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 digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, moon, or asteroid. A "global DEM" refers to a discrete global grid. DEMs are used often in geographic information systems (GIS), and are the most common basis for digitally produced relief maps. A digital terrain model (DTM) represents specifically the ground surface while DEM and DSM may represent tree top canopy or building roofs.
The Blue Marble is a photograph of Earth taken on December 7, 1972, from a distance of around 29,000 kilometers from the planet's surface. Taken by the crew of the Apollo 17 spacecraft on its way to the Moon, it is one of the most reproduced images in history.
Landsat 7 is the seventh satellite of the Landsat program. Launched on 15 April 1999, Landsat 7's primary goal is to refresh the global archive of satellite photos, providing up-to-date and cloud-free images. The Landsat program is managed and operated by the United States Geological Survey, and data from Landsat 7 is collected and distributed by the USGS. The NASA WorldWind project allows 3D images from Landsat 7 and other sources to be freely navigated and viewed from any angle. The satellite's companion, Earth Observing-1, trailed by one minute and followed the same orbital characteristics, but in 2011 its fuel was depleted and EO-1's orbit began to degrade. Landsat 7 was built by Lockheed Martin Space Systems.
GeoTIFF is a public domain metadata standard which allows georeferencing information to be embedded within a TIFF file. The potential additional information includes map projection, coordinate systems, ellipsoids, datums, and everything else necessary to establish the exact spatial reference for the file. The GeoTIFF format is fully compliant with TIFF 6.0, so software incapable of reading and interpreting the specialized metadata will still be able to open a GeoTIFF format file.
NASA WorldWind is an open-source virtual globe. According to the website, "WorldWind is an open source virtual globe API. WorldWind allows developers to quickly and easily create interactive visualizations of 3D globe, map and geographical information. Organizations around the world use WorldWind to monitor weather patterns, visualize cities and terrain, track vehicle movement, analyze geospatial data and educate humanity about the Earth." It was first developed by NASA in 2003 for use on personal computers and then further developed in concert with the open source community since 2004. As of 2017, a web-based version of WorldWind is available online. An Android version is also available.
Satellite images are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell images by licensing them to governments and businesses such as Apple Maps and Google Maps.
Google Earth is a computer program that renders a 3D representation of Earth based primarily on satellite imagery. The program maps the Earth by superimposing satellite images, aerial photography, and GIS data onto a 3D globe, allowing users to see cities and landscapes from various angles. Users can explore the globe by entering addresses and coordinates, or by using a keyboard or mouse. The program can also be downloaded on a smartphone or tablet, using a touch screen or stylus to navigate. Users may use the program to add their own data using Keyhole Markup Language and upload them through various sources, such as forums or blogs. Google Earth is able to show various kinds of images overlaid on the surface of the earth and is also a Web Map Service client. In 2019, Google has revealed that Google Earth now covers more than 97 percent of the world, and has captured 10 million miles of Street View imagery.
Earth Satellite Corporation (EarthSat), an American company, was a pioneer in the commercial use of Earth observation satellites. Founded in 1969, EarthSat was first headquartered in Washington, D.C., and later moved its offices to Bethesda, Maryland, and finally to Rockville, Maryland, in the late 1980s. In 2001, EarthSat was acquired by MacDonald, Dettwiler and Associates Ltd. (MDA) of Vancouver, British Columbia. In August 2005, EarthSat was incorporated as MDA Federal Inc., the U.S. operation of MDA Geospatial Services.
OpenStreetMap (OSM) is a free, open geographic database updated and maintained by a community of volunteers via open collaboration. Contributors collect data from surveys, trace from aerial imagery and also import from other freely licensed geodata sources. OpenStreetMap is freely licensed under the Open Database License and as a result commonly used to make electronic maps, inform turn-by-turn navigation, assist in humanitarian aid and data visualisation. OpenStreetMap uses its own topology to store geographical features which can then be exported into other GIS file formats. The OpenStreetMap website itself is an online map, geodata search engine and editor.
The Open Source Geospatial Foundation (OSGeo), is a non-profit non-governmental organization whose mission is to support and promote the collaborative development of open geospatial technologies and data. The foundation was formed in February 2006 to provide financial, organizational and legal support to the broader Free and open-source geospatial community. It also serves as an independent legal entity to which community members can contribute code, funding and other resources.
