28 | | Compared to the classical variant to implement observations with PDAF, OMI is designed to reduce the coding effort for implementing the support for an observation type, its corresponding observation operator, and localization. In particular, only four routines need to be implemented for an observation type: |

| 28 | Compared to the classical variant to implement observations with PDAF, OMI is designed with two main aims |

| 29 | 1. reduce the coding effort for implementing the support for an observation type, its corresponding observation operator, and localization. |

| 30 | 2. simplify the implementation of complex cases in which several different observation types are assimilated by clearly separating each observation type |

| 31 | |

| 32 | With OMI one implements one Fortran module for each observation type (like sea surface temperature data from some satellite sensor, or altimetry data). This guarantees that each observation type is handled indenpendently from the others. Thus, different developers can implement observation types without interfering with the implementations by others. |

| 33 | |

| 34 | To reduce the coding effort only four routines need to be implemented for an observation type: |