- From: Peter Baumann <p.baumann@jacobs-university.de>
- Date: Mon, 1 Jun 2015 17:05:58 +0200
- To: Frans Knibbe <frans.knibbe@geodan.nl>
- CC: Kerry Taylor <Kerry.Taylor@csiro.au>, Alejandro Llaves <allaves@fi.upm.es>, SDW WG Public List <public-sdw-wg@w3.org>
- Message-ID: <556C74D6.6090305@jacobs-university.de>
Hi Frans, On 06/01/15 17:02, Frans Knibbe wrote: > Hello Peter, all, > > So actually we have two definitions of the term 'georeference'? A general > definition (link a spatial thing to a geographical geometry (some > coordinates)), and a narrower definition from ISO 19123? no, it's always the same: coverages are georeferenced objects, like any geo feature. The difference is in _linking_ to a georeferenced object, that was the point of discussion > > And if a coverage in the sense of ISO 19123 has a georeference built in, why > do we need a requirement saying that it should be possible to georeference > coverages? good question - no idea :) Maybe a leftover from the early days of work on this, where someone tried to collect the very basics? > > As you can probably tell, I am still confused. If we keep the requirements as > they are, would it be possible to extend the descriptions so they will be less > confusing? I'm at an OGC meeting this week and ISO TC211 coming week, but can always try to chime in when I get pointed to some item. cheers, Peter > > Greetings, > Frans > > > > 2015-06-01 16:46 GMT+02:00 Peter Baumann <p.baumann@jacobs-university.de > <mailto:p.baumann@jacobs-university.de>>: > > Hi Frans, > > not quite, coverages are built around georeferences. The difference is: > - a coverage (at least the ones we are considering here) _has_ a > georeference built in > - a non-georeferenced object can reference some other object that has a > georeference. > > So a coverage does not need to reference anything for having > geocoordinates, they are part of the coverage object. > > Now let us look into what a "georeference" is. Can be a single point (eg, > a point feature), can be an area (eg, a satellite image). > If some other object links to a point in the sense "I sit where this guy > sits" you can dereference this and get a point location for the linking > object. > If this object links to a coverage in this sense then it will sit where > the image sits: in an area. > > Whether such a link is meaningful depends on what you want. > > -Peter > > > > > On 06/01/15 16:33, Frans Knibbe wrote: >> Hello Alejandro, Kerry, Peter, >> >> I think the intention of the two requirements is dawning on me now: There >> is a need for georeferencing coverage data and sensor data because the >> two models that the WG has indentified as the starting point for further >> work (ISO 19123 for coverage data, SSN for sensor data) do not support >> georeferencing at the moment. >> >> I think it would help if we extend the requirement description a bit to >> make that clear. >> >> Greetings, >> Frans >> >> 2015-05-31 13:03 GMT+02:00 <Kerry.Taylor@csiro.au >> <mailto:Kerry.Taylor@csiro.au>>: >> >> Frans, >> >> I think they are different. Linkability was all about “/different >> facts in different data sets” /whereas the two “georeferenced...” >> requirements are particularly asking that those 2 ontologies include >> georeference capability (ssn, for example, does not in its current >> form – instead it asks you get it from some arbitrary other ontology. >> Users want more help here – they want to be told where to get it from >> – this could be in ssn itself, but more likely we will just decide to >> say in ssn to use whatever we recommend in bp . In this case it is >> perhaps true that the different requirements would collapse to a >> single solution – nevertheless they are different requirements ). >> >> >> >> Kerry >> >> >> >> *From:*Peter Baumann [mailto:p.baumann@jacobs-university.de >> <mailto:p.baumann@jacobs-university.de>] >> *Sent:* Friday, 29 May 2015 3:47 AM >> *To:* Frans Knibbe; Alejandro Llaves >> *Cc:* SDW WG Public List >> *Subject:* Re: Georeferenced sensor and coverage data >> >> >> >> Hi Frans, >> >> not sure, but I understand that "spatial data" has its georeference >> built in (through particular technical means, eg, in the coverage >> model) whereas the linkability text just demands that any data can be >> connected to such georeferenced data: >> >> /"Spatial data on the Web should be linkable (by explicit >> relationships between different facts in different data sets), to >> other spatial data and to or from other types of data."