GIS Dictionary

[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