Accelerated Deconvolved Imaging Algorithm for 2D Multibeam Synthetic Aperture Sonar.

Area of Science:

• Ocean Engineering
• Acoustical Imaging
• Remote Sensing

Background:

• Underwater acoustical surveying is crucial for ocean engineering but faces limitations in accuracy and resolution.
• Traditional methods like Multibeam Echo Sounder (MBES) and Synthetic Aperture Sonar (SAS) suffer from decreased resolution with range and sidelobe interference.
• These issues reduce the accuracy of underwater images and hinder applications like subaqueous tunnel construction and resource prospecting.

Purpose of the Study:

• To develop a novel imaging method that overcomes existing theoretical limitations for higher accuracy underwater acoustical surveying.
• To propose an accelerated deconvolved Multibeam Synthetic Aperture Sonar (MBSAS) beamforming method.
• To improve the convergence velocity and imaging performance compared to classical methods.

Main Methods:

• Introduced exponential acceleration and vector extrapolation to the Richardson-Lucy (R-L) iteration for deconvolution.
• Developed an accelerated deconvolved MBSAS beamforming method.
• Validated the method through simulations, tank tests, and field experiments.

Main Results:

• The proposed method achieves a narrow beamwidth and a high sidelobe ratio in few iterations.
• Demonstrated improved convergence velocity compared to the classical R-L iteration.
• Successfully applied to actual engineering scenarios, overcoming transducer array scale limitations.

Conclusions:

• The accelerated deconvolved MBSAS beamforming method significantly enhances underwater acoustical surveying accuracy.
• This technique enables 3D high-accuracy surveying using a 2D MBES transducer array system.
• The method shows wide applicability in underwater acoustical remote sensing and ocean engineering.