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Encyclopedia > Geographic Information System

A geographic information system (GIS), also known as a geographical information system or geospatial information system, is any system for capturing, storing, analyzing and managing data and associated attributes which are spatially referenced to Earth. In certain countries such as Canada, GIS is more well known as Geomatics. GIS can refer to: Geographic information system. ... This article is about Earth as a planet. ... Survey equipment used in geomatics Geomatics is the discipline of gathering, storing, processing, and delivering of geographic information, or spatially referenced information. ...


In the strictest sense, it is any information system capable of integrating, storing, editing, analyzing, sharing, and displaying geographically referenced information. In a more generic sense, GIS is a tool that allows users to create interactive queries (user created searches), analyze the spatial information, edit data, maps, and present the results of all these operations. Geographic information science is the science underlying the geographic concepts, applications and systems, taught in degree and GIS Certificate programs at many universities. Information System (example) An Information System (IS) is the system of persons, data records and activities that process the data and information in a given organization, including manual processes or automated processes. ... To georeference something is used to define its existence in physical space. ... The word space has many meanings, including: Physics The definition of space in physics is contentious. ... ‘Truth, as in a single, incontrovertible and correct fact, simply does not exist for much geographical information’ (Comber et al. ...


Geographic information system technology can be used for scientific investigations, resource management, asset management, environmental impact assessment, urban planning, cartography, criminology, history, sales, marketing, and logistics. For example, GIS might allow emergency planners to easily calculate emergency response times in the event of a natural disaster, GIS might be used to find wetlands that need protection from pollution, or GIS can be used by a company to site a new business location to take advantage of a previously underserved market. A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... This article is confusing for some readers, and needs to be edited for clarity. ... Asset management is the method that a company uses to track fixed assets, for example factory equipment, desks and chairs, computers, even buildings. ... An Environmental Impact Statement (EIS) is an assessment of the likely influence a project may have on the environment. ... Urban planning is concerned with the ordering and design of settlements, from the smallest towns to the worlds largest cities. ... Cartography or mapmaking (in Greek chartis = map and graphein = write) is the study and practice of making maps or globes. ... Criminology is the scientific study of crime as an individual and social phenomenon. ... A Historical GIS is a Geographical Information System that may display, store and analyze data of past geographies and track changes in time. ... Sales are the activities involved in providing products or services in return for money or other compensation. ... Next big thing redirects here. ... Look up Logistics in Wiktionary, the free dictionary. ... Mount Pinatubo eruption, 1991 A natural disaster is according to or provided by nature. ... A subtropical wetland in Florida, USA, with an endangered American Crocodile. ... Air pollution Pollution is the introduction of pollutants (whether chemical substances, or energy such as noise, heat, or light) into the environment to such a point that its effects become harmful to human health, other living organisms, or the environment. ... Look up Market in Wiktionary, the free dictionary. ...

Contents

History of development

About 15,500 years ago [1], on the walls of caves near Lascaux, France, Cro-Magnon hunters drew pictures of the animals they hunted.[2] Associated with the animal drawings are track lines and tallies thought to depict migration routes. While simplistic in comparison to modern technologies, these early records mimic the two-element structure of modern geographic information systems, an image associated with attribute information.[3] Cave painting at Lascaux. ... For the avant garde collective, see Cromagnon (band). ... Look up attribute in Wiktionary, the free dictionary. ...


Possibly the earliest use of the geographic method, in 1854 John Snow depicted a cholera outbreak in London using points to represent the locations of some individual cases.[4] His study of the distribution of cholera led to the source of the disease, a contaminated water pump within the heart of the cholera outbreak. Dr. John Snow John Snow (16 March 1813 – 16 June 1858) was a British physician and a leader in the adoption of anaesthesia and medical hygiene. ... Distribution of cholera Cholera, sometimes known as Asiatic cholera or epidemic cholera, is an infectious gastroenteritis caused by the bacterium Vibrio cholerae. ...

E. W. Gilbert's version (1958) of John Snow's 1855 map of the Soho cholera outbreak showing the clusters of cholera cases in the London epidemic of 1854
E. W. Gilbert's version (1958) of John Snow's 1855 map of the Soho cholera outbreak showing the clusters of cholera cases in the London epidemic of 1854

While the basic elements of topology and theme existed previously in cartography, the John Snow map was unique, using cartographic methods not only to depict but also to analyze clusters of geographically dependent phenomena for the first time. Image File history File links Download high resolution version (889x869, 248 KB)The original map drawn by Dr. John Snow (1813-1858), a British physician who is one of the founders of medical epidemiology, showing cases of cholera in the London epidemics of 1854, clustered around the locations of water... Image File history File links Download high resolution version (889x869, 248 KB)The original map drawn by Dr. John Snow (1813-1858), a British physician who is one of the founders of medical epidemiology, showing cases of cholera in the London epidemics of 1854, clustered around the locations of water... Dr. John Snow John Snow (16 March 1813 – 16 June 1858) was a British physician and a leader in the adoption of anaesthesia and medical hygiene. ... Distribution of cholera Cholera, sometimes known as Asiatic cholera or epidemic cholera, is an infectious gastroenteritis caused by the bacterium Vibrio cholerae. ... This article is about the capital of England and the United Kingdom. ... A Möbius strip, an object with only one surface and one edge; such shapes are an object of study in topology. ... Cartography or mapmaking (in Greek chartis = map and graphein = write) is the study and practice of making maps or globes. ...


The early 20th century saw the development of "photo lithography" where maps were separated into layers. Computer hardware development spurred by nuclear weapon research would lead to general purpose computer "mapping" applications by the early 1960s.[5] The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 kilometers (11 mi) above the hypocenter A nuclear weapon derives its destructive force from nuclear reactions of fusion or fission. ...


The year 1962 saw the development of the world's first true operational GIS in Ottawa, Ontario, Canada by the federal Department of Forestry and Rural Development. Developed by Dr. Roger Tomlinson, it was called the "Canada Geographic Information System" (CGIS) and was used to store, analyze, and manipulate data collected for the Canada Land Inventory (CLI)—an initiative to determine the land capability for rural Canada by mapping information about soils, agriculture, recreation, wildlife, waterfowl, forestry, and land use at a scale of 1:50,000. A rating classification factor was also added to permit analysis. This article is about the capital city of Canada. ... Dr. Roger Tomlinson is one of the primary originators of modern computerized Geographic Information Systems. ... The Canada Geographic Information System (CGIS) was developed in the 1950s and 1960s to assist in regulatory procedures of land-use management and resource monitoring. ... The Canada Land Inventory is a survey of soil capability performed in the farming areas of Canada. ...


CGIS was the world's first "system" and was an improvement over "mapping" applications as it provided capabilities for overlay, measurement, and digitizing/scanning. It supported a national coordinate system that spanned the continent, coded lines as "arcs" having a true embedded topology, and it stored the attribute and locational information in separate files. As a result of this, Tomlinson has become known as the "father of GIS," particularly for his use of overlays in promoting the spatial analysis of convergent geographic data.[6] CGIS lasted into the 1990s and built the largest digital land resource database in Canada. It was developed as a mainframe based system in support of federal and provincial resource planning and management. Its strength was continent-wide analysis of complex data sets. The CGIS was never available in a commercial form. Digitizing, or digitization, is the process of turning an analog signal into a digital representation of that signal. ... A data set (or dataset) is a collection of data, usually presented in tabular form. ...


In 1964, Howard T Fisher formed the Laboratory for Computer Graphics and Spatial Analysis at the Harvard Graduate School of Design (LCGSA 1965-1991), where a number of important theoretical concepts in spatial data handling were developed, and which by the 1970s had distributed seminal software code and systems, such as 'SYMAP', 'GRID', and 'ODYSSEY' -- which served as literal and inspirational sources for subsequent commercial development -- to universities, research centers, and corporations worldwide.[7]


By the early 1980s, M&S Computing (later Intergraph), Environmental Systems Research Institute (ESRI) and CARIS emerged as commercial vendors of GIS software, successfully incorporating many of the CGIS features, combining the first generation approach to separation of spatial and attribute information with a second generation approach to organizing attribute data into database structures. In parallel, the development of a public domain GIS was begun in 1982 by the U.S. Army Corp of Engineering Research Laboratory (USA-CERL) in Champaign, Illinois, a branch of the U.S. Army Corps of Engineers to meet the need of the United States military for software for land management and environmental planning. The later 1980s and 1990s industry growth were spurred on by the growing use of GIS on Unix workstations and the personal computer. By the end of the 20th century, the rapid growth in various systems had been consolidated and standardized on relatively few platforms and users were beginning to export the concept of viewing GIS data over the Internet, requiring data format and transfer standards. More recently, there is a growing number of free, open source GIS packages which run on a range of operating systems and can be customized to perform specific tasks. Intergraph was founded in 1969 as M&S Computing, Inc. ... For the Irish research group, see Economic and Social Research Institute. ... CARIS is the abbreviation of Computer Aided Resource Information System, a company based in Fredericton, New Brunswick which produces GIS and hydrographic data processing software. ... GRASS (Geographic Resources Analysis Support System) is an open source, Free Software Geographical information system (GIS) with raster, topological vector, image processing, and graphics production functionality that operates on various platforms through a graphical user interface and shell in the X Window System. ... Filiation of Unix and Unix-like systems Unix (officially trademarked as UNIX®, sometimes also written as or ® with small caps) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. ...


Techniques used in GIS

Data creation

Modern GIS technologies use digital information, for which various digitized data creation methods are used. The most common method of data creation is digitization, where a hard copy map or survey plan is transferred into a digital medium through the use of a computer-aided design (CAD) program, and geo-referencing capabilities. With the wide availability of ortho-rectified imagery (both from satellite and aerial sources), heads-up digitizing is becoming the main avenue through which geographic data is extracted. Heads-up digitizing involves the tracing of geographic data directly on top of the aerial imagery instead of through the traditional method of tracing the geographic form on a separate digitizing tablet. CADD and CAD redirect here. ...


