A bit more digging
NTv2GridShiftFactory fac = new NTv2GridShiftFactory();
URL url = fac.getClass().getResource("shtransntv2.gsb");
System.out.println(fac.isNTv2Grid(url));
GridShiftFile grid = fac.createNTv2Grid(url);
System.out.println(grid);
gives
Headers : 11
Sub Hdrs : 11
Sub Grids: 1
Type : SECONDS
Version : NTv2.0
Fr Ellpsd: DHDN90
To Ellpsd: ETRS89
Fr Maj Ax: 6377397.155
Fr Min Ax: 6356078.963
To Maj Ax: 6378137.0
To Min Ax: 6356752.314
so it looks like that transform will only be used between DHDN geoids (
http://epsg.io/4314-15949) and ETRS89 - so it might work with DHDN /
3-degree Gauss-Kruger zone 3 (E-N) (http://epsg.io/5677)
Ian
On Wed, 8 Apr 2020 at 13:32, Ian Turton <ijtur...@gmail.com> wrote:
> On further investigation at epgs.io I can get a gsb transform for
> epsg:31467->epsg:4326 (WGS84) using BETA2007.gsb but not the epsg:4258
> (ETRS) which is the base for EPSG:4647 (ETRS89 / UTM zone 32N (zE-N)).
>
> I can't find any reference to the need for a grid file for this transform
> so that may be why it isn't picked up by the code? Are you sure this
> transform is in the EPSG tables?
>
> Ian
>
> On Wed, 8 Apr 2020 at 05:55, Benjamin Sokolowski <
> benjamin.sokolow...@data-experts.de> wrote:
>
>> With and without gsb file the same output:
>>
>> CONCAT_MT[INVERSE_MT[PARAM_MT["Transverse_Mercator",
>> PARAMETER["semi_major", 6377397.155],
>> PARAMETER["semi_minor", 6356078.962818189],
>> PARAMETER["central_meridian", 9.0],
>> PARAMETER["latitude_of_origin", 0.0],
>> PARAMETER["scale_factor", 1.0],
>> PARAMETER["false_easting", 3500000.0],
>> PARAMETER["false_northing", 0.0]]],
>> PARAM_MT["Ellipsoid_To_Geocentric",
>> PARAMETER["dim", 2],
>> PARAMETER["semi_major", 6377397.155],
>> PARAMETER["semi_minor", 6356078.962818189]],
>> PARAM_MT["Affine",
>> PARAMETER["num_row", 4],
>> PARAMETER["num_col", 4],
>> PARAMETER["elt_0_0", 1.00000255],
>> PARAMETER["elt_0_1", 0.00001356027323924231],
>> PARAMETER["elt_0_2", 0.00000027634450290912],
>> PARAMETER["elt_0_3", 612.4],
>> PARAMETER["elt_1_0", -0.00001356027323924231],
>> PARAMETER["elt_1_1", 1.00000255],
>> PARAMETER["elt_1_2", 0.00000026180005538759],
>> PARAMETER["elt_1_3", 77.0],
>> PARAMETER["elt_2_0", -0.00000027634450290912],
>> PARAMETER["elt_2_1", -0.00000026180005538759],
>> PARAMETER["elt_2_2", 1.00000255],
>> PARAMETER["elt_2_3", 440.2]],
>> PARAM_MT["Geocentric_To_Ellipsoid",
>> PARAMETER["dim", 2],
>> PARAMETER["semi_major", 6378137.0],
>> PARAMETER["semi_minor", 6356752.314140356]],
>> PARAM_MT["Transverse_Mercator",
>> PARAMETER["semi_major", 6378137.0],
>> PARAMETER["semi_minor", 6356752.314140356],
>> PARAMETER["central_meridian", 9.0],
>> PARAMETER["latitude_of_origin", 0.0],
>> PARAMETER["scale_factor", 0.9996],
>> PARAMETER["false_easting", 32500000.0],
>> PARAMETER["false_northing", 0.0]]]
>>
>> which i think, is the default transformation of geotools. Here's the gsb
>> file
>>
>>
>> Benjamin
>>
>>
>>
>> Von: "Ian Turton" <ijtur...@gmail.com>
>> An: "Benjamin Sokolowski" <benjamin.sokolow...@data-experts.de>
>> Kopie: "geotools-users" <geotools-gt2-users@lists.sourceforge.net>
>> Datum: 07.04.2020 15:53
>> Betreff: Re: Re: Re: [Geotools-gt2-users] Coordinate
>> Transformation
>> ------------------------------
>>
>>
>>
>> Can you try this program with and without the GSB file
>>
>> import org.geotools.referencing.CRS;
>> import org.opengis.referencing.FactoryException;
>> import org.opengis.referencing.NoSuchAuthorityCodeException;
>> import org.opengis.referencing.crs.CoordinateReferenceSystem;
>> import org.opengis.referencing.operation.MathTransform;
>>
>> public class gridShiftTest {
>>
>> public static void main(String[] args) throws
>> NoSuchAuthorityCodeException, FactoryException {
>>
>> CoordinateReferenceSystem sourceCRS = CRS.decode( "EPSG:31467" );
>> CoordinateReferenceSystem targetCRS = CRS.decode( "EPSG:4647" );
>> MathTransform transform = CRS.findMathTransform(sourceCRS, targetCRS);
>>
>> System.out.println(transform);
>> }
>>
>> }
>>
>> Or mail me the gsb file if you can and I'll try - I don't seem to have a
>> grid file for this transformation on my system because I've mainly used UK
>> and USA ones in the past.
