[Proj] ToWGS84 for Germany, NRW?

[Schmitz, Uwe]

Byte,
> 
> Hi,
> 
> I want to convert 4326 to 31466....
> But there is a difference of 50m !!
> 
> I think I need right +towgs84 for Germany , NRW, Rhein-Erft-Kreis ??
> 
for this area you can try:
+towgs84=631,23,451

which you can find documented here:
http://www.bezreg-koeln.nrw.de/brk_internet/organisation/abteilung07_produkte/raumbezug/bezugssystem_uebergaenge/index.html

May be you have to fiddle around with the signs.

Also you can try to use the BeTA2007 NTv2-Grid
with +nadgrids which you can download here:
http://www.crs-geo.eu/nn_124226/crseu/EN/CRS__Description/crs-national__node.html?__nnn=true

Hope that helps.

Regards,
Uwe