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Periodic extension phase unwrapping for direction-of-arrival estimation using sparse undersampled arrays: Method and
Wei Ma1, Chuan Tian2, Chengcai Lyu2
1College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310027, China.
The Journal of the Acoustical Society of America
|May 28, 2026
Summary
This study introduces Periodic Extension Phase Unwrapping (PEPU) to solve spatial aliasing and phase ambiguity in underwater acoustic arrays. PEPU enhances direction-of-arrival estimation accuracy for sparse arrays in challenging marine environments.
Area of Science:
- Acoustics
- Signal Processing
- Array Signal Processing
Background:
- Underwater acoustic arrays face challenges with spatial aliasing and phase ambiguity.
- Sparse and undersampled arrays exacerbate these issues in direction-of-arrival (DOA) estimation.
- Existing methods struggle with broadband signals and complex acoustic environments.
Purpose of the Study:
- To develop a robust phase unwrapping method for broadband DOA estimation.
- To address spatial aliasing and phase ambiguity in sparse underwater acoustic arrays.
- To improve the stability and accuracy of DOA estimation in challenging conditions.
Main Methods:
- Periodic Extension Phase Unwrapping (PEPU) is proposed.
- Extends wrapped cross-spectral phase to create a candidate phase space.
- Utilizes local phase smoothness and cross-frequency continuity for dominant trajectory extraction.
- Employs global trajectory screening to suppress anomalies.
Main Results:
- PEPU effectively suppresses anomalies from multipath propagation and interference.
- Demonstrates improved stability in broadband phase unwrapping for large-spacing arrays.
- Provides reliable phase input for ambiguity-free DOA estimation.
- Validated through sea trials in the South China Sea.
Conclusions:
- PEPU offers a stable and reliable solution for phase unwrapping in sparse underwater acoustic arrays.
- Enhances the accuracy of broadband DOA estimation in complex acoustic environments.
- Reduces the impact of anomalous frequency bins and nonstationary disturbances.
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