[Proj] GRS80 vs GRS80 +towgs84=0,0,0

[Maciek Sieczka]

> Maciek,
> 
> In the case you specify the +towgs84, no ellipsoid conversion
> is done.  In the case without +towgs84, an ellipsoid conversion
> is done.  The WGS84 and GRS80 are essentially the same
> but there is a small difference.
> 
>     WGS84 a=6378137.0      rf=298.257223563 WGS 84
>     GRS80 a=6378137.0      rf=298.257222101 GRS 1980(IUGG, 1980)

So the formaly "right" approach is not to use any +towgs84= for GRS80,
is it?

Maciek

Best regards,
Maciek


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