Related Research Articles
A geographic information system (GIS) consists of integrated computer hardware and software that store, manage, analyze, edit, output, and visualize geographic data. Much of this often happens within a spatial database, however, this is not essential to meet the definition of a GIS. In a broader sense, one may consider such a system also to include human users and support staff, procedures and workflows, the body of knowledge of relevant concepts and methods, and institutional organizations.
A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes.
In modern mapping, a topographic map or topographic sheet is a type of map characterized by large-scale detail and quantitative representation of relief features, usually using contour lines, but historically using a variety of methods. Traditional definitions require a topographic map to show both natural and artificial features. A topographic survey is typically based upon a systematic observation and published as a map series, made up of two or more map sheets that combine to form the whole map. A topographic map series uses a common specification that includes the range of cartographic symbols employed, as well as a standard geodetic framework that defines the map projection, coordinate system, ellipsoid and geodetic datum. Official topographic maps also adopt a national grid referencing system.
Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps.
The Geography Markup Language (GML) is the XML grammar defined by the Open Geospatial Consortium (OGC) to express geographical features. GML serves as a modeling language for geographic systems as well as an open interchange format for geographic transactions on the Internet. Key to GML's utility is its ability to integrate all forms of geographic information, including not only conventional "vector" or discrete objects, but coverages and sensor data.
A coverage is the digital representation of some spatio-temporal phenomenon. ISO 19123 provides the definition:
A projected coordinate system – also called a projected coordinate reference system, planar coordinate system, or grid reference system – is a type of spatial reference system that represents locations on Earth using Cartesian coordinates (x, y) on a planar surface created by a particular map projection. Each projected coordinate system, such as "Universal Transverse Mercator WGS 84 Zone 26N," is defined by a choice of map projection (with specific parameters), a choice of geodetic datum to bind the coordinate system to real locations on the earth, an origin point, and a choice of unit of measure. Hundreds of projected coordinate systems have been specified for various purposes in various regions.
The Geographic Names Information System (GNIS) is a database of name and location information about more than two million physical and cultural features throughout the United States and its territories; the associated states of the Marshall Islands, Federated States of Micronesia, and Palau; and Antarctica. It is a type of gazetteer. It was developed by the United States Geological Survey (USGS) in cooperation with the United States Board on Geographic Names (BGN) to promote the standardization of feature names.
The OS MasterMap is the premier digital product of the Ordnance Survey. It was launched in November 2001. It is a database that records every fixed feature of Great Britain larger than a few meters in one continuous digital map. Every feature is given a unique TOID, a simple identifier that includes no semantic information. Typically each TOID is associated with a polygon that represents the area on the ground that the feature covers, in National Grid coordinates. OS MasterMap is offered in themed "layers", for example a road layer and a building layer, each linked to a number of TOIDs. Pricing of licenses for OS MasterMap data depends on: the total area requested, the layers licensed, the number of TOIDs in the layers, the period in years of the data usage.
A spatial reference system (SRS) or coordinate reference system (CRS) is a framework used to precisely measure locations on the surface of Earth as coordinates. It is thus the application of the abstract mathematics of coordinate systems and analytic geometry to geographic space. A particular SRS specification comprises a choice of Earth ellipsoid, horizontal datum, map projection, origin point, and unit of measure. Thousands of coordinate systems have been specified for use around the world or in specific regions and for various purposes, necessitating transformations between different SRS.
Address Point is a mapping/GIS data product supplied by Great Britain's national mapping agency, Ordnance Survey. It is based on the UK’s postal mail organisation, the Royal Mail, list of postal addresses, Postcode Address File (PAF). The most significant difference between Royal Mail list and Address Point is that Address Point includes the geographic coordinates of each postal address. This enables users to map the individual addresses.
A feature, in the context of geography and geographic information science, is something that exists at a moderate to scale at a location in the space and scale of relevance to geography; that is, at or near the surface of Earth. It is an item of geographic information, and may be represented in maps, geographic information systems, remote sensing imagery, statistics, and other forms of geographic discourse. Such representations of features consist of descriptions of their inherent nature, their spatial form and location, and their characteristics or properties.