Relating information from different sources

If you could relate information about the rainfall of your state to aerial photographs of your county, you might be able to tell which wetlands dry up at certain times of the year. A GIS, which can use information from many different sources in many different forms, can help with such analyses. The primary requirement for the source data consists of knowing the locations for the variables. Location may be annotated by x, y, and z coordinates of longitude, latitude, and elevation, or by other geocode systems like ZIP Codes or by highway mile markers. Any variable that can be located spatially can be fed into a GIS. Several computer databases that can be directly entered into a GIS are being produced by government agencies and non-government organizations[citation needed]. Different kinds of data in map form can be entered into a GIS. Image File history File links Gnome-globe. ... For other uses, see State (disambiguation). ... A county is generally a sub-unit of regional self-government within a sovereign jurisdiction. ... Longitude is the east-west geographic coordinate measurement most commonly utilized in cartography and global navigation. ... This article is about the geographical term. ... For other uses of the word, see Elevation In geography, the elevation of a geographic location is its height above mean sea level (or possibly some other fixed point). ... A geocode is a geographical code to identify a point or area at the surface of the earth. ... Mr. ... A milestone A milestone is one of a series of numbered markers placed along a road at regular intervals, typically at the side of the road or in a median. ... This article is about computing. ...


A GIS can also convert existing digital information, which may not yet be in map form, into forms it can recognize and use. For example, digital satellite images generated through remote sensing can be analyzed to produce a map-like layer of digital information about vegetative covers. Another fairly developed resource for naming GIS objects is the Getty Thesaurus of Geographic Names (GTGN), which is a structured vocabulary containing around 1,000,000 names and other information about places[1]. Wikipedia does not yet have an article with this exact name. ... For the purported psychic ability to sense remotely, see Remote viewing right Synthetic aperture radar image of Death Valley colored using polarimetry In the broadest sense, remote sensing is the short or large-scale acquisition of information of an object or phenomenon, by the use of either recording or real... Layer may refer to: Look up Layer in Wiktionary, the free dictionary. ... The Getty Thesaurus of Geographic Names (abbreviated Getty TGN or GTGN) is a product of the J. Paul Getty Trust included in the Getty Vocabulary Program[1]. The Thesaurus includes names and other information about places such as cities, counties, nations and their associated physical features like mountains, coasts and... The Getty Thesaurus of Geographic Names (abbreviated Getty TGN or GTGN) is a product of the J. Paul Getty Trust included in the Getty Vocabulary Program[1]. The Thesaurus includes names and other information about places such as cities, counties, nations and their associated physical features like mountains, coasts and...


Likewise, census or hydrologic tabular data can be converted to map-like form, serving as layers of thematic information in a GIS. Image:1870 census Lindauer Weber 01. ...


Data representation

GIS data represents real world objects (roads, land use, elevation) with digital data. Real world objects can be divided into two abstractions: discrete objects (a house) and continuous fields (rain fall amount or elevation). There are two broad methods used to store data in a GIS for both abstractions: Raster and Vector. For other uses, see Data (disambiguation). ...


Raster

A raster data type is, in essence, any type of digital image. Anyone who is familiar with digital photography will recognize the pixel as the smallest individual unit of an image. A combination of these pixels will create an image, distinct from the commonly used scalable vector graphics which are the basis of the vector model. While a digital image is concerned with the output as representation of reality, in a photograph or art transferred to computer, the raster data type will reflect an abstraction of reality. Aerial photos are one commonly used form of raster data, with only one purpose, to display a detailed image on a map or for the purposes of digitization. Other raster data sets will contain information regarding elevation, a DEM, or reflectance of a particular wavelength of light, LANDSAT. Imagine the smiley face in the top left corner as an RGB bitmap image. ... SVG redirects here. ... 3D rendering of a DEM of Tithonium Chasma on Mars A digital elevation model (DEM) is a digital representation of ground surface topography or terrain. ... The Landsat program is the longest running enterprise for acqusition of imagery of Earth from space. ...

Digital elevation model, map (image), and vector data
Digital elevation model, map (image), and vector data

Raster data type consists of rows and columns of cells, with each cell storing a single value. Raster data can be images (raster images) with each pixel (or cell) containing a color value. Additional values recorded for each cell may be a discrete value, such as land use, a continuous value, such as temperature, or a null value if no data is available. While a raster cell stores a single value, it can be extended by using raster bands to represent RGB (red, green, blue) colors, colormaps (a mapping between a thematic code and RGB value), or an extended attribute table with one row for each unique cell value. The resolution of the raster data set is its cell width in ground units. Image File history File links Geabios3d. ... A bit array (or bitmap, in some cases) is an array data structure which compactly stores individual bits (boolean values). ... Imagine the smiley face in the top left corner as an RGB bitmap image. ...


Raster data is stored in various formats; from a standard file-based structure of TIF, JPEG, etc. to binary large object (BLOB) data stored directly in a relational database management system (RDBMS) similar to other vector-based feature classes. Database storage, when properly indexed, typically allows for quicker retrieval of the raster data but can require storage of millions of significantly-sized records. A blob is a collection of binary data stored as a single entity in a database management system. ... A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. ...


Vector

A simple vector map, using each of the vector elements: points for wells, lines for rivers, and a polygon for the lake.
A simple vector map, using each of the vector elements: points for wells, lines for rivers, and a polygon for the lake.

In a GIS, geographical features are often expressed as vectors, by considering those features as geometrical shapes. Different geographical features are expressed by different types of geometry: Image File history File links Simple_vector_map. ... Image File history File links Simple_vector_map. ... Geometry (from the Greek words Ge = earth and metro = measure) is the branch of mathematics first introduced by Theaetetus dealing with spatial relationships. ...

Points
Zero-dimensional points are used for geographical features that can best be expressed by a single point reference; in other words, simple location. For example, the locations of wells, peak elevations, features of interest or trailheads. Points convey the least amount of information of these file types. Points can also be used to represent areas when displayed at a small scale. For example, cities on a map of the world would be represented by points rather than polygons. No measurements are possible with point features.
Lines or polylines
One-dimensional lines or polylines are used for linear features such as rivers, roads, railroads, trails, and topographic lines. Again, as with point features, linear features displayed at a small scale will be represented as linear features rather than as a polygon. Line features can measure distance.
Polygons
Two-dimensional polygons are used for geographical features that cover a particular area of the earth's surface. Such features may include lakes, park boundaries, buildings, city boundaries, or land uses. Polygons convey the most amount of information of the file types. Polygon features can measure perimeter and area.

Each of these geometries is linked to a row in a database that describes their attributes. For example, a database that describes lakes may contain a lake's depth, water quality, pollution level. This information can be used to make a map to describe a particular attribute of the dataset. For example, lakes could be coloured depending on level of pollution. Different geometries can also be compared. For example, the GIS could be used to identify all wells (point geometry) that are within 1-mile (1.6 km) of a lake (polygon geometry) that has a high level of pollution. A spatial point is an entity with a location in space but no extent (volume, area or length). ... Look up line in Wiktionary, the free dictionary. ... Look up polygon in Wiktionary, the free dictionary. ...


Vector features can be made to respect spatial integrity through the application of topology rules such as 'polygons must not overlap'. Vector data can also be used to represent continuously varying phenomena. Contour lines and triangulated irregular networks (TIN) are used to represent elevation or other continuously changing values. TINs record values at point locations, which are connected by lines to form an irregular mesh of triangles. The face of the triangles represent the terrain surface. Contour and Contour map redirect here. ... A Triangulated Irregular Network (TIN) is a digital data structure used in a geographic information system (GIS) for the representation of a surface. ... Elevation histogram of the surface of the Earth – approximately 71% of the Earths surface is covered with water. ...


Advantages and disadvantages

There are advantages and disadvantages to using a raster or vector data model to represent reality. Raster data sets record a value for all points in the area covered which may require more storage space than representing data in a vector format that can store data only where needed. Raster data also allows easy implementation of overlay operations, which are more difficult with vector data. Vector data can be displayed as vector graphics used on traditional maps, whereas raster data will appear as an image that, depending on the resolution of the raster file, may have a blocky appearance for object boundaries. Vector data can be easier to register, scale, and re-project. This can simplify combining vector layers from different sources. Vector data are more compatible with relational database environment. They can be part of a relational table as a normal column and processes using a multitude of operators. Example showing effect of vector graphics versus raster graphics. ... Look up image in Wiktionary, the free dictionary. ...


The file size for vector data is usually much smaller for storage and sharing than raster data. Image or raster data can be 10 to 100 times larger than vector data depending on the resolution. Another advantage of vector data is it can be easily updated and maintained. For example, a new highway is added. The raster image will have to be completely reproduced, but the vector data, "roads," can be easily updated by adding the missing road segment. In addition, vector data allow much more analysis capability especially for "networks" such as roads, power, rail, telecommunications, etc. For example, with vector data attributed with the characteristics of roads, ports, and airfields, allows the analyst to query for the best route or method of transportation. In the vector data, the analyst can query the data for the largest port with an airfield within 60 miles and a connecting road that is at least two lane highway. Raster data will not have all the characteristics of the features it displays.


Voxel

Selected GIS additionally support the voxel data model. A voxel (a portmanteau of the words volumetric and pixel) is a volume element, representing a value on a regular grid in three dimensional space. This is analogous to a pixel, which represents 2D image data. Voxels can be interpolated from 3D point clouds (3D point vector data), or merged from 2D raster slices. A voxel (a portmanteau of the words volumetric and pixel) is a volume element, representing a value on a regular grid in three dimensional space. ... A portmanteau (IPA: ) is a word or morpheme that fuses two or more words or word parts to give a combined or loaded meaning. ... Example of regular grid. ... This article is about process of creating 3D computer graphics. ... This article is about the picture element. ... 2D computer graphics is the computer-based generation of digital images—mostly from two-dimensional models (such as 2D geometric models, text, and digital images) and by techniques specific to them. ...


Non-spatial data

Additional non-spatial data can also be stored besides the spatial data represented by the coordinates of a vector geometry or the position of a raster cell. In vector data, the additional data are attributes of the object. For example, a forest inventory polygon may also have an identifier value and information about tree species. In raster data the cell value can store attribute information, but it can also be used as an identifier that can relate to records in another table. This article is about the data structure. ...


