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Distributed GIS refers to GI Systems that do not have all of the system components in the same physical location. [1] This could be the processing, the database, the rendering or the user interface. It represents a special case of distributed computing, with examples of distributed systems including Internet GIS, Web GIS, and Mobile GIS. Distribution of resources provides corporate and enterprise-based models for GIS (involving multiple databases, different computers undertaking spatial analysis and a diverse ecosystem of often spatially-enabled client devices). Distributed GIS permits a shared services model, including data fusion (or mashups) based on Open Geospatial Consortium (OGC) web services. Distributed GIS technology enables modern online mapping systems (such as Google Maps and Bing Maps), Location-based services (LBS), web-based GIS (such as ArcGIS Online) and numerous map-enabled applications. Other applications include transportation, logistics, utilities, farm / agricultural information systems, real-time environmental information systems and the analysis of the movement of people. In terms of data, the concept has been extended to include volunteered geographical information. Distributed processing allows improvements to the performance of spatial analysis through the use of techniques such as parallel processing.
The term Distributed GIS was coined by Bruce Gittings at the University of Edinburgh. He was responsible for one of the first Internet-based distributed GIS. In 1994, he designed and implemented the World Wide Earthquake Locator, which provided maps of recent earthquake occurrences to a location-independent user, which used the Xerox PARC Map Viewer (based in California, USA), managed by an interface based in Edinburgh (Scotland), which drew data in real-time from the National Earthquake Information Center (USGS) in Colorado, USA. [2] Gittings first taught a course in Distributed GIS in 2005 as part of the Masters Programme in GIS at that institution . [3]
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Parallel processing is the use of multiple CPU’s to execute different sections of a program together. The terms "concurrent computing," "parallel computing," and "distributed computing" do not have a clear distinction between them. [4] Parallel computing today involves the utilization of a single computer with multi-core processors or multiple computers that are connected over a network working on the same task. [5] [6] In the case of Distributed GIS, parallel computing using multi-core processors on the same machine would be where the line starts to blur between traditional desktop GIS and distributed. When done in different locations, it is much clearer. As parallel computing has become the dominant paradigm in computer architecture, mainly in the form of multi-core processors, this is important to mention. [5]
Today, there are many examples of applying parallel computing to GIS. For example, remote sensing and surveying equipment have been providing vast amounts of spatial information, and how to manage, process or dispose of this data have become major issues in the field of Geographic Information Science (GIS). [7] To solve these problems there has been much research into the area of parallel processing of GIS information. This involves the utilization of a single computer with multiple processors or multiple computers that are connected over a network working on the same task, or series of tasks. The hadoop framework has been used successfully in GIS processing. [8]
Enterprise GIS refers to a geographical information system that integrates geographic data across multiple departments and serves the whole organisation. [9] The basic idea of an enterprise GIS is to deal with departmental needs collectively instead of individually. When organisations started using GIS in the 1960s and 1970s, the focus was on individual projects where individual users created and maintained data sets on their own desktop computers. Due to extensive interaction and work-flow between departments, many organisations have in recent years switched from independent, stand-alone GIS systems to more integrated approaches that share resources and applications. [10]
Some of the potential benefits that an enterprise GIS can provide include significantly reduced redundancy of data across the system, improved accuracy and integrity of geographic information, and more efficient use and sharing of data. [11] Since data is one of the most significant investments in any GIS program, any approach that reduces acquisition costs while maintaining data quality is important. The implementation of an enterprise GIS may also reduce the overall GIS maintenance and support costs providing a more effective use of departmental GIS resources. Data can be integrated and used in decision making processes across the whole organisation. [11]
A corporate Geographical Information System, is similar to Enterprise GIS and satisfies the spatial information needs of an organisation as a whole in an integrated manner. [12] Corporate GIS consists of four technological elements which are data, standards, information technology and personnel with expertise. It is a coordinated approach that moves away from fragmented desktop GIS. The design of a corporate GIS includes the construction of a centralised corporate database that is designed to be the principle resource for an entire organisation. The corporate database is specifically designed to efficiently and effectively suit the requirements of the organisation. Essential to a corporate GIS is the effective management of the corporate database and the establishment of standards such as OGC for mapping and database technologies.
