CDO

Hi. This question gets asked a lot. Have you searched the forums for possible answers?

Hello Brendan,

Yes, I found many subjects on the forum but no answer, nor in the online documentation. Particulary how to correctly create the gridfile description.

thanks,

Hi S,

choosing the PROJ.4 settings from the description of the EPSG:2752 projection https://epsg.io/27572 and modifying the grid description file I got an netCDF file which seems to be close but not correct.

By the way rows = y and cols = x, so your xsize and ysize had to be exchanged.
You have to take care about the settings by yourself.

gridfile.txt:

gridtype = projection
gridsize = 1265851
xsize    = 1171
ysize    = 1081
xfirst   = 39500
xinc     = 1000
xunits   = "m" 
yfirst   = 1604500
yinc     = 1000
yunits   = "m" 
grid_mapping = crs
grid_mapping_name = lambert_conformal_conic
proj_params = "+proj=lcc +lat_1=46.8 +lat_0=46.8 +lon_0=0 +k_0=0.99987742 +x_0=600000 +y_0=2200000 +a=6378249.2 +b=6356515 +towgs84=-168,-60,320,0,0,0,0 +pm=paris +units=m +no_defs" 

Convert to projected grid in netCDF format:

cdo -f nc -settaxis,2020-04-01,00:00:00,1day -setctomiss,-9999.0 -setname,prtot -input,gridfile.txt out.nc < Test_pr_2.asc

Remap to regular lonlat:

cdo -remapbil,r3600x1800 out.nc out_remapped.nc

Now, its on you to find the correct settings.

-Karin

Hello Karin,

Many thanks for the gridfile description. yfirst and yinc parameters have to be changed (yfirst=ymax, yinc=-yinc). It's ok now with this configuration.