There is also software being developed to support spatial and non-spatial decision-making. In this software, the solutions to spatial problems are integrated with solutions to non-spatial problems. The end result it is hoped with these Flexible Spatial Decision-Making Support Systems (FSDSS)[8] will be that non experts can use GIS and spatial criteria with their other non spatial criteria to view solutions to multi-criteria problems that will support decision making.


Data capture

Data capture—entering information into the system—consumes much of the time of GIS practitioners. There are a variety of methods used to enter data into a GIS where it is stored in a digital format.


Existing data printed on paper or PET film maps can be digitized or scanned to produce digital data. A digitizer produces vector data as an operator traces points, lines, and polygon boundaries from a map. Scanning a map results in raster data that could be further processed to produce vector data. Biaxially-oriented polyethylene terephthalate (boPET) polyester film is used for its high tensile strength, chemical and dimensional stability, transparency, gas and aroma barrier properties and electrical insulation. ... In telecommunication and computing, the term digitizer has the following meanings: A device that converts an analog signal into a digital representation of the analog signal. ... In computing, a scanner is a device that analyzes images, printed text, or handwriting, or an object (such as an ornament) and converts it to a digital image. ...


Survey data can be directly entered into a GIS from digital data collection systems on survey instruments using a technique called Coordinate Geometry (COGO). Positions from a Global Positioning System (GPS), another survey tool, can also be directly entered into a GIS. Surveyor at work with a leveling instrument. ... Analytic geometry, also called coordinate geometry and earlier referred to as Cartesian geometry or analytical geometry, is the study of geometry using the principles of algebra. ... GPS redirects here. ...


Remotely sensed data also plays an important role in data collection and consist of sensors attached to a platform. Sensors include cameras, digital scanners and LIDAR, while platforms usually consist of aircraft and satellites. For the purported psychic ability to sense remotely, see Remote viewing right Synthetic aperture radar image of Death Valley colored using polarimetry In the broadest sense, remote sensing is the short or large-scale acquisition of information of an object or phenomenon, by the use of either recording or real... For other uses, see Camera (disambiguation). ... A FASOR used at the Starfire Optical Range for LIDAR and laser guide star experiments is tuned to the sodium D2a line and used to excite sodium atoms in the upper atmosphere. ... This article is about artificial satellites. ...


The majority of digital data currently comes from photo interpretation of aerial photographs. Soft copy workstations are used to digitize features directly from stereo pairs of digital photographs. These systems allow data to be captured in 2 and 3 dimensions, with elevations measured directly from a stereo pair using principles of photogrammetry. Currently, analog aerial photos are scanned before being entered into a soft copy system, but as high quality digital cameras become cheaper this step will be skipped. The Georgian terrace of Royal Crescent (Bath, England) from a hot air balloon Intersection of E42 and E451 from an aircraft soon after takeoff from Frankfurt International Airport Moreton Island in Queensland, Australia Aerial photography is the taking of photographs of the ground while not supported by a ground-based... Stereo card image modified for crossed eye viewing. ... Photogrammetry is a remote sensing technology in which geometric properties about objects are determined from photographic images. ...


Satellite remote sensing provides another important source of spatial data. Here satellites use different sensor packages to passively measure the reflectance from parts of the electromagnetic spectrum or radio waves that were sent out from an active sensor such as radar. Remote sensing collects raster data that can be further processed using different bands to identify objects and classes of interest, such as land cover. Although some radiations are marked as N for no in the diagram, some waves do in fact penetrate the atmosphere, although extremely minimally compared to the other radiations The electromagnetic (EM) spectrum is the range of all possible electromagnetic radiation. ... For other uses, see Radar (disambiguation). ...


When data is captured, the user should consider if the data should be captured with either a relative accuracy or absolute accuracy, since this could not only influence how information will be interpreted but also the cost of data capture.


In addition to collecting and entering spatial data, attribute data is also entered into a GIS. For vector data, this includes additional information about the objects represented in the system.


After entering data into a GIS, the data usually requires editing, to remove errors, or further processing. For vector data it must be made "topologically correct" before it can be used for some advanced analysis. For example, in a road network, lines must connect with nodes at an intersection. Errors such as undershoots and overshoots must also be removed. For scanned maps, blemishes on the source map may need to be removed from the resulting raster. For example, a fleck of dirt might connect two lines that should not be connected.


Raster-to-vector translation

Data restructuring can be performed by a GIS to convert data into different formats. For example, a GIS may be used to convert a satellite image map to a vector structure by generating lines around all cells with the same classification, while determining the cell spatial relationships, such as adjacency or inclusion.


More advanced data processing can occur with image processing, a technique developed in the late 1960s by NASA and the private sector to provide contrast enhancement, false colour rendering and a variety of other techniques including use of two dimensional Fourier transforms. UPIICSA IPN - Binary image Image processing is any form of information processing for which the input is an image, such as photographs or frames of video; the output is not necessarily an image, but can be for instance a set of features of the image. ... For other uses, see NASA (disambiguation). ... The Fourier transform, named for Jean Baptiste Joseph Fourier, is an integral transform that re-expresses a function in terms of sinusoidal basis functions, i. ...


Since digital data are collected and stored in various ways, the two data sources may not be entirely compatible. So a GIS must be able to convert geographic data from one structure to another. Geographic data is about much more than electronic pictures of maps. ...


Projections, coordinate systems and registration

A property ownership map and a soils map might show data at different scales. Map information in a GIS must be manipulated so that it registers, or fits, with information gathered from other maps. Before the digital data can be analyzed, they may have to undergo other manipulations—projection and coordinate conversions, for example—that integrate them into a GIS. For other uses, see Map (disambiguation). ...


The earth can be represented by various models, each of which may provide a different set of coordinates (e.g., latitude, longitude, elevation) for any given point on the earth's surface. The simplest model is to assume the earth is a perfect sphere. As more measurements of the earth have accumulated, the models of the earth have become more sophisticated and more accurate. In fact, there are models that apply to different areas of the earth to provide increased accuracy (e.g., North American Datum, 1927 - NAD27 - works well in North America, but not in Europe). See Datum for more information. It has been suggested that this article or section be merged with Geodetic system. ...


Projection is a fundamental component of map making. A projection is a mathematical means of transferring information from a model of the Earth, which represents a three-dimensional curved surface, to a two-dimensional medium—paper or a computer screen. Different projections are used for different types of maps because each projection particularly suits certain uses. For example, a projection that accurately represents the shapes of the continents will distort their relative sizes. See Map projection for more information. Cartography or mapmaking (in Greek chartis = map and graphein = write) is the study and practice of making maps or globes. ... The Mercator projection shows courses of constant bearing as straight lines. ... The Mercator projection shows courses of constant bearing as straight lines. ...


Since much of the information in a GIS comes from existing maps, a GIS uses the processing power of the computer to transform digital information, gathered from sources with different projections and/or different coordinate systems, to a common projection and coordinate system. For images, this process is called rectification. Image rectification is a transformation process used to project multiple images onto a common image surface. ...


Spatial analysis with GIS

Data modeling

It is difficult to relate wetlands maps to rainfall amounts recorded at different points such as airports, television stations, and high schools. A GIS, however, can be used to depict two- and three-dimensional characteristics of the Earth's surface, subsurface, and atmosphere from information points. For example, a GIS can quickly generate a map with isopleth or contour lines that indicate differing amounts of rainfall. Contour and Contour map redirect here. ...


Such a map can be thought of as a rainfall contour map. Many sophisticated methods can estimate the characteristics of surfaces from a limited number of point measurements. A two-dimensional contour map created from the surface modeling of rainfall point measurements may be overlaid and analyzed with any other map in a GIS covering the same area.


Additionally, from a series of three-dimensional points, or digital elevation model, isopleth lines representing elevation contours can be generated, along with slope analysis, shaded relief, and other elevation products. Watersheds can be easily defined for any given reach, by computing all of the areas contiguous and uphill from any given point of interest. Similarly, an expected thalweg of where surface water would want to travel in intermittent and permanent streams can be computed from elevation data in the GIS. Thalweg (a German word compounded from Tal, valley, and Weg, way) is a term adopted into English usage for geography. ...


Topological modeling

In the past years, were there any gas stations or factories operating next to the swamp? Any within two miles (3 km) and uphill from the swamp? A GIS can recognize and analyze the spatial relationships that exist within digitally stored spatial data. These topological relationships allow complex spatial modelling and analysis to be performed. Topological relationships between geometric entities traditionally include adjacency (what adjoins what), containment (what encloses what), and proximity (how close something is to something else).


Networks

If all the factories near a wetland were accidentally to release chemicals into the river at the same time, how long would it take for a damaging amount of pollutant to enter the wetland reserve? A GIS can simulate the routing of materials along a linear network. Values such as slope, speed limit, or pipe diameter can be incorporated into network modeling in order to represent the flow of the phenomenon more accurately. Network modelling is commonly employed in transportation planning, hydrology modeling, and infrastructure modeling. Transportation planning is the field involved with the siting of transportation facilities (generally streets and highways and public transport lines). ... Water covers 70% of the Earths surface. ...


Cartographic modeling

An example of use of layers in a GIS application. In this example, the forest cover layer (light green) is at the bottom, with the topographic layer over it. Next up is the stream layer, then the boundary layer, then the road layer. The order is very important in order to properly display the final result. Note that the pond layer was located just below the stream layer, so that a stream line can be seen overlying one of the ponds.
An example of use of layers in a GIS application. In this example, the forest cover layer (light green) is at the bottom, with the topographic layer over it. Next up is the stream layer, then the boundary layer, then the road layer. The order is very important in order to properly display the final result. Note that the pond layer was located just below the stream layer, so that a stream line can be seen overlying one of the ponds.

