[QGIS-trac] Re: [Quantum GIS] #3788: Problem Datum Transformation
Quantum GIS
qgis at qgis.org
Fri Apr 29 10:56:32 EDT 2011
#3788: Problem Datum Transformation
-----------------------------------------------------------------------------------------------+
Reporter: ImPreZa | Owner: nobody
Type: bug | Status: new
Priority: major: does not work as expected | Milestone: Version 1.7.0
Component: Projection Support | Version: 1.6.0
Keywords: datum transformation SAD69 SIRGAS2000 problem displacement shift brazilian ntv2 | Platform_version: Win7
Platform: Windows | Must_fix: Yes
Status_info: 0 |
-----------------------------------------------------------------------------------------------+
Description changed by jef:
Old description:
> Hey!!
>
> I've tried to transform a shapefile from EPGS:4618 (SAD69) to EPGS:4674
> (SIRGAS2000), but the product of this transformation doesn't shifts. It
> seems that QGIS export a shapefile with the new projection, but it is
> unable to apply (in fact) the values of the new ellipsoid.
>
> Here are the official parameters for transformation between the both
> datums:[[BR]]
> DX = -67,35[[BR]]
> DY = +3,88[[BR]]
> DZ = -38,22[[BR]]
>
> Unfortunately, I couldn't upload the .gsb files (NTV2 transformation,
> 800kb) used by the department of the brazilian government, IBGE, which is
> responsible for cartography etc. But you can download it here
> ([ftp://geoftp.ibge.gov.br/programa/Transformacao_de_Coordenadas/ ProGRID
> IBGE]). You'll find the .gsb files here (C:\Program
> Files\Progrid\GridFiles).
>
> SAD69 Original (SAD69_003.GSB) [[BR]]
> SAD69 reviewed in 1996 (SAD96_003.GSB)
>
> If I open in QGIS a shapefile originally created in ArcGIS in SAD69 and
> other in SIRGAS2000, also transformed from SAD69 to SIRGAS in ArcGIS,
> without activate OTF, I can see the displacement between them. But when I
> transform the ArcGIS-shapefile-SAD69 to SIRGAS2000 in QGIS, the QGIS is
> unable to show their displacement, even with OTF activated. Why does this
> happens with shapes transformed in QGIS?
>
> And the last problem: The QGIS doesn't create properly the .prj file,
> both for SAD69 and SIRGAS2000, as exposed here:
>
> '''SIRGAS2000'''[[BR]]
>
> GEOGCS["GRS 1980(IUGG,
> 1980)",DATUM'''["D_unknown"''',SPHEROID["GRS80",6378137,298.257222101]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]
>
> And the correct one, from ArcGIS is:
>
> GEOGCS["GCS_SIRGAS_2000",DATUM["D_SIRGAS_2000",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]]
>
> '''SAD69:'''[[BR]]
>
> GEOGCS["Australian Natl & S. Amer.
> 1969",DATUM["D_unknown",SPHEROID["aust_SA",6378160,298.25]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]
>
> And the correct one, from ArcGIS is:
>
> GEOGCS["GCS_South_American_1969",DATUM["D_South_American_1969",SPHEROID["GRS_1967_Truncated",6378160.0,298.25]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],VERTCS["WGS_1984_Geoid",VDATUM["WGS_1984_Geoid"],PARAMETER["Vertical_Shift",0.0],PARAMETER["Direction",1.0],UNIT["Meter",1.0]]
>
> Here are the original data that I'm working with. These data are mineral
> rights from Rio Grande do Sul State, south Brazil:
> [http://sigmine.dnpm.gov.br/sad69/RS.zip/ Shapefiles in SAD69]
> [http://sigmine.dnpm.gov.br/sirgas2000/RS.zip/ Shapefiles in SIRGAS]
>
> I asked for help at the QGIS Forum. They've found the same problem and
> couldn't solve it.
> Thanks!!
New description:
Hey!!
I've tried to transform a shapefile from EPGS:4618 (SAD69) to EPGS:4674
(SIRGAS2000), but the product of this transformation doesn't shifts. It
seems that QGIS export a shapefile with the new projection, but it is
unable to apply (in fact) the values of the new ellipsoid.
Here are the official parameters for transformation between the both
datums:
{{{
DX = -67,35
DY = +3,88
DZ = -38,22
}}}
Unfortunately, I couldn't upload the .gsb files (NTV2 transformation,
800kb) used by the department of the brazilian government, IBGE, which is
responsible for cartography etc. But you can download it here
([ftp://geoftp.ibge.gov.br/programa/Transformacao_de_Coordenadas/ ProGRID
IBGE]). You'll find the .gsb files here (C:\Program
Files\Progrid\GridFiles).
{{{
SAD69 Original (SAD69_003.GSB)
SAD69 reviewed in 1996 (SAD96_003.GSB)
}}}
If I open in QGIS a shapefile originally created in ArcGIS in SAD69 and
other in SIRGAS2000, also transformed from SAD69 to SIRGAS in ArcGIS,
without activate OTF, I can see the displacement between them. But when I
transform the ArcGIS-shapefile-SAD69 to SIRGAS2000 in QGIS, the QGIS is
unable to show their displacement, even with OTF activated. Why does this
happens with shapes transformed in QGIS?
And the last problem: The QGIS doesn't create properly the .prj file, both
for SAD69 and SIRGAS2000, as exposed here:
'''SIRGAS2000'''
{{{
GEOGCS["GRS 1980(IUGG,
1980)",DATUM'''["D_unknown"''',SPHEROID["GRS80",6378137,298.257222101]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]
}}}
And the correct one, from ArcGIS is:
{{{
GEOGCS["GCS_SIRGAS_2000",DATUM["D_SIRGAS_2000",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]]
}}}
'''SAD69:'''
{{{
GEOGCS["Australian Natl & S. Amer.
1969",DATUM["D_unknown",SPHEROID["aust_SA",6378160,298.25]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]
}}}
And the correct one, from ArcGIS is:
{{{
GEOGCS["GCS_South_American_1969",DATUM["D_South_American_1969",SPHEROID["GRS_1967_Truncated",6378160.0,298.25]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],VERTCS["WGS_1984_Geoid",VDATUM["WGS_1984_Geoid"],PARAMETER["Vertical_Shift",0.0],PARAMETER["Direction",1.0],UNIT["Meter",1.0]]
}}}
Here are the original data that I'm working with. These data are mineral
rights from Rio Grande do Sul State, south Brazil:
[http://sigmine.dnpm.gov.br/sad69/RS.zip/ Shapefiles in SAD69]
[http://sigmine.dnpm.gov.br/sirgas2000/RS.zip/ Shapefiles in SIRGAS]
I asked for help at the [http://forum.qgis.org/viewtopic.php?t=8358 QGIS
Forum]. They've found the same problem and couldn't solve it.
Thanks!!
--
--
Ticket URL: <https://trac.osgeo.org/qgis/ticket/3788#comment:1>
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