!This program converts NCDC wind data files (*.wnd2):
!to a format that can be read by the WERU wind_mdb program.

!Referring to NCDC document 'Data documentation for data set TD-6421'
!(TD-6421.doc), p 9-11 (section 4.3).

!Data are not written out if missing (dr < 0 and/or sp < 0).
!Data are not written out if wrong (flags Q , S).

!Wind speed adjusted to 10 m height (sp10) is used. 
!If snow on the ground > 10 cm, sp_surf is used. 
!Wind speed is converted to m/s.

!Examples: 
!ncdc2weru < 690070.wnd2 > 690070.org
!ncdc2weru -b1980 -e1989 < 690070.wnd2 > 690070.org


      integer sp,dr, sp10, sp_surf, year, month, day, hour, count
      integer begin_year, end_year
      character *1 s,q,z 
      character*25 argv  
      real dr_real  !want to write wind direction as a real

      begin_year = 1800
      end_year = 2100
      if (iargc() .gt. 0) then
	do 09 i = 1, iargc()
          call getarg(i,argv) 

          if (argv(1:1) .ne. '-') then  !make sure all options start with '-'
	    write(*,*) trim(argv), ': Option ignored, it should start ',&
     &                 'with a dash (-)'
            goto 09   !Go get next arg    
          endif

           !command line help prompt
          if ((argv(2:2).eq.'?').or.(argv(2:2).eq.'h')) then
            write(*,*) 'Valid command line options:'
            write(*,*) '-? or -h Display this help screen'
            write(*,*) '-b# begin year, e.g. -b1980'
            write(*,*) '-e# end year, e.g. -e1989)'

            stop

          else if (argv(2:2) == 'b') then
            read(argv(3:),*) begin_year            

          else if (argv(2:2) == 'e') then
            read(argv(3:),*) end_year            

          end if
09      continue
      endif


      do while (2 > 1) !only leave this loop when eof.
        read(*,33,end=300)wmo6,year,month,day,hour,sp,dr,s,q,sp10,an,z, &
     &                    sp_surf
33      format(a6, i4,3i2.2,i4,1x,i3,2a1,i4,1x,f4.1,a1,i4)

        if (year >= begin_year .and. year <= end_year) then
          if (dr < 0) go to 100 !missing data
          if (sp < 0) go to 100 !missing data
          if (q .eq. 'Q') go to 100 !data wrong
          if (q .eq. 'S') go to 100 !data wrong 
  
          if (z .eq. '2') sp10 = sp_surf !use snow adjusted wind speed
          sp10mps = sp10/10.0 !wind speed in m/s
  
          dr_real = dr
          write(*,34) year, month, day, hour, dr_real, sp10mps
34        format(x, 4i4, 2f6.1)
        end if
100     continue
      end do
300   end