GIS Dictionary

[software] The act of distributing application, network, and/or server resources to optimize performance.

[data editing] The computation of an output raster where the output value at each location is a function of the input value at the same location.

[ESRI software] In Survey Analyst for field measurements, one of two ways to apply the Coordinate Out of Tolerance command. The Local check method searches for coordinates out of tolerance … Read more

1 [geodesy] A horizontal geodetic datum that serves as a basis for measurements over a limited area of the earth; that has its origin at a location on the earth’s … Read more

[spatial statistics use for geostatistics] In ArcGIS Geostatistical Analyst, a deterministic interpolation method. The interpolated surface is not required to conform to the sample data points, and the method does … Read more

[organizational issues] The process of adapting software to the requirements of a different language or culture, including translating user interfaces, documentation, and help systems; customizing features; and accommodating different character … Read more

1 [geography] An identifier assigned to a region or feature. 2 [geography] A position defined by a coordinate value.

[non-ESRI software] Services that allow IBM WebSphere Everywhere Access (WEA) application providers to use location-based services from multiple vendors, by providing an application programming interface (API).

The process of finding the best locations for one or more facilities that will service a given set of points and then assigning those points to the facilities, taking into … Read more

[location-based services] Information or a physical service delivered to multiple channels, exclusively based on the determined location of a wireless device. Some location-based applications include emergency services, information services, and … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, a parcel that has been locked for editing. Locked parcels cannot be edited simultaneously in a multiuser environment.

[wayfinding] The movements of a person following a route. Locomotion is the physical component of navigation.

[computing] A database file that records changes in data, often used as part of a database restoration.

[mathematics] The power to which a fixed number (the base) must be raised to equal a given number. The three most frequently used bases for logarithms are base 10, base … Read more

[mathematics] A string of numbers, constants, variables, operators, and functions that returns a value of true or false.

[ESRI software] An abstract representation of a network, implemented as a collection of hidden tables. A logical network contains edge, junction, and turn elements, the connectivity between them, and the … Read more

[mathematics] An operator used to compare logical expressions that returns a result of true or false. Examples of logical operators include less than (), equal to (=), and not equal … Read more

[analysisgeoprocessing] The process of using mathematical expressions to select features from a geographic layer based on their attributes; for example, “select all polygons with an area greater than 16,000 units” … Read more

[ESRI software] An edit session on a feature dataset that may last from a few minutes to several months. Long transactions are managed by the ArcSDE versioning mechanism.

[spatial statistics use for geostatistics] In a spatial model, coarse-scale variation that is usually modeled as the trend.

The angular distance, usually expressed in degrees, minutes, and seconds, of the location of a point on the earth’s surface east or west of an arbitrarily defined meridian (usually the … Read more

The longitude value that defines the center, and sometimes the origin, of a projection.

The longitude value that defines the origin of the x-coordinate values for a projection.

A relatively unstructured relationship between two software components or programs that work together to process data, which requires little overlap between methods, ontologies, class definitions, and so on.

[ESRI software] A replication model that does not require the parent and child replicas to be directly connected for synchronization to occur. Loosely coupled replication is an asynchronous model, so … Read more

[data transfer] Data compression that has the ability to store data without changing any of the values, but is only able to compress the data at a low ratio (typically … Read more

[data transfer] Data compression that provides high compression ratios (for example 10:1 to 100:1), but does not retain all the information in the data. In GIS, lossy compression is used … Read more

[empty] A measured parcel of land having fixed boundaries and designated on a plot or survey.

[programming] A programming language that uses keywords and statements that are little more complex than the ones and zeros of machine language. Low-level language technically includes machine language, but more … Read more

[remote sensing] A spatial filter that blocks high-frequency (shortwave) radiation, resulting in a smoother image.