The term "cartographic modeling" was (probably) coined by Dana Tomlin in his PhD dissertation and later in his book which has the term in the title. Cartographic modeling refers to a process where several thematic layers of the same area are produced, processed, and analyzed. Tomlin used raster layers, but the overlay method (see below) can be used more generally. Operations on map layers can be combined into algorithms, and eventually into simulation or optimization models. Image File history File links Size of this preview: 800 × 527 pixelsFull resolution‎ (997 × 657 pixels, file size: 300 KB, MIME type: image/jpeg) Example of layers used in GIS work. ... Image File history File links Size of this preview: 800 × 527 pixelsFull resolution‎ (997 × 657 pixels, file size: 300 KB, MIME type: image/jpeg) Example of layers used in GIS work. ...


Map overlay

The combination of two separate spatial data sets (points, lines or polygons) to create a new output vector data set. These overlays are similar to mathematical Venn diagram overlays. A union overlay combines the geographic features and attribute tables of both inputs into a single new output. An intersect overlay defines the area where both inputs overlap and retains a set of attribute fields for each. A symmetric difference overlay defines an output area that includes the total area of both inputs except for the overlapping area. A Venn diagram of sets A, B, and C Venn diagrams (or set diagrams) are illustrations used in the branch of mathematics known as set theory. ... In set theory and other branches of mathematics, the union of a collection of sets is the set that contains everything that belongs to any of the sets, but nothing else. ... In mathematics, the intersection of two sets A and B is the set that contains all elements of A that also belong to B (or equivalently, all elements of B that also belong to A), but no other elements. ... In mathematics, the symmetric difference of two sets is the set of elements which are in one of either set, but not in both. ...


Data extraction is a GIS process similar to vector overlay, though it can be used in either vector or raster data analysis. Rather than combining the properties and features of both data sets, data extraction involves using a "clip" or "mask" to extract the features of one data set that fall within the spatial extent of another data set.


In raster data analysis, the overlay of data sets is accomplished through a process known as "local operation on multiple rasters" or "map algebra," through a function that combines the values of each raster's matrix. This function may weigh some inputs more than others through use of an "index model" that reflects the influence of various factors upon a geographic phenomenon. In mathematics, a matrix (plural matrices) is a rectangular table of elements (or entries), which may be numbers or, more generally, any abstract quantities that can be added and multiplied. ...


Automated cartography

Digital cartography and GIS both encode spatial relationships in structured formal representations. GIS is used in digital cartography modeling as a (semi)automated process of making maps, so called Automated Cartography. In practice, it can be a subset of a GIS, within which it is equivalent to the stage of visualization, since in most cases not all of the GIS functionality is used. Cartographic products can be either in a digital or in a hardcopy format. Powerful analysis techniques with different data representation can produce high-quality maps within a short time period. The main problem in Automated Cartography is to use a single set of data to produce multiple products at a variety of scales, a technique known as Generalization. Visualization can refer to: Graphic Visualization as in any technique for creating images, diagrams, or animations to communicate any message. ... For the term in the context of mathematical logic, see Generalization (logic). ...


Geostatistics

Main article: Geostatistics

Geostatistics is a point-pattern analysis that produces field predictions from data points. It is a way of looking at the statistical properties of those special data. It is different from general applications of statistics because it employs the use of graph theory and matrix algebra to reduce the number of parameters in the data. Only the second-order properties of the GIS data are analyzed. This article or section is in need of attention from an expert on the subject. ... This article or section is in need of attention from an expert on the subject. ... This article is about the field of statistics. ... A drawing of a graph. ... In mathematics, a matrix (plural matrices) is a rectangular table of elements (or entries), which may be numbers or, more generally, any abstract quantities that can be added and multiplied. ...


When phenomena are measured, the observation methods dictate the accuracy of any subsequent analysis. Due to the nature of the data (e.g. traffic patterns in an urban environment; weather patterns over the Pacific Ocean), a constant or dynamic degree of precision is always lost in the measurement. This loss of precision is determined from the scale and distribution of the data collection.


To determine the statistical relevance of the analysis, an average is determined so that points (gradients) outside of any immediate measurement can be included to determine their predicted behavior. This is due to the limitations of the applied statistic and data collection methods, and interpolation is required in order to predict the behavior of particles, points, and locations that are not directly measurable.

Hillshade model derived from a Digital Elevation Model (DEM) of the Valestra area in the northern Apennines (Italy)
Hillshade model derived from a Digital Elevation Model (DEM) of the Valestra area in the northern Apennines (Italy)

Interpolation is the process by which a surface is created, usually a raster data set, through the input of data collected at a number of sample points. There are several forms of interpolation, each which treats the data differently, depending on the properties of the data set. In comparing interpolation methods, the first consideration should be whether or not the source data will change (exact or approximate). Next is whether the method is subjective, a human interpretation, or objective. Then there is the nature of transitions between points: are they abrupt or gradual. Finally, there is whether a method is global (it uses the entire data set to form the model), or local where an algorithm is repeated for a small section of terrain. ImageMetadata File history File links Download high resolution version (480x640, 101 KB) Demarest Hall seen from the outside during freshmen convication. ... ImageMetadata File history File links Download high resolution version (480x640, 101 KB) Demarest Hall seen from the outside during freshmen convication. ... For other uses, see Interpolation (disambiguation). ...


Interpolation is a justified measurement because of a Spatial Autocorrelation Principle that recognizes that data collected at any position will have a great similarity to, or influence of those locations within its immediate vicinity.


Digital elevation models (DEM), triangulated irregular networks (TIN), Edge finding algorithms, Theissen Polygons, Fourier analysis, Weighted moving averages, Inverse Distance Weighted, Moving averages, Kriging, Spline, and Trend surface analysis are all mathematical methods to produce interpolative data. 3D rendering of a DEM of Tithonium Chasma on Mars A digital elevation model (DEM) is a digital representation of ground surface topography or terrain. ... A Triangulated Irregular Network (TIN) is a digital data structure used in a geographic information system (GIS) for the representation of a surface. ... Fourier analysis, named after Joseph Fouriers introduction of the Fourier series, is the decomposition of a function in terms of a sum of sinusoidal basis functions (vs. ... A moving average, in finance and especially in technical analysis, is one of a family of similar statistical techniques used to analyze time series data. ... Kriging is group of geostatistical techniques to interpolate the value of a random field (e. ... One type of spline, a bézier curve In the mathematical subfield of numerical analysis, a spline is a special function defined piecewise by polynomials. ...


Address Geocoding

Geocoding is calculating spatial locations (X,Y coordinates) from street addresses. A reference theme is required to geocode individual addresses, such as a road centerline file with address ranges. The individual address locations are interpolated, or estimated, by examining address ranges along a road segment. These are usually provided in the form of a table or database. The GIS will then place a dot approximately where that address belongs along the segment of centerline. For example, an address point of 500 will be at the midpoint of a line segment that starts with address 1 and ends with address 1000. Geocoding can also be applied against actual parcel data, typically from municipal tax maps. In this case, the result of the geocoding will be an actually positioned space as opposed to an interpolated point. For other uses, see Geocoding (disambiguation). ...


It should be noted that there are several (potentially dangerous) caveats that are often overlooked when using interpolation. See the full entry for Geocoding for more information. For other uses, see Geocoding (disambiguation). ...


Various algorithms are used to help with address matching when the spellings of addresses differ. Address information that a particular entity or organization has data on, such as the post office, may not entirely match the reference theme. There could be variations in street name spelling, community name, etc. Consequently, the user generally has the ability to make matching criteria more stringent, or to relax those parameters so that more addresses will be mapped. Care must be taken to review the results so as not to erroneously map addresses incorrectly due to overzealous matching parameters.


Reverse geocoding

Reverse geocoding is the process of returning an estimated street address number as it relates to a given coordinate. For example, a user can click on a road centerline theme (thus providing a coordinate) and have information returned that reflects the estimated house number. This house number is interpolated from a range assigned to that road segment. If the user clicks at the midpoint of a segment that starts with address 1 and ends with 100, the returned value will be somewhere near 50. Note that reverse geocoding does not return actual addresses, only estimates of what should be there based on the predetermined range.


Data output and cartography

Cartography is the design and production of maps, or visual representations of spatial data. The vast majority of modern cartography is done with the help of computers, usually using a GIS. Most GIS software gives the user substantial control over the appearance of the data. Cartography or mapmaking (in Greek chartis = map and graphein = write) is the study and practice of making maps or globes. ...


Cartographic work serves two major functions:


First, it produces graphics on the screen or on paper that convey the results of analysis to the people who make decisions about resources. Wall maps and other graphics can be generated, allowing the viewer to visualize and thereby understand the results of analyses or simulations of potential events. Web Map Servers facilitate distribution of generated maps through web browsers using various implementations of web-based application programming interfaces(AJAX, Java, Flash, etc). A web map server (WMS) is a web application which provides portrayal of geographic data which is stored on the server. ... // Ajax may refer to: Ajax the Great as a well known hero from the Trojan war and son of Telamon Ajax the Lesser son of the king of Locris, and another hero in the Trojan war Ajax (missionary), Arian missionary who converted the pagan Suevi c. ... Java is an object-oriented programming language developed primarily by James Gosling and colleagues at Sun Microsystems. ... Adobe Flash - previously called Shockwave Flash and Macromedia Flash - is a set of multimedia technologies developed and distributed by Adobe Systems and earlier by Macromedia. ...


Second, other database information can be generated for further analysis or use. An example would be a list of all addresses within one mile (1.6 km) of a toxic spill.


Graphic display techniques

Traditional maps are abstractions of the real world, a sampling of important elements portrayed on a sheet of paper with symbols to represent physical objects. People who use maps must interpret these symbols. Topographic maps show the shape of land surface with contour lines; the actual shape of the land can be seen only in the mind's eye. // Topographic maps are a variety of maps characterized by large-scale detail and quantitative representation of relief, usually using contour lines in modern mapping, but historically using a variety of methods. ... Contour and Contour map redirect here. ...


