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## Re: [ontolog-forum] GPS coordinates in an ontology?

 To: ontolog-forum@xxxxxxxxxxxxxxxx Steffen Lindek Wed, 27 Oct 2010 10:19:30 +0200 <4CC7E092.5070300@xxxxxxxxx>
 ```Doug and Sean,    (01) The reason for the variation of Berlin's position according to Sean's sources is not so much the extent of the urban area. It's rather due to a bad choice of coordinates by the NY Times. If you look up the position that it specifies, you end up near a small village north of Berlin.    (02) steffen    (03) On 27/10/2010 06:40, doug foxvog wrote: > On Tue, October 26, 2010 14:49, sean barker said: >> Just to add to the problem, it is interesting to compare the position of >> Berlin according to various sources: > Berlin is almost 900 sq. km. Giving its position to centi-microns, as > Geonames does makes no sense. If there is a an official marker from > which distances are measured, it makes some sense to give its location > to the closest meter. Specifying its center to the decimeter is not > very useful. > > An ontology for representing static places that extend in area needs more > than just to specify a single point. There are different ways to do this. > > Useful concepts to include in an ontology are > * defined reference location > * boundary curve(s) as one or more sets of vertexes with straight lines > (or arcs) connecting them > * bounding and bounded Mercator rectangle > * bounding/bounded circle > * Elevation > + average > + max& min > * Error bars for all locations (a useful concept for all measured values). > > Just like other measured values, the ontology should have multiple units > (and in this case systems of units) in which positions can be expressed. > Conversion tools or services should allow a value to be input/output > using any appropriate desired system. > > Moving objects would have a relation that specifies their 2D or 3D location > at given times. Tools could generate 4D locations as needed from 3+1D. > > == doug foxvog > > >> Geonames >> 52.5243681651343;13.410530090332 >> Displayed as N52 31'27", E13 24'37", and 52.52437 13.41053 >> http://sws.geonames.org/2950159/ >> >> >> New York Times 52.6166667, 13.4 as geo: lat, long >> http://data.nytimes.com/N50987186835223032381 >> >> >> DBpedia - 52.500557, 13.398889 as geo:lat long >> AND 52 30' 2" 13 23' 56" as dbpprop:latd, latm, lats, longd, longm, >> longs >> >> http://dbpedia.org/resource/Berlin >> >> Freebase 52.52334 13.41269, contained by Germany, Europe >> http://rdf.freebase.com/ns/guid.9202a8c04000641f80000000000094d6 >> >> The positions agree within about 1 km in longitude, but in longitude the >> variation is of the order of 10 km. >> >> Sean Barker >> Bristol, UK >> >> >>> -----Original Message----- >>> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx >>> [mailto:ontolog-forum-bounces@xxxxxxxxxxxxxxxx] On Behalf Of Chris >>> Partridge >>> Sent: 26 October 2010 12:46 >>> To: '[ontolog-forum] ' >>> Subject: Re: [ontolog-forum] Fw: GPS coordinates in an ontology? >>> >>> >>> *** WARNING *** >>> >>> This message has originated outside your organisation, >>> either from an external partner or the Global Internet. >>> Keep this in mind if you answer this message. >>> >>> >>> Hi, >>> >>> Ian mentions below I had done some work in this area. >>> >>> As Sean said earlier, it is useful to distinguish between the object >>> being represented and its representation. >>> As Ian points out below, it can take some effort to be sure what object >>> is being presented. >>> >>> The team found that it is often geo-spatial (all three dimensions) and >>> temporal data - rather than just spatial data that is of interested (at >>> least in the defence domain we were working in). We are often interested >>> in the things that stay in the same place (place? See Aristotle for more >>> details) over time. >>> Maybe because we have a 4D bias :-) we found a 4D approach useful. >>> I give some pointers to the 4D approach below. >>> A geo-spatial (all three dimensions) and temporal position (point) is a >>> point in 4D. >>> So (as Ian says below) if we were not interested in the temporal >>> co-ordinate >>> - in programming terms, it was stripped out - then we have a point in 3D >>> (with an associated time) and a line in 4D. >>> If (as Ian says below) we were not interested in the altitude >>> co-ordinate - in programming terms, it was stripped out - then we have a >>> line in 3D (with an associated time) and 4D. >>> There were the standard issues about whether the line was the tangent to >>> the normal of some reference ellipsoid or through some notional centre >>> of the earth. >>> If we were not interested in either the altitude or temporal >>> co-ordinates, then we have a line in 3D and a plane in 4D. >>> >>> Interestingly we found that taking the 4D approach revealed some >>> potential improvements in airspace management. >>> We were interested and amused to find the term 4DATM (4D Air Traffic >>> Management) is in use - whereas from our perspective this follows the >>> traditional 3D + 1 approach (i.e. it is not 4D in our sense of the >>> word). >>> Our take on this was that this recognised the importance of looking at >>> space and time together (for things like ATM) but did not make the >>> (paradigm?) shift from 3D + 1 to 4D. >>> >>> Regards, >>> Chris >>> >> snip >> >> >> >> _________________________________________________________________ >> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/ >> Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/ >> Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx >> Shared Files: http://ontolog.cim3.net/file/ >> Community Wiki: http://ontolog.cim3.net/wiki/ >> To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J >> To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx >> >> > > ============================================================= > doug foxvog doug@xxxxxxxxxx http://ProgressiveAustin.org > > "I speak as an American to the leaders of my own nation. The great > initiative in this war is ours. The initiative to stop it must be ours." > - Dr. Martin Luther King Jr. > ============================================================= > > > _________________________________________________________________ > Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/ > Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/ > Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx > Shared Files: http://ontolog.cim3.net/file/ > Community Wiki: http://ontolog.cim3.net/wiki/ > To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J > To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx > > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please visit http://www.messagelabs.com/email > ______________________________________________________________________ > _______________________________________________________________ Steffen Lindek | Rightscom | Linton House | 164-180 Union Street | London SE1 0LH, UK steffen.lindek@xxxxxxxxxxxxx | www.rightscom.com _______________________________________________________________    (04) The information contained in this e-mail is confidential and may be privileged. 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The statements and opinions expressed in this message are those of the author and do not necessarily reflect those of the company.    (05) Rightscom Limited is registered in England & Wales, registered number 388 7651, registered office Linton House, 164-180 Union Street, London SE1 0LH.    (06) _________________________________________________________________ Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/ Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/ Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx Shared Files: http://ontolog.cim3.net/file/ Community Wiki: http://ontolog.cim3.net/wiki/ To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (07) ```
 Current Thread [ontolog-forum] Fw: Fw: GPS coordinates in an ontology?, sean barker Re: [ontolog-forum] GPS coordinates in an ontology?, doug foxvog Re: [ontolog-forum] GPS coordinates in an ontology?, Chris Partridge Re: [ontolog-forum] GPS coordinates in an ontology?, Steffen Lindek <= Re: [ontolog-forum] GPS coordinates in an ontology?, John F. Sowa Re: [ontolog-forum] RIF vs Ontology, Pavithra Re: [ontolog-forum] RIF vs Ontology, Adrian Walker Re: [ontolog-forum] Webs and Fabrics, John F. Sowa Re: [ontolog-forum] Webs and Fabrics, Pavithra Re: [ontolog-forum] Webs and Fabrics, Jack Park Re: [ontolog-forum] GPS coordinates in an ontology?, Steffen Lindek Re: [ontolog-forum] GPS coordinates in an ontology?, doug foxvog Re: [ontolog-forum] GPS coordinates in an ontology?, Chris Partridge