[GRASSLIST:3670] Re: r.in.gdal error

[Glynn Clements]

Russell Nelson wrote:

> > Dear Grass users,
> >                  I am using grass5.0.0pre2 and gdal-1.1.5. I want to
> > import ERDAS (.img) raster file into my lat-long Location .When I use
> > r.in.gdal to import ERDAS (.img) raster file, it gives the fillowing ERROR
> > It work fine with X-Y Location but I want to import in lat-lon location.
> 
> Anil, please do NOT take my answer for authoritative since I have only
> been using grass for a few weeks.  However, from what I've been able
> to tell, the proper procedure for importing a raster without
> georeferencing information is to create two locations: one lat/lon and
> the other X-Y.  r.in.whatever the raster into the X-Y location, add it
> to an i.group, set the i.target for the raster to be the lat-lon
> location, i.rectify the raster into lat/lon, g.region
> rast=YOUR-RASTER, and d.rast map=YOUR-RASTER .

i.rectify should only be necessary if the raster isn't in a known
projection (e.g. aerial photographs), or if you are unable to
determine the raster's projection.

For a raster which is already in a known projection, you can just
import it into a location with the same projection, then use r.support
to specify the raster's boundaries.

If you wish to use a different projection for analysis, first import
the raster into a location whose projection matches that of the
raster, then use r.proj to re-project it into the destination location.

-- 
Glynn Clements <glynn.clements at virgin.net>