Omnidirectional passive acoustic identification tags for underwater navigation

Area of Science:

• Acoustics
• Materials Science
• Robotics & Control

Background:

• Passive acoustic identification (AID) tags are crucial for underwater navigation and object recognition.
• Existing methods may face limitations in orientation-independent identification.
• The need for robust, passive systems for underwater acoustic tagging is growing.

Purpose of the Study:

• To introduce a novel class of passive acoustic identification (AID) tags with curved symmetry.
• To demonstrate their capability for orientation-independent underwater navigation.
• To establish a method for engineering unique acoustic responses for identification.

Main Methods:

• Design of AID tags using radially stratified shells with curved symmetry.
• Utilizing monostatic configuration for backscattering unique specular reflection patterns.
• Numerical prediction of acoustic response in the high-frequency regime assuming horizontally stratified layers.
• Experimental validation using scaled 3D printed hemispherical shells.

Main Results:

• AID tags generate unique specular reflection patterns, functioning as acoustic bar-codes.
• The acoustic response is independent of incidence orientation in a monostatic setup.
• The specular component of the AID tag's response can be accurately predicted numerically.
• Scaled experiments successfully demonstrated the principles with 3D printed shells.

Conclusions:

• The presented AID tags offer a robust solution for orientation-independent underwater acoustic identification.
• The design allows for unique signature engineering through material properties and shell thicknesses.
• Numerical prediction provides a reliable tool for designing and understanding AID tag performance.
• This technology holds promise for advancing underwater navigation and tracking systems.