Changes between Initial Version and Version 1 of U_init_dim_obs_f

Jan 21, 2016, 1:53:22 PM (5 years ago)



  • U_init_dim_obs_f

    v1 v1  
     1= U_init_dim_obs_f =
     3The page document the user-supplied call-back routine `U_init_dim_obs_f`.
     5The routine `U_init_dim_obs_f` is a call-back routine that has to be provided by the user. In the simplified interface the predefined name of the routine is `init_dim_obs_f_pdaf`, but in the full interface, the user can choose the name of the routine.
     6The routine is used with all filter algorithms suing domain-localization (LSEIK, LETKF, LESTKF) and is independent of the particular algorithm.
     7The routine is called at the beginning of each analysis step, before the loop over all local analysis domains is entered. It has to initialize the size of the full observation vector according to the current time step. For simplicity, this size can be the number of observations for the global model domain.
     9The interface is the following:
     11SUBROUTINE U_init_dim_obs_f(step, dim_obs_f)
     14 * `step` : `integer, intent(in)`[[BR]] Current time step
     15 * `dim_obs_f` : `integer, intent(out)`[[BR]] Size of the full observation vector
     17Some hints:
     18 * It can be useful to not only determine the size of the observation vector at this point. One can also already gather information about the location of the observations, which can be used later, e.g. to implement the observation operator. In addition, one can already prepare an array that holds the full observation vector. This can be used later by `U_init_obs_l` to initialize a local vector of observations by selecting the relevant parts of the full observation vector. The required arrays can be defined in a module like `mod_assimilation`.
     19 * The routine is similar to `U_init_dim_obs` used in the global filters. However, if the global filter is used with a domain-decomposed model, it only initializes the size of the observation vector for the local model sub-domain. This is different for the local filters, as the local analysis also requires observational data from neighboring model sub-domains. Nonetheless, one can base on an implemented routine `U_init_dim_obs` to implement `U_init_dim_obs_f`.