GIS Dictionary

[programming] Acronym for single threaded apartment. An apartment that has only a single thread. User interface code is usually placed in an STA.

[cartography] In cartography, any material such as a Mylar sheet or film that is more durable than paper and less likely to shrink or stretch.

1 [computing] In computing, a data storage structure that operates on last in, first out (LIFO) protocol. As with a stack of dishes, the item placed on top of the … Read more

[software] An application that runs by itself, not within an ArcGIS application.

[ESRI software] Annotation that is stored in the geodatabase, consisting of geographically placed text strings that are not associated with features in the geodatabase.

A statistical measure of the spread of values from their mean, calculated as the square root of the sum of the squared deviations from the mean value, divided by the … Read more

A data classification method that finds the mean value, then places class breaks above and below the mean at intervals of either .25, .5, or 1 standard deviation until all … Read more

[spatial statistics use for geostatistics] A measure of the compactness of a spatial distribution of features around its mean center. Standard distance (or standard distance deviation) is usually represented as … Read more

[standards] The federal U.S. standard for classifying establishments by their primary type of business activity. Standard Industrial Classification codes (SIC codes) are used as an identification system in business directories, … Read more

[map projections] A line on a sphere or spheroid that has no length compression or expansion after being projected; usually a standard parallel or central meridian.

[map projections] The line of latitude in a conic or cylindrical projection in normal aspect where the projection surface touches the globe. A tangent conic or cylindrical projection has one … Read more

[cartography] A type of diagram that consists essentially of a central point from which lines radiate outward. The central point usually represents a geographic location while the length of each … Read more

[software] A ready-to-use Web application that is designed for a specific purpose, such as a store locator or a map viewer. Starter applications do not require customization before use.

1 [programming] In programming, the current data contained by an object. 2 [government] An autonomous political and administrative division of geography. The United States is composed of 50 states. 3 … Read more

[coordinate systems] A group of planar coordinate systems based on the division of the United States into more than 130 zones to minimize distortion caused by map projections. Each zone … Read more

[ESRI software] A logical organization of all the states in the geodatabase. A state tree illustrates and maintains the logical relationship between states of a versioned geodatabase.

[programming] In programming, an operation that makes changes to an object or one of its associated objects, such as removing a layer from a map.

[programming] In programming, not retaining changes between calls. A stateless object or application does not store parameters or values from the last time it was called, so it is always … Read more

[programming] An operation that does not make changes to an object, such as drawing a map.

[GPS] Determining a position on the earth by averaging the readings taken by a stationary antenna over a period of time.

[spatial statistics use for geostatistics] In geostatistics, a property of a spatial process in which all statistical properties of an attribute depend only on the relative locations of attribute values.

[linear referencing] In the pipeline industry, another name for linear referencing. Stationing allows any point along a line feature representing a pipeline to be uniquely identified by its relative position … Read more

[statistics] Ordinal, interval, or ratio data represented as a surface in which the height of each area is proportional to a numerical value.

[network analysis] A line that follows the steepest downhill direction on a surface. Paths terminate at the surface perimeter or in surface concavities or pits.

[Euclidean geometry] The solid (conical) angle subtended at the center of a sphere of radius r by a bounded region on the surface of the sphere having an area r … Read more

[map design] A map produced with a stereoscopic plotter using aerial photographs and geodetic control data.

1 [map projections] A tangent planar projection that views the earth’s surface from a point on the globe opposite the tangent point. 2 [map projections] A secant planar projection that … Read more

[photogrammetry] A stereoscope containing a micrometer for measuring the effects of parallax in a stereoscopic image.

[photogrammetry] The three-dimensional image formed where rays from points in the images of a stereoscopic pair intersect.

[photogrammetry] Two aerial photographs of the same area taken from slightly different angles that when viewed together through a stereoscope produce a three-dimensional image.

[photogrammetry] An instrument that projects a stereoscopic image from aerial photographs, converts the locations of objects and landforms on the image to x-, y-, and z-coordinates, and plots these coordinates … Read more

[photogrammetry] A binocular device that produces the impression of a three-dimensional image from two overlapping images of the same area.

[ESRI software] When editing in ArcMap, a setting that defines the minimum number of pixels the pointer must move on the screen before a selected feature is moved.

1 [modeling] A model that includes a random component. The random component can be a model variable, or it can be added to existing input data or model parameters. 2 … Read more

[ESRI software] In ArcGIS Network Analyst, a network location used to determine a route in route analysis. Users can specify multiple stops, of which two must be used to represent … Read more

[network analysis] In network analysis, the time it takes for a stop to occur, used to compute the impedance of a path or tour. For example, when a school bus … Read more

[database structures] A set of parameters that specify how data and indexes are stored in an ArcSDE database. Keywords are stored in a table in the ArcSDE database.

[analysisgeoprocessing] A type of business analysis that uses mostly data about a store or stores, rather than about customers. Examples include ring studies and analyses of equal competition areas and … Read more

A type of business analysis that assesses the potential of a site by performing simple ring or drive-time analysis.

[ESRI software] An ArcGIS Spatial Analyst function that identifies which cells belong to which source, based on closest proximity in a straight line.

[ESRI software] An ArcGIS Spatial Analyst function that identifies the azimuth direction from each cell to the nearest source.

[ESRI software] An ArcGIS Spatial Analyst function that calculates the distance in a straight line from every cell to the nearest source.

[importexport] A mode of data delivery in which objects provide data storage. Stream objects can contain any type of data in any internal structure.

[data capture] A method of digitizing in which, as the cursor is moved, points are recorded automatically at preset intervals of either distance or time.

[data capture] During stream mode digitizing, the minimum interval between vertices. Stream tolerance is measured in map units.

[importexport] A technique for transferring data, usually over the Internet, in a real-time flow as opposed to storing it in a local file first. Streaming allows large multimedia files to … Read more

[network analysis] A system of interconnecting lines and points that represent a system of roads for a given area. A street network provides the foundation for network analysis; for example, … Read more

[address matching] A form of digital mapping that links information to geographic locations and displays address locations as point features on a map.

[visualization] A display technique applied to the histogram of raster datasets, most often used to increase the visual contrast between cells.

1 [data structures] A set of coordinates that defines a group of linked line segments. 2 [programming] A sequence of letters or numbers, or both, sometimes with a fixed length.

[3D analysis] A line feature enforced in a TIN. There are two types of structure lines: hard and soft. Hard structure lines, also known as breaklines, represent interruptions in the … Read more

[analysisgeoprocessing] The geographic area treated in an analysis.

[cartography] An organized collection of predefined colors, symbols, properties of symbols, and map elements. Styles promote standardization and consistency in mapping products.

[ESRI software] The tool used to create new styles and edit existing ones. The Style Manager displays the contents of all the styles that are currently referenced by the map. … Read more

[Internet] A file or form that provides style and layout information, such as margins, fonts, and alignment, for tagged content within an XML or HTML document. Style sheets are frequently … Read more