GIS Dictionary

[data capture] Data that is displayed immediately, as it is collected. Real-time data is often used for navigation or tracking.

[ESRI software] The time mode in ArcGIS Tracking Analyst in which data is automatically displayed on the map after being added.

[spatial analysis] The process of taking input cell values and replacing them with new output cell values. Reclassification is often used to simplify or change the interpretation of raster data … Read more

[database structures] In concurrency management, to merge all modified data in the current database edit session with a second version of the data.

1 [database structures] A set of related data fields, often a row in a database, containing all the attribute values for a single feature. For example, in an address database, … Read more

[data conversion] The process of applying a mathematical transformation to an image so that the result is a planimetric image.

1 [mathematics] Characterized by straight lines, usually parallel to orthogonal axes. 2 [map design] A map or image whose horizontal and vertical scales are identical.

[programming] The process by which server instances in a pool are replaced by new instances of services. Recycling allows services that have become unusable to be destroyed and replaced with … Read more

[government] The process of revising the boundaries of administrative, legislative, or election districts.

[ESRI software] In Survey Analyst, occurs when the number of observed measurements is greater than the number of computed coordinates in a measurement network.

[programming] A pointer to an object, interface, or other item allocated in memory. COM objects keep a running total of the references to themselves via the IUnknown interface methods AddRef … Read more

[geocoding] In geocoding, material containing the location and address information of specific features. Reference data consists of the spatial representation of the data and the related attribute table.

[ESRI software] In ArcGIS, a spatial data layer that a geocoding service uses to perform address geocoding. A reference data source can be any point, line, or polygon feature class … Read more

[ESRI software] In ArcGIS, a spatial data layer that a geocoding service uses to perform address geocoding. A reference data source can be any point, line, or polygon feature class … Read more

[geodesy] Any datum, plane, or surface from which other quantities are measured.

[geodesy] Any datum, plane, or surface from which other quantities are measured.

[geodesy] An ellipsoid associated with a geodetic reference system or geodetic datum.

[map design] A map designed to show where geographic features are in relation to each other.

[ESRI software] In Survey Analyst, a point with known coordinates, used as input to a computation.

[symbology] The scale at which symbols appear on a digital page at their true size, specified in page units. As the extent is changed, text and symbols will change scale … Read more

[coordinate systems] A method for identifying positions on the globe. This is often constructed with a grid that either refers to the earth’s latitude and longitude (graticule), or a planar … Read more

[ESRI software] In ArcView 3.x, a theme used to perform geocoding. A reference theme can be any point, line, or polygon theme that contains the necessary address fields. Each address … Read more

[ESRI software] In Survey Analyst, occurs when a copy of a coordinate from a different project is added to the survey point for exclusive use in your project. When this … Read more

[ESRI software] A DBMS-defined restriction that ensures that foreign key values in the rows in the child table always have matching primary key values in the parent table.

[data quality] A mechanism for ensuring that data remains accurate and consistent as a database changes. When changes are made to a table related to another table by a common … Read more

[physics] The proportion of incident radiant energy that is reflected by a surface. Reflectance varies according to the wavelengths of the incident radiant energy and the color and composition of … Read more

[non-ESRI software] A utility, part of the Windows operating system, that allows you to view and edit the system registry.

1 [geography] In geography, an area usually distinguished by common cultural or physical characteristics, such as Southern California, Western Europe, or Southeast Asia. 2 [data models] A set of contiguous … Read more

1 [data editing] To align two or more maps or images so that equivalent geographic coordinates coincide. 2 [geolocating] To link map coordinates to ground control points. 3 [software] In … Read more

[ESRI software] A three-letter, nine-digit number (ABC123456789, for example) that authenticates software with ESRI. Every single use and server product, including their extensions or options, has a unique registration number.

[computing] Stores information about system configuration for a Windows machine. COM uses the registry extensively, storing details of COM components including ProgIDs and ClassIDs, file location of the binary code, … Read more

[software] A file containing information in Windows Registry format. Double-clicking a .reg file in Windows will enter the information in the file into the system registry. Often used to register … Read more

[statistics] A statistical method for evaluating the relationship between a single dependent variable and one or more independent variables thought to influence the dependent variable. Regression is used to predict … Read more

[statistics] A value associated with each independent variable in a regression equation, representing the strength and type of relationship the independent variable has to the dependent variable. For example, fire … Read more

[statistics] The mathematical formula applied to independent variables to best predict the dependent variable being modeled. The notation in regression equations is always Y for the dependent variable and X … Read more

[software] A Windows utility that registers a DLL or similar component library to a system registry. A DLL and its components must be registered before it can be used.

[programming] In programming, to reinstantiate an object and its state from persisted storage.

