Recent spatial_ucsb_ncgia_tr items

Linked Index to the NCGIA Technical Papers for 1988–1997

Sat, 15 Aug 2015 00:00:00 +0000

Download this index for direct links to 122 technical reports in the NCGIA Technical Papers series, published in the 1988-1997 period.

Modeling Behavior of Geographic Objects: An Experience with the Object Modeling Technique (96-11)

Thu, 13 Aug 2015 00:00:00 +0000

Behavior of geographic objects holds a critical role in spatial databases. This, along with objects’ position and space-varying attributes, form a minimal set of concepts sufficient to capture spatialpeculiarities in terms of the object-oriented rational. This paper presents the semantics and the graphical notation of a prototypical object-oriented model for the conceptual design of spatial databases: by extending the Object Model of the Object Modeling Technique to the Geographic ObjectModel, we show how the above three concepts fit naturally into any object-oriented tool. We augment this model with the constructs of spatial aggregation and spatial grouping to express the critical aspects of space-varying attributes, object boundary fuzziness and uncertainty, spatial relationships, and attribute generalization. Our proposal integrates the field- and object-based geographic views in one model. The principal idea behind this effort is the incorporation of a set of concepts into...

Selected Annotated Bibliography On Visualization of the Quality of Spatial Information (Research Initiative 7) (94-10)

Tue, 11 Aug 2015 00:00:00 +0000

This bibliography has been prepared in conjunction with NCGIA Research Initiative 7, ’Visualization of Spatial Data Quality,’ as an aid to research.Visualization of the quality of spatial data is a critical tool for the effective use of GIS, a tool which has become more urgently needed with the growing reliance on GIS, particularly in the decision making environment. Visualization tools potentially provide the GIS users with powerful insight capabilities into the nature of data.

The bibliography lists those researchers whose work falls within Initiative 7 and contains over 200 references. Issues of uncertainty, quantitative and qualitative descriptions of quality, management and quality control, and impact of quality on decision making are just a few of the areas included in this bibliography. For this bibliography to be as useful as possible, the authors have included comprehensive citations and for most entries, the abstracts are also included

GIS Laboratory Exercises: Volume 2 Technical Issues (91-14)

Mon, 10 Aug 2015 00:00:00 +0000

This set of labs is designed to illustrate and reinforce principles presented in Volume II: Technical Issues in GIS of the NCGIA Core Curriculum in GIS (units 26 to 50). Since several of these labs were originally prepared in early 1989 for the test version of the Curriculum, they have been presented to students a number of times and have undergone extensive revision. New labs have also been added to the original set. While these labs are written for a specific software and hardware configuration, they are presented as models for generic lab development and can be modified to suit other configurations and curriculum. To assist with this task, digital versions of the text are included.

Languages of Spatial Relationships (89-2)

Mon, 10 Aug 2015 00:00:00 +0000

This is a report on a workshop entitled "Languages of Spatial Relations", held in Goleta and Montecito, California, January 15-19, 1989. The meeting, and this report, represent parts of Research Initiative #2, "Languages of Spatial Relations", of the National Center for Geographic Information and Analysis (NCGIA).

The Specialist Meeting reported on in this document brought together geographers, cognitive linguists, computer scientists, engineers, and others in three days of interdisciplinary discussions on the representation of geographic space-- representation in language, in thought, and in computers. One theme of the meeting was that geographic information systems (GIS) must have at least some capabilities to deal with natural language.

This report is primarily in the form of a transcript of the meeting, reporting what was said, and focussing on discussions and debates. Appended to this report are three essays submitted after the meeting by participants. A list...

Environmental modeling with GIS: A strategy for dealing with spatial continuity (93-3)

Mon, 3 Aug 2015 00:00:00 +0000

Linking a GIS to a spatially distributed, physically-based environmental model offers many advantages. However, the implementation of such linkages is generally problematic. Many problems arise because the relationship between the reality being represented by the mathematical model and the data model used to organize the spatial data in the GIS has not been rigorously defined. In particular, while many environmental models are based on theories that assume continuity and incorporate physical fields as independent variables, current GISs can only represent continuous phenomena in a variety of discrete data models. This document develops and outlines a strategy in which field variables are used to enable modelers to work directly with the spatial data as spatially continuous phenomena.

Several outcomes from the use of this strategy are explored. Modelers can express their spatial data needs as representations of reality, rather than as elements of a GIS database, and a...

Report of the ICA Workshop on Map Generalization (97-3)

Sun, 12 Jul 2015 00:00:00 +0000

This paper reports the discussions and key findings of a three day workshop held in Gävle, Sweden immediately prior to the 18th ICA/ACI International Cartographic Conference in Stock- holm. The workshop mirrored the considerable success of the first workshop help in Barcelona in 1995 and comprised demonstrations, presentations, and parallel sessions. Thirty nine delegates came from seventeen countries comprising 20% from National Mapping Agencies (NMAs), 10% from the private sector and 70% from research institutions (Geography, Cartography, Surveying, Computer Science, Physics, Planning and Linguistics). The objective of the workshop was to hold a series of discussions focused on impediments to automated map generalization, the current state of knowledge, and progress on specific problem areas. Whenever possible, discussion pressed to define specific areas for research in the coming two years. These will be noted throughout the report.

