A method for target detection in complex acoustic environments using unmanned underwater vehicle motion

Area of Science:

• Underwater acoustics
• Signal processing
• Robotics

Background:

• Platform self-noise and ambient noise significantly limit acoustic target detection performance in unmanned underwater vehicles (UUVs).
• Complex acoustic environments feature overlapping spectral and spatial characteristics of flow noise, propeller noise, and ambient noise with target signals, degrading noise suppression.
• Existing methods struggle with effective noise suppression without prior information or compromising target signal integrity.

Purpose of the Study:

• To investigate the signal and noise characteristics during UUV motion for improved acoustic target detection.
• To develop a novel method for complex noise suppression by exploiting variations in signal incidence angle relative to the UUV's heading angle.
• To enhance the detection performance of weak acoustic targets in challenging underwater conditions.

Main Methods:

• Analysis of signal and noise characteristics, including platform self-noise, ambient noise, and their spectral/spatial properties during UUV operation.
• Exploitation of the varying signal incidence angle with the UUV's heading angle for signal-noise separation.
• Development of a noise suppression technique leveraging signal-noise separation with minimal prior information.

Main Results:

• The proposed method effectively suppresses complex noise, including flow, propeller, and ambient noise.
• The technique demonstrates robustness, requiring little prior information for operation.
• Experimental results confirm that the target signal's integrity is preserved during noise suppression.

Conclusions:

• The developed method offers a significant advancement in acoustic target detection for UUVs operating in complex noise environments.
• Exploiting the dynamic relationship between signal incidence angle and UUV heading provides an effective strategy for signal-noise separation.
• The approach enhances the capability to detect weak targets, improving UUV's overall acoustic sensing performance.