In geometry, an affine transformation, affine map or an affinity is a function between affine spaces which preserves points, straight lines and planes. Sets of parallel lines remain parallel after an affine transformation. An affine transformation does not preserve angles between lines or distances between points, though it does preserve ratios of distances between points lying on a straight line. Examples of affine transformations include translation, homothety, similarity transformation, rotation, shear mapping, compositions of them in any combination and sequence. If X and Y are affine spaces every affine transformation f: X → Y is of the form x ↦ M x + b, where M is a linear transformation on the space X, x is a vector in X, b is a vector in Y. Unlike a purely linear transformation, an affine map need not preserve the zero point in a linear space. Thus, every linear transformation is affine. All Euclidean spaces are affine. In affine coordinates, which include Cartesian coordinates in Euclidean spaces, each output coordinate of an affine map is a linear function of all input coordinates.
Another way to deal with affine transformations systematically is to select a point as the origin. An affine map f: A → B between two affine spaces is a map on the points that acts linearly on the vectors. In symbols, f determines a linear transformation φ such that, for any pair of points P, Q ∈ A: f f → = φ or f − f = φ. We can interpret this definition in a few other ways. If an origin O ∈ A is chosen, B denotes its image f ∈ B this means that for any vector x →: f: ↦. If an origin O ′ ∈ B is chosen, this can be decomposed as an affine transformation g: A → B that sends O ↦ O ′, namely g: ↦,followed by the translation by a vector b → = O ′ B →; the conclusion is that, intuitively, f consists of a linear map. Given two affine spaces A and B, over the same field, a function f: A → B is an affine map if and only if for every family i ∈ I of weighted points in A such that ∑ i ∈ I λ i = 1,we have f = ∑ i ∈ I λ i f. I
Geographic information system
A geographic information system is a system designed to capture, manipulate, analyze and present spatial or geographic data. GIS applications are tools that allow users to create interactive queries, analyze spatial information, edit data in maps, present the results of all these operations. GIS sometimes refers to geographic information science, the science underlying geographic concepts and systems. GIS can refer to a number of different technologies, processes and methods, it is attached to many operations and has many applications related to engineering, management, transport/logistics, telecommunications, business. For that reason, GIS and location intelligence applications can be the foundation for many location-enabled services that rely on analysis and visualization. GIS can relate unrelated information by using location as the key index variable. Locations or extents in the Earth space–time may be recorded as dates/times of occurrence, x, y, z coordinates representing, longitude and elevation, respectively.
All Earth-based spatial–temporal location and extent references should be relatable to one another and to a "real" physical location or extent. This key characteristic of GIS has begun to open new avenues of scientific inquiry; the first known use of the term "geographic information system" was by Roger Tomlinson in the year 1968 in his paper "A Geographic Information System for Regional Planning". Tomlinson is acknowledged as the "father of GIS". One of the first applications of spatial analysis in epidemiology is the 1832 "Rapport sur la marche et les effets du choléra dans Paris et le département de la Seine"; the French geographer Charles Picquet represented the 48 districts of the city of Paris by halftone color gradient according to the number of deaths by cholera per 1,000 inhabitants. In 1854 John Snow determined the source of a cholera outbreak in London by marking points on a map depicting where the cholera victims lived, connecting the cluster that he found with a nearby water source.
This was one of the earliest successful uses of a geographic methodology in epidemiology. While the basic elements of topography and theme existed in cartography, the John Snow map was unique, using cartographic methods not only to depict but to analyze clusters of geographically dependent phenomena; the early 20th century saw the development of photozincography, which allowed maps to be split into layers, for example one layer for vegetation and another for water. This was used for printing contours – drawing these was a labour-intensive task but having them on a separate layer meant they could be worked on without the other layers to confuse the draughtsman; this work was drawn on glass plates but plastic film was introduced, with the advantages of being lighter, using less storage space and being less brittle, among others. When all the layers were finished, they were combined into one image using a large process camera. Once color printing came in, the layers idea was used for creating separate printing plates for each color.
While the use of layers much became one of the main typical features of a contemporary GIS, the photographic process just described is not considered to be a GIS in itself – as the maps were just images with no database to link them to. Two additional developments are notable in the early days of GIS: Ian McHarg's publication "Design with Nature" and its map overlay method and the introduction of a street network into the U. S. Census Bureau's DIME system. Computer hardware development spurred by nuclear weapon research led to general-purpose computer "mapping" applications by the early 1960s; the year 1960 saw the development of the world's first true operational GIS in Ottawa, Canada, by the federal Department of Forestry and Rural Development. Developed by Dr. Roger Tomlinson, it was called the Canada Geographic Information System and was used to store and manipulate data collected for the Canada Land Inventory – an effort to determine the land capability for rural Canada by mapping information about soils, recreation, waterfowl and land use at a scale of 1:50,000.
