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!Environment Canada - Atmospheric Science and Technology License/Disclaimer,
!                     version 3; Last Modified: May 7, 2008.
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!

      SUBROUTINE SETFGEGPS 3,1
#if defined (DOC)
*
***s/r  -SETFGEGPS Sets first-guess error for all GB-GPS ZTD observations
*
*
*Author  : S. Macpherson *ARMA/MSC  December 2004
*
*Revisions:
*
*    -------------------
**    Purpose: Set FGE for all GPS ZTD observations using
*              adjoint of gpsztdop to get Jacobians
*
*Arguments
*     None
*
*
#endif

      IMPLICIT NONE
*implicits
#include "comlun.cdk"
#include "pardim.cdk"
#include "comdim.cdk"
#include "comdimo.cdk"
#include "comgem.cdk"
#include "comcst.cdk"
#include "comphy.cdk"
#include "comoabdy.cdk"
#include "comoahdr.cdk"
#include "comoba.cdk"
#include "commvo.cdk"
#include "commvog.cdk"
#include "cvcord.cdk"
#include "comnumbr.cdk"
#include "comstate.cdk"
#include "comgpsgb.cdk"
*
C
      REAL*8 ZTODEG
      REAL*8 ZLAT
      REAL*8 ZLON
      REAL*8 ZETA(NFLEV)
      REAL*8 ZTT (NFLEV)
      REAL*8 ZHU (NFLEV)
      REAL*8 ZGZ (NFLEV)
      REAL*8 ZTTB (NFLEV)
      REAL*8 ZHUB (NFLEV)
      REAL*8 ZP0
      REAL*8 ZP0B
      REAL*8 ZPT
      REAL*8 ZMT
      REAL*8 ZP0S
c      REAL*8 ZSBLCRIT(2)
      REAL*8 ZTTS(NFLEV), ZHUS(NFLEV), ZGZS(NFLEV)
C
      REAL*8 ZOER, ZINC, ZHX, ZLEV
      REAL*8 ZDZ
      REAL*8 ZHXB, ZVAR
C
      REAL*8 ZJTT (NFLEV)
      REAL*8 ZJHU (NFLEV)
      REAL*8 ZJP0, ZLSUM
C
      INTEGER JF
      INTEGER IBEGIN  , ILAST
      INTEGER IBEGINOB, ILASTOB, JO
      INTEGER IDATYP, ITYP
      INTEGER IDATA   , IDATEND, JDATA
      INTEGER JL, JK
C
      LOGICAL  ASSIM, LLSHIFT, LLOK

