[netcdfgroup] How can i read netcdf file of station data

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: [netcdfgroup] How can i read netcdf file of station data
• From: Rabah Hachelaf <r.hachelaf@xxxxxxxxx>
• Date: Thu, 12 Sep 2013 17:29:09 -0500

Hello all ,

Please can any one have experience with netcdf data with irregular grid.
my data file is taken from NCEP ADP Global Upper Air and Surface Weather
Observations (PREPBUFR format)

So i need to extract data in a ASCII file like this :

STATION_ID   LAT  LON  OBS_VAL ...
70585             45.5     60.5    1005.5    .....


the header information is :

[hachelaf@skynet1 test]$ ncdump -h gdas.44512.2010040100.nc
netcdf gdas.44512.2010040100 {
dimensions:
        mxstr = 16 ;
        hdr_arr_len = 3 ;
        obs_arr_len = 5 ;
        nobs = UNLIMITED ; // (98012 currently)
        nhdr = 30766 ;
variables:
        char obs_qty(nobs, mxstr) ;
                obs_qty:long_name = "quality flag" ;
        float obs_arr(nobs, obs_arr_len) ;
                obs_arr:long_name = "array of observation values" ;
                obs_arr:_fill_value = -9999.f ;
                obs_arr:columns = "hdr_id gc lvl hgt ob" ;
                obs_arr:hdr_id_long_name = "index of matching header data" ;
                obs_arr:gc_long_name = "grib code corresponding to the
observation type" ;
                obs_arr:lvl_long_name = "pressure level (hPa) or
accumulation interval (sec)" ;
                obs_arr:hgt_long_name = "height in meters above sea level
(msl)" ;
                obs_arr:ob_long_name = "observation value" ;
        char hdr_typ(nhdr, mxstr) ;
                hdr_typ:long_name = "message type" ;
        char hdr_sid(nhdr, mxstr) ;
                hdr_sid:long_name = "station identification" ;
        char hdr_vld(nhdr, mxstr) ;
                hdr_vld:long_name = "valid time" ;
                hdr_vld:units = "YYYYMMDD_HHMMSS" ;
        float hdr_arr(nhdr, hdr_arr_len) ;
                hdr_arr:long_name = "array of observation station header
values" ;
                hdr_arr:_fill_value = -9999.f ;
                hdr_arr:columns = "lat lon elv" ;
                hdr_arr:lat_long_name = "latitude" ;
                hdr_arr:lat_units = "degrees_north" ;
                hdr_arr:lon_long_name = "longitude" ;
                hdr_arr:lon_units = "degrees_east" ;
                hdr_arr:elv_long_name = "elevation" ;
                hdr_arr:elv_units = "meters above sea level (msl)" ;

// global attributes:
                :FileOrigins = "File
/glade/p/rda/transfer/dsrqst/RABAH44512/gdas.44512.2010040100.nc generated
20130912_180331 UTC on host geyser01 by the MET pb2nc tool" ;
                :MET_version = "V4.1" ;
                :MET_tool = "pb2nc"

-- 
------------------------------
Cordialement,
Best regards,
Rabah Hachelaf