Editing Geographic information system (section)

==Other aspects==
===Open Geospatial Consortium standards===
{{Main|Open Geospatial Consortium}}
The [[Open Geospatial Consortium]] (OGC) is an international industry consortium of 384&nbsp;companies, government agencies, universities, and individuals participating in a consensus process to develop publicly available geoprocessing specifications. Open interfaces and protocols defined by OpenGIS&nbsp;Specifications support interoperable solutions that "geo-enable" the Web, wireless and location-based services, and mainstream&nbsp;IT, and empower technology developers to make complex spatial information and services accessible and useful with all kinds of applications. Open Geospatial Consortium protocols include [[Web Map Service]], and [[Web Feature Service]].<ref>{{cite web|url=http://www.opengeospatial.org/ogc/members |title=OGC Members &#124; OGC(R) |publisher=Opengeospatial.org |access-date=13 May 2012}}</ref>

GIS&nbsp;products are broken down by the&nbsp;OGC into two categories, based on how completely and accurately the software follows the OGC&nbsp;specifications.
[[File:Geoservices server with apps.png|thumb|347px|OGC standards help GIS tools communicate.]]

''Compliant products'' are software products that comply to OGC's&nbsp;OpenGIS&nbsp;Specifications. When a product has been tested and certified as compliant through the OGC&nbsp;Testing Program, the product is automatically registered as "compliant" on this site.

''Implementing products'' are software products that implement OpenGIS&nbsp;Specifications but have not yet passed a compliance test. Compliance tests are not available for all specifications. Developers can register their products as implementing draft or approved specifications, though OGC&nbsp;reserves the right to review and verify each entry.

===Adding the dimension of time===
<!--This section is linked from [[Historical geographic information system]] and [[Time geography]] ([[MOS:HEAD]])-->
{{See also|Historical geographic information system|Time geography}}
The condition of the Earth's surface, atmosphere, and subsurface can be examined by feeding satellite data into a GIS. GIS&nbsp;technology gives researchers the ability to examine the variations in Earth processes over days, months, and years through the use of cartographic visualizations.<ref>{{cite journal |last1=Monmonier |first1=Mark |title=Strategies For The Visualization Of Geographic Time-Series Data |journal=Cartographica: The International Journal for Geographic Information and Geovisualization |date=1990 |volume=27 |issue=1 |pages=30–45 |doi=10.3138/U558-H737-6577-8U31}}</ref> As an example, the changes in vegetation vigor through a growing season can be animated to determine when drought was most extensive in a particular region. The resulting graphic represents a rough measure of plant health. Working with two variables over time would then allow researchers to detect regional differences in the lag between a decline in rainfall and its effect on vegetation.

GIS&nbsp;technology and the availability of digital data on regional and global scales enable such analyses. The satellite sensor output used to generate a vegetation graphic is produced for example by the [[advanced very-high-resolution radiometer]] (AVHRR). This sensor system detects the amounts of energy reflected from the Earth's surface across various bands of the spectrum for surface areas of about {{Convert|1|km2|sqmi|abbr=on}}. The satellite sensor produces images of a particular location on the Earth twice a day. AVHRR and more recently the [[moderate-resolution imaging spectroradiometer]] (MODIS) are only two of many sensor systems used for Earth surface analysis.

In addition to the integration of time in environmental studies, GIS is also being explored for its ability to track and model the progress of humans throughout their daily routines. A concrete example of progress in this area is the recent release of time-specific population data by the [[U.S.&nbsp;Census]]. In this data set, the populations of cities are shown for daytime and evening hours highlighting the pattern of concentration and dispersion generated by North American commuting patterns. The manipulation and generation of data required to produce this data would not have been possible without&nbsp;GIS.

Using models to project the data held by a GIS&nbsp;forward in time have enabled planners to test policy decisions using [[spatial decision support system]]s.

