Changes between Initial Version and Version 1 of U_g2l_obs

Timestamp:

Jan 21, 2016, 5:01:08 PM (9 years ago)

Author:

lnerger

Comment:

--

U_g2l_obs

@@ +1 @@
+= U_g2l_obs =
+
+The page document the user-supplied call-back routine `U_g2l_obs`.
+
+The routine `U_g2l_obs` is a call-back routine that has to be provided by the user. In the simplified interface the predefined name of the routine is `g2l_obs_pdaf`, but in the full interface, the user can choose the name of the routine.
+The routine is used with all filter algorithms using domain-localization (LSEIK, LETKF, LESTKF) and is independent of the particular algorithm.
+The routine is called during the loop over the local analysis domains in the analysis step. It has to provide a local observation vector `mstate_l` for the observation domain that corresponds to the local analysis domain with index `domain_p`. Provided to the routine is the full observation vector `mstate_f` from which the local part has to be extracted.
+
+The interface is the following:
+{{{
+SUBROUTINE g2l_obs(domain_p, step, dim_obs_f, dim_obs_l, mstate_f, mstate_l)
+}}}
+with
+ * `domain_p` : `integer, intent(in)`[[BR]] Index of current local analysis domain
+ * `step` : `integer, intent(in)`[[BR]] Current time step
+ * `dim_obs_f` : `integer, intent(in)`[[BR]] Size of full observation vector for model sub-domain
+ * `dim_obs_l` : `integer, intent(in)`[[BR]] Size of observation vector for local analysis domain
+ * `mstate_f` : `integer, intent(in), dimension(dim_p)`[[BR]] Full observation vector for model sub-domain
+ * `mstate_l` : `integer, intent(out), dimension(dim_l)`[[BR]] Observation vector for local analysis domain
+
+Hints:
+ * The  vector `mstate_f` that is provided to the routine is one of the observed state vectors that are produced by `U_obs_op_f`.
+ * Some operations performed here are analogous to those required to initialize a local vector of observations in `U_init_obs_l`. If that routine reads first a full vector of observations (e.g. in `U_init_dim_obs_f`), this vector has to be restricted to the relevant observations for the current local analysis domain. For this operation, one can for example initialize an index array when `U_init_dim_obs_l` is executed. (Which happens before `U_g2l_obs`)