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Input and Output Files

Most WXP programs will require an data file to process.  WXP can process many different types of files and plot information based on their content.  Because of this, programs are generally isolated to a specific type of file rather than one generic program to process every file type.

File Paths

The location of data files are specified by a set of resources called path resources.  These specify directories where data files are located and where generated data files are to be put.  By default, all files go in the local directory but this is often not used since most files will be saved in a directory on a server.   WXP provides the user with the following path resources:

  • file_path - Specifies location of database files.
  • data_path - Specifies location of data files produced by the WXP and LDM ingestors including WMO, HDS and McIDAS data files.
  • con_path - Specifies location of converted data files produced by WXP decoders including WXP and netCDF file types.
  • grid_path - Specifies location of grid files produced by WXP gridding programs.
  • raw_path - Specifies location of raw files produced by WXP plotting programs.
  • image_path - Specifies location of image files produced by WXP graphics programs.

Ingest Programs

The ingest program whether it be the WXP ingest program or the LDM, will produce several types of files based on the content of the file.  This includes surface, upper air, radar, NIDS, GRIB and text data files.  

The ingestor has a setup file which defines which data types and products are to be saved as well as defining the file name convention that these files will have.  The setup files are either ingest.bul for the WXP ingestor or the pqact.conf file for the LDM.  For example, textual forecasts may go into a forecast file based on the date and the have a file extension describing the type of data in that file:

   F[^OT]         >>   %D/%y%m%d%6h_for.wmo  %D/%y%m%d%6h_for.hdr

This will put all the forecast products for 6 hours into a file with a for.wmo extension.  The %y%m%d%h are used to create a filename based on the current year, month, day and hour. The final keyword is %D, which is the value of the data_path resource. This is where all ingested data goes.  Finally, a header file will be created so quick searching of data can be done.

Decoder Programs

Often it is necessary to decode the ingested data files for easier use by the WXP analysis programs.  The decoders rely on a name convention file to define both the input file name and to be used in creating the output file name.  Each type of data has a tag that is used to find the naming convention.  For example, when converting surface data using the sacvt program, the input tag is sfc_dat and the output tag is sfc_cvt.  These will then be crossed referenced in the name convention file:

   sfc_dat       %D/%y%m%d%h_sao.wmo
   sfc_cvt       %C/%y%m%d%h_sao.wxp

Similar to the ingest setup file, the name convention file uses the same nomenclature for naming its files.  In this case, the input to the decoder is from the ingested data files in the data_path directory.  The output of the decoder will go into a file in the con_path directory.  These path resources can be changed on the command line. Also, the tags themselves can be changed using the in_file and out_file resource.

The out_file resource can also be used to specify the type of decoded output file such as ASCII (wxp) or netCDF (cdf).  When specifying a file type, the type is appended to the tag: sfc_cvt_wxp and  sfc_cvt_cdf which can be used to denote specific file name conventions for each file type:

   sfc_cvt_wxp     %C/%y%m%d%h_sao.wxp
   sfc_cvt_cdf     %C/%y%m%d%h_sao.nc

Analysis Programs

These programs will either access data from the decoders or from the ingested data. Similar to the decoders, these programs use the name convention file to determine input and output naming conventions.   The name convention is also used in providing a list of available files for use at the file name prompt.

   List of available files:

   Enter the surface filename: 96112206

The user may wish to select the filename directly from the list or use the current resource to specify a current or latest available file.

These analysis programs often have optional output files that can be created by specifying the out_file resource.  In this case, the out_file resource specifies the type of output file and can be used to specify the output name convention tag.

   sfc_grd      %G/%v_%m%d%h.grd
   sfc_raw      %R/%v_%m%d%h.raw

In this case, special wildcard characters are set to specify internal parameters such as plot variable, vertical level and forecast time.