This report is structured around...

Formalizing Behavior of Geographic Feature Types (95-7)

Sun, 12 Jul 2015 00:00:00 +0000

This paper addresses the problem of formalizing the natural-language definitions of spatial features. While the Spatial Data Transfer Standard (SDTS) supports the structural aspects of the definition of spatial features, it falls short of providing means to convey explicitly their behavior. An approach using functional algebra is developed using the example of the SDTS standard entity types “dam,” “watercourse,” and “lake,” together with the operations expressed in the natural-language definitions of these features. Formal algebraic specifications go beyond the SDTS approach, by providing precise mathematical representations of the behavior of geographic features and the interactions among related feature types. Functional specifications also help in refining the selection of attributes needed to characterize the behavior of a given feature type. An implication of the functional approach is to provide precise mathematical signatures of feature types as an alternative to natural-language...

Naive Geography (95-8)

Sun, 12 Jul 2015 00:00:00 +0000

This paper defines the notion and concepts of Naive Geography, the field of study that is concerned with formal models of the common-sense geographic world. Naive Geography is the body of knowledge that people have about the surrounding geographic world. Naive Geography is envisioned to comprise a set of theories that provide the basis for designing future Geographic Information Systems that follow human intuition and are, therefore, easily accessible to a large range of users.

Formal Models of Commonsense Geographic Worlds: Report on the Specialist Meeting of Research Initiative 21 (97-2)

Tue, 7 Jul 2015 00:00:00 +0000

This report describes the outcome of the Specialist Meeting of the NCGIA Research Initiative 21 on "Formal Models of Commonsense Geographic Worlds". The meeting was held in San Marcos, TX on October 30- November 3, 1996.

Research Initiative 21 is concerned with the development of formal models of commonsense geographic worlds. Discussions at the Specialist Meeting focused on the commonsense or naive geographic reasoning that people perform and whose outcome makes intuitive sense to most people. The Specialist Meeting brought together specialists from geographic information science, artificial intelligence, computer science, geography, developmental psychology, and behavioral science to foster discussions leading towards a better understanding of the nature of naive geographic reasoning and how better to incorporate naive geographic knowledge and reasoning into GIS.

This Report serves to document the discussions held during the meeting and, most importantly, delivers...

Spherekit: The Spatial Interpolation Toolkit (97-4)

Tue, 7 Jul 2015 00:00:00 +0000

Spherekit is a spatial interpolation software toolkit developed at NCGIA as part of Initiative 15: Multiple Roles of GIS in U.S. Global Change Research. This package features several unique capabilities and is freely distributed over the internet. Spherekit allows interpolation over continental or global scales by computing distances and orientations (among data and interpolation points) from geodesics on the surface of the globe. Conventional interpolations typically are based upon Euclidean distance in Cartesian 2-space which involve planar projections that produce distortions of some kind. In Spherekit, projections are applied only for display purposes after the interpolation has been carried out using spherical geometry. Users can select from several interpolation algorithms that have been adapted to the sphere: inverse distance weighting, thin plate splines, multiquadrics, triangulation, and kriging. Spherekit enables the user to incorporate knowledge or information about...

GIS and Society: The Social Implications of How People, Space, and Environment Are Represented in GIS- Scientific Report for the Initiative 19 Specialist Meeting (96-7)

Mon, 6 Jul 2015 00:00:00 +0000

This report is a summary of the specialist meeting of NCGIA Initiative 19: ‘The Social Implications of How People, Space, and Environment are Represented in GIS’. The meeting brought together researchers and graduate students from the US and Europe and represented a spectrum of the Geography discipline. Deliberations began in an opening plenary session where the steering committee identified three core conceptual issues: 1) epistemologies of GIS; 2) GIS, spatial data institutions, and access to information; and 3) developing alternative GISs. Subsequent small group and plenary discussions generated the following seven research focus areas:GIS 2 and virtual geographies; GIS social practice and intellectual history; Environmental justice and political ecology; GIS in the community: local knowledge and multiple realities; Data access, privacy and geodemographics; Gender and representation; and Geographic Information (and Systems) and the human dimensions of global environmental change.

Multipurpose Land Information Systems Development Bibliography: A Community-wide Commitment to the Technology and its Ultimate Applications (97-1)

Mon, 6 Jul 2015 00:00:00 +0000

This bibliography attempts to bring together literature covering the many aspects of Multipurpose Land Information Systems (MPLIS) development. Our focus on MPLIS development comes from a concern that much of GIS adoption and diffusion research focuses on a single system within an organization instead of a network of resources within the context of a larger community. We have worked to broaden the view of MPLIS development to include the processes commonly referred to as initiation, implementation, operation and maintenance.

