scholarly journals A Velocity-Independent DOA Estimator of Underwater Acoustic Signals Via An Arbitrary Cross-Linear Nested Array

2021 ◽  
Author(s):  
Gengxin Ning ◽  
Yu Wang ◽  
Guangyu Jing ◽  
Xuejin Zhao
Keyword(s):  
Linear Array ◽  
Doa Estimation ◽  
Acoustic Velocity ◽  
Arbitrary Angle ◽  
Practical Applications ◽  
Estimation Algorithms ◽  
Underwater Environment ◽  
Geometric Relation ◽  
The Cross ◽  
Improved Performance

Abstract In this paper, an estimator for underwater DOA estimation is proposed by using a cross-linear nested array with arbitrary cross angle. The estimator excludes the variation acoustic velocity by deriving the geometric relation of the cross-linear array on the proposed algorithm. Therefore, compared with traditional DOA estimation algorithms via linear array, this estimator eliminates systematic errors caused by the uncertainty factor of the acoustic velocity in the underwater environment. Compared with the traditional acoustic velocity independent algorithm, this estimator uses the nested array and improves the performance of DOA estimation. In addition, the estimator is based on arbitrary angle of the cross-linear array, so it is more flexible in practical applications. Numerical simulations are provided to validate the analytical derivations and corroborate the improved performance in underwater environments where the actual acoustic velocity is not accurate.

scholarly journals Fast DOA Estimation Algorithms for Sparse Uniform Linear Array With Multiple Integer Frequencies

IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 29952-29965 ◽  
Author(s):  
Aihua Liu ◽  
Xin Zhang ◽  
Qiang Yang ◽  
Weibo Deng
Keyword(s):  
Linear Array ◽  
Doa Estimation ◽  
Uniform Linear Array ◽  
Estimation Algorithms

DOA Estimation of Noncircular Signals for Coprime Linear Array via Polynomial Root-Finding Technique

2020 ◽  
pp. 2150028
Author(s):  
Hui Zhai ◽  
Zheng Li ◽  
Xiaofei Zhang
Keyword(s):  
Linear Array ◽  
Doa Estimation ◽  
Music Algorithm ◽  
Uniform Linear Array ◽  
Estimation Algorithms ◽  
Root Finding ◽  
Noncircular Signals ◽  
Peak Search ◽  
Simulation Results ◽  
Polynomial Root Finding

In this paper, we investigate the direction of arrival (DOA) estimation problem of noncircular signals for coprime linear array (CLA). From the perspective of the CLA as extracted from a filled uniform linear array (ULA), a noncircular root-MUSIC algorithm is proposed to estimate the DOA which can avoid the spectral peak search and lower the computational complexity. Due to the noncircular characteristic, the proposed algorithm enables to resolve more sources than sensors. Meanwhile, the proposed algorithm has better angle estimation performance than some conventional DOA estimation algorithms. Numerical simulation results illustrate the performance of the proposed method.

DOA Estimation for Uniform Linear Array with Compressive Sensing

2015 ◽  
Vol 713-715 ◽  
pp. 1239-1243
Author(s):  
Ying Zhang ◽  
Guang Yao Xin ◽  
Xiao Fei Zhang
Keyword(s):  
Compressive Sensing ◽  
Linear Array ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Estimation Algorithm ◽  
Doa Estimation ◽  
Signal To Noise ◽  
Uniform Linear Array ◽  
High Demand ◽  
Estimation Algorithms

This paper discusses that the application of compressive sensing in direction of arrival (DOA) estimation. Traditional DOA estimation algorithms, such as MUSIC, ESPRIT, have shortcomings of high demand of initialization and sufficient number of snapshots and high sensitivity to signal-to-noise ratio (SNR). The proposed DOA estimation algorithm via OMP method based on compressed sensing (CS) can solve the above-mentioned problem and has good estimation performance. Computer simulations verify the effectiveness of the OMP algorithm.

Comparison between DOA Estimation Subspace methods for incoherent and coherent signals

2015 ◽  
Vol 1 ◽  
pp. 18
Author(s):  
Ahmed Abdalla ◽  
Suhad Mohammed ◽  
Tang Bin ◽  
Jumma Mary Atieno ◽  
Abdelazeim Abdalla
Keyword(s):  
Linear Array ◽  
Doa Estimation ◽  
Far Field ◽  
Matlab Simulation ◽  
Subspace Methods ◽  
Coherent Signals ◽  
Uniform Linear Array ◽  
Pros And Cons ◽  
Basic Concepts ◽  
And Performance

This paper considers the problem of estimating the direction of arrival (DOA) for the both incoherent and coherent signals from narrowband sources, located in the far field in the case of uniform linear array sensors. Three different methods are analyzed. Specifically, these methods are Music, Root-Music and ESPRIT. The pros and cons of these methods are identified and compared in light of different viewpoints. The performance of the three methods is evaluated, analytically, when possible, and by Matlab simulation. This paper can be a roadmap for beginners in understanding the basic concepts of DOA estimation issues, properties and performance.

Direction of Arrival Estimation Under Near-Field Interference Using Matrix Filter

2015 ◽  
Vol 23 (04) ◽  
pp. 1540007 ◽  
Author(s):  
Guolong Liang ◽  
Wenbin Zhao ◽  
Zhan Fan
Keyword(s):  
Near Field ◽  
Direction Of Arrival ◽  
Doa Estimation ◽  
Direction Of Arrival Estimation ◽  
Far Field ◽  
Data Simulation ◽  
Estimation Algorithms ◽  
Simulation Results

Direction of arrival (DOA) estimation is of great interest due to its wide applications in sonar, radar and many other areas. However, the near-field interference is always presented in the received data, which may result in degradation of DOA estimation. An approach which can suppress the near-field interference and preserve the far-field signal desired by using a spatial matrix filter is proposed in this paper and some typical DOA estimation algorithms are adjusted to match the filtered data. Simulation results show that the approach can improve capability of DOA estimation under near-field inference efficiently.

Improved Diffuser/Volute Combinations for Centrifugal Compressors

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
T. Steglich ◽  
J. Kitzinger ◽  
J. R. Seume ◽  
R. A. Van den Braembussche ◽  
J. Prinsier
Keyword(s):  
Cross Sections ◽  
Pressure Ratio ◽  
Pressure Rise ◽  
Outer Radius ◽  
Inner Radius ◽  
Pressure Pipeline ◽  
The Cross ◽  
Improved Performance ◽  
High Pressure Pipeline ◽  
Original Configuration

Internal volutes have a constant outer radius, slightly larger than the diffuser exit radius, and the circumferential increase of the cross section is accommodated by a decrease of the inner radius. They allow the design of compact radial compressors and hence are very attractive for turbochargers and high-pressure pipeline compressors, where small housing diameters have a favorable impact on weight and cost. Internal volutes, however, have higher losses and lower pressure rise than external ones, in which the center of the cross sections is located at a larger radius than the diffuser exit. This paper focuses on the improvement of the internal volute performance by taking into account the interaction between the diffuser and the volute. Two alternative configurations with enhanced aerodynamic performance are presented. The first one features a novel, nonaxisymmetric diffuser̸internal volute combination. It demonstrates an increased pressure ratio and lower loss over most of the operating range at all rotational speeds compared with a symmetric diffuser̸internal volute combination. The circumferential pressure distortion at off design operation is slightly larger than in the original configuration with a concentric vaneless diffuser. Alternatively, a parallel-walled diffuser with low-solidity vanes and an internal volute allows a reduction of the unsteady load on the impeller and an improved performance, approaching that of a vaneless concentric diffuser with a large external volute.

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