A network-accessible service that determines travel routes and navigation information between two or more points.

least detectable difference in a measurement; in a geographic context, resolution applies to all components (time, space and attribute) according to the measurement framework. Not identical to accuracy.

a symbolic mechanism to encode data. Using computers, involves a data model, a data structure and its implementation.

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.

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).

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

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).

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

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

a programming procedure that invokes itself to subdivide a problem

[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.

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

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