GIS Dictionary

[computing] In programming, a process that continuously runs in the background, without being explicitly implemented, and performs a specified operation at predefined times or in response to certain events. Daemon … Read more

[data capture] The endpoint of a dangling arc.

[data capture] In ArcInfo coverages, the minimum length allowed for dangling arcs by the clean process, which removes dangling arcs shorter than the dangle tolerance.

[data capture] An arc having the same polygon on both its left and right sides and having at least one node that does not connect to any other arc. It … Read more

[data analysis] A technique in which attribute data that is organized by a large or arbitrary area unit is more accurately distributed within that unit by the overlay of geographic … Read more

[data management] Any collection of related facts arranged in a particular format; often, the basic elements of information that are produced, stored, or processed by a computer.

[data capture] Any operation that converts GIS data into computer-readable form. Geographic data can be captured by being downloaded directly into a GIS from sources such as remote-sensing or GPS … Read more

[ESRI software] In ArcGIS, a message containing any inserts, updates, and deletes applied to a replica. These messages are used to synchronize replicas in a disconnected environment.

[data conversion] The process of translating data from one format to another.

[programming] A set of SQL statements that can be used either interactively or within a programming language to create a new database, set permissions on it, and define its attributes.

[data management] A catalog or table containing information about the datasets stored in a database. In a GIS, a data dictionary might contain the full names of attributes, meanings of … Read more

[data transfer] The smallest unit of information used to describe a particular characteristic of a spatial dataset. A data element is a logically primitive description that cannot be further subdivided.

[computing] A file that holds text, graphics, or numbers.

[data structures] The structure used to store a computer file or record.

[data structures] The structure used to store a computer file or record.

[ESRI software] A map element that defines a geographic extent, a page extent, a coordinate system, and other display properties for one or more layers in ArcMap. A dataset can … Read more

[ESRI software] A map element that defines a geographic extent, a page extent, a coordinate system, and other display properties for one or more layers in ArcMap. A dataset can … Read more

[interoperability] The process of sharing and combining data between two organizations or systems.

[interoperability] The process of sharing and combining data between two organizations or systems.

The degree to which the data in a database is accurate and consistent according to data model and data type.

The degree to which the data in a database is accurate and consistent according to data model and data type.

[GPS] Information in a satellite’s GPS signal that reports its orbital position, operating health, and clock corrections.

[GPS] Information in a satellite’s GPS signal that reports its orbital position, operating health, and clock corrections.

1 [data models] In GIS, a mathematical construct for representing geographic objects or surfaces as data. For example, the vector data model represents geography as collections of points, lines, and … Read more

1 [data models] In GIS, a mathematical construct for representing geographic objects or surfaces as data. For example, the vector data model represents geography as collections of points, lines, and … Read more

[GPS] A lightweight, handheld field computer used to store data collected by a GPS receiver.

[GPS] A lightweight, handheld field computer used to store data collected by a GPS receiver.

Making data available and accessible to organizations or individuals other than the creator of the data.

[data management] Any data. Data sources may include coverages, shapefiles, rasters, or feature classes.

[data structures] The organization of data within a specific computer system that allows the data to be stored and manipulated effectively; a representation of a data model in computer form.

[ESRI software] The process of applying data changes from a replica to the relative replica in a replica pair. Data changes include row or feature inserts, updates, and deletes. Synchronization … Read more

[data transfer] The process of moving data from one system to another or from one point on a network to another.

[data storage] The attribute of a variable, field, or column in a table that determines the kind of data it can store. Common data types include character, integer, decimal, single, … Read more

[ESRI software] An all-purpose view in ArcMap and ArcReader for exploring, displaying, and querying geographic data. This view hides all map elements, such as titles, north arrows, and scale bars.

A type of market analysis primarily used to look at competing sites or to select potential new locations.

[data storage] One or more structured sets of persistent data, managed and stored as a unit and generally associated with software to update and query the data. A simple database … Read more

[data management] The person who manages a database. Database administration includes user setup, security, backup and recovery procedures for data, and optimization of physical data storage for best performance.

[data management] A link to a database from a software application. Database connections have two states: connected to or disconnected from the database. Deletion of a database connection only deletes … Read more

[database structures] The development of the conceptual, logical, and physical structures of a database in order to meet user requirements.

[database structures] The abstraction, reduction, and simplification of features and feature classes for deriving a simpler model of reality or decreasing stored data volumes.

[database structures] A set of software applications used to create and maintain databases according to a schema. Database management systems provide tools for adding, storing, changing, deleting, and retrieving data.

[ESRI software] The database permissions category assigned to a group of users who perform the same types of tasks and, therefore, require the same level of database access. Database roles … Read more

[ESRI software] Mathematically calculated data that describes the state of a database and which the database management system (DBMS) uses to optimize query response.

[database structures] The proprietary database platforms supported by a program or component.

[data models] The route of data passage through a system.

[data management] Any collection of related data, usually grouped or stored together.

[data quality] The mathematical exactness or detail with which a value is stored within a dataset, based on the number of significant digits that can be stored for each coordinate.

[ESRI software] In Survey Analyst, the process of testing each measurement using the W-test.

The reference specifications of a measurement system, usually a system of coordinate positions on a surface (a horizontal datum) or heights above or below a surface (a vertical datum).

[geodesy] A surface to which heights, elevations, or depths are referenced.

In Survey Analyst for field measurements, survey points that are not defined by computations, but that are the input data for the initial computations in a sequence of computations.

[ESRI software] A database file format.

[non-ESRI software] Acronym for Distributed Component Object Model. Extends COM to support communication among objects on different computers on a network.