The Geospatial Data Abstraction Library (GDAL) is a computer software library for reading and writing raster and vector geospatial data formats, and is released under the permissive X/MIT style free software license by the Open Source Geospatial Foundation. As a library, it presents a single abstract data model to the calling application for all supported formats. It may also be built with a variety of useful command line interface utilities for data translation and processing. Projections and transformations are supported by the PROJ library.
JTS Topology Suite is an open-source Java software library that provides an object model for Euclidean planar linear geometry together with a set of fundamental geometric functions. JTS is primarily intended to be used as a core component of vector-based geomatics software such as geographical information systems. It can also be used as a general-purpose library providing algorithms in computational geometry.
Digital Earth is the name given to a concept by former US vice president Al Gore in 1998, describing a virtual representation of the Earth that is georeferenced and connected to the world's digital knowledge archives.
Web mapping or an online mapping is the process of using maps, usually created through geographic information systems (GIS) on the Internet, more specifically in the World Wide Web. A web map or an online map is both served and consumed, thus, web mapping is more than just web cartography, it is a service where consumers may choose what the map will show.
Bhuvan is an Indian web based utility which allows users to explore a set of map based content prepared by Indian Space Research Organisation. The content which the utility serves is mostly restricted to Indian boundaries and is offered in 4 regional languages. The content includes thematic maps related to disasters, agriculture, water resources, land cover and also processed satellite data of ISRO. Bhuvan is known for its association with various sections of Government of India to enable the use of Geospatial technology. Bhuvan has since its inception enabled Indian government to host public geospatial data as Information layers for visualisation and public consumption. Examples of the types of geospatial layers include Toll Information System for National Highways Authority of India, Islands information System for MHA, Cultural heritage sites for Ministry of culture etc. The information for the platform is obtained from the government of India sources or through Crowdsourcing.
Earth3D was developed as part of a diploma thesis of Dominique Andre Gunia at Braunschweig University of Technology to display a virtual globe of the earth. It was developed before Google bought Keyhole, Inc and changed their product into Google Earth. Earth3D downloads its data from a server while the user navigates around. The data itself is saved in a Quadtree. It uses data from NASA, USGS, the CIA and the city of Osnabrück.
The Geoscope was a proposal by Buckminster Fuller around 1960 to create a 200-foot-diameter (61 m) globe that would be covered in colored lights so that it could function as a large spherical display. It was envisioned that the Geoscope would be connected to computers which would allow it to display both historical and current data, and enable people to visualize large scale patterns around the world. Several projects by his students to build a "miniature Earth", starting with a 20-foot version at Cornell University in 1952, were precursors of the Geoscope proposal. Before proposing the Geoscope, Fuller had invented the Dymaxion map, a novel map projection for the whole Earth.
Bing Maps Platform is a geospatial mapping platform produced by Microsoft. It allows developers to create applications that layer location-relevant data on top of licensed map imagery. The imagery includes samples taken by satellite sensors, aerial cameras, Streetside imagery, 3D city models and terrain.
In science, the concept of a macroscope is the antithesis of the microscope, namely a method, technique or system appropriate to the study of very large objects or very complex processes, for example the Earth and its contents, or conceptually, the Universe. Obviously, a single system or instrument does not presently exist that could fulfil this function, however its concept may be approached by some current or future combination of existing observational systems. The term "macroscope" has also been applied to a method or compendium which can view some more specific aspect of global scientific phenomena in its entirety, such as all plant life, specific ecological processes, or all life on earth. The term has also been used in the humanities, as a generic label for tools which permit an overview of various other forms of "big data". As discussed here, the concept of a "macroscope" differs in essence from that of the macroscopic scale, which simply takes over from where the microscopic scale leaves off, covering all objects large enough to be visible to the unaided eye, as well as from macro photography, which is the imaging of specimens at magnifications greater than their original size, and for which a specialised microscope-related instrument known as a "Macroscope" has previously been marketed. For some workers, one or more "macroscopes" can already be constructed, to access the sum of relevant existing observations, while for others, deficiencies in current sampling regimes and/or data availability point to additional sampling effort and deployment of new methodologies being required before a true "macroscope" view of Earth can be obtained.
