Changes between Version 18 and Version 19 of InsertAnalysisStep

Timestamp:

Oct 3, 2026, 10:05:37 AM (15 hours ago)

Author:

lnerger

Comment:

--

InsertAnalysisStep

@@ -179 +179 @@
 == Compilation and testing ==
 
-To compile the extended model code with PDAF, one has to extend the Makefile for the model by adding the additional user-supplied routines. While all of the user-supplied routines need to exist not all of them need to be fully implemented at this time if the following procedure is used. The routines that will not be called are `U_init_dim_obs`, `U_obs_op`, `U_init_obs`, `U_prodRinvA`, `U_init_obsvar`. A simple way to provide them for the compilation could be to copy the corresponding files (i.e. named without `U_`) from the template directory `templates/` and to include these files in the compilation and linking. These templates are simple stubs without any functionality.
+To compile the extended model code with PDAF, one has to adapt the Makefile for the model by adding the additional user-supplied routines. While all of the user-supplied routines need to exist not all of them need to be fully implemented at this time if the following procedure is used. The routines that will not be called are `U_init_dim_obs`, `U_obs_op`, `U_init_obs`, `U_prodRinvA`, `U_init_obsvar`. We recommend to base on the template code from `templates/` which provide the routines without functionality. Thus one can copy all files from the template directory `templates/` and to include these files in the compilation and linking. 
 
 At this implementation stage one can use the preprocessor definition `PDAF_NO_UPDATE` (available from Version 1.6.1). With this, the actual analysis step of the chosen filter algorithm is not executed. Accordingly, only the user-supplied routines used in `PDAF_get_state` as well as the routine `U_collect_state` need to be implemented with functionality. The other routines will not be executed, because they are only called during the analysis step. Generally with `PDAF_NO_UPDATE` the program performs just an ensemble integration. That is, PDAF is initialized by `PDAF_init`. Then a forecast is computed by using `PDAF_get_state` and the chosen `PDAF_assimilate_X` routine. At the initial time `U_prepoststep` is executed by `PDAF_get_state`. `U_next_obs` will provide the number of time steps to be computed by the model and `U_distributed_state` will initialize the model fields. Subsequently the ensemble integration is performed and the forecast fields are written back to the ensemble array by `U_collect_state`. Upon completion of the forecast phase, the routine `U_prepoststep` is executed twice. The first time is the regular call before the analysis is executed. Thus, it allows to access the forecast ensemble. If the analysis would not be deactivated, the second call to `U_prepoststep` would be after the analysis allowing access to the ensemble directly after the analysis. As the analysis is deactivated here, the ensemble will be the same as in the first call.