GIS Dictionary

1 [ESRI software] In ArcMap, ArcScene, and ArcGlobe, an ordered collection of similar keyframes that, when played as an animation, shows a dynamic transition between them. 2 [ESRI software] In … Read more

[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.