Re[Gvsig_english] projection Roma40-Gauss Boaga to WGS84

Evemar Wernick evemar at paranacidade.org.br
Tue Oct 7 14:44:13 CEST 2008


Javier,

Thanks for your answer. I didn't have noticed that using EPSG I could 
set up transformations.

Unfortunately, it didn't work.

I would like to continue receiving your help, but I think is better not 
pollute the Michele's post so I will start a new post called "Problem in 
WGS 84 to UTM SAD 69 transformation" ok?

Thanks,

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
>>
>>
>> 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
>>>>
>>>>        
>>>> ------------------------------------------------------------------------ 
>>>>
>>>>
>>>>         _______________________________________________
>>>>         Gvsig_internacional mailing list
>>>>         Gvsig_internacional at runas.cap.gva.es
>>>>         <mailto:Gvsig_internacional at runas.cap.gva.es>
>>>>         http://runas.cap.gva.es/mailman/listinfo/gvsig_internacional
>>>>
>>>>       
>>> -- 
>>> Cristina Bedoya Pellicé
>>> Proyecto gvSIG
>>> Conselleria de Infraestructuras y Transportes (GVA).
>>> Valencia (Spain)
>>>
>>>
>>> _______________________________________________
>>> Gvsig_internacional mailing list
>>> Gvsig_internacional at runas.cap.gva.es
>>> http://runas.cap.gva.es/mailman/listinfo/gvsig_internacional
>>>
>>>
>>>     
>>
>>   
>
>


More information about the Gvsig_internacional mailing list