[GRASSLIST:10504] Re: importing projection info with v.in.ogr

[Chris Fonnesbeck]

On 2/21/06, Tom Russo <russo at bogodyn.org> wrote:
> On Tue, Feb 21, 2006 at 06:42:57PM -0500, we recorded a bogon-computron collision of the <fonnesbeck at gmail.com> flavor, containing:
> >
> > However, when I try to import layers from another location (with a
> > different projection) using v.proj, I get an error:
> >
> > Input Projection Parameters: +proj=latlong +a=6378137
> > +rf=298.257222101 +no_defs
> > +nadgrids=/Applications/Grass/grass61cvs.app/Contents/Resources/grass-6.1.cvs/etc/nad/FL
> >
> > Output Projection Parameters: +proj=aea +lat_1=24 +lat_2=31.5
> > +lat_0=24 +lon_0=-84 +x_0=400000 +y_0=0 +no_defs +a=6378137
> > +rf=298.2572221010002
> > pj_transform() failed
> > cause: failed to load NAD27-83 correction file
> > Error in pj_do_transform
>
> Every time I've seen this error it has been because of a mistaken attempt
> to datum shift values that lie outside the range in which NAD27 datum shift
> grids apply.  For example, attempting to transform the coastline of all
> of North America (including Alaska) using the CONUS grid (which is only defined
> over the lower 48).  You're apparently using a Florida grid --- are your
> vectors absolutely, positively within the bounds of that grid?
>
> AFAICT, the FL grid is only valid from -88deg longitude to -80deg longitude and
> from 24deg latitude to 32deg latitude.  If your vectors have any points that
> lie outside this region the proj.4 library will puke trying to datum shift.

Well, I was importing a FL shoreline vector layer, which you would
think would be within the FL grid, but I could be wrong.

C.

--
Chris Fonnesbeck + Atlanta, GA + http://trichech.us