= PDAFomi_obs_op_adj_interp_lin = This page documents the routine `PDAFomi_obs_op_adj_interp_lin` of PDAF-OMI. The routine provides an adjoint observation operator for observations that are computed as the linear interpolation between some grid point values in the state vector. It is usually called in `obs_op_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_interp_lin(thisobs, nrows, obs_f_all, state_p) TYPE(obs_f), INTENT(inout) :: thisobs ! Data type with full observation INTEGER, INTENT(in) :: nrows ! Number of values to be averaged 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. * The interpolation coefficients have to be initialized in `init_obs_OBSTYPE` of the observation module.