GIS Dictionary

[programming] A common, flexible, programming language.

[programming] An object-oriented programming language, extended from C.

[defense] In defense, an abbreviation used to signify that a computer program or system supports command, control, communication, computers, and information.

[graphics computing] Acronym for computer-aided design. A computer-based system for the design, drafting, and display of graphical information. Also known as computer-aided drafting, such systems are most commonly used to … Read more

The feature representation of a CAD file in a geodatabase-enforced schema. A CAD feature dataset is comprised of five read-only feature classes: points, polylines, polygons, multipatch and annotation. ArcGIS supported … Read more

1 [graphics computing] The digital equivalent of a drawing, figure, or schematic created using a CAD system. 2 [ESRI software] In ArcCatalog, an item in the Catalog tree representing all … Read more

[ESRI software] The pictorial representation of an entire CAD file that can be viewed in any ArcGIS application with a display. The CAD drawing dataset is a vector data source … Read more

[ESRI software] A read-only member of a CAD feature dataset, comprised of one of the following: polylines, points, polygons, multipatch, or annotation. The feature attribute table of a CAD feature … Read more

[ESRI software] The feature representation of a CAD file in a geodatabase-enforced schema. A CAD feature dataset is comprised of five read-only feature classes: points, polylines, polygons, multipatch and annotation. … Read more

[ESRI software] The digital equivalent of a drawing, figure, or schematic created using a CAD system. CAD files are the data source for CAD drawing datasets, feature datasets and feature … Read more

1 [ESRI software] A layer that references a set of CAD data. CAD data is vector data of a mixed feature type. CAD layers may be of two types: CAD … Read more

[database structures] A normalized, fixed set of feature classes and data tables of a predefined schema from a collection of input CAD drawings.

[ESRI software] In Survey Analyst – Cadastral Editor, a network of connected parcels. Parcels are represented by parcel line features, parcel point features, and parcel polygon features, referred to in … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, a number assigned to a parcel line that determines how much the line influences the coordinates that result from a least-squares adjustment. … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, the record of changes to the legal and system state of the cadastral fabric.

[ESRI software] In Survey Analyst – Cadastral Editor, a collection of parcels that have been extracted from the cadastral fabric for editing and least-squares adjustment. Parcels in the cadastral fabric … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, the map representation of a cadastral fabric for which display properties may be set; a layer in ArcMap that represents the cadastral … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, a point that allows a parcel corner to lie on an adjacent parcel boundary line without splitting the boundary line. Line points … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, a parcel line feature in the cadastral fabric that contains dimension information. Represents parcel boundaries. Parcel lines connect up to form parcel … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, a line type that defines how a parcel line in the cadastral fabric will be managed by the cadastral fabric editor. For … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, a point represents a parcel corner or the end of a connection line. A parcel point always has computed x- and y-coordinates.

[ESRI software] In Survey Analyst – Cadastral Editor, an internal feature class that forms part of the cadastral fabric. Cadastral Fabric sublayers include lines, points, polygons, line points, and control … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, the topological relationships explicit in the cadastral fabric data model.

surveying

[cadastral and land records] A boundary survey taken for the purposes of ownership and taxation.

An official record of the dimensions and value of land parcels, used to record ownership and assist in calculating taxes.

1 [accuracy] The comparison of the accuracy of an instrument’s measurements to a known standard. 2 [spatial analysis] In spatial analysis, the selection of attribute values and computational parameters that … Read more

[graphics map display] A line on a map extending between a feature’s geographic position and its corresponding symbol or label, used in areas where there is not enough room to … Read more

[ESRI software] In ArcScene and ArcGlobe, an object that defines the perspective of a scene or globe’s display.

[ESRI software] A record returned as a potential match for an address in the geocoding process.

[computing] In a relational database, any key that can be used as the primary key in a table.

[analysisgeoprocessing] In location-allocation, the maximum number of people or units that a center can service, contain, or have assigned to it.

[ESRI software] In ArcGIS, the text for a command that appears with the “Text Only” and “Image and Text” display types. As part of the user interface, captions are customizable … Read more

[navigation] One of the four compass directions on the earth’s surface: north, south, east, or west.

