CDO

Good evening,
in order to use the "remapbil" command, the grid that I use should be without missing values of longitude and latitude in the whole grid.
The problem is that i have a temperature map shaped as a region (Lombardia, Italy) and not a perfect square or rectangle, that's why if i follow this grid below, the remap doesn't work.
"
gridtype = lonlat
gridsize = 1148
xsize = 41
ysize = 28
xname = x
xlongname = "longitude"
xunits = "degrees_east"
yname = y
ylongname = "latitude"
yunits = "degrees_north"
xfirst = 8.48826
xinc = 0.0715
yfirst = 44.63501
yinc = 0.0715
"

Is there any way to put the missing lon/lat values or to modify this grid above in order to include only the cells whit values?

Thanks a lot,
Gabriele