[Proj] Dutch correction grid

[Jan Hartmann]

Yes, this looks like a detailed description of the NTV2 format. Do you 
know a program to do the conversion, Maxime?

Jan

On 8-4-2011 19:03, Maxime SEGUIN wrote:
> Hi,
>
> You can look at this spreadsheet :
> http://lambert93.ign.fr/fileadmin/files/ntf_r93.pdf
>
> Best regards,
>
> Maxime SEGUIN
>
>
>> On 11-04-08 11:28 AM, Jan Hartmann wrote:
>>> I don't quite understand, Frank. I have a spreadsheet with four columns:
>>> x, y,
>>> correction for x and correction for y. What kind of raster file do I
>>> need to
>>> create with these data?
>> Jan,
>>
>> As input we would require an input raster with two "bands" representing
>> the
>> offset in longitude and latitude.   I'm not sure off hand what the units
>> are - possibly arcseconds?   The input file would need to be georeferenced
>> in latitude and longitude.
>>
>> If your input points are sparse and irregular you could likely use
>> gdal_grid to interpolate a grid from the point data.
>>
>> My point was mainly that you don't necessarily have to write an NTv2
>> "writer" - it is sufficient to get the datum shift data into any GDAL
>> support grid format.
>>
>> Best regards,
>>
>> --
>> ---------------------------------------+--------------------------------------
>> I set the clouds in motion - turn up   | Frank Warmerdam,
>> warmerdam at pobox.com
>> light and sound - activate the windows | http://pobox.com/~warmerdam
>> and watch the world go round - Rush    | Geospatial Programmer for Rent
>>
>> _______________________________________________
>> Proj mailing list
>> Proj at lists.maptools.org
>> http://lists.maptools.org/mailman/listinfo/proj
>>
>
> _______________________________________________
> Proj mailing list
> Proj at lists.maptools.org
> http://lists.maptools.org/mailman/listinfo/proj