Direction of Arrival Estimation Using Two Hydrophones: Frequency Diversity Technique for Passive Sonar
Peng Li1,2,3, Xinhua Zhang4,5,6, Wenlong Zhang7
1Acoustic Science and Technology Laboratory, Harbin Engineering University, Harbin 150001, China. arthuralecto@hrbeu.edu.cn.
Sensors (Basel, Switzerland)
|May 1, 2019
Summary
This study introduces a new frequency diversity algorithm for passive azimuth estimation using two hydrophones. It achieves clear target trajectories at lower signal-to-noise ratios (SNRs) than traditional methods.
Area of Science:
- Acoustics
- Signal Processing
- Oceanography
Background:
- Traditional passive azimuth estimation requires high signal-to-noise ratios (SNRs) for accurate target trajectory estimation.
- Existing methods like cross-correlation and cross-spectral phase estimation are limited by noise sensitivity.
Purpose of the Study:
- To propose a novel passive azimuth estimation algorithm utilizing frequency diversity.
- To enhance target trajectory clarity and robustness at lower SNRs.
Main Methods:
- Developed a two-hydrophone algorithm applying frequency diversity techniques.
- Calculated the cross-spectral density matrix to remove initial phase differences across frequencies.
- Utilized inter-frequency phase information for beamforming to improve signal processing gain.
Main Results:
- The proposed algorithm successfully estimated target azimuth at SNRs of -16 dB (single target) and -10 dB (multiple targets).
- Demonstrated robustness in low SNR conditions where cross-correlation methods failed.
- Outperformed conventional broadband beamforming with a 64-element array on rich frequency data.
Conclusions:
- Frequency diversity significantly improves passive azimuth estimation performance in low SNR environments.
- The novel algorithm offers a more robust and effective solution for underwater target tracking.
- Validated through simulations and real-world datasets (swell96 and South Sea).
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