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ArcGIS
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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, and perform basic spatial analysis; ArcEditor which, in addition to the functionality of ArcView, includes more advanced tools for manipulation of shapefiles and geodatabases; or ArcInfo the most advanced version of ArcGIS, which includes added capabilities for data manipulation, editing, and analysis.
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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, and perform basic spatial analysis; ArcEditor which, in addition to the functionality of ArcView, includes more advanced tools for manipulation of shapefiles and geodatabases; or ArcInfo the most advanced version of ArcGIS, which includes added capabilities for data manipulation, editing, and analysis. There are also server-based ArcGIS products, as well as ArcGIS products for PDAs. Extensions can be purchased separately to increase the functionality of ArcGIS.
Product history
Prior to the ArcGIS suite, ESRI had focused its software development on the command line Arc/INFO workstation program and several Graphical User Interface-based products such as the ArcView GIS 3.x desktop program. Other ESRI products included MapObjects, a programming library for developers, and ArcSDE as a relational database management system. The various products had branched out into multiple source trees and did not integrate well with one another. In January 1997, ESRI decided to revamp its GIS software platform, creating a single integrated software architecture.
ArcGIS 8.x
In late 1999, ESRI released ArcGIS 8.0, which ran on the Microsoft Windows operating system. ArcGIS combined the visual user-interface aspect of ArcView GIS 3.x interface with some of the power from the Arc/INFO version 7.2 workstation. This pairing resulted in a new software suite called ArcGIS, which included the command-line ArcInfo workstation (v8.0) and a new graphical user interface application called ArcMap (v8.0) incorporating some of the functionality of ArcInfo with a more intuitive interface, as well as an ArcGIS file management application called ArcCatalog (v8.0). The release of the ArcGIS suite constituted a major change in ESRI's software offerings, aligning all their client and server products under one software architecture known as ArcGIS, developed using Microsoft Windows COM standards.
One major difference is the programming (scripting) languages available to customize or extend the software to suit particular user needs. In the transition to ArcGIS, ESRI dropped support of its application-specific scripting languages, Avenue and the ARC Macro Language (AML), in favour of Visual Basic for Applications scripting and open access to ArcGIS components using the Microsoft COM standards. ArcGIS is designed to store data in a proprietary RDBMS format, known as geodatabase. ArcGIS 8.x introduced other new features, including on-the-fly map projections, and annotation in the database.
Updates of ArcView 3.x extensions, including 3D Analyst and Spatial Analyst, came later with release of ArcGIS 8.1, which was unveiled at the ESRI International User Conference in 2000. ArcGIS 8.1 was officially released on April 24 2001. Other new extenstions were made available with ArcGIS 8.1, including GeoStatistical Analyst. ArcGIS 8.1 also added the ability to access data online, directly from the Geography Network site or other ArcIMS map services. ArcGIS 8.3 was introduced in 2002, adding topology to geodatabases, which was a feature originally available only with ArcInfo coverages.
ArcGIS 9.x
ArcGIS 9.0 was released in May 2004, which included ArcGIS Server and ArcGIS Engine for developers. The current version of the ArcGIS software is 9.3. The ArcGIS 9 release includes a geoprocessing environment that allows execution of traditional GIS processing tools (such as clipping, overlay, and spatial analysis) interactively or from any scripting language that supports COM standards. Although the most popular of these is Python, others have been used, especially Perl and VBScript. ArcGIS 9 also includes a visual programming environment called ModelBuilder that allows users to graphically link geoprocessing tools into new tools called models. These models can be executed directly or exported to scripting languages which can then execute in batch mode (launched from a command line), or they can undergo further editing to add branching or looping.
