GIS Dictionary

1 [remote sensing] The arrangement of a set of satellites in space. 2 [GPS] All the satellites visible to a GPS receiver at one time. 3 [GPS] The set of … Read more

1 [graphics map display] The intensity or purity of a color; the perceived amount of white in a hue relative to its brightness, or how free it is of gray … Read more

[computing] The ability to grow in size or complexity without showing negative effects.

[ESRI software] In Survey Analyst, used to define measurement units based on a common standard.

1 [cartography] The ratio or relationship between a distance or area on a map and the corresponding distance or area on the ground, commonly expressed as a fraction or ratio. … Read more

1 [cartography] The ratio or relationship between a distance or area on a map and the corresponding distance or area on the ground, commonly expressed as a fraction or ratio. … Read more

[symbology] A map element used to graphically represent the scale of a map. A scale bar is typically a line marked like a ruler in units proportional to the map’s … Read more

1 [cartography] The reciprocal of the ratio used to specify scale on a map. For example, if the scale of a map is given as 1:50,000, the scale factor is … Read more

[map display] The scales at which a layer is visible on a map. Scale ranges are commonly used to prevent detailed layers from displaying at small scales (zoomed out) and … Read more

1 [data capture] A device that captures a print or hard-copy image, such as a text document or map, and records the information in digital format. 2 [remote sensing] A … Read more

The process of capturing data from hard-copy maps or images in digital format using a device called a scanner.

[statistics] A chart in which each data point is marked against perpendicular x- and y-axes. Scatter charts are frequently used in analysis to find data trends.

[ESRI software] In 3D Analyst, a document containing 3D data that can be viewed in perspective.

1 [computing] The structure or design of a database or database object, such as a table, view, index, stored procedure, or trigger. In a relational database, the schema defines the … Read more

[ESRI software] During geodatabase editing, the process of applying schema changes from a replica to the relative replica in a replica pair. Examples of schema changes include adding or dropping … Read more

[database structures] In ArcGIS 9.1 and previous versions, a type of checkout that creates the schema of the data being checked out in the checkout geodatabase but does not copy … Read more

[software] Acronym for Service Control Manager. An administrative tool that enables the creation and modification of system services. It effectively serves as the runtime environment for COM.

[computing] A file, created by either a software user or an operating system, that holds temporary data or results during an operation. When the operation is complete, the file is … Read more

[ESRI software] A path to a container for file-based geographic data that can be set in the Environment Settings dialog box or at the command line, into which all automatically … Read more

1 [programming] A set of computing instructions, usually stored in a file and interpreted at run time. 2 [ESRI software] In ArcView 3.x, one of the five types of documents … Read more

1 [quality control] Checking the accuracy of data before it is converted into a different format. 2 [quality control] Improving the appearance of data by closing open polygons, fixing overshoots … Read more

[ESRI software] A collection of Smart Data Compression (SDC) feature classes sharing attribute information with different geometries. An SDC dataset is stored in a set of related files and contains … Read more

[ESRI software] A highly compressed, read-only data structure that can store spatial geometry (points, lines, and polygons), and attribute data. The SDC structure supports geocoding, routing, and most spatial operations. … Read more

[ESRI software] The account used to administer ArcSDE. The SDE user requires certain advanced database privileges to configure and manage ArcSDE geodatabases and ArcSDE services.

[ESRI software] A system environment variable that defines the location where ArcSDE software is installed.

[ESRI software] A program run by a database administrator during ArcSDE installation or upgrade. The sdesetup program creates or upgrades the ArcSDE system tables. It is named differently for different … Read more

[data sharing] Acronym for spatial data infrastructure. A framework of technologies, policies, standards, and human resources necessary to acquire, process, store, distribute, and improve the use of geospatial data across … Read more

[programming] Acronym for software development kit. A set of code libraries and related tools used to develop platform-specific applications.

[standards] Acronym for Spatial Data Transfer Standard. A data exchange format for transferring different databases between dissimilar computing systems, preserving meaning and minimizing the amount of external information needed to … Read more

[ESRI software] In ArcGIS Image Server, a polygon that defines the mosaic boundary of the raster dataset used in an image service. Overlapping raster datasets can be blended along the … Read more

[analysisgeoprocessing] The maximum distance in coverage units a feature can be from the current point for consideration as the closest feature. The default is the width or height of the … Read more

[network analysis] In network analysis, the threshold distance used to find the closest network element to a network location.