Today, graphic display techniques such as shading based on altitude in a GIS can make relationships among map elements visible, heightening one's ability to extract and analyze information. For example, two types of data were combined in a GIS to produce a perspective view of a portion of San Mateo County, California. For other uses, see Shade (disambiguation). ... Altitude is the elevation of an object from a known level or datum. ... San Mateo County is a county located in the San Francisco Bay Area. ... This article is about the U.S. state. ...

  • The digital elevation model, consisting of surface elevations recorded on a 30-meter horizontal grid, shows high elevations as white and low elevation as black.
  • The accompanying Landsat Thematic Mapper image shows a false-color infrared image looking down at the same area in 30-meter pixels, or picture elements, for the same coordinate points, pixel by pixel, as the elevation information.

A GIS was used to register and combine the two images to render the three-dimensional perspective view looking down the San Andreas Fault, using the Thematic Mapper image pixels, but shaded using the elevation of the landforms. The GIS display depends on the viewing point of the observer and time of day of the display, to properly render the shadows created by the sun's rays at that latitude, longitude, and time of day. 3D rendering of a DEM of Tithonium Chasma on Mars A digital elevation model (DEM) is a digital representation of ground surface topography or terrain. ... The Landsat program is the longest running enterprise for acqusition of imagery of Earth from space. ... Render may refer to: Rendering (computer graphics), generating the pixels of an image based on a high-level description of its components XRender, or Render, an X Window System rendering extension Industrial rendering, the processing of waste animal parts to separate the fat from the bone and protein Kitchen rendering... A cube in two-point perspective. ... View of the San Andreas Fault on the Carrizo Plain in central California, 35°07N, 119°39W The San Andreas Fault is a geological fault that runs a length of roughly 800 miles (1300 kilometres) through western and southern California in the United States. ... A landform comprises a geomorphological unit, and is largely defined by its surface form and location in the landscape, as part of the terrain, and as such, is typically an element of topography. ... For other uses, see Observation (disambiguation). ...


Spatial ETL

Spatial ETL tools provide the data processing functionality of traditional Extract, Transform, Load (ETL) software, but with a primary focus on the ability to manage spatial data. They provide GIS users with the ability to translate data between different standards and proprietary formats, whilst geometrically transforming the data en-route. Spatial ETL tools provide the data processing functionality of traditional Extract, Transform, Load (ETL) software, but with a primary focus on the ability to manage spatial data (which may also be called geographic, map or location data). ... ETL also means Express Toll Lanes, see Express Toll Lanes. ...


GIS software

Main article: List of GIS software

Geographic information can be accessed, transferred, transformed, overlaid, processed and displayed using numerous software applications. Within industry commercial offerings from companies such as ESRI and Mapinfo dominate, offering an entire suite of tools. Government and military departments often use custom software, open source products, such as GRASS, or more specialized products that meet a well defined need. Although free tools exist to view GIS datasets, public access to geographic information is dominated by online resources such as Google Earth and interactive web mapping. This is a list of notable GIS software applications. ... For the Irish research group, see Economic and Social Research Institute. ... MapInfo Corporation is a business intelligence company, headquartered in Troy, New York. ... For other uses, see Grass (disambiguation). ... Google Earth is a virtual globe program that was originally called Earth Viewer and was created by Keyhole, Inc. ...


Background

Originally up to the late 1990s, when GIS data was mostly based on large computers and used to maintain internal records, software was a stand-alone product. However with increased access to the internet and networks and demand for distributed geographic data grew, GIS software gradually changed its entire outlook to the delivery of data over a network. GIS software is now usually marketed as combination of various interoperable applications and APIs. AStand-Alone program is any program that can run without being installed. ... API redirects here. ...


Data creation

GIS processing software is used for the task of preparing data for use within a GIS. This transforms the raw or legacy geographic data into a format usable by GIS products. For example an aerial photograph may need to be stretched (orthorectified) using photogrammetry so that its pixels align with longitude and latitude gradations (or whatever grid is needed). This can be distinguished from the transformations done within GIS analysis software by the fact that these changes are permanent, more complex and time consuming. Thus, a specialized high-end type of software is generally used by a person skilled in Remote Sensing and / or GIS processing aspects of computer science. In addition, AutoCAD, normally used for drafts of engineering projects, can be configured for the editing of vector maps, and has some products that have migrated towards GIS use. It is especially useful as it has strong support for digitization. Raw geographic data can be edited in many standard database and spreadsheet applications and in some cases a text editor may be used as long as care is taken to properly format data. Photogrammetry is a remote sensing technology in which geometric properties about objects are determined from photographic images. ... For the purported psychic ability to sense remotely, see Remote viewing right Synthetic aperture radar image of Death Valley colored using polarimetry In the broadest sense, remote sensing is the short or large-scale acquisition of information of an object or phenomenon, by the use of either recording or real... AutoCAD is a CAD software application for 2D and 3D design and drafting, developed and sold by Autodesk, Inc. ... An engineering drawing is a type of drawing that is technical in nature, used to fully and clearly define requirements for engineered items, and is usually created in accordance with standardized conventions for layout, nomenclature, interpretation, appearance (such as typefaces and line styles), size, etc. ... Digitizing, or digitization, is the process of turning an analog signal into a digital representation of that signal. ...


Geodatabases

Main article: Geodatabase

A geodatabase is a database with extensions for storing, indexing, querying, and manipulating geographic information and spatial data. While some geodatabases have functions built in to allow geoprocessing the primary benefit of a geodatabase is in the "database type" capabilities that it gives to spatial data. Some of these capabilities include easy access using standard database drivers such as ODBC, the ability to easily link or join data tables, also indexing and grouping of spatial datasets independent of software platform. A geodatabase is a database designed to store, query, and manipulate geographic information and spatial data. ... This article is about computing. ...


Management and analysis

GIS analysis software takes GIS data and overlays or otherwise combines it so that the data can be visually analysed. It can output a detailed map, image or movie used to communicate an idea or concept with respect to a region of interest. This is usually used by persons who are trained in cartography, geography or a GIS professional as this type of application is complex and takes some time to master. The software performs transformation on raster and vector data sometimes of differing datums, grid system, or reference system, into one coherent image. It can also analyse changes over time within a region. This software is central to the professional analysis and presentation of GIS data. Examples include the ArcGIS family of ESRI GIS applications (which replaced ESRI's older Arc/INFO), Smallworld, Civil Designer, XMap and GRASS. ArcGIS is the name of a group of Geographic Information System software product lines produced by ESRI. At the desktop GIS level, ArcGIS can include: ArcReader, which allows one to view and query maps created with the other Arc products; ArcView, which allows one to view spatial data, create maps... ArcInfo is a Geographic Information System program produced by ESRI. The name ArcInfo is used to refer to a level of licensing for ArcGIS. ArcInfo is the higest level of licensing in the ArcGIS product line and is the most complete GIS solution avaliable from ESRI. It includes and builds... Smallworld was a GIS company founded in Cambridge, England, in 1989 by Dick Newell and others. ... For other uses, see Grass (disambiguation). ...


Statistical

GIS statistical software uses standard database queries to retrieve and analyse data for decision making. For example, if one has geographic data that includes detailed demographic information, one can determine how many individuals of a certain age, income, and ethnicity live in a given street block. The data is sometimes referenced with postal codes or street locations rather than with geodetic data. This can be used by computer scientists and statisticians with computer science skills, with an objective of characterizing an area to aid in decisions regarding marketing, social services, emergency planning, etc. Standard DBMS can be used or specialized GIS statistical software. These are often housed on servers so that they can be queried with web browsers. Examples are MySQL or ArcSDE. Computer science, or computing science, is the study of the theoretical foundations of information and computation and their implementation and application in computer systems. ... Next big thing redirects here. ... A database management system (DBMS) is computer software designed for the purpose of managing databases based on a variety of data models. ... An example of a Web browser (Mozilla Firefox) A web browser is a software application that enables a user to display and interact with text, images, videos, music and other information typically located on a Web page at a website on the World Wide Web or a local area network. ... MySQL (pronounced (IPA) , my S-Q-L[1]) is a multithreaded, multi-user SQL database management system (DBMS)[2] which has, according to MySQL AB, more than 10 million installations. ... ArcSDE is a middleware software package made by ESRI to manage RDBMSs for the purpose of storing and querying spatial data. ...


Readers

GIS readers are computer applications that are designed to allow users to easily view digital maps as well as view and query GIS-managed data. By definition, they usually allow very little if any editing of the map or underlying map data. Readers can be normal standalone applications that need to be installed locally, though they are often designed to connect to data servers over the Internet to access the relevant information. Readers can also be included as an embedded application within a web page, obviating the need for local installation. Readers are designed to be relatively simple and easy to use as well as free.


Web API

This is the evolution of the scripts that were common with most early GIS systems. An application programming interface (API) is a set of subroutines (organized as object oriented programming) designed to perform a specific task. GIS APIs are designed to manage GIS data for its delivery to a web browser client from a GIS server. They are accessed with commonly used scripting language such as VBA or JavaScript. They are used to build a server system for the delivery of GIS that is to made available over an intranet or publicly over the Internet. An example of a Web browser (Mozilla Firefox) A web browser is a software application that enables a user to display and interact with text, images, videos, music and other information typically located on a Web page at a website on the World Wide Web or a local area network. ... Visual Basic for Applications (VBA) is an implementation of Microsofts Visual Basic, an event driven programming language and associated integrated development environment (IDE) which is built into most Microsoft Office applications. ... JavaScript is a scripting language most often used for client-side web development. ...


Mobile GIS

GIS has seen many implementations on mobile devices. With the widespread adoption of GPS, GIS has been used to capture and integrate data in the field.


Free and Open-source GIS software

Many GIS tasks can be accomplished with free or open-source software. Open source software is computer software for which the human-readable source code is made available under a copyright license (or arrangement such as the public domain) that meets the Open Source Definition. ...


