(omi:tsmp-pdaf-with-pdaf-omi)=
# TSMP-PDAF with PDAF-OMI

PDAF-OMI for multivariate data assimiliaton.
It is design to handle different observation types (currently soil moisture and TWS) automatically.
Additional to current observation files, the observation type has to be included (SM, GRACE).

See also create observation script for details: https://icg4geo.icg.kfa-juelich.de/ExternalRepos/tsmp-pdaf/tsmp-pdaf-observation-scripts/-/tree/main/omi_obs_data?ref_type=heads

PDAF-OMI can be switched on by the command line option
[use_omi](cmd:use_omi).

Both global and local filters can be used. To enable multi-scale data assimilation, different localization radii for different observation types can be passed. Note that the localization radius for SM is currently in km and for GRACE in #gridcells.

If questions arise contact ewerdwalbesloh@geod.uni-bonn.de

## Observation File Format

The reader `read_obs_nc_type` expects the following variables in each
observation file:

| NetCDF name  | Type                     | Required?       |
|--------------|--------------------------|-----------------|
| `dim_obs`    | dimension                | yes             |
| `obs_clm`    | `REAL(dim_obs)`          | yes             |
| `type_clm`   | `CHARACTER(20)(dim_obs)` | yes             |
| `lon`        | `REAL(dim_obs)`          | yes             |
| `lat`        | `REAL(dim_obs)`          | yes             |
| `layer`      | `INTEGER(dim_obs)`       | yes             |
| `dr`         | `REAL(2)`                | yes             |
| `obserr_clm` | `REAL(dim_obs)`          | if `multierr=1` |
| `obscov_clm` | `REAL(dim_obs,dim_obs)`  | if `multierr=2` |

Files follow the naming convention `<obs_filename>.<NNNNN>`
(five-digit zero-padded PDAF step).

The [`type_clm`](obs:files:clm:typeclm) field must be homogeneous
within a file - a file containing GRACE observations cannot
simultaneously contain SM or C observations.