Changes between Initial Version and Version 1 of PDAFomi_diag_get_ivar

Timestamp:

Mar 23, 2025, 8:37:08 AM (8 months ago)

Author:

lnerger

Comment:

--

PDAFomi_diag_get_ivar

@@ +1 @@
+= PDAFomi_diag_get_ivar = 
+
+This page documents the routine `PDAFomi_diag_get_ivar` of PDAF, which was introduced with PDAF V3.0. This is part of the PDAF-OMI observation diagnostics module. 
+
+The routine returns a pointer to a vector of the inverse observatino error variances for the specified observation type (`id_obs`).
+
+Usually all PDAFomi_diag routines are called in `prepoststep_pdaf` where the observation information can be retrieved and analyzed.
+
+The interface is the following: 
+{{{
+  SUBROUTINE PDAFomi_diag_get_ivar(id_obs, dim_obs_p_diag, ivar_p_ptr)
+}}}
+with the following arguments:
+{{{
+    INTEGER, INTENT(in) :: id_obs                    !< Index of observation type to return
+    INTEGER, INTENT(out) :: dim_obs_p_diag           !< Observation dimension
+    REAL, POINTER, INTENT(out) :: ivar_p_ptr(:)      !< Pointer to inverse observation error variances
+}}}
+
+**Notes:**
+ * In case of a parallelized model, the vector `ivar_p_prt contains the observed ensemble mean for the process-sub-domain
+ * In Fortran user code the obsevation pointer should be declared in the form[[BR]] `REAL, POINTER :: ivar_p_ptr(:)`[[BR]] It does not need to be allocated. The target vector has the length `dim_obs_p_diag`
+ * If the observation diagnostics have not be activated by using [wiki:PDAFomi_set_obs_diag] the pointer will not be set and `dim_obs_diag=0` will be returned. This value can be checked before assessing the pointer array
+ * If the feature `thisobs%inno_omit` is used (see [wiki:PDAFomi_additional_functionality], the inverse variance of the omitted observations will show the small value set by `inno_omit`. One can use this information to exclude such observations when analyzing differences between observations and observed ensemble.
+
+