With the broad use of non-proprietary and open data formats such as the Shape File format for vector data and the Geotiff format for raster data, as well as the adoption of OGC standards for networked servers, development of open source software continues to evolve, especially for web and web service oriented applications. Well-known open source GIS software includes GRASS GIS, Quantum GIS, MapServer, uDig, OpenJUMP, gvSIG and many others (e.g., see OSGeo or MapTools). GRASS (Geographic Resources Analysis Support System) is an open source, Free Software Geographical information system (GIS) with raster, topological vector, image processing, and graphics production functionality that operates on various platforms through a graphical user interface and shell in the X Window System. ... Quantum GIS (often abbreviated to QGIS) is an open source GIS (mapping) application which is similar to commercial mapping packages. ... MapServer is an open source internet map server, which runs as a CGI program. ... uDig is an open source GIS software program produced by a community led by Refractions Research. ... OpenJUMP is an open source GIS software written in Java. ... To meet Wikipedias quality standards and make it easier to understand, this article or section may require cleanup. ...


Much open source GIS development has focused on the creation of libraries that provide functionality for third party applications. Such libraries include GDAL/OGR, and GeoTools. These libraries are used by open source and commercial software alike to provide basic functionality. GDAL is a library for reading and writing raster geospatial data formats, and is released under an X/MIT style Open Source license by the Open Source Geospatial Foundation. ... This article is being considered for deletion in accordance with Wikipedias deletion policy. ...


PostGIS provides an open source alternative to geodatabases such as Oracle Spatial, and ArcSDE. PostGIS is a geographic information system software program that adds support for geographic objects to the PostgreSQL object-relational database. ... Oracle Spatial forms a separately-licensed option component of the Oracle Database. ... ArcSDE is a middleware software package made by ESRI to manage RDBMSs for the purpose of storing and querying spatial data. ...


Vehicle navigation

A database model of a network of roads and related features is a form of GIS data that is used for vehicle navigation systems. Such a map database is a vector representation of a given road network including road geometry (segment shape), network topology (connectivity) and related attributes (addresses, road class, etc). Geographic Data Files (GDF) is an ISO standard for formulating map databases for navigation. An Automotive navigation system will combine map-matching, GPS coordinates, and Dead reckoning to estimate the position of the vehicle. The map database is also used for route planning and guidance, and possibly advanced functions involving active safety, driver assistance and location-based services. Maintenance of databases for vehicle navigation is discussed in the article Map database management. Geographic Data Files or GDF is a file format for geographic files. ... “ISO” redirects here. ... A taxi in Kyoto, equipped with GPS navigation system An automotive navigation system is a satellite navigation system designed for use in automobiles. ... Over fifty GPS satellites such as this NAVSTAR have been launched since 1978. ... Dead reckoning (DR) is the process of estimating ones current position based upon a previously determined position, or fix, and advancing that position based upon measured velocity, time, heading, as well as the effect of currents or wind. ... Map database management stems from navigation units becoming more common in automotive vehicles (see Automotive navigation system). ...


The future of GIS

GeaBios - tiny WMS/WFS client (Flash/DHTML)
GeaBios - tiny WMS/WFS client (Flash/DHTML)

Many disciplines can benefit from GIS technology. An active GIS market has resulted in lower costs and continual improvements in the hardware and software components of GIS. These developments will, in turn, result in a much wider use of the technology throughout science, government, business, and industry, with applications including real estate, public health, crime mapping, national defense, sustainable development, natural resources, landscape architecture, archaeology, regional and community planning, transportation and logistics. GIS is also diverging into location-based services (LBS). LBS allows GPS enabled mobile devices to display their location in relation to fixed assets (nearest restaurant, gas station, fire hydrant), mobile assets (friends, children, police car) or to relay their position back to a central server for display or other processing. These services continue to develop with the increased integration of GPS functionality with increasingly powerful mobile electronics (cell phones, PDAs, laptops). Image File history File links Download high resolution version (1000x933, 647 KB) Licensing This is a screenshot of a copyrighted web page, and the copyright for it is most likely owned by owner of the website. ... Image File history File links Download high resolution version (1000x933, 647 KB) Licensing This is a screenshot of a copyrighted web page, and the copyright for it is most likely owned by owner of the website. ... www. ... An OGC Web Map Service (WMS) produces maps of spatially referenced data dynamically from geographic information. ... The OpenGIS Web Feature Service Interface Standard (WFS) is an interface allowing requests for geographical features across the web being highly interoperable. ... Adobe Flash - previously called Shockwave Flash and Macromedia Flash - is a set of multimedia technologies developed and distributed by Adobe Systems and earlier by Macromedia. ... Dynamic HTML or DHTML designates a technique of creating interactive web sites by using a combination of the static markup language HTML, a client-side scripting language (such as JavaScript) and the style definition language Cascading Style Sheets. ... In economics, a business (also called firm or enterprise) is a legally recognized organizational entity designed to provide goods and/or services to consumers or corporate entities such as governments, charities or other businesses. ... Real estate is a legal term that encompasses land along with anything permanently affixed to the land, such as buildings. ... Public health is the study and practice of addressing threats to the health of a community. ... Crime mapping is a key component of crime analysis and the CompStat policing strategy. ... Any activity or effort performed to protect a nation against attack or other threats. ... Sustainable development is a socio-ecological process characterized by the fulfilment of human needs while maintaining the quality of the natural environment indefinitely. ... Natural resources are commodities that are considered valuable in their relatively unmodified (natural) form. ... For referencing in Wikipedia, see Wikipedia:Citing sources. ... Location-based services (LBS) (or LoCation Services, LCS) are services developed and distributed by wireless carriers and their partners which provide information specific to a location. ...


Distributed GIS

Distributed GIS concerns itself with GI Systems that do not have all of the system components in the same physical location. This could be the processing, the database, the rendering or the user interface. Examples of distributed systems are web-based GIS, Mobile GIS, Corporate GIS and GRID computing. Distributed GIS concerns itself with GI Systems that do not have all of the system components in the same physical location. ...


OGC standards

OGC standards help GIS tools communicate.
OGC standards help GIS tools communicate.

The Open Geospatial Consortium (OGC) is an international industry consortium of 334 companies, government agencies and universities participating in a consensus process to develop publicly available geoprocessing specifications. Open interfaces and protocols defined by OpenGIS Specifications support interoperable solutions that "geo-enable" the Web, wireless and location-based services, and mainstream IT, and empower technology developers to make complex spatial information and services accessible and useful with all kinds of applications. Open Geospatial Consortium (OGC) protocols include Web Map Service (WMS) and Web Feature Service (WFS). The Open Geospatial Consortium, or OGC, is an international voluntary consensus standards organization. ... The Open Geospatial Consortium, or OGC, is an international voluntary consensus standards organization. ... An OGC Web Map Service (WMS) produces maps of spatially referenced data dynamically from geographic information. ... The OpenGIS Web Feature Service Interface Standard (WFS) is an interface allowing requests for geographical features across the web being highly interoperable. ...


GIS products are broken down by the OGC into two categories, based on how completely and accurately the software follows the OGC specifications.


Compliant Products are software products that comply to OGC's OpenGIS Specifications. When a product has been tested and certified as compliant through the OGC Testing Program, the product is automatically registered as "compliant" on this site.


Implementing Products are software products that implement OpenGIS Specifications but have not yet passed a compliance test. Compliance tests are not available for all specifications. Developers can register their products as implementing draft or approved specifications, though OGC reserves the right to review and verify each entry.


Web mapping

Main article: Web mapping

In recent years there has been an explosion of mapping applications on the web such as Google Maps and Live Maps. These websites give the public access to huge amounts of geographic data. Web mapping is the process of designing, implementing, generating and delivering maps on the World Wide Web. ... Google Maps (for a time named Google Local) is a free web mapping service application and technology provided by Google that powers many map-based services including the Google Maps website, Google Ride Finder and embedded maps on third-party websites via the Google Maps API. It offers street maps... MSN Virtual Earth in Internet Explorer 6 Live Search Maps (previously Windows Live Maps and Windows Live Local), is a web mapping service provided as a part of Microsofts Windows Live online applications services suite and powered by Microsofts Virtual Earth. // Detailed street maps are available for many...


Some of them, like Google Maps and OpenLayers, expose an API that enable users to create custom applications. These toolkits commonly offer street maps, aerial/satellite imagery, geocoding, searches, and routing functionality. API redirects here. ...


Other applications for publishing geographic information on the web include MapInfo's MapXtreme, Intergraph's GeoMedia WebMap (TM), ESRI's ArcIMS, ArcGIS Server, AutoDesk's Mapguide, SeaTrails' AtlasAlive, and the open source MapServer. Intergraph was founded in 1969 as M&S Computing, Inc. ... ArcIMS (standing for ArcInternet Map Server) is an online mapping product produced by ESRI. It is a GIS that is designed to server maps across the Internet. ... MapServer is an open source internet map server, which runs as a CGI program. ...


In recent years web mapping services have begun to adopt features more common in GIS. Services such as Google Maps and Live Maps allow users to annotate maps and share the maps with others. Conversely, GIS vendors have also created web mapping systems such as ESRI's WebADF that adopt much of the usability and speed of consumer web mapping web sites. Google Maps (for a time named Google Local) is a free web mapping service application and technology provided by Google that powers many map-based services including the Google Maps website, Google Ride Finder and embedded maps on third-party websites via the Google Maps API. It offers street maps... MSN Virtual Earth in Internet Explorer 6 Live Search Maps (previously Windows Live Maps and Windows Live Local), is a web mapping service provided as a part of Microsofts Windows Live online applications services suite and powered by Microsofts Virtual Earth. // Detailed street maps are available for many... For the Irish research group, see Economic and Social Research Institute. ...


Global change and climate history program

Maps have traditionally been used to explore the Earth and to exploit its resources. GIS technology, as an expansion of cartographic science, has enhanced the efficiency and analytic power of traditional mapping. Now, as the scientific community recognizes the environmental consequences of human activity, GIS technology is becoming an essential tool in the effort to understand the process of global change. Various map and satellite information sources can combine in modes that simulate the interactions of complex natural systems.


Through a function known as visualization, a GIS can be used to produce images - not just maps, but drawings, animations, and other cartographic products. These images allow researchers to view their subjects in ways that literally never have been seen before. The images are often invaluable for conveying the technical concepts of GIS study subjects to non-scientists.


