[GRASSLIST:2214] Re: Importing a NAD83 map into a NAD27 location.

[Richard Greenwood]

Ben Logan wrote:

>I have some data which uses the nad27 datum (the spheroid is clark66)
>and I created a location based on that.  However, I now have some
>raster maps of the same area which I need to import, and they use
>nad83 (with the grs1980 spheroid).  All the data is UTM zone 17.  Is
>this a problem?  Do I need to do something to convert the new data?
>
>I'm using GRASS 5.0.3 and gdal 1.1.9.
>
>  
>
Nad27 <=> Nad83 should be supported in the configuration that you 
describe. When you run r.proj, one of the first lines should state that 
it is applying the datum shift. If it does not, then you may need to 
tweak your PROJ_INFO file in PERMANENT and add a "datum: nad83" or 
similar statement.

Richard Greenwood