>it is used to transform from one ellipsoid (e.g. WGS84) to another >ellipsoid (e.g. Clarke 1866). (actually on the geotools page they speak >of spheroid instead ellipsoid, where the latter is a specialisation) > >and - i am not really sure, but there is second method that can be used >for such transformation. But anyway.. as far as i know the use of >Bursa-Wolf is quite common. > >if you stay with the ellipsoid you should not need to define params (or >maybe they are zero?) > > Bursa-Wolf transform is used to change from one datum to another. It is a 3-dimensional affine transformation between geocentric coordinates and it is not direcly related to ellipsoid, except that often, different datum use different ellipsoids, and you have also to transform from/to geocentric to/from geographic coordinates using appropriate ellipsoids. There are other methods like coordinate frame rotation which is about the same but with inverse sign convention (which is quite vicious), or even a direct transformation to go from datum1/ellipsoid1/geographic coordinate to datum2/ellipsoid2/geographic coordinate, but I think this one accept only translation between datums, no rotation...
Michael >stefan > > > >>That is one of our most common questions: >>- http://docs.codehaus.org/display/GEOTDOC/11+Referencing+FAQ >> >>My impression is that this is scary math I never quite understood. The >>javadocs describe it all detail (and have links to papers etc..). >> >>On a pragmatic side: Bursa Wolf Parameters defines a transform; and you >>can include the definition of a transform with your crs. At the very >>least it is nice to have a transform defined to take you to >>DefaultGeographic.WSG84. >> >>Jody >> >>------------------------------------------------------------------------- >>This SF.net email is sponsored by: Microsoft >>Defy all challenges. Microsoft(R) Visual Studio 2005. >>http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ >>_______________________________________________ >>Jump-pilot-devel mailing list >>Jump-pilot-devel@lists.sourceforge.net >>https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >> >> >> >> > >------------------------------------------------------------------------- >This SF.net email is sponsored by: Microsoft >Defy all challenges. Microsoft(R) Visual Studio 2005. >http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ >_______________________________________________ >Jump-pilot-devel mailing list >Jump-pilot-devel@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > > > ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
