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No Title Sort descending Definition
1 Tabular data

[data storage] Descriptive information, usually alphanumeric, that is stored in rows and columns in a database and can be linked to spatial data.

2 Thematic Layer

[data structure] A thematic layer is a distinct spatial entity in a data layer. They are usually delineated as points, lines and polygons.

3 Topography

[software] Topography is the study and mapping of Earth’s features including land surfaces, relief (relative positions and elevations) and the position of natural (water features, physiographic features, etc.) and constructed features (boundaries, cities, parks, landmarks, transportation, buildings, etc.)

4 Topology

[editing] Topology is a set rules that dictates the spatial properties of point, line and area features such as connectivity, adjacency and contiguity.

5 Transportation

Transportation data are used to model the geographic locations, interconnectedness, and characteristics of the transportation system within the United States. The transportation system includes both physical and nonphysical components representing all modes of travel that allow the movement of goods and people between locations.


Source: OMB Circular A–16: Appendix E (2002) Category: NSDI Data Themes (NDT)

6 Traverse

[surveying] A traverse is a set of survey stations along spanning a survey. Traverses are closed when they return to their starting point.

7 Triangular Irregular Networks (TIN)

[data structure] TINs are vector-based models depicting three-dimensional elevation surface terrains.