(1) Outputing radiance diagnostics from WRF-Var

   Run WRF-Var with the following namelist variables in record wrfvar14 in namelist.input

      write_iv_rad_ascii=.true.  ; to write out (observation-background) and other diagnostics
                                 ; information in plain-text files with prefix inv followed by 
                                 ; instrument name and processor id. For example, 
                                 ; inv_noaa-17-amsub.00
      write_oa_rad_ascii=.true.  ; to write out (observation-background), (observation-analysis)
                                 ; and other diagnostics information in plain-text files with 
                                 ; prefix oma followed by instrument name and processor id. 
                                 ; For example, oma_noaa-18-mhs.01

      Each processor writes out information of one instrument in one file
      in the WRF-var working directory

(2) Radiance diagnotics data processing

      A Fortran90 program is used to collect the inv* or oma* files (specified in namelist)
      and write out in netCDF format (one instrument in one file with prefix diags followed 
      by instrument name, analysis date, and suffix .nc)) for easier data viewing, handling 
      and plotting with netCDF utilities and NCL scripts.

(3) Radiance diagnotics plotting

      NCL scripts are used for plotting. The NCL script can be run from a shell script, 
      or run stand-alone with interactive ncl command (need to edit the NCL script and 
      set the plot options. Also the path of advance_cymdh.ncl, a date advancing script
      loaded in the main NCL plotting script, may need to be modified).

Step (2) and (3) can be done by running a single ksh with proper settings (directories,
plotting options, and mapping information). The ksh provided is quite self-explanatory.

#########################################################################
# Script: da_rad_diags.ksh  (radiance diagnostics)
#
# Purpose: run inv*/oma* data processing program (da_rad_diags.f90)
# to generate files in netcdf format and use NCL plotting script
# (plot_rad_diags.ncl and advance_cymdh.ncl) to make plots.
#
# Description:
#
### Data processing:
#
# input files: (1)  namelist.da_rad_diags
#                   &record1
#                    nproc = 16   (the proc numbers WRF-Var used)
#                    instid = 'noaa-17-amsub', 'dmsp-16-ssmis'  (inst names)
#                    file_prefix = "inv"       (either "inv", or "oma")
#                    start_date = '2005082000'
#                    end_date   = '2005083018'
#                    cycle_period  = 6
#                   /
#              (2) inv_* or oma_* from WRF-Var
#                  (note: da_rad_diags.f90 expects the files are in the date directory
#                   in the program working directory, therefore, it's necessary to link
#                   or copy inv_* or oma_* to the required dirctory structure.)
#
### plotting                   
#
# plot_rad_diags.ncl is the main NCL script.
# A date advancing NCL script, advance_cymdh.ncl, is loaded in plot_rad_diags.ncl.