Benefits include that all the users in the organisation have access to shared, complete, accurate, high quality and up-to-date data. All the users in the organisation also have access to shared technology and people with expertise. This improves the efficiency and effectiveness of the organisation as a whole. A successfully managed corporate database reduces redundant collection and storage of information across the organisation. By centralising resources and efforts, it reduces the overall cost.
Internet GIS, or Internet geographic information system (GIS), is a term that refers to a broad set of technologies and applications that employ the Internet to access, analyze, visualize, and distribute spatial data. [13] [14] [15] [16] [17] Internet GIS is an outgrowth of traditional GIS, and represents a shift from conducting GIS on an individual computer to working with remotely distributed data and functions. [13] Two major issues in GIS are accessing and distributing spatial data and GIS outputs. [18] Internet GIS helps to solve that problem by allowing users to access vast databases impossible to store on a single desktop computer, and by allowing rapid dissemination of both maps and raw data to others. [19] [18] These methods include both file sharing and email. This has enabled the general public to participate in map creation and make use of GIS technology. [20] [21]
Cell phones and other wireless communication forms have become common in society. [1] [33] [34] [35] Many of these devices are connected to the internet and can access internet GIS applications like any other computer. [33] [34] These devices are networked together, using technology such as the mobile web. Unlike traditional computers, however, these devices generate immense amounts of spatial data available to the device user and many governments and private entities. [33] [34] The tools, applications, and hardware used to facilitate GIS through the use of wireless technology is mobile GIS. Used by the holder of the device, mobile GIS enables navigation applications like Google Maps to help the user navigate to a location. [33] [34] When used by private firms, the location data collected can help businesses understand foot traffic in an area to optimize business practices. [33] [34] Governments can use this data to monitor citizens. Access to locational data by third parties has led to privacy concerns. [33] [34]
With ~80% of all data deemed to have a spatial component, modern Mobile GIS is a powerful tool. [36] The number of mobile devices in circulation has surpassed the world's population (2013) with a rapid acceleration in iOS, Android and Windows 8 tablet up-take. Tablets are fast becoming popular for Utility field use. Low-cost MIL-STD-810 certified cases transform consumer tablets into fully ruggedized yet lightweight field-use units at 10% of legacy ruggedized laptop costs.
Although not all applications of mobile GIS are limited by the device, many are. These limitations are more applicable to smaller devices such as cell phones and PDAs. Such devices have small screens with poor resolution, limited memory and processing power, a poor (or no) keyboard, and short battery life. Additional limitations can be found in web client-based tablet applications: poor web GUI and device integration, online reliance, and very limited offline web client cache.
Mobile GIS has a significant overlap with internet GIS; however, not all mobile GIS employs the internet, much less the mobile web. [1] Thus, the categories are distinct. [1]
CyberGIS, or cyber geographic information science and systems, is a term used to describe the use of cyberinfrastructure, to perform GIS tasks with storage and processing resources of multiple institutions through, usually through the World Wide Web. [37] CyberGIS focuses on computational and data-intensive geospatial problem-solving within various research and education domains by leveraging the power of distributed computation. CyberGIS has been described as "GIS detached from the desktop and deployed on the web, with the associated issues of hardware, software, data storage, digital networks, people, training and education." [38] The term CyberGIS first entered the literature in 2010, and is predominantly used by the University of Illinois at Urbana-Champaign and collaborators to describe their software and research developed to use big data and high-performance computing approaches to collaborative problem-solving. [37] [39]
In 2014, the CyberGIS Center for Advanced Digital and Spatial Studies at the University of Illinois at Urbana-Champaign received a National Science Foundation major research instrumentation grant to establish ROGER as the first cyberGIS supercomputer. ROGER, hosted by the National Center for Supercomputing Applications, is optimized to deal with geospatial data and computation and is equipped with:
CyberGIS software and tools integrate these system components to support a large number of users who are investigating scientific problems in areas spanning biosciences, engineering, geosciences, and social sciences.
