area per unit contour width (a/b). Active landslides have a marked impact on the hillslope hydrology by retarding the ability of the channels to incise and establish a drainage network, thus promoting large areas with significantly low a/b values compared to surrounding unfailed terrain. The landslides and earthflows are a major geomorphic process in the study area, as greater than 50 percent of the landscape is affected. Flows with a rougher surface, which we interpret to be more active than flows with smoother surfaces, are proximate to active stream channels suggesting undercutting of the toe is a primary control on the rate of slide movement. By analyzing

  15. Visual Mapping of Sedimentary Facies Can Yield Accurate And Geomorphically Meaningful Results at Morphological Unit to River Segment Scales

    NASA Astrophysics Data System (ADS)

    Pasternack, G. B.; Wyrick, J. R.; Jackson, J. R.

    2014-12-01

    Long practiced in fisheries, visual substrate mapping of coarse-bedded rivers is eschewed by geomorphologists for inaccuracy and limited sizing data. Geomorphologists perform time-consuming measurements of surficial grains, with the few locations precluding spatially explicit mapping and analysis of sediment facies. Remote sensing works for bare land, but not vegetated or subaqueous sediments. As visual systems apply the log2 Wentworth scale made for sieving, they suffer from human inability to readily discern those classes. We hypothesized that size classes centered on the PDF of the anticipated sediment size distribution would enable field crews to accurately (i) identify presence/absence of each class in a facies patch and (ii) estimate the relative amount of each class to within 10%. We first tested 6 people using 14 measured samples with different mixtures. Next, we carried out facies mapping for ~ 37 km of the lower Yuba River in California. Finally, we tested the resulting data to see if it produced statistically significant hydraulic-sedimentary-geomorphic results. Presence/absence performance error was 0-4% for four people, 13% for one person, and 33% for one person. The last person was excluded from further effort. For the abundance estimation performance error was 1% for one person, 7-12% for three people, and 33% for one person. This last person was further trained and re-tested. We found that the samples easiest to visually quantify were unimodal and bimodal, while those most difficult had nearly equal amounts of each size. This confirms psychological studies showing that humans have a more difficult time quantifying abundances of subgroups when confronted with well-mixed groups. In the Yuba, mean grain size decreased downstream, as is typical for an alluvial river. When averaged by reach, mean grain size and bed slope were correlated with an r2 of 0.95. At the morphological unit (MU) scale, eight in-channel bed MU types had an r2 of 0.90 between mean

  16. IGS-global ionospheric maps for accurate computation of GPS single- frequency ionospheric delay-simulation study

    NASA Astrophysics Data System (ADS)

    Farah, A.

    The Ionospheric delay is still one of the largest sources of error that affects the positioning accuracy of any satellite positioning system. This problem could be solved due to the dispersive nature of the Ionosphere by combining simultaneous measurements of signals at two different frequencies but it is still there for single- frequency users. Much effort has been made in establishing models for single- frequency users to make this effect as small as possible. These models vary in accuracy, input data and computational complexity, so the choice between the different models depends on the individual circumstances of the user. From the simulation point of view, the model needed should be accurate with a global coverage and good description to the Ionosphere's variable nature with both time and location. The author reviews some of these established models, starting with the BENT model, the Klobuchar model and the IRI (International Reference Ionosphere) model. Since quiet a long time, Klobuchar model considers the most widely used model ever in this field, due to its simplicity and time saving. Any GPS user could find Klobuchar model's coefficients in the broadcast navigation message. CODE, Centre for Orbit Determination in Europe provides a new set of coefficients for Klobuchar model, which gives more accurate results for the Ionospheric delay computation. IGS (International GPS Service) services include providing GPS community with a global Ionospheric maps in IONEX-format (IONosphere Map Exchange format) which enables the computation of the Ionospheric delay at the desired location and time. The study was undertaken from GPS-data simulation point of view. The aim was to select a model for the simulation of GPS data that gives a good description of the Ionosphere's nature with a high degree of accuracy in computing the Ionospheric delay that yields to better-simulated data. A new model developed by the author based on IGS global Ionospheric maps. A comparison

  17. Topographic organizations of taste-responsive neurons in the parabrachial nucleus of C57BL/6J mice: An electrophysiological mapping study.

    PubMed

    Tokita, K; Boughter, J D

    2016-03-01

    The activities of 178 taste-responsive neurons were recorded extracellularly from the parabrachial nucleus (PbN) in the anesthetized C57BL/6J mouse. Taste stimuli included those representative of five basic taste qualities, sweet, salty, sour, bitter and umami. Umami synergism was represented by all sucrose-best and sweet-sensitive sodium chloride-best neurons. Mediolaterally the PbN was divided into medial, brachium conjunctivum (BC) and lateral subdivisions while rostrocaudally the PbN was divided into rostral and caudal subdivisions for mapping and reconstruction of recording sites. Neurons in the medial and BC subdivisions had a significantly greater magnitude of response to sucrose and to the mixture of monopotassium glutamate and inosine monophosphate than those found in the lateral subdivision. In contrast, neurons in the lateral subdivision possessed a more robust response to quinine hydrochloride. Rostrocaudally no difference was found in the mean magnitude of response. Analysis on the distribution pattern of neuron types classified by their best stimulus revealed that the proportion of neuron types in the medial vs. lateral and BC vs. lateral subdivisions was significantly different, with a greater amount of sucrose-best neurons found medially and within the BC, and a greater amount of sodium chloride-, citric acid- and quinine hydrochloride-best neurons found laterally. There was no significant difference in the neuron-type distribution between rostral and caudal PbN. We also assessed breadth of tuning in these neurons by calculating entropy (H) and noise-to-signal (N/S) ratio. The mean N/S ratio of all neurons (0.43) was significantly lower than that of H value (0.64). Neurons in the caudal PbN had a significantly higher H value than in the rostral PbN. In contrast, mean N/S ratios were not different both mediolaterally and rostrocaudally. These results suggest that although there is overlap in taste quality representation in the mouse PbN, taste

  18. A scalable and accurate method for classifying protein-ligand binding geometries using a MapReduce approach.

    PubMed

    Estrada, T; Zhang, B; Cicotti, P; Armen, R S; Taufer, M

    2012-07-01

    We present a scalable and accurate method for classifying protein-ligand binding geometries in molecular docking. Our method is a three-step process: the first step encodes the geometry of a three-dimensional (3D) ligand conformation into a single 3D point in the space; the second step builds an octree by assigning an octant identifier to every single point in the space under consideration; and the third step performs an octree-based clustering on the reduced conformation space and identifies the most dense octant. We adapt our method for MapReduce and implement it in Hadoop. The load-balancing, fault-tolerance, and scalability in MapReduce allow screening of very large conformation spaces not approachable with traditional clustering methods. We analyze results for docking trials for 23 protein-ligand complexes for HIV protease, 21 protein-ligand complexes for Trypsin, and 12 protein-ligand complexes for P38alpha kinase. We also analyze cross docking trials for 24 ligands, each docking into 24 protein conformations of the HIV protease, and receptor ensemble docking trials for 24 ligands, each docking in a pool of HIV protease receptors. Our method demonstrates significant improvement over energy-only scoring for the accurate identification of native ligand geometries in all these docking assessments. The advantages of our clustering approach make it attractive for complex applications in real-world drug design efforts. We demonstrate that our method is particularly useful for clustering docking results using a minimal ensemble of representative protein conformational states (receptor ensemble docking), which is now a common strategy to address protein flexibility in molecular docking. PMID:22658682

  19. Egocentrism and Map Reading Ability.

    ERIC Educational Resources Information Center

    Towler, John O.

    Egocentrism was investigated as an influencing factor in the development of the perceptual abilities needed to understand and interpret topographic maps. Attainment of an adequate concept of space, and the ability to accurately perceive spatial relationships (perspectives) are considered fundamental. Piaget and Inhelder identified three stages of…

  20. Reconstruction of late Holocene glacier retreat and relevant climatic and topographic patterns in southeastern Tibet by glacier mapping and equilibrium line altitude calculation

    NASA Astrophysics Data System (ADS)

    Loibl, David; Lehmkuhl, Frank

    2014-05-01

    Temperate glaciers in the eastern Nyainqêntanglha range, southeastern Tibet, are highly sensitive to climate change and are therefore of particular high interest for research on late Holocene changes of the monsoonal climate in High Asia. However, due to the remoteness of the area, the scarcity of empirical data, and the challenges to remote sensing work posed by cloud and snow cover, knowledge about the glacier dynamics and changes is still very limited. We applied a remote sensing approach that allowed a comprehensive regional glacier survey despite the few available data. Geomorphologic characteristics, distribution and late Holocene changes of 1964 glaciers were mapped from one of the few appropriate late summer satellite images: a Landsat ETM+ scene from September 23, 1999. The glacier dataset was subsequently parameterized by DEM supported measurements. Complex climate-relief-glacier interactions were studied in detail for three large glaciers in neighboring valleys. Despite their spatial proximity, these display strong heterogeneity in terms of catchment morphology, debris cover, and glacier characteristics. The results of this case study then provided the conceptual basis to use geomorphological evidence, i.e. trimlines and latero-frontal moraines, to obtain quantitative data on the changes since the Little Ice Age (LIA) maximum glacier advance. Statistical analysis of glacier length change revealed an average retreat of ~ 40 % and a trend towards stronger retreat for smaller glaciers. An evaluation of different methods to calculate equilibrium line altitudes (ELAs) indicates that an optimized toe-to-ridge altitude method (TRAM) outperforms other methods in settings with complex topography and a lack of mass-balance measurements. However, a large number of glacier measurements is crucial for high quality TRAM results and special attention has to be paid to different morphological glacier characteristics: debris-cover, reconstitution, valley floor

  1. Mapping of photon distribution and imaging of MR-derived anatomically accurate optical models of the female breast

    NASA Astrophysics Data System (ADS)

    Barbour, San-Lian S.; Barbour, Randall L.; Koo, Ping C.; Graber, Harry L.; Chang, Jenghwa

    1995-05-01

    We have computed optical images of the female breast based on analysis of tomographic data obtained from simulated time-independent optical measurements of anatomically accurate maps derived from segmented 3D magnetic resonance (MR) images. Images were segmented according to the measured MR contrast levels for fat and parenchymal tissue from T1 weighted acquisitions. Computed images were obtained from analysis of solutions to the forward problem for breasts containing 'added pathologies', representing tumors, to breasts lacking these inclusions. Both breast size and its optical properties have been examined in tissue. In each case, two small simulated tumors were 'added' to the background issue. Values of absorption and scattering coefficients of the tumors have been examined that are both greater and less than the surrounding tissue. Detector responses and the required imaging operators were computed by numerically solving the diffusion equation for inhomogeneous media. Detectors were distributed uniformly, in a circular fashion, around the breast in a plane positioned parallel and half-way between the chest wall and the nipple. A total of 20 sources were used, and for each 20 detectors. Reconstructed images were obtained by solving a linear perturbation equation derived from transport theory. Three algorithms were tested to solve the perturbation equation and include, the methods of conjugate gradient decent (CGD), projection onto convex sets (POCS), and simultaneous algebraic reconstruction technique (SART). Results obtained showed that in each case, high quality reconstructions were obtained. The computed images correctly resolved and identified the spatial position of the two tumors. Additional studies showed that computed images were stable to large systematic errors in the imaging operators and to added noise. Further, examination of the computed detector readings indicate that images of tissue up to approximately 10 cm in thickness should be possible. The

  2. SU-D-18C-05: Variable Bolus Arterial Spin Labeling MRI for Accurate Cerebral Blood Flow and Arterial Transit Time Mapping

    SciTech Connect

    Johnston, M; Jung, Y

    2014-06-01

    Purpose: Arterial spin labeling (ASL) is an MRI perfusion imaging method from which quantitative cerebral blood flow (CBF) maps can be calculated. Acquisition with variable post-labeling delays (PLD) and variable TRs allows for arterial transit time (ATT) mapping and leads to more accurate CBF quantification with a scan time saving of 48%. In addition, T1 and M0 maps can be obtained without a separate scan. In order to accurately estimate ATT and T1 of brain tissue from the ASL data, variable labeling durations were invented, entitled variable-bolus ASL. Methods: All images were collected on a healthy subject with a 3T Siemens Skyra scanner. Variable-bolus Psuedo-continuous ASL (PCASL) images were collected with 7 TI times ranging 100-4300ms in increments of 700ms with TR ranging 1000-5200ms. All boluses were 1600ms when the TI allowed, otherwise the bolus duration was 100ms shorter than the TI. All TI times were interleaved to reduce sensitivity to motion. Voxel-wise T1 and M0 maps were estimated using a linear least squares fitting routine from the average singal from each TI time. Then pairwise subtraction of each label/control pair and averaging for each TI time was performed. CBF and ATT maps were created using the standard model by Buxton et al. with a nonlinear fitting routine using the T1 tissue map. Results: CBF maps insensitive to ATT were produced along with ATT maps. Both maps show patterns and averages consistent with literature. The T1 map also shows typical T1 contrast. Conclusion: It has been demonstrated that variablebolus ASL produces CBF maps free from the errors due to ATT and tissue T1 variations and provides M0, T1, and ATT maps which have potential utility. This is accomplished with a single scan in a feasible scan time (under 6 minutes) with low sensivity to motion.

  3. Shifted Hamming distance: a fast and accurate SIMD-friendly filter to accelerate alignment verification in read mapping

    PubMed Central

    Xin, Hongyi; Greth, John; Emmons, John; Pekhimenko, Gennady; Kingsford, Carl; Alkan, Can; Mutlu, Onur

    2015-01-01

    Motivation: Calculating the edit-distance (i.e. minimum number of insertions, deletions and substitutions) between short DNA sequences is the primary task performed by seed-and-extend based mappers, which compare billions of sequences. In practice, only sequence pairs with a small edit-distance provide useful scientific data. However, the majority of sequence pairs analyzed by seed-and-extend based mappers differ by significantly more errors than what is typically allowed. Such error-abundant sequence pairs needlessly waste resources and severely hinder the performance of read mappers. Therefore, it is crucial to develop a fast and accurate filter that can rapidly and efficiently detect error-abundant string pairs and remove them from consideration before more computationally expensive methods are used. Results: We present a simple and efficient algorithm, Shifted Hamming Distance (SHD), which accelerates the alignment verification procedure in read mapping, by quickly filtering out error-abundant sequence pairs using bit-parallel and SIMD-parallel operations. SHD only filters string pairs that contain more errors than a user-defined threshold, making it fully comprehensive. It also maintains high accuracy with moderate error threshold (up to 5% of the string length) while achieving a 3-fold speedup over the best previous algorithm (Gene Myers’s bit-vector algorithm). SHD is compatible with all mappers that perform sequence alignment for verification. Availability and implementation: We provide an implementation of SHD in C with Intel SSE instructions at: https://github.com/CMU-SAFARI/SHD. Contact: hxin@cmu.edu, calkan@cs.bilkent.edu.tr or onur@cmu.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25577434

  4. A fully automatic tool to perform accurate flood mapping by merging remote sensing imagery and ancillary data

    NASA Astrophysics Data System (ADS)

    D'Addabbo, Annarita; Refice, Alberto; Lovergine, Francesco; Pasquariello, Guido

    2016-04-01

    Flooding is one of the most frequent and expansive natural hazard. High-resolution flood mapping is an essential step in the monitoring and prevention of inundation hazard, both to gain insight into the processes involved in the generation of flooding events, and from the practical point of view of the precise assessment of inundated areas. Remote sensing data are recognized to be useful in this respect, thanks to the high resolution and regular revisit schedules of state-of-the-art satellites, moreover offering a synoptic overview of the extent of flooding. In particular, Synthetic Aperture Radar (SAR) data present several favorable characteristics for flood mapping, such as their relative insensitivity to the meteorological conditions during acquisitions, as well as the possibility of acquiring independently of solar illumination, thanks to the active nature of the radar sensors [1]. However, flood scenarios are typical examples of complex situations in which different factors have to be considered to provide accurate and robust interpretation of the situation on the ground: the presence of many land cover types, each one with a particular signature in presence of flood, requires modelling the behavior of different objects in the scene in order to associate them to flood or no flood conditions [2]. Generally, the fusion of multi-temporal, multi-sensor, multi-resolution and/or multi-platform Earth observation image data, together with other ancillary information, seems to have a key role in the pursuit of a consistent interpretation of complex scenes. In the case of flooding, distance from the river, terrain elevation, hydrologic information or some combination thereof can add useful information to remote sensing data. Suitable methods, able to manage and merge different kind of data, are so particularly needed. In this work, a fully automatic tool, based on Bayesian Networks (BNs) [3] and able to perform data fusion, is presented. It supplies flood maps

  5. (abstract) Topographic Signatures in Geology

    NASA Technical Reports Server (NTRS)

    Farr, Tom G.; Evans, Diane L.

    1996-01-01

    Topographic information is required for many Earth Science investigations. For example, topography is an important element in regional and global geomorphic studies because it reflects the interplay between the climate-driven processes of erosion and the tectonic processes of uplift. A number of techniques have been developed to analyze digital topographic data, including Fourier texture analysis. A Fourier transform of the topography of an area allows the spatial frequency content of the topography to be analyzed. Band-pass filtering of the transform produces images representing the amplitude of different spatial wavelengths. These are then used in a multi-band classification to map units based on their spatial frequency content. The results using a radar image instead of digital topography showed good correspondence to a geologic map, however brightness variations in the image unrelated to topography caused errors. An additional benefit to the use of Fourier band-pass images for the classification is that the textural signatures of the units are quantative measures of the spatial characteristics of the units that may be used to map similar units in similar environments.

  6. Digital topographic map showing the extents of glacial ice and perennial snowfields at Mount Rainier, Washington, based on the LiDAR survey of September 2007 to October 2008

    USGS Publications Warehouse

    Robinson, Joel E.; Sisson, Thomas W.; Swinney, Darin D.

    2010-01-01

    In response to severe flooding in November 2006, the National Park Service contracted for a high-resolution aerial Light Detection and Ranging (LiDAR) topographic survey of Mount Rainier National Park, Washington. Due to inclement weather, this survey was performed in two stages: early September 2007 and September-October 2008. The total surveyed area of 241,585 acres includes an approximately 100-m-wide buffer zone around the Park to ensure complete coverage and adequate point densities at survey edges. Final results averaged 5.73 laser first return points/m2 over forested and high-elevation terrain, with a vertical accuracy of 3.7 cm on bare road surfaces and mean relative accuracy of 11 cm, based on comparisons between flightlines. Bare-earth topography, as developed by the contractor, is included in this release. A map of the 2007-2008 limits of glaciers and perennial snowfields was developed by digitizing 1:2,000 to 1:5,000 slope and shaded-relief images derived from the LiDAR topography. Edges of snow and exposed ice are readily seen in such images as sharp changes in surface roughness and slope. Ice mantled by moraine can be distinguished by the moraine's distinctly high roughness due to ice motion and melting, local exposures of smooth ice, and commonly by the presence of crevasses and shear boundaries. A map of the 1970 limits of ice and perennial snow was also developed by digitizing the snow and ice perimeters as depicted on the hydrologic separates used to produce the 1:24,000 topographic maps of the Mount Rainier region. These maps, produced in 1971, were derived from September 1970 aerial photographs. Boundaries between adjacent glacier systems were estimated and mapped from drainage divides, including partly emergent rock ridges, lines of diverging slope, and medial moraines. This data release contains the bare-earth LiDAR data as an ESRI grid file (DS549-Rainier_LiDAR.zip), the glacial limits derived from the USGS 1970 aerial photographs of the

  7. Reinventing the National Topographic Database

    NASA Astrophysics Data System (ADS)

    Jakobsson, A.; Ilves, R.

    2016-06-01

    The National Land Survey (NLS) has had a digital topographic database (TDB) since 1992. Many of its features are based on the Basic Map created by M. Kajamaa in 1947, mapping first completed in 1977. The basis for the renewal of the TDB begun by investigating the value of the TDB, a study made by the Aalto University in 2014 and a study on the new TDB system 2030 published by the Ministry of Agriculture in 2015. As a result of these studies the NLS set up a programme for creating a new National Topographic Database (NTDB) in beginning of 2015. First new version should be available in 2019. The new NTDB has following key features: 1) it is based on processes where data is naturally maintained, 2) it is quality managed, 3) it has persistent Ids, 4) it supports 3D, 4D, 5) it is based on standards. The technical architecture is based on interoperable modules. A website for following the development of the NTDB can be accessed for more information: http://kmtk.maanmittauslaitos.fi/.

  8. Objective extraction of channel heads from high resolution topographic data

    NASA Astrophysics Data System (ADS)

    Clubb, Fiona J.; Mudd, Simon M.; Milodowski, David T.; Hurst, Martin D.; Slater, Louise J.

    2014-05-01

    Fluvial landscapes are dissected by channels, and at their upstream termini are channel heads. Accurate reconstruction of the fluvial domain is fundamental to understanding runoff generation, storm hydrology, biogeochemical cycling and landscape evolution. Many methods have been proposed for predicting channel head locations using topographic data, yet none have been tested against a robust field dataset of mapped channel heads across multiple landscapes. In this study, four methods of channel head prediction were tested against field data from four sites with high-resolution (1m) DEMs: slope-area scaling relationships; GeoNet 2.0 [Passalacqua et al., 2010]; a contour curvature technique proposed by Pelletier [2013]; and the DrEICH algorithm, a new method presented by Clubb et al. [in prep]. Our method identifies the change from channel to hillslope topography along a profile using a transformed longitudinal coordinate system. It requires only two user-defined parameters: the m/n value, which can be determined via independent statistical analysis; and the number of linked pixels used to identify a first-order valley. Slope-area plots are traditionally used to identify the fluvial-hillslope transition, but we observe no clear relationship between this transition and the field-mapped channel heads. Of the four methods assessed, Pelletier's [2013] tangential curvature method and the DrEICH method most accurately reproduce the measured channel heads in all four field sites (Feather River CA, Mid Bailey Run OH, Indian Creek OH, Piedmont VA), with mean errors of -11, -7, 5 and -24 meters and 34, 3, 12 and -58 meters respectively. Negative values indicate channel heads located upslope of those mapped in the field. Importantly, these two independent methods, one based on contour curvature and the other based on the geometry of longitudinal profiles, produce mutually consistent estimates, providing two tests of channel head locations based on independent topographic

  9. USGS 1:24,000 TOPOGRAPHIC QUADRANGLE SERIES INDEXES

    EPA Science Inventory

    USGS 1:24,000 Topographic Quadrangle Series Indexes represents the geographic extent of USGS 1:24,000 topographic maps (7.5- by 7.5-minute quadrangles) for the coterminous U.S. forty-eight states and District of Columbia.

  10. An empirical study on the utility of BRDF model parameters and topographic parameters for mapping vegetation in a semi-arid region with MISR imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multi-angle remote sensing has been proved useful for mapping vegetation community types in desert regions. Based on Multi-angle Imaging Spectro-Radiometer (MISR) multi-angular images, this study compares roles played by Bidirectional Reflectance Distribution Function (BRDF) model parameters with th...

  11. Ultrahigh resolution topographic mapping of Mars with MRO HiRISE stereo images: Meter-scale slopes of candidate Phoenix landing sites

    NASA Astrophysics Data System (ADS)

    Kirk, R. L.; Howington-Kraus, E.; Rosiek, M. R.; Anderson, J. A.; Archinal, B. A.; Becker, K. J.; Cook, D. A.; Galuszka, D. M.; Geissler, P. E.; Hare, T. M.; Holmberg, I. M.; Keszthelyi, L. P.; Redding, B. L.; Delamere, W. A.; Gallagher, D.; Chapel, J. D.; Eliason, E. M.; King, R.; McEwen, A. S.

    2008-11-01

    The objectives of this paper are twofold: first, to report our estimates of the meter-to-decameter-scale topography and slopes of candidate landing sites for the Phoenix mission, based on analysis of Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images with a typical pixel scale of 3 m and Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) images at 0.3 m pixel-1 and, second, to document in detail the geometric calibration, software, and procedures on which the photogrammetric analysis of HiRISE data is based. A combination of optical design modeling, laboratory observations, star images, and Mars images form the basis for software in the U.S. Geological Survey Integrated Software for Imagers and Spectrometers (ISIS) 3 system that corrects the images for a variety of distortions with single-pixel or subpixel accuracy. Corrected images are analyzed in the commercial photogrammetric software SOCET SET (® BAE Systems), yielding digital topographic models (DTMs) with a grid spacing of 1 m (3-4 pixels) that require minimal interactive editing. Photoclinometry yields DTMs with single-pixel grid spacing. Slopes from MOC and HiRISE are comparable throughout the latitude zone of interest and compare favorably with those where past missions have landed successfully; only the Mars Exploration Rover (MER) B site in Meridiani Planum is smoother. MOC results at multiple locations have root-mean-square (RMS) bidirectional slopes of 0.8-4.5° at baselines of 3-10 m. HiRISE stereopairs (one per final candidate site and one in the former site) yield 1.8-2.8° slopes at 1-m baseline. Slopes at 1 m from photoclinometry are also in the range 2-3° after correction for image blur. Slopes exceeding the 16° Phoenix safety limit are extremely rare.

  12. Ultrahigh resolution topographic mapping of Mars with MRO HiRISE stereo images: Meter-scale slopes of candidate Phoenix landing sites

    USGS Publications Warehouse

    Kirk, R.L.; Howington-Kraus, E.; Rosiek, M.R.; Anderson, J.A.; Archinal, B.A.; Becker, K.J.; Cook, D.A.; Galuszka, D.M.; Geissler, P.E.; Hare, T.M.; Holmberg, I.M.; Keszthelyi, L.P.; Redding, B.L.; Delamere, W.A.; Gallagher, D.; Chapel, J.D.; Eliason, E.M.; King, R.; McEwen, A.S.

    2009-01-01

    The objectives of this paper are twofold: first, to report our estimates of the meter-to-decameter-scale topography and slopes of candidate landing sites for the Phoenix mission, based on analysis of Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images with a typical pixel scale of 3 m and Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) images at 0.3 m pixel-1 and, second, to document in detail the geometric calibration, software, and procedures on which the photogrammetric analysis of HiRISE data is based. A combination of optical design modeling, laboratory observations, star images, and Mars images form the basis for software in the U.S. Geological Survey Integrated Software for Imagers and Spectrometers (ISIS) 3 system that corrects the images for a variety of distortions with single-pixel or subpixel accuracy. Corrected images are analyzed in the commercial photogrammetric software SOCET SET (??BAE Systems), yielding digital topographic models (DTMs) with a grid spacing of 1 m (3-4 pixels) that require minimal interactive editing. Photoclinometry yields DTMs with single-pixel grid spacing. Slopes from MOC and HiRISE are comparable throughout the latitude zone of interest and compare favorably with those where past missions have landed successfully; only the Mars Exploration Rover (MER) B site in Meridiani Planum is smoother. MOC results at multiple locations have root-mean-square (RMS) bidirectional slopes of 0.8-4.5?? at baselines of 3-10 m. HiRISE stereopairs (one per final candidate site and one in the former site) yield 1.8-2.8?? slopes at 1-m baseline. Slopes at 1 m from photoclinometry are also in the range 2-3?? after correction for image blur. Slopes exceeding the 16?? Phoenix safety limit are extremely rare. Copyright 2008 by the American Geophysical Union.

  13. A mutate-and-map strategy accurately infers the base pairs of a 35-nucleotide model RNA

    PubMed Central

    Kladwang, Wipapat; Cordero, Pablo; Das, Rhiju

    2011-01-01

    We present a rapid experimental strategy for inferring base pairs in structured RNAs via an information-rich extension of classic chemical mapping approaches. The mutate-and-map method, previously applied to a DNA/RNA helix, systematically searches for single mutations that enhance the chemical accessibility of base-pairing partners distant in sequence. To test this strategy for structured RNAs, we have carried out mutate-and-map measurements for a 35-nt hairpin, called the MedLoop RNA, embedded within an 80-nt sequence. We demonstrate the synthesis of all 105 single mutants of the MedLoop RNA sequence and present high-throughput DMS, CMCT, and SHAPE modification measurements for this library at single-nucleotide resolution. The resulting two-dimensional data reveal visually clear, punctate features corresponding to RNA base pair interactions as well as more complex features; these signals can be qualitatively rationalized by comparison to secondary structure predictions. Finally, we present an automated, sequence-blind analysis that permits the confident identification of nine of the 10 MedLoop RNA base pairs at single-nucleotide resolution, while discriminating against all 1460 false-positive base pairs. These results establish the accuracy and information content of the mutate-and-map strategy and support its feasibility for rapidly characterizing the base-pairing patterns of larger and more complex RNA systems. PMID:21239468

  14. The geography and geology of Alaska; a summary of existing knowledge, with a section on climate, and a topographic map and description thereof

    USGS Publications Warehouse

    Brooks, A.H.; Abbe, Cleveland, Jr.; Goode, R.U.

    1906-01-01

    It is the writer's purpose to describe in nontechnical language the larger geographic features and discuss their relation as far as the data available will permit. In the treatment of the geology, however, less effort will be made to make the matter acceptable to the lay reader. It is hoped, however, that a brief summary of the salient features of the geologic history' may be not without interest to the general public. If this paper serves in some measure to dispel the popular fallacies regarding Alaska and to disseminate more accurate knowledge of its geographic and geologic features, the purpose of its publication will be accomplished.

  15. Phase Space Tomography: A Simple, Portable and Accurate Technique to Map Phase Spaces of Beams with Space Charge

    SciTech Connect

    Stratakis, D.; Kishek, R. A.; Bernal, S.; Walter, M.; Haber, I.; Fiorito, R.; Thangaraj, J. C. T.; Quinn, B.; Reiser, M.; O'Shea, P. G.; Li, H.

    2006-11-27

    In order to understand the charged particle dynamics, e.g. the halo formation, emittance growth, x-y energy transfer and coupling, knowledge of the actual phase space is needed. Other the past decade there is an increasing number of articles who use tomography to map the beam phase space and measure the beam emittance. These studies where performed at high energy facilities where the effect of space charge was neglible and therefore not considered in the analysis. This work extends the tomography technique to beams with space charge. In order to simplify the analysis linear forces where assumed. By carefully modeling the tomography process using the particle-in-cell code WARP we test the validity of our assumptions and the accuracy of the reconstructed phase space. Finally, we report experimental results of phase space mapping at the University of Maryland Electron Ring (UMER) using tomography.

  16. A 125 year history of topographic mapping and GIS in the U.S. Geological Survey 1884-2009, part 2: 1980-2009

    USGS Publications Warehouse

    Usery, E. Lynn; Varanka, Dalia; Finn, Michael P.

    2009-01-01

    The United States Geological Survey (USGS) entered the mainstream of developments in computer-assisted technology for mapping during the 1970s. The introduction by USGS of digital line graphs (DLGs), digital elevation models (DEMs), and land use data analysis (LUDA) nationwide land-cover data provided a base for the rapid expansion of the use of GIS in the 1980s. Whereas USGS had developed the topologically structured DLG data and the Geographic Information Retrieval and Analysis System (GIRAS) for land-cover data, the Map Overlay Statistical System (MOSS), a nontopologically structured GIS software package developed by Autometric, Inc., under contract to the U.S. Fish and Wildlife Service, dominated the use of GIS by federal agencies in the 1970s. Thus, USGS data was used in MOSS, but the topological structure, which later became a requirement for GIS vector datasets, was not used in early GIS applications. The introduction of Esri's ARC/INFO in 1982 changed that, and by the end of the 1980s, topological structure for vector data was essential, and ARC/INFO was the dominant GIS software package used by federal agencies.

