[GRASS-user] ARC GRID File Won't Import

[Helmut Kudrnovsky]

Hi,

>Despite using the -o flag to change the source coordinates from Lon/Lat to
>the SPCS projection of the destination, that did not work as expected; the
>coordinates of the DEM remain lon/lat.

from the r.in.gdal-manual
http://grass.osgeo.org/grass65/manuals/html65_user/r.in.gdal.html

-o Override projection (use location's projection)

the -o flag isn't designed for reprojection on the fly during data
import.

but for the sitution that you know that the srs (datum/projection) of the data to import and
of the location are the same, but in some different notation. (which is often the case if
you are working with data in Austria/Europe of different data providers).

an example for Austria:

- the shapefile to import comes with the srs in the provided *.prj
(http://spatialreference.org/ref/epsg/31257/prj/)

PROJCS["MGI / Austria GK M28",
GEOGCS["MGI",
DATUM["D_MGI",
SPHEROID["Bessel_1841",6377397.155,299.1528128]],
PRIMEM["Greenwich",0],
UNIT["Degree",0.017453292519943295]],
PROJECTION["Transverse_Mercator"],
PARAMETER["latitude_of_origin",0],
PARAMETER["central_meridian",10.33333333333333],
PARAMETER["scale_factor",1],
PARAMETER["false_easting",150000],
PARAMETER["false_northing",-5000000],
UNIT["Meter",1]]


- the location was created with following proj4-string
(http://spatialreference.org/ref/epsg/31257/proj4/)

+proj=tmerc
+lat_0=0
+lon_0=10.33333333333333
+k=1
+x_0=150000
+y_0=-5000000
+ellps=bessel
+towgs84=577.326,90.129,463.919,5.137,1.474,5.297,2.4232
+units=m
+no_defs

these are the different notations of the same srs, and the -o flag
is designed for this situation.

best regards
Helmut
___________________________________________________________
Schon gehört? WEB.DE hat einen genialen Phishing-Filter in die
Toolbar eingebaut! http://produkte.web.de/go/toolbar
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 1747 bytes
Desc: S/MIME Cryptographic Signature
Url : http://lists.osgeo.org/pipermail/grass-user/attachments/20110730/4983c0cb/smime.bin