[Qgis-user] projection confused during import from Grass to QGIS
Tyler Smith
tyler at plantarum.ca
Mon May 11 14:11:13 PDT 2015
Hi,
I'm exporting some data from Grass 6.4 to QGis as .asc files. The source
location in Grass has the projection:
g.proj -p
-PROJ_INFO-------------------------------------------------
name : Lat/Lon
proj : ll
datum : wgs84
ellps : wgs84
no_defs : defined
-PROJ_UNITS------------------------------------------------
unit : degree
units : degrees
meters : 1.0
I generated the asc file from Grass with:
r.out.ascii input=tri_median at PERMANENT output=tri_median.asc
When I import this into QGis, the layer is flipped east to west - the
atlantic coast of NA appears on the west, rather than the east!
The header appears correct:
tws:~$ head -6 tri_mean.asc
north: 46:53:04.633938N
south: 34:44:13.536462N
east: 68:50:28.1616W
west: 94:51:40.938811W
rows: 1458
cols: 3122
But gdal mis-reads it:
tws:~$ gdalinfo tri_mean.asc
Driver: GRASSASCIIGrid/GRASS ASCII Grid
Files: tri_mean.asc
Size is 3122, 1458
Coordinate System is `'
Origin = (94.000000000000000,46.000000000000000)
Pixel Size = (-0.008327994875080,-0.008230452674897)
Corner Coordinates:
Upper Left ( 94.0000000, 46.0000000)
Lower Left ( 94.0000000, 34.0000000)
Upper Right ( 68.0000000, 46.0000000)
Lower Right ( 68.0000000, 34.0000000)
Center ( 81.0000000, 40.0000000)
Band 1 Block=3122x1 Type=Float32, ColorInterp=Undefined
I also tried opening this map directly from Grass within QGIS using the
Grass plugin. The problem persists - the projection of the map is
flipped east to west when it appears in QGIS.
Have I done something wrong somewhere, or is there a problem with the
Grass 6.4 export or QGis/gdal import?
Thanks!
--
Tyler Smith
plantarum.ca
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