obs values after asciitonc

[Deba57]

Software Version

5.0.1

Text

Hi,
I am using asciitonc metplus conf file to convert input obs into netcdf file. While looking into output netcdf file, I am seeing lat, lon dimension is different than number of observation. How to line up the coordinates for each of the obs values? Is that there is some kind of cross referencing in the netcdf output, such as site ID arrays. Attached is conf file and output netcdf that is generated. Any help is appreciated on this.
ncdump on output shows this :
dimensions:
mxstr = 16 ;
mxstr2 = 40 ;
mxstr3 = 80 ;
nhdr = 2082 ;
nobs = 4026 ;
nhdr_typ = 1 ;
nhdr_sid = 2082 ;
nhdr_vld = 1 ;
nobs_qty = 1 ;
obs_var_num = 6 ;

Asciitonc_AirnowPM25.conf.txt
Airnow_HrlyPM25_2026071718.nc.txt

[hertneky]

Hi,

I see you are struggling with interpreting the NetCDF output from ASCII2NC. It can be a bit tricky if you are not used to it. The descriptions of the NetCDF dimensions and variables can be found here, which has the same format as the PB2NC tool output.

For your output, I see that there is just a single obs type and valid time for several stations (2082). I see that the number of latitudes an longitudes matches the number of stations in your case, which makes sense. Since there can be multiple variables stored for each station, the number of observations is larger. See obs_var for the list of possible variables and obs_vid for the index of the obs_var for each observations value. There is also the obs_hid, which lists the index of the header variables, including lat/lon/etc for each observation.

Additionally, if you wish to interrogate the output, there is a Python utility script that will read the MET NetCDF file and dump out the contents into the more easily readable 11-column format used as input for ASCII2NC.