===Semantics===
Tools and technologies emerging from the [[World Wide Web Consortium]]'s [[Semantic Web]] are proving useful for [[data integration]] problems in information systems. Correspondingly, such technologies have been proposed as a means to facilitate [[interoperability]] and data reuse among GIS&nbsp;applications and also to enable new analysis mechanisms.<ref>{{cite book |last1=Zhang |first1=Chuanrong |last2=Zhao |first2=Tian |last3=Li |first3=Weidong |title=Geospatial Semantic Web |date=2015 |publisher=Springer International Publishing |isbn=978-3-319-17801-1}}</ref><ref>{{Cite journal |last1=Fonseca |first1=Frederico | last2 = Sheth | first2 = Amit |journal=UCGIS White Paper | title= The Geospatial Semantic Web |year=2002 |url = http://www.personal.psu.edu/faculty/f/u/fuf1/Fonseca-Sheth.pdf }}</ref><ref>{{Cite journal |last1=Fonseca |first1=Frederico | last2 = Egenhofer | first2 = Max |journal=Proc. ACM International Symposium on Geographic Information Systems |title= Ontology-Driven Geographic Information Systems |year=1999 |pages=14–19 |citeseerx=10.1.1.99.5206 }}</ref><ref>{{Cite journal | last1 = Perry | first1 = Matthew | last2 = Hakimpour | first2 = Farshad | last3 = Sheth | first3 = Amit | journal = Proc. ACM International Symposium on Geographic Information Systems | title = Analyzing Theme, Space and Time: an Ontology-based Approach | url = http://knoesis.wright.edu/library/download/ACM-GIS_06_Perry.pdf | year = 2006 | pages = 147–154 | access-date = 2007-05-29 | archive-date = 2007-06-14 | archive-url = https://web.archive.org/web/20070614120623/http://knoesis.wright.edu/library/download/ACM-GIS_06_Perry.pdf | url-status = dead }}</ref>

[[Ontology (computer science)|Ontologies]] are a key component of this semantic approach as they allow a formal, machine-readable specification of the concepts and relationships in a given domain. This in turn allows a GIS to focus on the intended meaning of data rather than its syntax or structure. For example, [[reasoning]] that a land cover type classified as ''deciduous needleleaf trees'' in one dataset is a specialization or subset of land cover type ''forest'' in another more roughly classified dataset can help a GIS automatically merge the two datasets under the more general land cover classification. Tentative ontologies have been developed in areas related to GIS&nbsp;applications, for example the hydrology ontology<ref>{{cite web|url=http://www.ordnancesurvey.co.uk/oswebsite/ontology/|title=Ordnance Survey Ontologies |archive-url=https://web.archive.org/web/20070521025424/http://www.ordnancesurvey.co.uk/oswebsite/ontology/|archive-date=21 May 2007}}</ref> developed by the [[Ordnance Survey]] in the [[United Kingdom]] and the SWEET ontologies<ref>{{cite web |url=http://sweet.jpl.nasa.gov/ontology/ |title=Semantic Web for Earth and Environmental Terminology |url-status=dead |archive-url=https://web.archive.org/web/20070529200940/http://sweet.jpl.nasa.gov/ontology/ |archive-date=29 May 2007 }}</ref> developed by [[NASA]]'s [[Jet Propulsion Laboratory]]. Also, simpler ontologies and semantic metadata standards are being proposed by the W3C Geo Incubator Group<ref>{{cite web|url= http://www.w3.org/2005/Incubator/geo/|title= W3C Geospatial Incubator Group}}</ref> to represent geospatial data on the web. [[GeoSPARQL]] is a standard developed by the Ordnance Survey, [[United States Geological Survey]], [[Natural Resources Canada]], Australia's [[Commonwealth Scientific and Industrial Research Organisation]] and others to support ontology creation and reasoning using well-understood OGC literals (GML, WKT), topological relationships (Simple Features, RCC8, DE-9IM), RDF and the [[SPARQL]] database query protocols.

Recent research results in this area can be seen in the International Conference on Geospatial Semantics<ref>{{cite web|url= http://www.geosco.org/|title= International Conferences on Geospatial Semantics}}</ref> and the Terra Cognita – Directions to the Geospatial Semantic Web<ref>{{cite web|url=http://www.ordnancesurvey.co.uk/oswebsite/partnerships/research/research/terracognita.html|title=Terra Cognita 2006 – Directions to the Geospatial Semantic Web |archive-url=https://web.archive.org/web/20070518054232/http://www.ordnancesurvey.co.uk/oswebsite/partnerships/research/research/terracognita.html|archive-date=18 May 2007}}</ref> workshop at the International Semantic Web Conference.