      INTEGER NH, NH1
      
C
C     * 1.  Initializations
C     *     ---------------
C
      ZTODEG = 180.0 / RPI
C     *  Depth of PBL in Pa for (1) TT and (2) HU
c      ZSBLCRIT(1) = 5000.0
c      ZSBLCRIT(2) = 5000.0
C
C     *    .   1.1  Eta vector
C     *    .        ----------
C      
      DO JL = 1, NFLEV
         ZETA(JL) = VLEV(JL)
      ENDDO
C
C     Loop over all observation files (all observation types)
C
      DO JF = 1, NFILES
C
C     *  Process only GPS observation files (family = GP)
C
         IF ( CFAMTYP(JF).EQ.'GP' .AND. NBEGINTYP(JF).GT.0 ) THEN
            IBEGIN   = NBEGINTYP(JF)
            ILAST    = NENDTYP  (JF)
            IBEGINOB = MOBDATA(NCMOBS,IBEGIN)
            ILASTOB  = MOBDATA(NCMOBS,ILAST )
C
C     *     Loop over all GPS observations (locations) of the file
C
            DO JO = IBEGINOB, ILASTOB
C     
C     *    .   Process only zenith delay data (codtyp 189 and NEZD)
C
               IDATYP = MOD(MOBHDR(NCMITY,JO),1000)
               IF ( IDATYP .EQ. 189 ) THEN
C
C                 Loop over data in the observations
C
                  IDATA   = MOBHDR(NCMRLN,JO)
                  IDATEND = MOBHDR(NCMNLV,JO) + IDATA - 1
                  ASSIM = .FALSE.
C
C                 Scan for requested assimilations, and count them.
C
                  NH = 0
                  DO JDATA= IDATA, IDATEND
                     ITYP = MOBDATA(NCMVNM,JDATA)
                     LLOK = ( (ITYP .EQ. NEZD) .AND. 
     &                      (MOBDATA(NCMASS,JDATA) .EQ. 1) )
                     IF ( LLOK ) THEN
                        ASSIM = .TRUE.
                        NH = NH + 1
                     ENDIF
                  ENDDO
C
C     *           If assimilations are requested, apply the AD observation operator
C
                  IF (ASSIM) THEN
C     
C     *        LR background profile and background errors at the observation location x :
C
                     ZLAT = ROBHDR(NCMLAT,JO) * ZTODEG
                     ZLON = ROBHDR(NCMLON,JO) * ZTODEG
                     DO JL = 1, NFLEV
                       ZTTB(JL) = GOMTG(JL,JO)
                       ZTT(JL)  = GOMT(JL,JO)
                       ZHUB(JL) = EXP(GOMQG(JL,JO))
                       ZHU(JL)  = GOMQ(JL,JO)
                       ZGZ(JL)  = GOMGZG(JL,JO)
                     ENDDO
                     ZP0B = GOMPSG(1,JO)
                     ZP0  = GOMPS(1,JO)
                     ZPT  = RPPOBS(1,JO)
                     ZMT  = ZGZ(NFLEV)/GRAV
C
C     *        Call AD of ZTD observation operator to get Jacobians dH/dX
C 
C
C
                     NH1 = 0
                     DO JDATA= IDATA, IDATEND
                        ITYP = MOBDATA(NCMVNM,JDATA)
                        IF ( MOBDATA(NCMASS,JDATA).EQ.1 .AND. 
     +                     ITYP.EQ.NEZD ) THEN
                           NH1 = NH1 + 1
C
C     *                    Observation error    SDERR
c                           ZOER = ROBDATA8(NCMOER,JDATA)
C
                           ZHX = 1.0
C
C     *                    Observation height (m)
                           ZLEV = ROBDATA8(NCMPPP,JDATA)
C
                      CALL GPSZTDOPAD(ZLAT,ZLON,ZLEV,ZETA,ZTTB,
     +                  ZHUB,ZP0B,ZPT,ZMT,ZGZ,ZHXB,ZJTT,ZJHU,ZJP0,ZHX)
C
C                          dH/dQ ---> dH/d(lnQ)
                           ZJHU(:) = ZHUB(:)*ZJHU(:)
C
C     *        Compute the background ZTD error (HBHt)
                           ZLSUM = 0.0
                           DO JL = 1, NFLEV
                             ZLSUM = ZLSUM +  (ZJTT(JL)*ZTT(JL))**2 +
     +                               (ZJHU(JL)*ZHU(JL))**2 
                           ENDDO
                           ZLSUM = ZLSUM + (ZJP0*ZP0)**2
                           ROBDATA(NCMFGE,JDATA) = SQRT(ZLSUM)                           
C
                           IF (JO.EQ.IBEGINOB .AND. NH1.LE.3) THEN
                            WRITE(NULOUT,
     +                      '(A11,A9,3(1x,f7.2))')
     +                      'SETFGEGPS: ',CSTNID(JO),ZLAT,ZLON,ZLEV
                            WRITE(NULOUT,*) 'JL JACT JACQ FGE_T FGE_LQ'
                            DO JL = 1, NFLEV
                             WRITE(NULOUT,
     +   '(1X,I2,4(1x,E13.6))') JL,ZJTT(JL),ZJHU(JL)/ZHUB(JL),ZTT(JL), ZHU(JL)                           
                            ENDDO                         
                            WRITE(NULOUT,*) 'JACPS FGE_PS'
                            WRITE(NULOUT,'(2(1x,E13.6))') ZJP0, ZP0
                           ENDIF
C
                        ENDIF
                     ENDDO
                  ENDIF
               ENDIF
            ENDDO

         ENDIF

      ENDDO
C
C      WRITE(NULOUT, *) ' '
C
      RETURN
      END