A rating classification factor was added to permit analysis. CGIS was an improvement over "computer mapping" applications as it provided capabilities for overlay 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" for his use of overlays in promoting the spatial analysis of convergent geographic data. CGIS built a large 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 datasets; the CGIS was never available commercially. In 1964 Howard T. Fisher formed the Laboratory for Computer Graphics and Spatial Analysis at the Harvard Graduate School of Design, where a number of important theoretical concepts in spatial data handling were developed, which by the 1970s had distributed seminal software code and systems, such as SYMAP, GRID, ODYSSEY – that served as sources for subsequent commercial development—to universities, research centers and corporations worldwide.
By the late 1970s two public domain GIS systems were in development, by the early 1980s, M&S Computing (late
A gazetteer is a geographical dictionary or directory used in conjunction with a map or atlas. It contains information concerning the geographical makeup, social statistics and physical features of a country, region, or continent. Content of a gazetteer can include a subject's location, dimensions of peaks and waterways, gross domestic product and literacy rate; this information is divided into topics with entries listed in alphabetical order. Ancient Greek gazetteers are known to have existed since the Hellenistic era; the first known Chinese gazetteer was released by the first century, with the age of print media in China by the ninth century, the Chinese gentry became invested in producing gazetteers for their local areas as a source of information as well as local pride. The geographer Stephanus of Byzantium wrote a geographical dictionary in the sixth century which influenced European compilers. Modern gazetteers can be found in reference sections of most libraries as well as on the internet.
The Oxford English Dictionary defines a "gazetteer" as a "geographical index or dictionary". It includes as an example a work by the British historian Laurence Echard in 1693 that bore the title "The Gazetteer's: or Newsman's Interpreter: Being a Geographical Index". Echard wrote that the title "Gazetteer's" was suggested to him by a "very eminent person" whose name he chose not to disclose. For Part II of this work published in 1704, Echard referred to the book as "the Gazeteer"; this marked the introduction of the word "gazetteer" into the English language. Historian Robert C. White suggests that the "very eminent person" written of by Echard was his colleague Edmund Bohun, chose not to mention Bohun because he became associated with the Jacobite movement. Since the 18th century, the word "gazetteer" has been used interchangeably to define either its traditional meaning or a daily newspaper, such as the London Gazetteer. Gazetteers are categorized by the type, scope, of the information presented.
World gazetteers consist of an alphabetical listing of countries, with pertinent statistics for each one, with some gazetteers listing information on individual cities, towns and other settlements of varying sizes. Short-form gazetteers used in conjunction with computer mapping and GIS systems, may contain a list of place-names together with their locations in latitude and longitude or other spatial referencing systems. Short-form gazetteers appear as a place–name index in the rear of major published atlases. Descriptive gazetteers may include lengthy textual descriptions of the places they contain, including explanation of industries, geography, together with historical perspectives, maps and/or photographs. Thematic gazetteers list places or geographical features by theme, their common element is that the geographical location is an important attribute of the features listed. Gazetteer editors gather facts and other information from official government reports, the census, chambers of commerce, together with numerous other sources, organise these in digest form.
In his journal article "Alexander and the Ganges", the 20th-century historian W. W. Tarn calls a list and description of satrapies of Alexander's Empire written between 324 and 323 BC as an ancient gazetteer. Tarn notes that the document is dated no than June 323 BC, since it features Babylon as not yet partitioned by Alexander's generals, it was revised by the Greek historian Diodorus Siculus in the 1st century BC. In the 1st century BC, Dionysius of Halicarnassus mentioned the chronicle-type format of the writing of the logographers in the age before the founder of the Greek historiographic tradition, saying "they did not write connected accounts but instead broke them up according to peoples and cities, treating each separately". Historian Truesdell S. Brown asserts that what Dionysius describes in this quote about the logographers should be categorized not as a true "history" but rather as a gazetteer. While discussing the Greek conception of the river delta in ancient Greek literature, Francis Celoria notes that both Ptolemy and Pausanias of the 2nd century AD provided gazetteer information on geographical terms.
