[Qgis-user] Transformation using NTv2 grids

[Marco Hugentobler]

Hi

>Would it be possible to define a "Custom CRS" for the source CRS containing the
>nadgrids-stuff for doing ntv2 transformation in QGIS 2.0.1?


Yes, it is possible to work with custom CRS (although it is not so 
convenient).

>Is this already in 2.1?
>If yes, where could one find it?


There is a dialog showing the available datum transformations. This 
dialog shows up as soon as a layer needs a datum transformation (e.g. if 
on-the-fly reprojection is toggled or when doing save as'). However, the 
ntv2 transformation info has to be inserted into srs.db / table 
datum_transform first.

Regards,
Marco

On 05.02.2014 15:42, Robert Nuske wrote:
> Hi Marco,
>
>> QGIS 2.2 will have support for NTv2 datum transformations as a core
>> function.
> Is this already in 2.1?
> If yes, where could one find it?
>
>
> Would it be possible to define a "Custom CRS" for the source CRS containing the
> nadgrids-stuff for doing ntv2 transformation in QGIS 2.0.1?
>
> For example GK3:
> "+proj=tmerc +lat_0=0 +lon_0=9 +k=1.000000 +x_0=3500000 +y_0=0 +ellps=bessel
> +units=m +nadgrids=BETA2007.gsb +wktext"
>
>
> cheers,
>    robert
>
>
>> On 05.02.2014 13:34, Burgstaller Stefan wrote:
>>> Hi,
>>>
>>> is it already possible to reproject shape-files using NTv2 grids? I
>>> was looking for appropriate plugins, help documents and already
>>> available tools but I have not found anything. Since the federal
>>> states in Germany start to convert their geospatial data from
>>> Gauss-Kruger to ETRS89 with NTv2 grids this topic becomes more and
>>> more urgent.
>>>
>>> Greetings,
>>>
>>> Stefan Burgstaller
>>>
>>>
>>>
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-- 
Dr. Marco Hugentobler
Sourcepole -  Linux & Open Source Solutions
Weberstrasse 5, CH-8004 Zürich, Switzerland
marco.hugentobler at sourcepole.ch http://www.sourcepole.ch
Technical Advisor QGIS Project Steering Committee