Difference between revisions of "Time In GIS"
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This page of the OSGeo Wiki contains some tidbits of information about represting time or working with time in geographic information systems. (This is also known as temporal GIS.) This is not a comprehensive coverage of the topic. It is a collection and summary of responses to a question about temporal GIS that I posted to the OSGeo Discussion Mailing List and Geowanking Mailing List. | This page of the OSGeo Wiki contains some tidbits of information about represting time or working with time in geographic information systems. (This is also known as temporal GIS.) This is not a comprehensive coverage of the topic. It is a collection and summary of responses to a question about temporal GIS that I posted to the OSGeo Discussion Mailing List and Geowanking Mailing List. | ||
− | The Sunburned Surveyor | + | '''The Sunburned Surveyor''' |
− | + | ||
+ | ==Using Linear Referencing To Work With Time In GIS== | ||
You can use built-in linear referencing functionality in geographic information systems or relational databases as a "hack" to work with time. A line or other linear geometry is used to represent a "timeline". | You can use built-in linear referencing functionality in geographic information systems or relational databases as a "hack" to work with time. A line or other linear geometry is used to represent a "timeline". | ||
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http://grass.osgeo.org/grass63/manuals/html63_user/vectorintro.html | http://grass.osgeo.org/grass63/manuals/html63_user/vectorintro.html | ||
− | + | ==More Than Just Events== | |
Working with time in GIS can involve more than just the concept of an "event" or a single instant in time. It can also involve a chain of events or "history" of an object or feature modeled in a GIS. (For example, a survey monument can be "Set", "Recovered", "Disturbed", and "Destroyed". These are all events. A single survey monument could "own" all of these events, which would form its history.) | Working with time in GIS can involve more than just the concept of an "event" or a single instant in time. It can also involve a chain of events or "history" of an object or feature modeled in a GIS. (For example, a survey monument can be "Set", "Recovered", "Disturbed", and "Destroyed". These are all events. A single survey monument could "own" all of these events, which would form its history.) | ||
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http://www.port.ac.uk/research/gbhgis/aboutthegbhistoricalgis/database/ | http://www.port.ac.uk/research/gbhgis/aboutthegbhistoricalgis/database/ | ||
− | Additional Material | + | ==Additional Material== |
ISO 19108 - Temporal Schema | ISO 19108 - Temporal Schema | ||
[http://www.amazon.com/Geographic-Information-Systems-Stone-Light/dp/0748400036 Time in Geographic Information Systems (Book Authored By Langran and Gail in 1992)] | [http://www.amazon.com/Geographic-Information-Systems-Stone-Light/dp/0748400036 Time in Geographic Information Systems (Book Authored By Langran and Gail in 1992)] | ||
− | Links | + | ==Links== |
[http://www.slideshare.net/mikel_maron/its-about-time-for-time Talk On Time In GIS At FOSS4G In 2006] | [http://www.slideshare.net/mikel_maron/its-about-time-for-time Talk On Time In GIS At FOSS4G In 2006] | ||
[http://joda-time.sourceforge.net/ Joda (Java Time Programming Library)] | [http://joda-time.sourceforge.net/ Joda (Java Time Programming Library)] |
Revision as of 09:24, 21 December 2007
This page of the OSGeo Wiki contains some tidbits of information about represting time or working with time in geographic information systems. (This is also known as temporal GIS.) This is not a comprehensive coverage of the topic. It is a collection and summary of responses to a question about temporal GIS that I posted to the OSGeo Discussion Mailing List and Geowanking Mailing List.
The Sunburned Surveyor
Using Linear Referencing To Work With Time In GIS
You can use built-in linear referencing functionality in geographic information systems or relational databases as a "hack" to work with time. A line or other linear geometry is used to represent a "timeline".
Doctor Shih-Lung Shaw (University of Tennessee) and Doctor Hongbo Yu (Oklahoma State) have done some interesting work that use this method to work with events in temporal gis.
PostGIS and GRASS contain this linear referencing functionality: http://postgis.refractions.net/docs/ch06.html#id3060376 http://grass.osgeo.org/grass63/manuals/html63_user/vectorintro.html
More Than Just Events
Working with time in GIS can involve more than just the concept of an "event" or a single instant in time. It can also involve a chain of events or "history" of an object or feature modeled in a GIS. (For example, a survey monument can be "Set", "Recovered", "Disturbed", and "Destroyed". These are all events. A single survey monument could "own" all of these events, which would form its history.)
Working with time in GIS can also allow us to understand the evolution of objects for features modeled in a GIS. (For example, a railroad can become a pedestrian trail.) This deals with the lineage or heritage of an object or feature. It stores information about what a feature was created from and what it eventually became or evolved into.
This issue was dealt with on the Great Britain Historical GIS:
www.visionofbritain.org.uk http://www.port.ac.uk/research/gbhgis/aboutthegbhistoricalgis/database/
Additional Material
ISO 19108 - Temporal Schema Time in Geographic Information Systems (Book Authored By Langran and Gail in 1992)
Links
Talk On Time In GIS At FOSS4G In 2006 Joda (Java Time Programming Library)