Design and Implementation of a Model,Web-based,GIS-Enabled Cancer Atlas

Abstract

The design and development of a highly interactive web-based, GIS-enabled atlas is reported. The atlas is a prototype, designed as a model for implementation of atlases to support government cancer-control activities. This model integrates symbolisation and design principles from print cartography, interaction strategies from exploratory geovisualisation, and web-map/web-feature service advances from GIS. The atlas has been implemented using a client-server architecture. It makes use of two open-source GIS tools, PostGIS (as the system database) and GeoServer (to connect the database to the client mapping application). The client mapping application has been built in Macromedia Flash. The entire client-server architecture is described, then direct primary emphasis is focused on the client mapping application. For this component of the system, the interface design strategy is detailed, the approach taken to implement this strategy in Flash is documented, and the mechanisms developed to build dynamic links from the client to the underlying database through the server are outlined. Features of the atlas are presented through a prototypical use scenario for a target user.     

Cognitive and Usability Issues in Geovisualization

We provide a research agenda for the International Cartographic Association's Commission on Visualization and Virtual Environment Working Group on Cognitive and Usability Issues in Geovisualization. Developments in hardware and software have led to (and will continue to stimulate) numerous novel methods for visualizing geospatial data. It is our belief that these novel methods will be of little use if they are not developed within a theoretical cognitive framework and iteratively tested using usability engineering principles. We argue that cognitive and usability issues should be considered in the context of six major research themes: 1) geospatial virtual environments (GeoVEs); 2) dynamic representations (including animated and interactive maps); 3) metaphors and schemata in user interface design; 4) individual and group differences; 5) collaborative geovisualization; and 6) evaluating the effectiveness of geovisualization methods. A key point underlying our use of theoretical cognitive principles is that traditional cognitive theory for static two-dimensional maps may not be applicable to interactive three-dimensional immersive GeoVEs and dynamic representations—thus new cognitive theory may need to be developed. Usability engineering extends beyond the traditional cartographic practice of "user testing" by evaluating software effectiveness throughout a lifecycle (including design, development, and deployment). Applying usability engineering to geovisualization, however, may be problematic because of the novelty of geovisualization and the associated difficulty of defining the nature of users and their tasks. Tackling the research themes is likely to require an interdisciplinary effort involving geographic information scientists, cognitive scientists, usability engineers, computer scientists, and others.     

Multivariate Analysis and Geovisualization with an Integrated Geographic Knowledge Discovery Approach

The discovery, interpretation, and presentation of multivariate spatial patterns are important for scientific understanding of complex geographic problems. This research integrates computational, visual, and cartographic methods together to detect and visualize multivariate spatial patterns. The integrated approach is able to: (1) perform multivariate analysis, dimensional reduction, and data reduction (summarizing a large number of input data items in a moderate number of clusters) with the Self-Organizing Map (SOM); (2) encode the SOM result with a systematically designed color scheme; (3) visualize the multivariate patterns with a modified Parallel Coordinate Plot (PCP) display and a geographic map (GeoMap); and (4) support human interactions to explore and examine patterns. The research shows that such "mixed initiative" methods (computational and visual) can mitigate each other's weakness and collaboratively discover complex patterns in large geographic datasets, in an effective and efficient way.     

Inset Mapper: A Software Tool In Island Cartography

Island cartography deals with special cartographic problems confronted in the portrayal of island regions and demands the use of specially developed software tools. One of the most commonly faced problems is the need of inset map creation for very small islands, and sometimes isolated ones, that must be displayed in the main map. This paper presents the methodology followed for the development of the Inset Mapper (IM) Software toolbox, describes the toolbox, and showcases its ability to create inset maps in Island regions. The IM software tool provides a useful cartographic tool for assisting the selection of the most appropriate position and scale of the inset map in an Island region.     

Visualizing Geospatial Information Uncertainty: What We Know and What We Need to Know

Developing reliable methods for representing and managing information uncertainty remains a persistent and relevant challenge to GIScience. Information uncertainty is an intricate idea, and recent examinations of this concept have generated many perspectives on its representation and visualization, with perspectives emerging from a wide range of disciplines and application contexts. In this paper, we review and assess progress toward visual tools and methods to help analysts manage and understand information uncertainty. Specifically, we report on efforts to conceptualize uncertainty, decision making with uncertainty, frameworks for representing uncertainty, visual representation and user control of displays of information uncertainty, and evaluative efforts to assess the use and usability of visual displays of uncertainty. We conclude by identifying seven key research challenges in visualizing information uncertainty, particularly as it applies to decision making and analysis.     