Predating Greek gazetteers were those made in ancient Egypt. Although she does not label the document as a gazetteer, Penelope Wilson describes an ancient Egyptian papyrus found at the site of Tanis, Egypt which provides the following for each administrative area of Egypt at the time:...the name of a nome capital, its sacred barque, its sacred tree, its cemetery, the date of its festival, the names of forbidden objects, the local god and lake of the city. This interesting codification of data made by a priest, is paralleled by similar editions of data on the temple walls at Edfu, for example; the Domesday Book initiated by William I of England in 1086 was a government survey on all the administrative counties of England. In the survey, numerous English castles were listed. However, the Domesday Book does detail the fact that out of 3,558 registered houses destroyed in 112 different boroughs listed, 410 of these destroyed houses were the direct result of castle construction and expansion. In 1316 the Nomina Villarum survey was initiated by Edward II of
The metre or meter is the base unit of length in the International System of Units. The SI unit symbol is m; the metre is defined as the length of the path travelled by light in vacuum in 1/299 792 458 of a second. The metre was defined in 1793 as one ten-millionth of the distance from the equator to the North Pole – as a result the Earth's circumference is 40,000 km today. In 1799, it was redefined in terms of a prototype metre bar. In 1960, the metre was redefined in terms of a certain number of wavelengths of a certain emission line of krypton-86. In 1983, the current definition was adopted; the imperial inch is defined as 0.0254 metres. One metre is about 3 3⁄8 inches longer than a yard, i.e. about 39 3⁄8 inches. Metre is the standard spelling of the metric unit for length in nearly all English-speaking nations except the United States and the Philippines, which use meter. Other Germanic languages, such as German and the Scandinavian languages spell the word meter. Measuring devices are spelled "-meter" in all variants of English.
The suffix "-meter" has the same Greek origin as the unit of length. The etymological roots of metre can be traced to the Greek verb μετρέω and noun μέτρον, which were used for physical measurement, for poetic metre and by extension for moderation or avoiding extremism; this range of uses is found in Latin, French and other languages. The motto ΜΕΤΡΩ ΧΡΩ in the seal of the International Bureau of Weights and Measures, a saying of the Greek statesman and philosopher Pittacus of Mytilene and may be translated as "Use measure!", thus calls for both measurement and moderation. In 1668 the English cleric and philosopher John Wilkins proposed in an essay a decimal-based unit of length, the universal measure or standard based on a pendulum with a two-second period; the use of the seconds pendulum to define length had been suggested to the Royal Society in 1660 by Christopher Wren. Christiaan Huygens had observed that length to be 39.26 English inches. No official action was taken regarding these suggestions.
In 1670 Gabriel Mouton, Bishop of Lyon suggested a universal length standard with decimal multiples and divisions, to be based on a one-minute angle of the Earth's meridian arc or on a pendulum with a two-second period. In 1675, the Italian scientist Tito Livio Burattini, in his work Misura Universale, used the phrase metro cattolico, derived from the Greek μέτρον καθολικόν, to denote the standard unit of length derived from a pendulum; as a result of the French Revolution, the French Academy of Sciences charged a commission with determining a single scale for all measures. On 7 October 1790 that commission advised the adoption of a decimal system, on 19 March 1791 advised the adoption of the term mètre, a basic unit of length, which they defined as equal to one ten-millionth of the distance between the North Pole and the Equator. In 1793, the French National Convention adopted the proposal. In 1791, the French Academy of Sciences selected the meridional definition over the pendular definition because the force of gravity varies over the surface of the Earth, which affects the period of a pendulum.
To establish a universally accepted foundation for the definition of the metre, more accurate measurements of this meridian were needed. The French Academy of Sciences commissioned an expedition led by Jean Baptiste Joseph Delambre and Pierre Méchain, lasting from 1792 to 1799, which attempted to measure the distance between a belfry in Dunkerque and Montjuïc castle in Barcelona to estimate the length of the meridian arc through Dunkerque; this portion of the meridian, assumed to be the same length as the Paris meridian, was to serve as the basis for the length of the half meridian connecting the North Pole with the Equator. The problem with this approach is that the exact shape of the Earth is not a simple mathematical shape, such as a sphere or oblate spheroid, at the level of precision required for defining a standard of length; the irregular and particular shape of the Earth smoothed to sea level is represented by a mathematical model called a geoid, which means "Earth-shaped". Despite these issues, in 1793 France adopted this definition of the metre as its official unit of length based on provisional results from this expedition.