In March 2008, ESRI began distributing beta versions of ArcGIS 9.3. The new version of ArcGIS Desktop has new modeling tools and geostatistical error tracking features, while ArcGIS Server has improved performance, and support for role-based security. There also are new JavaScript APIs that can be used to create mashups, and integrated with either Google Maps or Microsoft Virtual Earth. ArcGIS 9.3 is expected out sometime later in the spring or summer of 2008. At the 2008 ESRI Developers Summit, there was little emphasis on ArcIMS, except for one session on transitioning from ArcIMS to ArcGIS Server-based applications, indicating a change in focus for ESRI with ArcGIS 9.3 for web-based mapping applications.
Geodatabase
Older ESRI products, including ArcView 3.x, worked with data in the shapefile format. ArcInfo Workstation handled coverages, which stored topology information about the spatial data. Coverages, which were introduced in 1981 when ArcInfo was first released, has limitations in how it handles types of features. Some features, such as roads with street intersections or overpasses and underpasses, should be handled differently than other types of features.
ArcGIS is built around the geodatabase, which uses an object-relational database approach for storing spatial data. A geodatabase is a "container" for holding datasets, tying together the spatial features with attributes. The geodatabase can also contain topology information, and can model behavior of features, such as road intersections, with rules on how features relate to one another. When working with geodatabases, it is important to understand about feature classes which are a set of features, represented with points, lines, or polygons. With shapefiles, each file can only handle one type of feature. A geodatabase can store multiple feature classes or type of features within one file.
Geodatabases in ArcGIS can be stored in three different ways including as a "file geodatabase", "personal geodatabase", and "ArcSDE geodatabase". Personal geodatabases store data in Microsoft Access files, using a BLOB field to store the geometry data. The OGR library is able to handle this file type, to convert it to other file formats. Database administration tasks for personal geodatabases, such as managing users and creating backups, can be done through ArcCatalog. Personal geodatabases, which are based on Microsoft Access, run only on Microsoft Windows and have a 2 gigabyte size limit. Enterprise (multi-user) level geodatabases are handled using ArcSDE, which interfaces with high-end DBMS such as Oracle, Microsoft SQL Server, DB2 and Informix to handle database management aspects, while ArcGIS deals with spatial data management. Enterprise level geodatabases support database replication, versioning and transaction management, and is cross-platform compatible, able to run on Linux, Windows, and Solaris.
Components and product levels
ArcGIS consists of Desktop GIS products, as well as GIS products that run on a server, or on a mobile device.
ArcGIS Desktop
Product levels
ArcGIS Desktop is available at different product levels, with increasing functionality.
- ArcReader (freeware, viewer) is a basic data viewer for maps and GIS data published in the proprietary ESRI format using ArcGIS Publisher. The software also provides some basic tools for map viewing, printing and querying of spatial data. ArcReader is included with any of the ArcGIS suite of products, and is also available for free to download. ArcReader only works with preauthored published map files, created with ArcGIS Publisher.
- ArcEditor is the midlevel software suite designed for advanced editing of spatial data published in the proprietary ESRI format. It provides tools for the creation of map and spatial data used in GIS, including the ability of editing geodatabase files and data, multiuser geodatabase editing, versioning, raster data editing and vectorization, advanced vector data editing, managing coverages, coordinated geometry (COGO), and editing geometric networks. ArcEditor is not intended for advanced spatial analysis.
- ArcInfo allows users the most flexibility and control in "all aspects of data building, modeling, analysis, and map display." ArcInfo includes increased capability in the areas of spatial analysis, geoprocessing, data management, and others.
Other desktop GIS software include ArcGIS Explorer and ArcGIS Engine. ArcGIS Explorer is a GIS viewer which can work as a client for ArcGIS Server, ArcIMS, ArcWeb Services and Web Map Service (WMS).
Components
ArcGIS Desktop consists of several integrated applications, including ArcMap, ArcCatalog, ArcToolbox, and ArcGlobe. ArcCatalog is the data management application, used to browse datasets and files on one's computer, database, or other sources. In addition to showing what data is available, ArcCatalog also allows users to preview the data on a map. ArcCatalog also provides the ability to view and manage metadata for spatial datasets. ArcMap is the application used to view, edit and query geospatial data, and create maps. The ArcMap inferface has two main sections, including a table of contents on the left and the data frame(s) which display the map. Items in the table of contents correspond with layers on the map. ArcToolbox contains geoprocessing, data conversion, and analysis tools, along with much of the functionality in ArcInfo. It is also possible to use batch processing with ArcToolbox, for frequently repeated tasks.
