Issue with converting generic coordinate to lonlat one
Added by Beata Szabo-Takacs about 1 year ago
Dear All,
I have a similar problem as in https://code.mpimet.mpg.de/boards/1/topics/3330. I have CT-NRT.2025_mergetime.nc file which has generic grid. I would like to convert it to latlon grid for using sellonlatbox. I tried the following methods:
cdo griddes CT-NRT.2025_mergetime.nc > mygrid_CT-NRT
sed -i "s/generic/lonlat/g" mygrid_CT-NRT
cdo setgrid,mygrid_CT-NRT CT-NRT.v2025_mergetime.nc CT-NRT.v2025_mergetime_fixedgrid2.nc
- gridID 1
#
gridtype = lonlat
gridsize = 10800
xsize = 120
ysize = 90
xname = longitude
xlongname = "longitude"
xunits = "degrees_east"
yname = latitude
ylongname = "latitude"
yunits = "degrees_north"
xfirst = -178.5
xinc = 3
yfirst = -89
yinc = 2
scanningMode = 64 # - gridID 2
#
gridtype = lonlat
gridsize = 6
xsize = 6
scanningMode = 64 # - gridID 3
#
gridtype = lonlat
gridsize = 1
scanningMode = 64
The result of cdo sinfo CT-NRT.v2025_mergetime_fixedgrid2.nc is:
File format : NetCDF4
-1 : Institut Source T Steptype Levels Num Points Num Dtype : Parameter ID
1 : unknown unknown v instant 34 1 10800 1 F32 : -1
2 : unknown unknown v instant 1 2 10800 1 F32 : -2
3 : unknown unknown v instant 1 2 6 2 I32 : -3
4 : unknown unknown v instant 34 1 10800 1 F32 : -4
5 : unknown unknown v instant 1 2 1 3 F64 : -5
6 : unknown unknown v instant 35 3 10800 1 F32 : -6
7 : unknown unknown c instant 1 2 10800 1 F32 : -7
8 : unknown unknown v instant 1 2 10800 1 F32 : -8
9 : unknown unknown v instant 35 3 10800 1 F32 : -9
10 : unknown unknown v instant 34 1 10800 1 F32 : -10
11 : unknown unknown v instant 34 1 10800 1 F32 : -11
12 : unknown unknown v instant 34 1 10800 1 F32 : -12
13 : unknown unknown v instant 34 1 10800 1 F32 : -13
Grid coordinates :
1 : lonlat : points=10800 (120x90)
longitude : -178.5 to 178.5 by 3 degrees_east circular
latitude : -89 to 89 by 2 degrees_north
2 : generic : points=6
3 : generic : points=1
Vertical coordinates :
1 : generic : levels=34
level : 1 to 34 by 1 none
2 : surface : levels=1
3 : generic : levels=35
boundary : 1 to 35 by 1 none
Time coordinate : 248 steps
RefTime = 2000-01-01 00:00:00 Units = days Calendar = standard
YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss YYYY-MM-DD hh:mm:ss
2024-03-01 01:30:00 2024-03-01 04:30:00 2024-03-01 07:30:00 2024-03-01 10:30:00
2024-03-01 13:30:00 2024-03-01 16:30:00 2024-03-01 19:30:00 2024-03-01 22:30:00
2024-03-02 01:30:00 2024-03-02 04:30:00 2024-03-02 07:30:00 2024-03-02 10:30:00
2024-03-02 13:30:00 2024-03-02 16:30:00 2024-03-02 19:30:00 2024-03-02 22:30:00
2024-03-03 01:30:00 2024-03-03 04:30:00 2024-03-03 07:30:00 2024-03-03 10:30:00
2024-03-03 13:30:00 2024-03-03 16:30:00 2024-03-03 19:30:00 2024-03-03 22:30:00
2024-03-04 01:30:00 2024-03-04 04:30:00 2024-03-04 07:30:00 2024-03-04 10:30:00
2024-03-04 13:30:00 2024-03-04 16:30:00 2024-03-04 19:30:00 2024-03-04 22:30:00
2024-03-05 01:30:00 2024-03-05 04:30:00 2024-03-05 07:30:00 2024-03-05 10:30:00
2024-03-05 13:30:00 2024-03-05 16:30:00 2024-03-05 19:30:00 2024-03-05 22:30:00
2024-03-06 01:30:00 2024-03-06 04:30:00 2024-03-06 07:30:00 2024-03-06 10:30:00
2024-03-06 13:30:00 2024-03-06 16:30:00 2024-03-06 19:30:00 2024-03-06 22:30:00
2024-03-07 01:30:00 2024-03-07 04:30:00 2024-03-07 07:30:00 2024-03-07 10:30:00
2024-03-07 13:30:00 2024-03-07 16:30:00 2024-03-07 19:30:00 2024-03-07 22:30:00
2024-03-08 01:30:00 2024-03-08 04:30:00 2024-03-08 07:30:00 2024-03-08 10:30:00
................................................................................
