[gdal-dev] Finnish KKJ and MapInfo MIF with GDAL 3.1

Mon May 18 06:23:48 PDT 2020

Thanks, Even.

EPSG:2393 is a Northing-Easting system and I read
    assert wkt == 'PROJCS["unnamed",GEOGCS["unnamed",DATUM["Kartastokoordinaattijarjestelma_1966",SPHEROID["International 1924",6378388,297]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",27],PARAMETER["scale_factor",1],PARAMETER["false_easting",3500000],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH]]'

It is in the test and I don't know if it can make trouble for users.

-Jukka-

Lähettäjä: Even Rouault <even.rouault at spatialys.com>
Lähetetty: maanantai 18. toukokuuta 2020 16.13
Vastaanottaja: gdal-dev at lists.osgeo.org
Kopio: Rahkonen Jukka (MML) <jukka.rahkonen at maanmittauslaitos.fi>
Aihe: Re: [gdal-dev] Finnish KKJ and MapInfo MIF with GDAL 3.1

On lundi 18 mai 2020 11:17:52 CEST Rahkonen Jukka (MML) wrote:

> Hi,

>

> This command

> ogr2ogr -f "MapInfo file" -s_srs epsg:3067 -t_srs epsg:2393 2393.mif

> tm35.jml writes into MIF

> CoordSys Earth Projection 8, 104, "m", 27, 0, 1, 3500000, 0

>

> ogrinfo shows

>

> ogrinfo 2393.mif -al -so

> INFO: Open of `2393.mif'

> using driver `MapInfo File' successful.

>

> Layer name: 2393

> Geometry: Unknown (any)

> Feature Count: 3

> Extent: (3284260.027390, 6962722.914217) - (3284610.369420, 6962941.953889)

> Layer SRS WKT:

> PROJCRS["unnamed",

> BASEGEOGCRS["unnamed",

> DATUM["World Geodetic System 1984",

> ELLIPSOID["WGS 84",6378137,298.257223563,

> LENGTHUNIT["metre",1,

> ID["EPSG",9001]]]],

> PRIMEM["Greenwich",0,

> ANGLEUNIT["degree",0.0174532925199433,

> ID["EPSG",9122]]]],

> CONVERSION["unnamed",

> METHOD["Transverse Mercator",

> ID["EPSG",9807]],

> PARAMETER["Latitude of natural origin",0,

> ANGLEUNIT["degree",0.0174532925199433],

> ID["EPSG",8801]],

> PARAMETER["Longitude of natural origin",27,

> ANGLEUNIT["degree",0.0174532925199433],

> ID["EPSG",8802]],

> PARAMETER["Scale factor at natural origin",1,

> SCALEUNIT["unity",1],

> ID["EPSG",8805]],

> PARAMETER["False easting",3500000,

> LENGTHUNIT["metre",1],

> ID["EPSG",8806]],

> PARAMETER["False northing",0,

> LENGTHUNIT["metre",1],

> ID["EPSG",8807]]],

> CS[Cartesian,2],

> AXIS["easting",east,

> ORDER[1],

> LENGTHUNIT["metre",1,

> ID["EPSG",9001]]],

> AXIS["northing",north,

> ORDER[2],

> LENGTHUNIT["metre",1,

> ID["EPSG",9001]]]]

> Data axis to CRS axis mapping: 1,2

>

> When I convert this data back into EPSG:3067 the coordinates are shifted by

> a hundred meters probably because what was called towgs84 parameters are

> not applied. Parameters appear in the mitab source code

> https://github.com/OSGeo/gdal/blob/master/gdal/ogr/ogrsf_frmts/mitab/mitab_

> spatialref.cpp#L251 { 0, 1016,"Finnish_KKJ", 4, -96.062,

> -82.428, -121.754, -4.801, -0.345, 1.376, 1.496, 0},

>

> I tried to fix the MIF by changing the CoordSys line into

> CoordSys Earth Projection 24, 1016, "m", 27, 0, 1, 3500000, 0

> that is to my knowledge what MapInfo itself is using but that does not work

> at all with GDAL

>

> ogr2ogr -f "jml" -t_srs epsg:3067 2393_alt_from_mif.jml 2393_alt.mif

> ERROR 1: PROJ: proj_as_proj_string: Unsupported conversion method:

> Transverse_Mercator_MapInfo_24 ERROR 6: Cannot find coordinate operations

> from

> `PROJCRS["unnamed",BASEGEOGCRS["unnamed",DATUM["Finnish_KKJ",ELLIPSOID["Int

> ernational

> 1924",6378388,297,LENGTHUNIT["metre",1,ID["EPSG",9001]]]],PRIMEM["Greenwich

> ",0,ANGLEUNIT["degree",0.0174532925199433,ID["EPSG",9122]]]],CONVERSION["unn

> amed",METHOD["Transverse_Mercator_MapInfo_24"],PARAMETER["latitude_of_origin

> ",0,ANGLEUNIT["degree",0.0174532925199433,ID["EPSG",9122]]],PARAMETER["centr

> al_meridian",27,ANGLEUNIT["degree",0.0174532925199433,ID["EPSG",9122]]],PARA

> METER["scale_factor",1,SCALEUNIT["unity",1,ID["EPSG",9201]]],PARAMETER["fals

> e_easting",3500000,LENGTHUNIT["metre",1,ID["EPSG",9001]]],PARAMETER["false_n

> orthing",0,LENGTHUNIT["metre",1,ID["EPSG",9001]]]],CS[Cartesian,2],AXIS["eas

> ting",east,ORDER[1],LENGTHUNIT["metre",1,ID["EPSG",9001]]],AXIS["northing",n

> orth,ORDER[2],LENGTHUNIT["metre",1,ID["EPSG",9001]]]]' to `EPSG:3067' ERROR

> 1: Failed to create coordinate transformation between the

> following coordinate systems. This may be because they

> are not transformable.

>

> Is there something that I could do for making the conversion to round-trip?

Temptative fix for both datum and projection code in

https://github.com/OSGeo/gdal/pull/2577

I presume the separate codes for the TMerc projection on KKJ and the regular one came from using the Snyder's tmerc formula vs using the extended one.

Even

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