Observational feedback data encoded at ECMWF and member states and collaborators like Met Office are encoded according to codes documented in ODB Governance database.

The ODB governance process was started as part of preparations to archive operational observational feedback data in MARS. Its goal was to ensure consistency of metadata (structure) and codes of observational feedback data produced by ECMWF operational suite and experiments, as well as facilitate future exchange of observational data between meteorological centres.

Another goal of ODB Governance database is to provide a central place to document ODB column names, their content and units.

Report type and observational groups

During the ODB archival project a new classification was devised, called Report Type. It is a single classification used to index any observational data in ECMWF MARS archive. Both MARS language keyword and ODB column corresponding to Report Type classification are called reportype. The column contains numeric codes.

Additionally, Observation Group groups similar report types that share common structure (meta data). MARS client can conveniently expand given observation group provided with keyword OBSGROUP to a list of report types. ODB column corresponding to Observation Group is called groupid and contains numeric codes.