  17. Topographic attributes as a guide for automated detection or highlighting of geological features

    NASA Astrophysics Data System (ADS)

    Viseur, Sophie; Le Men, Thibaud; Guglielmi, Yves

    2015-04-01

    Photogrammetry or LIDAR technology combined with photography allow geoscientists to obtain 3D high-resolution numerical representations of outcrops, generally termed as Digital Outcrop Models (DOM). For over a decade, these 3D numerical outcrops serve as support for precise and accurate interpretations of geological features such as fracture traces or plans, strata, facies mapping, etc. These interpretations have the benefit to be directly georeferenced and embedded into the 3D space. They are then easily integrated into GIS or geomodeler softwares for modelling in 3D the subsurface geological structures. However, numerical outcrops generally represent huge data sets that are heavy to manipulate and hence to interpret. This may be particularly tedious as soon as several scales of geological features must be investigated or as geological features are very dense and imbricated. Automated tools for interpreting geological features from DOMs would be then a significant help to process these kinds of data. Such technologies are commonly used for interpreting seismic or medical data. However, it may be noticed that even if many efforts have been devoted to easily and accurately acquire 3D topographic point clouds and photos and to visualize accurate 3D textured DOMs, few attentions have been paid to the development of algorithms for automated detection of the geological structures from DOMs. The automatic detection of objects on numerical data generally assumes that signals or attributes computed from this data allows the recognition of the targeted object boundaries. The first step consists then in defining attributes that highlight the objects or their boundaries. For DOM interpretations, some authors proposed to use differential operators computed on the surface such as normal or curvatures. These methods generally extract polylines corresponding to fracture traces or bed limits. Other approaches rely on the PCA technology to segregate different topographic plans

  18. Bodily maps of emotions

    PubMed Central

    Nummenmaa, Lauri; Glerean, Enrico; Hari, Riitta; Hietanen, Jari K.

    2014-01-01

    Emotions are often felt in the body, and somatosensory feedback has been proposed to trigger conscious emotional experiences. Here we reveal maps of bodily sensations associated with different emotions using a unique topographical self-report method. In five experiments, participants (n = 701) were shown two silhouettes of bodies alongside emotional words, stories, movies, or facial expressions. They were asked to color the bodily regions whose activity they felt increasing or decreasing while viewing each stimulus. Different emotions were consistently associated with statistically separable bodily sensation maps across experiments. These maps were concordant across West European and East Asian samples. Statistical classifiers distinguished emotion-specific activation maps accurately, confirming independence of topographies across emotions. We propose that emotions are represented in the somatosensory system as culturally universal categorical somatotopic maps. Perception of these emotion-triggered bodily changes may play a key role in generating consciously felt emotions. PMID:24379370

  19. Classification of Water Surfaces Using Airborne Topographic LIDAR Data

    NASA Astrophysics Data System (ADS)

    Smeeckaert, J.; Mallet, C.; David, N.

    2013-05-01

    Accurate Digital Terrain Models (DTM) are inevitable inputs for mapping areas subject to natural hazards. Topographic airborne laser scanning has become an established technique to characterize the Earth surface: lidar provides 3D point clouds allowing a fine reconstruction of the topography. For flood hazard modeling, the key step before terrain modeling is the discrimination of land and water surfaces within the delivered point clouds. Therefore, instantaneous shoreline, river borders, inland waters can be extracted as a basis for more reliable DTM generation. This paper presents an automatic, efficient, and versatile workflow for land/water classification of airborne topographic lidar data. For that purpose, a classification framework based on Support Vector Machines (SVM) is designed. First, a restricted set of features, based only 3D lidar point coordinates and flightline information, is defined. Then, the SVM learning step is performed on small but well-targeted areas thanks to an automatic region growing strategy. Finally, label probabilities given by the SVM are merged during a probabilistic relaxation step in order to remove pixel-wise misclassification. Results show that survey of millions of points are labelled with high accuracy (>95% in most cases for coastal areas, and >89% for rivers) and that small natural and anthropic features of interest are still well classified though we work at low point densities (0.5-4 pts/m2). Our approach is valid for coasts and rivers, and provides a strong basis for further discrimination of land-cover classes and coastal habitats.

  20. Topographical atlas sheets

    USGS Publications Warehouse

    Wheeler, George Montague

    1876-01-01

    The following topographical atlas sheets, accompanying Appendix J.J. of the Annual Report of the Chief of Engineers, U.S. Army-being Annual Report upon U. S. Geographical Surveys-have been published during the fiscal year ending June 30, 1876, and are a portion of the series projected to embrace the territory of the United States lying west of the 100th meridian.

  1. Topographic and Morphologic Evidence for Flooding of Ganymede's Resurfaced Terrains by Low-Viscosity Water-Ice Lavas

    NASA Technical Reports Server (NTRS)

    McKinnon, W. B.; Schenk, P. M.; Moore, J. M.

    2001-01-01

    Topographic mapping in at least three distinct regions of Ganymede reveals that smooth terrains are flat and are topographically depressed. This and embayment relationships are consistent with volcanic resurfacing. Additional information is contained in the original extended abstract.

  2. Identification of requirements and sources for global digital topographic data

    USGS Publications Warehouse

    Gesch, Dean B.

    1993-01-01

    Many of the physical processes being studied by global change researchers are affects by land surface topography and consequently topographic data are an important requirement for these investigations. Remotely sensed data, especially those that will be collected by the instruments of the Earth Observing System, require significant correction to remove topographic effects. Although some requirements are met by existing topographic data, there are serious data shortages that will affect global change science. The interdisciplinary and multi temporal natural of global change research requires that remotely sensed data be processed using a consistent, highly accurate global topographic database so that information extracted from these data for different areas and times can be compared quantitively. Cartographic and remote sensing sources for the generation of new topographic data exist or are planned and will be helpful for fulfilling these requirements. More consistent use of accuracy statement terminology by data users and producers is necessary to better compare the requirements with existing or future data sets.

  3. Topographic slope from the SAR interferometric phase gradient

    NASA Technical Reports Server (NTRS)

    Werner, Charles L.; Rosen, Paul A.

    1993-01-01

    A new algorithm for the direct calculation of topographic slope maps from synthetic aperture radar (SAR) interferograms is presented. The algorithm derives slope maps without first requiring the creation of a digital elevational model (DEM) from the interferogram, thus obviating the need for high SNR in the interferogram and altitude calibration points for the scene. SAR data useful for interferometry has been collected by the Active Microwave Imager on board the ERS-1 satellite, when it was in a short period repeat orbit. Two passes of the radar sensor form a cross-track interferometric baseline. For a point target at some position (x,y,h), the interferometric phase difference phi is proportional to the difference in path lengths for the two sensor positions to the scatterer. Given the phase difference as measured in the complex interferogram and an accurate baseline geometry, the position of the scatterer, most significantly the height h, can be determined through triangulation. The interferometric phase measurement however is known only modulo 2-pi, and hence it is necessary to determine the correct multiple of 2-pi to add to the phase at each point to obtain an estimate of the actual phase with respect to an absolute datum. This phase unwrapping process is required for creating DEM's, and is difficult or impossible for regions of low SNR or SAR image layover. The new algorithm described here derives slope maps without requiring phase unwrapping.

  4. Topographic Structure from Motion

    NASA Astrophysics Data System (ADS)

    Fonstad, M. A.; Dietrich, J. T.; Courville, B. C.; Jensen, J.; Carbonneau, P.

    2011-12-01

    The production of high-resolution topographic datasets is of increasing concern and application throughout the geomorphic sciences, and river science is no exception. Consequently, a wide range of topographic measurement methods have evolved. Despite the range of available methods, the production of high resolution, high quality digital elevation models (DEMs) generally requires a significant investment in personnel time, hardware and/or software. However, image-based methods such as digital photogrammetry have steadily been decreasing in costs. Initially developed for the purpose of rapid, inexpensive and easy three dimensional surveys of buildings or small objects, the "structure from motion" photogrammetric approach (SfM) is a purely image based method which could deliver a step-change if transferred to river remote sensing, and requires very little training and is extremely inexpensive. Using the online SfM program Microsoft Photosynth, we have created high-resolution digital elevation models (DEM) of rivers from ordinary photographs produced from a multi-step workflow that takes advantage of free and open source software. This process reconstructs real world scenes from SfM algorithms based on the derived positions of the photographs in three-dimensional space. One of the products of the SfM process is a three-dimensional point cloud of features present in the input photographs. This point cloud can be georeferenced from a small number of ground control points collected via GPS in the field. The georeferenced point cloud can then be used to create a variety of digital elevation model products. Among several study sites, we examine the applicability of SfM in the Pedernales River in Texas (USA), where several hundred images taken from a hand-held helikite are used to produce DEMs of the fluvial topographic environment. This test shows that SfM and low-altitude platforms can produce point clouds with point densities considerably better than airborne LiDAR, with

  5. Ontology patterns for complex topographic feature yypes

    USGS Publications Warehouse

    Varanka, Dalia E.

    2011-01-01

    Complex feature types are defined as integrated relations between basic features for a shared meaning or concept. The shared semantic concept is difficult to define in commonly used geographic information systems (GIS) and remote sensing technologies. The role of spatial relations between complex feature parts was recognized in early GIS literature, but had limited representation in the feature or coverage data models of GIS. Spatial relations are more explicitly specified in semantic technology. In this paper, semantics for topographic feature ontology design patterns (ODP) are developed as data models for the representation of complex features. In the context of topographic processes, component assemblages are supported by resource systems and are found on local landscapes. The topographic ontology is organized across six thematic modules that can account for basic feature types, resource systems, and landscape types. Types of complex feature attributes include location, generative processes and physical description. Node/edge networks model standard spatial relations and relations specific to topographic science to represent complex features. To demonstrate these concepts, data from The National Map of the U. S. Geological Survey was converted and assembled into ODP.

  6. Oil Exploration Mapping

    NASA Technical Reports Server (NTRS)

    1994-01-01

    After concluding an oil exploration agreement with the Republic of Yemen, Chevron International needed detailed geologic and topographic maps of the area. Chevron's remote sensing team used imagery from Landsat and SPOT, combining images into composite views. The project was successfully concluded and resulted in greatly improved base maps and unique topographic maps.

  7. How to perform RT-qPCR accurately in plant species? A case study on flower colour gene expression in an azalea (Rhododendron simsii hybrids) mapping population

    PubMed Central

    2013-01-01

    Background Flower colour variation is one of the most crucial selection criteria in the breeding of a flowering pot plant, as is also the case for azalea (Rhododendron simsii hybrids). Flavonoid biosynthesis was studied intensively in several species. In azalea, flower colour can be described by means of a 3-gene model. However, this model does not clarify pink-coloration. The last decade gene expression studies have been implemented widely for studying flower colour. However, the methods used were often only semi-quantitative or quantification was not done according to the MIQE-guidelines. We aimed to develop an accurate protocol for RT-qPCR and to validate the protocol to study flower colour in an azalea mapping population. Results An accurate RT-qPCR protocol had to be established. RNA quality was evaluated in a combined approach by means of different techniques e.g. SPUD-assay and Experion-analysis. We demonstrated the importance of testing noRT-samples for all genes under study to detect contaminating DNA. In spite of the limited sequence information available, we prepared a set of 11 reference genes which was validated in flower petals; a combination of three reference genes was most optimal. Finally we also used plasmids for the construction of standard curves. This allowed us to calculate gene-specific PCR efficiencies for every gene to assure an accurate quantification. The validity of the protocol was demonstrated by means of the study of six genes of the flavonoid biosynthesis pathway. No correlations were found between flower colour and the individual expression profiles. However, the combination of early pathway genes (CHS, F3H, F3'H and FLS) is clearly related to co-pigmentation with flavonols. The late pathway genes DFR and ANS are to a minor extent involved in differentiating between coloured and white flowers. Concerning pink coloration, we could demonstrate that the lower intensity in this type of flowers is correlated to the expression of F3'H

  8. Topographic Mapping of Residual Vision by Computer

    ERIC Educational Resources Information Center

    MacKeben, Manfred

    2008-01-01

    Many persons with low vision have diseases that damage the retina only in selected areas, which can lead to scotomas (blind spots) in perception. The most frequent of these diseases is age-related macular degeneration (AMD), in which foveal vision is often impaired by a central scotoma that impairs vision of fine detail and causes problems with…

  9. Predicting Potential Evaporation in Topographically Complex Terrain

    NASA Astrophysics Data System (ADS)

    Koohafkan, M.; Thompson, S. E.; Hamilton, M. P.

    2012-12-01

    Predicting and understanding the water cycle in topographically complex terrain poses challenges for upscaling point-scale measurements of water and energy balance and for downscaling observations made from remote sensing or predictions made via global circulation models. This study evaluates hydrologic and climate data drawn from a spatially-distributed wireless sensor network at the Blue Oak Ranch Reserve near San Jose, California to investigate the influence of topographic variation, landscape position, and local ecology (vegetation) on one core component of the water balance: potential evaporation. High-resolution observations of solar radiation, ambient temperature, wind speed, and relative humidity are combined with canopy maps generated from LiDAR flyovers to develop spatially-distributed predictions of potential evaporation. These data are compared to estimates of EP based on inverse modeling of surface soil moisture data. Preliminary results suggest that the spatial structure of microclimate at Blue Oak Ranch Reserve is dominated by variations around the elevation gradient, with strong nocturnal inversions hypothesized to reflect the influence of the coastal marine layer. Estimates of EP based on the Penman-Monteith equation suggest that EP could vary by up to a factor of 5 across the site, with differences in vapor pressure deficit and canopy height largely responsible for this variability. The results suggest that a) large differences in the timing and magnitude of water stress could arise in topographically complex terrain due to localized differences in energy balance, and b) both localized and regional effects need to be accounted for when downscaling climate data over topographically complex sites. 2) Color map showing preliminary estimates of annual EP incorporating canopy information (spatially-distributed values of aerodynamic resistance and LAI) drawn from LiDAR imagery. The effect of the resistance on the dynamics is striking in its ability to

  10. Deriving the optimal scale for relating topographic attributes and cover crop plant biomass

    NASA Astrophysics Data System (ADS)

    Muñoz, Juan D.; Kravchenko, Alexandra

    2012-12-01

    The use of cover crops generates a number of agro-ecological benefits for sustainable row-crop agriculture. However, their performance across agricultural fields is often highly spatially variable and there is insufficient information on factors affecting this variability and on tools to manage it. Topography is one of the main factors affecting spatial patterns of plant growth in the American Midwest. Digital elevation models are readily available for deriving topographic attributes; also sensor digital data can be used to indirectly assess cover crop biomass. However, processing procedures for identifying the proper scale of topographic and biomass representations are not well defined. The objectives of this study are to examine how relationships between cover crop biomass, assessed using the normalized difference vegetation index (NDVI), and topography depend on the neighborhood size used for deriving topographic attributes and creating NDVI maps; and identify the optimal neighborhood size for correlation and regression analyses. Slope, relative elevation and the potential solar radiation index were the variables that contributed the most to explaining variability in NDVI for raw data. However, other topographic attributes became significant predictors of NDVI at larger neighborhood sizes. We demonstrated that neighborhood size greatly affects some topographic attributes, i.e. curvature, flow accumulation, flow length and the wetness index; and changing the neighborhood size in both topography and NDVI considerably changes the strength of the prediction performance in multiple regression models. We studied six neighborhood sizes from 1 to 40 m and the original raw data. On average, across all studied fields the best performance of multiple regression, as determined by the adjusted-R2, was obtained at neighborhood sizes 20 and 40 m. Parameters of semivariogram models for terrain slope, such as the spatial autocorrelation range and the nugget/sill ratio, were

  11. Advancing Glaciological Applications of Remote Sensing with EO-1: (1) Mapping Snow Grain Size and Albedo on the Greenland Ice Sheet Using an Imaging Spectrometer, and (2) ALI Evaluation for Subtle Surface Topographic Mapping via Shape-from Shading

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Hyperion sensor, onboard NASA's Earth Observing-1 (EO-1) satellite,is an imaging spectroradiometer with 220 spectral bands over the spectral range from 0.4 - 2.5 microns. Over the course of summer 2001, the instrument acquired numerous images over the Greenland ice sheet. Our main motivation is to develop an accurate and robust approach for measuring the broadband albedo of snow from satellites. Satellite-derived estimates of broadband have typically been plagued with three problems: errors resulting from inaccurate atmospheric correction, particularly in the visible wavelengths from the conversion of reflectance to albedo (accounting for snow BRDE); and errors resulting from regression-based approaches used to convert narrowband albedo to broadband albedo. A typerspectral method has been developed that substantially reduces these three main sources of error and produces highly accurate estimates of snow albedo. This technique uses hyperspectral data from 0.98 - 1.06 microns, spanning a spectral absorption feature centered at 1.03 microns. A key aspect of this work is that this spectral range is within an atmospheric transmission window and reflectances are largely unaffected by atmospheric aerosols, water vapor, or ozone. In this investigation, we make broadband albedo measurements at four sites on the Greenland ice sheet: Summit, a high altitude station in central Greenland; the ETH/CU camp, a camp on the equilibrium line in western Greenland; Crawford Point, a site located between Summit and the ETH/CU camp; and Tunu, a site located in northeastern Greenland at 2000 m. altitude. Each of these sites has an automated weather station (AWS) that continually measures broadband albedo thereby providing validation data.

  12. On the utility of spectroscopic imaging as a tool for generating geometrically accurate MR images and parameter maps in the presence of field inhomogeneities and chemical shift effects.

    PubMed

    Bakker, Chris J G; de Leeuw, Hendrik; van de Maat, Gerrit H; van Gorp, Jetse S; Bouwman, Job G; Seevinck, Peter R

    2013-01-01

    Lack of spatial accuracy is a recognized problem in magnetic resonance imaging (MRI) which severely detracts from its value as a stand-alone modality for applications that put high demands on geometric fidelity, such as radiotherapy treatment planning and stereotactic neurosurgery. In this paper, we illustrate the potential and discuss the limitations of spectroscopic imaging as a tool for generating purely phase-encoded MR images and parameter maps that preserve the geometry of an object and allow localization of object features in world coordinates. Experiments were done on a clinical system with standard facilities for imaging and spectroscopy. Images were acquired with a regular spin echo sequence and a corresponding spectroscopic imaging sequence. In the latter, successive samples of the acquired echo were used for the reconstruction of a series of evenly spaced images in the time and frequency domain. Experiments were done with a spatial linearity phantom and a series of test objects representing a wide range of susceptibility- and chemical-shift-induced off-resonance conditions. In contrast to regular spin echo imaging, spectroscopic imaging was shown to be immune to off-resonance effects, such as those caused by field inhomogeneity, susceptibility, chemical shift, f(0) offset and field drift, and to yield geometrically accurate images and parameter maps that allowed object structures to be localized in world coordinates. From these illustrative examples and a discussion of the limitations of purely phase-encoded imaging techniques, it is concluded that spectroscopic imaging offers a fundamental solution to the geometric deficiencies of MRI which may evolve toward a practical solution when full advantage will be taken of current developments with regard to scan time reduction. This perspective is backed up by a demonstration of the significant scan time reduction that may be achieved by the use of compressed sensing for a simple phantom. PMID:22898694

  13. Cornea Optical Topographical Scan System (COTSS)

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The Cornea Optical Topographical Scan System (COTSS) is an instrument designed for use by opthalmologist to aid in performing surgical procedures such as radial keratotomy and to provide quick accurate data to aid in prescribing contact lenses and eyeglasses. A breadboard of the system was built and demonstrated in June of 1984. Additional refinements to the breadboard are needed to meet systems requirements prior to proceeding with prototype development. The present status of the COTSS instrument is given and the areas in which system refinements are required, are defined.

  14. Accurate and Fully Automatic Hippocampus Segmentation Using Subject-Specific 3D Optimal Local Maps Into a Hybrid Active Contour Model

    PubMed Central

    Gkontra, Polyxeni; Daras, Petros; Maglaveras, Nicos

    2014-01-01

    Assessing the structural integrity of the hippocampus (HC) is an essential step toward prevention, diagnosis, and follow-up of various brain disorders due to the implication of the structural changes of the HC in those disorders. In this respect, the development of automatic segmentation methods that can accurately, reliably, and reproducibly segment the HC has attracted considerable attention over the past decades. This paper presents an innovative 3-D fully automatic method to be used on top of the multiatlas concept for the HC segmentation. The method is based on a subject-specific set of 3-D optimal local maps (OLMs) that locally control the influence of each energy term of a hybrid active contour model (ACM). The complete set of the OLMs for a set of training images is defined simultaneously via an optimization scheme. At the same time, the optimal ACM parameters are also calculated. Therefore, heuristic parameter fine-tuning is not required. Training OLMs are subsequently combined, by applying an extended multiatlas concept, to produce the OLMs that are anatomically more suitable to the test image. The proposed algorithm was tested on three different and publicly available data sets. Its accuracy was compared with that of state-of-the-art methods demonstrating the efficacy and robustness of the proposed method. PMID:27170866

  15. Accurate and Fully Automatic Hippocampus Segmentation Using Subject-Specific 3D Optimal Local Maps Into a Hybrid Active Contour Model.

    PubMed

    Zarpalas, Dimitrios; Gkontra, Polyxeni; Daras, Petros; Maglaveras, Nicos

    2014-01-01

    Assessing the structural integrity of the hippocampus (HC) is an essential step toward prevention, diagnosis, and follow-up of various brain disorders due to the implication of the structural changes of the HC in those disorders. In this respect, the development of automatic segmentation methods that can accurately, reliably, and reproducibly segment the HC has attracted considerable attention over the past decades. This paper presents an innovative 3-D fully automatic method to be used on top of the multiatlas concept for the HC segmentation. The method is based on a subject-specific set of 3-D optimal local maps (OLMs) that locally control the influence of each energy term of a hybrid active contour model (ACM). The complete set of the OLMs for a set of training images is defined simultaneously via an optimization scheme. At the same time, the optimal ACM parameters are also calculated. Therefore, heuristic parameter fine-tuning is not required. Training OLMs are subsequently combined, by applying an extended multiatlas concept, to produce the OLMs that are anatomically more suitable to the test image. The proposed algorithm was tested on three different and publicly available data sets. Its accuracy was compared with that of state-of-the-art methods demonstrating the efficacy and robustness of the proposed method. PMID:27170866

  16. Topographical scanning and reproduction of near-planar surfaces of paintings

    NASA Astrophysics Data System (ADS)

    Elkhuizen, Willemijn S.; Zaman, Tim; Verhofstad, Wim; Jonker, Pieter P.; Dik, Joris; Geraedts, Jo M. P.

    2014-02-01

    Paintings are near-planar objects with material characteristics that vary widely. The fact that paint has a material presence is often overlooked, mostly because we often encounter these artworks in the form of two-dimensional reproductions. Capturing paintings in the third dimension is not only important for study, restoration and conservation, but it also inspires 3D printing methods1, particularly through the high demands it makes on reproducing color, gloss and texture. "A hybrid solution between fringe projection and stereo imaging is proposed as 3D imaging method, with a setup involving two cameras and a projector. Fringe projection is aided by sparse stereo matching to serve as image encoder. These encoded images processed by the stereo cameras solve the correspondence problem in stereo matching, leading to a dense and accurate topographical map, while simultaneously capturing the composition of the painting in full color"1. The topographical map and color data are used to make hardcopy 3D reproductions, using a specially developed printing system. Several paintings by Dutch masters Rembrandt and Van Gogh have been scanned and reproduced using this technique. These 3D printed reproductions have been evaluated by experts, both individually and in a side-by-side comparison with the original.

  17. Objective extraction of channel heads from high-resolution topographic data

    NASA Astrophysics Data System (ADS)

    Clubb, Fiona J.; Mudd, Simon M.; Milodowski, David T.; Hurst, Martin D.; Slater, Louise J.

    2014-05-01

    Fluvial landscapes are dissected by channels, and at their upstream termini are channel heads. Accurate reconstruction of the fluvial domain is fundamental to understanding runoff generation, storm hydrology, sediment transport, biogeochemical cycling, and landscape evolution. Many methods have been proposed for predicting channel head locations using topographic data, yet none have been tested against a robust field data set of mapped channel heads across multiple landscapes. In this study, four methods of channel head prediction were tested against field data from four sites with high-resolution DEMs: slope-area scaling relationships; two techniques based on landscape tangential curvature; and a new method presented here, which identifies the change from channel to hillslope topography along a profile using a transformed longitudinal coordinate system. Our method requires only two user-defined parameters, determined via independent statistical analysis. Slope-area plots are traditionally used to identify the fluvial-hillslope transition, but we observe no clear relationship between this transition and field-mapped channel heads. Of the four methods assessed, one of the tangential curvature methods and our new method most accurately reproduce the measured channel heads in all four field sites (Feather River CA, Mid Bailey Run OH, Indian Creek OH, Piedmont VA), with mean errors of -11, -7, 5, and -24 m and 34, 3, 12, and -58 m, respectively. Negative values indicate channel heads located upslope of those mapped in the field. Importantly, these two independent methods produce mutually consistent estimates, providing two tests of channel head locations based on independent topographic signatures.

  18. Topographic Data Derived from Scans of the Original Apollo Panoramic Flight Film

    NASA Astrophysics Data System (ADS)

    Rosiek, M. R.; Lawrence, S. J.; Robinson, M. S.; Close, W.; Grunsfeld, J.; Ingram, R.; Jefferson, L.; Locke, S.; Mitchell, R.; Scarsella, T.; White, M.; Archinal, B. A.; Hare, T.; Redding, B. L.; Galuszka, D. M.; Hopkins, M.

    2010-03-01

    JSC and ASU are creating a digital archive of the Apollo flight films. Panoramic stereo models are useful for topographic mapping. Image resolution varies from 1-2 m/pixel. Expected vertical accuracy of the topographic data is 0.5-1.5 m.

  19. Using a Sonified Topographic Approach to Communicate Spatial Information to People with Visual Impairments

    ERIC Educational Resources Information Center

    Thebpanya, Paporn

    2010-01-01

    This study implemented tactile interfaces with audio representations to convey spatial information on topographic maps. Two sound variables, pitch and duration, were incorporated with contour lines to represent various aspects of topographic features such as elevation, slope, profile, and landform. The effect of one sound variable (pitch) vs. a…

  20. Mapping.

    ERIC Educational Resources Information Center

    Kinney, Douglas M.; McIntosh, Willard L.

    1979-01-01

    The area of geological mapping in the United States in 1978 increased greatly over that reported in 1977; state geological maps were added for California, Idaho, Nevada, and Alaska last year. (Author/BB)

  1. 47 CFR 73.312 - Topographic data.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Topographic data. 73.312 Section 73.312... Broadcast Stations § 73.312 Topographic data. (a) In the preparation of the profile graphs previously... question, the next best topographic information should be used. Topographic data may sometimes be...

  2. 47 CFR 73.312 - Topographic data.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Topographic data. 73.312 Section 73.312... Broadcast Stations § 73.312 Topographic data. (a) In the preparation of the profile graphs previously... question, the next best topographic information should be used. Topographic data may sometimes be...

  3. 47 CFR 73.312 - Topographic data.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Topographic data. 73.312 Section 73.312... Broadcast Stations § 73.312 Topographic data. (a) In the preparation of the profile graphs previously... question, the next best topographic information should be used. Topographic data may sometimes be...

  4. 47 CFR 73.312 - Topographic data.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Topographic data. 73.312 Section 73.312... Broadcast Stations § 73.312 Topographic data. (a) In the preparation of the profile graphs previously... question, the next best topographic information should be used. Topographic data may sometimes be...

  5. 47 CFR 73.312 - Topographic data.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Topographic data. 73.312 Section 73.312... Broadcast Stations § 73.312 Topographic data. (a) In the preparation of the profile graphs previously... question, the next best topographic information should be used. Topographic data may sometimes be...

  6. Scaling characteristics of topographic depressions

    NASA Astrophysics Data System (ADS)

    Le, P. V.; Kumar, P.

    2013-12-01

    Topographic depressions, areas of no lateral surface flow, are ubiquitous characteristic of land surface that control many ecosystem and biogeochemical processes. Landscapes with high density of depressions increase the surface storage capacity, whereas lower depression density increase runoff, thus influencing soil moisture states, hydrologic connectivity and the climate--soil--vegetation interactions. With the widespread availability of high resolution LiDAR based digital elevation model (lDEM) data, it is now possible to identify and characterize the structure of the spatial distribution of topographic depressions for incorporation in ecohydrologic and biogeochemical studies. Here we use lDEM data to document the prevalence and patterns of topographic depressions across five different landscapes in the United States and quantitatively characterize the distribution of attributes, such as surface area, storage volume, and the distance to the nearest neighbor. Through the use of a depression identification algorithm, we show that these distribution attributes follow scaling laws indicative of a fractal structure in which a large fraction of land surface areas can consist of high number of topographic depressions, accounting for 4 to 200 mm of depression storage. This implies that the impacts of small-scale topographic depressions in the fractal landscapes on the redistribution of surface energy fluxes, evaporation, and hydrologic connectivity are quite significant.

  7. Topographical Risk Assessment

    2002-09-24

    TRA was developed as a computer tool for the DOE Office of River Protection (ORP) that will provides the capability to visualize and rapidly understand information about the risks associated with the River protection Project (RPP). Previously, technical and programmatic risk management within ORP had relied heavily on risk lists and other techniques that presented risk information but did not place it in perspective of the overall project. This made it difficult for ORP seniormore » management to understand the risk information presented, prioritize their activities, and provide direction to ORP staff and contractors about how to manage specific risk events. The TRA visualization tool, provides the appropriate context and perspective that allows senior management to effectively manage risks. Basically, the TRA overlays information about risks associated with specific activities and their magnitudes on top of the project baseline schedule. this provides senior management with information about the magnitudes of specific risk events as well as their timing, and allows them to focus their attention and resources on the risks that merit attention and possible further action. The TRA tool can also be used to display other types of information associated with scheduled activities, such as cost to date, technical performance, schedule performance, etc. Additionally, the base of the 3-dimensional representation can be changed to other types of graphics, such as maps, process flow diagrams, etc., which allows the display of other types of informatio, such as hazards, health and safety risks, and system availability.« less

  8. Volunteer map data collection at the USGS

    USGS Publications Warehouse

    Eric, B. Wolf; Poore, Barbara S.; Caro, Holly K.; Matthews, Greg D.

    2011-01-01

    Since 1994, citizen volunteers have helped the U.S. Geological Survey (USGS) improve its topographic maps. Through the Earth Science Corps program, citizens were able to "adopt a quad" and collect new information and update existing map features. Until its conclusion in 2001, as many as 300 volunteers annotated paper maps which were incorporated into the USGS topographic-map revision process.

  9. Topographical analysis of lunar impact craters using SELENE images

    NASA Astrophysics Data System (ADS)

    Vijayan, S.; Vani, K.; Sanjeevi, S.

    2013-10-01

    Lunar craters provide ample opportunities to study and understand crater morphology because of their vast numbers. This paper focuses on the topographical mapping of 33 Mare craters (Flat- and Round-floor) of ˜2 km diameter, using the SELENE DTM. Each crater was analyzed individually for its slope, regional topography and rim signature. The crater slope analysis revealed a small slope variation between the flat- and round-floor craters, in a similar diameter range, with some overlap between them. In the regional topographical analysis, the impact craters formed on the flat- and sloped-surface were analyzed in detail. The crater profile extracted through the rim crest was compared with its corresponding regional topographic profile (obtained over ˜3 crater radii). Four types of crater occurrences were observed: type i, ii and iv craters were formed on sloped surface, whereas type iii craters are formed on a flat surface with an equally raised rim. The occurrences of the rim crest on type i and ii craters are on the topographically elevated side of the terrain. But in type iv craters, the rim crest occurs on the topographically lower side of the terrain. The type iv craters uplifted the topographically lower terrain, which depicts the alteration that had taken place due to the impact. This topographical analysis suggests that the surrounding topography should also be considered for understanding the craters. Finally, from the crater rim signature analysis, it was evident that the prominent V-shaped incisions on the rim are caused due to landslide/slumping and by small impactors. This DTM based simple lunar crater analysis revealed information about the crater association with their surrounding topography and their morphological variations on flat- and sloped- surface.

  10. Terrestrial Ecosystems - Topographic Moisture Potential of the Conterminous United States

    USGS Publications Warehouse

    Cress, Jill J.; Sayre, Roger G.; Comer, Patrick; Warner, Harumi

    2009-01-01

    As part of an effort to map terrestrial ecosystems, the U.S. Geological Survey has generated topographic moisture potential classes to be used in creating maps depicting standardized, terrestrial ecosystem models for the conterminous United States, using an ecosystems classification developed by NatureServe. A biophysical stratification approach, developed for South America and now being implemented globally, was used to model the ecosystem distributions. Substrate moisture regimes strongly influence the differentiation and distribution of terrestrial ecosystems, and therefore topographic moisture potential is one of the key input layers in this biophysical stratification. The method used to produce these topographic moisture potential classes was based on the derivation of ground moisture potential using a combination of computed topographic characteristics (CTI, slope, and aspect) and mapped National Wetland Inventory (NWI) boundaries. This method does not use climate or soil attributes to calculate relative topographic moisture potential since these characteristics are incorporated into the ecosystem model though other input layers. All of the topographic data used for this assessment were derived from the USGS 30-meter National Elevation Dataset (NED ) including the National Compound Topographic Index (CTI). The CTI index is a topographically derived measure of slope for a raster cell and the contributing area from upstream raster cells, and thus expresses potential for water flow to a point. In other words CTI data are 'a quantification of the position of a site in the local landscape', where the lowest values indicate ridges and the highest values indicate stream channels, lakes and ponds. These CTI values were compared to independent estimates of water accumulation by obtaining geospatial data from a number of sample locations representing two types of NWI boundaries: freshwater emergent wetlands and freshwater forested/shrub wetlands. Where these shorelines

  11. The Importance of Measurement Errors for Deriving Accurate Reference Leaf Area Index Maps for Validation of Moderate-Resolution Satellite LAI Products

    NASA Technical Reports Server (NTRS)

    Huang, Dong; Yang, Wenze; Tan, Bin; Rautiainen, Miina; Zhang, Ping; Hu, Jiannan; Shabanov, Nikolay V.; Linder, Sune; Knyazikhin, Yuri; Myneni, Ranga B.