[mathematics] The correspondence or equivalency between sets; how sets relate to each other. For example, if one row in a table is related to three rows in another table, the … Read more

[physics] An electromagnetic wave, such as radio, with modulations that are used as signals to transmit information.

[GPS] Signal processing that uses the GPS carrier signal to lock onto the PRN code generated by the satellite.

[GPS] GPS measurements that are calculated using the carrier signal of a satellite.

[symbology] A single line representing multiple coincident contour lines, used to show vertical topographic features such as cliffs, cuts, and fills.

A two-dimensional, planar coordinate system in which horizontal distance is measured along an x-axis and vertical distance is measured along a y-axis. Each point on the plane is defined by … Read more

Euclidean geometry

[map design] A diagram or abstract map in which geographical areas are distorted proportionally to the value of an attribute.

[cartography] One who practices the art and science of expressing graphically, usually through maps, the natural and social features of the earth.

[cartography] The abstraction, reduction, and simplification of features so that a map is clear and uncluttered at a given scale.

[cartography] The art and science of expressing graphically, usually through maps, the natural and social features of the earth.

[map design] An ornamental frame on a map, usually around the map’s title. Cartouches are rarely used on modern maps.

[non-ESRI software] Acronym for computer-aided software engineering. Any software that assists with the development and maintenance of software, especially the analysis and design. Complex tasks that often require many lines … Read more

[ESRI software] In ArcCatalog or ArcMap’s Catalog window, a hierarchical view of folder connections which provide access to GIS data stored on local disks or shared on a network that … Read more

[non-ESRI software] Acronym for Component Category ID. A unique string assigned to locally related COM classes to group them together. A CATID is a type of Globally Unique IDentifier (GUID).

[government] A geographic region containing at least one urban area with a population of at least 10,000, defined by the U.S. Office of Management and Budget for use by federal … Read more

[hardware] An optical disk, slightly less than 5 inches in diameter, used to store up to approximately 650 megabytes of data.

[astronomy] The sky, considered as the inside of a sphere of infinitely large radius that surrounds the earth, on which all celestial bodies except the earth are imagined to be … Read more

1 [graphics computing] The smallest unit of information in raster data, usually square in shape. In a map or GIS dataset, each cell represents a portion of the earth, such … Read more

[analysisgeoprocessing] The process of selecting raster cells either interactively or by using a SQL query.

[data models] The dimensions on the ground of a single cell in a raster, measured in map units. Cell size is often used synonymously with pixel size.

[ESRI software] An ArcGIS Spatial Analyst function that calculates a statistic for each cell of an output raster that is based on the values of each cell in the same … Read more

[modeling] A mathematical construction consisting of a row or grid of cells in which each cell has an initial valuefrom a known and limited number of possible valuesand all cells … Read more

[federal government] The smallest geographic entity for which the U.S. Census Bureau tabulates decennial census data. Many blocks correspond to city blocks bounded by streets, but blocks in rural areas … Read more

[federal government] Any one of various types of precisely defined geographic areas used by the U.S. Census Bureau to collect and aggregate data. The largest unit of area is the … Read more

[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

[Euclidean geometry] The point in a circle or in a sphere equidistant from all other points on the object.

[data capture] A line digitized along the center of a linear geographic feature, such as a street or a river, that at a large enough scale would be represented by … Read more

[data capture] The generation of vector features along the center of connected cells. It is typically used for vectorizing scanned parcel and survey maps.

In aerial photography, the point at the exact center of an aerial photograph.

[coordinate systems] The line of longitude that defines the center and often the x-origin of a projected coordinate system. In planar rectangular coordinate systems of limited extent, such as state … Read more

[data capture] The geometric center of a feature. For line, polygon, or three-dimensional features, it is the center of mass (or center of gravity) and may fall inside the feature, … Read more

[computing] Acronym for Common Gateway Interface. A standard for scripts that run external programs from a World Wide Web server. CGI typically specifies how to pass arguments to the program … Read more

[surveying] A unit of length equal to 66 feet, used especially in U.S. public land surveys. Ten square chains equal 1 acre.