[spatial statistics use for geostatistics] In spatial interpolation, a polygon that forms a subset of data around the prediction location. Only data within the searching neighborhood is used for interpolation.

[software] In software licensing, the number of simultaneous instances of software that can be used at one time. Most often, seats represent software users at individual computers. Seats may, however, … Read more

[mathematics] A straight line that intersects a curve or surface at two or more points.

A projection whose surface intersects the surface of a globe. A secant conic or cylindrical projection, for example, is recessed into a globe, intersecting it at two circles. At the … Read more

[database structures] The second level of guidelines for designing table and data structures in a relational database. The second-normal-form guideline incorporates the guidelines of first normal form; in addition, it … Read more

[spatial statistics use for geostatistics] In geostatistics, the assumption that a set of data comes from a random process with a constant mean, and spatial covariance that depends only on … Read more

[geocoding] All material used as reference data in an address locator beyond the primary reference data. Secondary reference data can consist of an Alternate Name table or a Place-Name Alias … Read more

1 [network analysis] The arcs or portions of arcs used to define a route. 2 [cadastral and land records] One thirty-sixth of a township, bounded by parallels and meridians, equal … Read more

[ESRI software] The attribute table for the section feature class in a coverage, containing the route number and arc number to which the section belongs, the starting and ending positions … Read more

[ESRI software] In ArcGIS, a geometric element from which paths are constructed. A segment consists of a start point, an endpoint, and a function that describes a straight line or … Read more

[data analysis] To choose from a number or group of features or records; to create a separate set or subset.

[ESRI software] Layers from which features can be selected in ArcMap with the interactive selection tools. Selectable layers can be chosen using the Set Selectable Layers command in the Selection … Read more

[ESRI software] A subset of features in a layer, or records in a table, that is chosen by the software user.

[ESRI software] A subset of the features in a layer or records in a table. ArcMap provides several ways to select features and records graphically or according to their attribute … Read more

[ESRI software] In an ArcMap editing session, a small “x” located in the center of selected features. The selection anchor is used in the snapping environment, or when rotating, moving, … Read more

[ESRI software] An ArcInfo Workstation file that stores the specifications of the selection criteria to be applied against specific coverages and INFO tables. It does not store the actual selected … Read more

[GPS] The intentional degradation by the U.S. Department of Defense of the GPS signal for civilian receivers, which could cause errors in position of up to 100 meters. Selective availability … Read more

[data models] The definition of the meaning of concepts within a data model by their relationships to other concepts.

[geodesy] The equatorial radius of a spheroid, often referred to as “a.”

[spatial statistics use for geostatistics] The variogram divided by two.

One’s perception of the essential character of a place in which one resides or has resided, stemming from a personal response to the environment. Sense of place usually refers to … Read more

[statistics] Analysis designed to test the robustness of model and analytical results to ensure that small changes in model parameters or data structure do not exhibit large changes in the … Read more

[remote sensing] An electronic device for detecting energy, whether emitted or radiated, and converting it into a signal that can be recorded and displayed as numbers or as an image.

[statistics] Analysis based on a sample of an unfixed size in which testing continues only until a trend is observed with a predefined level of certainty.

[ESRI software] The isolation level in a database management system (DBMS) that offers the highest degree of isolation from concurrent transactions. All reads in the transaction only see data committed … Read more

[data conversion] A method of data conversion in which data is encoded as a sequence, stored in a file, memory buffer, or other medium, and transmitted across a network connection. … Read more

[data conversion] A file that stores serialized data.

1 [hardware] A computer that manages shared resources, such as disks, printers, and databases, on a network. 2 [software] Software that provides services or functionality to client software. For example, … Read more

[software] The operating system account that the server object manager service runs as. The server account is specified by the GIS server postinstallation utility.

[programming] In ArcGIS, the environment on the GIS server within which a service or server object and its associated objects are running. A server context runs within a server container … Read more

[data storage] A location on a file system used by a GIS server to retrieve map caches and write different types of output.

