a spatial data model based upon a regular tessellation of a surface into pixels or grid cells.

[data structure] A raster is a data model used in GIS which are usually regularly-size rectangular or square shaped grid cells arranged in rows in columns.

The process of converting an image made up of cells into one described by lines and polygons.

a level of measurement that includes both extensive and derived measurements. The numerical values of the measurement have a meaningful zero reference and a fixed unit of measure

Refers generally to systems that respond (almost) immediately or synchronously to external events.

[data structure] A record in an attribute table row that specifies an instance of an entity. It represents a spatial feature in the dataset in a one-to-one relationship.

a programming procedure that invokes itself to subdivide a problem

Geometric reference surface embedded in 3D Euclidean space formed by an ellipse that is rotated about a main axis.

the process of connecting a spatial representation to a broader spatial reference system.

a data model based on set theory. Each set has elements that can be uniquely defined by a primary key. A table (relation) stores all records for a set. Each record in a table has the same columns for attribute values. Relationships between tables are constructed by storing the key to a record in the other table (a foreign key).

Closeness of the relative positions of features in a dataset to their respective relative positions accepted as or being true.

Remote sensing is the science of deriving information about the earth's land and water areas from images acquired at a distance. It usually relies upon measurement of electromagnetic energy reflected or emitted from the features of interest (Campbell 1987).

Create an electronic or hardcopy representation, particularly of an outline font. When an outline font is rendered, it assumes a fixed size and shear angle on the screen, raster, or hardcopy to which it is rendered.