[GRASSLIST:6210] reprojection query
Roy Sanderson
R.A.Sanderson at newcastle.ac.uk
Fri Mar 18 10:02:35 EST 2005
Hello Grass-people
I'm having a few problems reprojecting from lat-lon into Lambert Azimuth
Equal area using r.proj (or s.proj). The reprojected lat-lon maps look
correct in terms of the shapes of the countries (various maps of Europe),
but are offset by about 1000km from where I would have expected. I'll
admit that I don't know a lot about map projection systems, so I may have
incorrectly configured the PROJ_INFO files. r.proj seems to work normally,
giving no strange error messages. Using grass5.4, the g.projinfo gives the
following:
For the lat-lon:
-----------------------------------------------------------
PROJ_INFO file:
name: Latitude-Longitude
datum: etrs89
towgs84: 0.000,0.000,0.000
proj: ll
ellps: grs80
a: 6378137.00000
es: 0.0066943800
f: 298.2572221010
-----------------------------------------------------------
PROJ_UNITS file:
unit: degree
units: degrees
meters: 1.0
-----------------------------------------------------------
and the Lambert AEA
-----------------------------------------------------------
PROJ_INFO file:
name: Lambert Azimuthal Equal Area
datum: etrs89
towgs84: 0.000,0.000,0.000
proj: laea
ellps: grs80
a: 6378137.0000000000
es: 0.0066943800
f: 298.2572221010
lat_0: 55.0000000000
lon_0: 20.0000000000
-----------------------------------------------------------
PROJ_UNITS file:
unit: meter
units: meters
meters: 1.0
-----------------------------------------------------------
Any suggestions would be very helpful.
Many thanks
Roy
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