Detection Rate Improvements Through Understanding and Modeling Ocean Variability

The littoral environment is especially demanding on tactical sonar systems, in large part because the spatial and temporal variability imposes sonar system operating conditions of a nature and with a scale heretofore not encountered in the open oceans. Recent Office of Naval Research (ONR) sponsored basic research as well as fleet exercises have shown that littoral environments tactically important to the US Navy have rapidly varying sound speed profiles (direction and time dependent) along with directional wind-wave conditions and horizontally anisotropic bottom properties that result in spatial and temporal anisotropies in transmission loss. Most existing TL models within fleet Tactical Development Aids (TDAs) and System Performance Prediction (SPP) capabilities are accurate when the inputs are appropriately modeled and accounted for. But often there are not enough sensors in the water to sample the temporal and spatial variability sufficiently and the model outputs are inaccurate. This proposal addresses these deficiencies in acoustic models by leveraging highly-sampled GFI measurements of oceanographic variability to inform sonar detection uncertainty estimates and predictions of sensor-level output, to aid asset placement, enhance test planning, and improve accuracy of post-test reconstruction.