[geocoding] Handling unmatched addresses through fine-tuning the geocoding process. After a table of addresses are matched the first time, unmatched addresses can be reviewed or edited. Reject processing attempts to … Read more

[database structures] An operation that establishes a temporary connection between records in two tables using a key common to both.

[ESRI software] An ArcToolbox utility used to build, modify, save, and delete connections (relates) between tables. Saved connections can be reactivated in future ArcToolbox sessions.

[database structures] A data structure in which collections of tables are logically associated with each other by shared fields.

1 [ESRI software] In ArcGIS Spatial Analyst, an operator that evaluates specific relational conditions. If a condition is TRUE, the output is assigned a value of 1. If the condition … Read more

[database structures] An association or link between two objects in a database. Relationships can exist between spatial objects (features), between nonspatial objects (rows in a table), or between spatial and … Read more

[database structures] An item in the geodatabase that stores information about a relationship. A relationship class is visible as an item in the ArcCatalog tree or contents view.

[accuracy] A measure of positional consistency between a data point and other, near data points. Relative accuracy compares the scaled distance of objects on a map with the same measured … Read more

[navigation] A bearing measured relative to a vessel or aircraft’s heading.

[map projections] Coordinates identifying the position of a point with respect to another point.

[computing] In computing, the location of a computer file given in relation to the current working directory.

[ESRI software] In geodatabase editing, the other replica in a replica pair of parent and child. The relative replica to a child replica is the parent replica, and vice versa.

[cartography] A map element that contains a simplified view of the sources used to compile a map.

[cartography] Elevations and depressions of the earth’s surface, including those of the ocean floor. Relief can be represented on maps by contours, shading, hypsometric tints, digital terrain modeling, or spot … Read more

[geocoding] The process of regeocoding a feature or features in a geocoded feature class.

[remote sensing] Collecting and interpreting information about the environment and the surface of the earth from a distance, primarily by sensing radiation that is naturally emitted or reflected by the … Read more

[remote sensing] Imagery acquired from satellites and aircraft, including panchromatic, radar, microwave, and multispectral satellite imagery.

[graphics computing] A mechanism that defines how data appears when displayed. For example, the hillshade renderer for raster data in ArcMap calculates and applies shading based on existing data values … Read more

[graphics computing] The process of drawing to a display; the conversion of the geometry, coloring, texturing, lighting, and other characteristics of an object into a display image.

[ESRI software] In 3D Analyst, a tab on the Layer Properties dialog box that allows users to control whether or not a layer is displayed during scene navigation, how it … Read more

[ESRI software] The isolation level in a database management system (DBMS) that ensures that when the same rows are read multiple times during the course of a transaction, the returned … Read more

[ESRI software] In geodatabase editing, the portion of the data in a geodatabase that is copied from a source geodatabase to a destination geodatabase during the replication process. The replica … Read more

[ESRI software] In geodatabase editing, each combination child and parent replica.

[ESRI software] An XML file that describes schema differences between the data in a replica and its relative replica.

[ESRI software] A workspace document file that describes the schema of the data in a replica.

[ESRI software] In geodatabase editing, the version being replicated during the replication process. For all replica types, the replica version for a parent replica is the version the user was … Read more

[ESRI software] A means of copying and distributing data from one database to local, remote, or mobile users and then synchronizing between these databases for consistency.

1 [ESRI software] In ArcGIS, a database that contains the schema information needed to create a geodatabase from a UML model created using a CASE tool. 2 [ESRI software] In … Read more

1 [cartography] A method of illustrating data so it can be viewed and understood. In cartography, representation is used to depict likenesses of real-world features in such a way that … Read more

[ESRI software] In ArcGIS, a specialized geometry vertex that controls the phases of certain geometric effects in a representation rule.

[ESRI software] In ArcGIS, the combination of symbology and any geometric effects that together define the appearance of features sharing a common representation rule ID.

[cartography] The ratio of a distance on a map to the equivalent distance measured in the same units on the ground. A scale of 1:50,000 means that one inch on … Read more

[mathematics] The process of interpolating new cell values when transforming rasters to a new coordinate space or cell size.

[statistics] In a regression model, the difference between the observed Y value and the predicted Y value; the unexplained portion of the dependent variable. Predicted values rarely match observed values … Read more

1 [cartography] The detail with which a map depicts the location and shape of geographic features. The larger the map scale, the higher the possible resolution. As scale decreases, resolution … Read more

[ESRI software] ESRI Web site providing various online resourcessuch as online help, user forums, blogs, samples, user communities, developer content, and so onto help users learn about and use a … Read more

[Internet] Acronym for Representational State Transfer. An architecture for exchanging information between peers in a decentralized, distributed environment. REST allows programs on different computers to communicate independently of an operating … Read more

[network analysis] A Boolean network element attribute used for limiting traversal through a network dataset. “One way street,” “no trucks allowed,” and “buses only” are examples of restrictions.

[geocoding] The process of finding a street address from a point on a map.