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This is a list of GIS data sources (including some geoportals) that provide information sets that can be used in geographic information systems (GIS) and spatial databases for purposes of geospatial analysis and cartographic mapping. This list categorizes the sources of interest.
GIS data acquisition includes several methods for gathering spatial data into a GIS database, which can be grouped into three categories: primary data capture, the direct measurement phenomena in the field (e.g., remote sensing, the global positioning system); secondary data capture, the extraction of information from existing sources that are ...
The origin of the geodatabase was in the mid-1990s during the emergence of the first spatial databases.One early approach to integrating relational databases and GIS was the use of server middleware, a third-party program that stores the spatial data in database tables in a custom format, and translates it dynamically into a logical model that can be understood by the client software.
There are also many different types of geodata, including vector files, raster files, geographic databases, web files, and multi-temporal data. Spatial data or spatial information is broader class of data whose geometry is relevant but it is not necessarily georeferenced , such as in computer-aided design (CAD), see geometric modeling .
The georelational data model was the basis for most early vector GIS software. [19] The geometric data and the attribute data are stored separately; this was originally because the geometric data required GIS-specific code to process it, but existing relational database software (RDBMS) could be
The Open Geospatial Consortium (OGC) is an international voluntary consensus standards organization that develops and maintains international standards for geospatial content and location-based services, sensor web, Internet of Things, GIS data processing and data sharing. The OGC was incorporated as a not for profit in 1994.
The World Wide Web is an information system that uses the internet to host, share, and distribute documents, images, and other data. [33] 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. [7]
The scale of the Web can sometimes make finding quality and reliable data a challenge for GIS professionals and end users, with a significant amount of low-quality, poorly organized, or poorly sourced material available for public consumption. [13] [14] This can make finding spatial data a time consuming activity for GIS users. [13]