Virtual City Design Based on Urban Image Theory

Abstract

This paper aims to evaluate what effect applying residents' urban image to virtual city design (a real time virtual model of an actual city) has on wayfinding performance during 'flying-based' navigation mode. Two experiments were conducted to compare two virtual city designs using the virtual model of Tel Aviv city. One design included highlighted urban elements from the residents' urban image, while in the second design no highlighted elements were included.

The experiments proved that using the elements of the residents' urban image in a virtual city design enhances the performance of all participants in the wayfinding tasks, and especially those with a low level of spatial knowledge. Analysis of the trajectory patterns and the verbal reports of the participants during navigation showed that the urban image design facilitates a more intensive use of a position-based strategy, in addition to the path-integration wayfinding strategy, which was found to be dominant in the virtual model without the highlighted urban image elements. On the basis of these findings we propose principles for designing virtual cities from a perspective of wayfinding.     

Geocollaborative Soil Boundary Mapping in an Experiential GIS Environment

Soil maps are an important and integral component of national geospatial data infrastructures. The creation of these maps involves a geovisualization exercise whereby soil scientists develop cognitive models that correlate observable landscape features to soil occurrence. This is traditionally an analog process, cognitively demanding, time consuming, and invariably non-collaborative. A new geovirtual soil mapping technique is proposed in this paper in the form of an innovative Experiential GIS (EGIS) environment. This immersive environment enables soil maps to be constructed through experiencing and interacting with spatial data through immersion in 3D geovirtual scenes. The system outlined integrates GIS, immersive geovisualization, and robust geodatabase capabilities. Four soil scientists with extensive soil mapping experience ranging from 5 to over 20 years are concurrently immersed in the same 3D geovirtual landscape which more closely mirrors the way in which we view the world around us. The soil scientists are immersed within the 3D scene where they are essentially freed from the laws of physics, and may roam anywhere across the landscape as if in a virtual helicopter. The landscape is draped with any combination of orthoimagery and GIS-derived data allowing soil scientists to interpret, digitally delineate, and attribute soil boundaries. Exploiting the EGIS technology while maintaining the centrality of the soil scientist in soil interpretation and soil map production, promises considerable resource efficiencies than those achieved in traditional soil survey. The paper lays out the nature of this potential paradigm shift in soil mapping. The results of using this technology to construct soil geographic knowledge are also discussed in terms of soil map detail, cost efficiencies, time effectiveness, system usability, geocollaborative soil mapping advantages, and the reduced cognitive workload on practicing soil scientists.     

Constraints as Means of Controlling Usage of Geovirtual Environments

In this paper a concept for controlling the usage of geovirtual environments by means of constraints is developed. Constraints serve to improve the usability of geovirtual environments by guarding the navigation and interaction processes of users. In addition, they facilitate the implementation of Digital Rights Management for geovirtual environments. The presented approach distinguishes spatial constraints, structural constraints, and redistribution constraints. Several types of spatial constraints have been identified for navigation in geovirtual environments. To demonstrate their applications, this paper reports on using constraints in virtual 3D city models.     

Visualizing Distributions from Multi-Return Lidar Data to Understand Forest Structure

Abstract

Spatially distributed probability density functions (pdfs) are becoming more relevant to Earth scientists and ecologists because of stochastic models and new sensors that provide numerous realizations or data points per unit area. One source of these data is from multi-return airborne lidar, a type of laser that records multiple returns for each pulse of light sent towards the ground. Data from multi-return lidar is a vital tool in helping us understand the structure of forest canopies over large extents. This paper presents visualization tools to allow scientists to rapidly explore, interpret and discover characteristic distributions within the entire spatial field. The major contribution of this work is a paradigm shift which allows ecologists to think of and analyse their data in terms of full distributions, not just summary statistics. The tools allow scientists to depart from traditional parametric statistical analyses and to associate multimodal distribution characteristics to forest structures. Information on the modality and shape of distributions, previously ignored, can now be visualized as well. Examples are given using data from High Island, southeast Alaska.     

Cartographic Design and Production in the Internet Era: The Example of Tourist Web Maps

Abstract

Some, but not all, branches of the tourist industry make heavy use of maps. The industry has discovered the marketing potential of the Internet but in many cases has not yet fully exploited the extra potential of web maps compared to the traditional paper maps. Web maps can up-to-date tourist information very well but they have to be carefully designed to take account of the limitations of the medium. To be most effective, web maps should be basically simple and convey sufficient information interactively, on request. The map and symbol design should convey intuitively where and how this interaction can take place. This paper summarizes the typical faults found in tourist web map design and provides suggestions on good design practice.