Quick question. What will happen if there is an official EPSG:0 in the future. Maybe this is unlikely, but problems are guaranteed.
Quoting Michael Bedward <[email protected]>: > -0 from me. > > I understand the need and the rationale but I wish it wasn't necessary > to hijack the EPSG authority. > > Michael > > > On 29 April 2011 09:11, Ian Turton <[email protected]> wrote: >> On 28 April 2011 05:37, Andrea Aime <[email protected]> wrote: >>> Hi, >>> some months ago I started a discussion on GeoServer devel about >>> adding support for a new EPSG code, EPSG:0. >>> (if you want to review that discussion see here: >>> http://osgeo-org.1803224.n2.nabble.com/Generic-cartesian-CRS-code-zero-td6136122.html) >>> >>> ESPG:0 would represent pure cartesian data, lack of any >>> referencing, and would >>> thus be associated to DefaultEngineeringCRS.GENERIC_2D, which is >>> designed to be >>> a lenient wildcard CRS, from the javadoc: >>> >> >> +1 for me (though I can already see newbies being confused by it :-) >>> ---------------- >>> >>> A two-dimensional wildcard coordinate system with x, y axis in metres. >>> At the difference of CARTESIAN_2D, this coordinate system is treated >>> specially by the >>> default coordinate operation factory with loose transformation rules: >>> if no transformation >>> path were found (for example through a derived CRS), then the >>> transformation from this >>> CRS to any CRS with a compatible number of dimensions is assumed to be the >>> identity transform. This CRS is usefull as a kind of wildcard when no >>> CRS were explicitly specified. >>> >>> --------------- >>> >>> The only different would be that this one would be constructed so that it >>> reports being EPSG:0 as being its "name". >>> >>> The idea behind EPSG:0 is to be able to handle non georeferenced data, >>> or data that is expressed in some unkonwn coordinate system. >>> This would allow to natively handle CAD data in vector land and plain >>> images in raster land still using our GeoTools Feature/Coverage concepts, >>> and avoid users to try and force EPSG:4326 in it instead (because >>> it's often >>> the only code they remember). >>> >>> As far as I can see this fits well with our existing code base, >>> that already >>> uses in some places DefaultEngineeringCRS.GENERIC_2D when no >>> native CRS could be found, this work would just give it a name. >>> >>> Gabriel on the old thread raised a good point that the WMS 1.3 >>> spec also has >>> CRS:1 as the identifier to be used for the same purpose. >>> I'm not going to go down that road because this would require >>> making a large >>> amount of changes to many bits of existing code assuming the authority >>> is always going to be ESPG, both in GeoTools and GeoServer. >>> The day we go there and allow the library to function properly >>> without those >>> assumption its going to be easy to add a further alias to that CRS >>> and have it respond as CRS:1 as well. >>> >>> To wrap up, I'd like to add a new authority factory in referencing that >>> adds support for that code and then check that base stores and coverage >>> readers are working properly with it. >>> Since this is an addition it's not going to break code not using it, >>> thus I propose to commit the changes on both trunk and 2.7.x >>> >>> Opinions? >>> >>> Cheers >>> Andrea >>> >>> -- >>> ------------------------------------------------------- >>> Ing. Andrea Aime >>> GeoSolutions S.A.S. >>> Tech lead >>> >>> Via Poggio alle Viti 1187 >>> 55054 Massarosa (LU) >>> Italy >>> >>> phone: +39 0584 962313 >>> fax: +39 0584 962313 >>> >>> http://www.geo-solutions.it >>> http://geo-solutions.blogspot.com/ >>> http://www.youtube.com/user/GeoSolutionsIT >>> http://www.linkedin.com/in/andreaaime >>> http://twitter.com/geowolf >>> >>> ------------------------------------------------------- >>> >>> ------------------------------------------------------------------------------ >>> WhatsUp Gold - Download Free Network Management Software >>> The most intuitive, comprehensive, and cost-effective network >>> management toolset available today. Delivers lowest initial >>> acquisition cost and overall TCO of any competing solution. >>> http://p.sf.net/sfu/whatsupgold-sd >>> _______________________________________________ >>> Geotools-devel mailing list >>> [email protected] >>> https://lists.sourceforge.net/lists/listinfo/geotools-devel >>> >> >> >> >> -- >> Ian Turton >> >> ------------------------------------------------------------------------------ >> WhatsUp Gold - Download Free Network Management Software >> The most intuitive, comprehensive, and cost-effective network >> management toolset available today. Delivers lowest initial >> acquisition cost and overall TCO of any competing solution. >> http://p.sf.net/sfu/whatsupgold-sd >> _______________________________________________ >> Geotools-devel mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/geotools-devel >> > > ------------------------------------------------------------------------------ > WhatsUp Gold - Download Free Network Management Software > The most intuitive, comprehensive, and cost-effective network > management toolset available today. 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