[Gvsig_english] Problem in WGS 84 to UTM SAD 69 transformation

[Javier Galán]

Hi again

I forget telling you tha you can see the crs Information with the button 
crs info in gvsig or at http://www.epsg-registry.org/

see you


Evemar Wernick escribió:
> Hi, Javier.
>
> Thanks again for your help and patience...
> I've tried both 29172 and 29192 (for 1, 4, 14 epsg transformation, and 
> no transformation), but it doesn't work.
> The EPSG:29172 doesn't fit.
> The EPSG 29182/29192 have precisions about 80-100 meters.
> It's very strange because I compared the results of transformation 
> from EPSG:4326 to:
> - barracao_EPSG_4326_29182_1.shp
> - barracao_EPSG_4326_29182_4.shp
> - barracao_EPSG_4326_29182_14.shp
> - barracao_EPSG_4326_29182_no_transformation.shp
> - barracao_EPSG_4326_29192_1.shp
> - barracao_EPSG_4326_29192_4.shp
> - barracao_EPSG_4326_29192_14.shp
> - barracao_EPSG_4326_29192_no_transformation.shp
> and all of them are in the same position (without any displacement).
>
> I think gvSIG isn't using parameters in transformation...
>
> By the way, how did you find the definition and paramenters of the 
> EPSG codes?
>
> Thanks,
> Evemar
>
>
> Javier Galán escreveu:
>> Hi Evermar,
>>
>> Seeing the parameters I realized that it not the same definition for 
>> the epsg and esri library.
>> The both, in epsg library, that has the same definition as you wrote 
>> are 29172/29192. I'm not sure if there's any difference between them, 
>> but i didn't see any.
>>
>> May be that solve the problem.
>>
>> Regards
>>
>>
>> Evemar Wernick escribió:
>>> Javier,
>>>
>>> Thanks for your answer. I didn't have noticed that using EPSG I 
>>> could set up transformations.
>>>
>>> Unfortunately, it didn't work. I tried to use the 3 transformations 
>>> avaliable to Brasil (1, 4 and 14), and tried also manually set up 
>>> the parameters (to transformation (14): X= -66.87, Y= 4.37, Z= 
>>> -38.52) without success (all the result files are always in the same 
>>> position).
>>>
>>> I'm sending anexed the files used for the test and the results, and 
>>> below the process conversion that I've tried (works in ArcGIS and 
>>> not in gvSIG).
>>>
>>> *** Start ArcGIS process conversion ****
>>>
>>> In ArcGIS, I used the ArcToolBox’s Project tool:
>>>
>>> - Input Dataset or Feature Class: barracao_original_gps_wgs84.shp
>>>
>>> - Input Coordinate System (optional): GCS_WGS_1984  (code:4326)
>>>
>>> /Angular Unit: Degree (0,017453292519943299)
>>> Prime Meridian: Greenwich (0,000000000000000000)
>>> Datum: D_WGS_1984
>>>   Spheroid: WGS_1984
>>>     Semimajor Axis: 6378137,000000000000000000
>>>     Semiminor Axis: 6356752,314245179300000000
>>>     Inverse Flattening: 298,257223563000030000/
>>>
>>> - Output Dataset or Feature Class: barracao_ArcGIS_SAD69_Project14.shp
>>>
>>> - Output Coordinate System: SAD_1969_UTM_Zone_22S  (code:29182)
>>>
>>> /Projection: Transverse_Mercator
>>> False_Easting: 500000,000000
>>> False_Northing: 10000000,000000
>>> Central_Meridian: -51,000000
>>> Scale_Factor: 0,999600
>>> Latitude_Of_Origin: 0,000000
>>> Linear Unit: Meter (1,000000)
>>>
>>> Geographic Coordinate System: GCS_South_American_1969
>>> Angular Unit: Degree (0,017453292519943299)
>>> Prime Meridian: Greenwich (0,000000000000000000)
>>> Datum: D_South_American_1969
>>>   Spheroid: GRS_1967_Truncated
>>>     Semimajor Axis: 6378160,000000000000000000
>>>     Semiminor Axis: 6356774,719195305400000000
>>>     Inverse Flattening: 298,250000000000000000/
>>>
>>> - Geographic Transformation (optional): SAD_1969_To_WGS_1984_14  
>>> (code:1548)
>>>
>>> /GEOGTRAN["SAD_1969_To_WGS_1984_14",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]],GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],METHOD["Geocentric_Translation"],PARAMETER["X_Axis_Translation",-66.87],PARAMETER["Y_Axis_Translation",4.37],PARAMETER["Z_Axis_Translation",-38.52]] 
>>>
>>> /
>>> *** End ArcGIS process conversion ****
>>>
>>>
>>> *** Start gvSIG process conversion ****
>>>
>>> In gvSIG, I used Geoprocess toolbox’s Reproject:
>>>
>>> - Input Cover: barracao_original_gps_wgs84.shp
>>>
>>> - Source Projection: EPSG: 4326
>>>
>>> - Target Projection: EPSG: 29182
>>>
>>> - Select Transformation: EPSG transformation
>>>
>>> <Next>
>>>
>>> - Transformation code: 1548 SAD69 to WGS 84 (14)
>>>
>>> - Output Cover: barracao_gvSIG_SAD69_Project14.shp
>>>
>>> *** End gvSIG process conversion ****
>>>
>>>
>>> Please help. We are planning to use gvSIG in many governamental 
>>> projects and this conversion is fundamental.
>>>
>>> Thanks in advance,
>>>
>>> Evemar Wernick
>>> Brasil
>>> evemar at paranacidade.org.br
>>>
>>>
>>>
>>> Javier Galán escreveu:
>>>> Dear Eveman,
>>>>
>>>> That happens because gvSIG don have a library to do transformation 
>>>> between ESRI definitions.
>>>> What you can do is put the view an data whit an EPSG definition, (I 
>>>> checked that the code is the same)
>>>> and then you can choose the EPSG transformation that better fits to 
>>>> your data.
>>>>
>>>> Regards
>>>>
>>>> Evemar escribió:
>>>>> Hi,
>>>>>
>>>>> I'm facing a similar problem:
>>>>>
>>>>> I received some gps data in WGS 84 (ESRI:4326) coordinate system.
>>>>> When I reproject it to SAD 1969 UTM zone 22S (ESRI:29182) using 
>>>>> gvSIG, it
>>>>> doesn't fit correctly (difference ~100m)
>>>>>
>>>>> When I do the same using ESRI ArcCatalog, using the same 
>>>>> parameters except
>>>>> the "Geographic Transformation" (where I can choose 
>>>>> SAD_1969_To_WGS_1984_14
>>>>> - ESRI:1548), it fits nice.
>>>>>
>>>>> Someone knows how can I set those transformation parameters in 
>>>>> gvSIG? Is it
>>>>> possible?
>>>>>
>>>>> Thanks,
>>>>> Evemar
>>>>> Brasil
>>>>>
>>>>
>>> ------------------------------------------------------------------------ 
>>>
>>>
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>>
>>
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-- 
Javier Galán Sánchez
Proyecto gvSIG
Consellería de Infraestructuras y Transportes (GVA)
Valencia (España)