    2006-01-01

    The validation of moderate-resolution satellite leaf area index (LAI) products such as those operationally generated from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor data requires reference LAI maps developed from field LAI measurements and fine-resolution satellite data. Errors in field measurements and satellite data determine the accuracy of the reference LAI maps. This paper describes a method by which reference maps of known accuracy can be generated with knowledge of errors in fine-resolution satellite data. The method is demonstrated with data from an international field campaign in a boreal coniferous forest in northern Sweden, and Enhanced Thematic Mapper Plus images. The reference LAI map thus generated is used to assess modifications to the MODIS LAI/fPAR algorithm recently implemented to derive the next generation of the MODIS LAI/fPAR product for this important biome type.

  12. Intercomparison and suitability of five Greenland topographic datasets for the purpose of hydrologic runoff modeling

    NASA Astrophysics Data System (ADS)

    Pitcher, L. H.; Smith, L. C.; Rennermalm, A. K.; Chu, V. W.; Gleason, C. J.; Yang, K.; Finnegan, D. C.; LeWinter, A. L.; Moller, D.; Moustafa, S.

    2012-12-01

    Rapid melting of the Greenland Ice Sheet (GrIS) and subsequent sea level rise has underscored the need for accurate modeling of hydrologic processes. Researchers rely on the accuracy of topography datasets for this purpose, especially in remote areas like Greenland where in situ validation data are difficult to acquire. A number of new remotely-sensed Digital Elevation Models (DEMs) have recently become available for Greenland, but a comparative study of their respective quality and suitability for hydrologic modeling has not been undertaken. We examine five such remotely-sensed DEMs acquired for proglacial and supraglacial ablation zones of Greenland, namely (1) WorldView stereo DEMs, (2) NASA GLISTIN-A experimental radar, (3) NASA/IceBridge Airborne Topographic Mapper (ATM), (4) Greenland Ice Mapping Project (GIMP) DEM, and (5) ASTER DEM. The quality, strengths and weaknesses of these DEMs for GrIS hydrologic modeling is assessed through intercomparison and in situ terrestrial lidar scanning data with precise RTK GPS control. Additionally, gridded bedrock (i.e. NASA/IceBridge Multichannel Coherent Radar Depth Sounder (MCoRDS); Bamber DEMs) and surface topography datasets are combined to create a hydraulic potentiometric surface for hydrologic modeling. Finally, the suitability of these combined topographic products for hydrologic modeling, characterization of GrIS meltwater runoff, and estimating sub- and/or englacial pathways is explored.

  13. Regional Topographic Views of Mars from MOLA

    NASA Technical Reports Server (NTRS)

    2000-01-01

    With one year of global mapping of the Mars Global Surveyor mission completed, the MOLA dataset has achieved excellent spatial and vertical resolution. The maps below (and above) have been produced from the altimetric observations collected during MOLA's first year of global mapping and provide a variety of regional topographic views of the Martian surface. The maps were compiled from a data base of 266.7 million laser altimetric measurements collected between March 1, 1999 and February 29, 2000. In each map the spatial resolution is approximately 1/16o by 1/32o (where 1o on Mars is about 59 km) and the vertical accuracy is approximately 1 meter. Note that the sizes of the regions vary. Click on image for to see full resolution (Warning! these are large files) [figure removed for brevity, see original site] Nirgal Vallis region: 23o to 33o S; 313 to 323o E.

    [figure removed for brevity, see original site] Locras Valles region: 5o to 15o N; 45 to 55o E.

    [figure removed for brevity, see original site] Syrtis Major: 5o to 15o S; 62 to 72o E.

    [figure removed for brevity, see original site] Viking 1 landing site: 20o to 25o N; 310 to 315o E. The landing site is marked by the plus sign.

    [figure removed for brevity, see original site] Nicholson crater: 5o S to 5o N; 190 to 200o E. [figure removed for brevity, see original site] Schiaparelli crater: 8o S to 2o N; 12 to 22o E.

  14. Topographical pathways guide chemical microswimmers.

    PubMed

    Simmchen, Juliane; Katuri, Jaideep; Uspal, William E; Popescu, Mihail N; Tasinkevych, Mykola; Sánchez, Samuel

    2016-01-01

    Achieving control over the directionality of active colloids is essential for their use in practical applications such as cargo carriers in microfluidic devices. So far, guidance of spherical Janus colloids was mainly realized using specially engineered magnetic multilayer coatings combined with external magnetic fields. Here we demonstrate that step-like submicrometre topographical features can be used as reliable docking and guiding platforms for chemically active spherical Janus colloids. For various topographic features (stripes, squares or circular posts), docking of the colloid at the feature edge is robust and reliable. Furthermore, the colloids move along the edges for significantly long times, which systematically increase with fuel concentration. The observed phenomenology is qualitatively captured by a simple continuum model of self-diffusiophoresis near confining boundaries, indicating that the chemical activity and associated hydrodynamic interactions with the nearby topography are the main physical ingredients behind the observed behaviour. PMID:26856370

  15. Topographical pathways guide chemical microswimmers

    PubMed Central

    Simmchen, Juliane; Katuri, Jaideep; Uspal, William E.; Popescu, Mihail N.; Tasinkevych, Mykola; Sánchez, Samuel

    2016-01-01

    Achieving control over the directionality of active colloids is essential for their use in practical applications such as cargo carriers in microfluidic devices. So far, guidance of spherical Janus colloids was mainly realized using specially engineered magnetic multilayer coatings combined with external magnetic fields. Here we demonstrate that step-like submicrometre topographical features can be used as reliable docking and guiding platforms for chemically active spherical Janus colloids. For various topographic features (stripes, squares or circular posts), docking of the colloid at the feature edge is robust and reliable. Furthermore, the colloids move along the edges for significantly long times, which systematically increase with fuel concentration. The observed phenomenology is qualitatively captured by a simple continuum model of self-diffusiophoresis near confining boundaries, indicating that the chemical activity and associated hydrodynamic interactions with the nearby topography are the main physical ingredients behind the observed behaviour. PMID:26856370

  16. Complex Topographic Feature Ontology Patterns

    USGS Publications Warehouse

    Varanka, Dalia E.; Jerris, Thomas J.

    2015-01-01

    Semantic ontologies are examined as effective data models for the representation of complex topographic feature types. Complex feature types are viewed as integrated relations between basic features for a basic purpose. In the context of topographic science, such component assemblages are supported by resource systems and found on the local landscape. Ontologies are organized within six thematic modules of a domain ontology called Topography that includes within its sphere basic feature types, resource systems, and landscape types. Context is constructed not only as a spatial and temporal setting, but a setting also based on environmental processes. Types of spatial relations that exist between components include location, generative processes, and description. An example is offered in a complex feature type ‘mine.’ The identification and extraction of complex feature types are an area for future research.

  17. 47 CFR 80.757 - Topographical data.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Topographical data. 80.757 Section 80.757... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.757 Topographical data. (a... elevations from a 30 second point or better topographic data file such as those available for the...

  18. 47 CFR 80.757 - Topographical data.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Topographical data. 80.757 Section 80.757... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.757 Topographical data. (a... elevations from a 30 second point or better topographic data file such as those available for the...

  19. 47 CFR 80.757 - Topographical data.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Topographical data. 80.757 Section 80.757... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.757 Topographical data. (a... elevations from a 30 second point or better topographic data file such as those available for the...

  20. 47 CFR 80.757 - Topographical data.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Topographical data. 80.757 Section 80.757... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.757 Topographical data. (a... elevations from a 30 second point or better topographic data file such as those available for the...

  1. 47 CFR 80.757 - Topographical data.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Topographical data. 80.757 Section 80.757... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.757 Topographical data. (a... elevations from a 30 second point or better topographic data file such as those available for the...

  2. Topographic characterization of glazed surfaces

    NASA Astrophysics Data System (ADS)

    Fröberg, Linda; Hupa, Leena

    2008-01-01

    Detailed characterization of surface microstructure, i.e. phase composition and surface geometry, has become an important criterion of glazed ceramics. Topographic characterization is an important parameter in, e.g. estimating the influence of additional films on the average roughness of a surface. Also, the microscaled and nanoscaled roughnesses correlate with the cleanability and the self-cleaning properties of the surfaces. In this work the surface geometry of several matte glazes were described by topography and roughness as given by whitelight confocal microscopy and atomic force microscopy. Different measuring parameters were compared to justify the usefulness of the techniques in giving a comprehensive description of the surface microstructure. The results suggest that confocal microscopy is well suited for giving reliable topographical parameters for matte surfaces with microscaled crystals in the surfaces. Atomic force microscopy was better suited for smooth surfaces or for describing the local topographic parameters of closely limited areas, e.g. the surroundings of separate crystals in the surface.

  3. Towards a definition of topographic divisions for Italy

    NASA Astrophysics Data System (ADS)

    Guzzetti, Fausto; Reichenbach, Paola

    1994-11-01

    The study has divided Italy into eight major topographic divisions (provinces) and 30 minor divisions (sections) that are similar to N. Fenneman's units of the United States. Provinces and sections are generally consistent with observed morphology. The new units were defined step-wise in a semi-quantitative approach that combined an unsupervised three-class cluster analysis of four derivatives of altitude, visual interpretation of morphometric maps (including shaded relief), and comparative inspection of small-scale geological and structural maps. The four variables are altitude, slope curvature, frequency of slope reversal, and elevation-relief ratio. Highland, upland, and lowland topographic types were identified. The variables were computed from a 230 m resolution digital terrain model, regridded from the original 230 m DEM obtained by mosaicking the entire Italian mean elevation archive.

  4. Infrasound and the avian navigational map

    USGS Publications Warehouse

    Hagstrum, J.T.

    2001-01-01

    Birds can accurately navigate over hundreds to thousands of kilometres, and use celestial and magnetic compass senses to orient their flight. How birds determine their location in order to select the correct homeward bearing (map sense) remains controversial, and has been attributed to their olfactory or magnetic senses. Pigeons can hear infrasound down to 0??05 Hz, and an acoustic avian map is proposed consisting of infrasonic cues radiated from steep-sided topographic features. The source of these infrasonic signals is microseisms continuously generated by interfering oceanic waves. Atmospheric processes affecting the infrasonic map cues can explain perplexing experimental results from pigeon releases. Moreover, four recent disrupted pigeon races in Europe and the north-eastern USA intersected infrasonic shock waves from the Concorde supersonic transport. Having an acoustic map might also allow clock-shifted birds to test their homeward progress and select between their magnetic and solar compasses.

  5. Topographic change detection at select archeological sites in Grand Canyon National Park, Arizona, 2007–2010

    USGS Publications Warehouse

    Collins, Brian D.; Corbett, Skye C.; Fairley, Helen C.; Minasian, Diane L.; Kayen, Robert; Dealy, Timothy P.; Bedford, David R.

    2012-01-01

    Human occupation in Grand Canyon, Arizona, dates from at least 11,000 years before present to the modern era. For most of this period, the only evidence of human occupation in this iconic landscape is provided by archeological sites. Because of the dynamic nature of this environment, many archeological sites are subject to relatively rapid topographic change. Quantifying the extent, magnitude, and cause of such change is important for monitoring and managing these archeological sites. Such quantification is necessary to help inform the continuing debate on whether and how controlled releases from Glen Canyon Dam, located immediately upstream of Grand Canyon National Park, are affecting site erosion rates, artifact transport, and archeological resource preservation along the Colorado River in Grand Canyon. Although long-term topographic change resulting from a variety of natural processes is inherent in the Grand Canyon region, continued erosion of archeological sites threatens both the archeological resources and our future ability to study evidence of past cultural habitation. Thus, this subject is of considerable interest to National Park Service managers and other stakeholders in the Glen Canyon Dam Adaptive Management Program. Understanding the causes and effects of archeological site erosion requires a knowledge of several factors, including the location, timing, and magnitude of the changes occurring in relation to archeological resources, the rates of change, and the relative contribution of potential causes. These potential causes include sediment depletion associated with managed flows from Glen Canyon Dam, site-specific weather and overland flow patterns, visitor impacts, and long-term regional climate change. To obtain this information, highly accurate, spatially specific data are needed from sites undergoing change. Using terrestrial lidar techniques, and building upon three previous surveys of archeological sites performed in 2006 and 2007, we

  6. Digital floodplain mapping and an analysis of errors involved

    USGS Publications Warehouse

    Hamblen, C.S.; Soong, D.T.; Cai, X.

    2007-01-01

    Mapping floodplain boundaries using geographical information system (GIS) and digital elevation models (DEMs) was completed in a recent study. However convenient this method may appear at first, the resulting maps potentially can have unaccounted errors. Mapping the floodplain using GIS is faster than mapping manually, and digital mapping is expected to be more common in the future. When mapping is done manually, the experience and judgment of the engineer or geographer completing the mapping and the contour resolution of the surface topography are critical in determining the flood-plain and floodway boundaries between cross sections. When mapping is done digitally, discrepancies can result from the use of the computing algorithm and digital topographic datasets. Understanding the possible sources of error and how the error accumulates through these processes is necessary for the validation of automated digital mapping. This study will evaluate the procedure of floodplain mapping using GIS and a 3 m by 3 m resolution DEM with a focus on the accumulated errors involved in the process. Within the GIS environment of this mapping method, the procedural steps of most interest, initially, include: (1) the accurate spatial representation of the stream centerline and cross sections, (2) properly using a triangulated irregular network (TIN) model for the flood elevations of the studied cross sections, the interpolated elevations between them and the extrapolated flood elevations beyond the cross sections, and (3) the comparison of the flood elevation TIN with the ground elevation DEM, from which the appropriate inundation boundaries are delineated. The study area involved is of relatively low topographic relief; thereby, making it representative of common suburban development and a prime setting for the need of accurately mapped floodplains. This paper emphasizes the impacts of integrating supplemental digital terrain data between cross sections on floodplain delineation

  7. Using maps in genealogy

    USGS Publications Warehouse

    U.S. Geological Survey

    1999-01-01

    Maps are one of many sources you may need to complete a family tree. In genealogical research, maps can provide clues to where our ancestors may have lived and where to look for written records about them. Beginners should master basic genealogical research techniques before starting to use topographic maps.

  8. A Topographic Field Trip of Washington, D.C. - A Cartographic Multimedia Application

    USGS Publications Warehouse

    U.S. Geological Survey

    1999-01-01

    The U.S. Geological Survey (USGS) has produced ?A Topographic Field Trip of Washington, D.C.,' a multimedia CD-ROM that uses topographic maps to tour Washington, D.C. Although designed for the middle school grade level, it can also be used to teach introductory topographic map reading skills to any level. Two versions of ?A Topographic Field Trip of Washington, D.C.,? are available. The first version, for Macintosh? systems only, was developed and produced as a prototype with educational resources funds and is available free of charge. The second version, for dual platforms, Macintosh?, and Windows? systems, is a sales item. The dual platform version contains improvements in content and navigational capabilities.

  9. Image processing of HCMM-satellite thermal images for superposition with other satellite imagery and topographic and thematic maps. [Upper Rhine River Valley and surrounding highlands Switzerland, Germany, and France

    NASA Technical Reports Server (NTRS)

    Gossmann, H.; Haberaecker, P. (Principal Investigator)

    1980-01-01

    The southwestern part of Central Europe between Basal and Frankfurt was used in a study to determine the accuracy with which a regionally bounded HCMM scene could be rectified with respect to a preassigned coordinate system. The scale to which excerpts from HCMM data can be sensibly enlarged and the question of how large natural structures must be in order to be identified in a satellite thermal image with the given resolution were also examined. Relief and forest and population distribution maps and a land use map derived from LANDSAT data were digitalized and adapted to a common reference system and then combined in a single multichannel data system. The control points for geometrical rectification were determined using the coordinates of the reference system. The multichannel scene was evaluated in several different manners such as the correlation of surface temperature and relief, surface temperature and land use, or surface temperature and built up areas.

  10. Accurate electron affinity of Co and fine-structure splittings of C o- via slow-electron velocity-map imaging

    NASA Astrophysics Data System (ADS)

    Chen, Xiaolin; Ning, Chuangang

    2016-05-01

    The high-resolution photoelectron spectra of C o- were obtained via the slow-electron velocity-map imaging method. The electron affinity of cobalt element was determined to be 5341.45 (37 ) c m-1 or 662.256(46) meV. The fine structure of C o- was well resolved. The fine-structure intervals C o-(F34) -C o-(F33) and C o-(F34) -C o-(F32) were found to be 920.9 (6 ) c m-1 and 1550.3 (9 ) c m-1 , respectively. The accuracy was improved by a factor of more than ten with respect to the previous laser photodetachment threshold measurement.

  11. Where Am I? A new case of developmental topographical disorientation.

    PubMed

    Bianchini, Filippo; Palermo, Liana; Piccardi, Laura; Incoccia, Chiara; Nemmi, Federico; Sabatini, Umberto; Guariglia, Cecilia

    2014-03-01

    Recently, developmental topographical disorientation (DTD) was described (Bianchini et al., 2010, J Clin Exp Neuropsychol, 20, 807-27; Iaria & Barton, 2010, Exp Brain Res, 206, 189-96; Iaria, Bogod, Fox, & Barton, 2009, Neuropsychologia, 47, 30-40) as a navigational deficit in the absence of neurological or psychiatric disorders. Here, we reported the case of a healthy subject who presented this disorder. Dr. WAI was a 29-year-old right-handed man with normal development and no clinical history of neurological or psychiatric diseases who was affected by a very pervasive topographical orientation and navigational disorder. A neuroradiological exam confirmed the absence of structural and anatomical alterations of the brain. Dr. WAI was submitted to an extensive neuropsychological examination and to a battery of tests specifically developed to assess developmental topographical disorder. Using this battery, we analysed Dr. WAI's acquisition of navigational information and re-orientation processes. He showed severe DTD accompanied by deficits of different cognitive processes directly or indirectly involved in navigational skills. Dr. WAI showed a deficit in developing cognitive maps, already found in previous cases, plus difficulties in evaluating distances and computing metric environmental features. He represents a further confirmation of the existence of DTD suggesting dissociations within the disorder related to the level of development of the ability to build cognitive maps and the association of different imagery deficits. Dr. WAI can help in shedding some light on the mechanisms underlying lack of development of navigational skills. PMID:23336564

  12. Publication of topographic atlas and control network of Mars

    NASA Technical Reports Server (NTRS)

    Wu, Sherman S. C.; Billideau, Jennifer S.; Spare, Beth A.

    1991-01-01

    To aid planetary studies and the planning of future Mars missions, the Topographic Atlas and Control Network for Mars will be submitted by the end of fiscal year 1992 for publication as a NASA Special Publication. It will consist of reduced versions of 108 1:2 million-scale photomosaics that show contour lines from topographic maps at the same scale, as well as precisely located control points. The control points are from the planetwide network, which is not only instrumental in the compilation of maps at various scales, but is also widely used in other research such as studies of Mars' gravity and atmosphere. An example, a combination of MC 8-NW and -SW, of the photomosaics to be included in the atlas is presented. Contour lines in the figure are at 1-km intervals. The final adjusted ground coordinates and elevations of the 77 control points shown are given in table form. The last column in the table lists the topographic datum (zero elevation) that can be used to compute the solid radius of the control point from the center of mass of Mars. The atlas will also include information such as the adjusted C-matrices of each image, descriptions of the methods used, and their accuracy, and guidelines for users.

  13. Images and topographic relief at the north pole of Venus

    NASA Technical Reports Server (NTRS)

    Leberl, Franz W.; Maurice, Kelly E.; Thomas, John K.; Leff, Craig E.; Wall, Stephen D.

    1992-01-01

    The analysis of unique coverage of the north pole of Venus using a subset of 13 images from a total of about 775 synthetic aperture radar orbits during cycle 1 of the Magellan mission is reported. Images at 13 distinctly different azimuths are reported that range over 360 deg in longitude and that show the topographic relief at vastly different imaging geometries at intervals of about 20 deg. A pair of intersecting or crossing orbits is used to assess the topographic relief with stereo radargrammetric techniques, and to refine this assessment using a multiimage clinometric approach. It is shown that the pole is located in accentuated topography with elevation differences in the range of no more than 1 km. It is concluded that pinpointing the location of the pole from the overlapping images and standard mission data is accurate to within about 100 pixels or 8 km (RMS).

  14. QuantiSNP: an Objective Bayes Hidden-Markov Model to detect and accurately map copy number variation using SNP genotyping data.

    PubMed

    Colella, Stefano; Yau, Christopher; Taylor, Jennifer M; Mirza, Ghazala; Butler, Helen; Clouston, Penny; Bassett, Anne S; Seller, Anneke; Holmes, Christopher C; Ragoussis, Jiannis

    2007-01-01

    Array-based technologies have been used to detect chromosomal copy number changes (aneuploidies) in the human genome. Recent studies identified numerous copy number variants (CNV) and some are common polymorphisms that may contribute to disease susceptibility. We developed, and experimentally validated, a novel computational framework (QuantiSNP) for detecting regions of copy number variation from BeadArray SNP genotyping data using an Objective Bayes Hidden-Markov Model (OB-HMM). Objective Bayes measures are used to set certain hyperparameters in the priors using a novel re-sampling framework to calibrate the model to a fixed Type I (false positive) error rate. Other parameters are set via maximum marginal likelihood to prior training data of known structure. QuantiSNP provides probabilistic quantification of state classifications and significantly improves the accuracy of segmental aneuploidy identification and mapping, relative to existing analytical tools (Beadstudio, Illumina), as demonstrated by validation of breakpoint boundaries. QuantiSNP identified both novel and validated CNVs. QuantiSNP was developed using BeadArray SNP data but it can be adapted to other platforms and we believe that the OB-HMM framework has widespread applicability in genomic research. In conclusion, QuantiSNP is a novel algorithm for high-resolution CNV/aneuploidy detection with application to clinical genetics, cancer and disease association studies. PMID:17341461

  15. Geologic map of Mars

    USGS Publications Warehouse

    Tanaka, Kenneth L.; Skinner, James A.; Dohm, James M.; Irwin, Rossman P., III; Kolb, Eric J.; Fortezzo, Corey M.; Platz, Thomas; Michael, Gregory G.; Hare, Trent M.

    2014-01-01

    This global geologic map of Mars, which records the distribution of geologic units and landforms on the planet's surface through time, is based on unprecedented variety, quality, and quantity of remotely sensed data acquired since the Viking Orbiters. These data have provided morphologic, topographic, spectral, thermophysical, radar sounding, and other observations for integration, analysis, and interpretation in support of geologic mapping. In particular, the precise topographic mapping now available has enabled consistent morphologic portrayal of the surface for global mapping (whereas previously used visual-range image bases were less effective, because they combined morphologic and albedo information and, locally, atmospheric haze). Also, thermal infrared image bases used for this map tended to be less affected by atmospheric haze and thus are reliable for analysis of surface morphology and texture at even higher resolution than the topographic products.

  16. Kilometer-scale topographic roughness of Mercury: Correlation with geologic features and units

    NASA Astrophysics Data System (ADS)

    Kreslavsky, Mikhail A.; Head, James W.; Neumann, Gregory A.; Zuber, Maria T.; Smith, David E.

    2014-12-01

    We present maps of the topographic roughness of the northern circumpolar area of 30 Mercury at kilometer scales. The maps are derived from range profiles obtained by the 31 Mercury Laser Altimeter (MLA) instrument onboard the MErcury Surface, Space 32 ENvironment, Geochemistry, and Ranging (MESSENGER) mission. As measures of 33 roughness, we used the interquartile range of profile curvature at three baselines: 0.7 km, 34 2.8 km, and 11 km. The maps provide a synoptic overview of variations of typical 35 topographic textures. They show a dichotomy between the smooth northern plains and 36 rougher, more heavily cratered terrains. Analysis of the scale dependence of roughness 37 indicates that the regolith on Mercury is thicker than on the Moon by approximately a 38 factor of three. Roughness contrasts within northern volcanic plains of Mercury indicate a 39 younger unit inside Goethe basin and inside another unnamed stealth basin. These new 40 data permit interplanetary comparisons of topographic roughness.

  17. Kilometer-Scale Topographic Roughness of Mercury: Correlation with Geologic Features and Units

    NASA Technical Reports Server (NTRS)

    Kreslavsky, Mikhail A.; Head, James W.; Neumann, Gregory A.; Zuber, Maria T.; Smith, David E.

    2014-01-01

    We present maps of the topographic roughness of the northern circumpolar area of Mercury at kilometer scales. The maps are derived from range profiles obtained by the Mercury Laser Altimeter (MLA) instrument onboard the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. As measures of roughness, we used the interquartile range of profile curvature at three baselines: 0.7 kilometers, 2.8 kilometers, and 11 kilometers. The maps provide a synoptic overview of variations of typical topographic textures. They show a dichotomy between the smooth northern plains and rougher, more heavily cratered terrains. Analysis of the scale dependence of roughness indicates that the regolith on Mercury is thicker than on the Moon by approximately a factor of three. Roughness contrasts within northern volcanic plains of Mercury indicate a younger unit inside Goethe basin and inside another unnamed stealth basin. These new data permit interplanetary comparisons of topographic roughness.

  18. Nomenclature for topographic features on Mercury

    NASA Astrophysics Data System (ADS)

    Burba, G. A.

    The background behind the creation of a nomenclature for the topographic features of Mercury is examined, with particular attention given to developments associated with recent probe studies. The nomenclature is presented in Russian and Latin transcriptions, and problems in the transcription of Mercury topographic names into Russian are considered.

  19. Mapping benefits from updated ifsar data in Alaska: improved source data enables better maps

    USGS Publications Warehouse

    Craun, Kari J.

    2015-01-01

    The U.S. Geological Survey (USGS) and partners in other Federal and State agencies are working collaboratively toward Statewide coverage of interferometric synthetic aperture radar (ifsar) elevation data in Alaska. These data will provide many benefits to a wide range of stakeholders and users. Some applications include development of more accurate and highly detailed topographic maps; improvement of surface water information included in the National Hydrography (NHD) and Watershed Boundary Datasets (WBDs); and use in scientific modeling applications such as calculating glacier surface elevation differences over time and estimating tsunami inundation areas.

  20. PRISM3/GISS Topographic Reconstruction

    USGS Publications Warehouse

    Sohl, Linda E.; Chandler, Mark A.; Schmunk, Robert B.; Mankoff, Ken; Jonas, Jeffrey A.; Foley, Kevin M.; Dowsett, Harry J.

    2009-01-01

    The PRISM3/GISS topographic reconstruction is one of the global data sets incorporated into a new reconstruction for the mid-Piacenzian warm interval of the Pliocene, at about 3.3 to 3.0 Ma. The PRISM3/GISS topography-gridded data set is a digitization of a graphical reconstruction, provided at 2 deg x 2 deg resolution and based on updated paleoaltimetry data and a refined land/ocean mask. Mid-Piacenzian topography as shown in this data set is generally quite similar to modern topography, with three notable differences: (1) the coastline as shown is 25 meters higher than modern sea level, reflecting the hypothesized reduction in ice sheet volume; (2) Hudson Bay is filled in to low elevation, in the absence of evidence for submergence at that time; and (3) the West Antarctic ice sheet is absent, permitting open seaways to exist in Ellsworth and Marie Byrd Lands. Two alternate ice sheet configurations with corresponding vegetation schemes are available; one is a minor modification of the PRISM2 ice reconstruction, and one is derived from the British Antarctic Survey Ice Sheet Model (BAS ISM).

  1. Map Separates

    USGS Publications Warehouse

    U.S. Geological Survey

    2001-01-01

    U.S. Geological Survey (USGS) topographic maps are printed using up to six colors (black, blue, green, red, brown, and purple). To prepare your own maps or artwork based on maps, you can order separate black-and-white film positives or negatives for any color printed on a USGS topographic map, or for one or more of the groups of related features printed in the same color on the map (such as drainage and drainage names from the blue plate.) In this document, examples are shown with appropriate ink color to illustrate the various separates. When purchased, separates are black-and-white film negatives or positives. After you receive a film separate or composite from the USGS, you can crop, enlarge or reduce, and edit to add or remove details to suit your special needs. For example, you can adapt the separates for making regional and local planning maps or for doing many kinds of studies or promotions by using the features you select and then printing them in colors of your choice.

  2. Hawaiian Islands Captured by Shuttle Radar Topographic Mission (SRTM)

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Launched February 11, 2000, the STS-99 Shuttle Radar Topographic Mission (SRTM) was the most ambitious Earth mapping mission to date. A 200-ft long (60 meter) mast supporting the SRTM jutted into space from the Space Shuttle Endeavour. Orbiting some 145 miles (233 kilometers) above Earth, the giant structure was deployed on February 12, 2000 and the C-band and X-band anternae mounted on it quickly went to work mapping parts of the Earth. The SRTM radar was able to penetrate clouds as well as provide its own illumination, independent of daylight, and obtained 3-dimentional topographic images of the world's surface up to the Arctic and Antarctic Circles. The mission completed 222 hours of around the clock radar mapping, gathering enough information to fill more than 20,000 CDs. This image is an example of the data required by the SRTM. This is a view of the three Hawaiian Islands; Molokai (lower left), Lanai (right), and the northwest tip of Maui (upper left). The image brightness corresponds to the strength of radar signal reflected from the ground, while colors show the elevation as measured by SRTM, ranging from blue at the lowest elevations to white at the highest elevations. This image contains 5900 feet (1800 meters) of total relief. SRTM will help local officials to better understand and prepare for volcanic, tidal wave, and earthquake activities.

  3. Mapping Venus: Modeling the Magellan Mission.

    ERIC Educational Resources Information Center

    Richardson, Doug

    1997-01-01

    Provides details of an activity designed to help students understand the relationship between astronomy and geology. Applies concepts of space research and map-making technology to the construction of a topographic map of a simulated section of Venus. (DDR)

  4. Global order and local disorder in brain maps.

    PubMed

    Rothschild, Gideon; Mizrahi, Adi

    2015-07-01

    Maps serve as a ubiquitous organizing principle in the mammalian brain. In several sensory systems, such as audition, vision, and somatosensation, topographic maps are evident throughout multiple levels of brain pathways. Topographic maps, like retinotopy and tonotopy, persist from the receptor surface up to the cortex. Other maps, such as those of orientation preference in the visual cortex, are first created in the cortex itself. Despite the prevalence of topographic maps, it is still not clear what function they subserve. Although maps are topographically smooth at the macroscale, they are often locally heterogeneous. Here, we review studies describing the anatomy and physiology of topographic maps across various spatial scales, from the smooth macroscale to the heterogeneous local microarchitecture, with emphasis on maps of the visual and auditory systems. We discuss the potential advantages of local heterogeneity in brain maps, how they reflect complex cortical connectivity, and how they may impact sensory coding and local computations. PMID:25897872

  5. Topographic visualization of prefix propagation in the internet.

    PubMed

    Cortese, Pier Francesco; Di Battista, Giuseppe; Moneta, Antonello; Patrignani, Maurizio; Pizzonia, Maurizio

    2006-01-01

    We propose a new metaphor for the visualization of prefixes propagation in the Internet. Such a metaphor is based on the concept of topographic map and allows to put in evidence the relative importance of the Internet Service Providers (ISPs) involved in the routing of the prefix. Based on the new metaphor we propose an algorithm for computing layouts and experiment with such algorithm on a test suite taken from the real Internet. The paper extends the visualization approach of the BGPlay service, which is an Internet routing monitoring tool widely used by ISP operators. PMID:17080793

  6. Landslides Identification Using Airborne Laser Scanning Data Derived Topographic Terrain Attributes and Support Vector Machine Classification

    NASA Astrophysics Data System (ADS)

    Pawłuszek, Kamila; Borkowski, Andrzej

    2016-06-01

    Since the availability of high-resolution Airborne Laser Scanning (ALS) data, substantial progress in geomorphological research, especially in landslide analysis, has been carried out. First and second order derivatives of Digital Terrain Model (DTM) have become a popular and powerful tool in landslide inventory mapping. Nevertheless, an automatic landslide mapping based on sophisticated classifiers including Support Vector Machine (SVM), Artificial Neural Network or Random Forests is often computationally time consuming. The objective of this research is to deeply explore topographic information provided by ALS data and overcome computational time limitation. For this reason, an extended set of topographic features and the Principal Component Analysis (PCA) were used to reduce redundant information. The proposed novel approach was tested on a susceptible area affected by more than 50 landslides located on Rożnów Lake in Carpathian Mountains, Poland. The initial seven PCA components with 90% of the total variability in the original topographic attributes were used for SVM classification. Comparing results with landslide inventory map, the average user's accuracy (UA), producer's accuracy (PA), and overall accuracy (OA) were calculated for two models according to the classification results. Thereby, for the PCA-feature-reduced model UA, PA, and OA were found to be 72%, 76%, and 72%, respectively. Similarly, UA, PA, and OA in the non-reduced original topographic model, was 74%, 77% and 74%, respectively. Using the initial seven PCA components instead of the twenty original topographic attributes does not significantly change identification accuracy but reduce computational time.

