GIS Glossary/W

GIS Glossary

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W3C
Acronym for World Wide Web Consortium. An organization that develops standards for the World Wide Web and promotes interoperability between Web technologies, such as browsers, programming languages, and devices. Members from around the world contribute to standards for XML, SOAP, HTML, and many other Web-based protocols.

wait time
The amount of time between the time that a client requests an object from a server and the time the client receives that object.

walk mode
In ArcGlobe, a navigation mode that allows navigation on a globe close to the ground, simulating walking.

WAN
Acronym for wide area network. A computer network that connects computers in a large area, such as in different cities or countries. The Internet is the most well-known example of a WAN.

war fighting element
In MOLE, a real-world battle element, such as a ground force unit or a lane boundary, represented by MOLE symbols on a map.

war fighting symbol
In MOLE, graphics on a map that represent battle elements such as ground troops and direction of troops. These graphics are used to plan and execute military operations in support of C4I functions. MOLE symbols fall within four main categories: force elements, tactical graphics, stacks, and leaders.

warping
A procedure for adjusting the coordinates of all the data points in a dataset to allow a more accurate match between known locations and a few data points within the dataset. Rubber sheeting preserves the interconnectivity between points and objects through stretching, shrinking, or reorienting their interconnecting lines.

watch file
A text file that records all dialog during an ArcInfo session. Watch files can be edited and converted to macro programs.

waterfall model
A software design methodology in which development proceeds through a top-down process of overlapping stages. First proposed in 1970, the waterfall model is a highly structured approach to a project life cycle that cascades linearly through the developmental phases of requirements analysis, design, implementation, testing, integration, and maintenance.

watershed
A basin-like terrestrial region consisting of all the land that drains water into a common terminus.

wavelength
The distance between two successive crests on a wave, calculated as the velocity of the wave divided by its frequency.

wavelet compression
A lossy method of data compression that uses mathematical functions and is best used in image or sound compression.

wayfinding
The mental activities engaged in by a person trying to reach a destination, usually an unfamiliar one, in real or virtual space. Wayfinding consists of acquiring information that is relevant to choosing a route, or a segment of a route, and of evaluating that information in the course of travel so the route can be changed as needed. Wayfinding is the cognitive component of navigation.

waypoint
A location of interest, or a reference point on a route, stored as latitude-longitude coordinates and often captured by a GPS receiver.

WCS
Acronym for Web Coverage Service. A standard specification for exchanging coverages over the Internet using a server. The Web Coverage Service (WCS) is the result of a collaborative effort assembled by the Open Geospatial Consortium, Inc. (OGC).

Web application
A software program that communicates via the World Wide Web and delivers Web-based information to the user in HTML format. Web applications are typically used to add customization and interactivity to Web pages. Web applications may also be called Web-based applications.

Web application template
A file that contains a user interface as well as all the code and necessary files to use as a starting point for creating a new customized Web application. ArcGIS Server contains a number of Web application templates.

Web browser
An application that allows users to access and view Web pages on their computer screens. Web browsers enable users to view HTML documents on the World Wide Web.

Web control
The visual component of a Web form that executes its own action on the server. Web controls are designed specifically to work on Web forms and are similar in appearance to HTML elements.

Web Coverage Service
A standard specification for exchanging coverages over the Internet using a server. The Web Coverage Service (WCS) is the result of a collaborative effort assembled by the Open Geospatial Consortium, Inc. (OGC)

Web Feature Server specification
A set of interface specifications that standardizes data manipulation and map display on the Internet. The Web Feature Server (WFS) specification is the result of a collaborative effort assembled by the Open Geospatial Consortium, Inc. (OGC).

Web form
Based on ASP.NET technology, Web forms allow the creation of dynamic Web pages in a Web application. Web forms present their user interface to a client in a Web browser or other device, but generally execute their actions on the server.

Web Map Server specification
A set of interface specifications that provides uniform access by Web clients to maps rendered by map servers on the Internet. The Web Map Server (WMS) is the result of a collaborative effort assembled by the Open Geospatial Consortium, Inc. (OGC).

