U_init_obsvars

The page documents the user-supplied call-back routine U_init_obsvars, which was introduced with PDAF V3.0.

The routine U_init_obsvars is a call-back routine that has to be provided by the user. The typical name in user code is init_obsvars_pdaf, but the user can choose the name. The routine is used only with the ENSRF/EAKF.

The routine is called by PDAF during the analysis step and has to provide the filter with a vector of observation error variances.

The interface is:

SUBROUTINE U_init_obsvars(step, dim_obs_f, var_f)

  INTEGER, INTENT(in) :: step           ! Current time step
  INTEGER, INTENT(in) :: dim_obs_f      ! Dimension of full observation vector
  REAL, INTENT(out) :: var_f(dim_obs_f) ! vector of observation error variances

The variance vector var_f is for the full observation vector.