[navigation] A navigation method of last resort that uses the most recently recorded position of a ship or aircraft, along with its speed and drift, to calculate a new position.

[computing] To test for, detect, and correct errors in a computer program or component.

[map projections] Values of latitude and longitude expressed in decimal format rather than in degrees, minutes, and seconds.

[computing] A computer program that includes data presentation and modeling tools that help people understand problems and find solutions.

1 [coordinate systems] In a spherical coordinate system, the angle between the equatorial plane and a line to a point somewhere on the sphere. 2 [coordinate systems] The arc between … Read more

[computing] An application that uses the GIS server to maintain application state by changing the state of a server object or its related objects. Deeply stateful applications require nonpooled server … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, the most up-to-date version of the cadastral fabric in the database that corresponds to the default version in the database. The default … Read more

[Internet] When a COM object is created, the interface that is returned automatically if no other interface is specified. Most ArcObjects classes specify IUnknown as the default interface.

[network analysis] In geometric networks, the user-established junction type that automatically connects two edges in the absence of a current user choice. An edge may also have a default end … Read more

[ESRI software] A study area with a defined boundary, such as a city.

[ESRI software] In ArcMap, a request that examines feature or tabular attributes based on user-selected criteria and displays only those features or records that satisfy the criteria.

[data editing] The creation of a segment at an angle relative to an existing segment.

[geodesy] A unit of angular measure represented by the symbol . The earth is divided into 360 degrees of longitude and 180 degrees of latitude.

The unit of measure for describing latitude and longitude. A degree is 1/360th of a circle. A degree is further divided into 60 minutes, and a minute is divided into … Read more

[3D analysis] The components of Delaunay triangulation. Delaunay triangles cannot exist alone; they must exist as part of a set or collection that is typically referred to as a triangulated … Read more

[3D analysis] A technique for creating a mesh of contiguous, nonoverlapping triangles from a dataset of points. Each triangle’s circumscribing circle contains no points from the dataset in its interior. … Read more

[database structures] The geodatabase system table, created when a feature class or table is registered as versioned, that maintains information on all rows that have been deleted or updated.

[computing] A character, such as a space or comma, that separates words or values.

[data editing] A file that contains data edits that can be exchanged between geodatabases or between geodatabases and other data stores. The edits can come from a checkout geodatabase, modified … Read more

[database structures] One of two geodatabase system tablesthe adds and deletes tablescreated for a feature class or table when it is registered as versioned. These tables record changes made to … Read more

[data models] Acronym for digital elevation model. The representation of continuous elevation values over a topographic surface by a regular array of z-values, referenced to a common vertical datum. DEMs … Read more

[geography] The statistical characteristics (such as age, birth rate, and income) of a human population.

[geography] The statistical study of human populations, especially their locations, distribution, economic statistics, and vital statistics.

[data editing] To add vertices to a line at specified distances without altering the line’s shape.

[graphics map display] An instrument for measuring the opacity of translucent materials such as photographic negatives and optical filters.

1 [Euclidean geometry] In spatial measurements, the quantity per unit area or length. 2 [physics] In a substance such as a gas, solid, or liquid, a measurement of the ratio … Read more

[remote sensing] A technique normally applied to a single-band monochrome image for highlighting areas that appear to be uniform in tone, but are not. Grayscale values (0-255) are converted into … Read more

[statistics] The variable representing the process being predicted or modeled, such as crime, foreclosure, or rainfall. The dependent variable is a function of the independent variables. Regression can be used … Read more

[computing] The installation of a component or application on a target machine.

[ESRI software] In ArcGIS Network Analyst, a network location used to represent a starting, stopping, or renewal location for routes in vehicle routing problem (VRP) analysis. Users can specify multiple … Read more

[ESRI software] In ArcGIS Network Analyst, an object used to represent a single visit to a specific depot in vehicle routing problem (VRP) analysis. A depot visit may occur at … Read more

[symbology] A line on a map connecting points of equal depth below a hydrographic datum.

In ModelBuilder, data created by running a geoprocessing operation on existing data. Derived data from one process can serve as input data for another process.

The point at which a satellite traveling north to south crosses the equator.

[network analysis] A type of attribute for network elements that cannot be apportioned. The value of a descriptor stays the same through the length of an edge element in a … Read more

[data analysis] A type of market analysis that draws lines from a set of geocoded points (usually customers) to a single, central point (usually a store). Desire lines can be … Read more

[data management] Mapping software that is installed onto and runs on a personal computer and allows users to display, query, update, and analyze data about geographic locations and the information … Read more

[computing] The secondary object in a relationship class, such as a table containing attributes associated with features in a related table.

[ESRI software] In ArcView 3.x, one of the two tables involved in a join operation. The destination table must be the active table; the attributes of the source (inactive) table … Read more

[ESRI software] One of two types of pages in the Survey Analyst Survey Explorer. The Detail page displays a detailed view of individual survey objects.

[network analysis] A conclusively definitive line or course in which something is issuing or moving in a stream. For an edge feature, this occurs when the flow direction can be … Read more

[spatial statistics use for geostatistics] In spatial modeling, a type of model or a part of a model in which the outcome is completely and exactly known based on known … Read more

[statistics] The process of removing the trend from a spatial model by subtracting the trend surface (usually polynomial functions of the spatial x- and y-coordinates) from the original data values. … Read more

[map projections] A geometric shape such as a cone, cylinder, or plane that can be flattened without being distorted. Many map projections are classified in terms of these shapes.

[ESRI software] Products that can be used on one machine, similar to single use products. Each developer product requires a unique registration number used to generate the authorization file. The … Read more

[ESRI software] A sample contained in the ArcGIS Developer Help system.

[programming] A software product used to write, compile, and debug components or applications.