To reflect these issues, we have attempted to develop a bibliography that includes: (a) the concept of the community-wide value of MPLIS development and the products of these systems, (b) developmental factors and techniques, (c) studies of system status, and (d) the MPLIS development process or the adoption and diffusion of innovations and related technologies. A brief explanation of each of these topics is provided along with specific examples from...

Image Registration using Multiquadric Functions, the Finite Element Method, Bivariate Mapping Polynomials and Thin Plate Spline (96-1)

Mon, 6 Jul 2015 00:00:00 +0000

In this report, three methods of image-to-image registration using control points are evaluated. We assume that ephemeris sensor and platform data are unavailable. These techniques are the polynomial method, the piecewise linear transformation and the multiquadric method. The motivation for this research is the need for more accurate geometric correction of digital remote sensing data. This is especially important for airborne scanned imagery which is characterized by greater distortions than satellite data.

The polynomial and piecewise linear methods were developed for use with satellite imagery and have remained popular due to their relative simplicity in theory and implementation. With respect to airborne data however, both of these methods have serious shortcomings. The polynomial method, a global model, is generally applied as a least-squares approximation to the control points. Mathematically it is unconstrained between points leading to undesirable excursions in...

Creation of a Comprehensive Managed Areas Spatial Database for the Conterminous United States (96-4)

Mon, 6 Jul 2015 00:00:00 +0000

In this report, the creation of a digital, spatially referenced database of managed areas in the conterminous United States is described. A Geographic Information System (GIS) was used for database compilation to provide a high degree of flexibility for updates, queries, and manipulations. As concern over the degradation of ecosystems increases, so does the need for information about the spatial location and aerial extent of managed and protected areas. Recently, focus on the ecological issues of environmental preservation has been shifting from protection of individual endangered or sensitive species to protection of entire interrelated ecosystems. To meet the demands of studies in this area, datasets for large areas of land must be created and/or compiled. Guidelines and methods for creating these types of large datasets must also be established; currently there is little information of this type available. These factors were the motivation for the creation of this Managed...

A Review of Spatial Population Database Design and Modeling (96-3)

Mon, 6 Jul 2015 00:00:00 +0000

The interest in the social and demographic aspects of environmental change and agricultural transformation has been growing steadily. At the same time, geographic information systems (GIS) have been embraced by many demographers and population geographers as “one of the most important enabling technologies in population geography” (Jones 1990). This has led to a number of studies and initiatives at various scales that explicitly focus on population dynamics in a spatial context. The material presented here is aimed at providing an overview of issues and options concerning the development of population related spatial databases that will be of use to the agricultural research community as well as in other population/environment applications. It is hoped that this paper will contribute to ongoing discussions regarding standards and guidelines for the development of spatial population databases which have been stimulated by the work of Clarke and Rhind (1992) and initiatives by CIESIN,...

Conference on Object Orientation and Navigable Databases: Report of the Meeting (96-9)

Mon, 6 Jul 2015 00:00:00 +0000

In March, 1996 the National Center for Geographic Information and Analysis (NCGIA) and the California Department of Transportation (Caltrans) jointly sponsored a conference on the application of concepts of object orientation to navigable databases. This document is the summary report of that conference. It includes a report on the conference objectives, discussion, and conclusions; a list of the participants; and background papers prepared for presentation at the conference by several of the key participants.

Algorithms for Hierarchical Spatial Reasoning (96-2)

Mon, 6 Jul 2015 00:00:00 +0000

In several applications, there is the need to reason about spatial relations using multiple local frames of reference organized in aggregation hierarchies. In this paper we deal with direction relations, a special class of spatial relations that describe order in space (e.g., north, northeast). We assume a spatial database of points and regions. Points belong to regions, which may be parts of larger regions and so on. The direction relations between points in the same region are explicitly represented. Inference mechanisms are applied to extract the relation between points in different regions and detect inconsistencies. We study two complementary types of inference. The first one derives the relation between two points that exist in different regions through chains of common points using path consistency. The second type of inference uses the relation between ancestor regions to infer the relation between the points. The paper describes algorithms for both types of inference...

Spatial Theory for the Integration of Resolution-Limited Data (96-8)

Mon, 6 Jul 2015 00:00:00 +0000

The objective of this thesis is the design of a spatial theory for GIS (consisting of representation, meta data, and transformations) that allows complete integration of data sets that differ in resolution and format. The scope is limited to a discrete view of geographic reality similar to "area-class maps", "categorical coverages", and "nominal fields". The spatial theory consists of representations of resolution-limited spatial knowledge, meta data that describe the knowledge content of representations, and transformations between representations of different type, resolution, format (raster or vector).

The spatial theory addresses the following problems: (1) What limitations does limited resolution impose on spatial knowledge that is represented in GIS? (2) How can such resolution-limited knowledge be represented in a way that keeps precise track of the contained spatial knowledge and its limitations? (3) How can the same spatial knowledge be represented in different...

