Roger Tomlinson coined GIS in the mid-1960s
A geographic information system stores, analyzes, and maps layers of location-tagged data on computers. Location becomes the index that relates otherwise separate tables. Roger Tomlinson named the idea in the mid-1960s, though older geographic methods fed the software era.
The core trick of a GIS is to use place as a shared key. Anything recorded with a time and with x, y and z coordinates, meaning longitude, latitude and elevation, can be joined to anything else recorded the same way, however unrelated the original datasets. That is why the technology underpins engineering, logistics, insurance, telecoms, forestry, ecology and the location services on phones. The word also names the profession, while the academic field is usually called GIScience, a branch of technical geography.
Mapping data to find patterns is older than computers. An 1832 report on cholera in Paris used Charles Picquet's shaded map of the city's forty-eight districts to show deaths per thousand residents. In 1854 John Snow plotted London cholera victims and nearby water pumps, and the cluster pointed to the contaminated source. Early 20th-century photozincography let mapmakers split maps into separate layers for water, vegetation or contours, an idea later formalised in Ian McHarg's overlay method.
Waldo Tobler published the first account of computer-aided cartography in 1959. In 1963 Canada's Department of Forestry and Rural Development in Ottawa built the first working GIS, Roger Tomlinson's Canada Geographic Information System, to assess rural land for the Canada Land Inventory. It could store, overlay, measure and scan data on a continent-wide coordinate system, earning Tomlinson the title father of GIS. Howard Fisher's Harvard laboratory, founded in 1964, spread programs such as SYMAP and ODYSSEY, and Tom Waugh's GIMMS, sold from Edinburgh from 1973, ran at 300 sites by 1977.
Commercial vendors including ESRI and Intergraph appeared by the early 1980s alongside public-domain systems such as GRASS. MIDAS, the first desktop GIS, arrived for MS-DOS in 1986 and became MapInfo for Windows in 1990, carrying the tools from research labs into business. Since the late 1990s GIS has moved onto servers, into spatial database extensions and into open-source packages and programming libraries.
Source: Geographic information system
