Acoustic Velocity-Independent 2-D DOA Estimation for Underwater Application

In this paper,an acoustic velocityindependent two-dimensional direction of arrival(2-D DOA)estimation for underwater application is presented to eliminate the effect of the inaccurate acoustic velocity estimation.According to the geometric relationship between the linear arrays,the proposed method employs the cross correlation matrix(CCM)of the data received by three crossed linear arrays to remove the acoustic velocity factor.The simulation results demonstrate that the proposed method is not susceptible to the acoustic velocity.For a single source,the proposed method outperforms the conventional method in all conditions.For multiple sources,there is a little performance degradation for the proposed method compared with the conventional method.However,the proposed method displays a better performance than the conventional method in situations where the signal to noise ratio(SNR)is extremely low or the acoustic velocity estimation error is non-negligible.Furthermore,the computational complexity of the proposed method is lower than that of the conventional method using the same amount of sensors in total,while the performance is still acceptable.

1D Acoustic Velocity-Independent DOA Estimation Method with Arbitrary Arrays

The performance of conventional direction of arrival(DOA)method is greatly affected by the uncertainty of wave velocity in underwater environment.To solve this problem,an acoustic velocity-independent method is proposed to estimate the underwater DOA using two arbitrary intersecting uniform linear arrays in this study.By introducing the additional array compared to the conventional DOA methods,the proposed algorithm can make its performance independent of the acoustic velocity through the geometric relationship between those two arrays.The simulation results demonstrate that the proposed method is more accurate and robust than other methods in an unknown sound velocity.