Places are a recurring theme in the SemanticWeb, along with people, documents, times, and money. (see FriendOfaFriend, DublinCore, RdfCalendar, as well as SeedApplications and VocabularyMarket). See GeoOnion for an attempt to relate lat/long points to 'within n metres of' concentric circles that encompass them.
So far, we have a lat/long vocab page and workspace. The coolest thing about it is probably that the GeoURL database, with zillions of web pages related to lat/long, can be queried with results in RDF using this vocabulary; results look like...
<rdf:RDF xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"> <rdf:Description rdf:about="http://www.cs.cmu.edu/~sprite/index.html"> <dc:title>Bridget Spitznagel</dc:title> <foaf:topic rdf:parseType="Resource"> <geo:lat>40.442673</geo:lat> <geo:long>-79.945815</geo:long> </foaf:topic> </rdf:Description> </rdf:RDF>
Q & A
Is there an upcoming ScheduledTopicChat on this stuff?
- hmm... not clear.
- stay tuned to www-rdf-interest MailingLists for notice, which should come a week or so in advance.
What's on the agenda?
- review of outstanding stuff from 16Apr, 30 Apr, 28 May:
- ActionItems on libby, danbri, danc, @@others?
- your agenda request here
Has there been any ScheduledTopicChat on this stuff?
- 28 May weblog: GML, shapefiles, geotools, timezone shapefiles
- 30 Apr weblog
- notes from 16Apr, 16 Apr geo meeting calendar
- 9Apr summary
Who's working on this stuff?
The following folks have shown interest:
- DanBri (prefers weds for #rdfig chats)
See also attendance records for previous chats, above.
Is this a formal standardization effort?
- It is more of an experiment in representing mapping and location data within the RDF graph data model.
Is anybody building an RDF vocabulary for stuff like latitude/longitude?
- the lat/long vocab page and workspace is nearby. It's based on WGS 84 - World Geodetic System 1984. See also the Background document
- Earth Maps, Latitudes, and Longitudes: An RDF Schema (in RDF/N3, based on Xplanet) (is it WGS84? can we define sub-properties?)
- RDFMap spec (rss-dev announcment and follow up).
- DAML GEO stuff: daml-spatial list archive
- SUMO; e.g. spatial ontology starter Adam Pease 27 Jan 2003 to daml-spatial
- the cyc geography vocabulary was released in DAML/RDF/XML form: cyc.daml. @@when? there's a newer release, too, isn't there?
- Geonames.org Ontology
Need to be careful about specifity
OK, but you can't put RDF into XHTML and have it (easily) validate. So what's the best way to get georeferencing data into an (X)HTML page? There seem to be many choices, without a clear winner. The DublinCore DC.Coverage.spatial type would seem to be the most desireable, but is perhaps the one that is least defined (at least it is confusing to implement)
(X)HTML georeferencing formats:
RSS georeferencing formats:
RSS Reader using GeoInfo:
- [www.plazoo.com/info/de/newsreader.asp RSS Reader from plazoo]
Other georeferencing formats:
-  and Open GIS standards OpenGIS-Specs Check out GML.
- ANZLIC (Australian)
Further reading on georeferencing metadata
Is anybody using this wgs_84 vocab? Are there collaborative RDF knowledgebases about geo info I can contribute to?
- GeoURL maps lat/long to web pages and their dc:title, plus the geo:lat/geo:long of a related foaf:topic. e.g. weather at G7WBE see also info on locating and adding yourself (does this use wgs_84? or somethign else?)
- spacenamespace (sample record for Bethnal_Green_Station, now using our wgs_84 vocab)
How accurate are lat/lon coordinates? Georeferencing Guidelines contains a lot of useful background information on georeferencing, but most importantly, contains a table that details the level of uncertainty (in meters) associated with various levels of precision in WGS-84 coordinates.
what do you mean by WGS_84 vocab?
So why doesn't the WGS-84 vocab explicitly reference wgs-84 in the resulting RDF data? Not having the string WGS-84 near the lat/lon coordinates may make it unclear to software which coordinate system is referenced. Especially since the schema states A point, typically described using a coordinate system relative to Earth, such as WGS84.?
Business cards have geographical info; anybody playing with that?
- see GeoVcard
Travel planning is a pain; does the SemanticWeb help?
- see TravelTools
Speaking of travel... can I use the SemanticWeb to find restaurants when I travel?
What if I want to blog about the places I visit?
Any other RDF data about places?
- DAML Geofile Descriptions
- Address location data for Denmarks 2.2 million official addresses - Coordinates are in "EUREF 89 (WGS84) UTM zone 32". Also available in RDF/XML from the Danish node of the spacenamespace project.
- GovTrack's usgeo.uf1.towns.n3 and usgeo.uf1.villages.n3 contain lat/long coords of all towns and census-places in the U.S., using wgs_84.
does anyone have some pointers for storing TGN-like geographic place information in RDF? specifically, place containership i.e. a place called england contains a place called sussex?
- The TAP KB does; e.g. CountryUnited_Kingdom
OK, so lat/long seems done; what about relations between places... inRegion, cospatial and the like?
An intern at W3C is going to work on an SVG tool for putting things on maps and being able to use different kinds of description - lat/long, named places, etc. He starts on 2003-05-05. The 4 month project is not yet completely defined, and suggestions (via mailing list) are welcome.
Are there any cool SVG visualization tools?
How can I map city names to latitude/longitude?
- see CityLookup, a use case for mapping weather underground data to lat/long with cwm
- GeoURL's resources page has lots of useful links for finding lat/long from maps
How can I compute distances between places?
- RDF And Distances, by Sean Palmer. Uses Cwm to generate a set of distances from town to town in the U.S.A., based upon map coordinates. (also schema: infomesh-geo)
Any work on U.S. Postal info, like city/state/zip? Can I print mailing labels from RDF data?
- An RDF Schema for United States Postal Addressing Standards by DanConnolly (in RDF/N3)
- jobieLabels.pl in swap pim works in limited cases (specific RDF schema, printer, avery label size); though it's written in perl and you could adapt it to your situation.
Are there sources of data out there that I might mine for geographic data?
- US Zip Codes
- UK waypoints (over 5000 waypoints for download)
- Free Geo Data
- UK waypoints (over 5000 waypoints for download)
- waypoints (over 8000 waypoints for download)
- The Ordnance Survey of Britain and Conversion of Latitude and Longitude to/from OS references FAQ notes by Phil Brady (includes information on conversion code, including MS Excel .xls and Quickbasic versions)
- NGA's GEOnet Names Server seems to be the source for the U.N.'s
How about existing open source software I can build on?