  7. Precipitation in topographically diverse regions

    NASA Astrophysics Data System (ADS)

    Tarboton, David

    A 1991 AGU Fall Meeting session, Precipitation in Topographically Diverse Regions, focused on the understanding and modeling of precipitation in regions with significant topography, concentrating on the effect of topography on precipitation. Contributions ranged from detailed mesoscale atmospheric models to statistical approaches.Two papers presented detailed physical modeling. A. P. Barros and D. P. Lettenmaier described their work, consisting of a threedimensional finite element model based on the measurement of moist static energy. Application of the model in the Olympic and Cascades mountains demonstrated its potential to model monthly precipitation totals to within 15%. F. Giorgi described some of the work being done at NCAR that is focusing on the regional impacts of global climate change. This work uses a mesoscale meteorological model (Penn State/NCAR MM4) embedded within a general circulation model. There were three papers from the USGS/Colorado State group that described work involving the RHEA-CSU orographic precipitation model that has been coupled with the USGS/s distributed parameter Precipitation Runoff Modeling System (PRMS). The orographic precipitation model has been integrated into a geographic information system to facilitate the use of digital elevation data. The PRMS is based on the concept of hydrologic response units, and the results presented illustrated the scale's sensitivity to these. When rectangular boxes were used instead of the usual response units defined by streams and drainage divides, there was no appreciable degradation in the quality of the simulation. The size and number of response units appears to be more crucial than whether they are demarcated by drainage divides and streams or simply arbitrary.

  8. Positional Accuracy of Airborne Integrated Global Positioning and Inertial Navigation Systems for Mapping in Glen Canyon, Arizona

    USGS Publications Warehouse

    Sanchez, Richard D.; Hothem, Larry D.

    2002-01-01

    High-resolution airborne and satellite image sensor systems integrated with onboard data collection based on the Global Positioning System (GPS) and inertial navigation systems (INS) may offer a quick and cost-effective way to gather accurate topographic map information without ground control or aerial triangulation. The Applanix Corporation?s Position and Orientation Solutions for Direct Georeferencing of aerial photography was used in this project to examine the positional accuracy of integrated GPS/INS for terrain mapping in Glen Canyon, Arizona. The research application in this study yielded important information on the usefulness and limits of airborne integrated GPS/INS data-capture systems for mapping.

  9. Planetary maps - Passports for the mind

    SciTech Connect

    Anderson, C.M. )

    1990-12-01

    The various types of planetary maps are reviewed. Included are basic descriptions of planimetric, topographic, geologic, and digital maps. It is noted that planimetric maps are pictorial representations of a planet's round surface flattened into a plane, such as controlled photomosaic maps and shaded relief maps. Topographic maps, those usually made with data from altimeters and stereoscopic images, have contour lines indicating the shapes and elevations of landforms. Geologic maps carry additional information about landforms, such as rock types, the processes that formed them, and their relative ages. The International Astronomical Union nomenclature system is briefly discussed, pointing out that the Union often assigns themes to areas to be mapped.

  10. High resolution survey for topographic surveying

    NASA Astrophysics Data System (ADS)

    Luh, L. C.; Setan, H.; Majid, Z.; Chong, A. K.; Tan, Z.

    2014-02-01

    In this decade, terrestrial laser scanner (TLS) is getting popular in many fields such as reconstruction, monitoring, surveying, as-built of facilities, archaeology, and topographic surveying. This is due the high speed in data collection which is about 50,000 to 1,000,000 three-dimensional (3D) points per second at high accuracy. The main advantage of 3D representation for the data is that it is more approximate to the real world. Therefore, the aim of this paper is to show the use of High-Definition Surveying (HDS), also known as 3D laser scanning for topographic survey. This research investigates the effectiveness of using terrestrial laser scanning system for topographic survey by carrying out field test in Universiti Teknologi Malaysia (UTM), Skudai, Johor. The 3D laser scanner used in this study is a Leica ScanStation C10. Data acquisition was carried out by applying the traversing method. In this study, the result for the topographic survey is under 1st class survey. At the completion of this study, a standard of procedure was proposed for topographic data acquisition using laser scanning systems. This proposed procedure serves as a guideline for users who wish to utilize laser scanning system in topographic survey fully.

  11. Topographical map series in the Map Room of Institute and Museum of Military History in Budapest, Hungary between 1919-1945: Smaller scale series (1:100,000, 1:200,000, 1:300,000, 1:500,000, 1:750,000) of the territory of Central Europe

    NASA Astrophysics Data System (ADS)

    Jankó, A.; Bánfi, R.

    2009-04-01

    The Royal Hungarian State Mapping Institute kept the smaller scales series of the third military survey of the Austro-Hungarian Monarchy, too, so the scales 1:200,000 and 1:750,000 maps. The results of the supervisions of larger scales were transferred onto these scales, 1:200,000 and 1:750,000 maps, for the territory of Central Europe. In 1943 a scale 1:500,000 aerial map was accomplished, too, for the territory of Pannonian basin. There are many other important series in the Map Room between 1919 and 1945, including the WWII German edition 1:300,000 scale map series of Central Europe and Russia to the Ural Mts.; and a series of scale 1:100,000 for the territory of Poland and Russia between 1939-1940.

  12. Mapping of Glacial Motion and Surface Topography of Hielo Patagonico Norte, Chile, Using Satellite SAR L-band Interferometry Data

    NASA Technical Reports Server (NTRS)

    Rignot, Eric; Forster, Rick; Isacks, Bryan

    1996-01-01

    The first topographic and ice-motion maps of the northwestern flank of Hielo Patagonico Norte (HPN, northern Patagonia Icefield), in Chile, were produced using satellite synthetic-aperture interferometric radar data acquired by NASA's Spaceborne Imaging Radar C instrument in October 1994. The topographic map has a IO m vertical precision with a 30 m horizontal spacing, which should be sufficient to serve as a reference for monitoring future mass changes of the icefield. The ice-motion map is accurate to within 4 mm/ d (or 1/ ma). The radar-derived surface topography and ice velocity are used to estimate the ice discharge from the accumulation area of four outlet glaciers, and the calving flux and mass balance of Glaciar San Rafael. The results demonstrate the use of SAR interferometry for monitoring glaciological parameters on a spatial and temporal scale unattainable by any other means.

  13. MOLA Topographic Constraints on Lava Tube Effusion Rates for Alba Patera, Mars

    NASA Technical Reports Server (NTRS)

    Riedel, S. J.; Sakimoto, S. E. H.

    2002-01-01

    Using high resolution MOLA (Mars Orbiter Laser Altimeter) topographic data to accurately model flow rates, we find that Alba Patera tube-fed flows within the mid to lower flanks could accommodate flow rates between 10 Pa s to 1.308 x 10(exp 6) Pa s. Additional information is contained in the original extended abstract.

  14. Proposal for a study of computer mapping of terrain using multispectral data from ERTS-A for the Yellowstone National Park test site

    NASA Technical Reports Server (NTRS)

    Smedes, H. W. (Principal Investigator); Root, R. R.; Roller, N. E. G.; Despain, D.

    1978-01-01

    The author has identified the following significant results. A terrain map of Yellowstone National Park showed plant community types and other classes of ground cover in what is basically a wild land. The map comprised 12 classes, six of which were mapped with accuracies of 70 to 95%. The remaining six classes had spectral reflectances that overlapped appreciably, and hence, those were mapped less accurately. Techniques were devised for quantitatively comparing the recognition map of the park with control data acquired from ground inspection and from analysis of sidelooking radar images, a thermal IR mosaic, and IR aerial photos of several scales. Quantitative analyses were made in ten 40 sq km test areas. Comparison mechanics were performed by computer with the final results displayed on line printer output. Forested areas were mapped by computer using ERTS data for less than 1/4 the cost of the conventional forest mapping technique for topographic base maps.

  15. Localized damage caused by topographic amplification during the 2010 M7.0 Haiti earthquake

    USGS Publications Warehouse

    Hough, S.E.; Altidor, J.R.; Anglade, D.; Given, D.; Janvier, M.G.; Maharrey, J.Z.; Meremonte, M.; Mildor, B.S.-L.; Prepetit, C.; Yong, A.

    2010-01-01

    Local geological conditions, including both near-surface sedimentary layers and topographic features, are known to significantly influence ground motions caused by earthquakes. Microzonation maps use local geological conditions to characterize seismic hazard, but commonly incorporate the effect of only sedimentary layers. Microzonation does not take into account local topography, because significant topographic amplification is assumed to be rare. Here we show that, although the extent of structural damage in the 2010 Haiti earthquake was primarily due to poor construction, topographic amplification contributed significantly to damage in the district of Petionville, south of central Port-au-Prince. A large number of substantial, relatively well-built structures situated along a foothill ridge in this district sustained serious damage or collapse. Using recordings of aftershocks, we calculate the ground motion response at two seismic stations along the topographic ridge and at two stations in the adjacent valley. Ground motions on the ridge are amplified relative to both sites in the valley and a hard-rock reference site, and thus cannot be explained by sediment-induced amplification. Instead, the amplitude and predominant frequencies of ground motion indicate the amplification of seismic waves by a narrow, steep ridge. We suggest that microzonation maps can potentially be significantly improved by incorporation of topographic effects. ?? 2010 Macmillan Publishers Limited. All rights reserved.

  16. Reduction of Topographic Effect for Curve Number Estimated from Remotely Sensed Imagery

    NASA Astrophysics Data System (ADS)

    Zhang, Wen-Yan; Lin, Chao-Yuan

    2016-04-01

    The Soil Conservation Service Curve Number (SCS-CN) method is commonly used in hydrology to estimate direct runoff volume. The CN is the empirical parameter which corresponding to land use/land cover, hydrologic soil group and antecedent soil moisture condition. In large watersheds with complex topography, satellite remote sensing is the appropriate approach to acquire the land use change information. However, the topographic effect have been usually found in the remotely sensed imageries and resulted in land use classification. This research selected summer and winter scenes of Landsat-5 TM during 2008 to classified land use in Chen-You-Lan Watershed, Taiwan. The b-correction, the empirical topographic correction method, was applied to Landsat-5 TM data. Land use were categorized using K-mean classification into 4 groups i.e. forest, grassland, agriculture and river. Accuracy assessment of image classification was performed with national land use map. The results showed that after topographic correction, the overall accuracy of classification was increased from 68.0% to 74.5%. The average CN estimated from remotely sensed imagery decreased from 48.69 to 45.35 where the average CN estimated from national LULC map was 44.11. Therefore, the topographic correction method was recommended to normalize the topographic effect from the satellite remote sensing data before estimating the CN.

  17. Localized damage caused by topographic amplification during the 2010 M7.0 Haiti earthquake

    NASA Astrophysics Data System (ADS)

    Hough, Susan E.; Altidor, Jean Robert; Anglade, Dieuseul; Given, Doug; Janvier, M. Guillard; Maharrey, J. Zebulon; Meremonte, Mark; Mildor, Bernard Saint-Louis; Prepetit, Claude; Yong, Alan

    2010-11-01

    Local geological conditions, including both near-surface sedimentary layers and topographic features, are known to significantly influence ground motions caused by earthquakes. Microzonation maps use local geological conditions to characterize seismic hazard, but commonly incorporate the effect of only sedimentary layers. Microzonation does not take into account local topography, because significant topographic amplification is assumed to be rare. Here we show that, although the extent of structural damage in the 2010 Haiti earthquake was primarily due to poor construction, topographic amplification contributed significantly to damage in the district of Petionville, south of central Port-au-Prince. A large number of substantial, relatively well-built structures situated along a foothill ridge in this district sustained serious damage or collapse. Using recordings of aftershocks, we calculate the ground motion response at two seismic stations along the topographic ridge and at two stations in the adjacent valley. Ground motions on the ridge are amplified relative to both sites in the valley and a hard-rock reference site, and thus cannot be explained by sediment-induced amplification. Instead, the amplitude and predominant frequencies of ground motion indicate the amplification of seismic waves by a narrow, steep ridge. We suggest that microzonation maps can potentially be significantly improved by incorporation of topographic effects.

  18. Nanomechanical and topographical imaging of living cells by atomic force microscopy with colloidal probes

    NASA Astrophysics Data System (ADS)

    Puricelli, Luca; Galluzzi, Massimiliano; Schulte, Carsten; Podestà, Alessandro; Milani, Paolo

    2015-03-01

    Atomic Force Microscopy (AFM) has a great potential as a tool to characterize mechanical and morphological properties of living cells; these properties have been shown to correlate with cells' fate and patho-physiological state in view of the development of novel early-diagnostic strategies. Although several reports have described experimental and technical approaches for the characterization of cellular elasticity by means of AFM, a robust and commonly accepted methodology is still lacking. Here, we show that micrometric spherical probes (also known as colloidal probes) are well suited for performing a combined topographic and mechanical analysis of living cells, with spatial resolution suitable for a complete and accurate mapping of cell morphological and elastic properties, and superior reliability and accuracy in the mechanical measurements with respect to conventional and widely used sharp AFM tips. We address a number of issues concerning the nanomechanical analysis, including the applicability of contact mechanical models and the impact of a constrained contact geometry on the measured Young's modulus (the finite-thickness effect). We have tested our protocol by imaging living PC12 and MDA-MB-231 cells, in order to demonstrate the importance of the correction of the finite-thickness effect and the change in Young's modulus induced by the action of a cytoskeleton-targeting drug.

  19. Nanomechanical and topographical imaging of living cells by atomic force microscopy with colloidal probes

    SciTech Connect

    Puricelli, Luca; Galluzzi, Massimiliano; Schulte, Carsten; Podestà, Alessandro Milani, Paolo

    2015-03-15

    Atomic Force Microscopy (AFM) has a great potential as a tool to characterize mechanical and morphological properties of living cells; these properties have been shown to correlate with cells’ fate and patho-physiological state in view of the development of novel early-diagnostic strategies. Although several reports have described experimental and technical approaches for the characterization of cellular elasticity by means of AFM, a robust and commonly accepted methodology is still lacking. Here, we show that micrometric spherical probes (also known as colloidal probes) are well suited for performing a combined topographic and mechanical analysis of living cells, with spatial resolution suitable for a complete and accurate mapping of cell morphological and elastic properties, and superior reliability and accuracy in the mechanical measurements with respect to conventional and widely used sharp AFM tips. We address a number of issues concerning the nanomechanical analysis, including the applicability of contact mechanical models and the impact of a constrained contact geometry on the measured Young’s modulus (the finite-thickness effect). We have tested our protocol by imaging living PC12 and MDA-MB-231 cells, in order to demonstrate the importance of the correction of the finite-thickness effect and the change in Young’s modulus induced by the action of a cytoskeleton-targeting drug.

  20. SU-E-J-100: The Combination of Deformable Image Registration and Regions-Of-Interest Mapping Technique to Accomplish Accurate Dose Calculation On Cone Beam Computed Tomography for Esophageal Cancer

    SciTech Connect

    Huang, B-T; Lu, J-Y

    2015-06-15

    Purpose: We introduce a new method combined with the deformable image registration (DIR) and regions-of-interest mapping (ROIM) technique to accurately calculate dose on daily CBCT for esophageal cancer. Methods: Patients suffered from esophageal cancer were enrolled in the study. Prescription was set to 66 Gy/30 F and 54 Gy/30 F to the primary tumor (PTV66) and subclinical disease (PTV54) . Planning CT (pCT) were segmented into 8 substructures in terms of their differences in physical density, such as gross target volume (GTV), venae cava superior (SVC), aorta, heart, spinal cord, lung, muscle and bones. The pCT and its substructures were transferred to the MIM software to readout their mean HU values. Afterwards, a deformable planning CT to daily KV-CBCT image registration method was then utilized to acquire a new structure set on CBCT. The newly generated structures on CBCT were then transferred back to the treatment planning system (TPS) and its HU information were overridden manually with mean HU values obtained from pCT. Finally, the treatment plan was projected onto the CBCT images with the same beam arrangements and monitor units (MUs) to accomplish dose calculation. Planning target volume (PTV) and organs at risk (OARs) from both of the pCT and CBCT were compared to evaluate the dose calculation accuracy. Results: It was found that the dose distribution in the CBCT showed little differences compared to the pCT, regardless of whether PTV or OARs were concerned. Specifically, dose variation in GTV, PTV54, PTV66, SVC, lung and heart were within 0.1%. The maximum dose variation was presented in the spinal cord, which was up to 2.7% dose difference. Conclusion: The proposed method combined with DIR and ROIM technique to accurately calculate dose distribution on CBCT for esophageal cancer is feasible.

  1. Topographic Mapping of the Synaptic Cleft into Adhesive Nanodomains.

    PubMed

    Perez de Arce, Karen; Schrod, Nikolas; Metzbower, Sarah W R; Allgeyer, Edward; Kong, Geoffrey K-W; Tang, Ai-Hui; Krupp, Alexander J; Stein, Valentin; Liu, Xinran; Bewersdorf, Jörg; Blanpied, Thomas A; Lucić, Vladan; Biederer, Thomas

    2015-12-16

    The cleft is an integral part of synapses, yet its macromolecular organization remains unclear. We show here that the cleft of excitatory synapses exhibits a distinct density profile as measured by cryoelectron tomography (cryo-ET). Aiming for molecular insights, we analyzed the synapse-organizing proteins Synaptic Cell Adhesion Molecule 1 (SynCAM 1) and EphB2. Cryo-ET of SynCAM 1 knockout and overexpressor synapses showed that this immunoglobulin protein shapes the cleft's edge. SynCAM 1 delineates the postsynaptic perimeter as determined by immunoelectron microscopy and super-resolution imaging. In contrast, the EphB2 receptor tyrosine kinase is enriched deeper within the postsynaptic area. Unexpectedly, SynCAM 1 can form ensembles proximal to postsynaptic densities, and synapses containing these ensembles were larger. Postsynaptic SynCAM 1 surface puncta were not static but became enlarged after a long-term depression paradigm. These results support that the synaptic cleft is organized on a nanoscale into sub-compartments marked by distinct trans-synaptic complexes. PMID:26687224

  2. EEG Topographic Mapping of Visual and Kinesthetic Imagery in Swimmers.

    PubMed

    Wilson, V E; Dikman, Z; Bird, E I; Williams, J M; Harmison, R; Shaw-Thornton, L; Schwartz, G E

    2016-03-01

    This study investigated differences in QEEG measures between kinesthetic and visual imagery of a 100-m swim in 36 elite competitive swimmers. Background information and post-trial checks controlled for the modality of imagery, swimming skill level, preferred imagery style, intensity of image and task equality. Measures of EEG relative magnitude in theta, low (7-9 Hz) and high alpha (8-10 Hz), and low and high beta were taken from 19 scalp sites during baseline, visual, and kinesthetic imagery. QEEG magnitudes in the low alpha band during the visual and kinesthetic conditions were attenuated from baseline in low band alpha but no changes were seen in any other bands. Swimmers produced more low alpha EEG magnitude during visual versus kinesthetic imagery. This was interpreted as the swimmers having a greater efficiency at producing visual imagery. Participants who reported a strong intensity versus a weaker feeling of the image (kinesthetic) had less low alpha magnitude, i.e., there was use of more cortical resources, but not for the visual condition. These data suggest that low band (7-9 Hz) alpha distinguishes imagery modalities from baseline, visual imagery requires less cortical resources than kinesthetic imagery, and that intense feelings of swimming requires more brain activity than less intense feelings. PMID:26420001

  3. Mapping Alpine Vegetation Location Properties by Dense Matching

    NASA Astrophysics Data System (ADS)

    Niederheiser, Robert; Rutzinger, Martin; Lamprecht, Andrea; Steinbauer, Klaus; Winkler, Manuela; Pauli, Harald

    2016-06-01

    Highly accurate 3D micro topographic mapping in mountain research demands for light equipment and low cost solutions. Recent developments in structure from motion and dense matching techniques provide promising tools for such applications. In the following, the feasibility of terrestrial photogrammetry for mapping topographic location properties of sparsely vegetated areas in selected European mountain regions is investigated. Changes in species composition at alpine vegetation locations are indicators of climate change consequences, such as the pronounced rise of average temperatures in mountains compared to the global average. Better understanding of climate change effects on plants demand for investigations on a micro-topographic scale. We use professional and consumer grade digital single-lens reflex cameras mapping 288 plots each 3 x 3 m on 18 summits in the Alps and Mediterranean Mountains within the GLORIA (GLobal Observation Research Initiative in Alpine environments) network. Image matching tests result in accuracies that are in the order of millimetres in the XY-plane and below 0.5 mm in Z-direction at the second image pyramid level. Reconstructing vegetation proves to be a challenge due to its fine and small structured architecture and its permanent movement by wind during image acquisition, which is omnipresent on mountain summits. The produced 3D point clouds are gridded to 6 mm resolution from which topographic parameters such as slope, aspect and roughness are derived. At a later project stage these parameters will be statistically linked to botanical reference data in order to conclude on relations between specific location properties and species compositions.

  4. 3-Dimensional Topographic Models for the Classroom

    NASA Technical Reports Server (NTRS)

    Keller, J. W.; Roark, J. H.; Sakimoto, S. E. H.; Stockman, S.; Frey, H. V.

    2003-01-01

    We have recently undertaken a program to develop educational tools using 3-dimensional solid models of digital elevation data acquired by the Mars Orbital Laser Altimeter (MOLA) for Mars as well as a variety of sources for elevation data of the Earth. This work is made possible by the use of rapid prototyping technology to construct solid 3-Dimensional models of science data. We recently acquired rapid prototyping machine that builds 3-dimensional models in extruded plastic. While the machine was acquired to assist in the design and development of scientific instruments and hardware, it is also fully capable of producing models of spacecraft remote sensing data. We have demonstrated this by using Mars Orbiter Laser Altimeter (MOLA) topographic data and Earth based topographic data to produce extruded plastic topographic models which are visually appealing and instantly engage those who handle them.

  5. Tectonic and Topographic Effects of Collision Between Two Orogens

    NASA Astrophysics Data System (ADS)

    Forte, A. M.; Cowgill, E.

    2013-12-01

    their modern equivalents. This decrease in fan size implies a similar decrease in drainage area of source catchments, suggesting that the separation between the drainage divide and topographic crest represents a major drainage reorganization event within the GC. Structurally, while the GC has a well-defined pro-wedge, there is no apparent retro-wedge west of 43.5°E. Instead, in this western third the structural geometry is more consistent with that of an orogen-scale anticline. Additionally, in the western and eastern thirds of the range, field mapping and published geodetic surveys indicate that shortening is largely focused in the southern pro-wedge, whereas in the central third of the range, active shortening is localized in an active fold-thrust belt in the retro-wedge. The position of this northern fold-thrust belt coincides with the region in the pro-wedge where the GC are actively colliding with the leading edge of the LC, an arcuate mountain range at the northern edge of the East Anatolian Plateau. We propose that collision between the GC and LC disrupted the pro-wedge of the GC and caused a fundamental structural reorganization within the range. Such disruptions are likely common in the early stages of orogeny.

  6. Simulating Topographic Inversion during Deglaciation

    NASA Astrophysics Data System (ADS)

    Moore, P. L.

    2014-12-01

    High-relief hummocky moraine is thought by many to form by the non-uniform accumulation of supraglacial debris atop downwasting, stagnant ice during deglaciation. Long-lived supraglacial depressions, when filled with debris transported downslope, become hills in the postglacial landscape, while the surrounding highs on the ice surface become inter-hummock valleys and basins. On debris-covered glaciers, debris transport occurs by gradual, slope-dependent processes as well as discrete mass wasting events. Debris production and surface lowering occur during ablation of underlying ice, which in turn depends on the spatial distribution of debris thickness. The coupled heat and mass transport problem lends itself to study using numerical methods similar to those used in mainstream landscape evolution models. A better understanding of the complex relationships between these processes is essential both for more accurate predictions of future ice mass loss and better reconstruction of former ice margins. A one dimensional evolution model has been constructed for investigation of the temporal and spatial relationships between supraglacial processes and postglacial relief. While the heat transfer relationships are well known from field studies on debris-covered glaciers, debris transport relationships are poorly known. Preliminary model analysis suggests that moraine characteristics depend strongly on the ratio of characteristic timescales for surface lowering by ablation and slope degradation by downslope transport. This ratio is therefore sensitive to the form and rate constant of the selected transport relationship, plausibly yielding both high-relief hummocks and nearly-flat plains. Simulations with rapid ablation and relatively slow debris transport yield the greatest initial supraglacial relief, and are most sensitive to the initial configuration of debris sources (e.g., englacial debris bands). However, for such relief to persist as the debris cover thickens, ablation

  7. A flexible modeling package for topographically based watershed hydrology

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Endreny, Theodore A.; Hassett, James M.

    2005-11-01

    An OBJect-oriented TOPographic-based (OBJTOP) hydrological model with a graphical user interface (GUI) was created using object-oriented design (OOD) methods and the objected-oriented programming (OOP) language-C++. OBJTOP presents an array of alternative TOPMODEL hydrological processes of (1) saturation excess or the mixture of infiltration/saturation excess overland flow, (2) exponential or power law decay of hydraulic conductivity with soil depth, (3) topographic index (TI) or soil topographic index (STI) weighting of run-off likelihood, and (4) simulations with or without channel routing, to explain watershed response and increase flexibility and applicability. OBJTOP utilized an object-oriented design (OOD) approach, including the 'inheritance' concept to study individual objects (or processes) at multiple levels, and the 'aggregation' concept to study the interactions of objects (or processes). Further, OOD readily provides for model extension, creating a description of hydrologic processes in a natural, direct, concise, and adaptable manner distinct from procedurally designed and implemented models. The OBJTOP GUI provides an efficient tool for data input, parameter modification, simulation scheme selection and model calibration with three objective functions, including Nash-Sutcliffe. Graphical outputs include time series plots of precipitation depth, partitioned run-off volumes, watertable depth (average or TI/STI based), and map graphics of TI, STI, and depth to watertable. Applications illustrating OBJTOP ability and flexibility include simulation of the TOPMODEL standard Slapton Wood, UK dataset, and simulation of Ward Pound Ridge, NY a small forested catchment with power function decay of hydraulic conductivity and extensive impervious surfaces.

  8. Updating National Topographic Data Base Using Change Detection Methods

    NASA Astrophysics Data System (ADS)

    Keinan, E.; Felus, Y. A.; Tal, Y.; Zilberstien, O.; Elihai, Y.

    2016-06-01

    The traditional method for updating a topographic database on a national scale is a complex process that requires human resources, time and the development of specialized procedures. In many National Mapping and Cadaster Agencies (NMCA), the updating cycle takes a few years. Today, the reality is dynamic and the changes occur every day, therefore, the users expect that the existing database will portray the current reality. Global mapping projects which are based on community volunteers, such as OSM, update their database every day based on crowdsourcing. In order to fulfil user's requirements for rapid updating, a new methodology that maps major interest areas while preserving associated decoding information, should be developed. Until recently, automated processes did not yield satisfactory results, and a typically process included comparing images from different periods. The success rates in identifying the objects were low, and most were accompanied by a high percentage of false alarms. As a result, the automatic process required significant editorial work that made it uneconomical. In the recent years, the development of technologies in mapping, advancement in image processing algorithms and computer vision, together with the development of digital aerial cameras with NIR band and Very High Resolution satellites, allow the implementation of a cost effective automated process. The automatic process is based on high-resolution Digital Surface Model analysis, Multi Spectral (MS) classification, MS segmentation, object analysis and shape forming algorithms. This article reviews the results of a novel change detection methodology as a first step for updating NTDB in the Survey of Israel.

  9. Topographic Controls on Landslide and Debris-Flow Mobility

    NASA Astrophysics Data System (ADS)

    McCoy, S. W.; Pettitt, S.

    2014-12-01

    Regardless of whether a granular flow initiates from failure and liquefaction of a shallow landslide or from overland flow that entrains sediment to form a debris flow, the resulting flow poses hazards to downslope communities. Understanding controls on granular-flow mobility is critical for accurate hazard prediction. The topographic form of granular-flow paths can vary significantly across different steeplands and is one of the few flow-path properties that can be readily altered by engineered control structures such as closed-type check dams. We use grain-scale numerical modeling (discrete element method simulations) of free-surface, gravity-driven granular flows to investigate how different topographic profiles with the same mean slope and total relief can produce notable differences in flow mobility due to strong nonlinearities inherent to granular-flow dynamics. We describe how varying the profile shape from planar, to convex up, to concave up, as well how varying the number, size, and location of check dams along a flow path, changes flow velocity, thickness, discharge, energy dissipation, impact force and runout distance. Our preliminary results highlight an important path dependence for this nonlinear system, show that caution should be used when predicting flow dynamics from path-averaged properties, and provide some mechanics-based guidance for engineering control structures.

  10. MGS Mars Orbiter Laser Altimeter Topographic Profile of Impact Crater

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Among the myriad of interesting landforms sampled by MOLA on its first traverse across the Red Planet on 15 September 1997 is this 13-mile (21-kilometer) diameter impact crater located at 48oN. The figure shows the topography, the computed position of the spacecraft groundtrack (solid line) and the track adjusted to correct for image location error (dashed line). The topographic profile provides some of the first indications of how landscape modification has operated in Martian geologic history. The relief of the crater rim, in combination with the steepness (over 20o) of the inner crater wall, are intriguing in that most craters of this size are much more subdued. The shape of the outer ejecta blanket of the crater likely indicates impact into an H2O rich crust. Issues concerning how craters such as this can be used to understand the properties of the uppermost crust of Mars in regions where the role of water and other volatiles may be important can be addressed with the high spatial and vertical resolution topographic profiles that will be acquired by MOLA once it starts its detailed mapping of the Red Planet in March of 1998.

  11. Development of a seamless multisource topographic/bathymetric elevation model of Tampa Bay

    USGS Publications Warehouse

    Gesch, D.; Wilson, R.

    2001-01-01

    Many applications of geospatial data in coastal environments require knowledge of the nearshore topography and bathymetry. However, because existing topographic and bathymetric data have been collected independently for different purposes, it has been difficult to use them together at the land/water interface owing to differences in format, projection, resolution, accuracy, and datums. As a first step toward solving the problems of integrating diverse coastal datasets, the U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA) are collaborating on a joint demonstration project to merge their data for the Tampa Bay region of Florida. The best available topographic and bathymetric data were extracted from the USGS National Elevation Dataset and the NOAA hydrographic survey database, respectively. Before being merged, the topographic and bathymetric datasets were processed with standard geographic information system tools to place them in a common horizontal reference frame. Also, a key part of the preprocessing was transformation to a common vertical reference through the use of VDatum, a new tool created by NOAA's National Geodetic Survey for vertical datum conversions. The final merged product is a seamless topographic/bathymetric model covering the Tampa Bay region at a grid spacing of 1 arc-second. Topographic LIDAR data were processed and merged with the bathymetry to demonstrate the incorporation of recent third party data sources for several test areas. A primary application of a merged topographic/bathymetric elevation model is for user-defined shoreline delineation, in which the user decides on the tidal condition (for example, low or high water) to be superimposed on the elevation data to determine the spatial position of the water line. Such a use of merged topographic/bathymetric data could lead to the development of a shoreline zone, which could reduce redundant mapping efforts by federal, state, and local agencies

  12. Assessing the influence of topographical data and of the calibration procedure on the estimation of flood inundation probabilities and associated uncertainty

    NASA Astrophysics Data System (ADS)

    Fabio, Pamela; Candela, Angela; Aronica, Giuseppe T.

