subroutine randhbht1 1
#if defined (DOC)
*
***s/r randhbht1  - output random sample of background error in obs space in posv file
*
*Author  : M. Buehner *ARMA/MSC  March 2005
*Revision: S. Pellerin ARMA, January 2009
*          - Call to oda subroutines (sqrtB, L and H)
*          Y. Yang ARQI, Jan 2010
*          - Switched the order of the include sequence of 'comnumbr.cdk' and 
*            'cvcord.cdk', 'comstato.cdk' due to dependencies
*
-------------------
**    Purpose:   *
*     .          *
*     .          *
*     .          *
*     .          *
*
*Arguments
*    -NONE-
#endif
      IMPLICIT NONE
*implicits
#include "comct0.cdk"
#include "pardim.cdk"
#include "comdim.cdk"
#include "com1obs.cdk"
#include "comlun.cdk"
#include "comgem.cdk"
#include "comdimo.cdk"
#include "commvo.cdk"
#include "commvohr.cdk"
#include "commvog.cdk"
#include "comnumbr.cdk"
#include "comoabdy.cdk"
#include "comoahdr.cdk"
#include "comoba.cdk"
#include "comvarqc.cdk"
#include "comcva.cdk"
#include "cparbrp.cdk"
#include "cominterp.cdk"
#include "comcst.cdk"
#include "comrand.cdk"
#include "localpost.cdk"
#include "comgdpar.cdk"
#include "rpnstd.cdk"
#include "comgd0.cdk"
#include "comsp.cdk"
#include "comspg.cdk"
#include "compost.cdk"
#include "comfilt.cdk"
#include "comleg.cdk"
#include "comstato.cdk"
#include "compstat.cdk"
#include "cvcord.cdk"
c
      integer jj,jdata
      real*8 gasdev
      real*8 zcmaoma(ndata)
      logical lexist
      external gasdev
c
      call printrev("SUBROUTINE randhbht1 :",22)
c
c initialize random number generator seed
c
      inquire(file='randnum.dat',exist=lexist)
      if(lexist) then
        open(unit=39,form='unformatted',file='randnum.dat')
        read(39) (rrand(jj),jj=1,97)
        read(39) ix1,ix2,ix3,iff
        close(39)
        write(nulout,*) 'READING IN RANDNUM'
      else
        write(nulout,*) 'RANDNUM FILE DOES NOT EXIST'
      endif
c
c Save contents of CMA (observed values)
c
      do jdata = 1, ndata
        zcmaoma(jdata)=robdata8(ncmoma,jdata)
        robdata8(ncmoma,jdata)=-888.0
      enddo
c
c compute HBHT realization in obs space
c
      write(nulout,*) '******************'
      write(nulout,*) 'COMPUTING REALIZATION OF BG ERROR IN OBS SPACE'
      do jj=1,nvadim
        vazx(jj)=gasdev(1)
      enddo

      call oda_sqrtB(vazx,nvadim)
      
      call oda_L

      call oda_H ! Compute Hdx and store the results in ncmoma
c
      do jdata = 1, ndata
        robdata(ncmfge,jdata)=robdata8(ncmoma,jdata)
        robdata8(ncmoma,jdata)=zcmaoma(jdata)
      enddo
c
c set starting point back to zero for minimization
c
      do jj=1,nvadim
        vazx(jj)=0.0d0
      enddo
c 
c writing out random number generator seed
c
      open(unit=39,form='unformatted',file='randnum.dat',STATUS='REPLACE')
      write(39) (rrand(jj),jj=1,97)
      write(39) ix1,ix2,ix3,iff
      close(39)
c
      write(nulout,*) 'DONE COMPUTING REALIZATION OF BG ERROR IN OBS SPACE'
      write(nulout,*) '******************'
c
      return
      end