GIS Dictionary

[GPS] The PRN code used by United States and allied military GPS receivers.

[statistics] A probability resulting from a statistical test of the coefficient associated with each independent variable in a regression model. The null hypothesis for this statistical test states that the … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, an XML stream or file containing the portion of the cadastral fabric that has been extracted by a cadastral fabric job for … Read more

The unit of measure, usually millimeters or inches, used to arrange map elements on a page for printing, as opposed to the coordinate system on the ground that the map … Read more

[map display] To shift a map image relative to the display window without changing the viewing scale.

[digital image processing] Sharpening a low-resolution multiband image by merging it with a high-resolution panchromatic image.

[remote sensing] Sensitive to light of all wavelengths in the visible spectrum.

[map design] A map spliced together from smaller maps of neighboring areas.

[photogrammetry] The apparent shift in an object’s position when it is viewed from two different angles.

[geodesy] An imaginary eastwest line encircling the earth, parallel to the equator and connecting all points of equal latitude. Also, the representation of this line on a globe or map.

[computing] In computer data communications, a method of storing or sending data side by side, in groups of bits. Parallel data transmission is most often used for printer ports.

1 [map projections] One of the variables that define a specific instance of a map projection or a coordinate system. Parameters differ for each projection and can include central meridian, … Read more

[mathematics] A curve that is defined mathematically rather than by a series of connected vertices. A parametric curve has only two vertices, one at each end.

1 [cadastral and land records] A piece or unit of land, defined by a series of measured straight or curved lines that connect to form a polygon. 2 [ESRI software] … Read more

[ESRI software] In Survey Analyst – Cadastral Editor, a set of dimensions entered to create a set construction line work.

[ESRI software] In Survey Analyst – Cadastral Editor, a set of parcels that exist as a group instead of individually in a cadastral fabric job.

[cadastral and land records] Acronym for parcel identification number. In Survey Analyst – Cadastral Editor, a unique identifier for a parcel. The format of an identifier is defined by the … Read more

[cadastral and land records] A classification for parcels, used to provide additional information about them and how they must be treated for least squares adjustment. Standard parcels, blocks, and easements … Read more

[ESRI software] In geodatabase editing, data in a source geodatabase that is replicated.

1 [computing] In computing, to divide a sequence of letters and numbers into parts, especially to test their agreement with a set of syntax rules. 2 [education] To break a … Read more

[geocoding] The ability to return a list of geocoding candidates based on incomplete address information. For example, if a city name but no country is entered in a partial address … Read more

[ESRI software] In ArcGlobe, an on-demand cache that contains levels of detail for areas that have been visited, or a pre-processed cache that has a specified, incomplete, level of detail … Read more

[spatial statistics use for geostatistics] A parameter of a covariance or semivariogram model that represents the variance of a spatially autocorrelated process without any nugget effect. In the semivariogram model, … Read more

[remote sensing] A remote-sensing system, such as an aerial photography imaging system, that only detects energy naturally reflected or emitted by an object.

[remote sensing] Imaging sensors that can only receive radiation, not transmit it.

[computing] A string of characters that a user must enter to access a computer, program, database, or Web site. Passwords are a means of protecting and restricting access to information … Read more

[3D GIS] A single triangular face inside a multipatch geometry. In most cases, many patches (faces) are used together to create a complex 3D model. Examples include geometric shapes, such … Read more

1 [network analysis] The connecting lines, arcs, or edges that join an origin to a destination. 2 [computing] In computing, the location of a computer file, given as the drive, … Read more

[spatial analysis] In ArcGIS Spatial Analyst, a description of each cell’s least accumulative cost relationship to a source or a set of sources, accounting for surface distance, horizontal cost factors … Read more

[ESRI software] A label that describes the nature of the association between the objects in a relationship. The forward path label describes the relationship when navigating from the origin to … Read more

[network analysis] The process of calculating the optimal path between an origin and a destination point or points in a network.

In image processing, the computer-based identification, analysis, and classification of objects, features, or other meaningful regularities within an image.