    2010-05-01

    Floods are considered the most frequent natural disaster world-wide and may have serious socio economic impacts in a community. In order to accomplish flood risk mitigation, flood risk analysis and assessment is required to provide information on current or future flood hazard and risks. Hazard and risk maps involve different data, expertise and effort, depending also to the end-users. In general praxis, more or less advanced deterministic approaches are usually used, but probabilistic approaches seem to be more correct and suited for modelling flood inundation. Two very important matters remain still opened for research: the calibration of hydraulic model (oriented towards the estimation of effective roughness parameters) and the uncertainties (e.g. related to data, model structure and parameterisation) affecting flood hazard mapping results. Here, the new way to incorporate uncertainty in flood hazard will be applied using more accurate topographical data and a new mesh for a complex two-dimensional hyperbolic finite element model. Through a comparison among resulting hazard maps, the influence of these kinds of data will be shown. Moreover, in order to show the influence of the calibration procedure to the final hazard maps, a further comparison will be effected. The calibration of the 2D hydraulic model will be carried out by combining more than one type of observational data. To date, limited applications still exist chiefly because data sets for historical events are quite rare. The procedures were tested on a flood prone area located in the southern part of Sicily, Italy.

  13. High-resolution global topographic index values for use in large-scale hydrological modelling

    NASA Astrophysics Data System (ADS)

    Marthews, Toby; Dadson, Simon; Lehner, Bernhard; Abele, Simon; Gedney, Nicola

    2015-04-01

    Modelling land surface water flow is of critical importance for simulating land-surface fluxes, predicting runoff and water table dynamics and for many other applications of Land Surface Models. Many approaches are based on the popular hydrology model TOPMODEL, and the most important parameter of this model is the well-known topographic index. Here we present new, high-resolution parameter maps of the topographic index for all ice-free land pixels calculated from hydrologically-conditioned HydroSHEDS data using the GA2 algorithm ('GRIDATB 2'). At 15 arc-sec resolution, these layers are four times finer than the resolution of the previously best-available topographic index layers, the Compound Topographic Index of HYDRO1k (CTI). For the largest river catchments occurring on each continent we found that, in comparison with CTI our revised values were up to 20% lower in, e.g., the Amazon. We found the highest catchment means were for the Murray-Darling and Nelson-Saskatchewan rather than for the Amazon and St. Lawrence as found from the CTI. For the majority of large catchments, however, the spread of our new GA2 index values is very similar to those of CTI, yet with more spatial variability apparent at fine scale. We believe these new index layers represent greatly-improved global-scale topographic index values and hope that they will be widely used in land surface modelling applications in the future.

  14. Optical method for the surface topographic characterization of Fresnel lenses

    NASA Astrophysics Data System (ADS)

    Martínez Antón, Juan Carlos; Gómez Pedrero, José Antonio; Alonso Fernández, José; Quiroga, Juan Antonio

    2011-10-01

    Fresnel lenses and other faceted or micro-optic devices are increasingly used in multiple applications like solar light concentrators and illumination devices. As applications are more exigent this characterization is of increasing importance. We present a technique to characterize the surface topography of optical surfaces. It is especially well adapted to Fresnel lenses where abrupt surface slopes are usually difficult to handle in conventional techniques. The method is based on a new photometric strategy able to codify the height information in terms of optical absorption in a liquid. A detailed topographic map is simple to acquire by capturing images of the surface. Some experimental results are presented. A single pixel height resolution of ~0.1 μm is achieved for a height range of ~50 μm. A surface slope analysis is also made achieving a resolution of ~+/-0.15°.

  15. Topographic representations of object size and relationships with numerosity reveal generalized quantity processing in human parietal cortex

    PubMed Central

    Harvey, Ben M.; Fracasso, Alessio; Petridou, Natalia; Dumoulin, Serge O.

    2015-01-01

    Humans and many animals analyze sensory information to estimate quantities that guide behavior and decisions. These quantities include numerosity (object number) and object size. Having recently demonstrated topographic maps of numerosity, we ask whether the brain also contains maps of object size. Using ultra-high-field (7T) functional MRI and population receptive field modeling, we describe tuned responses to visual object size in bilateral human posterior parietal cortex. Tuning follows linear Gaussian functions and shows surround suppression, and tuning width narrows with increasing preferred object size. Object size-tuned responses are organized in bilateral topographic maps, with similar cortical extents responding to large and small objects. These properties of object size tuning and map organization all differ from the numerosity representation, suggesting that object size and numerosity tuning result from distinct mechanisms. However, their maps largely overlap and object size preferences correlate with numerosity preferences, suggesting associated representations of these two quantities. Object size preferences here show no discernable relation to visual position preferences found in visuospatial receptive fields. As such, object size maps (much like numerosity maps) do not reflect sensory organ structure but instead emerge within the brain. We speculate that, as in sensory processing, optimization of cognitive processing using topographic maps may be a common organizing principle in association cortex. Interactions between object size and numerosity maps may associate cognitive representations of these related features, potentially allowing consideration of both quantities together when making decisions. PMID:26483452

  16. Topographic representations of object size and relationships with numerosity reveal generalized quantity processing in human parietal cortex.

    PubMed

    Harvey, Ben M; Fracasso, Alessio; Petridou, Natalia; Dumoulin, Serge O

    2015-11-01

    Humans and many animals analyze sensory information to estimate quantities that guide behavior and decisions. These quantities include numerosity (object number) and object size. Having recently demonstrated topographic maps of numerosity, we ask whether the brain also contains maps of object size. Using ultra-high-field (7T) functional MRI and population receptive field modeling, we describe tuned responses to visual object size in bilateral human posterior parietal cortex. Tuning follows linear Gaussian functions and shows surround suppression, and tuning width narrows with increasing preferred object size. Object size-tuned responses are organized in bilateral topographic maps, with similar cortical extents responding to large and small objects. These properties of object size tuning and map organization all differ from the numerosity representation, suggesting that object size and numerosity tuning result from distinct mechanisms. However, their maps largely overlap and object size preferences correlate with numerosity preferences, suggesting associated representations of these two quantities. Object size preferences here show no discernable relation to visual position preferences found in visuospatial receptive fields. As such, object size maps (much like numerosity maps) do not reflect sensory organ structure but instead emerge within the brain. We speculate that, as in sensory processing, optimization of cognitive processing using topographic maps may be a common organizing principle in association cortex. Interactions between object size and numerosity maps may associate cognitive representations of these related features, potentially allowing consideration of both quantities together when making decisions. PMID:26483452

  17. TOPOGRAPHIC SITE RESPONSE AT HARD ROCK SITES

    NASA Astrophysics Data System (ADS)

    Yong, A. K.; Hough, S. E.

    2009-12-01

    Site (material impedance) and topographic (geometric form) effects are known to be key factors that influence seismic ground motions. To characterize site effects, Yong et al. (2009) developed a terrain-based Vs30 prediction model using an automated classification method (Iwahashi and Pike, 2007) that relied on taxonomic criteria (slope gradient, local convexity and surface texture) developed from geomorphometry to identify 16 terrain types from a 1-km spatial resolution (SRTM30 data) digital elevation model of California. On the basis that the underlying framework for this model contains parameters (esp., local convexity) which aptly describe the geometry (i.e., base to height ratio) of relief features that are known to also control the behavior of ground motions (Bouchon, 1973), we extend our investigation to study topographic effects. Focusing on sites that would generally be considered “hard rock,” the classification scheme distinguishes 7 separate terrain types ranging from “moderately eroded mountains” to “well dissected alpine summits.” Observed 1-Hz amplification factors at Southern California Seismographic Network sites reveal a weak but systematic correlation with these 7 terrain types. Significant scatter is also found within each terrain type; typical standard deviations of logarithmic amplification factors are 0.2-0.3. Considering stations that have high amplification factors, we find some that have apparently been misclassified due to data resolution limitations. Many of the remaining stations with higher than expected amplifications are located on or near topographic peaks or ridges. The unusually high amplification factors at hard-rock sites, typically factors of 1.5-2, can most plausibly be explained as a topographic effect.

  18. Mars polar volatiles: Topographic and geologic setting

    NASA Technical Reports Server (NTRS)

    Murray, B.; Soderblom, L.; Herkenhoff, K.

    1984-01-01

    Progress on a project to elucidate the geological and topographic setting of the Martian polar volatiles is reported. The following accomplishments are enumerated: (1) all of the Mariner 9 imaging data sets available through JPL were acquired and copied; (2) Mariner 9 imagery was investigated in terms of the accuracy of the imaging footprints, dark current, and residual image; (3) the transfer functions of both vidicons were investigated; and (4) the magnitude of the atmospheric scattering was examined.

  19. Impaired allocentric spatial memory underlying topographical disorientation.

    PubMed

    Burgess, Neil; Trinkler, Iris; King, John; Kennedy, Angus; Cipolotti, Lisa

    2006-01-01

    The cognitive processes supporting spatial navigation are considered in the context of a patient (CF) with possible very early Alzheimer's disease who presents with topographical disorientation. Her verbal memory and her recognition memory for unknown buildings, landmarks and outdoor scenes was intact, although she showed an impairment in face processing. By contrast, her navigational ability, quantitatively assessed within a small virtual reality (VR) town, was significantly impaired. Interestingly, she showed a selective impairment in a VR object-location memory test whenever her viewpoint was shifted between presentation and test, but not when tested from the same viewpoint. We suggest that a specific impairment in locating objects relative to the environment rather than relative to the perceived viewpoint (i.e. allocentric rather than egocentric spatial memory) underlies her topographical disorientation. We discuss the likely neural bases of this deficit in the light of related studies in humans and animals, focusing on the hippocampus and related areas. The specificity of our test indicates a new way of assessing topographical disorientation, with possible application to the assessment of progressive dementias such as Alzheimer's disease. PMID:16703955

  20. USGS standard quadrangle maps for emergency response

    USGS Publications Warehouse

    Moore, Laurence R.

    2009-01-01

    The 1:24,000-scale topographic quadrangle was the primary product of the U.S. Geological Survey's (USGS) National Mapping Program from 1947-1992. This map series includes about 54,000 map sheets for the conterminous United States, and is the only uniform map series ever produced that covers this area at such a large scale. This map series partially was revised under several programs, starting as early as 1968, but these programs were not adequate to keep the series current. Through the 1990s the emphasis of the USGS mapping program shifted away from topographic maps and toward more specialized digital data products. Topographic map revision dropped off rapidly after 1999, and stopped completely by 2004. Since 2001, emergency-response and homeland security requirement have revived the question of whether a standard national topographic series is needed. Emergencies such as Hurricane Katrina in 2005 and California wildfires in 2007-08 demonstrated that familiar maps are important to first responders. Maps that have a standard scale, extent, and grids help reduce confusion and save time in emergencies. Traditional maps are designed to allow the human brain to quickly process large amounts of information, and depend on artistic layout and design that cannot be fully automated. In spite of technical advances, creating a traditional, general-purpose topographic map is still expensive. Although the content and layout of traditional topographic maps probably is still desirable, the preferred packaging and delivery of maps has changed. Digital image files are now desired by most users, but to be useful to the emergency-response community, these files must be easy to view and easy to print without specialized geographic information system expertise or software.

  1. The 20th-Century Topographic Survey as Source Data for Long-Term Landscape Studies at Local and Regional Scales

    USGS Publications Warehouse

    Varanka, Dalia

    2006-01-01

    Historical topographic maps are the only systematically collected data resource covering the entire nation for long-term landscape change studies over the 20th century for geographical and environmental research. The paper discusses aspects of the historical U.S. Geological Survey topographic maps that present constraints on the design of a database for such studies. Problems involved in this approach include locating the required maps, understanding land feature classification differences between topographic vs. land use/land cover maps, the approximation of error between different map editions of the same area, and the identification of true changes on the landscape between time periods. Suggested approaches to these issues are illustrated using an example of such a study by the author.

  2. Identifying potential habitat for the endangered Aleutian shield fern using topographical characteristics

    USGS Publications Warehouse

    Duarte, Adam; Wolcott, Daniel M.; Chow, T. Edwin, Ricca, Mark A.

    2012-01-01

    The Aleutian shield fern Polystichum aleuticum is endemic to the Aleutian archipelago of Alaska and is listed as endangered pursuant to the U.S. Endangered Species Act. Despite numerous efforts to discover new populations of this species, only four known populations are documented to date, and information is needed to prioritize locations for future surveys. Therefore, we incorporated topographical habitat characteristics (elevation, slope, aspect, distance from coastline, and anthropogenic footprint) found at known Aleutian shield fern locations into a Geographical Information System (GIS) model to create a habitat suitability map for the entirety of the Andreaonof Islands. A total of 18 islands contained 489.26 km2 of highly suitable and moderately suitable habitat when weighting each factor equally. This study reports a habitat suitability map for the endangered Aleutian shield fern using topographical characteristics, which can be used to assist current and future recovery efforts for the species.

  3. Topographic relationships for design rainfalls over Australia

    NASA Astrophysics Data System (ADS)

    Johnson, F.; Hutchinson, M. F.; The, C.; Beesley, C.; Green, J.

    2016-02-01

    Design rainfall statistics are the primary inputs used to assess flood risk across river catchments. These statistics normally take the form of Intensity-Duration-Frequency (IDF) curves that are derived from extreme value probability distributions fitted to observed daily, and sub-daily, rainfall data. The design rainfall relationships are often required for catchments where there are limited rainfall records, particularly catchments in remote areas with high topographic relief and hence some form of interpolation is required to provide estimates in these areas. This paper assesses the topographic dependence of rainfall extremes by using elevation-dependent thin plate smoothing splines to interpolate the mean annual maximum rainfall, for periods from one to seven days, across Australia. The analyses confirm the important impact of topography in explaining the spatial patterns of these extreme rainfall statistics. Continent-wide residual and cross validation statistics are used to demonstrate the 100-fold impact of elevation in relation to horizontal coordinates in explaining the spatial patterns, consistent with previous rainfall scaling studies and observational evidence. The impact of the complexity of the fitted spline surfaces, as defined by the number of knots, and the impact of applying variance stabilising transformations to the data, were also assessed. It was found that a relatively large number of 3570 knots, suitably chosen from 8619 gauge locations, was required to minimise the summary error statistics. Square root and log data transformations were found to deliver marginally superior continent-wide cross validation statistics, in comparison to applying no data transformation, but detailed assessments of residuals in complex high rainfall regions with high topographic relief showed that no data transformation gave superior performance in these regions. These results are consistent with the understanding that in areas with modest topographic relief, as

  4. The U.S. Geological Survey mapping and cartographic database activities, 2006-2010

    USGS Publications Warehouse

    Craun, Kari J.; Donnelly, John P.; Allord, Gregory J.

    2011-01-01

    The U.S. Geological Survey (USGS) began systematic topographic mapping of the United States in the 1880s, beginning with scales of 1:250,000 and 1:125,000 in support of geological mapping. Responding to the need for higher resolution and more detail, the 1:62,500-scale, 15-minute, topographic map series was begun in the beginning of the 20th century. Finally, in the 1950s the USGS adopted the 1:24,000-scale, 7.5-minute topographic map series to portray even more detail, completing the coverage of the conterminous 48 states of the United States with this series in 1992. In 2001, the USGS developed the vision and concept of The National Map, a topographic database for the 21st century and the source for a new generation of topographic maps (http://nationalmap.gov/). In 2008, the initial production of those maps began with a 1:24,000-scale digital product. In a separate, but related project, the USGS began scanning the existing inventory of historical topographic maps at all scales to accompany the new topographic maps. The USGS also had developed a digital database of The National Atlas of the United States. The digital version of Atlas is now Web-available and supports a mapping engine for small scale maps of the United States and North America. These three efforts define topographic mapping activities of the USGS during the last few years and are discussed below.

  5. Variability of land degradation along topographic transects in two Mediterranean areas

    NASA Astrophysics Data System (ADS)

    Kotb Abd-Elmabod, Sameh; Anaya-Romero, María; Phillips, Jonathan D.; Jordán, Antonio; Muñoz-Rojas, Miriam; de la Rosa, Diego

    2013-04-01

    This study aims to investigate the influence of topography, soil factors and climate conditions on land degradation along topographic transects in two Mediterranean areas: Seville (southern Spain) and El-Fayoum (northern Egypt). Elevation and slope gradient information from both study sites were obtained from Shuttle Radar Topography Mission (SRTM) data, processed using ENVI 4.7. Additionally, topographic transects were developed using ArcGIS 10 software. To represent the highest variability in elevation, lithology, soil and land use in each site, one representative topographic transect from El-Fayoum and two topographic transects from Seville were selected. Soil characteristics along each of the topographic transect were obtained by mapping land surveying and laboratory analyses data. MicroLEIS DSS (Pantanal and Raizal submodels) was used to assess soil contamination with phosphorus, nitrogen, heavy metals and pesticides and water erosion vulnerability along the topographic transects for each study site using soil data, including depth, texture, drainage, carbonate content, salinity, sodium saturation, organic matter content and acidity (pH). Additionally, monthly average values of climate variables (mean temperature, maximum and minimum rainfall and number of rainy days) have been used. The results obtained by Raizal and Pantanal models suggest that lower elevation areas from transects show low vulnerability classes in both degradation processes (water erosion and soil contamination), when compared to uplands. The variation of climate conditions and soil factors along the Seville and El-Fayoum transects were responsible for the observed variability in both soil degradation processes (erosion and contamination). Key words: MicroLEIS DSS, soil degradation, soil factors, topography, DEM

  6. Improving the spatial representation of soil properties and hydrology using topographically derived watershed model initialization processes

    NASA Astrophysics Data System (ADS)

    Easton, Z. M.; Fuka, D.; Collick, A.; Kleinman, P. J. A.; Auerbach, D.; Sommerlot, A.; Wagena, M. B.

    2015-12-01

    Topography exerts critical controls on many hydrologic, geomorphologic, and environmental biophysical processes. Unfortunately many watershed modeling systems use topography only to define basin boundaries and stream channels and do not explicitly account for the topographic controls on processes such as soil genesis, soil moisture distributions and hydrological response. We develop and demonstrate a method that uses topography to spatially adjust soil morphological and soil hydrological attributes [soil texture, depth to the C-horizon, saturated conductivity, bulk density, porosity, and the field capacities at 33kpa (~ field capacity) and 1500kpa (~ wilting point) tensions]. In order to test the performance of the method the topographical adjusted soils and standard SSURGO soil (available at 1:20,000 scale) were overlaid on soil pedon pit data in the Grasslands Soil and Water Research Lab in Resiel, TX. The topographically adjusted soils exhibited significant correlations with measurements from the soil pits, while the SSURGO soil data showed almost no correlation to measured data. We also applied the method to the Grasslands Soil and Water Research watershed using the Soil and Water Assessment Tool (SWAT) model to 15 separate fields as a proxy to propagate changes in soil properties into field scale hydrological responses. Results of this test showed that the topographically adjusted soils resulted better model predictions of field runoff in 50% of the field, with the SSURGO soils preforming better in the remainder of the fields. However, the topographically adjusted soils generally predicted baseflow response more accurately, reflecting the influence of these soil properties on non-storm responses. These results indicate that adjusting soil properties based on topography can result in more accurate soil characterization and, in some cases improve model performance.

  7. Development of Waterfall Cliff Face: An Implication from Multitemporal High-definition Topographic Data

    NASA Astrophysics Data System (ADS)

    Hayakawa, Y. S.; Obanawa, H.

    2015-12-01

    Bedrock knickpoints (waterfalls) often act as erosional front in bedrock rivers, whose geomorphological processes are various. In waterfalls with vertical cliffs, both fluvial erosion and mass movement are feasible to form the landscape. Although morphological changes of such steep cliffs are sometimes visually observed, quantitative and precise measurements of their spatiotemporal distribution have been limited due to poor accessibility to such cliffs. For the clarification of geomorphological processes in such cliffs, multi-temporal mapping of the cliff face at a high resolution can be advantaged by short-range remote sensing approaches. Here we carry out multi-temporal terrestrial laser scanning (TLS), as well as structure-from-motion multi-view stereo (SfM-MVS) photogrammetry based on unmanned aerial system (UAS) for accurate topographic mapping of cliffs around a waterfall. The study site is Kegon Falls in central Japan, having a vertical drop of surface water from top of its overhanging cliff and groundwater outflows from its lower portions. The bedrock consists of alternate layers of jointed andesite lava and conglomerates. The latest major rockfall in 1986 caused approximately 8-m recession of the waterfall lip. Three-dimensional changes of the rock surface were detected by multi-temporal measurements by TLS over years, showing the portions of small rockfalls and surface lowering in the bedrock. Erosion was frequently observed in relatively weak the conglomerates layer, whereas small rockfalls were often found in the andesite layers. Wider areas of the waterfall and cliff were also measured by UAS-based SfM-MVS photogrammetry, improving the mapping quality of the cliff morphology. Point clouds are also projected on a vertical plane to generate a digital elevation model (DEM), and cross-sectional profiles extracted from the DEM indicate the presence of a distinct, 5-10-m deep depression in the cliff face. This appears to have been formed by freeze-thaw and

  8. A geostatistical approach to mapping site response spectral amplifications

    USGS Publications Warehouse

    Thompson, E.M.; Baise, L.G.; Kayen, R.E.; Tanaka, Y.; Tanaka, H.

    2010-01-01

    If quantitative estimates of the seismic properties do not exist at a location of interest then the site response spectral amplifications must be estimated from data collected at other locations. Currently, the most common approach employs correlations of site class with maps of surficial geology. Analogously, correlations of site class with topographic slope can be employed where the surficial geology is unknown. Our goal is to identify and validate a method to estimate site response with greater spatial resolution and accuracy for regions where additional effort is warranted. This method consists of three components: region-specific data collection, a spatial model for interpolating seismic properties, and a theoretical method for computing spectral amplifications from the interpolated seismic properties. We consider three spatial interpolation schemes: correlations with surficial geology, termed the geologic trend (GT), ordinary kriging (OK), and kriging with a trend (KT). We estimate the spectral amplifications from seismic properties using the square root of impedance method, thereby linking the frequency-dependent spectral amplifications to the depth-dependent seismic properties. Thus, the range of periods for which this method is applicable is limited by the depth of exploration. A dense survey of near-surface S-wave slowness (Ss) throughout Kobe, Japan shows that the geostatistical methods give more accurate estimates of Ss than the topographic slope and GT methods, and the OK and KT methods perform equally well. We prefer the KT model because it can be seamlessly integrated with geologic maps that cover larger regions. Empirical spectral amplifications show that the region-specific data achieve more accurate estimates of observed median short-period amplifications than the topographic slope method. ?? 2010 Elsevier B.V.

  9. High-resolution global topographic index values for use in large-scale hydrological modelling

    NASA Astrophysics Data System (ADS)

    Marthews, T. R.; Dadson, S. J.; Lehner, B.; Abele, S.; Gedney, N.

    2015-01-01

    Modelling land surface water flow is of critical importance for simulating land surface fluxes, predicting runoff and water table dynamics and for many other applications of Land Surface Models. Many approaches are based on the popular hydrology model TOPMODEL (TOPography-based hydrological MODEL), and the most important parameter of this model is the well-known topographic index. Here we present new, high-resolution parameter maps of the topographic index for all ice-free land pixels calculated from hydrologically conditioned HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales) data using the GA2 algorithm (GRIDATB 2). At 15 arcsec resolution, these layers are 4 times finer than the resolution of the previously best-available topographic index layers, the compound topographic index of HYDRO1k (CTI). For the largest river catchments occurring on each continent we found that, in comparison with CTI our revised values were up to 20% lower in, e.g. the Amazon. We found the highest catchment means were for the Murray-Darling and Nelson-Saskatchewan rather than for the Amazon and St. Lawrence as found from the CTI. For the majority of large catchments, however, the spread of our new GA2 index values is very similar to those of CTI, yet with more spatial variability apparent at fine scale. We believe these new index layers represent greatly improved global-scale topographic index values and hope that they will be widely used in land surface modelling applications in the future.

  10. Forest Canopy Cover and Height from MISR in Topographically Complex Southwestern US Landscape Assessed with High Quality Reference Data

    NASA Technical Reports Server (NTRS)

    Chopping, Mark; North, Malcolm; Chen, Jiquan; Schaaf, Crystal B.; Blair, J. Bryan; Martonchik, John V.; Bull, Michael A.

    2012-01-01

    This study addresses the retrieval of spatially contiguous canopy cover and height estimates in southwestern USforests via inversion of a geometric-optical (GO) model against surface bidirectional reflectance factor (BRF) estimates from the Multi-angle Imaging SpectroRadiometer (MISR). Model inversion can provide such maps if good estimates of the background bidirectional reflectance distribution function (BRDF) are available. The study area is in the Sierra National Forest in the Sierra Nevada of California. Tree number density, mean crown radius, and fractional cover reference estimates were obtained via analysis of QuickBird 0.6 m spatial resolution panchromatic imagery usingthe CANopy Analysis with Panchromatic Imagery (CANAPI) algorithm, while RH50, RH75 and RH100 (50, 75, and 100 energy return) height data were obtained from the NASA Laser Vegetation Imaging Sensor (LVIS), a full waveform light detection and ranging (lidar) instrument. These canopy parameters were used to drive a modified version of the simple GO model (SGM), accurately reproducing patterns ofMISR 672 nm band surface reflectance (mean RMSE 0.011, mean R2 0.82, N 1048). Cover and height maps were obtained through model inversion against MISR 672 nm reflectance estimates on a 250 m grid.The free parameters were tree number density and mean crown radius. RMSE values with respect to reference data for the cover and height retrievals were 0.05 and 6.65 m, respectively, with of 0.54 and 0.49. MISR can thus provide maps of forest cover and height in areas of topographic variation although refinements are required to improve retrieval precision.

  11. Topographic localization of brain activation in diffuse optical imaging using spherical wavelets

    PubMed Central

    Abdelnour, F; Schmidt, B; Huppert, T J

    2009-01-01

    Diffuse optical imaging is a non-invasive technique that uses near-infrared light to measure changes in brain activity through an array of sensors placed on the surface of the head. Compared to functional MRI, optical imaging has the advantage of being portable while offering the ability to record functional changes in both oxy- and deoxy-hemoglobin within the brain at a high temporal resolution. However, the reconstruction of accurate spatial images of brain activity from optical measurements represents an ill-posed and underdetermined problem that requires regularization. These reconstructions benefit from incorporating prior information about the underlying spatial structure and function of the brain. In this work, we describe a novel image reconstruction approach which uses surface-based wavelets derived from structural MRI to incorporate high-resolution anatomical and structural prior information about the brain. This surface-based approach is used to approximate brain activation patterns through the reconstruction and presentation of topographical (two-dimensional) maps of brain activation directly onto the folded surface of the cortex. The set of wavelet coefficients is directly estimated by a truncated singular-value decomposition based pseudo-inversion of the wavelet projection of the optical forward model. We use a reconstruction metric based on Shannon entropy which quantifies the sparse loading of the wavelet coefficients and is used to determine the optimal truncation and regularization of this inverse model. In this work, examples of the performance of this model are illustrated for several cases of numerical simulation and experimental data with comparison to functional magnetic resonance imaging. PMID:19809125

  12. Topographic localization of brain activation in diffuse optical imaging using spherical wavelets.

    PubMed

    Abdelnour, F; Schmidt, B; Huppert, T J

    2009-10-21

    Diffuse optical imaging is a non-invasive technique that uses near-infrared light to measure changes in brain activity through an array of sensors placed on the surface of the head. Compared to functional MRI, optical imaging has the advantage of being portable while offering the ability to record functional changes in both oxy- and deoxy-hemoglobin within the brain at a high temporal resolution. However, the reconstruction of accurate spatial images of brain activity from optical measurements represents an ill-posed and underdetermined problem that requires regularization. These reconstructions benefit from incorporating prior information about the underlying spatial structure and function of the brain. In this work, we describe a novel image reconstruction approach which uses surface-based wavelets derived from structural MRI to incorporate high-resolution anatomical and structural prior information about the brain. This surface-based approach is used to approximate brain activation patterns through the reconstruction and presentation of topographical (two-dimensional) maps of brain activation directly onto the folded surface of the cortex. The set of wavelet coefficients is directly estimated by a truncated singular-value decomposition based pseudo-inversion of the wavelet projection of the optical forward model. We use a reconstruction metric based on Shannon entropy which quantifies the sparse loading of the wavelet coefficients and is used to determine the optimal truncation and regularization of this inverse model. In this work, examples of the performance of this model are illustrated for several cases of numerical simulation and experimental data with comparison to functional magnetic resonance imaging. PMID:19809125

  13. Topographic control of sorted circle morphology on Svalbard

    NASA Astrophysics Data System (ADS)

    Voigt, Joana; Hauber, Ernst; Reiss, Dennis; Hiesinger, Harald; Johnsson, Andreas; van Gasselt, Stephan; Balme, Matt; Head, Jim; de Verra, Jean-Pierre; Steinbrügge, Gregor; Jaumann, Ralf

    2015-04-01

    Patterned ground is a typical phenomenon in polar, subpolar and alpine regions [1]. As it is commonly (but not necessarily!) related to freeze-thaw cycles, its presence on Mars could possibly point to locations and periods where and when liquid water existed in the recent past [2]. Sorted circles are a class of patterned ground that was tentatively identified in Elysium Planitia (Mars) [3], but this interpretation has been challenged on the basis of physical considerations [4]. Without direct access to potential patterned ground on Mars, the analysis of terrestrial analogues can inform the interpretation of Martian landforms. Svalbard (Norway) offers a wide variety of permafrost features that are morphologically analogous to Martian cold-climate landforms [5]. It hosts some of the best examples of sorted circles on Earth, which are located on the westernmost tip of Brøgger peninsula, on a broad strand flat that is characterized by a series of postglacial beach ridges [6]. Here we report on our analysis of sorted circle morphology (especially their plan-view shape, i.e. their "roundness" or ellipticity) and its correlation with local topography (slopes, curvature). Sorted circle morphology was determined from HRSC-AX images (for details on the flight campaign and image properties see ref [5]) and through field work. Topographic information comes from a 50 cm gridded DEM derived from HRSC-AX stereo images. We measured sorted circle morphology (ellipticity, azimuth of major axis) along a WNW-ESE traverse that runs from the inland towards the sea and is oriented perpendicular to the local beach ridge trend. Selected areas with homogeneous sorted circle appearance were visually mapped, and compared to the average slope, aspect, and the calculated topographic wetness index (TWI). Furthermore the whole traverse was classified into four different morphologies of the sorted patterned ground (sorted circles, sorted "ellipses", sorted nets and areas without patterned ground

  14. CONMAP - USGS MARINE MAPPING PROGRAM.

    USGS Publications Warehouse

    Escowitz, Edward C.

    1985-01-01

    The U. S. Geological Survey has commenced a marine mapping program, CONMAP (the Continental Margin Maps), which is supported by, and dependent on, a foundation of digital data-bases. The goal of the program's first phase is to prepare a series of maps that completely cover the Exclusive Economic Zone. The maps will be prepared using an Albers' Conic Equal-Area Projection at a scale of 1:1,000,000. An initial product of CONMAP will be a series of base map panels portraying the topographic and bathymetric relief, political boundaries and key geographic locations. Additional maps will be prepared which portray other data types and analytical themes.

  15. Topographical and biophysical modeling of vegetation patterns at alpine treeline

    SciTech Connect

    Brown, D.G.