Spatial Technologies, Geographic Information, and the City: Research Conference Report (96-10)

Mon, 6 Jul 2015 00:00:00 +0000

This report summarizes the results of an NCGIA-sponsored research conference "Spatial Technologies, Geographic Information, and the City" held in Baltimore, MD from September 9-11, 1996. Three group reports are presented here, summarizing participants' views on what should constitute a national research agenda in the general area of spatial technologies, geographic information, and the city.

Critical Issues in GIS-Based Educational Module Development: NCGIA’s ArcView-based Color Your World Module (96-6)

Mon, 6 Jul 2015 00:00:00 +0000

This report seeks to provide a framework for Geographic Information System (GIS) based education module development. The full potential of GIS in the K-12 classroom has not been met in part due to the limited availability of necessary support materials such as tutorials, exercises, datasets, background information on GIS and geographical data, and packaged approaches to using GIS software in learning. Now, however, GIS software is becoming easier to use as it adopts point-and-click icon and menu-based graphical user interfaces in step with broader trends in computing. These positive trends have made creating materials that support teachers and students in their use of GIS more feasible and have encouraged various groups and individuals to begin creating these support tools.

The modules investigated in this report are all based on the Environmental Systems Research Institute (ESRI) software package ArcView 2. The focus is primarily on a series of educational modules developed...

GIS Laboratory Exercises: Introduction to GIS 2nd edition (96-12)

Mon, 6 Jul 2015 00:00:00 +0000

In 1990, the NCGIA published the 1000+ page set of lecture notes, the NCGIA Core Curriculum in GIS (Goodchild and Kemp 1990). To support the lecture materials contained in the original Curriculum, in 1991 we published a pair of Technical Reports (Dodson 1991, and Veregin 1991) containing the laboratory exercises developed and taught in the Introductory GIS course in the Department of Geography at the University of California, Santa Barbara (UCSB). Since that time, the hardware, software and theory have changed dramatically and it has become necessary to revise these laboratory materials to keep up with these changes. In 1995, the Office of Instructional Development at the University of California provided funds to undertake this major revision.

This document, then, is the second edition of GIS Laboratory Exercises: Volume 1. Labs 2 to 4 in this new set of exercises draw heavily on the original materials and data, though the text and questions have been revised to be...

Geographic Information/GIS Institutionalization in the 50 States: Users and Coordinators (95-11)

Mon, 6 Jul 2015 00:00:00 +0000

This report analyzes recent information about the use and institutionalization of geographic information and related technologies such as geographic information systems (GIS), satellite imagery and the global positioning system (GI/GIS) in the 50 state governments. The devolution of federal responsibilities and activism by state governments are increasing the role of states in GI/GIS, as well as in the nation's governance in general.

An organizational chart for each state was prepared from data provided by state officials. The charts show GIS users, GI/GIS coordinators, and the organizational structure in each state government's executive branch. These charts and other information was synthesized to (1) categorize state GI/GIS users according to a classification of state government functions, and (2) determine the incidence, authorization and administrative location of statewide GI/GIS coordinators. Tables, figures and contact information for each of the states supplement...

Research Initiative 15: Multiple Roles for GIS in US Global Change Research- Report of the Second Specialist Meeting (96-5)

Mon, 6 Jul 2015 00:00:00 +0000

Initiative 15 of the NCGIA focuses on the role of GIS in global change research. Global change research links disciplines with vastly different terminologies and conceptualizations creates enormous problems, many of which are intimately associated with the issues of geographic data modeling. As a technology of geographic data, GIS is potentially the key to data integration and the successful handling of the heterogeneous databases that global change research requires.

The second specialist meeting of Initiative 15 was devoted to a discussion of advanced geographic data models for global change research. The second specialist meeting was held on Thursday, January 25 through Friday, January 26, 1996, in the El Dorado Hotel in Santa Fe. This report presents the results of that meeting; a list of the participants appears as Appendix I.

Understanding Guidance on GIS Implementation: A Comprehensive Literature Review (95-13)

Fri, 3 Jul 2015 00:00:00 +0000

This technical report reviews the literature that provides guidance on GIS implementation. It defines Guiding Literature and five Classes of publications included therein. It reviews a representative number of publications of each Class and organizes the proposals by subject. In addition, it analyses the Guiding Literature in terms of issues addressed, theoretical consistency, and theoretical diversity. The contributions of this report are two fold. First, it documents a comprehensive review of the literature on GIS implementation. It can be used as an easy-reference to the Guiding Literature as well as to proposals on one specific subject. The second basic contribution of this report is concerned not with the adequacy of the theories themselves but with their organization for practical use. The results suggest that the current theories need to be organized in a single, comprehensive guide.