Web page
A page of information stored on a Web site and viewed in a Web browser. Web pages may contain text, graphics, animations, forms for data entry, and links to other Web pages.

Web portal
A Web resource that provides access to a broad array of related resources and services.

Web server
A computer that manages Web documents, Web applications, and Web services and makes them available to the rest of the world.

Web service
A software component accessible over the World Wide Web for use in other applications. Web services are built using industry standards such as XML and SOAP, and thus are not dependent on any particular operating system or programming language, allowing access to them through a wide range of applications.

Web service catalog
A collection of ArcGIS Server Web services. A Web service catalog is itself a Web service with a distinct location (URL) and can be queried to obtain the list of Web services in the catalog and their URLs.

Web Service Description Language
An XML format for describing the methods, types, and connection point of a SOAP Web service.

Web site
A collection of Web pages (HTML files) that are interconnected with hyperlinks and published on the World Wide Web.

weed tolerance
The minimum distance allowed between any two vertices along a line, set before digitizing. When new lines are added, vertices that fall within that distance of the last vertex are ignored. Weed tolerance applies only to vertices, not to nodes.

weeding
Reducing the number of points that define a line while preserving its essential shape.

weight
A number that indicates the importance of a variable for a particular calculation. The larger the weight assigned to the variable, the more that variable will influence the outcome of the operation.

weight filter
In geometric networks, a specification for which network features can be traced based on their weight values.

weighted constrained adjustment
In Survey Analyst for field measurements, one of two possibilities for performing a constrained adjustment. In the weighted constrained adjustment, the reference point coordinates are treated as observed measurements and their standard deviations are applied in the adjustment.

weighted mean center
The geographic center of a set of points as adjusted for the influence of a value associated with each point. For example, while the mean center of a group of grocery stores would be the location obtained by averaging the stores' x,y coordinates, the weighted mean center would be shifted closer to stores with higher sales, more square footage, or a greater quantity of some other specified attribute.

weighted moving average
The value of a point's attribute computed by averaging the values of its surrounding points, taking into account their importance or their distance from the point.

weighted overlay
A technique for combining multiple rasters by applying a common measurement scale of values to each raster, weighting each according to its importance, and adding them together to create an integrated analysis.

weird polygon
A polygon that violates topological integrity by crossing its own boundary (usually by making a small loop).

WFS
A set of interface specifications that standardizes data manipulation and map display on the Internet. The Web Feature Server (WFS) specification is the result of a collaborative effort assembled by the Open Geospatial Consortium, Inc. (OGC).

WGS 1972
Acronym for World Geodetic System 1972. A geocentric datum and coordinate system designed by the U.S. Department of Defense, no longer in use.

WGS 1984
Acronym for World Geodetic System 1984. The most widely used geocentric datum and geographic coordinate system today, designed by the U.S. Department of Defense to replace WGS72. GPS measurements are based on WGS84.

WGS72
Acronym for World Geodetic System 1972. A geocentric datum and coordinate system designed by the U.S. Department of Defense, no longer in use.

WGS84
Acronym for World Geodetic System 1984. The most widely used geocentric datum and geographic coordinate system today, designed by the U.S. Department of Defense to replace WGS72. GPS measurements are based on WGS84.

WHERE clause
A SQL clause that specifies a selection criterion that allows filtering of a query result set.

whisk broom scanner
A remote-sensing tool with an oscillating mirror that moves back and forth across a satellite's direction of travel, creating scan line strips that are contiguous or that overlap slightly, thereby producing an image.

wide area network
A computer network that connects computers in a large area, such as in different cities or countries. The Internet is the most well-known example of a WAN.

widget
An interactive graphic component of a user interface (such as a button, scroll bar, or menu bar), its controlling program, or the combination of both the component and program.

wind rose
A diagram showing, for a given place and time period, how much of the time the wind blows from each direction. Wind roses have many variations, but in the typical pattern, a number of wedges (usually eight, twelve, or sixteen) radiate from the center of a circle. The width and orientation of a wedge represent the direction from which the wind blows; the length of a wedge represents the percentage of time the wind blows from that direction. More complex wind roses use color schemes and other graphic devices to represent wind speed and related information.

windowing
The process of limiting the viewable extent of a map or data by panning and zooming.

wireframe
A three-dimensional picture of an object, composed entirely of lines (wires). The lines represent the edges or surface contours, including those that would otherwise be hidden by a solid view. Wireframes make editing easier, since the screen redraws much more quickly.

wireless application
A ready-to-use Web application for a wireless client such as a handheld device, PDA, or cellular phone, designed for a specific purpose such as maps and routing for travel assistance.