[data structures] Acronym for Portable Document Format. A proprietary file format from Adobe that creates lightweight text-based, formatted files for distribution to a variety of operating systems.

1 [geography] The highest point of a mountain or hill. 2 [modeling] In modeling, a point on a surface around which all slopes are negative.

[Euclidean geometry] A measurement of the rate of change of elevation over a given horizontal distance, in which the rise is divided by the run and then multiplied by one … Read more

[computing] A measure of the speed at which a computer system works. Factors affecting performance include availability, throughput, and response time.

[astronomy] In an orbit path, the point at which the object in orbit is closest to the center of the body being orbited.

[data management] A dataset permanently stored on disk.

[intellectual property rights] A license that has a time-out date listed as permanent, indicating that the license for a particular product does not expire.

[computing] In computing, the process of saving or storing data; retaining the current state of an object in a memory storage medium such as a database or file on disk.

[database structures] A geodatabase that stores data in Microsoft Access. A personal geodatabase can be read simultaneously by several users, but only one user at a time can edit the … Read more

[3D GIS] A projection mode in 3D applications that allows viewing from a perspective that can be controlled by navigating the scene or globe from a specified location.

[aerial photography] The science of interpreting and mapping geologic features from aerial photographs or remote-sensing data.

The science of making reliable measurements of physical objects and the environment by measuring and plotting electromagnetic radiation data from aerial photographs and remote-sensing systems against land features identified in … Read more

[aerial photography] An aerial photograph or photographs, referenced to a ground control system and overprinted with map symbology.

[physics] An instrument that records the intensity of light by converting incident radiation into an electrical signal and then measuring it.

[geography] The field of geography concerning the natural features of the earth’s surface.

[ESRI software] One of the two parts of a network system; the actual feature classes that participate in a network system.

[graphics computing] A type of fill pattern created by continuous tiling of either a .bmp (raster image) or a .emf (vector graphic) file.

[statistics] A chart shaped like a circle cut into wedges from a center point, that represents percentage values as proportionally sized “slices.” Pie charts are used to represent the relationship … Read more

[ESRI software] In ArcGlobe, anchoring a vector graphic element to the underlying globe surface so that it remains fixed.

1 [geography] A depression in the earth’s surface. 2 [modeling] In modeling, a point on a surface around which all slopes are positive.

1 [data models] The smallest unit of information in an image or raster map, usually square or rectangular. Pixel is often used synonymously with cell. 2 [remote sensing] In remote … Read more

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

[graphics computing] The x,y coordinate space defined by the number of pixels in a computer’s display area, with a pixel being a single unit of color on the screen. Most … Read more

[government] In census geography, any incorporated or unincorporated city, town, or community.

[geocoding] The formal or common name of a location, such as the name of a school, hospital, or other landmark. For example, “Memorial Hospital” is the place name for the … Read more

[surveying] In surveying, a high-level organization of parcels; a survey document containing data from a recorded subdivision survey plan, or from a legal description. Often, many parcels are defined in … Read more

[coordinate systems] A two-dimensional measurement system that locates features on a plane based on their distance from an origin (0,0) along two perpendicular axes.

[data conversion] A set of rules used to define a consistent method of building point, line and polygon features from spaghetti-digitized data. For example, planar enforcement includes rules that polygons … Read more

A projection that transforms points from a spheroid or sphere onto a tangent or secant plane. Because its directions are often true, the planar projection is also known as an … Read more

[data editing] The process of creating multiple line features by splitting longer features at the places where they intersect other line features. This process is often applied to nontopological line … Read more

A survey of a small area that does not take the curvature of the earth’s surface into account.

[aerial photography] Two-dimensional; showing no relief.

[aerial photography] A two-dimensional map that serves as a guide for contour mapping, usually prepared from aerial photographs.

[cartography] A map that displays only the x,y locations of features and represents only horizontal distances.

[aerial photography] Deviations in the horizontal positions of features in an aerial photograph caused by differences in elevation. Planimetric shift causes changes in scale throughout a photograph.

