remap a grid with laea projection
Added by Natalia L almost 6 years ago
Hello,
I am trying to regrid a grid (netcdf file) with a lambert azimuthal equal area projection to a lambert conformal conic projection grid.
At first, I am trying to create a scrip file and it gives the following error:
cdo remapcon (Abort): proj error: major axis or radius = 0 or not given
cdo setgridtype: Started child process "setgrid,…. (pipe1.1)".
Could anyone help me on how I could remap a LAEA grid?
Thank you!
Replies (4)
RE: remap a grid with laea projection - Added by Karin Meier-Fleischer almost 6 years ago
Hi Natalia,
I'm not an expert on SCRIP but the radius (earth_radius in meter) seems to be undefined in your scrip file. If you already have a lambert conformal conic projection file you can retrieve the grid description with the griddes operator.
cdo griddes lambert_conf_file > gridfile.txt
The grid description file gridfile.txt will be something like
# # gridID 1 # gridtype = projection gridsize = 67725 xsize = 301 ysize = 225 xname = x xunits = "m" yname = y yunits = "m" xfirst = 0 xinc = 20318 yfirst = 0 yinc = 20318 uvRelativeToGrid = 1 grid_mapping = Lambert_Conformal grid_mapping_name = lambert_conformal_conic standard_parallel = 25. longitude_of_central_meridian = 265. latitude_of_projection_origin = 25. earth_radius = 6367470. longitudeOfFirstGridPointInDegrees = 233.862 latitudeOfFirstGridPointInDegrees = 16.281With the grid description file you can remap your data
cdo remapbil,gridfile.txt infile outfile
-Karin
RE: remap a grid with laea projection - Added by Natalia L almost 6 years ago
Hi Karin,
thank you.
Well, I have the file land_use.nc which is a grid in Lambert Azimuthal Equal Area (LAEA) projection.
I have also a database.nc which is in Lambert Conic Conformal (LCC) projection.
I want to remap the land_use.nc to the LCC projection.
In my initial script, I defined the grid description of the target grid (i.e. the LCC projection of land_use.nc). So, I had already defined the earth radius as following:
cat > $Database_outdir/mygrid.txt <<EOF
gridtype = lcc2
gridsize = $GRDSIZE
xname = x
xlongname = x coordinate of projection
xunits = m
yname = y
ylongname = y coordinate of projection
yunits = m
xsize = $dx
ysize = $dy
a = 6370000
lon_0 = $central_lon
lat_0 = $central_lat
lat_1 = $standard_parallel_1
lat_2 = $standard_parallel_2
xfirst = $ORIGX
xinc = $RESX
yfirst = $ORIGY
yinc = $RESY
Do you mean that I have to define also the projection of land_use.nc (LAEA)? Or that I have to use the command -griddes before the scrip file generation?
thank you!
N.
RE: remap a grid with laea projection - Added by Natalia L almost 6 years ago
Also,
I tried the following
cat > $Database_outdir/mygrid.txt <<EOF
gridtype = lcc2
gridsize = $GRDSIZE
xname = x
xlongname = x coordinate of projection
xunits = m
yname = y
ylongname = y coordinate of projection
yunits = m
xsize = $dx
ysize = $dy
a = 6370000.
lon_0 = $central_lon
lat_0 = $central_lat
lat_1 = $standard_parallel_1
lat_2 = $standard_parallel_2
xfirst = $ORIGX
xinc = $RESX
yfirst = $ORIGY
yinc = $RESY
EOF
- CREATE SCRIP FILE
cdo griddes $Database_outdir/land_use.nc > $Database_outdir/mygrid.txt
cdo remapbil,$Database_outdir/mygrid.txt $Database_outdir/g250_clc12_V18_5.nc $Database_outdir/tmpdom_land_use.nc
cdo setgridtype,curvilinear -setgrid,$Database_outdir/mygrid.txt $Database_outdir/tmpdom_g250_clc12_V18_5.nc $Database_outdir/Regrid_g250_clc12_V18_5.nc
and it gets the following error
cdo griddes: Processed 1 variable ( 0.00s )
Warning (gridInqLaea) : LAEA grid undefined (gridID = 23)
Warning (gridInqLaea) : LAEA grid undefined (gridID = 23)
cdo remapbil (Abort): proj error: major axis or radius = 0 or not given
RE: remap a grid with laea projection - Added by Natalia L almost 6 years ago
Natalia L wrote:
Also,
I tried the following
cat > $Database_outdir/mygrid.txt <<EOF
gridtype = lcc2
gridsize = $GRDSIZE
xname = x
xlongname = x coordinate of projection
xunits = m
yname = y
ylongname = y coordinate of projection
yunits = m
xsize = $dx
ysize = $dy
a = 6370000.
lon_0 = $central_lon
lat_0 = $central_lat
lat_1 = $standard_parallel_1
lat_2 = $standard_parallel_2
xfirst = $ORIGX
xinc = $RESX
yfirst = $ORIGY
yinc = $RESY
EOF
- CREATE SCRIP FILE
cdo griddes $Database_outdir/land_use.nc > $Database_outdir/mygrid.txtcdo remapbil,$Database_outdir/mygrid.txt $Database_outdir/land_use.nc $Database_outdir/tmpdom_land_use.nc
cdo setgridtype,curvilinear -setgrid,$Database_outdir/mygrid.txt $Database_outdir/tmpdom_land_use.nc $Database_outdir/Regrid_land_use.ncand it gets the following error
cdo griddes: Processed 1 variable ( 0.00s )
Warning (gridInqLaea) : LAEA grid undefined (gridID = 23)
Warning (gridInqLaea) : LAEA grid undefined (gridID = 23)cdo remapbil (Abort): proj error: major axis or radius = 0 or not given