A deep-water ray-based blind deconvolution for a near-surface source with a bottom-moored short-aperture vertical array.

Zhezhen Xu,Kunde Yang,Peilin Li,Hui Li

doi:10.1121/10.0009380

Abstract

A deep-water ray-based blind deconvolution (DW-RBD) method for estimating the channel impulse response of a near-surface source with a bottom-moored vertical array is developed. The proposed DW-RBD is an alternative when the original RBD suffers from performance degradation due to the insufficient beam resolution. The signal-processing scheme coherently utilizes the information of multipath time-delay implied in the conventional wideband beamforming output. A time-delay-related compensation term is then derived based on image theory and introduced into the original RBD to enhance multipath separation. Both simulation and experimental results demonstrate the effectiveness of the proposed method.

Highlights

In deep water, a well-known acoustic propagation waveguide is the so-called reliable acoustic path (RAP),1 which refers to the direct (D) and possibly the surface-reflected (SR) paths between a shallow source and a deep receiver
We find that the original ray-based blind deconvolution (RBD) suffers from performance degradation for a near-surface source when processing the experimental data collected under the RAP environment
This Letter describes how the RBD technique can be applied for the channel impulse response (CIR) estimation of a near-surface source with a short-aperture VLA under a RAP environment

Summary

Introduction

A well-known acoustic propagation waveguide is the so-called reliable acoustic path (RAP), which refers to the direct (D) and possibly the surface-reflected (SR) paths between a shallow source and a deep receiver. It is meaningful to estimate the time delays between these four arrival paths for further applications such as ray separation, source waveform reconstruction, and channel equalization. The original RBD acquires the source phase using conventional wideband beamforming (CWBF) along a well-resolved ray path, and estimates the CIR with this phase information. In this Letter, a deep-water ray-based blind deconvolution (DW-RBD) method is proposed to address the problem of insufficient beam resolution. In this case, the output beam of CWBF steered towards the angle with maximum beam power contains both the D and SR paths. The beam output is reconstructed and its phase is used to phase-rotate the received signals for CIR estimation. The proposed method is demonstrated by using experimental recordings from a ship of opportunity

Theory

Simulation demonstration

Experiment

Conclusions