A 3D city model is digital model of urban areas that represent terrain surfaces, sites, buildings, vegetation, infrastructure and landscape elements in three-dimensional scale as well as related objects belonging to urban areas. Their components are described and represented by corresponding two- and three-dimensional spatial data and geo-referenced data. 3D city models support presentation, exploration, analysis, and management tasks in a large number of different application domains. In particular, 3D city models allow "for visually integrating heterogeneous geoinformation within a single framework and, therefore, create and manage complex urban information spaces."
A geographic data model, geospatial data model, or simply data model in the context of geographic information systems, is a mathematical and digital structure for representing phenomena over the Earth. Generally, such data models represent various aspects of these phenomena by means of geographic data, including spatial locations, attributes, change over time, and identity. For example, the vector data model represents geography as collections of points, lines, and polygons, and the raster data model represent geography as cell matrices that store numeric values. Data models are implemented throughout the GIS ecosystem, including the software tools for data management and spatial analysis, data stored in a variety of GIS file formats, specifications and standards, and specific designs for GIS installations.
Cartographic generalization, or map generalization, includes all changes in a map that are made when one derives a smaller-scale map from a larger-scale map or map data. It is a core part of cartographic design. Whether done manually by a cartographer or by a computer or set of algorithms, generalization seeks to abstract spatial information at a high level of detail to information that can be rendered on a map at a lower level of detail.
The Ordnance Survey (OS) is the national mapping agency for Great Britain. The agency's name indicates its original military purpose, which was to map Scotland in the wake of the Jacobite rising of 1745. There was also a more general and nationwide need in light of the potential threat of invasion during the Napoleonic Wars. Since 1 April 2015, the Ordnance Survey has operated as Ordnance Survey Ltd, a government-owned company, 100% in public ownership. The Ordnance Survey Board remains accountable to the Secretary of State for Science, Innovation and Technology. It was also a member of the Public Data Group.
A national mapping agency (NMA) is an organisation, usually publicly owned, that produces topographic maps and geographic information of a country. Some national mapping agencies also deal with cadastral matters.
Spatial contextual awareness consociates contextual information such as an individual's or sensor's location, activity, the time of day, and proximity to other people or objects and devices. It is also defined as the relationship between and synthesis of information garnered from the spatial environment, a cognitive agent, and a cartographic map. The spatial environment is the physical space in which the orientation or wayfinding task is to be conducted; the cognitive agent is the person or entity charged with completing a task; and the map is the representation of the environment which is used as a tool to complete the task.
A discrete global grid (DGG) is a mosaic that covers the entire Earth's surface. Mathematically it is a space partitioning: it consists of a set of non-empty regions that form a partition of the Earth's surface. In a usual grid-modeling strategy, to simplify position calculations, each region is represented by a point, abstracting the grid as a set of region-points. Each region or region-point in the grid is called a cell.
Web GIS, or Web Geographic Information Systems, are GIS that employ the World Wide Web to facilitate the storage, visualization, analysis, and distribution of spatial information over the Internet. The World Wide Web, or the Web, is an information system that uses the internet to host, share, and distribute documents, images, and other data. 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. While Web GIS and Internet GIS are sometimes used interchangeably, they are different concepts. Web GIS is a subset of Internet GIS, which is itself a subset of distributed GIS, which itself is a subset of broader Geographic information system. The most common application of Web GIS is Web mapping, so much so that the two terms are often used interchangeably in much the same way as Digital mapping and GIS. However, Web GIS and web mapping are distinct concepts, with web mapping not necessarily requiring a Web GIS.
References
- ↑ Brown, Paul (8 March 2004). "Devil is in the detail as OS maps out the future". Guardian. Retrieved 29 September 2021.
- ↑ "OS OpenData support". Ordnance Survey. Retrieved 29 September 2021.
- ↑ "Our policies". Ordnance Survey. Retrieved 29 September 2021.
- ↑ "Welcome to the Digital National Framework". Digital National Framework. Archived from the original on 29 December 2005. Retrieved 29 December 2005.