Adding the dimension of time

The condition of the Earth's surface, atmosphere, and subsurface can be examined by feeding satellite data into a GIS. GIS technology gives researchers the ability to examine the variations in Earth processes over days, months, and years.


As an example, the changes in vegetation vigor through a growing season can be animated to determine when drought was most extensive in a particular region. The resulting graphic, known as a normalized vegetation index, represents a rough measure of plant health. Working with two variables over time would then allow researchers to detect regional differences in the lag between a decline in rainfall and its effect on vegetation.


GIS technology and the availability of digital data on regional and global scales enable such analyses. The satellite sensor output used to generate a vegetation graphic is produced by the Advanced Very High Resolution Radiometer (AVHRR). This sensor system detects the amounts of energy reflected from the Earth's surface across various bands of the spectrum for surface areas of about 1 square kilometer. The satellite sensor produces images of a particular location on the Earth twice a day. AVHRR is only one of many sensor systems used for Earth surface analysis. More sensors will follow, generating ever greater amounts of data. The Advanced Very High Resolution Radiometer (AVHRR) is a space-borne sensor embarked on the National Oceanic and Atmospheric Administration (NOAA) family of polar orbiting platforms. ...


GIS and related technology will help greatly in the management and analysis of these large volumes of data, allowing for better understanding of terrestrial processes and better management of human activities to maintain world economic vitality and environmental quality.


In addition to the integration of time in environmental studies, GIS is also being explored for its ability to track and model the progress of humans throughout their daily routines. A concrete example of progress in this area is the recent release of time-specific population data by the US Census. In this data set, the populations of cities are shown for daytime and evening hours highlighting the pattern of concentration and dispersion generated by North American commuting patterns. The manipulation and generation of data required to produce this data would not have been possible without GIS. The United States Census Bureau (officially Bureau of the Census) is a part of the United States Department of Commerce. ...


Using models to project the data held by a GIS forward in time have enabled planners to test policy decisions. These systems are known as Spatial Decision Support Systems. Spatial Decision Support Systems (sDSS) developed in parallel with the concept of Decision Support Systems (DSS). ...


Semantics and GIS

Tools and technologies emerging from the W3C's Semantic Web Activity are proving useful for data integration problems in information systems. Correspondingly, such technologies have been proposed as a means to facilitate interoperability and data reuse among GIS applications [9][10] and also to enable new analysis mechanisms [11]. WWWC redirects here. ... W3Cs Semantic Web logo The Semantic Web is an evolving extension of the World Wide Web in which web content can be expressed not only in natural language, but also in a format that can be read and used by software agents, thus permitting them to find, share and... Data integration is the process of combining data residing at different sources and providing the user with a unified view of these data [1]. This process emerges in a variety of situations both commercial (when two similar companies need to merge their databases) and scientific (combining research results from different... Interoperability is a property referring to the ability of diverse systems and organizations to work together (inter-operate). ...


Ontologies are a key component of this semantic approach as they allow a formal, machine-readable specification of the concepts and relationships in a given domain. This in turn allows a GIS to focus on the meaning of data rather than its syntax or structure. For example, reasoning that a land cover type classified as Deciduous Needleleaf Trees in one dataset is a specialization of land cover type Forest in another more roughly-classified dataset can help a GIS automatically merge the two datasets under the more general land cover classification. Very deep and comprehensive ontologies have been developed in areas related to GIS applications, for example the Hydrology Ontology developed by the Ordnance Survey in the United Kingdom and the SWEET ontologies developed by NASA's Jet Propulsion Laboratory. Also, simpler ontologies and semantic metadata standards are being proposed by the W3C Geo Incubator Group to represent geospatial data on the web. In both computer science and information science, an ontology is a data model that represents a set of concepts within a domain and the relationships between those concepts. ... Reasoning is the mental (cognitive) process of looking for reasons to support beliefs, conclusions, actions or feelings. ... Specialization, also spelled Specialisation, is an important way to generate propositional knowledge, by applying general knowledge, such as the theory of gravity, to specific instances, such as when I release this apple, it will fall to the floor. Specialization is the opposite of generalization. ... Part of an Ordnance Survey map at 1 inch to the mile scale from 1945 Ordnance Survey (OS) is an executive agency of the United Kingdom government. ... For other uses, see NASA (disambiguation). ... For the singer/songwriter, see Jon Peter Lewis. ...


Recent research results in this area can be seen in the International Conference on Geospatial Semantics and the Terra Cognita -- Directions to the Geospatial Semantic Web workshop at the International Semantic Web Conference.


GIS and Society

Main article: Neogeography

With the popularization of GIS in decision making, scholars have began to scrutinize the social implications of GIS. It has been argued that the production, distribution, utilization, and representation of geographic information are largely related with the social context. For example, some scholars are concerned that GIS may turn into a tool of omni-surveillance for dictatorship. Other related topics include discussion on copyright, privacy, and censorship. A more optimistic social approach to GIS adoption is to use it as a tool for public participation. Neogeography means new geography and consists of a set of techniques and tools that fall outside the realm of traditional GIS, Geographic Information Systems. ... Public Participation Geographic Information Systems (PPGIS) was born, as a term, in 1996 at the meetings of the National Center for Geographic Information and Analysis (NCGIA) (Sieber 2006). ...


See also

Atlas Portal

Image File history File links Download high resolution version (1357x628, 23 KB) File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... AM/FM/GIS stands for Automated Mapping/Facilities Management and is a subset of GIS, which is associated with public utilities like gas, electric, water and telecommunications. ... Cartography or mapmaking (in Greek chartis = map and graphein = write) is the study and practice of making maps or globes. ... Crime mapping is a key component of crime analysis and the CompStat policing strategy. ... Categories: Stub | Cartography ... Distributed GIS concerns itself with GI Systems that do not have all of the system components in the same physical location. ... An old geodetic pillar (1855) at Ostend, Belgium A Munich archive with lithography plates of maps of Bavaria Geodesy (pronounced [1]), also called geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravity field, in a three... Geoinformatics is a science which develops and uses information science infrastructure to address the problems of geosciences and related branches of engineering. ... ‘Truth, as in a single, incontrovertible and correct fact, simply does not exist for much geographical information’ (Comber et al. ... Geoinformation is a shorter name of Geographic Information. ... Survey equipment used in geomatics Geomatics is the discipline of gathering, storing, processing, and delivering of geographic information, or spatially referenced information. ... In marketing, geo (also called marketing geography) is a discipline within marketing analysis which uses geolocation (geographic information) in the process of planning and implementation of marketing activities. ... This is a list of notable GIS software applications. ... This is a comparison of notable GIS software. ... The Open Source Geospatial Foundation (OSGeo), is a non-profit non-governmental organization whose mission is to support and promote the collaborative development of open geospatial technologies and data. ... The Open Geospatial Consortium or OGC groups more than 250 commercial, governmental, nonprofit and research organisations worldwide, encouraging and prescribing standards for GIS data processing and exchange. ... Public Participation Geographic Information Systems (PPGIS) was born, as a term, in 1996 at the meetings of the National Center for Geographic Information and Analysis (NCGIA) (Sieber 2006). ... Pictometry International is a Rochester, New York-based company that provides detailed aerial photography. ... For the purported psychic ability to sense remotely, see Remote viewing right Synthetic aperture radar image of Death Valley colored using polarimetry In the broadest sense, remote sensing is the short or large-scale acquisition of information of an object or phenomenon, by the use of either recording or real... Traditional knowledge Geographic Information Systems (GIS) are the data, techniques, and technologies designed to document and utilize local knowledges in communities around the world. ... NASA World Wind, an open source virtual globe with stars and advanced atmosphere & sunlight effects Microsoft Virtual Earth 3D within Windows Live Local site Earthsim, real-time Earth render with atmosphere modeling 3D Weather Globe & Atlas, Earth render with satellite cloud coverage and atmosphere A virtual globe is a 3D... Topologically Integrated Geographic Encoding and Referencing, or TIGER, or TIGER/Line is a format used by the United States Census Bureau to describe land attributes such as roads, buildings, rivers, and lakes. ... At-location mapping (ALM) is closely related to location-based services (LBS). ... GIS or Geographic Information Systems has over the last 10 years become an important tool in archaeology. ... A Historical GIS is a Geographical Information System that may display, store and analyze data of past geographies and track changes in time. ... A taxi in Kyoto, equipped with GPS navigation system An automotive navigation system is a satellite navigation system designed for use in automobiles. ... Map database management stems from navigation units becoming more common in automotive vehicles (see Automotive navigation system). ... Geographic Data Files or GDF is a file format for geographic files. ... Mr. ...

References

  1. ^ Lascaux Cave. French Ministry of Culture. Retrieved on 2008-02-13.
  2. ^ Curtis, Gregory. The Cave Painters: Probing the Mysteries of the World's First Artists. NY, USA: Knopf. ISBN 1-4000-4348-4. 
  3. ^ Dr David Whitehouse. Ice Age star map discovered. BBC. Retrieved on 2007-06-09.
  4. ^ John Snow's Cholera Map. York University. Retrieved on 2007-06-09.
  5. ^ Joseph H. Fitzgerald. Map Printing Methods. Retrieved on 2007-06-09.
  6. ^ GIS Hall of Fame - Roger Tomlinson. URISA. Retrieved on 2007-06-09.
  7. ^ Lucia Lovison-Golob. Howard T. Fisher. Harvard University. Retrieved on 2007-06-09.
  8. ^ Gao, Shan. Paynter, John. & David Sundaram, (2004) "Flexible Support for Spatial Decision-Making" Proc. of the 37th Hawaii International Conference on System Sciences 5-8 pp. 10]
  9. ^ Fonseca, Frederico & Sheth, Amit (2002), "The Geospatial Semantic Web", UCGIS White Paper 
  10. ^ Fonseca, Frederico & Egenhofer, Max (1999), "Ontology-Driven Geographic Information Systems", Proc. ACM International Symposium on Geographic Information Systems, pp. 14-19 
  11. ^ Perry, Matthew; Hakimpour, Farshad & Sheth, Amit (2006), "Analyzing Theme, Space and Time: an Ontology-based Approach", Proc. ACM International Symposium on Geographic Information Systems, pp. 147-154 

2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... is the 44th day of the year in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 160th day of the year (161st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 160th day of the year (161st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 160th day of the year (161st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 160th day of the year (161st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 160th day of the year (161st in leap years) in the Gregorian calendar. ...

