pyPDAF.PDAFomi.init_dim_obs_l_iso

pyPDAF.PDAFomi.init_dim_obs_l_iso()

Initialize the observation information corresponding to an isotropic local analysis domain.

One can set localization parameters, like the localization radius, for each observation type.

The function has to be called in user-supplied function of init_dim_obs_l_OBTYPE in each observation module if a domain-localized filter (LESTKF/LETKF/LNETF/LSEIK)is used.

It initialises the local observation information for PDAF-OMI for a single local analysis domain. This is used for isotropic localisation where the localisation radius is the same in all directions.

See also relevant PDAF wiki page

Parameters:

  • i_obs (int) – index of observation type

  • coords_l (ndarray[tuple[ncoord, ...], np.float64]) – Coordinates of current analysis domain The array dimension ncoord is number of coordinate dimension

  • locweight (int) – Types of localization function 0) unit weight; 1) exponential; 2) 5-th order polynomial; 3) 5-th order polynomial with regulatioin using mean variance; 4) 5-th order polynomial with regulatioin using variance of single observation point;

  • cradius (float) – Vector of localization cut-off radii; observation weight=0 if distance > cradius

  • sradius (float) – Vector of support radii of localization function. It has no impact if locweight=0; weight = exp(-d / sradius) if locweight=1; weight = 0 if d >= sradius else f(sradius, distance) if locweight in [2,3,4].

  • cnt_obs_l_all (int) – Local dimension of current observation vector

Returns:

cnt_obs_l_all – Local dimension of current observation vector

Return type:

int