function nws_metar2latest
% nws_metar2latest
%
% Last modified:  Time-stamp: <2005-01-19 17:05:54 haines>
% 
% Abstract: Get latest NWS METAR data, parse latest 48 hour obs into netCDF
%   files as part of the SEACOOS merged product effort. 
%
% Usage: >> nws_metar2latest
%

% 
% Author: Sara Haines, Sept 18, 2003

% Processing:
%   In general, for each station want to produce a file of last 48
%   hours of obs. This file is a netCDF file with agreed upon conventions (Sep
%   12, 2003 -- see Celoxis Metadata Project,
%   http://aslnx1.oasis.unc.edu:8080/psa/servlet/project?bxn=cview&p_p_id=2139)
%   for metadata content, structure, format, and naming conventions.
%   
%   Uses the monthly raw METAR files archived for each station.
%   
  
  raw_dir = '/seacoos/data/nws_metar/raw_data';
  out_nc_v20_dir = '/seacoos/data/nws_metar/proc_data/latest_v2.0';
  station_info_file = '/opt/local/seacoos/bin/stations_seacoos.txt';
  
  % get the current time (GMT), as processing time reference point especially
  % for auto mode.  This unix call is required to get date in GMT since MATLAB
  % has no function to get this without hardcoding it.

  [e,z]=unix(['date -u ''+%d-%b-%Y %H:%M:%S''']);
  current_time_dn = datenum(z(1:end-1));

  % show time of run for the log files
  fprintf(2,'\nStart time: %s\n', datestr(current_time_dn, 'dd-mmm-yyyy HH:MM:SS'));
  fprintf(2,['Processing latest 48 hour data from all airport stations in' ...
	     ' SEACOOS region ...\n']);
    
  % use current time (current_time_dn) to set month and previous month strings
  % month_str = datestr(current_time_dn, 'mmmyy');  % e.g. Apr03
  
  month_str = [datestr(current_time_dn, 'yyyy') '_' ...
              datestr(current_time_dn, 'mm')];    % e.g. 2003_04
  
  % determine previous month string from current.  Need this to make the
  % month transition.
 
  dv = datevec([month_str(6:7) '/01/' month_str(1:4)]);  % make it 04/01/2000]
  prev_month_str = [datestr(datenum(dv(1),dv(2),-1,0,0,0),'yyyy') '_' ...
                   datestr(datenum(dv(1),dv(2),-1,0,0,0),'mm')]; % e.g. 2003_04

  % directory of stations
  x = dir([raw_dir '/*']);
    
  % remove any parent or current directories or not a directory
  x = struct2cell(x);
  x = x(1,:);
  whichnot =  find(strcmp(x,'.')|strcmp(x,'..'));
  x(whichnot)=[];
  [n, numstations] = size(x);
  
  info.current_time_dn = current_time_dn;
  info.month_str = month_str;
  info.prev_month_str = prev_month_str;
  info.raw_dir = raw_dir;
  info.out_nc_v20_dir = out_nc_v20_dir;
  
  
  % read stations_seacoos.txt and find index of station id, name,
  % state/country, lat, lon, elev
  all_lines = textread(station_info_file,'%s','delimiter','\n','whitespace','');


% for each station
  for i=1:numstations
    
    info.platform_name = upper(char(x(i)));
    info.package_name = 'metar';
    
    fprintf(2, ['... %s\n'], char(x(i)));
	  
    % find which line of station data and extract info
    %  e.g. which_line = find(strncmp(all_lines, 'KRDU', 4)); 
    which_line = find(strncmp(all_lines, info.platform_name, 4)); 
    station_str = char(all_lines(which_line)); 
    [STATION_ID, NAME, LATdeg, LATmin, LAThem, LONdeg, LONmin, LONhem, ELEV] = ...
	strread(station_str, '%4c %19c %d %d%c %d %d%c %d%*[^\n]');
    
    % set metadata info to be written in netcdf files and used in some calculations
    info.location_name = NAME;
    info.location_elev = ELEV;
    if regexp(LAThem, 'S|s')
      info.location_lat = -1*(LATdeg+(LATmin/60));
    else % regexp(LAThem, 'N|n')
      info.location_lat = LATdeg+(LATmin/60);
    end

    if regexp(LONhem, 'W|w')
      info.location_lon = -1*(LONdeg+(LONmin/60));
    else % regexp(LONhem, 'E|e)
      info.location_lon = LONdeg+(LONmin/60);
    end

    info.rawdirname = [info.raw_dir '/' char(x(i))];
    get_latest_metar(info);
    
  end