[Proj] Using cs2cs.

[Hermann Peifer]

On 30/04/2012 05:54, Joshua Brown wrote:
> Hello,
>
> I have a text file, with each OSGB32 value on a new line.
>
> I want to convert from OSGB32 to WGS84 so I can map values to google earth.
>
> How can I use cs2cs to convert the text file into WGS84?
>

I assume that with OSGB32 you actually mean: OSGB36. I have recently 
been using [1] and [2] for getting from OSGB36 to WGS84. [2] is the more 
accurate alternative. You can find a link to OSTN02_NTv2.gsb at the PROJ 
wiki page, see [3].

Hermann

[1]
cs2cs -v -f "%.6f" +proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 
+x_0=400000 +y_0=-100000 +ellps=airy 
+towgs84=446.448,-125.157,542.06,0.15,0.247,0.842,-20.489 +to 
+proj=longlat +datum=WGS84

[2]
cs2cs -v -f "%.6f" +proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 
+x_0=400000 +y_0=-100000 +ellps=airy +nadgrids=./OSTN02_NTv2.gsb  +to 
+proj=longlat +datum=WGS84

[3] http://trac.osgeo.org/proj/wiki