Range-dependent geoacoustic inversion of vertical line array data using matched beam processing.

Area of Science:

• Oceanography
• Geophysics
• Acoustics

Background:

• Accurate geoacoustic property estimation is vital for underwater acoustic propagation modeling.
• Previous methods often struggle with range-dependent environments and low-angle arrivals.
• The East Sea presents complex geoacoustic conditions requiring advanced inversion techniques.

Purpose of the Study:

• To develop and validate a range-dependent geoacoustic inversion scheme using vertical line array data.
• To estimate geoacoustic properties along a radial track in the East Sea.
• To improve the accuracy of geoacoustic inversion by addressing challenges like low-angle arrivals.

Main Methods:

• Utilized vertical line array data from the 4th Matched Acoustic Properties and Localization Experiment.
• Employed a sectorwise inversion scheme, dividing the acoustic path into segments for sequential analysis.
• Implemented matched beam processing with beam filtering to mitigate the influence of low-angle arrivals on the cost function.

Main Results:

• Successfully estimated range-dependent geoacoustic properties up to 7.5 km from the vertical line array.
• Inversion results demonstrated consistency with existing geophysical databases.
• Validated the geoacoustic model through matched-field source localization using independent frequency data.

Conclusions:

• The proposed sectorwise inversion algorithm effectively estimates range-dependent geoacoustic properties.
• Matched beam processing enhances the reliability of inversion by reducing low-angle arrival interference.
• The validated geoacoustic model provides a reliable representation of the East Sea seabed for acoustic propagation studies.