Re[Gvsig_english] projection Roma40-Gauss Boaga to WGS84

[Javier Galán]

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
>
>
> Cristina Bedoya wrote:
>   
>> Hi Michele,
>>
>> The steps you need to do for reprojecting are:
>>
>> 1. Open gvSIG and create new View
>>
>> 2. Go to the properties of the View and verify that de units of measure 
>> and map are in meters and that the current projection is the EPSG:3003 
>> (MonteMario/Italyzone1)
>>
>> 3. Open the View and add the layer "Iglesias_3003.shp"
>>
>> 4. Then, open the geoprocess of reprojection. And complete:
>>     - The layer of entry must be: "Iglesias_3003.shp"
>>     - Current projection must appear: EPSG:3003
>>     - Destination projection you must:
>>         - Select RS of the layer type EPSG
>>         - Select EPSG: 4326 (WGS84)
>>         - Select the EPSG transformation and then select the button below.
>>         - Select the transformation with code 1169 or 1662 (Sardinia) 
>> and Finish.
>>
>> 5. Save the output layer (Iglesias_4326_transf1169.shp) and Accept. (The 
>> new layer should not be charged in the same View because it's in a 
>> different RS, developers are already aware of this problem to solve in 
>> future versions)
>>
>> 6. Then creates a new View and open the properties, select EPSG:4326 as 
>> a projection of the View.
>>
>> 7. Open the View and load the new layer (Iglesias_4326_transf1169.shp) 
>> and the comparing layer (Iglesias_4326.shp)
>>
>> 8. Using the tool for measuring distances of gvSIG, you'll see that the 
>> layers ara far around 5 meters.
>>
>> To make sure that the transformation made by gvSIG is correct, we've 
>> compared the transformed layer (Iglesias_4326_transf1169.shp) with some 
>> WMS services and far around 50 meters.
>>
>> Unfortunately we've not found any WFS service in the Sardinia area in 
>> EPSG:4326 to compare the results, if you know a WFS service, you might 
>> indicate us.
>>
>> I hope you solved your problem with this steps, if not, please tell us 
>> about what operating system are you working, what version of gvSIG + 
>> extensions are you using and if you're comparing the result layer with 
>> WFS or WMS service, tell us the URL.
>>
>> Greetings,
>>
>> Cris
>>
>>
>>
>>
>> Michele Beneventi wrote:
>>     
>>> Hi Cris,
>>> first of all thanks for your kind answer.
>>> I attach here two layers: one of them is the one in EPSG:3003, while 
>>> the other is the one in EPSG:4326 (this second is the comparing 
>>> layer). I've found that the reprojection geoprocess makes a mistake of 
>>> about 150 meters while using the EPSG transformation coding 1662.
>>> Thanks a lot, I'll wait for your answer.
>>>
>>> Michele
>>>
>>>   
>>>
>>> On Tue, Aug 26, 2008 at 2:05 PM, Cristina Bedoya <bedoya_cri at gva.es 
>>> <mailto:bedoya_cri at gva.es>> wrote:
>>>
>>>     Hi Michele,
>>>
>>>     To help, we need more information, if you want, you can send to us
>>>     the layer that you are transformating (RS "Roma40 - Gauss Boaga"
>>>     (EPSG: 3003)) and the layer with which you are comparing the data
>>>     processed.
>>>
>>>     Greetings,
>>>
>>>     Cris
>>>
>>>
>>>
>>>
>>>     Michele Beneventi wrote:
>>>
>>>         Hi list,
>>>         I have a problem concerning the geoprocess of "reprojection".
>>>         I've had to reproject a polygonal layer from the RS "Roma40 -
>>>         Gauss Boaga" (EPSG:3003) to the RS "WGS84" (EPSG:4326): for
>>>         this I've used the geoprocess of "reprojection" both with the
>>>         transformation "Monte Mario to WGS84 (1)" (EPSG: 1169) and
>>>         with the transformation "Monte Mario to WGS84 (2)" (EPSG:
>>>         1662), which are peculiar for the region of Sardinia.
>>>         Unfortunately the results obtained have shown to be quite bad:
>>>         actually the mean error is around 90 m. Am I making a mistake
>>>         with the settings of the geoprocess, or some other mistake?
>>>
>>>         Thanks a lot, hope to read from you soon.
>>>
>>>         -- 
>>>         Michele Beneventi
>>>
>>>        
>>> ------------------------------------------------------------------------
>>>
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>>>         <mailto:Gvsig_internacional at runas.cap.gva.es>
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>>>
>>>       
>> -- 
>> Cristina Bedoya Pellicé
>> Proyecto gvSIG
>> Conselleria de Infraestructuras y Transportes (GVA).
>> Valencia (Spain)
>>
>>
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>>
>>
>>     
>
>   


-- 
Javier Galán Sánchez
Proyecto gvSIG
Consellería de Infraestructuras y Transportes (GVA)
Valencia (España)