Location-based services (LBS) are services that are distributed wirelessly and provide information relevant to the user's current location. These services include such things as ‘find my nearest …’, directions, and various vehicle monitoring systems, such as the GM OnStar system amongst others. Location-based services are generally run on mobile phones and PDAs, and are intended for use by the general public more than Mobile GIS systems which are geared towards commercial enterprise. Devices can be located by triangulation using the mobile phone network and/or GPS.
A web mapping service is a means of displaying and interacting with maps on the Web. The first web mapping service was the Xerox PARC Map Viewer built in 1993 and decommissioned in 2000.
There have been 3 generations of web map service. The first generation was from 1993 onwards and consisted of simple image maps which had a single click function. The second generation was from 1996 onwards and still used image maps the one click function. However, they also had zoom and pan capabilities (although slow) and could be customised through the use of the URL API. The third generation was from 1998 onwards and were the first to include slippy maps. They utilise AJAX technology which enables seamless panning and zooming. They are customisable using the URL API and can have extended functionality programmed in using the DOM.
Web map services are based on the concept of the image map whereby this defines the area overlaying an image (e.g. GIF). An image map can be processed client or server side. As functionality is built into the web server, performance is good. Image maps can be dynamic. When image maps are used for geographic purposes, the co-ordinate system must be transformed to the geographical origin to conform to the geographical standard of having the origin at the bottom left corner. Web maps are used for location-based services.
Local search is a recent approach to internet searching that incorporates geographical information into search queries so that the links that you return are more relevant to where you are. It developed out of an increasing awareness that many search engine users are using it to look for a business or service in the local area. Local search has stimulated the development of web mapping, which is used either as a tool to use in geographically restricting your search (see Live Search Maps) or as an additional resource to be returned along with search result listings (see Google Maps). It has also led to an increase in the number of small businesses advertising on the web.
In distributed GIS, the term mashup refers to a generic web service which combines content and functionality from disparate sources; mashups reflect a separation of information and presentation. Mashups are increasingly being used in commercial and government applications as well as in the public domain. [43] When used in GIS, it reflects the concept of connecting an application with a mapping service. An examples is combining Google maps with Chicago crime statistics to create the Chicago crime statistics map. Mashups are fast, provide value for money and remove responsibility for the data from the creator.
Second-generation systems provide mashups mainly based on URL parameters, while Third generation systems (e.g. Google Maps) allow customization via script (e.g. JavaScript). [44]
The main standards for Distributed GIS are provided by the Open Geospatial Consortium (OGC). OGC is a non-profit international group that seeks to Web-Enable GIS and, in turn Geo-Enable the web. One of the major issues concerning distributed GIS is the interoperability of the data since it can come in different formats using different projection systems. OGC standards seek to provide interoperability between data and to integrate existing data.
Global System for Mobile Communications (GSM) is a global standard for mobile phones around the world. Networks using the GSM system offer transmission of voice, data, and messages in text and multimedia form and provide web, telenet, FTP, email services, etc., over the mobile network. Almost two million people are now using GSM. Five main standards of GSM exist: GSM 400, GSM 850, GSM 900, GSM-1800 (DCS), and GSM1900 (PCS). GSM 850 and GSM 1900 are used in North America, parts of Latin America, and parts of Africa. In Europe, Asia, and Australia GSM 900/1800 standard is used.
GSM consists of two components: the mobile radio telephone and Subscriber Identity Module. GSM is a cellular network, which is a radio network made up of a number of cells. For each cell, the transmitter (known as a base station) is transmitting and receiving signals. The base station is controlled through the Base Station Controller via the Mobile Switching Centre.
