Yeah, I agree with your assessment. I hadn’t realized that you could set the
option externally when I started the thread. I agree with you that the user
likely set it themselves given what you have shown thus far, so I’ll sort it
out with them. Apologies for taking some of your time.
Thanks again,
André
From: Even Rouault <even.roua...@spatialys.com>
Sent: April 22, 2022 13:47
To: Vautour, André (INT) <andre.vaut...@teledyne.com>; gdal-dev@lists.osgeo.org
Subject: Re: [gdal-dev] BAG CRS
External Email
André,
hum ok. it might perhaps be possible that WKT2 could come when extract the
vertical part but I still can't reproduce that trying:
$ gdal_translate autotest/gcore/data/byte.tif byte.bag -a_srs
'COMPOUNDCRS["foo",PROJCRS["NAD27 / UTM zone
11N",BASEGEOGCRS["NAD27",DATUM["North American Datum 1927",ELLIPSOID["Clarke
1866",6378206.4,294.978698213898,LENGTHUNIT["metre",1]]],PRIMEM["Greenwich",0,ANGLEUNIT["degree",0.0174532925199433]],ID["EPSG",4267]],CONVERSION["UTM
zone 11N",METHOD["Transverse Mercator",ID["EPSG",9807]],PARAMETER["Latitude of
natural
origin",0,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8801]],PARAMETER["Longitude
of natural
origin",-117,ANGLEUNIT["degree",0.0174532925199433],ID["EPSG",8802]],PARAMETER["Scale
factor at natural
origin",0.9996,SCALEUNIT["unity",1],ID["EPSG",8805]],PARAMETER["False
easting",500000,LENGTHUNIT["metre",1],ID["EPSG",8806]],PARAMETER["False
northing",0,LENGTHUNIT["metre",1],ID["EPSG",8807]]],CS[Cartesian,2],AXIS["(E)",east,ORDER[1],LENGTHUNIT["metre",1]],AXIS["(N)",north,ORDER[2],LENGTHUNIT["metre",1]],USAGE[SCOPE["Engineering
survey, topographic mapping."],AREA["North America - between 120°W and 114°W -
onshore. Canada - Alberta; British Columbia; Northwest Territories; Nunavut.
Mexico. United States (USA) - California; Idaho; Nevada; Oregon;
Washington."],BBOX[26.93,-120,78.13,-114]],ID["EPSG",26711]],VERTCRS["ellipse",VDATUM["NAD83(2011)
/ UTM zone 10N + ellipse"],CS[vertical,1],AXIS["ellipsoid height
(h)",up,LENGTHUNIT["metre",1]]]]'
$ gdalinfo byte.bag -mdd xml:BAG | grep VERT_CS
<gco:CharacterString>VERT_CS["ellipse",VERT_DATUM["NAD83(2011) /
UTM zone 10N + ellipse",2005],UNIT["metre",1],AXIS["Ellipsoid
height",UP]]</gco:CharacterString>
(the ,2005 here isn't really appropriate. it should rather be ,2002, but such
formulations of CompoundCRS with a VerticalCRS that expressed an ellipsoidal
height are not ISO-19111 compliant)
Anyway if you can find a way to reproduce the issue with a CRS provided through
the GetProjection()/SetProjection() API of GDAL, a fix would be welcome. If it
is the user who provides WKT2 with a manual VAR_VERT_WKT option, then I'd say
it is their responsibility to provide the right value.
Even
Le 22/04/2022 à 18:35, Vautour, André (INT) a écrit :
Sorry Even,
I should have done more research on my end up front before sending this. A
client told us his WKT 2.0 BAG was created with GDAL. Looking at it some more,
it was the vertical CRS that was WKT 2.0.
