thank you Emily & Francis. Answers were very valuable indeed.
kind regards 05 Kasım 2010 02:16 tarihinde Francis Markham <[email protected]> yazdı: > Hi Ahmet, > > My quick Googling hasn't come up with a widely used pre-defined projection > for Turkey that is non zonal (either UTM or Gauss-Kruger), at least not in > the EPSG database. Apparently, MapInfo ships with a Turkish Lambert > projection in its mapinfow.prj file, which is widely available on the web. > I took the parameters from that projection and created an entry on > spatialreference.org as SR-ORG:7006. This can be inserted into PostGIS as a > new SRS as: > > INSERT into spatial_ref_sys (srid, auth_name, auth_srid, proj4text, srtext) > values ( 97006, 'sr-org', 7006, '', 'PROJCS["Turkish Lambert Conformal > (K.Eren - > ED50)",GEOGCS["GCS_European_1950",DATUM["D_European_1950",SPHEROID["International_1924",6378388.0,297.0]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Lambert_Conformal_Conic"],PARAMETER["False_Easting",1003827.0],PARAMETER["False_Northing",-1183453.0],PARAMETER["Central_Meridian",36.0],PARAMETER["Standard_Parallel_1",37.5],PARAMETER["Standard_Parallel_2",40.5],PARAMETER["Scale_Factor",1.0],PARAMETER["Latitude_Of_Origin",25.0],UNIT["Meter",1.0]]'); > > This can then be used as SRS number 97006. > > Note that this projection uses the ED50 datum. If your coordinates are in > WGS84 (the standard for GPS) or some other datum, it might be convenient to > create a new SRS using the above parameters but based on another datum. > > Furthermore, If you are happy to keep your data in geographic coordinates > (lat/lon) you may wish to investigate the Geography type as Emily > suggested. Be aware, however, that this has some cost in terms of speed for > some operations, and not all operations defined in PostGIS for Geometry are > currently available for Geography types. > > Good luck, > > Francis Markham > > 2010/11/5 ahmet temiz <[email protected]> >> >> hello >> >> I was wondering if you could tell me which projection in metric system >> is suitable for whole country (TURKEY) ? >> I thought to use UTM, but it has three different zones. >> >> If you answer me, I will appreciate >> >> regards >> >> >> -- >> Ahmet Temiz >> Jeoloji Müh. >> Planlama ve Zarar Azaltma Dairesi Başkanlığı >> Bilgi ve CBS grubu >> Eskişehir Yolu 10. km. >> Lodumlu / Ankara >> Tel : 0 312 2872680 / 1535 >> _______________________________________________ >> postgis-users mailing list >> [email protected] >> http://postgis.refractions.net/mailman/listinfo/postgis-users > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > -- Ahmet Temiz Jeoloji Müh. Planlama ve Zarar Azaltma Dairesi Başkanlığı Bilgi ve CBS grubu Eskişehir Yolu 10. km. Lodumlu / Ankara Tel : 0 312 2872680 / 1535 _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