For GSM enhancement General Packet Radio Service (GPRS), a packet-oriented data service for data transmission, and Universal Mobile Telecommunications System (UTMS), the Third Generation (3G) mobile communication system, technology was introduced. Both provide similar services to 2G, but with greater bandwidth and speed.
Wireless Application Protocol (WAP) is a standard for the data transmission of internet content and services. It is a secure specification that allows users to access information instantly via mobile phones, pagers, two-way radios, smartphones, and communicators. WAP supports HTML and XML, and WML language, and is specifically designed for small screens and one-hand navigation without a keyboard. WML is scalable from two-line text displays up to the graphical screens found on smartphones. It is much stricter than HTML and is similar to JavaScript.
A geographic information system (GIS) consists of integrated computer hardware and software that store, manage, analyze, edit, output, and visualize geographic data. Much of this often happens within a spatial database; however, this is not essential to meet the definition of a GIS. In a broader sense, one may consider such a system also to include human users and support staff, procedures and workflows, the body of knowledge of relevant concepts and methods, and institutional organizations.
Environmental Systems Research Institute, Inc., doing business as Esri, is an American multinational geographic information system (GIS) software company headquartered in Redlands, California. It is best known for its ArcGIS products. With 40% market share as of 2011, Esri is one of the world's leading supplier of GIS software, web GIS and geodatabase management applications.
A GIS file format is a standard for encoding geographical information into a computer file, as a specialized type of file format for use in geographic information systems (GIS) and other geospatial applications. Since the 1970s, dozens of formats have been created based on various data models for various purposes. They have been created by government mapping agencies, GIS software vendors, standards bodies such as the Open Geospatial Consortium, informal user communities, and even individual developers.
A GIS software program is a computer program to support the use of a geographic information system, providing the ability to create, store, manage, query, analyze, and visualize geographic data, that is, data representing phenomena for which location is important. The GIS software industry encompasses a broad range of commercial and open-source products that provide some or all of these capabilities within various information technology architectures.
ArcGIS is a family of client, server and online geographic information system (GIS) software developed and maintained by Esri.
Smallworld is the brand name of a portfolio of GIS software provided by GE Digital, a division of General Electric. The software was originally created by the Smallworld company founded in Cambridge, England, in 1989 by Dick Newell and others. Smallworld grew to become the global market leader for GIS in 2010 focused on utilities and communications and remains strong in this sector today. Smallworld was acquired by GE Energy in September 2000.
The Geospatial Data Abstraction Library (GDAL) is a computer software library for reading and writing raster and vector geospatial data formats, and is released under the permissive X/MIT style free software license by the Open Source Geospatial Foundation. As a library, it presents a single abstract data model to the calling application for all supported formats. It may also be built with a variety of useful command line interface utilities for data translation and processing. Projections and transformations are supported by the PROJ library.
The concept of a Geospatial Web may have first been introduced by Dr. Charles Herring in his US DoD paper, An Architecture of Cyberspace: Spatialization of the Internet, 1994, U.S. Army Construction Engineering Research Laboratory.
ArcGIS Server is the core server geographic information system (GIS) software made by Esri. ArcGIS Server is used for creating and managing GIS Web services, applications, and data. ArcGIS Server is typically deployed on-premises within the organization’s service-oriented architecture (SOA) or off-premises in a cloud computing environment.
Digital Earth is the name given to a concept by former US vice president Al Gore in 1998, describing a virtual representation of the Earth that is georeferenced and connected to the world's digital knowledge archives.
Web mapping or an online mapping is the process of using, creating, and distributing maps on the World Wide Web, usually through the use of Web geographic information systems. A web map or an online map is both served and consumed, thus, web mapping is more than just web cartography, it is a service where consumers may choose what the map will show.
A geoportal is a type of web portal used to find and access geographic information and associated geographic services via the Internet. Geoportals are important for effective use of geographic information systems (GIS) and a key element of a spatial data infrastructure (SDI).
