List of Important Concepts

for Geography 460

Geographic Information System

Levels of measurement

nominal, ordinal, interval, ratio
Extra issues: cyclical; extensive versus derived
Additions to the list: counts, absolute

Reference Systems

Time
Space (coordinate systems, geoid, datum, etc.)
Attribute

fixed, controlled, measured

Measurement Frameworks

Controlled by classification (attribute)

Isolated object methods: spatial object, isopleth
Connected coverages: network framework, categorical coverage

Controlled by space

Methods of grid encoding
Point methods
Area methods

Control by relationships: pairs, TINs

Relationship between levels of measurement/ measurement framework and ArcView commands

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Representation

Raster
Vector
Spaghetti (isolated objects)
Topological data structure
Attribute tables

Procedures for overlay combination

Rules: dominance, contributory, interaction
Overlay logic and applications: change detection, testing, suitability

Neighborhood operations

Geometric rules: buffers, setbacks, larger neighborhoods
Attribute rules: dominance, contributory, interaction

Comprehensive operations

Iterative operators: viewshed, accumulated cost surfaces, drainage
More comprehenisve operations: location/allocation, network, statistics?

Surfaces

Properties
Topology
Representation: contours; DEM; TIN

Transformations

Geometric component: neighborhhoods - within measurement framework, beyond
Attribute combination rules: dominance, contributory, interaction

Digitizing methods

role of topological structure in quality control

Data quality and fitness for use

Error
Components of data quality

Lineage
Positional Accuracy, Attribute Accuracy,
Logical Consistency, Completeness

Metadata

A practical implementation of these concepts

ArcMap
Spatial Analyst
Layers, Tables, Views, Operations