System for changing the attitude of linear underwater sensor arrays via neutrally buoyant fluid transfer

Abstract

The attitude of a submerged array of sensing elements can be changed using a fixed quantity of transferable ballast fluid having density different than water. In one embodiment, a non-rigid array of sensor elements is equipped with two expandable reservoirs connected between a flexible conduit which allows the ballast fluid to be transferred back and forth. Pumping fluid between the two reservoirs causes one reservoir to expand while the other contracts. Due to the density difference between the pumped fluid and water, the difference in volume between the two expandable reservoirs causes a shift in the center of buoyancy of the array system. The center of buoyancy in this way becomes offset from the center of gravity of the array system, causing a shift in the attitude of the array. The array can be trimmed, using positively or negatively buoyant static elements, to achieve a specific orientation for given volume ratios between the two expandable reservoirs, and so by controlling the volume ratio, multiple orientations can be selected.