Extensions
There are a number of software extensions for ArcGIS Desktop to provided added functionality, including 3D Analyst, Spatial Analyst, Network Analyst, Survey Analyst, Tracking Analyst and Geostatistical Analyst. Advanced map labeling is available with the Maplex extension, as an add-on to ArcView and ArcEditor and is bundled with ArcInfo. Numerous extensions have also been developed by third-parties, such as XTools and MAP2PDF for creating georeferenced pdfs (GeoPDF),, ERDAS' Image Analysis and Stereo Analyst for ArcGIS, and ISM's PurVIEW, which converts Arc- desktops into precise stereo-viewing windows to work with geo-referenced stereoscopic image models for accurate geodatabase-direct editing or feature digitizing.
Other products
ArcGIS Mobile and ArcPad are products designed for mobile devices. ArcGIS Mobile is a software development kit for developers to use to create applications for mobile devices, such as smartphones or tablet PCs. If connected to the Internet, mobile applications can connect to ArcGIS Server to access or update data.
Server GIS products include ArcIMS (web mapping server), ArcGIS Server and ArcGIS Image Server. As with ArcGIS Desktop, ArcGIS Server is available at different product levels, including Basic, Standard, and Advanced Editions. ArcGIS Server comes with SQL Server Express DBMS embedded, and can work with enterprise DBMS such as SQL Server Enterprise and Oracle. The ESRI Developer Network (EDN) includes ArcObjects and other tools for building custom software applications, and ArcGIS Engine provides a programming interface for developers.
Sales
ArcGIS Desktop products and ArcPad are available with a single-use license. Most products are also available with concurrent-use license, while development server licenses and other types of software licenses are available for other products. Single-use products can be purchased online from the ESRI Store, while all ArcGIS products are available through a sales representative or reseller. Annual software maintenance and support is also available for ArcGIS. While there are alternative products available from other traditional vendors such as MapInfo and Intergraph, ESRI has a dominant share of the GIS software market with its software used by 78% of GIS professionals.
Criticisms
ESRI's change to the ArcGIS platform has rendered an extensive range of user-developed and third-party add-on software and scripts that worked with the older ESRI software architectures incompatible with ArcGIS. Because of the changes in scripting capability, functionality, operating system choices (the ArcGIS Desktop software is developed exclusively for the Microsoft Windows operating system), and the significantly larger system resources required by the ArcGIS system, a substantial user base resists migrating to ArcGIS. ESRI has continued support for these users. ArcView 3.x is still available for purchase, and ArcInfo Workstation is still included in a full ArcGIS ArcInfo license to provide some editing and file conversion functionality that has not been included to date in ArcGIS.
ArcMap and other ArcGIS applications have a tendency to crash from time to time. ArcGIS Desktop 9.1 also had bugs when one tried exporting maps as PDF files. With ArcGIS 9.2 (SP4) on Microsoft Windows Vista, there are a number of additional bugs. ESRI has issued a number of service packs for ArcGIS Desktop and other products, which include numerous bug fixes, along with feature enhancements. Other issues with ArcGIS include high prices for the products, proprietary formats, and difficulties of porting data between ESRI and other GIS software.
See also
- ArcView 3.x Covering the older version of ArcView
External links
- - ESRI
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- , USA Today, August 3 2004
- - International Journal of Geoinformatics, June 2007
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- - Craig Gillgrass and Erik Hoel (pdf)
- - A VerySpatial Podcast, Episode 57, August 20 2006
- - Erik Hoel, Sudhakar Menon, Scott Morehouse
- - 2006 ESRI Developers Summit
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