    1992-01-01

    Availability and abundance of several important topo-climatic elements explains much of the variation in the patterns of vegetation along the treeline ecotone. Active geomorphic and biophysical disturbance regimes in alpine areas introduce additional variability on the treeline transition. The purpose of this research was to model the spatial patterns of vegetation communities along the treeline ecotone relative to topo-climatic and disturbances processes. Surrogates of several topographically controlled climatic elements (solar radiation potential, soil moisture potential, and wind/snow potential) were constructed from digital elevation models (DEMs) for a study area in east-central Glacier National Park, Montana. Vegetation communities in the study area were characterized through statistical classification of Landsat Thematic Mapper digital data, field calibration, and validation. Topographical empirical Models of Treeline (TEMTREEs) were constructed to examine the relative importance of factors which affected the treeline transition. TEMTREEs were also evaluated as predictive tools for extending the analysis through additional variables representing multi-scale processes. Empirical models were constructed for selected elevation zones (from 1600 to 2350 meters a.m.s.l.) at 150 meter intervals. The Kappa statistic was used to assess the predictive ability of the models. The results suggested that the elevation gradient accounted for much of the variation in the vegetation patterns at alpine treeline. Geomorphic disturbance patterns, characterized by mapping talus slopes, snow avalanche paths, and slope angles greater than 34 degrees, consistently explained significant variations in the vegetation patterns. This finding suggests that predictions of treeline responses to climatic change must account for potential changes in the frequency and magnitude of geomorphic process disturbances.

  16. UAV photogrammetry for topographic monitoring of coastal areas

    NASA Astrophysics Data System (ADS)

    Gonçalves, J. A.; Henriques, R.

    2015-06-01

    Coastal areas suffer degradation due to the action of the sea and other natural and human-induced causes. Topographical changes in beaches and sand dunes need to be assessed, both after severe events and on a regular basis, to build models that can predict the evolution of these natural environments. This is an important application for airborne LIDAR, and conventional photogrammetry is also being used for regular monitoring programs of sensitive coastal areas. This paper analyses the use of unmanned aerial vehicles (UAV) to map and monitor sand dunes and beaches. A very light plane (SwingletCam) equipped with a very cheap, non-metric camera was used to acquire images with ground resolutions better than 5 cm. The Agisoft Photoscan software was used to orientate the images, extract point clouds, build a digital surface model and produce orthoimage mosaics. The processing, which includes automatic aerial triangulation with camera calibration and subsequent model generation, was mostly automated. To achieve the best positional accuracy for the whole process, signalised ground control points were surveyed with a differential GPS receiver. Two very sensitive test areas on the Portuguese northwest coast were analysed. Detailed DSMs were obtained with 10 cm grid spacing and vertical accuracy (RMS) ranging from 3.5 to 5.0 cm, which is very similar to the image ground resolution (3.2-4.5 cm). Where possible to assess, the planimetric accuracy of the orthoimage mosaics was found to be subpixel. Within the regular coastal monitoring programme being carried out in the region, UAVs can replace many of the conventional flights, with considerable gains in the cost of the data acquisition and without any loss in the quality of topographic and aerial imagery data.

  17. Exploring the Influence of Topographic Correction and SWIR Spectral Information Inclusion on Burnt Scars Detection From High Resolution EO Imagery: A Case Study Using ASTER imagery

    NASA Astrophysics Data System (ADS)

    Said, Yahia A.; Petropoulos, George; Srivastava, Prashant K.

    2014-05-01

    Information on burned area estimates is of key importance in environmental and ecological studies as well as in fire management including damage assessment and planning of post-fire recovery of affected areas. Earth Observation (EO) provides today the most efficient way in obtaining such information in a rapid, consistent and cost-effective manner. The present study aimed at exploring the effect of topographic correction to the burnt area delineation in conditions characteristic of a Mediterranean environment using ASTER high resolution multispectral remotely sensed imagery. A further objective was to investigate the potential added-value of the inclusion of the shortwave infrared (SWIR) bands in improving the retrievals of burned area cartography from the ASTER data. In particular the capability of the Maximum Likelihood (ML), the Support Vector Machines (SVMs) and Object-based Image Analysis (OBIA) classification techniques has been examined herein for the purposes of our study. As a case study is used a typical Mediterranean site on which a fire event occurred in Greece during the summer of 2007, for which post-fire ASTER imagery has been acquired. Our results indicated that the combination of topographic correction (ortho-rectification) with the inclusion of the SWIR bands returned the most accurate results in terms of burnt area mapping. In terms of image processing methods, OBIA showed the best results and found as the most promising approach for burned area mapping with least absolute difference from the validation polygon followed by SVM and ML. All in all, our study provides an important contribution to the understanding of the capability of high resolution imagery such as that from ASTER sensor and corroborates the usefulness particularly of the topographic correction as an image processing step when in delineating the burnt areas from such data. It also provides further evidence that use of EO technology can offer an effective practical tool for the

  18. Cartographic mapping study

    NASA Technical Reports Server (NTRS)

    Wilson, C.; Dye, R.; Reed, L.

    1982-01-01

    The errors associated with planimetric mapping of the United States using satellite remote sensing techniques are analyzed. Assumptions concerning the state of the art achievable for satellite mapping systems and platforms in the 1995 time frame are made. An analysis of these performance parameters is made using an interactive cartographic satellite computer model, after first validating the model using LANDSAT 1 through 3 performance parameters. An investigation of current large scale (1:24,000) US National mapping techniques is made. Using the results of this investigation, and current national mapping accuracy standards, the 1995 satellite mapping system is evaluated for its ability to meet US mapping standards for planimetric and topographic mapping at scales of 1:24,000 and smaller.

  19. Multi-scale characterization of topographic anisotropy

    NASA Astrophysics Data System (ADS)

    Roy, S. G.; Koons, P. O.; Osti, B.; Upton, P.; Tucker, G. E.

    2016-05-01

    We present the every-direction variogram analysis (EVA) method for quantifying orientation and scale dependence of topographic anisotropy to aid in differentiation of the fluvial and tectonic contributions to surface evolution. Using multi-directional variogram statistics to track the spatial persistence of elevation values across a landscape, we calculate anisotropy as a multiscale, direction-sensitive variance in elevation between two points on a surface. Tectonically derived topographic anisotropy is associated with the three-dimensional kinematic field, which contributes (1) differential surface displacement and (2) crustal weakening along fault structures, both of which amplify processes of surface erosion. Based on our analysis, tectonic displacements dominate the topographic field at the orogenic scale, while a combination of the local displacement and strength fields are well represented at the ridge and valley scale. Drainage network patterns tend to reflect the geometry of underlying active or inactive tectonic structures due to the rapid erosion of faults and differential uplift associated with fault motion. Regions that have uniform environmental conditions and have been largely devoid of tectonic strain, such as passive coastal margins, have predominantly isotropic topography with typically dendritic drainage network patterns. Isolated features, such as stratovolcanoes, are nearly isotropic at their peaks but exhibit a concentric pattern of anisotropy along their flanks. The methods we provide can be used to successfully infer the settings of past or present tectonic regimes, and can be particularly useful in predicting the location and orientation of structural features that would otherwise be impossible to elude interpretation in the field. Though we limit the scope of this paper to elevation, EVA can be used to quantify the anisotropy of any spatially variable property.

  20. A brief history of topographical anatomy.

    PubMed

    Standring, Susan

    2016-07-01

    This brief history of topographical anatomy begins with Egyptian medical papyri and the works known collectively as the Greco-Arabian canon, the time line then moves on to the excitement of discovery that characterised the Renaissance, the increasing regulatory and legislative frameworks introduced in the 18th and 19th centuries, and ends with a consideration of the impact of technology that epitomises the period from the late 19th century to the present day. This paper is based on a lecture I gave at the Winter Meeting of the Anatomical Society in Cambridge in December 2015, when I was awarded the Anatomical Society Medal. PMID:27278889

  1. The topographic signature of a Major Typhoon

    NASA Astrophysics Data System (ADS)

    Tseng, Chih-Ming; Lin, Ching-Weei; Dalla Fontana, Giancarlo; Tarolli, Paolo

    2013-04-01

    In August 2009, Typhoon Morakot, characterized by a cumulative rainfall up to 3000 mm in about three days, triggered thousands of landslides and debris flows in Taiwan. The availability of detailed LiDAR surveys before and after the event offers a great opportunity to deeply investigate the topographic signatures of a major Thyphoon, thus providing a way to better understand the Earth Surface Processes and the landscape evolution in a region affected by these phenomena and where the uplift rate is significant. We considered six small catchments, located in the Central Taiwan, affected during the Typhoon Morakot by a different degree of slope failures (totally affected by shallow and deep-seated landslides, and not affected by any erosion). For each of these catchment high resolution Digital Terrain Model (DTM) was derived by LiDAR data, before and after the Thypoon. The scaling regimes of local slope (S) versus drainage area (A) in a loglog diagram served as the basis upon which recognize topographic signatures. The results suggested that for the catchments affected by landslides it is possible to recognize in the third SA scaling regime a characteristic signature of the SA relation: the topographic gradient of the relation tends to vary a little (or slightly increase) increasing the drainage areas. According to literature (Stock and Dietrich, 2003; Tarolli et al., 2009) this behavior of the relation is due to channels incised by landslides and debris flows. Differently, for the catchments without slope failures this signature is not present. These results are interesting because they offer a real example of landscape evolution under rainfall forcing, demonstrating that a Maior Typhoon may significantly affect, in a short time, the SA scaling regimes. The possibility to obtain these information, immediately after an intense event, really represent a strategic tool for a first quantification of the processes that affected and significantly changed the earth surface

  2. Elements of the Chicxulub Impact Structure as revealed in SRTM and surface GPS topographic data

    NASA Astrophysics Data System (ADS)

    Kobrick, M.; Kinsland, G. L.; Sanchez, G.; Cardador, M. H.

    2003-04-01

    Pope et al have utilized elevations from the Petroleos Mexicanos (PEMEX) gravity data files to show that the main component of the surface expression of the Chicxu-lub Impact Structure is a roughly semi-circular, low-relief depression about 90 km in diameter. They also identified other topographic features and the elements of the buried impact which possibly led to the development of these features. Kinsland et al presented a connection between these topographic anomalies, small gravity anomalies and buried structure of the impact. Shaded relief images from recently acquired SRTM elevation data clearly show the circular depression of the crater and the moat/cenote ring. In addition we can readily identify Inner trough 1, Inner trough 2 and Outer trough as defined by Pope et al. The agreement between the topographic maps of Pope et al, Kinsland et al and SRTM data are remarkable considering that the distribution and types of data in the sets are so different. We also have ground topographic data collected with a special "autonomous differ-ential GPS" system during summer 2002. Profiles from these data generally agree with both the gravity data based topographic maps and profiles extracted from the SRTM data. Preliminary analyses of our new data, SRTM and GPS, have uncovered features not previously recognized: 1) as shown by the GPS data the moat/cenote ring consists of two distinct depressions separated by about 10 km...perhaps separate ring faults, 2) in the SRTM data over the southern part of the crater and on southward for perhaps 20 km beyond the moat/ cenote ring there exists a pattern, as yet unexplained, of roughly concentric topographic features whose center lies at about 21deg 40min N and 89deg 25min W, about 50km NNE of the moat/cenote ring center. The corroboration and better definition of the previously recognized topographic features yielded by the two new forms of data strengthens the cases for these fea-tures and for their relevance to the underlying

  3. Ground Surface Visualization Using Red Relief Image Map for a Variety of Map Scales

    NASA Astrophysics Data System (ADS)

    Chiba, T.; Hasi, B.

    2016-06-01

    There are many methods to express topographical features of ground surface. In which, contour map has been the traditional method and along with development of digital data, surface model such as shaded relief map has been using for ground surface expression. Recently, data acquisition has been developed very much quick, demanding more advanced visualization method to express ground surface so as to effectively use the high quality data. In this study, the authors using the Red Relief Image Map (RRIM, Chiba et al., 2008) to express ground surface visualization for a variety of map scales. The authors used 30 m mesh data of SRTM to show the topographical features of western Mongolian and micro-topographical features of ground surface in tectonically active regions of Japan. The results show that, compared to traditional and other similar methods, the RRIM can express ground surface more precisely and 3-dimensionally, suggested its advanced usage for many fields of topographical visualization.

  4. Mapping luna incognita

    NASA Astrophysics Data System (ADS)

    Westfall, John E.

    1990-11-01

    The portion of the moon near the south and southwestern limbs was poorly photographed by the 1960s lunar missions, and is accordingly designated 'luna incognita'. The Association of Lunar and Planetary Observers accordingly undertook a study of this region from 1972 to 1990 which ultimately encompassed 1509 photographs by terrestrial observers, photographs from the Lunar Orbiters IV and V and from Zond 8, radar maps and images, and charts of the moon's limb profile. On these bases, a shaded-relief topographic map was compiled and executed by a computerized 'shading' program at 1:2.5 million scale. This map is presently reproduced in 1:3.5 million scale.

  5. Delineation, characterization, and classification of topographic eminences

    NASA Astrophysics Data System (ADS)

    Sinha, Gaurav

    Topographic eminences are defined as upwardly rising, convex shaped topographic landforms that are noticeably distinct in their immediate surroundings. As opposed to everyday objects, the properties of a topographic eminence are dependent not only on how it is conceptualized, but is also intrinsically related to its spatial extent and its relative location in the landscape. In this thesis, a system for automated detection, delineation and characterization of topographic eminences based on an analysis of digital elevation models is proposed. Research has shown that conceptualization of eminences (and other landforms) is linked to the cultural and linguistic backgrounds of people. However, the perception of stimuli from our physical environment is not subject to cultural or linguistic bias. Hence, perceptually salient morphological and spatial properties of the natural landscape can form the basis for generically applicable detection and delineation of topographic eminences. Six principles of cognitive eminence modeling are introduced to develop the philosophical foundation of this research regarding eminence delineation and characterization. The first step in delineating eminences is to automatically detect their presence within digital elevation models. This is achieved by the use of quantitative geomorphometric parameters (e.g., elevation, slope and curvature) and qualitative geomorphometric features (e.g., peaks, passes, pits, ridgelines, and valley lines). The process of eminence delineation follows that of eminence detection. It is posited that eminences may be perceived either as monolithic terrain objects, or as composites of morphological parts (e.g., top, bottom, slope). Individual eminences may also simultaneously be conceived as comprising larger, higher order eminence complexes (e.g., mountain ranges). Multiple algorithms are presented for the delineation of simple and complex eminences, and the morphological parts of eminences. The proposed eminence

  6. Regional Mapping, Modelling, and Monitoring of Tree Aboveground Biomass Carbon

    NASA Astrophysics Data System (ADS)

    Hudak, Andrew

    2016-04-01

    Airborne lidar collections are preferred for mapping aboveground biomass carbon (AGBC), while historical Landsat imagery are preferred for monitoring decadal scale forest cover change. Our modelling approach tracks AGBC change regionally using Landsat time series metrics; training areas are defined by airborne lidar extents within which AGBC is accurately mapped with high confidence. Geospatial topographic and climate layers are also included in the predictive model. Validation is accomplished using systematically sampled Forest Inventory and Analysis (FIA) plot data that have been independently collected, processed and summarized at the county level. Our goal is to demonstrate that spatially and temporally aggregated annual AGBC map predictions show no bias when compared to annual county-level summaries across the Northwest USA. A prominent source of bias is trees outside forest; much of the more arid portions of our study area meet the FIA definition of non-forest because the tree cover does not exceed their minimum tree cover threshold. We employ detailed tree cover maps derived from high-resolution aerial imagery to extend our AGBC predictions into non-forest areas. We also employ Landsat-derived annual disturbance maps into our mapped AGBC predictions prior to aggregation and validation.

  7. Detecting and Quantifying Topography in Neural Maps

    PubMed Central

    Yarrow, Stuart; Razak, Khaleel A.; Seitz, Aaron R.; Seriès, Peggy

    2014-01-01

    Topographic maps are an often-encountered feature in the brains of many species, yet there are no standard, objective procedures for quantifying topography. Topographic maps are typically identified and described subjectively, but in cases where the scale of the map is close to the resolution limit of the measurement technique, identifying the presence of a topographic map can be a challenging subjective task. In such cases, an objective topography detection test would be advantageous. To address these issues, we assessed seven measures (Pearson distance correlation, Spearman distance correlation, Zrehen's measure, topographic product, topological correlation, path length and wiring length) by quantifying topography in three classes of cortical map model: linear, orientation-like, and clusters. We found that all but one of these measures were effective at detecting statistically significant topography even in weakly-ordered maps, based on simulated noisy measurements of neuronal selectivity and sparse sampling of the maps. We demonstrate the practical applicability of these measures by using them to examine the arrangement of spatial cue selectivity in pallid bat A1. This analysis shows that significantly topographic arrangements of interaural intensity difference and azimuth selectivity exist at the scale of individual binaural clusters. PMID:24505279

  8. Grading More Accurately

    ERIC Educational Resources Information Center

    Rom, Mark Carl

    2011-01-01

    Grades matter. College grading systems, however, are often ad hoc and prone to mistakes. This essay focuses on one factor that contributes to high-quality grading systems: grading accuracy (or "efficiency"). I proceed in several steps. First, I discuss the elements of "efficient" (i.e., accurate) grading. Next, I present analytical results…

  9. Diagnostic value of computerized EEG topographic analysis in epilepsy (preliminary data).

    PubMed

    Rogozea, R; Florea-Ciocoiu, V

    1993-01-01

    A computerized EEG topographic analysis (CETA) was carried out in 69 epileptics in order to evaluate the diagnostic value of such an investigation compared to that of the routine interictal EEG. The spectral frequency analysis of the bioelectrical activity in these patients was accomplished both by the fast Fourier transform and by the autoregression method. The obtained data were used for the spatial analysis of the electrical activity which was performed both by the interhemispheric coherence technique and by the color-coded topographic mapping in frequency bands. The data analysis showed that in 58 (84.1%) of the epileptics in whom routine EEG evidenced focal interictal bioelectrical abnormalities CETA also showed such abnormalities. However, CETA revealed focal abnormalities also in 8 (72.7%) out of the 11 epileptics in whom interictal EEG was interpreted as normal. The data analysis also showed that CETA was more efficient than EEG in the detection of focal abnormalities in the epilepsy with slow graphic elements, in the partial epilepsy, in the epilepsy with late onset and in the therapy-resistant epilepsy. The focal abnormalities evidenced by CETA were more expanded than those evidenced by routine EEG and the topographic maps indicated the focal involvement of a significant number of frequency bands. Considering the results, the authors make some appreciation regarding the diagnostic values of CETA in epilepsy. PMID:8011487

  10. Exploring the topographic evolution of cinder cones

    NASA Astrophysics Data System (ADS)

    Arrowsmith, R.; Zibart, S.; Gleeman, E.; Alfano, F.; Clarke, A. B.; De'Michieli Vitturi, M.; Dekko, R.

    2013-12-01

    The simple original form and monogenetic character of cinder cones make them interesting targets for the study of landscape evolution. Topographic metrics such as cone height-width ratios and histograms of topographic slope yield useful and portable characterizations of cinder cone relative ages. We explored the topographic evolution of cinder cones by simulating surface processes using numerical and physical experimentation approaches and by collecting high resolution topography over exemplary elements of the San Francisco Volcanic field in northern Arizona. We identified a clear distinction in cone form development between those composed of transport-limited cinder only and those with a capping hard agglutinated rim. We employed a fully 2 dimensional numerical implementation of non linear diffusion with spatially variable transport rates. The agglutinate was idealized as an annulus of diminished transport rate. In the laboratory, we used a simple erosion model consisting of fine mist over a cone of fine sand. The agglutinate was represented with a spray adhesive cap. Non-agglutinated cones show a steady decrease in height and increase in width over time, resulting in a lower height-to-width ratios and greater rounding of profiles than agglutinated cones. The presence of an agglutinate top lessens the degree of rounding, producing a concave profile with a resistant 'neck' as the cone flank erodes, in contrast with non-agglutinated cones which develop into convex-concave profiles. The resistant agglutinate protects itself and the material directly underneath it from erosion; this material stays in place while the sediments around it are transported downslope. The slope distributions start out as bimodal: flat and angle of repose. In the non-agglutinated case, the rounding of the cone and broadening of the base produces a more continuous slope distribution with overall progressive slope decrease from the angle of repose and slope increase from the flat base. The

  11. Topographic thresholds in gully development on the hillslopes of communal areas in Ngqushwa Local Municipality, Eastern Cape, South Africa

    NASA Astrophysics Data System (ADS)

    Kakembo, V.; Xanga, W. W.; Rowntree, K.

    2009-09-01

    The relationships between the spatial distribution of gully erosion and topographic thresholds in the form of slope angle, position and configuration, as well as land use change in the form of abandoned lands were examined in several affected catchments of the Eastern Cape Province, South Africa. Land use and permanent gullies were mapped, digitized from orthophoto maps in Arc/info 3.5.2 GIS and converted to shapefiles using ArcView 3.2 GIS. Relationships between the mapped phenomena and topographic variables were sought using a Digital Elevation Model (DEM) in Idrisi Kilimanjaro GIS. A comparison between areas with a high potential for gullying and actual gully erosion was made using the Stream Power Index ( SPI) as a surrogate for critical flow shear stress. Field surveys were also conducted to assess the present condition of the gullied sites as well as to validate DEM derivations. Seventy five percent of the gullied area was noted to lie on abandoned lands. A predominance of gullying in concave bottom lands was also identified. The SPI values highlighted a distinct preferential topographic zone for gully location. A conceptual model depicting the interaction between land use and topographic parameters to induce gully erosion was developed. This should assist local authorities to develop a policy regarding management of abandoned lands.

  12. A remote sensing investigation of elevated sub-horizontal topographic surfaces in the Wichita Mountains, Oklahoma

    NASA Astrophysics Data System (ADS)

    Xue, Liang

    Multiple elevated horizontal to sub-horizontal topographic surfaces are present in the Wichita Mountains, Oklahoma. Elevated topographic surfaces, developed primarily on granite bedrock with gentle slopes of 0.5 to 7°,were investigated using 1) Digital Elevation Models (DEMs) extracted from NAD 27 UTM coordinates, 2) Google Earth imagery, and 3) USGS topographic maps. In the western Wichita Mountains prominent topographic surfaces at elevations of 720 +/- 5 m, 685 +/- 5 m, and 660 +/- 5 m are well preserved on at least four different mountains (e.g., Solder's Peak, King Mt.) and can be correlated with similar surfaces on at least seven different mountains (e.g., Mt. Scott, North Mt.) in the eastern Wichita Mountains. A less well developed surface at 585 +/-5 m is present in the eastern Wichita Mountains and may not be preserved in the western Wichita Mountains. These surfaces are interpreted to be relict pediments or remnants of a more extensive peneplain subsequently dissected as a result of long term time integrated changes in base level, climate, and/or tectonic uplift. Correlation of elevated sub-horizontal surfaces between the western and eastern Wichita Mountains suggests the Wichita Mountains basement behaved as a coherent crustal block since Mid Cenozoic. The presence of multiple elevated, sub-horizontal, regional topographic surfaces throughout the Wichita Mountains complicates direct correlation of these surfaces to the Southern High Plains peneplain using either a linear regression or an exponential fit along a line of projection. Thus, a finer resolution of the timing for individual elevated surfaces in the Wichita Mountains needs to be established.

  13. Unique topographic distribution of greyhound nonsuppurative meningoencephalitis.

    PubMed

    Terzo, Eloisa; McConnell, J Fraser; Shiel, Robert E; McAllister, Hester; Behr, Sebastien; Priestnall, Simon L; Smith, Ken C; Nolan, Catherine M; Callanan, John J

    2012-01-01

    Greyhound nonsuppurative meningoencephalitis is an idiopathic breed-associated fatal meningoencephalitis with lesions usually occurring within the rostral cerebrum. This disorder can only be confirmed by postmortem examination, with a diagnosis based upon the unique topography of inflammatory lesions. Our purpose was to describe the magnetic resonance (MR) imaging features of this disease. Four Greyhounds with confirmed Greyhound nonsuppurative meningoencephalitis were evaluated by MR imaging. Lesions predominantly affected the olfactory lobes and bulbs, frontal, and frontotemporal cortical gray matter, and caudate nuclei bilaterally. Fluid attenuation inversion recovery (FLAIR) and T2 weighted spin-echo (T2W) sequences were most useful to assess the nature, severity, extension, and topographic pattern of lesions. Lesions were predominantly T2-hyperintense and T1-isointense with minimal or absent contrast enhancement. PMID:22742427

  14. Friction Anisotropy with Respect to Topographic Orientation

    PubMed Central

    Yu, Chengjiao; Wang, Q. Jane

    2012-01-01

    Friction characteristics with respect to surface topographic orientation were investigated using surfaces of different materials and fabricated with grooves of different scales. Scratching friction tests were conducted using a nano-indentation-scratching system with the tip motion parallel or perpendicular to the groove orientation. Similar friction anisotropy trends were observed for all the surfaces studied, which are (1) under a light load and for surfaces with narrow grooves, the tip motion parallel to the grooves offers higher friction coefficients than does that perpendicular to them, (2) otherwise, equal or lower friction coefficients are found under this motion. The influences of groove size relative to the diameter of the mating tip (as a representative asperity), surface contact stiffness, contact area, and the characteristic stiction length are discussed. The appearance of this friction anisotropy is independent of material; however, the boundary and the point of trend transition depend on material properties. PMID:23248751

  15. A Neural Basis for Developmental Topographic Disorientation

    PubMed Central

    Aminoff, Elissa M.; Kastner, Sabine; Behrmann, Marlene

    2015-01-01

    Developmental topographic disorientation (DTD) is a life-long condition in which affected individuals are severely impaired in navigating around their environment. Individuals with DTD have no apparent structural brain damage on conventional imaging and the neural mechanisms underlying DTD are currently unknown. Using functional and diffusion tensor imaging, we present a comprehensive neuroimaging study of an individual, J.N., with well defined DTD. J.N. has intact scene-selective responses in the parahippocampal place area (PPA), transverse occipital sulcus, and retrosplenial cortex (RSC), key regions associated with scene perception and navigation. However, detailed fMRI studies probing selective tuning properties of these regions, as well as functional connectivity, suggest that J.N.'s RSC has an atypical response profile and an atypical functional coupling to PPA compared with human controls. This deviant functional profile of RSC is not due to compromised structural connectivity. This comprehensive examination suggests that the RSC may play a key role in navigation-related processing and that an alteration of the RSC's functional properties may serve as the neural basis for DTD. SIGNIFICANCE STATEMENT Individuals with developmental topographic disorientation (DTD) have a life-long impairment in spatial navigation in the absence of brain damage, neurological conditions, or basic perceptual or memory deficits. Although progress has been made in identifying brain regions that subserve normal navigation, the neural basis of DTD is unknown. Using functional and structural neuroimaging and detailed statistical analyses, we investigated the brain regions typically involved in navigation and scene processing in a representative DTD individual, J.N. Although scene-selective regions were identified, closer scrutiny indicated that these areas, specifically the retrosplenial cortex (RSC), were functionally disrupted in J.N. This comprehensive examination of a

  16. The topographic signature of anthropogenic geomorphic processes

    NASA Astrophysics Data System (ADS)

    Tarolli, P.; Sofia, G.

    2014-12-01

    Within an abiotic-dominated context, geomorphologic patterns and dynamics are single expressions of trade-offs between the physical resistance forces, and the mechanical and chemical forces related to climate and erosion. Recently, however, it has become essential for the geomorphological community to take into account also biota as a fundamental geomorphologic agent acting from local to regional scales. However, while there is a recent flourishing literature about the impacts of vegetation on geomorphic processes, the study of anthropogenic pressure on geomorphology is still at its early stages. Humans are indeed among the most prominent geomorphic agents, redistributing land surface, and causing drastic changes to the geomorphic organization of the landscape (e.g. intensive agriculture, urbanization), with direct consequences on land degradation and watershed response. The reconstruction or identification of artificial or anthropogenic topographies, therefore, provides a mechanism for quantifying anthropogenic changes to the landscape systems in the context of the Anthropocene epoch. High-resolution topographic data derived from the recent remote sensing technologies (e.g. lidar, SAR, SfM), offer now new opportunities to recognize better understand geomorphic processes from topographic signatures, especially in engineered landscapes where the direct anthropic alteration of processes is significant. It is possible indeed to better recognize human-induced geomorphic and anthropogenic features (e.g. road networks, agricultural terraces), and the connected erosion. The study presented here may allow improved understanding and targeted mitigation of the processes driving geomorphic changes during urban development and help guide future research directions for development-based watershed studies. Human society is deeply affecting the environment with consequences on the landscape. It is therefore fundamental to establish greater management control over the Earth

  17. Topographic optical profilometry of steep slope micro-optical transparent surfaces.

    PubMed

    Antón, Juan Carlos Martínez; Alonso, Jose; Pedrero, Jose Antonio Gómez

    2015-04-01

    Optical profilometers based on light reflection may fail at surfaces presenting steep slopes and highly curved features. Missed light, interference and diffraction at steps, peaks and valleys are some of the reasons. Consequently, blind areas or profile artifacts may be observed when using common reflection micro-optical profilometers (confocal, scanning interferometers, etc…). The Topographic Optical Profilometry by Absorption in Fluids (TOPAF) essentially avoids these limitations. In this technique an absorbing fluid fills the gap between a reference surface and the surface to profile. By comparing transmission images at two different spectral bands we obtain a reliable topographic map of the surface. In this contribution we develop a model to obtain the profile under micro-optical observation, where high numerical aperture (NA) objectives are mandatory. We present several analytical and experimental results, validating the technique's capabilities for profiling steep slopes and highly curved micro-optical surfaces with nanometric height resolution. PMID:25968777

  18. Implications of topographic relief on the brittle-to-plastic boundary beneath the southern Central Range, Taiwan

    NASA Astrophysics Data System (ADS)

    Cavallotti, C. J.; Lewis, J. C.

    2015-12-01

    The result of the ongoing arc-continent collision between the Eurasian (EU) and Philippine Sea (PSP) plates, Taiwan is an important tool in understanding the real time mechanics of the mountain building process. We show an apparent gap in seismicity beneath Taiwan's Southern Central Range that may represent the presence of a volume of rock lacking the shear strength required to record brittle processes. A spatially accurate 3D map was created, utilizing data recorded for over 8000 seismic events beneath Taiwan and the surrounding area, and shows an elongate aseismic volume trending northeast southwest generally parallel to the topographic grain of the island. Published P-wave data shows an area nearly coincident with the aseismic zone with lower velocities at depths of 7.5km in the west to nearly 40km in the east which suggests a difference in density (and rheology) from the surrounding, seismically active, areas. Strain inversions assuming a micropolar model for crustal deformation suggest systematic changes in strain tensor geometry from east to west across the hypothesized density boundary. Preliminary results indicate that seismogenic strain along the western margin of the aseismic zone accommodates crustal thinning with stretching oblique to the orogen. In contrast, on the east side of the aseismic zone we see crustal thickening with minimum stretching (shortening) subparallel to PSP-EU motion. The profound change in strain geometry suggests that the asiesmic zone is a partially ductile volume of rock caused by interactions of the EU and PSP beneath Taiwan. We hypothesize that if the rheology contrast is sufficient, higher spatial resolution inversions may reveal that events near the seismic/aseismic interface exhibit Andersonian-like behavior wherein one principal strain axis would lie orthogonal at any given point to a surface mapped to this boundary. Alternatively, if the contrast is smaller the inverted strain geometries may vary systematically and provide

  19. Polarization-induced astigmatism caused by topographic masks

    NASA Astrophysics Data System (ADS)

    Ruoff, Johannes; Neumann, Jens Timo; Schmitt-Weaver, Emil; van Setten, Eelco; le Masson, Nicolas; Progler, Chris; Geh, Bernd

    2007-10-01

    With the continuous shrink of feature sizes the pitch of the mask comes closer to the wave length of light. It has been recognized that in this case polarization effects of the mask become much more pronounced and deviations in the diffraction efficiencies from the well-known Kirchhoff approach can no longer be neglected. It is not only the diffraction efficiencies that become polarization-dependent, also the phases of the diffracted orders tend to deviate from Kirchhoff theory when calculated rigorously. This also happens for large structures, where these phase deviations can mimic polarization dependent wave front aberrations, which in the case of polarized illumination can lead to non-negligible focus shifts that depend on the orientation and the features size themselves. This orientation dependence results in a polarization induced astigmatism offset, which can be of the same order of magnitude or even larger as polarization effects stemming from the lens itself. Hence, for correctly predicting polarization induced astigmatism offsets, one has to both consider lens and mask effects at the same time. In this paper we present a comprehensive study of polarized induced phase effects of topographic masks and develop a simple theoretical model that accurately describes the observed effects.

