OWAQ supports observation systems through the Observing System Simulation Experiments (OSSE) Test bed. The OSSE is used to determine the potential impact of proposed space-based, sub-orbital, and in-situ observing systems on analyses and forecasts. It is also being used to evaluate trade-offs in observing system design and assess proposed methodology for assimilating new observations in coordination with the Joint Center for Satellite Data Assimilation (JCSDA). Finally, the OSSE is being used to provide guidance for operational observation deployment and construction of national observation networks meeting weather, ocean and climate needs. Sub-objectives are to define both the advantages and limitations of a hierarchy of OSSE's that include rapid prototyping of instrument or data assimilation concepts, as well as the more rigorous "full" OSSE's, and to generate an OSSE/OSE process that invites participation by the broad community of agency planners, research scientists and operational centers.