Opportunities for Generalization in the Digital Chart of the World (92-2)

Fri, 3 Jul 2015 00:00:00 +0000

The Digital Chart of the World (DCW) is a database built from 1:1,000,000 scale source maps by the Defense Mapping Agency (DMA), scheduled for public release in early 1992. Nearly 200 feature types are included in 17 data layers. A layer-by-layer examination of features included in a prototype area of the DCW is accomplished for the purpose of investigating the feasibility of building a smaller scale database via generalization. Opportunities for feature generalization are identified and specific generalization operations are described. A number of the operations are performed or simulated using ARC/INFO, and the results are graphically displayed. It is found that meaningful small scale feature representation can be achieved through the application of tailored generalization operations with a significant savings in the amount of data required.

GIS and the Coastal Zone: An Annotated Bibliography (93-9)

Fri, 3 Jul 2015 00:00:00 +0000

Successful application of Geographical Information Systems (GIS) tools and concepts to the coastal zone is one of the great challenges still facing developers and users of the technology. Following a brief introduction to the role of GIS and related technologies in the coastal zone, this report consist of an annotated bibliography containing over 150 entries. All entries include keywords, and notes are provided on more than 60 of the items.

Multiple Roles for GIS in US Global Change Research: Annotated Bibliography (95-3)

Fri, 3 Jul 2015 00:00:00 +0000

This report was compiled for the National Center for Geographic Information and Analysis in conjunction with Initiative 15: Multiple Roles for GIS in US Global Change Research. The bibliography consists of an annotated collection of articles concerned with the application of GIS in global change research. These papers range from reviewed articles to conference papers. An author index is included at the end of the report to assist in finding works by particular scholars.

Designing and Implementing Strategies for Solving Large Location-Allocation Problems with Heuristic Methods (91-10)

Fri, 3 Jul 2015 00:00:00 +0000

Solution techniques for location-allocation problems usually are not a part of micro-computer based geo-processing systems. The large volumes of data to process and store and the complexity of algorithms present a barrier to implementation of these solution techniques in a micro-computer environment. Yet decision-makers need analysis systems that return solutions to location selection problems in real time. We show that processing requirements for the most accurate heuristic, location-allocation algorithm can be drastically reduced by pre-processing inter-point distance data as both candidate and demand strings and exploiting the spatial structure of location-allocation problems by updating an allocation table. Consequently, solution times increase approximately linearly with problem size. These developments allow the solution of large problems (3,000 nodes) in a microcomputer-based, interactive decision-making environment. These methods are implemented in a micro-computer system...

Intelligent Assistants for Filling Critical Gaps in GIS: A Research Program (92-4)

Fri, 3 Jul 2015 00:00:00 +0000

This research report, Intelligent Assistants for Filling Critical Gaps In GIS, was sponsored by Southern California Edison Company (SCE), Geographic Designs Inc., and the NCGIA to identify a research program that provides: an analysis of critical gaps in current geographic information systems (GIS) that impede their use for spatial decision support; a research agenda adapting expert system and other related technologies to fill these gaps; and a discussion of emerging technologies for supporting spatial decision makers. The research agenda presented here focuses on applying artificial intelligence techniques of expert and related systems to create Intelligent Assistant systems to support the GIS user with capabilities for coping with the critical ’gaps.

Spatial Data Analysis and GIS: Interfacing GIS and Econometric Software (93-7)

Fri, 3 Jul 2015 00:00:00 +0000

Discusses the interface between a GIS and spatial data analysis and further focuses on three aspects of spatial econometric analysis: (1) spatial weights matrix (2) spatial dependence in regression models (3) the estimation of spatial regression models. Includes software routines for extracting spatial weights matrices from common GIS packages (Arc/Info, packages GAUSS, LIMDEP, RATS, SHAZAM, and SPLUS.

The NCGIA Guide to Laboratory Materials - 1993 (93-10)

Fri, 3 Jul 2015 00:00:00 +0000

This document is an updated version of NCGIA Technical Paper 91-20: The NCGIA Guide to GIS Laboratory Materials - 1991. This 1993 update includes approximately 40 pages of new or updated material, plus an appendix which contains a set of eight full-text GIS exercises. The document is a compendium of information pertaining to GIS laboratory education. Our objective is to provide resources which facilitate the establishment of a GIS laboratory curriculum. These resources include references to student exercises produced by the NCGIA, vendors, and other institutions; as well as aids for the creation of new exercises, including ideas for topics and sources of appropriate data.

Testing Technology Transfer Hypotheses in GIS Environments Using a Case Study Approach (93-8)

Fri, 3 Jul 2015 00:00:00 +0000

In late 1990 and early 1991, a methodological framework was developed for testing technology transfer hypotheses within GIS operational environments. The paper reporting this work was titled "Case Study Research Methods for Geographic Information Systems" (Onsrud, Pinto, and Azad 1992). This report gathers together (1) the original foundation paper used as the basis for the case study research project, (2) the call for participation that includes a listing of the thirty hypotheses for which "control conditions" were sought in each case study, and (3) reports from two of the case studies. The two case studies incorporated into this report were selected for inclusion because they most closely adhered to the methodology presented in the original Onsrud, Pinto, and Azad paper and they provided constructive criticism of the methodology. Most case work seen to date in the GIS community has been directed at deriving theory. The intent of this project was to spur work in which pre-derived...

