Methods for Measuring an Acoustic Array’s Straightness and for Autonomous Mechanical Straightening to Avoid Contact with Sea Bottom Under All Operatio

The Navy uses towed arrays in the long-range tracking of submarine contacts. The acoustic performance of the array is dependent on the straightness of the array which is subject to “drooping” as ship velocities decrease and to bending and turning due to currents. The Navy is seeking innovation to autonomously straighten the array and protect the array from damage due to seafloor dragging. Makai developed a proof-of-concept design in the Phase I award which consisted of a towed body which clamps to the aft ends of the port and starboard arrays providing uniform drag resistance. This passively controlled towed body has been demonstrated, through numerical modeling and at-sea results testing, to provide at least 20% and up to 50% in the array depth control, and an array straightness of less than +/-2 ft, reducing array droop and damage from the sea floor.For Phase II, Makai proposes to complete the design of a full-scale 2.2m and 4.4m SURTASS Array Straightening System (SASS), build and construct a first-gen and second-gen prototype, and perform a series of at-sea tests in order to evaluate and demonstrate the SASS performance. This work will result in developing the SASS to Technology Readiness Level (TRL) 6/7.