.....
2024-03-24 13:30:00 2024-03-24 16:30:00 2024-03-24 19:30:00 2024-03-24 22:30:00
2024-03-25 01:30:00 2024-03-25 04:30:00 2024-03-25 07:30:00 2024-03-25 10:30:00
2024-03-25 13:30:00 2024-03-25 16:30:00 2024-03-25 19:30:00 2024-03-25 22:30:00
2024-03-26 01:30:00 2024-03-26 04:30:00 2024-03-26 07:30:00 2024-03-26 10:30:00
2024-03-26 13:30:00 2024-03-26 16:30:00 2024-03-26 19:30:00 2024-03-26 22:30:00
2024-03-27 01:30:00 2024-03-27 04:30:00 2024-03-27 07:30:00 2024-03-27 10:30:00
2024-03-27 13:30:00 2024-03-27 16:30:00 2024-03-27 19:30:00 2024-03-27 22:30:00
2024-03-28 01:30:00 2024-03-28 04:30:00 2024-03-28 07:30:00 2024-03-28 10:30:00
2024-03-28 13:30:00 2024-03-28 16:30:00 2024-03-28 19:30:00 2024-03-28 22:30:00
2024-03-29 01:30:00 2024-03-29 04:30:00 2024-03-29 07:30:00 2024-03-29 10:30:00
2024-03-29 13:30:00 2024-03-29 16:30:00 2024-03-29 19:30:00 2024-03-29 22:30:00
2024-03-30 01:30:00 2024-03-30 04:30:00 2024-03-30 07:30:00 2024-03-30 10:30:00
2024-03-30 13:30:00 2024-03-30 16:30:00 2024-03-30 19:30:00 2024-03-30 22:30:00
2024-03-31 01:30:00 2024-03-31 04:30:00 2024-03-31 07:30:00 2024-03-31 10:30:00
2024-03-31 13:30:00 2024-03-31 16:30:00 2024-03-31 19:30:00 2024-03-31 22:30:00
It seems that the setgrid did not changed the coordinates. I tried to use also remap but I got error message:
cdo remapcon,mygrid_CT-NRT CT-NRT.v2025_mergetime_fixedgrid2.nc CT-NRT.v2025_mergetime_lonlat_file.nc
cdo remapcon (Abort): Unsupported generic coordinates (Variable: calendar_components)!
I attached one CT-NRT.nc file.
Could someone suggest me a solution?
Replies (2)
RE: Issue with converting generic coordinate to lonlat one - Added by Uwe Schulzweida about 1 year ago
The grid is correctly recognized as lonlat. Arrays that are not defined on the lonlat grid must be removed before interpolation. Here are two examples:
cdo remapcon,<targetgrid> -selgridname,lonlat infile outfile
cdo remapcon,<targetgrid> -delname,calendar_components,decimal_date infile outfile
RE: Issue with converting generic coordinate to lonlat one - Added by Karin Meier-Fleischer about 1 year ago
And the axis attribute of the latitude variable is set to "Z" instead of "Y".