Version 5 (modified by 8 months ago) (diff) | ,
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PDAFomi_init_dim_obs_l
This page documents the routine PDAFomi_init_dim_obs_l
` of PDAF-OMI.
The routine has to be called in init_dim_obs_l_OBTYPE
in each observation module if a domain-localized filter (LESTKF/LETKF/LNETF/LSEIK)is used. It initializes the local observation information for PDAF-OMI for a single local analysis domain
See the page describing PDAF-OMI observation modules for the full documentation of OMI observation modules. |
The interface is:
SUBROUTINE PDAFomi_init_dim_obs_l(thisobs_l, thisobs, coords_l, locweight, lradius, & sradius, dim_obs_l) TYPE(obs_f), INTENT(inout) :: thisobs ! Data type with full observation TYPE(obs_l), INTENT(inout) :: thisobs_l ! Data type with local observation REAL, INTENT(in) :: coords_l(:) ! Coordinates of current local analysis domain INTEGER, INTENT(in) :: locweight ! Type of localization function [scalar or vector, see below] REAL, INTENT(in) :: cradius ! Localization cut-off radius [scalar or vector, see below] REAL, INTENT(in) :: sradius ! Support radius of localization function [scalar or vector, see below] INTEGER, INTENT(inout) :: dim_obs_l ! Local dimension of current observation vector
Notes:
- The output value
dim_obs_l
of the routine is the number of local observations for the local analysis domain for which the routine is called. - The coordinate vector
coords_l
has be set consistently with the observation coordinates specified ininit_dim_obs_OBSTYPE
. - a convenient place to initialize
coords_l
is ininit_dim_l
. The templates and tutorial codes show this approach. (see the page on implementing the local analysis step) locweight
,cradius
andsradius
can be set to the same values for all local analysis domains. However, the interface allows the user to specify different localization radii and weight functions for each single local analysis domain depending on the indexdomain_p
or the coordinatescoords_l
.
Settings for non-isotropic localization
Introduced with PDAF V2.2 a non-isotropic localization is possible for this use vectors for cradius
and lradius
. This in the interface of PDAFomi_init_dim_obs_l
one can use
REAL, INTENT(in) :: cradius(:) ! Localization radius REAL, INTENT(in) :: sradius(:) ! Support radius of localization function
Here, the size cradius
and sradius
has to be equal to thisobs%ncoords
.
Setting different weight functs for horizontal and vertical directions
In case of the non-isotropic localization is used with 2D+1D factorized distances one can specify different weight functions for the vertical and horizontal directions. This should be particularly useful when using the 2D+1D factorized localization (see exaplanation of possible choices of thisobs%disttype >). The interface accepting separate weight functions is
INTEGER, INTENT(in) :: locweight(2) ! Type of localization function [scalar or vector, see below] REAL, INTENT(in) :: cradius(:) ! Localization radius REAL, INTENT(in) :: sradius(:) ! Support radius of localization function
Now, locweight(1)
specifies the localization function in the horizontal direction, while locweight(2)
specifies the localization function in the vertical direction (see the the table of choices of localization functions).