Passive acoustic identification tags for marking underwater docking stations

Navigation of autonomous underwater vehicles requires accurate positioning information, notably during docking and homing operations. This letter demonstrates the feasibility of using a constellation of passive Acoustic Identification (AID) to enable accurate localization of a docking station by an of autonomous underwater vehicle. Scaled experiments are conducted using a pair of AID tags composed of multiple concentric hemispherical acrylic layers, each of which generates a unique backscattered acoustic signature when ensonified by a broadband ultrasonic transducer. A parameterized signal processing detection methodology is implemented to improve the detectability of AID tags in the presence of clutter.