[data capture] A method of drawing a polygon as a series of straight line segments defined as a set of directional codes, with each code following the last like links … Read more

[remote sensing] A process that measures how the attributes of a particular area have changed between two or more time periods. Change detection often involves comparing aerial photographs or satellite … Read more

[computing] A letter, digit, or special graphic symbol treated as a single unit of data and usually stored as one byte.

1 [cartography] A map used to plot a course for air or water navigation. 2 [mathematics] A graphic representation of tabular data; a diagram showing the relationship between two or … Read more

[ESRI software] In disconnected editing, the procedure that transfers a copy of data into a master geodatabase, overwriting the original copy of that data and reenabling it so it can … Read more

[ESRI software] A procedure in disconnected editing that records the duplication of data from one geodatabase to another and disables the original data so that both versions cannot be accessed … Read more

[ESRI software] In ArcGIS versions 8.39.1, a personal or ArcSDE geodatabase that contains data checked out from a master geodatabase during disconnected editing.

[ESRI software] The data version created in a checkout geodatabase when data is checked out to that database during disconnected editing. The checkout version is created as a copy of … Read more

[ESRI software] A type of geodatabase replication that involves copying data to a destination geodatabase, editing that data in the destination, and then merging the changes with the source geodatabase. … Read more

[statistics] A statistic used to assess how well a model fits the data. It compares categorized data with a multinomial model that predicts the relative frequency of outcomes in each … Read more

[ESRI software] In geodatabase editing, data that has been copied to a destination geodatabase during the replication process.

A straight line that joins two points on a curve.

[cartography] A thematic map in which areas are distinctly colored or shaded to represent classed values of a particular phenomenon.

The saturation, purity, or intensity of a color.

[navigation] Acronym for Chart Updating Manual. A document containing updates to aeronautical information, used by the U.S. military to update their current published products with the latest information.

[Euclidean geometry] A two-dimensional geometric shape for which the distance from the center to any point on the edge is equal; the closed curve defining such a shape.

[Euclidean geometry] A curved line that is a section of a circle, with two vertices, one situated at each endpoint.

[spatial statistics use for geostatistics] A measure of directional variation, on a scale from zero to one, among a set of line vectors. Circular variance approaches zero when all vectors … Read more

[GPS] The standard PRN code used by most civilian GPS receivers.

[astronomy] An orbit 22,245 miles (35,800 kilometers) above the equator in which a satellite travels at the same speed that the earth rotates. The Clarke Belt was named after the … Read more

[geodesy] A reference ellipsoid having a semimajor axis of approximately 6,378,206.4 meters and a flattening of 1/294.9786982. It is the basis for the North American Datum of 1927 (NAD27) and … Read more

1 [data analysis] A set of entities grouped together on the basis of shared attribute values. 2 [data models] Pixels in a raster file that represent the same condition. 3 … Read more

A set of categories for classification that divide the range of all values so that each piece of data is contained within a nonoverlapping category.

[cartography] The process of sorting or arranging entities into groups or categories; on a map, the process of representing members of a group by the same symbol, usually defined in … Read more

[ESRI software] An ASCII file in the geocoding rule base that identifies and classifies keywords that may appear in an address, such as street types and directions. Classification tables have … Read more

[programming] Acronym for Connected Limited Device Configuration. A framework for developing J2ME applications for devices with very limited resources, such as wireless devices.

[data quality] Data that is free from error.

[data conversion] Improving the appearance of scanned or digitized data by correcting overshoots and undershoots, closing polygons, performing coordinate editing, and so on.

[data sharing] A repository structure, physical or virtual, that collects, stores, and disseminates information, metadata, and data. A clearinghouse provides widespread access to information and is generally thought of as … Read more

[computing] An application, computer, or device in a client/server model that makes requests to a server.

[ESRI software] An address locator that is created and used on the same computer.

[computing] A software system with a central processor (server) that accepts requests from one or more user applications, computers, or devices (clients). Although client/server architecture can exist on one computer, … Read more