National Center for Geographic Information and Analysis

This short narrative introduces the Core Curriculum in GIS and provides a historical overview of the Core Curriculum Project, including the later Core Curriculum in GIScience and Core Curriculum for Technical Programs. Appended to this description is an original pamphlet advertising the Core Curriculum in GIS.

This unit introduces the Triangulated Irregular Network (TIN) model for representing a surface as an alternative to the regular raster of a digital elevation model (DEM). The TIN concept is described, and several alternative methods for creating a TIN—including point selection and triangulation—are presented. The unit concludes with sections considering storage of TINs and several algorithms on TINs.

This unit examines the common methods of data input. It describes the hardware and methods used for digitizing and scanning spatial information from maps and photographs, and it discusses conversion of data between digital formats and associated issues of projection, scale and resolution.

This unit reviews a few simple algorithms that are fundamental to the topics of later units, which describe how complex operations are constructed. It begins with a definition of algorithm and heuristic, then walks through an example of the steps required to assess whether two simple lines intersect. Special cases where this method fails are noted, and heuristics are presented for assessing whether complex lines intersect.

This unit outlines fundamental concepts in database systems and their integration with GIS, including advantages of a database approach, views of a database, database management systems (DBMS), and alternative database models. Three models—hierarchical, network and relational—are discussed in greater detail.

This is the final unit in a six-unit series on the design, purchase and implementation of a GIS. This unit focuses on the benefit/cost analysis: what it is, why it is useful and how to approach it. It discusses how costs, both one-time and recurring, may be determined and how benefits of a GIS may be quantified or otherwise identified. A method for comparing costs and benefits is outlined and illustrated through an example from the Department of Natural Resources, State of Washington.

This unit considers one of the most important technical issues in GIS—data accuracy. It examines several aspects of data accuracy included in the National Standard for Digital Cartographic Data: positional accuracy, attribute accuracy, logical consistency, completeness and lineage.

This unit begins a six-part section that reviews the spectrum of different applications of GIS. It characterizes the core groups of GIS activity in terms of three categories: (1) mature technologies that interact with GIS sharing its technology and creating data for it; (2) management and decision-making groups; and (3) science and research activities at universities and government labs. This unit focuses on the first category, exploring GIS applications in cartography, surveying and engineering, and remote sensing. Science and research activities are addressed, as well.

This unit begins the module on coordinate systems and geocoding, which includes units 26–29.  It introduces plane coordinate systems—Cartesian and polar—and the global coordinate system of latitude and longitude. Technical issues of storing coordinates in a database and propagation of errors are discussed.

This unit concludes the module on coordinate systems and geocoding. Several important practical issues are raised here that will be important particularly for those who will be working with economic and demographic databases. The difference between continuous and discrete georeferencing is described before focusing on five of the most common methods of discrete georeferencing: address matching, postal code systems, the US Public Land Survey System, the GEOLOC grid and census systems. Examples illustrate each, and the unit concludes with a discussion of issues associated with discrete georeferencing.