Key Terms and Definitions
- Precise and Accurate: The property indicating that the area for a parcel polygon in GIS may be
considered both accurate and precise.
- Points: In a vector data model, points utilize coordinate pairs to represent curvature within a line.
- Spatial Analysis: GIS differentiates itself from traditional surveying and mapping by introducing spatial
analysis techniques.
- Datum: A mathematical model that relates to real-world features and defines how spatial data is
mapped and understood.
- Georeferencing: The method employed to align an unreferenced dataset with one that has known
spatial reference information.
- Control Points: Commonly used locations that aid in aligning and referencing two datasets accurately.
- Index Contours: In contour mapping, these are darker lines that represent specific contour levels.
- Contours: Imaginary lines on a map that depict areas with constant elevation.
- Maps: Visual representations that inherently suggest patterns in the phenomena they depict, serving
as a fundamental use of mapping.
- Sampling Locations, Streams, Wetland Areas: When creating a web map, these layers should generally
be placed in an order from larger geographic context to smaller specifics.