Hello, I have a question about altering the variable structure of an existing
netcdf file.
Due to a change in specs, our file structure needs to remove one of the
dimensions of a variable. Currently, the variable 'lon' is 3d, and we now need
to remove the 'time' dimension.
we need to change lon(time,nj,ni) to lon(nj,ni), where 'time' was/is always =
1, while the other 2 dimensions vary from file to file.
I hoped that it was possible write a c program to just read in 'lon', delete it
from the file, and then declare 'lon' with the new dimensions and write it out.
I have been informed that this is not possible, and that my only option is to
read all the data from all variables and globals, and reconstruct the entire
file.
Can someone confirm if this is indeed necessary??
Thankyou for your help.
George
A portion of the current file structure is shown here --
netcdf
20090701-ABOM-L2P_GHRSST-SSTsubskin-AVHRR17_D-20090701T1104Z_Asc-v02.0-fv01.0 {
dimensions:
ni = 2048 ;
nj = 7457 ;
time = 1 ;
variables:
float lon(time, nj, ni) ;
lon:long_name = "longitude" ;
lon:units = "degrees_east" ;
lon:_FillValue = -999.f ;
lon:valid_min = -180.f ;
lon:valid_max = 360.f ;
lon:coordinates = "lon lat" ;
float lat(time, nj, ni) ;
lat:long_name = "latitude" ;
lat:units = "degrees_north" ;
lat:_FillValue = -999.f ;
lat:valid_min = -90.f ;
lat:valid_max = 90.f ;
lat:coordinates = "lon lat" ;
int time(time) ;
time:long_name = "reference time of sst file" ;
time:units = "seconds since 1981-01-01 00:00:00" ;
short sea_surface_temperature(time, nj, ni) ;
sea_surface_temperature:long_name = "sea surface subskin
temperature" ;
sea_surface_temperature:units = "kelvin" ;
sea_surface_temperature:_FillValue = -32768s ;
sea_surface_temperature:add_offset = 273.15 ;
sea_surface_temperature:scale_factor = 0.01 ;
sea_surface_temperature:valid_min = -5000s ;
sea_surface_temperature:valid_max = 5000s ;
sea_surface_temperature:coordinates = "lon lat" ;
sea_surface_temperature:source = "AVHRR17_D" ;
// global attributes:
:Conventions = "CF-1.4" ;
:title = "AUS HRPT AVHRR SST Retrieval from NOAA-17" ;
:DSD_entry_id = "AVHRR17_D-ABOM-L2P" ;
