Development, Implementation, and Testing of a Comprehensive Method for Integrating Acoustic Observations into Dynamic Ocean Models to Provide Enhanced

The Phase II component of this SBIR will deal with work to a) research, implement, test, and refine technology related to the assimilation of ocean acoustic data into an ocean circulation model and b) develop the specific software/hardware framework for a covert, forward-deployable Coupled Oceanographic/Tomographic Analysis and Prediction System (COTAPS) for undersea warfare. The Phase II objectives would build on our previous work in assimilating acoustic travel time information into an ocean circulation model. SSI has developed a preliminary method for transforming acoustic travel time information into corresponding ocean model variables. This method has been implemented into the data assimilation scheme of the Physical-space Statistical Analysis System (PSAS). Initial testing of this model-oriented acoustic assimilation technique at the Pacific Missile Range Facility (PMRF), revealed that it significantly reduced the scatter of the model-predicted temperatures relative to observed temperatures. The Phase II work will include the full implementation and testing of the COTAPS technology at PMRF. We will develop and implement the full set of expressions for estimating and assimilating water column temperatures (T), salinities (S), and currents (U) based on acoustic arrival time information. The work will also include establishing as part of the national ocean laboratory at PMRF an automated oceanographic/tomographic analysis and prediction system that will produce products on a daily basis. A demonstration of the PMRF COTAPS will be conducted in which SSI will perform a comparison of model and observed T, S, and U with and without tomographic data assimilation. We will quantify the model errors to ascertain the degree (positive and negative) to which tomographic assimilation impacts the model solutions. This will provide the basis from which SSI will develop the specific software-hardware framework of a forward-deployable COTAPS for undersea warfare.