Gap Analysis of the Southwestern California Region (94-4)

Fri, 3 Jul 2015 00:00:00 +0000

Numerous efforts are underway by public and private groups to assess the status of biodiversity in the state. Most are being conducted at local to subregional scales, and many are focused on species or communities of special concern. Currently lacking is an overview of the protection status of species and communities both statewide and in the western U.S. as a whole. This report describes a geographic information system (GIS) based Gap Analysis of biodiversity in the Southwestern California Ecoregion. The project is part of an ongoing effort by many groups, including the USFWS, the California Department of Fish and Game (CDF&G), Department of Forestry and Fire Protection (CDF&FP), The Nature Conservancy (TNC) and others to provide this regional overview by mapping the distributions of plant community types and vertebrate species habitats and relating these distributions to existing patterns of land ownership and land management. The work at UCSB is supported by the National...

A Research Agenda for the NCGIA Renewal 1993-1996 (92-7)

Fri, 3 Jul 2015 00:00:00 +0000

This document presents a revised and updated research agenda for geographic information and analysis, including references and linkages to NCGIA research initiatives.

The first 42 months of the NCGIA have demonstrated that a multi-institutional, multi-disciplinary center for the advancement of fundamental geographic and GIS research can function effectively. The new research plan builds on the previous one, but also reflects the advancement in our thinking. The five research areas listed in the original solicitation from the National Science Foundation, often referred to as "the five bullets", are herein replaced by three general research areas: spatial representation; spatial analysis; and spatial informatics. This new framework serves as the common base from which individual research efforts can be selected and planned, and into which they are integrated. Research at the NCGIA will continue to focus on the data-intensive modeling of spatial phenomena and spatial processes,...

GIS Teaching Facilities: Six Case Studies on the Acquisition and Management of Laboratories (91-21)

Fri, 3 Jul 2015 00:00:00 +0000

Many colleges and universities around the world have begun to offer courses in GIS (geographic information systems), but many do not have access to adequate facilities for laboratory sections of these courses. The purpose of this NCGIA technical report is to provide examples of the successful establishment of computer labs for GIS instruction. Since every situation is unique, we have identified six colleges and universities with GIS teaching laboratories which together represent a broad spectrum of experience. One person at each site was asked to write a report detailing the process they went through when attempting to set up their lab, the present configuration and operating concerns presented by their labs, and the manner in which the lab is used for GIS teaching. Each individual received a list of topics as a guide to writing, but for the most part the reports reflect personal style and the major concerns presented by each situation.

Integrating Normative Location Models into GIS: Problems and Prospects with the p-median Model (94-5)

Fri, 3 Jul 2015 00:00:00 +0000

There has been considerable interest in the development of analysis techniques for Geographical Information Systems (GIS). This includes such normative spatial models as vehicle routing models, districting and turfing models for dividing up land into territories for schools, sales/service, and voting, and location models for identifying sites or patterns of sites to provide service accessibility. The GIS system may provide a unique data base for application and analysis. This paper discusses several problems associated with the integration of a normative location model into a GIS. A number of specifics associated with the p-median model are given. These include: demand zone definition, facility site definition, and solution algorithm selection and development. Within the context of selecting a solution process, we show that such a selection is not necessarily an easy one to make. We demonstrate that the best such solution technique may have some potential drawbacks in application....

Multiple Topological Representations (91-17)

Fri, 3 Jul 2015 00:00:00 +0000

Humans use multiple mental models of the world to reason efficiently at different levels of abstraction. Current geographic information systems (GIS) normally use only a single model or representation of the world. If only a single level of abstraction is supported, the utility of the system is limited. Future GIS should support multiple representations at different levels of abstraction, so that adequate levels of abstraction can be found for a large range of scales. Queries that require little detail can then be processed as efficiently as those which require much detail.

This paper proposes an approach to supporting multiple levels of abstraction in a GIS through multiple topological representations (MTR). The representations are linked by hierarchical relations between elementary spatial building blocks called cells. We introduce largest homogeneous cells (LHC’s) to guarantee the hierarchical structure of these links. LHC’s can easilybe modelled in topological representations...

NCGIA Research Initiative 7 Visualization of Spatial Data Quality: Scientific Report for the Specialist Meeting (91-26)

Fri, 3 Jul 2015 00:00:00 +0000

This report is a summary of the Specialist meeting for NCGIA Research Initiative 7 entitled "Visualization of Spatial Data Quality" . It presents initial discussions on the role and utility of visualization for understanding and analyzing information about the quality of GIS data. The impetus for the initiative is based on rapid changes in spatial information system technology and a desire to see the technology used more effectively. Technology currently allows us to process and display large volumes of information very quickly. Effective use of this information for analysis and decision making presupposes that the information is correct or reasonably reliable. Information on the quality of data is essential for effective use of GIS data: it affects the fitness of use of data for a particular application, the credibility of data representation and interpretation, and the evaluation of decision alternatives. The credibility of spatial decision support using GIS may indeed depend...

