*-- Author : Stephen Burke
      SUBROUTINE FKLSSM(Z,DZ,SVEC,CVEC,SPRO,QGAIN,QPRO,SSMT,CSMT,IERR)
*-----------------------------------------Updates 07/02/92-------                                             
**: FKLSSM 30205.SB. Remove unused FKECODE sequence.                                                          
*-----------------------------------------Updates----------------                                             
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*                                                                    *                                        
* Simple Kalman Smoothing                                            *                                        
*                                                                    *                                        
* ERROR CONDITIONS;                                                  *                                        
*       IERR =   0 ; normal termination                              *                                        
*       IERR = 116 ; x, y or theta has silly value                   *                                        
*       IERR =  17 ; tan(theta) > 1 (warning)                        *                                        
*                                                                    *                                        
**********************************************************************                                        
**********************************************************************                                        
* Adjust the old smoothed vector to allow for MS ...                                                          
      CALL FKADJ(SVEC,SPRO,QGAIN,SADJ)
      CALL FKNORM(SADJ,IFAIL)
      IF (IFAIL.NE.0) CALL FKERR(IUTIL,IROUT,IFAIL/100,IFAIL,IERR)
* ... translate to the new position ...                                                                       
      CALL FKTRAN(DZ,Z,SADJ,SSMT,DINV)
      CALL FKNORM(SSMT,IFAIL)
      IF (IFAIL.NE.0) CALL FKERR(IUTIL,IROUT,IFAIL/100,IFAIL,IERR)
* ... and calculate the new covariance                                                                        
      CALL FKDMQD(DINV,QGAIN,AGAIN)
      CALL FKMXM(CVEC,AGAIN,CSMT)
      CALL FKDQA(DINV,QPRO,AGAIN,CSMT)
*