subroutine ld_radlow(wvl, success)
c
c procedure name: 	ld_radlow
c procedure type: 	fortran subroutine
c version date:		27.vi.97
c
c purpose:
c   loads the lookup table requred to obtain the radiance from the 
c   putative cloud optical thickness (or vice versa).
c
c   the lookup table is stored in common block /radlowcom/.
c
c   note that to construct the radiance at a location (for arbitrary rs),
c   the formula is
c
c    i = rad(isza_l, iaz, isat, itcl, ipt) +  
c
c                             rs * tprm(isat,itcl,ipt) * flxd(isza_l,itcl,ipt)
c                             ----------------------------------------------
c                                       1 - rs * sbar(itcl, ipt)
c
c calling parameters:
c   name	type	i/o	units	description
c   --------	----	---	-----	--------------
c   wvl         i4      i       nm      reflectivity channel wavelength
c   success     l       o               flags successful completion.
c
c external routines required:
c   get_lun
c   unget_lun
c
c notes & caveats:
c
c revision history:
c   19.vii.98 introduced use of get_lun/unget_lun, rather than static use of lun (eac)
c   27.vi.97 documentation added (eac).
c
c============================================================================
      implicit none
      integer*4 nsza_p,    naz_p,   nsat_p,   ntcl_p,   npt_p
      parameter(nsza_p=11, naz_p=7, nsat_p=9, ntcl_p=5, npt_p=2)
c     -- calling parameters
      integer*4 wvl
      logical success
c     -- common blocks
      integer*4 nsza_l, naz_l, nsat_l, ntcl_l, npt_l
      real*8 sza_l(0:nsza_p-1), az_l(0:naz_p-1), sat_l(0:nsat_p-1), 
     &       tcl_l(0:ntcl_p-1), pt_l(0:npt_p-1),
     &  rad_l(0:nsza_p-1, 0:naz_p-1, 0:nsat_p-1, 0:ntcl_p-1, 0:npt_p-1),
     &  tprm_l(0:nsat_p-1, 0:ntcl_p-1, 0:npt_p-1),
     &  flxd_l(0:nsza_p-1, 0:ntcl_p-1, 0:npt_p-1),
     &  sbar_l(0:ntcl_p-1, 0:npt_p-1)
      common /radlowcom/ sza_l, az_l, sat_l, tcl_l, pt_l, 
     &                   rad_l, flxd_l, tprm_l, sbar_l, 
     &                   nsza_l, naz_l, nsat_l, ntcl_l, npt_l
      save /radlowcom/
c     local variables
      integer*2 nsza_i, naz_i, nsat_i, ntcl_i, npt_i
      real*4 sza_i(0:nsza_p-1), az_i(0:naz_p-1), sat_i(0:nsat_p-1), 
     &       tcl_i(0:ntcl_p-1), pt_i(0:npt_p-1),
     &  rad_i(0:nsza_p-1, 0:naz_p-1, 0:nsat_p-1, 0:ntcl_p-1, 0:npt_p-1),
     &  tprm_i(0:nsat_p-1, 0:ntcl_p-1, 0:npt_p-1),
     &  flxd_i(0:nsza_p-1, 0:ntcl_p-1, 0:npt_p-1),
     &  sbar_i(0:ntcl_p-1, 0:npt_p-1)
      integer*4 lun
      integer*4 i, isat, isza, itcl, iaz, ipt
      character*13 filename /'radlow000.bin'/
      write(filename(7:9),'(i3.3)') wvl
      call get_lun(lun)
      open(unit=lun,file=filename, form='unformatted', status='old',
     $     err=900)
      read(lun) nsza_i  
      if (nsza_i .ne. nsza_p) goto 901
      read(lun) sza_i
      read(lun) naz_i   
      if (naz_i .ne. naz_p) goto 902
      read(lun) az_i 
      read(lun) nsat_i  
      if (nsat_i .ne. nsat_p) goto 903
      read(lun) sat_i
      read(lun) ntcl_i  
      if (ntcl_i .ne. ntcl_p) goto 904
      read(lun) tcl_i
      read(lun) npt_i   
      if (npt_i .ne. npt_p) goto 905
      read(lun) pt_i 
      read(lun) rad_i
      read(lun) tprm_i
      read(lun) flxd_i
      read(lun) sbar_i
      close(lun)
      call unget_lun(lun)
      nsza_l= nsza_i
      do i= 0, nsza_l-1
         sza_l(i)= sza_i(i)
      enddo
      naz_l=  naz_i
      do i= 0, naz_l-1
        az_l(i)= az_i(i)
      en ddo
      nsat_l= nsat_i
      do i= 0, nsat_l-1
         sat_l(i)= sat_i(i)
      enddo
      ntcl_l= ntcl_i
      do i= 0, ntcl_l-1
        tcl_l(i)= tcl_i(i)
      end do
      npt_l=  npt_i
      do i= 0, npt_l-1
         pt_l(i)= pt_i(i)
      enddo
      do isza=0, nsza_p-1 
         do iaz= 0, naz_p-1
            do isat= 0, nsat_p-1
               do itcl= 0, ntcl_p-1
                  do ipt= 0, npt_p-1
                     rad_l(isza, iaz, isat, itcl, ipt)= 
     &                  rad_i(isza, iaz, isat, itcl, ipt)
                  enddo
               enddo
            enddo
         enddo
      enddo
      do isat= 0, nsat_p-1
         do itcl= 0, ntcl_p-1
            do ipt= 0, npt_p-1
               tprm_l(isat, itcl, ipt)= tprm_i(isat, itcl, ipt)
            enddo
         enddo
      enddo
      do isza= 0, nsza_p-1
         do itcl= 0, ntcl_p-1
            do ipt= 0, npt_p-1
               flxd_l(isza, itcl, ipt)= flxd_i(isza, itcl, ipt)
            enddo
         enddo
      enddo
      do itcl= 0, ntcl_p-1
         do ipt= 0, npt_p-1
            sbar_l(itcl, ipt)= sbar_i(itcl, ipt)
         enddo
      enddo
      success=.true.
      return
  900 continue
      write(6,90) filename
      goto 999
  901 continue
      write(6,91) filename,  'sza', nsza_p, nsza_i
      goto 999
  902 continue
      write(6,91) filename,  'az', naz_p, naz_i
      goto 999
  903 continue
      write(6,91) filename,  'sat', nsat_p, nsat_i
      goto 999
  904 continue
      write(6,91) filename,  'tcl', ntcl_p, ntcl_i
      goto 999
  905 continue
      write(6,91) filename,  'pt', npt_p, npt_i
      goto 999
  999 continue
      success=.false.
      return
   90 format(' !!! ld_radlow !!! could not open the file ',a20)
   91 format(' !!! ld_radlow !!! encountered unexpected value in ',
     &  ' file ',a20/
     & t20,'number of values for ',a4,' : expected=',i3,', found=',
     &  i3)
      end