GIS Dictionary

[ESRI software] In ArcGIS Tracking Analyst, a field containing a unique identifier for a given object or objects being observed. This field is used to join the components of a … Read more

[ESRI software] A message or Internet connection whereby real-time data can stream into ArcGIS Tracking Analyst.

[federal government] A small, statistical subdivision of a county that usually includes approximately 4,000 inhabitants but may include from 2,500 to 8,000 inhabitants. A census tract is designed to encompass … Read more

1 [computing] A group of data operations that comprise a complete operational task, such as inserting a row into a table. 2 [ESRI software] A logical unit of work as … Read more

[linear referencing] In linear referencing, an operation that produces a new table by copying and transforming events from one route reference to another. This allows the events to be used … Read more

[data conversion] The process of converting the coordinates of a map or an image from one system to another, typically by shifting, rotating, scaling, skewing, or projecting them.

1 A rule for adjusting the closure error in a traverse. The transit rule distributes the closure error by changing the northings and eastings of each traverse point in proportion … Read more

1 [data editing] Adding a constant value to a coordinate. 2 [data conversion] Converting data from one format to another, usually in order to move it from one system to … Read more

[map projections] A map projection whose line of tangency is oriented along a meridian rather than along the equator.

[network analysis] A Hamiltonian circuit problem in which a salesperson must find the most efficient way to visit a series of stops, then return to the starting location. In the … Read more

1 [surveying] A predefined path or route across or over a set of geometric coordinates. 2 [surveying] A method of surveying in which lengths and directions of lines between points … Read more

[ESRI software] In ArcMap and Survey Analyst for field measurements, a group of observed values that define a new coordinate. A traverse course starts from a preexisting coordinate, or a … Read more

A common data structure consisting of a set of nodesbasic units of datalinked hierarchically. Each node can contain one or more subordinate nodes within it, in which case it is … Read more

[spatial statistics use for geostatistics] In a spatial model, nonrandom variation in the value of a variable that can be described by a mathematical function such as a polynomial.

A surface interpolation method that fits a polynomial surface by least-squares regression through the sample data points. This method results in a surface that minimizes the variance of the surface … Read more

1 [Euclidean geometry] Any closed, three-sided, two-dimensional polygon. 2 [Euclidean geometry] A face on a TIN surface. Each triangle on a TIN surface is defined by three edges and three … Read more

[surveying] Locating positions on the earth’s surface using the principle that if the measures of one side and the two adjacent angles of a triangle are known, the other dimensions … Read more

[ESRI software] A piece of code in a database management system (DBMS) that executes in response to data being modified with an INSERT, UPDATE, or DELETE statement.

[ESRI software] An operator within the Raster Calculator of ArcGIS Spatial Analyst that performs various trigonometric calculations on the values in an input raster. Available trigonometric functions include Sin, Cos, … Read more

[surveying] Determining the position of a point on the earth’s surface with respect to two other points by measuring the distances between all three points.

[navigation] A bearing measured relative to true north.

[geography] The direction from any point on the earth’s surface to the geographic north pole.

An individual row or record in a database table. Each tuple records the values for the columns defined in the table.

[network analysis] In network analysis, a movement that explicitly models transitions between edge elements during navigation.

[network analysis] A specialized feature class that defines turn movements in an ArcGIS network dataset. Turn features explicitly model subsets of possible transitions between edge elements during navigation, and may … Read more

[network analysis] In network analysis, the cost of making a turn at a network node. The impedance for making a left turn, for example, can be different from the impedance … Read more

In ArcInfo Workstation and ArcView GIS 3, a table that stores information about the cost of making each turn movement in a network. A turn table identifies the edge that … Read more

[map design] A series of small maps detailing where route segments meet.

[graphics computing] In animated applications, the process of creating intermediate frames between two images so it seems like the first image merges smoothly into the second image.

[programming] A software configuration in which two software applications (commonly a client and a server) work together to accomplish a task.

[ESRI software] A type of geodatabase replication that allows data changes to be sent multiple times from the parent replica to the child replica or from the child replica to … Read more

[programming] In programming, a kind of inheritance in which an interface may inherit from a parent interface. A client may call the child interface as if it were the parent, … Read more

[programming] A collection of reusable classes, interfaces, enumerations, and so on that can be included in programs. Type libraries usually have the extension .olb.