var/da/da_varbc/da_varbc_tl.inc

   1   subroutine da_varbc_tl (cv_size, cv, iv, y)
   2
   3    !---------------------------------------------------------------------------
   4    !  PURPOSE: Apply bias correction to radiance innovations.
   5    !
   6    !  METHOD: delta_d    = y - delta_bc
   7    !          y = H (delta_x)
   8    !          delta_bc   = SUM( delta_beta_i Pred_i )
   9    !                       i
  10    !          delta_beta = VarBC parameters
  11    !          Pred = Bias predictors
  12    !
  13    !  Called from da_transform_vtoy
  14    !
  15    !  HISTORY: 10/27/2007 - Creation                     Tom Auligne
  16    !---------------------------------------------------------------------------
  17
  18    implicit none
  19
  20    integer, intent(in)           :: cv_size         ! Size of cv array.
  21    real, intent(in)              :: cv(1:cv_size)   ! control variables.
  22    type (iv_type), intent(in)    :: iv              ! O-B structure.
  23    type (y_type), intent(inout)  :: y               ! y = h (xa)
  24
  25    integer              :: inst, i, k, num_rad, n, npred
  26    real, allocatable    :: varbc_param_tl(:)
  27
  28    if (trace_use) call da_trace_entry("da_varbc_tl")
  29
  30       do inst = 1, iv%num_inst                 ! loop for sensor
  31          num_rad = iv%instid(inst)%num_rad
  32          if (num_rad < 1) cycle
  33
  34          allocate(varbc_param_tl(iv%instid(inst)%varbc_info%npredmax))
  35
  36          do k=1,iv%instid(inst)%nchan          ! loop for channel
  37             npred = iv%instid(inst)%varbc(k)%npred
  38             if (npred <= 0) cycle              ! VarBC channels only
  39
  40            !---------------------------------------------------------------
  41            ! Change of variable (preconditioning)
  42            !---------------------------------------------------------------
  43             varbc_param_tl(:) = 0.0
  44             do i = 1, npred
  45                varbc_param_tl(i) = SUM( cv(iv%instid(inst)%varbc(k)%index(1:npred)) * &
  46                                         iv%instid(inst)%varbc(k)%vtox(i,1:npred) )
  47             end do
  48
  49            !---------------------------------------------------------------
  50            ! TL of bias correction through linear regression
  51            !---------------------------------------------------------------
  52             do n = 1, num_rad                                         ! loop for pixel
  53                if (iv%instid(inst)%tb_qc(k,n) <= qc_varbc_bad) cycle  ! good obs only
  54
  55                 y%instid(inst)%tb(k,n) = y%instid(inst)%tb(k,n) +   &
  56                    SUM( varbc_param_tl(1:npred) *                   &
  57                         iv%instid(inst)%varbc_info%pred(            &
  58                         iv%instid(inst)%varbc(k)%ipred(1:npred),n) )
  59             end do
  60          end do
  61
  62          deallocate(varbc_param_tl)
  63       end do                                   ! end loop for sensor
  64
  65    if (trace_use) call da_trace_exit("da_varbc_tl")
  66
  67  end subroutine da_varbc_tl