= PDAFomi_obs_op_adj_gridpoint =

This page documents the routine `PDAFomi_obs_op_adj_gridpoint` of PDAF-OMI.

The routine provides an adjoint observation operator for observations that are grid point values in the state vector. It is usually called in `obs_op_adj_OBSTYPE` in an [wiki:OMI_observation_modules OMI observation module] if a 3D-Var method is used.

|| See the [wiki:OMI_observation_operators page describing PDAF-OMI observation operators] for a general overview.||

The interface is:
{{{
  SUBROUTINE PDAFomi_obs_op_adj_gridpoint(thisobs, obs_f_all, state_p)

    TYPE(obs_f), INTENT(inout) :: thisobs      ! Data type with full observation
    REAL, INTENT(in)           :: obs_f_all(:) ! Full observed state for all observation types (array provided by PDAF)
    REAL, INTENT(inout)        :: state_p(:)   ! Process-local model state provided by PDAF
}}}

'''Note:'''
 * The necessary index information for the observation operator was initialized in `init_obs_OBSTYPE` of the observation module.