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subroutine da_varbc_direct (iv) 1,2
!---------------------------------------------------------------------------
! PURPOSE: Apply bias correction to radiance innovations.
!
! METHOD: d = y - H(x) - bc
! bc = SUM( beta_i Pred_i )
! i
! beta = VarBC parameters
! Pred = Bias predictors
!
! Called from da_get_innov_vector_radiance
!
! HISTORY: 10/26/2007 - Creation Tom Auligne
!---------------------------------------------------------------------------
implicit none
type (iv_type), intent(inout) :: iv ! O-B structure.
integer :: inst, k, n, npred, npredmax
if (trace_use) call da_trace_entry
("da_varbc_direct")
do inst = 1, iv%num_inst ! loop for sensor
npredmax = iv%instid(inst)%varbc_info%npredmax
write(unit=stdout,fmt='(A,A)') 'VARBC: Applying bias correction for ', &
trim(iv%instid(inst)%rttovid_string)
do k=1,iv%instid(inst)%nchan ! loop for channel
npred = iv%instid(inst)%varbc(k)%npred
if (npred <= 0) cycle ! VarBC channel only
do n= iv%instid(inst)%info%n1,iv%instid(inst)%info%n2 ! loop for pixel
! apply bias correction through linear regression
!-------------------------------------------------
if ( iv%instid(inst)%tb_inv(k,n) > missing_r ) then
iv%instid(inst)%tb_inv(k,n) = iv%instid(inst)%tb_inv(k,n) - &
SUM( iv%instid(inst)%varbc(k)%param(1:npred) * &
iv%instid(inst)%varbc_info%pred( &
iv%instid(inst)%varbc(k)%ipred(1:npred),n) )
end if
end do
end do
end do ! end loop for sensor
if (trace_use) call da_trace_exit("da_varbc_direct")
end subroutine da_varbc_direct