GIS, History of

Conceptual Landscape

The prowess of spatial analysis had been recognized for millennia in the use of maps to illustrate records, beginning with petroglyphs of optimal hunting areas and extending to Sumerian clay tablets for agricultural and land taxes. Mercator's map projections provided the first global standard for cartographic representations and hence can been viewed as one of the first “systems” for geographic information. Prior to the age of automation, examples of using overlay maps (i.e., space) to depict different object themes or time sequences for a geography were demonstrated in 1781 in the “Siege of Yorktown” sketches by Louis Alexandre Berthier (and the 1874 Louis van Blarenberghe painting based on the sketches) and in 1838 for the Atlas to Accompany the Second Report of the Irish Railway Commissioners. In 1912, the benefits of spatially overlaid maps were documented for both thematic maps of Billerica, Massachusetts, and time series maps of Düsseldorf, Germany. Spatial data overlay mapping methods were proving to be valuable analytic tools for large landscape projects. In 1969, Ian McHarg's seminal book Design With Nature formally introduced to a national audience of landscape architects and thoughtful managers the comprehensive power of systematic spatial analysis using transparent Mylar overlay maps for human development design and engineering. It remained for the influence of automated methods in the 1960s to establish the quantitative framework for the genesis of computer-based GIS.

Technology Prerequisites

Technology was a paramount factor in the creation of modern GIS, beginning with the confluence of Herman Hollerith's Census Bureau's data and command language punch cards operating on electronic computers from the postwar era of the late 1940s. Translating geographically referenced data, or geodata, into computers required many [Page 1282]inventions to facilitate this basic need. Geocoding techniques using Cartesian reference systems were required to keep links of data to geography. Database methods were created to capture the georeferenced files using various schemas. Manually typing in these records proved to be an onerous task, and capturing irregular grid-shaped features from maps necessitated scanners to digitize data, both from drum-based and from flatbed technologies, to create vector files. Visually displaying the results required the advent of cathode ray tubes (CRTs) to project maps and their layers. Collecting data for larger areas traditionally relied on aerial photographs (analog format) that were manually annotated and then digitally scanned (vector format). Digital remote sensing tools, beginning in the 1970s with the Landsat series of satellites, provided raster data format. Computer scientists created a variety of algorithms to frame the schema used to collect, store, and manipulate the digital data. Innovators designed and built automated systems to handle the challenges of acquiring spatial information and subsequently printing maps using the rapidly evolving computational tools of the space age. This progression followed the quantum leaps in computing power, beginning with large mainframe computers and leading up to laptops and field-portable, handheld display phones, enabling GIS mapping information to be transported anywhere on the globe.

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