However, it was determined that the first prototype metre bar was short by about 200 micrometres because of miscalculation of the flattening of the Earth, making the prototype about 0.02% shorter than the original proposed definition of the metre. Regardless, this length became the French standard and was progressively adopted by other countries in Europe; the expedition was fictionalised in Le mètre du Monde. Ken Alder wrote factually about the expedition in The Measure of All Things: the seven year odyssey and hidden error that transformed the world. In 1867 at the second general conference of the International Association of Geodesy held in Berlin, the question of an international standard unit of length was discussed in order to combine the measurements made in different countries to determine the size and shape of the Earth; the conference recommended the adoption of the metre and the creation of an internatio
A filename is a name used to uniquely identify a computer file stored in a file system. Different file systems impose different restrictions on filename lengths and the allowed characters within filenames. A filename may include one or more of these components: host – network device that contains the file device – hardware device or drive directory – directory tree file – base name of the file type – indicates the content type of the file version – revision or generation number of the fileThe components required to identify a file varies across operating systems, as does the syntax and format for a valid filename. Discussions of filenames are complicated by a lack of standardization of the term. Sometimes "filename" is used to mean the entire name, such as the Windows name c:\directory\myfile.txt. Sometimes, it will be used to refer to the components, so the filename in this case would be myfile.txt. Sometimes, it is a reference that excludes an extension, so the filename would be just myfile.
Around 1962, the Compatible Time-Sharing System introduced the concept of a file. Around this same time appeared the dot as a filename extension separator, the limit to three letter extensions might have come from 16-bit RAD50 character encoding limits. Traditionally, most operating system supported filenames with only uppercase alphanumeric characters, but as time progressed, the number of characters allowed increased; this led to compatibility problems. In 1985, RFC 959 defined a pathname to be the character string that must be entered into a file system by a user in order to identify a file. Around 1995, VFAT, an extension to the MS-DOS FAT filesystem, was introduced in Windows 95 and Windows NT, it allowed mixed-case Unicode long filenames, in addition to classic "8.3" names. One issue was migration to Unicode. For this purpose, several software companies provided software for migrating filenames to the new Unicode encoding. Microsoft provided migration transparent for the user throughout the vfat technology Apple provided "File Name Encoding Repair Utility v1.0".
The Linux community provided “convmv”. Mac OS X 10.3 marked Apple's adoption of Unicode 3.2 character decomposition, superseding the Unicode 2.1 decomposition used previously. This change caused problems for developers writing software for Mac OS X. An absolute reference includes all directory levels. In some systems, a filename reference that does not include the complete directory path defaults to the current working directory; this is a relative reference. One advantage of using a relative reference in program configuration files or scripts is that different instances of the script or program can use different files; this makes an relative path composed of a sequence of filenames. Unix-like file systems allow a file to have more than one name. Windows supports hard links on NTFS file systems, provides the command fsutil in Windows XP, mklink in versions, for creating them. Hard links are different from classic Mac OS/macOS aliases, or symbolic links; the introduction of LFNs with VFAT allowed filename aliases.
For example, longfi~1.??? with a maximum of eight plus three characters was a filename alias of "long file name.???" as a way to conform to 8.3 limitations for older programs. This property was used by the move command algorithm that first creates a second filename and only removes the first filename. Other filesystems, by design, provide only one filename per file, which guarantees that alteration of one filename's file does not alter the other filename's file; some filesystems restrict the length of filenames. In some cases, these lengths apply to the entire file name, as in 44 characters on IBM S/370. In other cases, the length limits may apply to particular portions of the filename, such as the name of a file in a directory, or a directory name. For example, 9, 11, 14, 21, 31, 30, 15, 44, or 255 characters or bytes. Length limits result from assigning fixed space in a filesystem to storing components of names, so increasing limits requires an incompatible change, as well as reserving more space.
A particular issue with filesystems that store information in nested directories is that it may be possible to create a file with a complete pathname that exceeds implementation limits, since length checking may apply only to individual parts of the name rather than the entire name. Many Windows applications are limited to a MAX_PATH value of 260, but Windows file names can exceed this limit. Many file systems, including FAT, NTFS, VMS systems, allow a filename extension that consists of one or more characters following the last period in the filename, dividing the filename into two parts: a base name or stem and an extension or suffix used by some applications to indicate the file type. Multiple output files created by an application use various extensions. For example, a compiler might use the extension FOR for source input file, OBJ for the object output and LST for the listing. Although there are some common extensions, they are arbitrary and a different application might use REL and RPT.