Further reading

  • Berry, J.K. (1993) Beyond Mapping: Concepts, Algorithms and Issues in GIS. Fort Collins, CO: GIS World Books.
  • Bolstad, P. (2005) GIS Fundamentals: A first text on Geographic Information Systems, Second Edition. White Bear Lake, MN: Eider Press, 543 pp.
  • Burrough, P.A. and McDonnell, R.A. (1998) Principles of geographical information systems. Oxford University Press, Oxford, 327 pp.
  • Chang, K. (2007) Introduction to Geographic Information System, 4th Edition. McGraw Hill.
  • Coulman, Ross (2001 - present) Numerous GIS White Papers
  • Elangovan,K (2006)"GIS: Fundamentals, Applications and Implementations", New India Publishing Agency, New Delhi"208 pp.
  • Heywood, I., Cornelius, S., and Carver, S. (2006) An Introduction to Geographical Information Systems. Prentice Hall. 3rd edition.
  • Longley, P.A., Goodchild, M.F., Maguire, D.J. and Rhind, D.W. (2005) Geographic Information Systems and Science. Chichester: Wiley. 2nd edition.
  • Maguire, D.J., Goodchild M.F., Rhind D.W. (1997) "Geographic Information Systems: principles, and applications" Longman Scientific and Technical, Harlow.
  • Ott, T. and Swiaczny, F. (2001) Time-integrative GIS. Management and analysis of spatio-temporal data, Berlin / Heidelberg / New York: Springer.
  • Thurston, J., Poiker, T.K. and J. Patrick Moore. (2003) Integrated Geospatial Technologies: A Guide to GPS, GIS, and Data Logging. Hoboken, New Jersey: Wiley.
  • Tomlinson, R.F., (2005) Thinking About GIS: Geographic Information System Planning for Managers. ESRI Press. 328 pp.
  • Wise, S. (2002) GIS Basics. London: Taylor & Francis.
  • Worboys, Michael, and Matt Duckham. (2004) GIS: a computing perspective. Boca Raton: CRC Press.
  • Wheatley, David and Gillings, Mark (2002) Spatial Technology and Archaeology. The Archaeological Application of GIS. London, New York, Taylor & Francis.

Michael Frank Goodchild (born February 24, 1944) is a British-American geographer. ... Professor David William Rhind CBE was Vice Chancellor of City University until July 2007 and Chairman of the Nuclear Decommissioning Authorities Socio-economic Committee. ...

External links

For the books called Geography by Ancient Greek authors, see Geographia (Ptolemy) and Geographica (Strabo) For the magazine of the Royal Geographical Society, see Geographical (magazine) Geography is the study of the earth and its features, inhabitants, and phenomena. ... This article explores the history of geography. ... Geography is the study of the Earth and its features and of the distribution of life on the earth, including human life and the effects of human activity. ... List of Geographers The geographers are listed below in English alphabetical transliteration order (by surnames). ... This is a list of geography topics: Geography of countries Geography of Afghanistan Geography of Albania Geography of Algeria Geography of American Samoa Geography of Andorra Geography of Angola Geography of Anguilla Geography of Antarctica Geography of Antigua and Barbuda Geography of Argentina Geography of Armenia Geography of Aruba Geography... Population density by country, 2007 Human geography, is a branch of geography that focuses on the study of patterns and processes that shape human interaction with the environment, with particular reference to the causes and consequences of the spatial distribution of human activity on the Earths surface. ... Behavioral geography is an approach to Human Geography that examines human behavior using a disaggregate approach. ... Cultural geography is a sub-field within human geography. ... Map of countries by population Population growth showing projections for later this century Demography is the statistical study of all populations. ... Development geography is the study of the Earths geography and its relationship with economic development. ... Economic geography is the study of the location, distribution and spatial organisation of economic activities across the Earth. ... Feminist geography is an approach to study in human geography which applies the theories, methods and critiques of feminism to the study of the human environment, society and geographical space. ... Historical Geography is the study of the: Human Physical Fictional Theoretical and Real geographies of the past. ... Political geography is the field of human geography that is concerned with the study of both the spatially uneven outcomes of political processes and the ways in which political processes are themselves affected by spatial structures. ... Regional geography is a study of regions throughout the world in order to understand or define the unique characteristics of a particular region which consists of natural as well as human elements. ... Urban geography is the study of urban areas. ... True-color image of the Earths surface and atmosphere Physical geography (also know as geosystems or physiography) is a subfield of geography that focuses on the systematic study of patterns and processes within the hydrosphere, biosphere, atmosphere, and lithosphere. ... Biogeography is the science which deals with patterns of species distribution and the processes that result in such patterns. ... Climatology is the study of climate, scientifically defined as weather conditions averaged over a period of time,[1] and is a branch of the atmospheric sciences. ... Coastal geography is the study of the dynamic interface between the ocean and the land, incorporating both the physical geography(i. ... Environmental geography is the branch of geography that describes the spatial aspects of interactions between humans and the natural world. ... An old geodetic pillar (1855) at Ostend, Belgium A Munich archive with lithography plates of maps of Bavaria Geodesy (pronounced [1]), also called geodetics, a branch of earth sciences, is the scientific discipline that deals with the measurement and representation of the Earth, including its gravity field, in a three... Surface of the Earth Geomorphology is the study of landforms, including their origin and evolution, and the processes that shape them. ... Lateral moraine on a glacier joining the Gorner Glacier, Zermatt, Switzerland. ... Water covers 70% of the Earths surface. ... Landscape ecology is a sub-discipline of ecology and geography that address how spatial variation in the landscape affects ecological processes such as the distribution and flow of energy, materials and individuals in the environment (which, in turn, may influence the distribution of landscape elements themselves such as hedgerows). ... Lake Geneva Limnology (from Greek: Λίμνη limne, lake; and λόγος, logos, knowledge) is the study of inland waters (both fresh and saline), including their biological, physical, chemical, geological and hydrological aspects. ... Thermohaline circulation Oceanographic frontal systems on the southern hemisphere Oceanography (from the greek words Ωκεανός meaning Ocean and γράφω meaning to write), also called oceanology or marine science, is the branch of Earth Sciences that studies the Earths oceans and seas. ... Paleogeography (sometimes spelled palaeogeography) is the study of the ancient geologic environments of the Earths surface as preserved in the stratigraphic record. ... Pedology (pÄ›dÇ’lōgy), (from Russian: pedologiya, from the Greek pedon = soil, earth), is the study of soils and soil formation. ... Quaternary science is an inter-disciplinary field of study focusing on the Quaternary period, which encompasses the last 2. ... Cartography or mapmaking (in Greek chartis = map and graphein = write) is the study and practice of making maps or globes. ... This article or section is in need of attention from an expert on the subject. ... GPS redirects here. ... For the purported psychic ability to sense remotely, see Remote viewing right Synthetic aperture radar image of Death Valley colored using polarimetry In the broadest sense, remote sensing is the short or large-scale acquisition of information of an object or phenomenon, by the use of either recording or real... Spatial data analysis is a quantitative approach to geographical analysis that applies rigorous statistical techniques to geographic data, to ultimately analyze why phenomena occurs in particular places, and what dynamic factors are key. ... Qualitative research is one of the two major approaches to research methodology in social sciences. ... The American Geographical Society (AGS) was founded in 1851 in New York City, New York as a non-profit organization with the goal of increasing worldwide knowledge of geography. ... Logo of the AAG The Association of American Geographers (AAG) is an educational and scientific society aimed at advancing the understanding of, study of, and importance of geography and related fields. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The Geographical Association is a Sheffield,United Kingdom-based organisation that aims to further the teaching of geography and to communicate the value of learning geography for all. ... The Hong Kong Geographical Association exists to promote interest in, stimulate teaching of, and research in Geography. ... The International Geographical Union (Union Géographique Internationale; IGU / UGI) was founded in Brussels, Belgium, in 1922. ... This article is about the organization. ... The Royal Canadian Geographical Society is dedicated to imparting a broader knowledge and deeper appreciation of Canada — its people and places, its natural and cultural heritage and its environmental, social and economic challenges. ... The Royal Geographical Society is a British learned society founded in 1830 with the name Geographical Society of London for the advancement of geographical science, under the patronage of King William IV. It absorbed the Association for Promoting the Discovery of the Interior Parts of Africa (founded by Sir Joseph... The Royal Scottish Geographical Society is a learned society in Scotland, founded in 1884. ... The Russian Geographical Society is a learned society, founded on 6 August 1845 in Saint Petersburg, Russia. ... The Saudi Geographical Society (Arabic: , Aj-jamaiya Aj-joÄ¡rafïya as-Saʻūdiyya), a learned society headquartered in King Saud University, Riyadh in the Kingdom of Saudi Arabia, is a non-for-profit organization for workers and experts in geography. ... The Society of Woman Geographers was established in 1925 by ten women including Harriet Chalmers Adams, Marguerite Harrison, Blair Niles, Gertrude Shelby, and Gertrude Emerson Sen. ... The Société de Géographie, Paris, is the worlds oldest geographical society. ...

  Results from FactBites:
 
Online Encyclopedia and Dictionary - Geographic information system (3704 words)
Geographic information systems technology can be used for scientific investigations, resource management, asset management, development planning, cartography and route planning.
CGIS was the world's first "system" and was an improvement over "mapping" applications as it provided capabilities for overlay, measurement, digitizing/scanning, supported a national coordinate system that spanned the continent, coded lines as "arcs" having a true embedded topology, and it stored the attribute and locational information in separate files.
These systems allow data to be captured in 2 and 3 dimensions, with elevations measured directly from a stereo pair using principles of photogrammetry.
  More results at FactBites »

 
 

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