S-GIS Glossary,

This glossary is a sub-set of one developed by the Urban and Regional Information
Systems Association (URISA)

Scale

• Relationship between the dimensions of a feature on a map and the geograhic features they represent on the earth,
• Commonly expressed as a fraction. For example map scale of 1:24000 means that one unit of measure on the map equals 24000 of the same unit on the earth (1 inch would equal 24000 inches = 2000 feet).
• A calibrated line, as on a map or an architectural plan, indicating such a proportion.
• Description of how length in the real world is related to length on a map. This can be portrayed in a variety of ways including a representational fraction.

Scroll
To cause a spatial display to move vertically or horizontally across the screen so that a new line of text or graphics appears at one edge of the screen for each line that moves off the opposite edge.


Spatial analysis

• Methods used to explore the spatial relationships between features both real and theoretical.
• Process of extracting or creating new information about a set of geographic features; techniques to determine the distribution of a spatial feature(s); and the relationships between two or more features, the location of, proximity to, and orientation of these features in space.
• Study of the locations and shapes of geographic features and the relationships between them.

Spatial Data

• One of the three kinds of Data (spatial, textural and image). Spatial data is categorized according to the following feature types:
• Zero dimensional features: Primitive Points; topological Node.
• One dimensional features: Primitive Lines, Strings (multiple nonbranching lines), arcs (mathematically defined curve; topological Links, chains, and rings.
• Two dimensional features: Polygons defining enclosed areas, Pixels, and Grid Cells.

Spatial Query
Function that allows a user to find, display, and/or isolate attributes records linked to map features located within a defined area of interest - window, circle, polygon or trace. Also see “query”.


SQL
Accronym for Structured Query Language, a computer industry-standard syntax language for querying and manipulating most relational database management systems (RDBMS). Commands can be embedded within a programming language to interface to a database or used interactively.


State Plane Coordinate System
System of X,Y coordinates defined by the USGS for each state. Locations are based on the distance from an origin point defined for each state.

Survey Control Network

• Graphically defined lattice work of precise control points (monuments) and traverse alignments reconciled to those monuments, serving as a framework for referencing the position of all map features in the spatial database, thereby assuring appropriate precision standards.
• Points with a given horizontal position and surface elevation.
• Used to determine unknown horizontal positions and elevations of locations elsewhere in the active portion of the spatial database.