The contouring (contour) and raw file plotting programs (mapplt and grid) can then use these files.  Here is a list of file name tags:

Filename Tags
Data Type Ingested Decoded Decoded
Grid Grid
Surface sfc_dat sfc_cvt sfc_cvt_cdf sfc_cvt_wxp sfc_grd sfc_grd_cdf sfc_grd_wxp sfc_raw
Synoptic syn_dat syn_cvt syn_cvt_cdf syn_cvt_wxp        
Upper Air upa_dat upa_cvt upa_cvt_cdf upa_cvt_wxp upa_grd upa_grd_cdf upa_cdf_wxp upa_raw
Radar (MDR) rad_dat rad_cvt rad_cvt_cdf rad_cvt_wxp        
Radar (RCM) rcm_dat rcm_cvt   rad_cvt_wxp        
MOS mos_dat       mos_grd mos_grd_cdf mos_grd_wxp mos_raw
MOS NGM* mos_ngm_dat              
MOS NGM UA* mos_ngmu_dat              
MOS ETA UA* mos_etau_dat              
MOS MRFX* mos_mrfx_dat              
Satellite VIS sat_vis              
Satellite IR sat_ir              
Satellite WV sat_wv              
Profiler prf_dat              
Fronts frt_dat              
Watches wat_dat              
Tropical trp_dat              
NLDN nldn              
GRIB** grib       grd_grd grd_cdf grd_wxp  

* The MOS tags are not set.  Only the strings "ngm", "ngm_ua", "eta_ua", "mrfx" need to appear in the tag for the program to recognize the type of file.
** The GRIB data is defined through a model lookup table.

Name Conventions

The standard naming conventions involve the date and time of the file plus an extension that is based on the file type. The three basic naming conventions are:

  • hhmmddyy.eee (hmdy)
  • yymmddhh.eee (ymdh)
  • yymmddhh_eee.ttt (ymdh_t)

where yy is the last two digits of the year, mm is month of the year, dd is the day of the month and hh is the hour in Universal Time (GMT or Z). Also, the eee is the file extension describing the content of the file and with the ymdh_t naming convention, there is a ttt extension which describes the format of the data.   Typical data types and associated file extensions are as follows:

Raw WMO Data Files eee eee.ttt
Raw surface data files sao sao.wmo
Raw synoptic air data files syn syn.wmo
Raw upper air data files upa upa.wmo
Raw MDR radar data files rad rad.wmo
Raw RCM radar data files rcm rcm.wmo
Raw MOS data files mod mod.wmo
Raw forecast data files for for.wmo
Raw severe data files sev sev.wmo
Raw climate data files cli cli.wmo
Raw weather summary files sum sum.wmo
Raw front analysis files frt frt.wmo
Raw weather watch files wws wws.wmo
McIDAS Data Files eee eee.ttt
East Visible satellite files sve sve.mca
East Infrared satellite files sie sie.mca
East Water vapor satellite files swe swe.mca
West Visible satellite files svw svw.mca
West Infrared satellite files siw siw.mca
West Water vapor satellite files sww sww.mca
Floater sector satellite files sfl sfl.mca
Profiler data files prf prf.cdf
WXP ASCII Converted Data Files eee eee.ttt
Converted surface data files cvt sao.wxp
Converted synoptic data files cvt syn.wxp
Converted upper air data files uac upa.wxp
Converted MDR radar data files sdc rad.wxp
Converted RCM radar data files rct rcm.wxp
netCDF Converted Data Files eee eee.ttt
Converted surface data files cvt sao.cdf
Converted synoptic data files cvt syn.cdf
Converted upper air data files uac upa.cdf
Converted MDR radar data files sdc rad.cdf
HDS Data Files eee eee.ttt
NGM model gbn ngm.grb
ETA model gbm eta.grb
AVN model grid 37 gmi avn0e.grb
AVN model grid 38 gmj avn1e.grb
AVN model grid 39 gmk avn1w.grb
AVN model grid 40 gml avn0w.grb
AVN model grid 41 gmm avs0e.grb
AVN model grid 42 gmn avs1e.grb
AVN model grid 43 gmo avs1w.grb
AVN model grid 44 gmp avs0w.grb
MRF model grid 25 gm5 mrn.grb
MRF model grid 26 gm6 mrs.grb
ECMWF model all grids gbe ecf.grb
SWW model all grids gbs sww.grb
SST analysis gbt sst.grb
Snow Cover Analysis gbc sca.grb
Profiler data prf prf.brf
AIREP data air air.brf
Tropical data   trp trp.wmo

The actual naming conventions are defined in the name convention file.  This is setup by the system administrator.  

in_file and out_file Resources

These resources can be used to specify the tags and the resulting file name conventions used in the program.  Each program has default tags compiled into the program but they can be overridden on the command line:

   -if=sfc_dat -of=sfc_cvt

The resource can specify a whole file name convention string instead of a tag:


or specific files


For further information about WXP, email technical-support@weather.unisys.com
Last updated by Dan Vietor on July 21, 1998