  20. Incorporating the effect of DEM resolution and accuracy for improved flood inundation mapping

    NASA Astrophysics Data System (ADS)

    Saksena, Siddharth; Merwade, Venkatesh

    2015-11-01

    Topography plays a major role in determining the accuracy of flood inundation areas. However, many areas in the United States and around the world do not have access to high quality topographic data in the form of Digital Elevation Models (DEM). For such areas, an improved understanding of the effects of DEM properties such as horizontal resolution and vertical accuracy on flood inundation maps may eventually lead to improved flood inundation modeling and mapping. This study attempts to relate the errors arising from DEM properties such as spatial resolution and vertical accuracy to flood inundation maps, and then use this relationship to create improved flood inundation maps from coarser resolution DEMs with low accuracy. The results from the five stream reaches used in this study show that water surface elevations (WSE) along the stream and the flood inundation area have a linear relationship with both DEM resolution and accuracy. This linear relationship is then used to extrapolate the water surface elevations from coarser resolution DEMs to get water surface elevations corresponding to a finer resolution DEM. Application of this approach show that improved results can be obtained from flood modeling by using coarser and less accurate DEMs, including public domain datasets such as the National Elevation Dataset and Shuttle Radar Topography Mission (SRTM) DEMs. The improvement in the WSE and its application to obtain better flood inundation maps is dependent on the study reach characteristics such as land use, valley shape, reach length and width. Application of the approach presented in this study on more reaches may lead to development of guidelines for flood inundation mapping using coarser resolution and less accurate topographic datasets.

  1. Accurate monotone cubic interpolation

    NASA Technical Reports Server (NTRS)

    Huynh, Hung T.

    1991-01-01

    Monotone piecewise cubic interpolants are simple and effective. They are generally third-order accurate, except near strict local extrema where accuracy degenerates to second-order due to the monotonicity constraint. Algorithms for piecewise cubic interpolants, which preserve monotonicity as well as uniform third and fourth-order accuracy are presented. The gain of accuracy is obtained by relaxing the monotonicity constraint in a geometric framework in which the median function plays a crucial role.

  2. Accurate Finite Difference Algorithms

    NASA Technical Reports Server (NTRS)

    Goodrich, John W.

    1996-01-01

    Two families of finite difference algorithms for computational aeroacoustics are presented and compared. All of the algorithms are single step explicit methods, they have the same order of accuracy in both space and time, with examples up to eleventh order, and they have multidimensional extensions. One of the algorithm families has spectral like high resolution. Propagation with high order and high resolution algorithms can produce accurate results after O(10(exp 6)) periods of propagation with eight grid points per wavelength.

  3. Topographical studies of the nicotinic acetylcholine receptor. [Torpedo californica

    SciTech Connect

    Middlemas, D.S.

    1987-01-01

    All four subunits of the nicotinic acetylcholine receptor in membrane vesicles isolated from Torpedo californica have been labeled with the photoactivated hydrophobic probe, (/sup 3/H)adamantanediazirine, which selectively labels regions of integral membrane proteins in contact with the hydrocarbon core of the lipid bilayer. All four subunits of the acetylcholine receptor in membrane vesicles isolated from Torpedo californica have been labeled with (/sup 3/H)cholesteryl diazoacetate. As this probe incorporates into lipid bilayers analogously to cholesterol, this result indicates that acetylcholine receptor interacts with cholesterol. Since the photogenerated carbene is situated near the lipid-water interface, this probe has potential as a topographic tool for mapping membrane protein structure. The labeling studies with both (/sup 3/H)adamantanediazirine and (/sup 3/H)cholesteryl diazoacetate support the concept that the acetylcholine receptor is a pseudosymmetric complex of homologous subunits, all of which interact with and span the membrane. The synthesis of the fluorine-containing agonists for the Torpedo californica nicotinic acetylcholine receptor, fluoroacetylcholine bromide and p-fluorophenyltrimethylammonium iodide, are described. It is demonstrated that both are agonists using a cation flux assay with acetylcholine receptor enriched membrane vesicles. The affinity cleavage reagent, p-thiocyanophenyltrimethylammonium iodide, specifically cleaves a peptide bond of the nicotinic acetylcholine receptor in membrane vesicles isolated from Torpedo californica. It is demonstrated that this reagent is an agonist using a cation flux assay. The cleavage is blocked by stoichiometric quantities of ..cap alpha..-bungarotoxin.

  4. Previously Unrecognized Large Lunar Impact Basins Revealed by Topographic Data

    NASA Technical Reports Server (NTRS)

    Frey, Herbert V.

    2008-01-01

    The discovery of a large population of apparently buried impact craters on Mars, revealed as Quasi- Circular Depressions (QCDs) in Mars Orbiting Laser Altimeter (MOLA) data [1,2,3] and as Circular Thin Areas (CTAs) [4] in crustal thickness model data [5] leads to the obvious question: are there unrecognized impact features on the Moon and other bodies in the solar system? Early analysis of Clementine topography revealed several large impact basins not previously known [6,7], so the answer certainly is "Yes." How large a population of previously undetected impact basins, their size frequency distribution, and how much these added craters and basins will change ideas about the early cratering history and Late Heavy Bombardment on the Moon remains to be determined. Lunar Orbiter Laser Altimeter (LOLA) data [8] will be able to address these issues. As a prelude, we searched the state-of-the-art global topographic grid for the Moon, the Unified Lunar Control Net (ULCN) [9] for evidence of large impact features not previously recognized by photogeologic mapping, as summarized by Wilhelms [lo].

  5. 19. John and James Dobson Carpet Mills, West parcel, topographical ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. John and James Dobson Carpet Mills, West parcel, topographical plan, 1986. Barton and Martin, Engineers. 'Topographical Plan for Dobson Mills.' Prepared for Rouse Urban Housing, Inc., Philadelphia, Pennsylvania, 1986. - John & James Dobson Carpet Mill (West Parcel), 4041-4055 Ridge Avenue, Philadelphia, Philadelphia County, PA

  6. Topographic and Air-Photo Lineaments in Various Locations Related to Geothermal Exploration in Colorado

    DOE Data Explorer

    Zehner, Richard

    2012-02-01

    Title: Topographic and Air-Photo Lineaments in Various Locations Related to Geothermal Exploration in Colorado Tags: Colorado, lineaments, air-photo, geothermal Summary: These line shapefiles trace apparent topographic and air-photo lineaments in various counties in Colorado. It was made in order to identify possible fault and fracture systems that might be conduits for geothermal fluids, as part of a DOE reconnaissance geothermal exploration program. Description: Geothermal fluids commonly utilize fault and fractures in competent rocks as conduits for fluid flow. Geothermal exploration involves finding areas of high near-surface temperature gradients, along with a suitable “plumbing system” that can provide the necessary permeability. Geothermal power plants can sometimes be built where temperature and flow rates are high. This line shapefile is an attempt to use desktop GIS to delineate possible faults and fracture orientations and locations in highly prospective areas prior to an initial site visit. Geochemical sampling and geologic mapping could then be centered around these possible faults and fractures. To do this, georeferenced topographic maps and aerial photographs were utilized in an existing GIS, using ESRI ArcMap 10.0 software. The USA_Topo_Maps and World_Imagery map layers were chosen from the GIS Server at server.arcgisonline.com, using a UTM Zone 13 NAD27 projection. This line shapefile was then constructed over that which appeared to be through-going structural lineaments in both the aerial photographs and topographic layers, taking care to avoid manmade features such as roads, fence lines, and utility right-of-ways. Still, it is unknown what actual features these lineaments, if they exist, represent. Although the shapefiles are arranged by county, not all areas within any county have been examined for lineaments. Work was focused on either satellite thermal infrared anomalies, known hot springs or wells, or other evidence of geothermal systems

  7. Maps of Quadrangle 3570, Tagab-E-Munjan (505) and Asmar-Kamdesh (506) Quadrangles, Afghanistan

    USGS Publications Warehouse

    U.S. Geological Survey

    2007-01-01

    By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.

  8. Maps of Quadrangle 3568, Polekhomri (503) and Charikar (504) Quadrangles, Afghanistan

    USGS Publications Warehouse

    U.S. Geological Survey

    2007-01-01

    By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.

  9. Maps of Quadrangle 3466, Lal-Sarjangal (507) and Bamyan (508) Quadrangles, Afghanistan

    USGS Publications Warehouse

    U.S. Geological Survey

    2007-01-01

    By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.

  10. Maps of Quadrangle 3366, Gizab (513) and Nawer (514) Quadrangles, Afghanistan

    USGS Publications Warehouse

    U.S. Geological Survey

    2007-01-01

    By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.

  11. Maps of Quadrangle 3670, Jarm-Keshem (223) and Zebak (224) Quadrangles, Afghanistan

    USGS Publications Warehouse

    U.S. Geological Survey

    2007-01-01

    By selecting one of the four series options shown below, namely, -A, -B, -C, and -D for the geologic, topographic, Landsat natural-color, and Landsat false-color maps, respectively, the user will be taken to that map.

  12. Topographically Enhanced Subinertial Currents at Endeavour Ridge

    NASA Astrophysics Data System (ADS)

    Thomson, R. E.; Rabinovich, A. B.; Mihaly, S. F.; Veirs, S.; Stahr, F. R.; McDuff, R. E.; Subbotina, M. M.

    2001-12-01

    We use velocity records collected from moored current meters to examine the effects of seafloor topography and hydrothermal venting on near-bottom (\\~ 2000 m depth) currents flowing over the Endeavour Segment of Juan de Fuca Ridge. Focus is on the 50-m vertical resolution records collected from July-October 2000 near the main Endeavour vent field and on the 2-km lateral resolution records collected from July-October 2001 at three sites within the 100 m deep axial valley. Semidiurnal currents are found to be marginally more energetic than diurnal currents, and flow above the ridge crest is often dominated by wind-generated inertial events (periods \\~ 16 hrs at 48N) and low-frequency (O(10 day) period) clockwise rotary motions. Observations, supported by numerical modeling, reveal marked topographic amplification of subinertial motions within 100 m of the ridge crest. Motions within the diurnal, inertial, and wind-forced frequency bands undergo especially pronounced above-ridge amplification but attenuate equally rapidly within the confines of the narrow (\\~ 1 km) axial valley. Semidiurnal currents are much less affected by the ridge topography and have approximately uniform amplitudes with depth within the first 250 m of the bottom. Within a few tens of meters of the valley floor, the flow is dominated by \\~ 5 cm/s along-axis semidiurnal oscillations and a surprisingly strong (2 to 4 cm/s), persistently northward up-valley flow. The up-valley flow appears to be independent of, and generally counter to, the prevailing flow in the overlying water column. Initial findings suggest that the enhanced near-bottom flow is maintained by an along-valley pressure gradient created by turbulent entrainment of cold (\\~ 2 C) ambient water by the superheated (\\~ 350 C) hydrothermal plumes and low-temperature diffuse flow. If so, the mean-flow dynamics may be analogous to the summer sea-breeze in coastal fjords, with hydrothermal convection playing the role of summertime

  13. Increasing the availability of national mapping products.

    USGS Publications Warehouse

    Roney, J.I.; Ogilvie, B.C.

    1981-01-01

    A discussion of the means employed by the US Geological Survey to facilitate map usage, covering aspects of project Map Accessibility Program including special rolled and folded map packaging, new market testing, parks and campgrounds program, expanded map dealer program, new booklet-type State sales index and catalog and new USGS map reference code. The USGS is seen as the producer of a tremendous nation-wide inventory of topographic and related map products available in unprecedented types, formats and scales, and as endeavouring to increase access to its products. The new USGS map reference code is appended. -J.C.Stone

  14. Geological assessing of urban environments with a systematic mapping survey: The 1:5000 urban geological map of Catalonia

    NASA Astrophysics Data System (ADS)

    Vilà, Miquel; Pi, Roser; Cirés, Jordi; de Paz, Ana; Berástegui, Xavier

    2010-05-01

    The ground features of urban areas and the geologic processes that operate on them are, in general, strongly altered from their natural original condition as a result of anthropogenic activities. Assessing the stability of the ground, the flooding areas, and, the health risk as a consequence of soil pollution, are, among others, fundamental topics of urban areas that require a better understanding. The development of systematic urban geological mapping projects provides valuable resources to address these issues. Since 2007, the Institut Geologic de Catalunya (IGC) runs an urban geological mapping project, to provide accurate geologic information of county capitals and towns of more than 10000 inhabitants of Catalonia. The urban zones of 131 towns will be surveyed for this project, totalizing an area of about 2200 km2 to be mapped in 15 years. According to the 2008 census, the 82 % of the population of Catalonia (7.242.458 inhabitants) lives in the areas to be mapped in this project. The mapping project integrates in a GIS environment the following subjects: - Data from pre-existing geotechnical reports, historical geological and topographical maps and, from historical aerial photographs. - Data from available borehole databases. - Geological characterization of outcrops inside the urban network and neighbouring areas. - Geological, chemical and physical characterisation of representative rocks, sediments and soils. - Ortophotographs (0.5 m pixel size) and digital elevation models (5 meter grid size) made from historical aerial photographs, to depict land use changes, artificial deposits and geomorphological elements that are either hidden or destroyed by urban sprawl. - Detailed geological mapping of quaternary sediments, subsurface bedrock and artificial deposits. - Data from subsurface prospection in areas with insufficient or confuse data. - 3D modelling of the main geological surfaces such as the top of the pre-quaternary basement. All the gathered data is

  15. Impact of Different Topographic Corrections on Prediction Accuracy of Foliage Projective Cover (fpc) in a Topographically Complex Terrain

    NASA Astrophysics Data System (ADS)

    Ediriweera, S.; Pathirana, S.; Danaher, T.; Nichols, D.; Moffiet, T.

    2012-07-01

    Quantitative retrieval of land surface biological parameters (e.g. foliage projective cover [FPC] and Leaf Area Index) is crucial for forest management, ecosystem modelling, and global change monitoring applications. Currently, remote sensing is a widely adopted method for rapid estimation of surface biological parameters in a landscape scale. Topographic correction is a necessary pre-processing step in the remote sensing application for topographically complex terrain. Selection of a suitable topographic correction method on remotely sensed spectral information is still an unresolved problem. The purpose of this study is to assess the impact of topographic corrections on the prediction of FPC in hilly terrain using an established regression model. Five established topographic corrections [C, Minnaert, SCS, SCS+C and processing scheme for standardised surface reflectance (PSSSR)] were evaluated on Landsat TM5 acquired under low and high sun angles in closed canopied subtropical rainforest and eucalyptus dominated open canopied forest, north-eastern Australia. The effectiveness of methods at normalizing topographic influence, preserving biophysical spectral information, and internal data variability were assessed by statistical analysis and by comparing field collected FPC data. The results of statistical analyses show that SCS+C and PSSSR perform significantly better than other corrections, which were on less overcorrected areas of faintly illuminated slopes. However, the best relationship between FPC and Landsat spectral responses was obtained with the PSSSR by producing the least residual error. The SCS correction method was poor for correction of topographic effect in predicting FPC in topographically complex terrain.

  16. Neural Activity during Voluntary Movements in Each Body Representation of the Intracortical Microstimulation-Derived Map in the Macaque Motor Cortex

    PubMed Central

    Kunori, Nobuo; Murata, Yumi

    2016-01-01

    In order to accurately interpret experimental data using the topographic body map identified by conventional intracortical microstimulation (ICMS), it is important to know how neurons in each division of the map respond during voluntary movements. Here we systematically investigated neuronal responses in each body representation of the ICMS map during a reach-grasp-retrieval task that involves the movements of multiple body parts. The topographic body map in the primary motor cortex (M1) generally corresponds to functional divisions of voluntary movements; neurons at the recording sites in each body representation with movement thresholds of 10 μA or less were differentially activated during the task, and the timing of responses was consistent with the movements of the body part represented. Moreover, neurons in the digit representation responded differently for the different types of grasping. In addition, the present study showed that neural activity depends on the ICMS current threshold required to elicit body movements and the location of the recording on the cortical surface. In the ventral premotor cortex (PMv), no correlation was found between the response properties of neurons and the body representation in the ICMS map. Neural responses specific to forelimb movements were often observed in the rostral part of PMv, including the lateral bank of the lower arcuate limb, in which ICMS up to 100 μA evoked no detectable movement. These results indicate that the physiological significance of the ICMS-derived maps is different between, and even within, areas M1 and PMv. PMID:27494282

  17. The Geometry of Visual Cortical Maps.

    PubMed

    Alonso, Jose Manuel

    2016-08-17

    The primary visual cortex has a map of multiple visual parameters whose topographic relations remain poorly understood. A new study (Nauhaus et al., 2016) reveals a nearly geometric map-topography that coexists within a remarkably precise representation of visual space. PMID:27537480

  18. Topographically mediated ice stream subglacial drainage networks

    NASA Astrophysics Data System (ADS)

    Hiester, J.; Sergienko, O. V.; Hulbe, C. L.

    2016-02-01

    Satellite laser altimetry reveals short timescale changes in Antarctic ice sheet surface elevation that are suggested to be driven by subglacial water transport and storage. Here details of the interaction between the dynamics of ice stream flow, subglacial water system, and bed elevation relief are examined in the context of idealized, heterogeneous bed geometries. Using a two-way coupled model of ice and subglacial water flow, we show that basal topography controls the temporal and spatial variability of the sub-ice stream hydraulic system. The orientation and characteristic dimensions of the topographic undulations determine the morphology (connected subglacial ponds or channel-like subglacial water features) and timescales of the sub-ice stream drainage system. The short-term (several years to decades) variability of the simulated coupled ice stream/subglacial water system suggests that the short-term surface variations detected in remote sensing observations may be indicative of a rapidly evolving subglacial water system. Our simulations also show that interaction between ice flow and the highly dynamic subglacial water system has a strong effect on effective stress in the ice. Large effective stress magnitudes arise over areas where the basal traction is characterized by strong spatial gradients, that is, transitions from high to low basal traction or vise versa. These transitions migrate on multiyear timescales and thus cause large effective stress variability on the same temporal scales.

  19. Enhanced precision CD measurements via topographic modeling

    NASA Astrophysics Data System (ADS)

    Henstra, Alexander; Jackman, James J.

    1994-05-01

    To evaluate the rigorousness of existing algorithms for critical dimension (CD) linewidth measurements in the SEM, a Monte Carlo program was developed to model the topographic signal of line-and-space patterns for both backscattered and secondary electrons. The line cross-section is assumed to be a perfect trapezoid. In this paper we present the results of the modeling of submicron photoresist lines on a silicon substrate for primary beam energies

  20. A gimbal platform stabilization for topographic applications

    SciTech Connect

    Michele, Mangiameli Giuseppe, Mussumeci

    2015-03-10

    The aim of this work is the stabilization of a Gimbal platform for optical sensors acquisitions in topographic applications using mobile vehicles. The stabilization of the line of sight (LOS) consists in tracking the command velocity in presence of nonlinear noise due to the external environment. The hardware architecture is characterized by an Ardupilot platform that allows the control of both the mobile device and the Gimbal. Here we developed a new approach to stabilize the Gimbal platform, which is based on neural network. For the control system, we considered a plant that represents the transfer function of the servo system control model for an inertial stabilized Gimbal platform. The transductor used in the feed-back line control is characterized by the Rate Gyro transfer function installed onboard of Ardupilot. For the simulation and investigation of the system performance, we used the Simulink tool of Matlab. Results show that the hardware/software approach is efficient, reliable and cheap for direct photogrammetry, as well as for general purpose applications using mobile vehicles.

  1. Integrated biomechanical and topographical surface characterization (IBTSC)

    NASA Astrophysics Data System (ADS)

    Löberg, Johanna; Mattisson, Ingela; Ahlberg, Elisabet

    2014-01-01

    In an attempt to reduce the need for animal studies in dental implant applications, a new model has been developed which combines well-known surface characterization methods with theoretical biomechanical calculations. The model has been named integrated biomechanical and topographical surface characterization (IBTSC), and gives a comprehensive description of the surface topography and the ability of the surface to induce retention strength with bone. IBTSC comprises determination of 3D-surface roughness parameters by using 3D-scanning electron microscopy (3D-SEM) and atomic force microscopy (AFM), and calculation of the ability of different surface topographies to induce retention strength in bone by using the local model. Inherent in this integrated approach is the use of a length scale analysis, which makes it possible to separate different size levels of surface features. The IBTSC concept is tested on surfaces with different level of hierarchy, induced by mechanical as well as chemical treatment. Sequential treatment with oxalic and hydrofluoric acid results in precipitated nano-sized features that increase the surface roughness and the surface slope on the sub-micro and nano levels. This surface shows the highest calculated shear strength using the local model. The validity, robustness and applicability of the IBTSC concept are demonstrated and discussed.

  2. Considerations on geomorphological maps for territorial planning in the Modena Apennines (Northern Italy)

    NASA Astrophysics Data System (ADS)

    Castaldini, D.; Ghinoi, A.; Maccaferri, A.

    2012-02-01

    This contribution shows, through some examples, that the current instability processes sometimes do not completely correspond (concerning presence, location, state of activity and/or extent) with those mapped by PTCP Hydrogeological Hazard Maps, which is the document used by the Province Administration for its territorial planning. The differences highlighted are due to different causes. One of them is the fact that the PTCP Hydrogeological Hazard Maps are practically derived from the Regional Geological maps in which superficial deposits have secondary importance, while bedrock and structural-tectonic aspects are given the highest relevance. Another cause is represented by the very active and intense geomorphological dynamics of the Apennines which may produce or reactivate instability conditions. An important aspect to underline is that the PTCP Hydrogeological Hazard Maps identify areas with planning constraints, which have effects at a municipal scale; it does so by starting from a cartographical basis whose primary aim is not the definition of instability processes and whose updating is not homogeneous. Taking into account this aspect, the PTCP Hydrogeological Hazard Maps should be updated not only on the base of traditional geological mapping, but also following the criteria of detailed geomorphological mapping which can precisely define the genesis, dynamics and morphometry of instability phenomena. An important consideration, in relation to territorial planning, is that the PTCP Hydrogeological Hazard Maps should be used just as a "base document", which requires more necessary detailed deepening at the municipal scale, accomplished through accurate geomorphological mapping, at least for the areas that are going to be urbanized. The geomorphological mapping should also update those elements of the landscape which could have changed from the official topographic base map. Detailed geomorphological mapping, possibly undertaken with the methodology proposed in

  3. A structural fabric defined by topographic lineaments: Correlation with Tertiary deformation of Ellesmere and Axel Heiberg Islands, Canadian Arctic

    NASA Technical Reports Server (NTRS)

    Oakey, Gordon

    1994-01-01

    Digital topographic contours from four 1:250000 scale maps have been gridded to produce a digital elevation model for part of Ellesmere and Axel Heiberg islands in the Canadian Arctic Islands. Gradient calculations were used to define both east and west dipping slopes defining a pattern of lineaments that have been compared with mapped geological structures. In ice-covered areas, where geological mapping was not possible, well-defined topographic lineaments have been identified and are correlated to extensions of major structural features. The northeast-southwest patterns of both topographic lineaments and mapped structures are strongly unimodal and support a single compressive event oriented at 67 deg west of north. This orientation is coincidental with the convergence direction calculated from the kinematic poles of rotation for Greenland relative to North America between 56 and 35 Ma. A minor secondary peak at 70 east of north is observed for thrust and normal fault solutions and is not directly related to the predicted convergence direction. Whether this represents a unique phase of deformation or is a subcomponent of a single event is not known. The agreement of structural components, lineament orientations, and convergence direction suggests an overwhelming over print of Eurekan deformation on any preexisting structural fabric. This study confirms, for the first time, an excellent compatibility between geological and geophysical constraints for the timing and geometry of the Eurekan orogeny.

  4. Accurate measurement of time

    NASA Astrophysics Data System (ADS)

    Itano, Wayne M.; Ramsey, Norman F.

    1993-07-01

    The paper discusses current methods for accurate measurements of time by conventional atomic clocks, with particular attention given to the principles of operation of atomic-beam frequency standards, atomic hydrogen masers, and atomic fountain and to the potential use of strings of trapped mercury ions as a time device more stable than conventional atomic clocks. The areas of application of the ultraprecise and ultrastable time-measuring devices that tax the capacity of modern atomic clocks include radio astronomy and tests of relativity. The paper also discusses practical applications of ultraprecise clocks, such as navigation of space vehicles and pinpointing the exact position of ships and other objects on earth using the GPS.

  5. Accurate quantum chemical calculations

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.; Taylor, Peter R.

    1989-01-01

    An important goal of quantum chemical calculations is to provide an understanding of chemical bonding and molecular electronic structure. A second goal, the prediction of energy differences to chemical accuracy, has been much harder to attain. First, the computational resources required to achieve such accuracy are very large, and second, it is not straightforward to demonstrate that an apparently accurate result, in terms of agreement with experiment, does not result from a cancellation of errors. Recent advances in electronic structure methodology, coupled with the power of vector supercomputers, have made it possible to solve a number of electronic structure problems exactly using the full configuration interaction (FCI) method within a subspace of the complete Hilbert space. These exact results can be used to benchmark approximate techniques that are applicable to a wider range of chemical and physical problems. The methodology of many-electron quantum chemistry is reviewed. Methods are considered in detail for performing FCI calculations. The application of FCI methods to several three-electron problems in molecular physics are discussed. A number of benchmark applications of FCI wave functions are described. Atomic basis sets and the development of improved methods for handling very large basis sets are discussed: these are then applied to a number of chemical and spectroscopic problems; to transition metals; and to problems involving potential energy surfaces. Although the experiences described give considerable grounds for optimism about the general ability to perform accurate calculations, there are several problems that have proved less tractable, at least with current computer resources, and these and possible solutions are discussed.

  6. Basis and methods of NASA airborne topographic mapper lidar surveys for coastal studies

    USGS Publications Warehouse

    Brock, John C.; Wright, C. Wayne; Sallenger, Asbury H.; Krabill, William B.; Swift, Robert N.

    2002-01-01

    This paper provides an overview of the basic principles of airborne laser altimetry for surveys of coastal topography, and describes the methods used in the acquisition and processing of NASA Airborne Topographic Mapper (ATM) surveys that cover much of the conterminous US coastline. This form of remote sensing, also known as "topographic lidar", has undergone extremely rapid development during the last two decades, and has the potential to contribute within a wide range of coastal scientific investigations. Various airborne laser surveying (ALS) applications that are relevant to coastal studies are being pursued by researchers in a range of Earth science disciplines. Examples include the mapping of "bald earth" land surfaces below even moderately dense vegetation in studies of geologic framework and hydrology, and determination of the vegetation canopy structure, a key variable in mapping wildlife habitats. ALS has also proven to be an excellent method for the regional mapping of geomorphic change along barrier island beaches and other sandy coasts due to storms or long-term sedimentary processes. Coastal scientists are adopting ALS as a basic method in the study of an array of additional coastal topics. ALS can provide useful information in the analysis of shoreline change, the prediction and assessment of landslides along seacliffs and headlands, examination of subsidence causing coastal land loss, and in predicting storm surge and tsunami inundation.

  7. Application of terrestrial LiDAR topographic data to reconstruct offset geomorphic markers along the Fuyun strike-slip fault, Xinjiang, China

    NASA Astrophysics Data System (ADS)

    Etchebes, M.; Tapponnier, P.; Klinger, Y.; Van Der Woerd, J.; Xu, X.; Xinzhe, S.; Xibin, T.; Rizza, M.; Hang, T. Lok

    2012-04-01

    Tectonically offset geomorphic markers such as stream channels, terrace risers, alluvial fan surfaces and other types of ridges and troughs record the surface signature of successive earthquakes on active faults. Increasingly detailed 3D surface measurements, together with multiple age constraints, now yield a much-improved understanding of the long-term seismic behavior of such faults. Using sub-metric-resolution Quickbird optical satellite images, we obtained a dense horizontal offset dataset (553 measurements) along the right-lateral Fuyun fault. The most recent rupture along this fault, which is remarkably well preserved due to the arid climate, was generated by the Ms 7.9, august 11, 1931 Fuyun earthquake. For 5 successive earthquakes of similar size, the dataset is consistent with characteristic seismic behavior (≈ 6 ± 1 m of co-seismic slip). To complement and validate this dataset, we acquired terrestrial LiDAR topographic data over a total length of 7.5 km at 4 sites where multiples of the 1931 offsets were measured on Quickbird images. Using the new LiDAR DEMs obtained, we were able to map fault scarps more accurately, and the restoration of horizontal offset measurements was improved using apparent vertical offsets. The identification and definition of the markers with the 3D LiDAR data is unambiguous, and qualitative differences in the apparent ages of the markers may be assessed, increasing the confidence level in the reconstructions. On the thrust segments of the rupture, knickpoint retreat can be quantified, opening the way to a better understanding of the interaction between erosion and seismic surface deformation in shaping the landforms. Field observations, HR optical satellite images and LiDAR topographic data ideally complement one another to test the repeatability of offset measurements and constrain the densest possible vertical and horizontal slip distributions along active faults. By combining them, we are starting to build unique

  8. Topographic Phase Recovery from Stacked ERS Interferometry and a Low-Resolution Digital Elevation Model

    NASA Technical Reports Server (NTRS)

    Sandwell, David T.; Sichoix, Lydie; Frey, Herbert V. (Technical Monitor)

    2000-01-01

    A hybrid approach to topographic recovery from ERS interferometry is developed and assessed. Tropospheric/ionospheric artifacts, imprecise orbital information, and layover are key issues in recovering topography and surface deformation from repeat-pass interferometry. Previously, we developed a phase gradient approach to stacking interferograms to reduce these errors and also to reduce the short-wavelength phase noise (see Sandwell arid Price [1998] and Appendix A). Here the method is extended to use a low-resolution digital elevation model to constrain long-wavelength phase errors and an iteration scheme to minimize errors in the computation of phase gradient. We demonstrate the topographic phase recovery on 16-m postings using 25 ERS synthetic aperture radar images from an area of southern California containing 2700 m of relief. On the basis of a comparison with 81 GPS monuments, the ERS derived topography has a typical absolute accuracy of better than 10 m except in areas of layover. The resulting topographic phase enables accurate two-pass, real-time interferometry even in mountainous areas where traditional phase unwrapping schemes fail. As an example, we form a topography-free (127-m perpendicular baseline) interferogram spanning 7.5 years; fringes from two major earthquakes and a seismic slip on the San Andreas Fault are clearly isolated.

  9. Topographic Distributions of Emergent Trees in Tropical Forests of the Osa Peninsula, Costa Rica

    NASA Astrophysics Data System (ADS)

    Balzotti, C.; Asner, G. P.; Taylor, P.; Cole, R. J.; Osborne, B. B.; Cleveland, C. C.; Porder, S.; Townsend, A. R.

    2015-12-01

    Tropical rainforests are reservoirs of terrestrial carbon and biodiversity. Large and often emergent trees store disproportionately large amounts of aboveground carbon and greatly influence the structure and functioning of tropical rainforests. Despite their importance, controls on the abundance and distribution of emergent trees are largely unknown across tropical landscapes. Conventional field approaches are limited in their ability to characterize patterns in emergent trees across vast landscapes with varying environmental conditions and floristic composition. Here we used a high-resolution light detection and ranging (LiDAR) sensor, aboard the Carnegie Airborne Observatory Airborne Taxonomic Mapping System (CAO-AToMS), to examine the abundance and distribution of tall emergent tree canopies (ETC) relative to surrounding tree canopies (STC), across the Osa Peninsula, a geologically and topographically diverse region of Costa Rica. The abundance of ETC was clearly influenced by fine-scale topographic variation, with distribution patterns that held across a variety of geologic substrates. Specifically, the density of ETC was much greater on lower slopes and in valleys, compared to upper slopes and ridges. Furthermore, using the CAO high-fidelity imaging spectrometer, ETC had a different spectral signature than that of the STC. Most notably, ETC had lower foliar N than STC, which was verified with an independent field survey of canopy leaf chemistry. The underlying mechanisms to explain the topographic-dependence of ETCs and linkages to canopy N are unknown, and remain an important area of research.

  10. Development of a grid-cell topographic surface for Okefenokee Swamp, Georgia

    USGS Publications Warehouse

    Loftin, C.S.; Rasberry, W.; Kitchens, W.M.