Integration of Remote Sensing and Geographic Information Systems: Report of the Specialist Meeting (91-16)

Fri, 3 Jul 2015 00:00:00 +0000

This report summarizes the planning meetings and preliminary work that led to the first Specialist Meeting for Initiative 12, Integration of Remote Sensing and Geographic Information Systems. It also provides a detailed synopsis of the highlights of the specialist meeting held in December 1990 at the EROS Data Center, Sioux Falls, South Dakota. The majority of materials presented are included here as well as the research priorities which were developed by the attendees at the working sessions. Each of the five topical areas is represented by the paper presented by the coordinator of the area, as well as viewgraphs and comments from the discussants where available. We also include a list of the attendees at the end of this document.

Collaborative Spatial Decision-Making: Scientific Report for the Initiative 17 Specialist Meeting (95-14)

Fri, 3 Jul 2015 00:00:00 +0000

This is a report on the first meeting of the seventeenth NCGIA research initiative, entitled “Collaborative Spatial Decision-Making.” This meeting, held in Santa Barbara between September 16th and 19th, 1995, was attended by representatives of the NCGIA, university faculty members from North America and Europe, and representatives of US companies. The contents of this report are compiled from the notes of the organizers and student rapporteurs, materials prepared during the meeting and the personal notes of several of the participants.

Direction Relations and Two-Dimensional Range Queries: Optimization Techniques (95-9)

Fri, 3 Jul 2015 00:00:00 +0000

Despite the attention that direction relations, such as east, southeast etc., have attracted in several domains related to Spatial Databases and Geographic Information Systems (GIS), little work has been done on their formalization and efficient processing. In this paper we define direction relations between two-dimensional objects in different levels of qualitative resolution and we show how these relations can be efficiently retrieved in existing DBMSs using B- , KDB- and R- tree-based data structures. Since query processing involving direction relations maps into range queries in two- dimensional space, our work essentially studies optimization techniques for 2D ranges. We test the efficiency of alternative indexing methods through extensive experimentation and we present analytical models that estimate their performance. The analytical estimates are proved to be very close to the actual results and can be used by spatial query optimizers in order to decide the appropriate...

Connecting ARC/INFO and SNACTor Project Report (91-11)

Fri, 3 Jul 2015 00:00:00 +0000

This report describes an interface between ARC/INFO, a geographic information management system, and SNACTor, the SNePS acting component. It also shows a small example interaction that demonstrates how ARC/INFO and SNACTor can interact using the new interface, and how more sophisticated future applications can make use of its functionality. The interface was designed and implemented during a two-month research project carried out in Summer, 1990 at the State University of New York at Buffalo.

Framework Datasets for the NSDI (95-1)

Fri, 3 Jul 2015 00:00:00 +0000

There appears to be a growing agreement among the users of geographic and land information systems that common sets of geographic data on which users could build to their own particular data needs would promote greater data sharing among the various players in the geographic information system (GIS) community (NRC 1994). Such common data sets, referred to as "core" or "framework" data sets, could be collected by designated government agencies or by participating members of the private sector and added to the public domain, via the National Spatial Data Infrastructure (NSDI), for the use of any and all interested parties. There are many existing digital geographic data sets that enjoy great popularity among various members of the GIS community. However, there appears to be no clear consensus of which geographic data sets would be of greatest value to these government agencies and private businesses. This report is concerned with the identification and prioritization of framework...

Secondary Education Project: Color Your World- An Exploration With ArcView 2.0 (95-5)

Fri, 3 Jul 2015 00:00:00 +0000

Color Your World is the latest addition to the set of resources developed by the Secondary Education Project of the National Center for Geographic Information and Analysis (NCGIA.) The Secondary Education Project has been supporting efforts to bring the great educational potential of geographic information systems (GIS) to the K-12 schools. Color Your World is an interactive Geographic Information System (GIS) based computer game that exposes students to fundamental and essential geographic information that is necessary for understanding not only geography but politics, economics, demography, and other interesting information about our world. The game is designed so that students can play it over and over again and continue to learn from the experience of simply playing the game. Just as writing cannot be accomplished without the mastery of letters, spelling, words, and grammar; geographical communication requires that one have a basic working knowledge of the names, locations,...

Two Papers on Triangulated Surface Modeling (95-2)

Fri, 3 Jul 2015 00:00:00 +0000

The first paper describes the implementation of three methods for fitting surfaces: linear, quintic and stochastic. It uses qualitative (visual) and quantitative (statistical) criteria to compare the three approaches. The digital terrain model is based on a triangular irregular network (TIN) structure and the comparison is performed using a mathematically defined function and real data obtained from a raster digital elevation model (DEM) from a United States Geological Survey (USGS) elevation file.

The second paper addresses the problem of constructing Triangular Irregular Network (TIN) models from irregularly distributed samples with constrained lines. The implementation of an incremental constrained Delaunay triangulation is described and compared qualitatively with the unconstrained Delaunay triangulation.

