Base map - A GIS data layer of reference information, such as topography, road network, or streams, to which all other layers are referenced geometrically (source: Illinois Institute of Technology
Clip - The process of extracting a portion of a coverage or map from a larger coverage, much like a cookie cutter. (source: University of Minnesota Extension)
Dataset - Any collection of related data, usually grouped or stored together. (source: ESRI)
Geographic Information Systems (GIS) - Acronym for geographic information system. An integrated collection of computer software and data used to view and manage information about geographic places, analyze spatial relationships, and model spatial processes. A GIS provides a framework for gathering and organizing spatial data and related information so that it can be displayed and analyzed. (source: ESRI)
Global Positioning Systems (GPS) - System of satellites in orbit that allow their use by a receiver to decode time signals and convert the signals from several satellites to a position on the earth's surface (source: Illinois Institute of Technology)
Interpolation - The process of estimating the value of an unsampled data point for a given x,y,z location based on the values of surrounding sampled data points. (source: University of Minnesota Extension)
LANDSAT - The generic name for a series of natural resource scanning satellites launched by the United States beginning in 1972. (source: University of Minnesota Extension)
Layer - A logical separation of mapped information representing a theme (e.g., roads, soils, vegetative cover). Layers are registered to each other by control points and the common coordinate system of the database. (source: University of Minnesota Extension)
Macro - A set of instructions written in a high-level programming language that manipulate the commands in a GIS to perform specific predefined tasks or processes. Macros typically provide enhanced user access both to limited portions of an extensive GIS database as well as to certain GIS analysis tools or procedures. Sometimes called "shells." (source: University of Minnesota Extension)
Metadata - Information that describes the content, quality, condition, origin, and other characteristics of data or other pieces of information. Metadata for spatial data may describe and document its subject matter; how, when, where, and by whom the data was collected; availability and distribution information; its projection, scale, resolution, and accuracy; and its reliability with regard to some standard. Metadata consists of properties and documentation. Properties are derived from the data source (for example, the coordinate system and projection of the data), while documentation is entered by a person (for example, keywords used to describe the data). (source: ESRI)
Model - An abstraction of reality used to represent objects, processes, or events. OR A set of rules and procedures for representing a phenomenon or predicting an outcome. (source: ESRI)
Polygon - A two-dimensional figure with three or more sides intersecting at a like number of points. It is defined or bounded by a closed line or arc and has attributes that describe its geographic features. (source: University of Minnesota Extension)
Raster data model - A spatial data model that defines space as an array of equally sized cells arranged in rows and columns, and composed of single or multiple bands. Each cell contains an attribute value and location coordinates. Unlike a vector structure, which stores coordinates explicitly, raster coordinates are contained in the ordering of the matrix. Groups of cells that share the same value represent the same type of geographic feature. (source: ESRI)
Remote sensing - The act of detection and/or identification of an object, series of objects, or landscape without having the sensor in direct contact with the object. Often results in the generation of image data. (source: University of Minnesota Extension)
Spatial data - Data that can be linked to locations in geographic space, usually via features on a map (source: Illinois Institute of Technology)
Vector data model - A coordinate-based data model that represents geographic features as points, lines, and polygons. Each point feature is represented as a single coordinate pair, while line and polygon features are represented as ordered lists of vertices. Attributes are associated with each vector feature, as opposed to a raster data model, which associates attributes with grid cells. (source: ESRI)
