[FWTools] Big NTv2-Grid-File causes problem

[Frank Warmerdam]

Ernst Meier wrote:
> Frank,
> 
> and what's the meaning of %6d?

Ernst,

It means an ascii encoded six character wide field. But that is
not the actual form in the file so I don't know whether that
document is accurate or not.

> I use two different Grids. One small for the whole country with low
> accurancy but even better results (10-20cm) and that big one that should
> have an better accurancy with an offset off 150m.
> 
> The parameters of both calls are the same. I only change the parameter
> +nadgrids.
> 
> The author of the gridfile has tested it within FME and ArcGIS with the
> expected accurancy (3mm).
> 
> Any ideas?

Not really.  It could be lots of things.

You report the results being 150m off.  How far off are they if you use
the @null grid instead?  Have you tried running with PROJ_DEBUG set in the
environment to see what it reports?

Best regards,
-- 
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