[programming] In ArcGIS, an object that manages and serves a GIS resource, such as a map or a locator. A server object is a high-level object that simplifies the programming … Read more

[programming] In ArcGIS, a condition that describes whether multiple instances of a service can run within the same process. Services with high isolation run dedicated processes, whereas services with low … Read more

[software] Products that can be used on one enterprise server machine. Each server product requires a unique registration number used to generate the authorization file. The Software Authorization Wizard is … Read more

[geolocating] An address locator in which processing is done on one computer with the results accessible to other computers. Server-side address locators consist of services available over the Internet, via … Read more

1 [computing] A persistent software process that provides data or computing resources for client applications. 2 [ESRI software] In ArcWeb Services, any Web service or geographic data. 3 [computing] In … Read more

[ESRI software] In ArcGIS Network Analyst, a type of network analysis for determining the region that encompasses all accessible streets (streets that lie within a specified impedance). For example, the … Read more

[ESRI software] The currency for ArcGIS Online. Service credits are consumed when using certain functions, for example spatial analysis, routing, or geocoding. Also referred to as ‘credits’.

[software] A software program that receives service requests from clients, processes data, and serves it back to the client.

[ESRI software] In ArcGIS Image Server, a table defining links to multiple raster datasets and some service-specific attributes, including display range. A service table is stored as part of the … Read more

[programming] A Java platform technology for extending Web servers that provides a component-based, platform-independent method for building Web-based applications.

[programming] In ArcIMS, the default connector used to connect the ArcIMS Application Server to a Web server.

[programming] A Java platform technology that interfaces with a Web server and hosts servlets. Servlet engines provide a common application programming interface (API) that servlets use to build Web applications.

[programming] The process by which a Web application maintains information across a sequence of requests by the same client to the same Web application.

A handheld navigational instrument that measures, from its point of observation, the angle between a celestial body and the horizon or between two objects. The angle is measured on a … Read more

[programming] Acronym for Standard Generalized Markup Language. A markup language with a predefined vocabulary and structure. SGML is used to structure information in a DTD, or Document Type Definition format, … Read more

[Internet] Acronym for Secure Hash Algorithm v1. A Federal Information Processing Standards (FIPS) method for encoding sensitive information before sending the information over the Internet. The method jumbles data, such … Read more

A raster image that shows changes in elevation using light and shadows on terrain from a given angle and altitude of the sun.

Graphic patterns such as cross hatching, lines, or color or grayscale tones that distinguish one area from another on a map.

[programming] An application that uses the session state management capabilities of a Web server to maintain application state and makes stateless use of server objects. Shallowly stateful applications can use … Read more

[data models] The characteristic appearance or visible form of a geographic object as represented on a map. A GIS uses points, lines, and polygons to represent the shapes of geographic … Read more

[ESRI software] A vector data storage format for storing the location, shape, and attributes of geographic features. A shapefile is stored in a set of related files and contains one … Read more

[data models] A boundary common to two features. For example, in a parcel database, adjacent parcels share a boundary. Another example is a parcel that shares a boundary on one … Read more

[ESRI software] Data layers, services, maps, applications, and so on that are available to more than one user.

[ESRI software] Data layers, services, maps, applications, and so on that are available to more than one user.

[data models] A vertex common to multiple features. For example, in a parcel database, adjacent parcels share a vertex at the common corner.

[symbology] A map symbol that serves as a route marker. Shields come in many varieties, but the most common shields in the United States are for interstate highways, U.S. routes, … Read more

[spatial statistics use for geostatistics] In a spatial model, fine-scale variation that is usually modeled as spatially-dependent random variation.

1 [network analysis] The best route or the route of least impedance between two or more points, taking into account connectivity and travel restrictions such as one-way streets and rush-hour … Read more

[software] A complete application that demonstrates a solution for a specific need.

[geocoding] An adjustable value that dictates how far away from either the left or right side of a line feature an address location should be placed. A side offset prevents … Read more

[ESRI software] In Survey Analyst, used to compute a coordinate that is not a part of the main traverse course sequence.

1 [remote sensing] Information conveyed via an electric current or electromagnetic wave. 2 [physics] The modulation of an electric current, electromagnetic wave, or other type of flow in order to … Read more

[remote sensing] The ratio of the information content of a signal to its noninformation content (noise).

[statistics] In statistical testing, the probability of an incorrect rejection of the null hypotheses.

[spatial statistics use for geostatistics] A parameter of a variogram or semivariogram model that represents a value that the variogram tends toward when distances become large. Under second-order stationarity, variables … Read more

[ESRI software] In a geodatabase, a line feature that corresponds to a single network element in the logical network.

[data models] A point, line, or polygon that is not part of a geometric network and is not an annotation feature, dimension feature, or custom object.