Acoustic navigation of a large-aperture array

The acoustic navigation system for a large aperture (900 m) vertical array and the resulting data, describing the motion of the array and research platform FLIP during a 20‐day deployment in the NE Pacific, are presented. Acoustic navigation data are acquired by detecting the high‐frequency signals emitted by near bottom transponders. Recorded travel times are converted to xyz positions by a nonlinear least‐squares approach that adjusts the transponder, FLIP, and the array positions, minimizing the rms error. Simulation results highlight error sensitivities. The movement of FLIP, although constrained by a three‐point moor, exhibits a wind‐driven component and a clockwise semidiurnal tidal component with horizontal displacements in excess of 300 m. Suspended vertically from FLIP under tension, the array has a damped response to tidal and internal wave forces. [Work supported by ONT.]