A Comparison of Strategies for Data Storage Reduction in Location-Allocation Problems (95-4)

Fri, 3 Jul 2015 00:00:00 +0000

Many solution techniques for discrete location-allocation problems make use of a sorted distance strings data structure in order to speed processing time. The primary drawback to distance strings is that in a standard computer architecture they require approximately 50% additional memory storage in comparison to a standard distance matrix. To reduce the additional memory requirements of distance strings, researchers such as Hillsman [1980] and Densham and Rushton [1992a] have proposed a strategy for cutting the distance strings to include only sets of relatively close neighbor nodes. This has become an important implementation issue for solving relatively large location- allocation problems. In fact, the new Location-Allocation module of the ARC/Info GIS system uses a distance string structure and a string cutoff option to save storage and processing time. The danger in employing only partial distance strings is that if too few distance entries are stored in the distance strings,...

NCGIA Research Initiative 8 (Formalizing Cartographic Knowledge): Scientific Report for the Specialist Meeting (95-15)

Fri, 3 Jul 2015 00:00:00 +0000

This report is a summary of the Specialist meeting for NCGIA Research Initiative 8 entitled "Formalizing Cartographic Knowledge". The Specialist Meeting was held in Buffalo New York, 24-27 October 1993 to discuss knowledge representation and formalization issues relating to automation of cartographic processes. The four research topics given high priority are to formalize the language of cartographic elements and to standardize definitions of GIS processing operations, to implement formalized mechanisms to evaluate mapping system design, to impose more rigorous structure on the process of eliciting cartographic knowledge, and to embed cartographic knowledge into spatial data models and spatial data processing models.

An Annotated Bibliography on Human Computer Interaction for GIS (91-15)

Fri, 3 Jul 2015 00:00:00 +0000

This document is a collection of references gathered by the instructor and students in a course on human computer interfaces for GIS offered by the Surveying Engineering Department at the University of Maine in the Fall of 1990. The class searched widely through the available literature to find any information that would be relevant to the design and implementation of user interfaces for GIS. The search was broad and inclusive rather than focused and systematic. We attempted to find literature with which the GIS community would be unlikely to be acquainted. The result is a somewhat scatological entrance to tile literature. It is neither systematic, nor comprehensive. Its best use might be to stimulate further search through unfamiliar literature.

Multiple Roles for GIS in US Global Change Research (NCGIA Research Initiative 15): Report of the First Specialist Meeting (95-10)

Fri, 3 Jul 2015 00:00:00 +0000

This report presents the findings of the first specialist meeting of NCGIA Research Initiative 15, held at the Upham Hotel in Santa Barbara, California, March 9-11, 1995. Research Initiative 15 focuses on the role of GIS in global change research. The importance of GIS can only increase as global change research becomes more data- and computation-intensive, as it moves from studies of single processes to integrated modeling, as it struggles to link human and physical processes, and as it places more emphasis on policy formulation and decision-making. The report is in four sections. Following an introductory section describing the NCGIA and the objectives of Research Initiative 15, the second section presents a synthesis of findings from the first specialist meeting. This is followed by more specific reports from each of the three working groups formed at the meeting. A list of participants and the position papers written prior to the meeting by the participants form the appendices.

The Global Demography Project (95-6)

Fri, 3 Jul 2015 00:00:00 +0000

Demographic information is usually provided on a national basis. But we know that countries are ephemeral phenomena. As an alternate scheme one might use ecological zones rather than nation states. But there is no agreement as to what these zones should be. By way of contrast global environmental studies using satellites as collection devices yield results indexed by latitude and longitude. Thus it makes sense to assemble the terrestrial arrangement of people in a compatible manner. This alternative is explored here, using latitude/longitude quadrilaterals as bins for population information. This data format also has considerable advantage for analytical studies. The report is in three parts. Part I gives the motivation and several possible approaches. Ways of achieving the objective include, among others, simple centroid sorts, interpolation, or gridding of polygons. In Part 11 the results to date of putting world boundary coordinates together with estimates of the number of...

On Information Modeling To Support Interoperable Spatial Databases (95-12)

Fri, 3 Jul 2015 00:00:00 +0000

A major research topic in geographic databases is that of interoperability, i.e., the capability to access transparently remote data and processes in an open environment. This paper addresses the issue of information modeling for interoperating geographic databases. In particular, it deals with the topic of exchanging semantics at the information systems context. Our proposal is based on the peculiarities of spatial data, namely field- and object-based views of space and spatial relationships, that are critical for the representation of information in an interoperable environment. A generic Geographic Data Model that encapsulates these semantics and makes their interchange among remote systems possible and without ambiguities, is proposed. We show with an example how this model supports interaction among heterogeneous spatial application domains. This research effort is based on (a) the requirements expressed by the OpenGIS community, (b) results from modeling “classical” interoperable...

GIS, Cartography, and the Information Society: An Annotated Bibliography (93-12)