[gdal-dev] NAD27 to NAD83

[Jean-Claude REPETTO]

Le 14/09/2010 16:56, Donnet , Sebastien a écrit :
> Hi,
> I have a bunch of data in NAD27 (lat, lon ascii files) that I would like
> to convert into NAD83.
> How can I do that easily with gdal?
> Up to now I've tried it like this:
> gdaltransform -s_srs NAD27 -t_srs NAD83 < nad27.txt > nad83.txt
> using a nad27.txt that looks like that (tab separated):
> 71.9881 -80.7771
> 71.9880 -80.7199
> 71.8889 -80.9131
> 71.8892 -80.9117
> 71.9041 -80.8410

Hello,

It is easier to use PROJ.4 :

cs2cs -r -s -f "%.4f" +proj=latlong +datum=NAD27 +to +proj=latlong 
+datum=NAD83 < nad27.txt
71.9888	-80.7764 0.0001
71.9887	-80.7192 0.0001
71.8896	-80.9124 0.0001
71.8899	-80.9110 0.0001
71.9048	-80.8403 0.0001

Jean-Claude