Hexagon Geospatial's GeoMedia Professional is a geographic information system (GIS) management solution for map generation and the analysis of geographic information with smart tools that capture and edit spatial data. GeoMedia is used for: creating geographic data; managing geospatial databases; joining business data, location intelligence and geographic data together; creating hard and soft-copy maps; conduct analysis in 'real-time'; base platform for multiple applications, geographic data validation, publishing geospatial information and analyzing mapped information.
Geographic Information Systems (GIS) are an increasingly important component of business, healthcare, security, government, trade, media, transportation and tourism industries and operations in China. GIS software is playing an increasing role in the way Chinese companies analyze and manage business operations.
Spatial contextual awareness consociates contextual information such as an individual's or sensor's location, activity, the time of day, and proximity to other people or objects and devices. It is also defined as the relationship between and synthesis of information garnered from the spatial environment, a cognitive agent, and a cartographic map. The spatial environment is the physical space in which the orientation or wayfinding task is to be conducted; the cognitive agent is the person or entity charged with completing a task; and the map is the representation of the environment which is used as a tool to complete the task.
Neogeography is the use of geographical techniques and tools for personal and community activities or by a non-expert group of users. Application domains of neogeography are typically not formal or analytical.
Geographic information systems (GIS) play a constantly evolving role in geospatial intelligence (GEOINT) and United States national security. These technologies allow a user to efficiently manage, analyze, and produce geospatial data, to combine GEOINT with other forms of intelligence collection, and to perform highly developed analysis and visual production of geospatial data. Therefore, GIS produces up-to-date and more reliable GEOINT to reduce uncertainty for a decisionmaker. Since GIS programs are Web-enabled, a user can constantly work with a decision maker to solve their GEOINT and national security related problems from anywhere in the world. There are many types of GIS software used in GEOINT and national security, such as Google Earth, ERDAS IMAGINE, GeoNetwork opensource, and Esri ArcGIS.
Internet GIS, or Internet geographic information system (GIS), is a term that refers to a broad set of technologies and applications that employ the Internet to access, analyze, visualize, and distribute spatial data. Internet GIS is an outgrowth of traditional GIS, and represents a shift from conducting GIS on an individual computer to working with remotely distributed data and functions. Two major issues in GIS are accessing and distributing spatial data and GIS outputs. Internet GIS helps to solve that problem by allowing users to access vast databases impossible to store on a single desktop computer, and by allowing rapid dissemination of both maps and raw data to others. These methods include both file sharing and email. This has enabled the general public to participate in map creation and make use of GIS technology.
Web GIS, or Web Geographic Information Systems, are GIS that employ the World Wide Web to facilitate the storage, visualization, analysis, and distribution of spatial information over the Internet. The World Wide Web, or the Web, is an information system that uses the internet to host, share, and distribute documents, images, and other data. Web GIS involves using the World Wide Web to facilitate GIS tasks traditionally done on a desktop computer, as well as enabling the sharing of maps and spatial data. While Web GIS and Internet GIS are sometimes used interchangeably, they are different concepts. Web GIS is a subset of Internet GIS, which is itself a subset of distributed GIS, which itself is a subset of broader Geographic information system. The most common application of Web GIS is Web mapping, so much so that the two terms are often used interchangeably in much the same way as Digital mapping and GIS. However, Web GIS and web mapping are distinct concepts, with web mapping not necessarily requiring a Web GIS.
A Geodatabase is a proprietary GIS file format developed in the late 1990s by Esri to represent, store, and organize spatial datasets within a geographic information system. A geodatabase is both a logical data model and the physical implementation of that logical model in several proprietary file formats released during the 2000s. The geodatabase design is based on the spatial database model for storing spatial data in relational and object-relational databases. Given the dominance of Esri in the GIS industry, the term "geodatabase" is used by some as a generic trademark for any spatial database, regardless of platform or design.