GIS Dictionary

[computing] A database company that produces a relational database management system (also called Oracle), which allows data and other objects to be stored in tables. Oracle provides client/server access to … Read more

[ESRI software] In ArcGIS Network Analyst, a network location used to determine routes in vehicle routing problem (VRP) analysis. Users can specify multiple orders. Orders may represent any combination of … Read more

[ESRI software] In ArcGIS Network Analyst, an object used in vehicle routing problem (VRP) analysis. An order pair defines a relationship between two orders. The first order in the order … Read more

[data structures] Data classified by comparative value; for example, a group of polygons colored lighter to darker to represent less to more densely populated areas.

A kriging method in which the weights of the values sum to unity. It uses an average of a subset of neighboring points to produce a particular interpolation point.

[Euclidean geometry] In a rectangular coordinate system, the distance of the y-coordinate along a vertical axis from the horizontal or x-axis. For example, a point with the coordinates (7,3) has … Read more

[cartography] The national mapping and cartographic agency of the United Kingdom. Now a civilian organization, the Ordnance Survey is one of the world’s largest producers of maps and was the … Read more

1 [geography] An object’s position or relationship in direction with reference to points of the compass. 2 [ESRI software] In Survey Analyst for field measurements, the method by which horizontal … Read more

[ESRI software] An option that controls whether a label can be placed in an upside-down or sideways position. A small angle prevents labels from switching their reading order in the … Read more

1 [coordinate systems] A fixed reference point in a coordinate system from which all other points are calculated, usually represented by the coordinates (0,0) in a planar coordinate system and … Read more

[ESRI software] In ArcGIS Network Analyst, a type of network analysis that computes a table containing the total impedance from each origin to each destination. Additionally, it ranks the destinations … Read more

[Euclidean geometry] Intersecting at right angles.

[Euclidean geometry] A line that is perpendicular to another line at its point of tangency, often used to measure distance from a line to a separate point that does not … Read more

A planar projection, tangent to the earth at one point, that views the earth’s surface from a point approaching infinity, as if from deep space.

[ESRI software] In 3D Analyst, a perspective that allows viewing of data in a scene as a two-dimensional plane seen from above. There is no perspective foreshortening in orthographic view, … Read more

[aerial photography] An aerial photograph from which distortions owing to camera tilt and ground relief have been removed. An orthophoto has the same scale throughout and can be used as … Read more

An orthophotograph that has been formatted as a USGS 1:24,000 topographic quadrangle with little or no cartographic enhancement.

[aerial photography] A photomechanical or optical-electronic device that creates an orthophotograph by removing geometric and relief distortion from an aerial photograph.

[satellite imaging] The process of correcting the geometry of an image so that it appears as though each pixel were acquired from directly overhead. Orthorectification uses elevation data to correct … Read more