    2000-01-01

    The Okefenokee Swamp is a 160,000 ha freshwater wetland in Southeast Georgia, USA that developed in a landscape basin. Hydrologic variability across the swamp suggests that water-surface elevations are not uniform across the swamp. The topographic surface map discussed herein was developed to describe the swamp topography at local to landscape scales and relate the swamp peat- and sand-surface elevations to elevation above mean sea level. These data were then used to relate water-surface elevations across the swamp so that the swamp hydrologic environment could be described spatially and temporally with a spatial hydrology model. The swamp was divided into 5 sub-basins that reflect similar seasonal hydrodynamics but also indicate local conditions unique to the basins. Topographic gradient influences water-level dynamics in the western swamp (2 sub-basins), which is dominated by the Suwannee River floodplain. The eastern swamp (3 sub-basins) is terraced, and the regional hydrology is driven less by topographic gradient and more by precipitation and evapotranspiration volumes. The relatively steep gradient and berm and lake features in the western swamp's Suwannee River floodplain limit the spatial extent of the Suwannee River sill's effects, whereas system sensitivities to evapotranspiration rates are more important drivers of hydrology in the eastern swamp.

  11. Precise topographic surface measurements of warm and cold large image detectors for astronomical instrumentations

    NASA Astrophysics Data System (ADS)

    Deiries, Sebastian; Iwert, Olaf; Stroebele, Stefan

    2014-07-01

    This paper describes ESO's surface measurement device for large image detectors in astronomy. The machine was equipped with a sub-micrometer laser displacement sensor and is fully automated with LabView. On the example of newly developed curved CCDs, which are envisaged for future astronomical instruments, it was demonstrated that this machine can exactly determine the topographic surfaces of detectors. This works even at cryogenic temperatures through a dewar window. Included is the calculation of curvature radii from these cold curved CCDs after spherical fitting with MATLAB. In addition (and interesting for calibration of instruments) the micro-movements of the detector inside the cryostat are mapped.

  12. Generation of topographic terrain models utilizing synthetic aperture radar and surface level data

    NASA Technical Reports Server (NTRS)

    Imhoff, Marc L. (Inventor)

    1991-01-01

    Topographical terrain models are generated by digitally delineating the boundary of the region under investigation from the data obtained from an airborne synthetic aperture radar image and surface elevation data concurrently acquired either from an airborne instrument or at ground level. A set of coregistered boundary maps thus generated are then digitally combined in three dimensional space with the acquired surface elevation data by means of image processing software stored in a digital computer. The method is particularly applicable for generating terrain models of flooded regions covered entirely or in part by foliage.

  13. Accurate maser positions for MALT-45

    NASA Astrophysics Data System (ADS)

    Jordan, Christopher; Bains, Indra; Voronkov, Maxim; Lo, Nadia; Jones, Paul; Muller, Erik; Cunningham, Maria; Burton, Michael; Brooks, Kate; Green, James; Fuller, Gary; Barnes, Peter; Ellingsen, Simon; Urquhart, James; Morgan, Larry; Rowell, Gavin; Walsh, Andrew; Loenen, Edo; Baan, Willem; Hill, Tracey; Purcell, Cormac; Breen, Shari; Peretto, Nicolas; Jackson, James; Lowe, Vicki; Longmore, Steven

    2013-10-01

    MALT-45 is an untargeted survey, mapping the Galactic plane in CS (1-0), Class I methanol masers, SiO masers and thermal emission, and high frequency continuum emission. After obtaining images from the survey, a number of masers were detected, but without accurate positions. This project seeks to resolve each maser and its environment, with the ultimate goal of placing the Class I methanol maser into a timeline of high mass star formation.

  14. Topographic Change of the Dichotomy Boundary Suggested by Crustal Inversion

    NASA Technical Reports Server (NTRS)

    Neumann, G. A.

    2004-01-01

    Linear negative gravity anomalies in Acidalia Planitia along the eastern edge of Tempe Terra and along the northern edge of Arabia Terra have been noted in Mars Global Surveyor gravity fields. Once proposed to represent buried fluvial channels, it is now believed that these gravity troughs mainly arise from partial compensation of the hemispheric dichotomy topographic scarp. A recent inversion for crustal structure finds that mantle compensation of the scarp is offset from the present-day topographic expression of the dichotomy boundary. The offset suggests that erosion or other forms of mass wasting occurred after lithosphere thickened and no longer accomodated topographic change through viscous relaxation.

  15. Accurate ab initio-based DMBE potential energy surface for HLi2(X 2A') via scaling of the external correlation

    NASA Astrophysics Data System (ADS)

    Song, Yu-Zhi; Li, Yong-Qing; Gao, Shou-Bao; Meng, Qing-Tian

    2014-01-01

    A globally accurate potential energy surface is reported for the electronic ground-state HLi2 by fitting ab initio energies to double many-body expansion formalism. The total 3726 ab initio energies used to map the HLi2 potential energy surface are calculated using the multi-reference configuration interaction method, with their dynamical correlation being semiempirically corrected by the double many-body expansion-scaled external correlation method. The current potential energy surface generates an excellent fit of the ab initio energies, showing a small root-mean squared derivation of 0.636 kcal mol-1. The topographical features of the HLi2 potential energy surface are examined in detail, which concludes that the H + Li2(X 1Σg) → Li + LiH(X 1Σ) reaction is essentially barrierless and the exothermicity is calculated to be 33.668 kcal mol-1, thus corroborates the available experimental and theoretical results.

  16. Evaluation of LiDAR Imagery as a Tool for Mapping the Northern San Andreas Fault in Heavily Forested Areas of Mendocino and Sonoma Counties, California

    NASA Astrophysics Data System (ADS)

    Prentice, C. S.; Koehler, R. D.; Baldwin, J. N.; Harding, D. J.

    2004-12-01

    We are mapping in detail active traces of the San Andreas Fault in Mendocino and Sonoma Counties in northern California, using recently acquired airborne LiDAR (also known as ALSM) data. The LiDAR data set provides a powerful new tool for mapping geomorphic features related to the San Andreas Fault because it can be used to produce high-resolution images of the ground surfaces beneath the forest canopy along the 70-km-long section of the fault zone encompassed by the data. Our effort represents the first use of LiDAR data to map active fault traces in a densely vegetated region along the San Andreas Fault. We are using shaded relief images generated from bare-earth DEMs to conduct detailed mapping of fault-related geomorphic features (e.g. scarps, offset streams, linear valleys, shutter ridges, and sag ponds) between Fort Ross and Point Arena. Initially, we map fault traces digitally, on-screen, based only on the geomorphology interpreted from LiDAR images. We then conduct field reconnaissance using the initial computer-based maps in order to verify and further refine our mapping. We found that field reconnaissance is of utmost importance in producing an accurate and detailed map of fault traces. Many lineaments identified as faults from the on-screen images were determined in the field to be old logging roads or other features unrelated to faulting. Also, in areas where the resolution of LiDAR data is poor, field reconnaissance, coupled with topographic maps and aerial photographs, permits a more accurate location of fault-related geomorphic features. LiDAR images are extremely valuable as a base for field mapping in this heavily forested area, and the use of LiDAR is far superior to traditional mapping techniques relying only on aerial photography and 7.5 minute USGS quadrangle topographic maps. Comparison with earlier mapping of the northern San Andreas fault (Brown and Wolfe, 1972) shows that in some areas the LiDAR data allow a correction of the fault trace

  17. Hydrological networks and associated topographic variation as templates for the spatial organization of tropical forest vegetation.

    PubMed

    Detto, Matteo; Muller-Landau, Helene C; Mascaro, Joseph; Asner, Gregory P

    2013-01-01

    An understanding of the spatial variability in tropical forest structure and biomass, and the mechanisms that underpin this variability, is critical for designing, interpreting, and upscaling field studies for regional carbon inventories. We investigated the spatial structure of tropical forest vegetation and its relationship to the hydrological network and associated topographic structure across spatial scales of 10-1000 m using high-resolution maps of LiDAR-derived mean canopy profile height (MCH) and elevation for 4930 ha of tropical forest in central Panama. MCH was strongly associated with the hydrological network: canopy height was highest in areas of positive convexity (valleys, depressions) close to channels draining 1 ha or more. Average MCH declined strongly with decreasing convexity (transition to ridges, hilltops) and increasing distance from the nearest channel. Spectral analysis, performed with wavelet decomposition, showed that the variance in MCH had fractal similarity at scales of ∼30-600 m, and was strongly associated with variation in elevation, with peak correlations at scales of ∼250 m. Whereas previous studies of topographic correlates of tropical forest structure conducted analyses at just one or a few spatial grains, our study found that correlations were strongly scale-dependent. Multi-scale analyses of correlations of MCH with slope, aspect, curvature, and Laplacian convexity found that MCH was most strongly related to convexity measured at scales of 20-300 m, a topographic variable that is a good proxy for position with respect to the hydrological network. Overall, our results support the idea that, even in these mesic forests, hydrological networks and associated topographical variation serve as templates upon which vegetation is organized over specific ranges of scales. These findings constitute an important step towards a mechanistic understanding of these patterns, and can guide upscaling and downscaling. PMID:24204610

  18. Hydrological Networks and Associated Topographic Variation as Templates for the Spatial Organization of Tropical Forest Vegetation

    PubMed Central

    Detto, Matteo; Muller-Landau, Helene C.; Mascaro, Joseph; Asner, Gregory P.

    2013-01-01

    An understanding of the spatial variability in tropical forest structure and biomass, and the mechanisms that underpin this variability, is critical for designing, interpreting, and upscaling field studies for regional carbon inventories. We investigated the spatial structure of tropical forest vegetation and its relationship to the hydrological network and associated topographic structure across spatial scales of 10–1000 m using high-resolution maps of LiDAR-derived mean canopy profile height (MCH) and elevation for 4930 ha of tropical forest in central Panama. MCH was strongly associated with the hydrological network: canopy height was highest in areas of positive convexity (valleys, depressions) close to channels draining 1 ha or more. Average MCH declined strongly with decreasing convexity (transition to ridges, hilltops) and increasing distance from the nearest channel. Spectral analysis, performed with wavelet decomposition, showed that the variance in MCH had fractal similarity at scales of ∼30–600 m, and was strongly associated with variation in elevation, with peak correlations at scales of ∼250 m. Whereas previous studies of topographic correlates of tropical forest structure conducted analyses at just one or a few spatial grains, our study found that correlations were strongly scale-dependent. Multi-scale analyses of correlations of MCH with slope, aspect, curvature, and Laplacian convexity found that MCH was most strongly related to convexity measured at scales of 20–300 m, a topographic variable that is a good proxy for position with respect to the hydrological network. Overall, our results support the idea that, even in these mesic forests, hydrological networks and associated topographical variation serve as templates upon which vegetation is organized over specific ranges of scales. These findings constitute an important step towards a mechanistic understanding of these patterns, and can guide upscaling and downscaling. PMID:24204610

  19. Correlation between visual function and refractive, topographic, pachymetric and aberrometric data in eyes with keratoconus

    PubMed Central

    Bayraktar Bilen, Neslihan; Hepsen, Ibrahim F.; Arce, Carlos G.

    2016-01-01

    AIM To analyze the relationship between two visual functions and refractive, topographic, pachymetric and aberrometric indicators in eyes with keratoconus. METHODS Corrected distance visual acuity (CDVA), and letter contrast sensitivity (CS) were correlated with refraction, corneal topography, pachymetry, and total corneal wavefront data prospectively in 71 eyes with keratoconus. The topographic indices assessed were simulated keratometry for the flattest and steepest meridians (SimK1 and SimK2), posterior steeper K (Ks), elevation value in best-fit sphere (BFS) maps, squared eccentricity (Є2), aspheric asymmetric index (AAI), pachymetry, thickness progression index (TPI), the amount of pachymetric decentralization (APD), and GalileiTM-keratoconus indices. RESULTS The mean CDVA (expressed as logMAR) were 0.25±0.21. The mean CS was 1.25±0.46. The spherical refraction correlated well with CDVA (r=-0.526, P<0.001). From topographic indices, SRI correlated with CS (r=-0.695), and IAI with CS (r=-0.672) (P<0.001 for all). Root mean square (RMS) was 4.3±1.81 µm, spherical aberration (SA) was -0.4±0.67 µm, vertical and horizontal coma were -2.1±1.47 and -0.4±0.72 µm. All wavefront data (except horizontal coma), AAI, Є2 and maximum BFS correlated significantly with the visual function (P≤0.001 for all). CONCLUSION In this study, CS is more affected than CDVA as a visual function. The quantity and quality of vision is significantly correlated with well-known and new topographic indices. There is not a significant correlation between visual function and pachymetric parameters. The significantly correlated indices can be used in staging keratoconus and to follow the outcome of a treatment. PMID:27588266

  20. Retinal topography maps in R: New tools for the analysis and visualization of spatial retinal data

    PubMed Central

    Cohn, Brian A.; Collin, Shaun P.; Wainwright, Peter C.; Schmitz, Lars

    2015-01-01

    Retinal topography maps are a widely used tool in vision science, neuroscience, and visual ecology, providing an informative visualization of the spatial distribution of cell densities across the retinal hemisphere. Here, we introduce Retina, an R package for computational mapping, inspection of topographic model fits, and generation of average maps. Functions in Retina take cell count data obtained from retinal wholemounts using stereology software. Accurate visualizations and comparisons between different eyes have been difficult in the past, because of deformation and incisions of retinal wholemounts. We account for these issues by incorporation of the R package Retistruct, which results in a retrodeformation of the wholemount into a hemispherical shape, similar to the original eyecup. The maps are generated by thin plate splines, after the data were transformed into a two-dimensional space with an azimuthal equidistant plot projection. Retina users can compute retinal topography maps independent of stereology software choice and assess model fits with a variety of diagnostic plots. Functionality of Retina also includes species average maps, an essential feature for interspecific analyses. The Retina package will facilitate rigorous comparative studies in visual ecology by providing a robust quantitative approach to generate retinal topography maps. PMID:26230981

  1. Topographic and Stochastic Influences on Pahoehoe Lava Lobe Emplacement

    NASA Technical Reports Server (NTRS)

    Hamilton, Christopher W.; Glaze, Lori S.; James, Mike R.; Baloga, Stephen M.

    2013-01-01

    A detailed understanding of pahoehoe emplacement is necessary for developing accurate models of flow field development, assessing hazards, and interpreting the significance of lava morphology on Earth and other planetary surfaces. Active pahoehoe lobes on Kilauea Volcano, Hawaii, were examined on 21-26 February 2006 using oblique time-series stereo-photogrammetry and differential global positioning system (DGPS) measurements. During this time, the local discharge rate for peripheral lava lobes was generally constant at 0.0061 +/- 0.0019 m3/s, but the areal coverage rate of the lobes exhibited a periodic increase every 4.13 +/- 0.64 minutes. This periodicity is attributed to the time required for the pressure within the liquid lava core to exceed the cooling induced strength of its margins. The pahoehoe flow advanced through a series of down slope and cross-slope breakouts, which began as approximately 0.2 m-thick units (i.e., toes) that coalesced and inflated to become approximately meter-thick lobes. The lobes were thickest above the lowest points of the initial topography and above shallow to reverse facing slopes, defined relative to the local flow direction. The flow path was typically controlled by high-standing topography, with the zone directly adjacent to the final lobe margin having an average relief that was a few centimeters higher than the lava inundated region. This suggests that toe-scale topography can, at least temporarily, exert strong controls on pahoehoe flow paths by impeding the lateral spreading of the lobe. Observed cycles of enhanced areal spreading and inflated lobe morphology are also explored using a model that considers the statistical likelihood of sequential breakouts from active flow margins and the effects of topographic barriers.

  2. The periepiglottic space: topographic relations and histological organisation.

    PubMed Central

    Reidenbach, M M

    1996-01-01

    Important aspects of histological organisation and topographic relations of the pre-epiglottic space are not fully understood. This region was therefore reinvestigated in plastinated serial sections of 19 human adult specimens. The cranial part of the pre-epiglottic space is homogenously filled with adipose tissue and extends around the epiglottis in a horseshoe fashion. Therefore, the term periepiglottic space (PES) is a more accurate description of this region. The cranial border of the PES is constituted by the hyoepiglottic membrane, which extends between the epiglottis and the tongue, and the hyoepiglottic ligament. The ligament consists of a cranial fibre layer anchored within the lingual muscles, and a caudal layer attached to the hyoid bone. Anterior to the lingual surface of the epiglottis, both fibre layers become apposed to form a dense collagenous mass, which may stabilise the epiglottis during deglutition. Contractions of the infrahyoid muscles will be transmitted to the thyrohyoid membrane anterior to the PES by numerous collagenous septa which originate from the membrane and radiate into the muscles. In contrast, the pre-epiglottic adipose tissue is not connected to the thyrohyoid membrane. The caudal part of the PES is subdivided by two paramedian sagittal collagenous septa. They include a medial compartment bordered by the epiglottis posteriorly and the thyroepiglottic ligament inferiorly. The two lateral subdivisions of the PES extend between the glands of the vestibular folds and towards the aryepiglottic folds, but a distinct confining collagenous layer is absent there. Posterolaterally, the PES is separated from the paraglottic space by the thyroarytenoid muscle and by a cranial extension of the fibrous sheet of the muscle. This collagenous tissue is often split into several layers and displays gaps which may facilitate the spread of malignancies. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 PMID:8655405

  3. Landsliding, topographic variables and location of cultural terraces in Slovenia

    NASA Astrophysics Data System (ADS)

    Komac, Blaž; Zorn, Matija

    2015-04-01

    For a large number of people living in hilly regions of Slovenia cultural terraces are important landscape elements. We know from previous studies that as many as half of vineyard terraces are built in areas which are highly susceptible to landslides, and a quarter in low landslide susceptibility areas. The contribution will present links between landslide susceptibility in terraced areas in Slovenia. Landslides are frequent element of cultural terraces-landscape. In Slovenia they are frequent in hilly and mountainous regions. The position of landslide areas is strongly influenced by the topography and thus indirectly by the construction of cultural terraces. They trigger during and after terraces construction when the drainage system is altered. Thus, agricultural activity leads to instability of slopes, and increases the production costs. Links between landsliding (Zorn and Komac 2004; 2008; 2009) and cultural terraces were determined using the geographic information systems. For the territory of Slovenia, we have already created landslide susceptibility map (Zorn and Komac 2004; 2008), while here we determined the correlation between landslides, topographic variables and location of cultural terraces. To achieve this aim, all areas of cultural terraces in Slovenia were digitized at the scale of 1:10,000. References Zorn, M., Komac B. 2004: Deterministic modeling of landslide and rockfall risk. Acta geographica Slovenica 44 (2), pp. 53-10. DOI: 10.3986/AGS44203 Zorn, M., Komac, B. 2008: Zemeljski plazovi v Sloveniji (Landslides in Slovenia). Georitem 8. Ljubljana: ZRC Publishing. Zorn, M., Komac, B. 2009: The importance of landsliding in a flysch geomorphic system: The example of the Gori\\vska brda Hills (W Slovenia). Zeitschrift für Geomorphologie N. F., Suppl. 56 (3), pp. 53-79. DOI: 10.1127/0372-8854/2012/S-00104

  4. A report on the Unified Lunar Control Network 2005 and lunar topographic model

    NASA Astrophysics Data System (ADS)

    Archinal, B.; Rosiek, M.; Kirk, R.; Redding, B.

    Introduction: We have finished a new general unified lunar control network and lunar topographic model based on Clementine images. This photogrammetric network solution is the largest planetary control network ever completed. It includes the determination of the 3-D positions of 272,931 points on the lunar surface and the correction of the camera angles for 43,866 Clementine images, using 546,126 tie point measurements. The solution RMS is 20 µm (= 0.9 pixels) in the image plane, with the largest residual of 6.4 pixels. We are now documenting our solution [1] and plan to release the solution results soon [2]. Previous Networks: In recent years there have been two generally accepted lunar control networks. These are the Unified Lunar Control Network (ULCN) and the Clementine Lunar Control Network (CLCN), both derived by M. Davies and T. Colvin at RAND. The original ULCN was described in the last major publication about a lunar control network [3]. Images for this network are from the Apollo, Mariner 10, and Galileo missions, and Earth-based photographs. The CLCN was derived from Clementine images and measurements on Clementine 750-nm images. The purpose of this network was to determine the geometry for the Clementine Base Map [4]. The geometry of that mosaic was used to produce the Clementine UVVIS digital image model [5] and the Near-Infrared Global Multispectral Map of the Moon from Clementine [6]. Through the extensive use of these products, they and the underlying CLCN in effect define the generally accepted current coordinate system for reporting and describing the location of lunar features. The CLCN is described in print only briefly [7]. See [8] for ULCN and CLCN files. Our efforts have merged these two networks into an improved ULCN. ULCN 2005 Features: The primary difference between our new network and the previous ones is that we solve for the radii of the control points. This avoids distortion of horizontal positions (of about 7 km average, and up to 15

  5. 12. Historic American Buildings Survey Topographic Survey of Cosmos Club, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Historic American Buildings Survey Topographic Survey of Cosmos Club, 1950, by Bernard Locroft, Civil Engineer (Showing Grounds as They Were at End of Sumner Welles Era) SITE PLAN - Townsend House, 2121 Massachusetts Avenue Northwest, Washington, District of Columbia, DC

  6. General topographic view of the Fisher School Covered Bridge, view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General topographic view of the Fisher School Covered Bridge, view looking northwest from Crab Creek Road. - Fisher School Covered Bridge, Crab Creek Road at Fiver Rivers Road, Fisher, Lincoln County, OR

  7. Topographic view of the Grande Ronde River Bridge, view looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Topographic view of the Grande Ronde River Bridge, view looking south - Grande Ronde River Bridge, Sprnning Grande Ronde River on Old Oregon Trail Highway (Oregon Route 6), La Grande, Union County, OR

  8. TOPOGRAPHIC VIEW OF MAIN STREET LOOKING NORTHEAST, WITH THE FIRST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TOPOGRAPHIC VIEW OF MAIN STREET LOOKING NORTHEAST, WITH THE FIRST BANK OF JOSEPH IN THE FOREGROUND, AND THE SCHLUER BUILDING NEAR THE CENTER OF FRAME. - Joseph Main Street, Between Joseph & Second Avenues, Joseph, Wallowa County, OR

  9. Topographic effects on denitrification in drained agricultural fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Denitrification is affected by soil moisture, while soil moisture can be affected by topography. Therefore, denitrification can be spatially correlated to topographic gradients. Three prior converted fields on the Delmarva Peninsula were sampled spatially for denitrification enzyme activity. The up...

  10. Topographic view of the Spring Creek Bridge and Collier State ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Topographic view of the Spring Creek Bridge and Collier State Park, view looking east. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  11. General topographic view of Lakeview Historic District, view looking south ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General topographic view of Lakeview Historic District, view looking south on G Street toward intersection of G and Center Streets - Lakeview Downtown Historic District, E, F & G Streets between Second Street North & First Street South, Lakeview, Lake County, OR

  12. TOPOGRAPHIC VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    TOPOGRAPHIC VIEW OF THE REX T. BARBER BRIDGE ARCH CONSTRUCTION, VIEW TO SOUTHEAST. - Rex T. Barber Veterans Memorial Bridge, Spanning Crooked River Gorge, Dalles-California Highway (US 97), Terrebonne, Deschutes County, OR

  13. Route No. 1 near west edge of Badlands Topographical Area, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Route No. 1 near west edge of Badlands Topographical Area, view to west - Route No. 1-Overton-Lake Mead Road, Between Overton Beach & Park Boundary, 6 miles south of Overton, Overton, Clark County, NV

  14. Route No. 1 through Badlands Topographical Area, view to eastnortheast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Route No. 1 through Badlands Topographical Area, view to east-northeast - Route No. 1-Overton-Lake Mead Road, Between Overton Beach & Park Boundary, 6 miles south of Overton, Overton, Clark County, NV

  15. Automated End-to-End Workflow for Precise and Geo-accurate Reconstructions using Fiducial Markers

    NASA Astrophysics Data System (ADS)

    Rumpler, M.; Daftry, S.; Tscharf, A.; Prettenthaler, R.; Hoppe, C.; Mayer, G.; Bischof, H.

    2014-08-01

    Photogrammetric computer vision systems have been well established in many scientific and commercial fields during the last decades. Recent developments in image-based 3D reconstruction systems in conjunction with the availability of affordable high quality digital consumer grade cameras have resulted in an easy way of creating visually appealing 3D models. However, many of these methods require manual steps in the processing chain and for many photogrammetric applications such as mapping, recurrent topographic surveys or architectural and archaeological 3D documentations, high accuracy in a geo-coordinate system is required which often cannot be guaranteed. Hence, in this paper we present and advocate a fully automated end-to-end workflow for precise and geoaccurate 3D reconstructions using fiducial markers. We integrate an automatic camera calibration and georeferencing method into our image-based reconstruction pipeline based on binary-coded fiducial markers as artificial, individually identifiable landmarks in the scene. Additionally, we facilitate the use of these markers in conjunction with known ground control points (GCP) in the bundle adjustment, and use an online feedback method that allows assessment of the final reconstruction quality in terms of image overlap, ground sampling distance (GSD) and completeness, and thus provides flexibility to adopt the image acquisition strategy already during image recording. An extensive set of experiments is presented which demonstrate the accuracy benefits to obtain a highly accurate and geographically aligned reconstruction with an absolute point position uncertainty of about 1.5 times the ground sampling distance.

  16. Assessing the complexity of topographic mass in complex terrains

    NASA Astrophysics Data System (ADS)

    Kurmankozhayev, Azimkhan; Nemec, Vaclav; Sarybaev, Edil

    2014-05-01

    To assess the structure of terrain more objectively it is necessary to supplement and clarify the available characteristics with a number of numerical statistical indicators and formulas that reflect the actual links between separate features of terrain. Results from analysis of traditional variability assessment methods for characteristics of georesources allow concluding that a characteristic's variability usually has oscillatory and wavelike geometric image in the form of broken, polygonal, zigzagging, polyhedral and, less frequently, regular geometric shapes, defined by deviation amplitude and period of irregularities. It is established that variability cannot be evaluated with one universal indicator since variability consists of a random and a regular component, thus it is considered reasonable to assess the characteristic's variability depending on current mining and geometrical tasks and by stages of georesources development. The recommended topographic terrain mass complexity assessment method is based on the leading concept of using properties of specific anti-entropy that, unlike regular entropy, allows accounting for changes in total number of component elements in stable populations for the topographic terrain mass. Concept of utilizing value of specific anti-entropy, widely used in information theory, is taken as an assessment criterion for integral complexity of topographic terrain mass. Modification of specific anti-entropy formula, as applied to substance of formation of the georesource development target's topographic mass integral complexity, is based on qualimetric model of its assessment. Essence of the model comes down to determining the topographic mass complexity using the topographic mass structure uncertainty measure, assessed using the quantity of heterogeneous morphometric elements contained in the topographic surface of terrain. The main basic reference value in qualimetric model of the topographic terrain mass complexity is the

  17. Airborne Topographic Mapper Calibration Procedures and Accuracy Assessment

    NASA Technical Reports Server (NTRS)

    Martin, Chreston F.; Krabill, William B.; Manizade, Serdar S.; Russell, Rob L.; Sonntag, John G.; Swift, Robert N.; Yungel, James K.

    2012-01-01

    Description of NASA Airborn Topographic Mapper (ATM) lidar calibration procedures including analysis of the accuracy and consistancy of various ATM instrument parameters and the resulting influence on topographic elevation measurements. The ATM elevations measurements from a nominal operating altitude 500 to 750 m above the ice surface was found to be: Horizontal Accuracy 74 cm, Horizontal Precision 14 cm, Vertical Accuracy 6.6 cm, Vertical Precision 3 cm.

  18. Atmospheric effects on the mapping of Martian thermal inertia and thermally derived albedo

    NASA Technical Reports Server (NTRS)

    Hayashi, Joan N.; Jakosky, Bruce M.; Haberle, Robert M.

    1995-01-01

    We examine the effects of a dusty C02 atmosphere on the thermal inertia and thermally derived albedo of Mars and we present a new map of thermal inertias. This new map was produced using a coupled surface atmosphere (CSA) model, dust opacities from Viking infrared thermal mapper (IRTM) data, and C02 columns based on topography. The CSA model thermal inertias are smaller than the 2% model thermal inertias, with the difference largest at large thermal inertia. Although the difference between the thermal inertias obtained with the two models is moderate for much of the region studied, it is largest in regions of either high dust opacity or of topographic lows, including the Viking Lander 1 site and some geologically interesting regions. The CSA model thermally derived albedos do not accurately predict the IRTM measured albedos and are very similar to the thermally derived albedos obtained with models making the 2% assumption.

  19. Morphological patterns of southeastern Mediterranean river mouths: The topographic setting of the beach as a forcing factor

    NASA Astrophysics Data System (ADS)

    Lichter, Michal; Zviely, Dov; Klein, Micha

    2010-11-01

    Israeli Mediterranean river mouths are characterized by an extremely dynamic morphology, as their channels tend to migrate hundreds of meters north and south along the shoreline. This study aims to characterize the impact of the topographic setting of the beach on the dynamic morphology of seven of these river mouths. This was achieved by morphologically mapping and monitoring the natural channel dynamics of each mouth over time; recognizing their spatial and temporal migration and avulsion patterns; describing, generalizing and classifying the different types of river mouths present on the coast; and investigating the influence of the adjacent topography on their morphology. Detailed geomorphologic mapping was achieved using remote sensing and GIS techniques, utilizing more than 300 aerial photographs taken between 1918 and 2005. This study revealed a number of typical differences in these patterns, attributed to differences in the topographic setting of the beach in the vicinity of the mouths. "Elongated strip" topography coasts demonstrate a uniform slope beach with equally spaced elevation contours, forming a narrow sandy strip between the shoreline and the back-berm. "Funnel" topography coasts exhibit a non-uniform slope with a funnel-shaped topographic depression adjacent to the river mouth. Similarities were found between the spatial and the temporal morphological patterns of river mouths flowing in each of these two topographical settings. Elongated strip mouths are deflected alongshore a barrier and demonstrate high migration distances and little temporal change. The morphology of funnel mouths was found to be highly temporally variable yet less spatially dynamic, as these mouths' channels are restricted by their funnel topography. This study concludes that the topographic setting of the beach, a constant element in the temporal scale of this study, is a primary factor influencing the morphology of the studied mouths.

  20. US Topo - a new national map deries

    USGS Publications Warehouse

    Moore, Laurence R.

    2011-01-01

    In the second half of the 20th century, the foundation of the U.S. Geological Survey's national map series was the handcrafted 7.5-minute topographic map. Times change, budgets get squeezed and currency expectations become ever more challenging. The USGS's Larry Moore, who oversees data production operations at two National Geospatial Technical Operations Centers, provides an introduction to the new US Topo quadrangle maps.

  1. Fabrication and modelling of fractal, biomimetic, micro and nano-topographical surfaces.

    PubMed

    Kyle, Daniel J T; Oikonomou, Antonios; Hill, Ernie; Vijayaraghavan, Aravind; Bayat, Ardeshir

    2016-01-01

    Natural surface topographies are often self-similar with hierarchical features at the micro and nanoscale, which may be mimicked to overcome modern tissue engineering and biomaterial design limitations. Specifically, a cell's microenvironment within the human body contains highly optimised, fractal topographical cues, which directs precise cell behaviour. However, recreating biomimetic, fractal topographies in vitro is not a trivial process and a number of fabrication methods have been proposed but often fail to precisely control the spatial resolution of features at different lengths scales and hence, to provide true biomimetic properties. Here, we propose a method of accurately reproducing the self-similar, micro and nanoscale topography of a human biological tissue into a synthetic polymer through an innovative fabrication process. The biological tissue surface was characterised using atomic force microscopy (AFM) to obtain spatial data in X, Y and Z, which was converted into a grayscale 'digital photomask'. As a result of maskless grayscale optical lithography followed by modified deep reactive ion etching and replica molding, we were able to accurately reproduce the fractal topography of acellular dermal matrix (ADM) into polydimethylsiloxane (PDMS). Characterisation using AFM at three different length scales revealed that the nano and micro-topographical features, in addition to the fractal dimension, of native ADM were reproduced in PDMS. In conclusion, it has been shown that the fractal topography of biological surfaces can be mimicked in synthetic materials using the novel fabrication process outlined, which may be applied to significantly enhance medical device biocompatibility and performance. PMID:27454401

  2. Functional and topographic concordance of right atrial neural structures inducing sinus tachycardia.

    PubMed

    Eickholt, Christian; Mischke, Karl; Schimpf, Thomas; Knackstedt, Christian; Scherer, Kira; Pauza, Danius; Marx, Nikolaus; Shin, Dong-In; Kelm, Malte; Meyer, Christian

    2013-01-01