On filesystems that do not segregate the extension, files will have a longer extension such as html. There is no general encoding standard for filenames
JPEG is a used method of lossy compression for digital images for those images produced by digital photography. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG achieves 10:1 compression with little perceptible loss in image quality. JPEG compression is used in a number of image file formats. JPEG/Exif is the most common image format used by digital cameras and other photographic image capture devices; these format variations are not distinguished, are called JPEG. The term "JPEG" is an initialism/acronym for the Joint Photographic Experts Group, which created the standard; the MIME media type for JPEG is image/jpeg, except in older Internet Explorer versions, which provides a MIME type of image/pjpeg when uploading JPEG images. JPEG files have a filename extension of.jpg or.jpeg. JPEG/JFIF supports a maximum image size of 65,535×65,535 pixels, hence up to 4 gigapixels for an aspect ratio of 1:1. "JPEG" stands for Joint Photographic Experts Group, the name of the committee that created the JPEG standard and other still picture coding standards.
The "Joint" stood for ISO TC97 WG8 and CCITT SGVIII. In 1987, ISO TC 97 became ISO/IEC JTC1 and, in 1992, CCITT became ITU-T. On the JTC1 side, JPEG is one of two sub-groups of ISO/IEC Joint Technical Committee 1, Subcommittee 29, Working Group 1 – titled as Coding of still pictures. On the ITU-T side, ITU-T SG16 is the respective body; the original JPEG Group was organized in 1986, issuing the first JPEG standard in 1992, approved in September 1992 as ITU-T Recommendation T.81 and, in 1994, as ISO/IEC 10918-1. The JPEG standard specifies the codec, which defines how an image is compressed into a stream of bytes and decompressed back into an image, but not the file format used to contain that stream; the Exif and JFIF standards define the used file formats for interchange of JPEG-compressed images. JPEG standards are formally named as Information technology – Digital compression and coding of continuous-tone still images. ISO/IEC 10918 consists of the following parts: Ecma International TR/98 specifies the JPEG File Interchange Format.
The JPEG compression algorithm operates at its best on photographs and paintings of realistic scenes with smooth variations of tone and color. For web usage, where reducing the amount of data used for an image is important for responsive presentation, JPEG's compression benefits make JPEG popular. JPEG/Exif is the most common format saved by digital cameras. However, JPEG is not well suited for line drawings and other textual or iconic graphics, where the sharp contrasts between adjacent pixels can cause noticeable artifacts; such images are better saved in a lossless graphics format such as TIFF, GIF, PNG, or a raw image format. The JPEG standard includes a lossless coding mode; as the typical use of JPEG is a lossy compression method, which reduces the image fidelity, it is inappropriate for exact reproduction of imaging data. JPEG is not well suited to files that will undergo multiple edits, as some image quality is lost each time the image is recompressed if the image is cropped or shifted, or if encoding parameters are changed – see digital generation loss for details.
To prevent image information loss during sequential and repetitive editing, the first edit can be saved in a lossless format, subsequently edited in that format finally published as JPEG for distribution. JPEG uses a lossy form of compression based on the discrete cosine transform; this mathematical operation converts each frame/field of the video source from the spatial domain into the frequency domain. A perceptual model based loosely on the human psychovisual system discards high-frequency information, i.e. sharp transitions in intensity, color hue. In the transform domain, the process of reducing information is called quantization. In simpler terms, quantization is a method for optimally reducing a large number scale into a smaller one, the transform-domain is a convenient representation of the image because the high-frequency coefficients, which contribute less to the overall picture than other coefficients, are characteristically small-values with high compressibility; the quantized coefficients are sequenced and losslessly packed into the output bitstream.
