Changes between Version 35 and Version 36 of PDAF_OMI_Overview

Timestamp:

Dec 13, 2021, 2:41:32 PM (2 years ago)

Author:

lnerger

Comment:

--

PDAF_OMI_Overview

@@ -35 +35 @@
 To guarantee that each observation type (like sea surface temperature data from some satellite sensor, or altimetry data) is handled independently from the others one implements with OMI one Fortran module for each observation type.  Thus, different developers can implement observation types without interfering with the implementations by others.
 
-To reduce the coding effort only four routines need to be implemented for an observation type:
+To reduce the coding effort only two routines (in the case of global ensemble filters) or three routines (in the case of localized ensemble filter) need to be implemented for an observation type. Always required are:
  - '''init_dim_obs'''[[br]]
   Reads observations from a file and initialize the information describing the observations
  - '''obs_op'''[[br]]
   Calls an observation operator routine
+For the domain localized filters LETKF/LESTKF/LNETF the following routine is required:
  - '''init_dim_obs_l''' [[br]]
-  Calls a generic routine to initialize local observations (only required for domain-localized filters like LETKF and LESTKF)
+  Calls a generic routine to initialize local observations 
+For the localized EnKF, instead of `init_dim_obs_l` the following routine is used:
  - '''localize_covar'''[[br]] 
-  Calls a generic routine to apply covariance localization (only required for the localized EnKF)
+  Calls a generic routine to apply covariance localization 
+Only in the case of '''3D-Var''', two more routines are required:
+ - '''obs_op_lin'''[[br]]
+  Calls a routine for the linearized observation operator (equal to `obs_op` if this is linear)
+ - '''obs_op_adj'''[[br]]
+  Calls a routine for the adjoint observation operator
 
 The only 'real' coding effort will be in '''init_dim_obs''' because the other routines merely call a routine provided by PDAF-OMI. All functionality needed during the analyis step bases on variables that are initialized by these routines and is provided by PDAF-OMI.