Their vertical CRS looked as follows:
<gco:CharacterString>VERTCRS["ellipse",VDATUM["NAD83(2011) / UTM zone 10N +
ellipse"],CS[vertical,1],AXIS["ellipsoid height
(h)",up,LENGTHUNIT["metre",1]]]</gco:CharacterString>
Cheers,
André
From: Even Rouault
<even.roua...@spatialys.com><mailto:even.roua...@spatialys.com>
Sent: April 22, 2022 13:22
To: Vautour, André (INT)
<andre.vaut...@teledyne.com><mailto:andre.vaut...@teledyne.com>;
gdal-dev@lists.osgeo.org<mailto:gdal-dev@lists.osgeo.org>
Subject: Re: [gdal-dev] BAG CRS
External Email
André,
I don't confirm this trying:
$ gdal_translate autotest/gcore/data/byte.tif byte.bag
$ gdalinfo byte.bag -mdd xml:BAG | grep PROJCS
<gco:CharacterString>PROJCS["NAD27 / UTM zone
11N",GEOGCS["NAD27",DATUM["North_American_Datum_1927",SPHEROID["Clarke
1866",6378206.4,294.978698213898,AUTHORITY["EPSG","7008"]],AUTHORITY["EPSG","6267"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4267"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-117],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",0],UNIT["metre",1,AUTHORITY["EPSG","9001"]],AXIS["Easting",EAST],AXIS["Northing",NORTH],AUTHORITY["EPSG","26711"]]</gco:CharacterString>
This is WKT1
I'm wondering if the confusion might come from looking at the CRS reported by
gdalinfo, which will always be WKT2 in recent GDAL versions whatever the
encoding in the source dataset itself ?
Or perhaps you try to write a Geographic 3D CRS ? in which case WKT2 will be
used since there's no WKT1 representation for this
$ gdalwarp -overwrite autotest/gcore/data/byte.tif byte.bag -t_srs EPSG:4979
-ot float32
$ gdalinfo byte.bag -mdd xml:BAG | grep GEOGCRS
<gco:CharacterString>GEOGCRS["WGS 84",ENSEMBLE["World Geodetic
System 1984 ensemble",MEMBER["World Geodetic System 1984
(Transit)"],MEMBER["World Geodetic System 1984 (G730)"],MEMBER["World Geodetic
System 1984 (G873)"],MEMBER["World Geodetic System 1984 (G1150)"],MEMBER["World
Geodetic System 1984 (G1674)"],MEMBER["World Geodetic System 1984
(G1762)"],MEMBER["World Geodetic System 1984 (G2139)"],ELLIPSOID["WGS
84",6378137,298.257223563,LENGTHUNIT["metre",1]],ENSEMBLEACCURACY[2.0]],PRIMEM["Greenwich",0,ANGLEUNIT["degree",0.0174532925199433]],CS[ellipsoidal,3],AXIS["geodetic
latitude
(Lat)",north,ORDER[1],ANGLEUNIT["degree",0.0174532925199433]],AXIS["geodetic
longitude
(Lon)",east,ORDER[2],ANGLEUNIT["degree",0.0174532925199433]],AXIS["ellipsoidal
height (h)",up,ORDER[3],LENGTHUNIT["metre",1]], [... snip ....]
,ID["EPSG",4979]]</gco:CharacterString>
(I see that gdalinfo also issues a "ERROR 1: PROJ: proj_create_compound_crs:
components of the compound CRS do not belong to one of the allowed combinations
of http://docs.opengeospatial.org/as/18-005r4/18-005r4.html#34"; when reading
this, which I suspect comes from the fact that it tries to create a CompoundCRS
from this 3D GeogCRS and the "VERT_CS["unknown", VERT_DATUM["unknown", 2000]]",
so writing 3D GeogCRS isn't really appropriate for BAG)
Even
Le 22/04/2022 à 18:01, Vautour, André (INT) a écrit :
Hi all,
It has just come to my attention that the BAG driver in GDAL is writing the CRS
with a WKT codeSpace and a WKT 2.0 string as the code. While I am fairly sure
we started that incorrect practice here at CARIS with a WKT 1.0 string, this is
the first time I’ve seen a WKT 2.0 string written in there, and I am therefore
concerned about interoperability.
I think we can all agree that what makes the most sense is to write an EPSG
codebase with the EPSG code if we have it, and I think falling back to a WKT
1.0 string if it is not EPSG is a reasonable fallback if it is not EPSG, given
how it has been used in the past, but I am worried that older software won’t
recognize the WKT 2.0 string.
Would you be willing to take a pull request that does that? Worst-case, would
you be fine with changing that WKT 2.0 string to a WKT 1.0 string?
Regards,
André
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