Seamless Online Distribution of Amundsen Multibeam Data

Since 2003, all underway multibeam and sub-bottom data from the Canadian Coast Guard Ship Amundsen has been posted online within approximately six months of the end of each cruise. A custom interface allowing the user to access 15\u27 latitude by 30\u27 longitude mapsheets was implemented in 2006, allowing the user to download the bathymetric and backscatter data at 10 metre resolution. While this interface matched the underlying data management scheme implemented at the University of New Brunswick, the zoom and pan capability was at a fixed scale with limited contextual data. In the past few years, with the introduction of web-based geographic information systems (GIS) (e.g. Google Maps, Yahoo Maps, Bing Maps), there have been thousands of maps published online. These online GIS programs are a suitable platform to display the seven years of Amundsen coverage within the context of the GIS-served satellite imagery and allow the user to freely browse all data in a familiar interface. The challenge, however, for serving up third party data through these map engines is to efficiently cope with the multiple zoom levels and changing resolutions. Custom tiling software was developed to take all the raw data from the seven years of Amundsen (and others\u27) multibeam coverage and convert it into multiple scale resolution images suitable for interpretation by Google Maps. The images were stored in a pyramid structure utilizing Google\u27s map projection and uniquely named to reflect their georeferencing and resolution. This image pyramid is then accessed by Google Maps according to the user\u27s current zoom level to optimize visualization. This multi-resolution data is served up on demand from the University of New Brunswick for dynamic overlay on Google\u27s satellite data. This web interface allows any interested parties to easily view multibeam and sub-bottom data from the Pacific Ocean through the Canadian Arctic Archipelago and into the Atlantic Ocean. The broad overview helps to understand regional trends and then focus on areas of interest at high resolutions to see particular features. The web interface also provides a link to the 15\u27 by 30\u27 mapsheet model with full source traceability

Segmentation And Spatial Depth Ridge Detection Of Unorganized Point Cloud Data

Visual 3D data are of interest to a number of fields: medical professionals, game designers, graphic designers, and (in the interest of this paper) ichthyologists interested in the taxonomy of fish. Since the release of the Kinect for the Microsoft XBox, game designers have been interested in using the 3D data returned by the device to understand human movement and translate that movement into an interface with which to interact with game systems. In the medical field, researchers must use computer vision tools to navigate through the data found in CT scans and MRI scans. These tools must segment images into the parts that are relevant to researchers and account for noise related to the scanning process all while ignoring other types of noise such as foreign elements in the body that might indicate signs of illness. 3D point cloud data represents some unique challenges. Consider an object scanned with a laser scanner. The scanner returns the surface points of the object, but nothing more. Using the tool Qhull, a researcher can quickly compute the convex hull of an object (which is an interesting challenge in itself), but the convex hull (obviously) leaves out any description of an object\u27s concave features. Several algorithms have been proposed to illustrate an object\u27s complete features based on unorganized 3D point cloud data as accurately as possible, most notably Boissonnat\u27s tetrahedral culling algorithm and The Power Crust algorithm. We introduce a new approach to the area partitioning problem that takes into consideration these algorithms\u27 strengths and weaknesses. In this paper we propose a methodology for approximating a shape\u27s solid geometry using the unorganized 3D point cloud data of that shape primarily by utilizing localized principal component analysis information. Our model accounts for three comissues that arise in the scanning of 3D objects: noise in surface points, poorly sampled surface area, and narrow corners. We explore each of these areas of concern and outline our approach to each. Our technique uses a growing algorithm that labels points as it progresses and uses those labels with a simple priority queue. We found that our approach works especially well for approximating surfaces under the condition where a local surface is poorly sampled (i.e a significant hole is present in the point cloud). We then turn to study the medial axis of a shape for the purposes of `unfolding\u27 that structure. Our approach uses a ridge formulation based on the spatial depth statistic to create the medial axis. We conclude the paper with visual results of our technique

Ecological processes regulating geographic distributions of Plethodon salamanders in the Southern Appalachian Mountains

Understanding how dispersal, adaptation to environmental characteristics, and interactions among species set the limits to species geographic distributions is one of the primary goals of biogeography. Evolutionary history of a species allows for a species to be adapted to a particular environment and is thought to have the greatest influence on where, geographically, a species can exist. However, often the species distribution is much smaller than its potential range based solely on environmental characteristics alone, and both local and regional ecological processes are responsible for this range restriction. For instance, the ability to disperse to suitable habitat and interspecific associations also factor in to the capability of a species to access and successfully colonize regions outside of its distribution. In this study, I assess patterns in trophic morphology, environmental characteristics, and spatially-explicit population models to assess the geographic distribution of Plethodon teyahalee. I find that the mechanisms regulating this species` distribution varies geographically, and that it is a combination of both environmental characteristics and interspecific competition which regulate this species` geographic range limits in this group. Further, this research also demonstrates that local processes, such as interspecific competition, can be important in understanding regional patterns such as species geographic distributions

Design, Operations, and Safety of High-Speed Approach Rural Roundabouts

High-speed approach rural roundabouts have been found to reduce overall crashes by 71% and injury crashes by 87% and have become an effective tool used by public agencies to improve safety and capacity at rural intersections. In this presentation we will discuss critical design features for effective implementation, including alignment on approach, deflection, splitter islands, lighting, signing, curbing, diameter, design vehicle, and landscaping. Before-and-after results involving safety, operations, and public acceptance will be highlighted at specific US roundabouts

Deployment of Mobile Broadband Service in the United States

Broadband deployment in the United States is expanding rapidly but unevenly. Using new FCC census data on wireline and wireless broadband providers, we study mobile broadband provision within the United States. Although rural areas lag non-rural areas in the availability of residential access to both mobile and fixed broadband, mobile broadband is at least partially filling in geographical gaps in fixed-line broadband coverage. Multiple regression results indicate that population density and growth, and the fraction of blacks, Hispanics, and youth in an area are positive predictors of the number of mobile broadband providers. The fraction of Native Americans, Asians, and senior citizens in an area are negative predictors. Income is positively associated with the number of providers, with largest effects in rural areas. Finally, even after controlling for population density and income, rural areas continue to be associated with a lower number of providers