Technology for Shipbuilding Affordability

This SBIR proposes the design of an expendable sensor system for in-situ measurement of bottom characteristics such as bottom loss and bottom back-scatter. The data would be inputs to acoustic performance models such as Tactical Decision Aids (TDAs). Thissensor system will obtain real time environmental data in shallow water to optimize the deployment and performance of acoustic sensors such as Air Deployable Active Receiver (ADAR), Advanced Low Frequency Sonar (ALFS), and Directional Command ActiveSonobuoy System (DICASS). The unique features of this proposal concept are near bottom sensor strings combined with near bottom small sources to obtain bottom characteristics at low grazing angles without the need for large high power sources. The sourcesproposed here are only 170 (dB//uPA2 in a one-octave band) compared to the 200 to 215 (dB//uPA2 in a one-octave band) source level required by near surface measurement systems. The proposed system also utilizes an in-buoy processing system to computebottom loss and bottom back-scatter from measurements of signal level and arrival times. Only results that can be directly input to TDA will be transmitted to tactical aircraft adding no additional processing burden on the tactical aircraft system.Thisproposed device will satisfy a critical need for a rapid response environmental measurement system to acquire data and in-situ measurements for accurate on site tactical decision aids, nowcast active sonar predictions and buoy deployment geometryoptimization, and perform this task in a more environmentally friendly manner with smaller sources. This development will allow the measurement of ocean bottom parameters safely at sites close to shore and at sites which are off-limits to the currentlarge source level system. Commercial markets include offshore environmental bottom sediment data collection, coastal environmental studies and potentially off shore oil exploration.