/ >> >> >> best, >> Peter >> >> >> On 05/28/15 18:54, Frans Knibbe wrote: >> >> Hello Alejandro, >> >> >> >> I wonder if there should be separate requirements for >> Georeferenced coverage data >> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#GeoreferencedCoverageData> >> and Georeferenced sensor data >> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#GeoreferencedSensorData>. >> Aren't those requirements covered by the Linkability requirement >> <http://w3c.github.io/sdw/UseCases/SDWUseCasesAndRequirements.html#Linkability>? >> If this requirement is met, anything can be georeferenced. >> >> >> >> Regards, >> >> Frans >> >> >> >> -- >> >> Frans Knibbe >> >> Geodan >> >> President Kennedylaan 1 >> >> 1079 MB Amsterdam (NL) >> >> >> >> T +31 (0)20 - 5711 347 <tel:%2B31%20%280%2920%20-%205711%20347> >> >> E frans.knibbe@geodan.nl <mailto:frans.knibbe@geodan.nl> >> >> www.geodan.nl <http://www.geodan.nl> >> >> disclaimer <http://www.geodan.nl/disclaimer> >> >> >> >> >> >> -- >> >> Dr. Peter Baumann >> >> - Professor of Computer Science, Jacobs University Bremen >> >> www.faculty.jacobs-university.de/pbaumann <http://www.faculty.jacobs-university.de/pbaumann> >> >> mail: p.baumann@jacobs-university.de <mailto:p.baumann@jacobs-university.de> >> >> tel: +49-421-200-3178 <tel:%2B49-421-200-3178>, fax: +49-421-200-493178 <tel:%2B49-421-200-493178> >> >> - Executive Director, rasdaman GmbH Bremen (HRB 26793) >> >> www.rasdaman.com <http://www.rasdaman.com>, mail: baumann@rasdaman.com <mailto:baumann@rasdaman.com> >> >> tel: 0800-rasdaman, fax: 0800-rasdafax, mobile: +49-173-5837882 <tel:%2B49-173-5837882> >> >> "Si forte in alienas manus oberraverit hec peregrina epistola incertis ventis dimissa, sed Deo commendata, precamur ut ei reddatur cui soli destinata, nec preripiat quisquam non sibi parata." (mail disclaimer, AD 1083) >> >> >> >> >> >> >> >> >> -- >> Frans Knibbe >> Geodan >> President Kennedylaan 1 >> 1079 MB Amsterdam (NL) >> >> T +31 (0)20 - 5711 347 <tel:%2B31%20%280%2920%20-%205711%20347> >> E frans.knibbe@geodan.nl <mailto:frans.knibbe@geodan.nl> >> www.geodan.nl <http://www.geodan.nl> >> disclaimer <http://www.geodan.nl/disclaimer> >> > > -- > Dr. Peter Baumann > - Professor of Computer Science, Jacobs University Bremen > www.faculty.jacobs-university.de/pbaumann <http://www.faculty.jacobs-university.de/pbaumann> > mail: p.baumann@jacobs-university.de <mailto:p.baumann@jacobs-university.de> > tel: +49-421-200-3178 <tel:%2B49-421-200-3178>, fax: +49-421-200-493178 <tel:%2B49-421-200-493178> > - Executive Director, rasdaman GmbH Bremen (HRB 26793) > www.rasdaman.com <http://www.rasdaman.com>, mail: baumann@rasdaman.com <mailto:baumann@rasdaman.com> > tel: 0800-rasdaman, fax: 0800-rasdafax, mobile: +49-173-5837882 <tel:%2B49-173-5837882> > "Si forte in alienas manus oberraverit hec peregrina epistola incertis ventis dimissa, sed Deo commendata, precamur ut ei reddatur cui soli destinata, nec preripiat quisquam non sibi parata." (mail disclaimer, AD 1083) > > > > > > -- > Frans Knibbe > Geodan > President Kennedylaan 1 > 1079 MB Amsterdam (NL) > > T +31 (0)20 - 5711 347 > E frans.knibbe@geodan.nl <mailto:frans.knibbe@geodan.nl> > www.geodan.nl <http://www.geodan.nl> > disclaimer <http://www.geodan.nl/disclaimer> > -- Dr. Peter Baumann - Professor of Computer Science, Jacobs University Bremen www.faculty.jacobs-university.de/pbaumann mail: p.baumann@jacobs-university.de tel: +49-421-200-3178, fax: +49-421-200-493178 - Executive Director, rasdaman GmbH Bremen (HRB 26793) www.rasdaman.com, mail: baumann@rasdaman.com tel: 0800-rasdaman, fax: 0800-rasdafax, mobile: +49-173-5837882 "Si forte in alienas manus oberraverit hec peregrina epistola incertis ventis dimissa, sed Deo commendata, precamur ut ei reddatur cui soli destinata, nec preripiat quisquam non sibi parata." (mail disclaimer, AD 1083)
Received on Monday, 1 June 2015 15:06:37 UTC