>>
>> Ian
>>
>> On Tue, 7 Apr 2020 at 13:21, Benjamin Sokolowski <
>> *benjamin.sokolow...@data-experts.de*
>> <benjamin.sokolow...@data-experts.de>> wrote:
>> Hi Ian,
>>
>> even with the .gsb in the new folder with your given name, no changes at
>> all. Same wrong results. Do you have another idea what i'm missing? The
>> "epsg_operations.properties" is not mandatory right? I don't have that
>> right now.
>>
>> Benjamin
>>
>>
>>
>> Von: "Ian Turton" <*ijtur...@gmail.com* <ijtur...@gmail.com>>
>> An: "Benjamin Sokolowski" <*benjamin.sokolow...@data-experts.de*
>> <benjamin.sokolow...@data-experts.de>>
>> Kopie: "geotools-users" <
>> *geotools-gt2-users@lists.sourceforge.net*
>> <geotools-gt2-users@lists.sourceforge.net>>
>> Datum: 07.04.2020 11:33
>> Betreff: Re: Re: [Geotools-gt2-users] Coordinate Transformation
>> ------------------------------
>>
>>
>>
>> I've never tried adding a gsb file directly to the jar file, I usually
>> create the folder
>> src/main/resources/org/geotools/referencing/factory/gridshift
>> in my project and store the file in there.
>>
>> Ian
>>
>> On Tue, 7 Apr 2020 at 10:14, Benjamin Sokolowski <
>> *benjamin.sokolow...@data-experts.de*
>> <benjamin.sokolow...@data-experts.de>> wrote:
>> Hi Ian,
>>
>> thanks for the reply. Found the discussion at stackexchange already, but
>> it didn't help me. Maybe i didn't understand it correctly.
>> >> *where exactly did you put it?*
>> Do you mean in which jar-File? gt-referencing-16.0.jar
>> I only have geotools in the build path, not the sources.
>>
>> Benjamin
>>
>>
>>
>> Von: "Ian Turton" <*ijtur...@gmail.com* <ijtur...@gmail.com>>
>> An: "Benjamin Sokolowski" <*benjamin.sokolow...@data-experts.de*
>> <benjamin.sokolow...@data-experts.de>>
>> Kopie: "geotools-users" <
>> *geotools-gt2-users@lists.sourceforge.net*
>> <geotools-gt2-users@lists.sourceforge.net>>
>> Datum: 07.04.2020 11:06
>> Betreff: Re: [Geotools-gt2-users] Coordinate Transformation
>> ------------------------------
>>
>>
>>
>> Have a look at
>> *https://gis.stackexchange.com/questions/313512/specifying-epsg-transformation-method-in-geotools/313523#313523*
>> <https://gis.stackexchange.com/questions/313512/specifying-epsg-transformation-method-in-geotools/313523#313523>
>> for
>> an example.
>>
>> When you say you added the .gsb to
>> 'org.geotools.referencing.factory.gridshift'
>> where exactly did you put it?
>>
>> Ian
>>
>> On Tue, 7 Apr 2020 at 09:33, Benjamin Sokolowski <
>> *benjamin.sokolow...@data-experts.de*
>> <benjamin.sokolow...@data-experts.de>> wrote:
>> Hello,
>>
>> first time posting. Hope you guys can help.
>> I want to transform coordinates (point geometry) from Gauß Krueger Zone 3
>> to ETRS:89 UTM32 using geotools and a grid file, which i already have. How
>> exactly do i do this?
>>
>> I already got the codelines:
>> CoordinateReferenceSystem sourceCRS = CRS.*decode*( "EPSG:31467" );
>> CoordinateReferenceSystem targetCRS = CRS.*decode*( "EPSG:4647" );
>> MathTransform transformation = CRS.*findMathTransform*( sourceCRS,
>> targetCRS );
>> Geometry result = JTS.*transform*( geometry, transformation );
>>
>> and put the .gsb to 'org.geotools.referencing.factory.gridshift', but
>> that doesn't seem to work. Geotools is still using the default
>> Transformation, not the more precise with the grid file.
>>
>> Best regards
>> Benjamin Sokolowski_______________________________________________
>> GeoTools-GT2-Users mailing list
>> *GeoTools-GT2-Users@lists.sourceforge.net*
>> <GeoTools-GT2-Users@lists.sourceforge.net>
>> *https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users*
>> <https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users>
>>
>>
>> --
>> Ian Turton
>>
>>
>>
>> --
>> Ian Turton
>>
>>
>>
>> --
>> Ian Turton
>>
>>
>
> --
> Ian Turton
>
--
Ian Turton
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