Quaternion-Based Two-Dimensional DOA Estimation for Coherent Underwater Sources Without Eigendecomposition

For scenarios of coherent underwater sources at low signal-to-noise ratio (SNR), a novel quaternion-based DOA algorithm without eigendecomposition is proposed using linear vector-hydrophone array. We construct four quaternion models by judiciously arranging the received data to fully utilize statistical information incident signals. To avoid high computational complexity caused eigenvalue decomposition (EVD), we introduce computationally efficient propagator method (PM) estimate elevation angles observed In algebra framework, statistically eliminate additive noise, which makes PM exhibit robust performance in SNR. By exploiting direction embedded velocity components, achieve high-resolution two-dimensional (2-D) estimation result with The simulations demonstrate that offers stable compared existing non-quaternion schemes need for any pair matching between estimated azimuth and angles.