Wireless Location Web Service
A SOAP ArcWeb service that determines the location of wireless devices.

wizard
An interactive user interface that helps a software user complete a task one step at a time. Wizards are often implemented as a sequence of dialog boxes that the user can move through, filling in required details. Wizards are usually used to simplify long, difficult, or complex tasks.

WMS
A set of interface specifications that provides uniform access by Web clients to maps rendered by map servers on the Internet. The Web Map Server (WMS) is the result of a collaborative effort assembled by the Open Geospatial Consortium, Inc. (OGC).

word abbreviation
A shortened form of a word or phrase which represents the whole. Abbreviations are commonly a letter or group of letters taken from the complete form of the word, such as the usage of St.</I> in place of Street</I>.

work order
One specific task that proceeds through each stage of an organization's workflow process, including design, acceptance, and construction in the field.

workflow
An organization's established processes for design, construction, and maintenance of programs, products, and business objectives.

workgroup geodatabase
A Microsoft SQL Server Express database that uses ArcSDE technology to store, query, and modify spatial data. Workgroup geodatabases accept up to 10 non-Web client connections and unlimited Web client connections to the SQL Server Express instance and are licensed through ArcGIS Server Workgroup edition.

working directory
A directory that indicates the appropriate location on disk to place results from analysis.

workspace
A container for geographic data. A workspace can be a folder that contains shapefiles, a geodatabase, a feature dataset, or an ArcInfo workspace. Other multidimensional data formats such as netCDF or HDF can also be considered workspaces, and are often treated in this manner within GIS software packages.

workstation
A computer that has better graphics capabilities and more processing power than most personal computers, and is able to carry out several tasks at once. Workstations usually share data and software with other computers in a network.

world file
A text file containing information about where an image should be displayed in real-world coordinates. When an image has a properly configured world file, GIS software can use the information (a total of six values, including the starting coordinates, the cell size in both x- and y-dimensions, and any rotation and scaling information) to accurately overlay the image with any other data already in a projected or geographic coordinate system.

World Geodetic System 1972
A geocentric datum and coordinate system designed by the U.S. Department of Defense, no longer in use.

World Geodetic System 1984
Acronym for World Geodetic System 1984</I>. The most widely used geocentric datum and geographic coordinate system today, designed by the U.S. Department of Defense to replace WGS72. GPS measurements are based on WGS84.

World Wide Web
A worldwide, decentralized, public information space for sharing documents and conducting business on the Internet. Components of the World Wide Web include information in the form of HTML documents; identification tags (URLs) for the millions of computers that host this information; a set of technical specifications, called HTTP, for sending information from one computer to another; and Web browser software for accessing and displaying information.

World Wide Web Consortium
Acronym for World Wide Web Consortium</I>. An organization that develops standards for the World Wide Web and promotes interoperability between Web technologies, such as browsers, programming languages, and devices. Members from around the world contribute to standards for XML, SOAP, HTML, and many other Web-based protocols.

WSDL
Acronym for Web Service Description Language</I>. An XML format for describing the methods, types, and connection point of a SOAP Web service.

W-test
A type of statistical test used in surveying to detect blunders in a measurement network. The W-test is based on the assumption that the null hypothesis is rejected due to a gross error in one of the measurements and uses an alternative hypothesis to identify the erroneous measurement.

WYSIWYG
In ArcGIS desktop, this term refers to the editing tools providing visual feedback of the desired end result of an editing operation while the process is still underway. For Cartographic Representations, this is the ability to see a symbolized version of the feature being operated on instead of a wireframe version of the underlying geometry of the feature.