Nearly all software implementations of JPEG permit user control over the compression ratio, allowing the user to trade off picture-quality for smaller file size. In embedded applications, the parameters are fixed for the application; the compression method is lossy, meaning that some original image information is lost and cannot be restored affecting image quality. There is an optional lossless mode defined in the JPEG standard. However, this mode is not supported in products. There is an interlaced progressive JPEG format, in which data is compressed in multiple passes of progressively higher detail; this is ideal for large images that will be displayed while downloading over a slow connection, allowing a reasonable preview after receiving only a portion of the data. However, support for progressive JPEGs is not universal; when progressive JPEGs are received by programs that do not support them (such
Esri is an international supplier of geographic information system software, web GIS and geodatabase management applications. The company is headquartered in California; the company was founded as Environmental Systems Research Institute in 1969 as a land-use consulting firm. Esri products have 40.7% of the global market share. In 2014, Esri had a 43 percent share of the GIS software market worldwide, more than any other vendor; the company has 10 regional offices in the U. S. and a network of 80+ international distributors, with about a million users in 200 countries. The firm has 3,800 employees globally, is held by its founders. In 2006, revenues were about $660 million. In a 2016 Investor's Business Daily article, Esri's annual revenues were indicated to be $1.1 Billion, from 300,000 customers. The company hosts an annual International User's Conference, first held on the Redlands campus in 1981 with 16 attendees; the User's Conference has been held in San Diego at the San Diego Convention Center since 1997.
An estimated 15,000 users from 131 countries attended in 2012. Jack and Laura Dangermond founded Esri in 1969. Jack Dangermond is the current president. According to the company, Esri is pronounced as a word,'ez-ree'; some distributors outside of the USA such as Esri Canada market themselves with the'ess-ree' pronunciation followed by the country name. Esri uses the name ArcGIS to refer to its suite of GIS software products, which operate on desktop and mobile platforms. ArcGIS includes developer products and web services. In a general sense, the term GIS describes any information system that integrates, edits, analyzes and displays geographic information for informing decision making; the term GIS-Centric, has been defined as the use of the Esri ArcGIS geodatabase as the asset and feature data repository central to computerized maintenance management systems as a part of enterprise asset management and analytical software systems. GIS-centric certification criteria have been defined by NAGCS, the National Association of GIS-Centric Solutions.
As of February 2018, the company's desktop GIS suite is ArcGIS for Desktop version 10.6. ArcGIS for Desktop consists of several integrated applications, including ArcMap, ArcCatalog, ArcToolbox, ArcScene, ArcGlobe, ArcGIS Pro; the suite's main components, ArcMap, ArcCatalog and ArcToolbox, allow users to author, map, manage and publish geographic information. The product suite is available in three levels of licensing: Basic and Advanced. Basic provides a basic set of GIS capabilities suitable for many GIS applications. Standard, at added cost, allows more extensive data editing and manipulation, including server geodatabase editing. Advanced, at the high end, provides full, advanced analysis and data management capabilities, including geostatistical and topological analysis tools. Additionally, ArcGIS is compatible with following OGC standards: WCS, GFS and various others. ArcGIS Explorer, ArcReader, ArcExplorer are basic freeware applications for viewing GIS data. ArcGIS for Desktop Extensions are available, including Spatial Analyst for raster analysis, 3D Analyst for terrain mapping and analysis.
Other more specialized extensions are available from third parties. Esri's original product, ARC/INFO, was a command line GIS product available on minicomputers on UNIX workstations. In 1992, a GUI GIS, ArcView GIS, was introduced. Over time, both products were offered in Windows versions, ArcView as a Macintosh product; the names ArcView and ArcInfo are now used to name different levels of licensing in ArcGIS for Desktop, less refer to these original software products. The Windows version of ArcGIS is now the only ArcGIS for Desktop platform, undergoing new development for future product releases. Server GIS products provide GIS functionality and data deployed from a central environment. ArcGIS for Server is an Internet application service, used to extend the functionality of ArcGIS for Desktop software to a browser based environment, it is available on Linux as well as Windows. ArcSDE is used as a Relational database management system connector for other Esri software to store and retrieve GIS data within a commercially available database: it can be used with Oracle, PostgreSQL, DB2, Informix and Microsoft SQL Server databases.
It supports its native SDE binary data format, Oracle Spatial, ST_geometry. ArcIMS provides browser-based access to GIS; as of ArcGIS 10.1, ArcIMS has been depreciated in favour of ArcGIS for Server, but there are still many instances of ArcIMS in production environments. Other server-based products include Geoportal Extension, ArcGIS Image Server and Tracking Server as well as several others. Mobile GIS conflates GIS, GPS, location-based services, hand-held computing, the growing availability of geographic data. ArcGIS technology can be deployed on a range of mobile systems from lightweight devices to PDAs, Tablet PCs; the firm's products for this use are ArcPad, ArcGIS for Mobile, ArcGIS for Server, ArcWeb Services, hosted geographic databases, ArcGIS mobile. ArcGIS for mobile ADF is an application programming interface for developing solutions on various Windows Mobile and Windows-embedded platforms. Developer GIS products enable building custom desktop or server GIS appli