A survey diagram, drawn to scale, of the legal boundaries and divisions of a tract of land.

[software] In computing, the operating system of a machine, such as the UNIX, Linux, or Windows operating systems. Platform may also refer to a programming language or development environment, such … Read more

[ESRI software] The time mode in which data is displayed using the ArcGIS Tracking Analyst Playback Manager, replaying either real-time or fixed-time data.

[ESRI software] The span of time defined by the Start and End text boxes in the ArcGIS Tracking Analyst Playback Manager. This window can be set to include the temporal … Read more

[printing] A printing device that draws an image onto large-size paper or transparencies. Although pen and electrostatic plotters have largely been replaced by large-format inkjet printers, the term plotter is … Read more

[surveying] Acronym for Public Land Survey System. The description of the location of land in the United States using a survey system established by the federal government in 1785. The … Read more

[ESRI software] Acronym for Production Line Tool Set. A software package that allows users to prepare and maintain data for maps, perform quality assurance/quality control tasks, and create map sheets. … Read more

[ESRI software] A tool used to batch load a personal or enterprise geodatabase from a variety of sources (coverages, shapefiles, or geodatabases). The PLTS data loader uses a cross-reference database … Read more

[ESRI software] In PLTS, a tool for managing layer representation, such as symbology and label expressions.

[Internet] A small software application that extends the functionality of a Web browser.

[ESRI software] An additional read-only data source provided by either ESRI or a third-party developer. It may be a data source forming part of the core ArcObjects or an extension.

[surveying] A line that corresponds to the direction of gravity at a point on the earth’s surface; the line along which an object will fall when dropped.

[ESRI software] Acronym for Published Map File. A file exported by the Publisher extension that can be read by ArcReader. Publisher Map Files end with a .pmf extension.

Acronym for Portable Network Graphics. A bitmapped graphics format similar to GIF.

[ESRI software] A geometric element defined by a pair of x,y coordinates.

[ESRI software] In Survey Analyst, part of the validation of survey data. This type of analysis is used to authenticate the relationships between survey points, coordinates, and the physical locations … Read more

[linear referencing] In linear referencing, a feature that occurs at a precise point location along a route and uses a single measure value. Examples include accident locations along highways, signals … Read more

1 [ESRI software] A map feature that has neither length nor area at a given scale, such as a city on a world map or a building on a city … Read more

[ESRI software] A field in the Survey Analyst Survey Explorer dialog box that allows a user to specify the name of a particular survey point.

[data capture] A method of digitizing in which the digitizer selects particular points, or vertices, to encode.

[ESRI software] In Survey Analyst, a visual indicator, after each keystroke, of whether or not a point with the typed name already exists in the survey dataset.

[ESRI software] In Survey Analyst, a unique part of every survey project. Points have a common name space across all projects of a survey dataset. However, different points in different … Read more

[graphics map display] A unit of measure for fonts, nearly equal to 1/72 of an inch.

[3D GIS] Act of reducing point data in a dataset. Point thinning reduces the number of point measurements needed to represent a surface for a given area.

[spatial analysis] A spatial operation in which points from one feature dataset are overlaid on the polygons of another to determine which points are contained within the polygons.

[map projections] A planar projection with its central point located at either the north or south pole.

A satellite orbit with an inclination near 90 degrees that passes over each polar region.

[geodesy] The distance from the earth’s geometric center to either pole.

1 [data models] On a map, a closed shape defined by a connected sequence of x,y coordinate pairs, where the first and last coordinate pair are the same and all … Read more

1 [data models] A map feature that bounds an area at a given scale, such as a country on a world map or a district on a city map. 2 … Read more

[data editing] The process of superimposing two or more geographic polygon layers and their attributes to produce a new polygon layer.

[data models] In a polygon coverage, the list of topologically connected arcs that define the boundary of a polygon feature and the label point that links it to an attribute … Read more

A three-dimensional object or volume defined by a number of plane faces or polygons.