scholarly journals Sensitivity Analysis of a Beamforming Technique for Acoustic Measurements

2021 ◽  
Author(s):  
Pushpinder Singh Bhullar
Keyword(s):  
Linear Array ◽  
Sound Level ◽  
Acoustic Measurements ◽  
Acoustic Source ◽  
Uniform Linear Array ◽  
Random Array ◽  
Planar Array ◽  
Simulation Results ◽  
Spiral Array ◽  
Beamforming Technique

Beamforming is a technique that is used to determine the location of an acoustic source and the sound level spectrum of the signal produced by the source. This technique involves an array of microphones which record acoustic signals at multiple locations. A detailed analysis of the beamforming technique was carried out for three different array geometries: a uniform linear array, a uniform planar array, and a random array. The effect of various parameters, such as the number of microphones in an array, on the applicability of the technique was examined using both simulations and experiments. The simulation results established that the source localization capability of a uniform linear array is limited to an acoustic source lying in the plane of the array. In contrast, a planar array (either uniform or random) does not suffer the above limitation. The results also showed that a random array (eg., a spiral array) is the best of all the array geometries. The experimental results demonstrated the robustness of the beamforming technique in localizing an acoustic source and also confirmed the superiority of a uniform planar array over a uniform linear array.

scholarly journals Sensitivity Analysis of a Beamforming Technique for Acoustic Measurements

2021 ◽  
Author(s):  
Pushpinder Singh Bhullar
Keyword(s):  
Linear Array ◽  
Sound Level ◽  
Acoustic Measurements ◽  
Acoustic Source ◽  
Uniform Linear Array ◽  
Random Array ◽  
Planar Array ◽  
Simulation Results ◽  
Spiral Array ◽  
Beamforming Technique

Beamforming is a technique that is used to determine the location of an acoustic source and the sound level spectrum of the signal produced by the source. This technique involves an array of microphones which record acoustic signals at multiple locations. A detailed analysis of the beamforming technique was carried out for three different array geometries: a uniform linear array, a uniform planar array, and a random array. The effect of various parameters, such as the number of microphones in an array, on the applicability of the technique was examined using both simulations and experiments. The simulation results established that the source localization capability of a uniform linear array is limited to an acoustic source lying in the plane of the array. In contrast, a planar array (either uniform or random) does not suffer the above limitation. The results also showed that a random array (eg., a spiral array) is the best of all the array geometries. The experimental results demonstrated the robustness of the beamforming technique in localizing an acoustic source and also confirmed the superiority of a uniform planar array over a uniform linear array.

An Improved Clutter Suppression Method for Non-Sidelooking Uniform Linear Array Antennas Airborne Radar

2013 ◽  
Vol 681 ◽  
pp. 175-180
Author(s):  
Jun Zhao ◽  
Xu Hang
Keyword(s):  
Linear Array ◽  
Compensation Method ◽  
Airborne Radar ◽  
Clutter Suppression ◽  
Uniform Linear Array ◽  
Array Antennas ◽  
Compensation Methods ◽  
Suppression Method ◽  
Simulation Results ◽  
Independent Identically Distributed

The clutter distribution of airborne radar with non-sidelooking uniform linear array antennas varies with ranges and samples in different range gates are not independent identically distributed vectors, so that the statistical STAP methods degrade greatly. In this paper, an improved clutter range dependence compensation method for airborne radar with uniform linear array is proposed. This method involves in a preprocessing with ADC method to align the mainlobe of clutter spectrum in different range gates and subsequently clutter suppression in other azimuths with EDBU technology. Simulation results show the proposed method can reduce the clutter spectrum dispersion significantly and outperform conventional local compensation methods.

scholarly journals Sidelobe Suppression with Null Steering by Independent Weight Control

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Zafar-Ullah Khan ◽  
Aqdas Naveed Malik ◽  
Fawad Zaman ◽  
Syed Azmat Hussain ◽  
Abdul-Rehman Khan
Keyword(s):  
Convex Optimization ◽  
Weight Control ◽  
Linear Array ◽  
Sidelobe Suppression ◽  
Uniform Linear Array ◽  
Null Steering ◽  
Simulation Results

A uniform linear array ofnantenna elements can steer up ton-1nulls. In situations where less thann-1nulls are required to be steered, the existing algorithms have no criterion to utilize the remaining weights for sidelobe suppression. This work combines sidelobe suppression capability with null steering by independent weight control. For this purpose, the array factor is transformed as the product of two polynomials. One of the polynomials is used for null steering by independent weight control, while the second one is for sidelobe suppression whose coefficients or weights are determined by using convex optimization. Finally, a new structure is proposed to incorporate the product of two polynomials such that sidelobe suppression weights are decoupled from those of null steering weights. Simulation results validate the effectiveness of the proposed scheme.

Locating Point of Impact on an Anisotropic Cylindrical Surface Using Acoustic Beamforming Technique

2013 ◽  
Vol 558 ◽  
pp. 331-340 ◽  
Author(s):  
Hayato Nakatani ◽  
Talieh Hajzargarbashi ◽  
Kaita Ito ◽  
Tribikram Kundu ◽  
Nobuo Takeda
Keyword(s):  
Wave Speed ◽  
Linear Array ◽  
Composite Shell ◽  
Lamb Waves ◽  
Acoustic Source ◽  
Optimization Scheme ◽  
Maximum Value ◽  
Cylindrical Composite Shell ◽  
The Impact ◽  
Beamforming Technique

A beamforming array technique with four sensors is applied to a cylindrical geometry for detecting point of impact. A linear array of acoustic sensors attached to the plate record the waveforms of Lamb waves generated at the impact point with individual time delay. A beamforming technique in conjunction with an optimization scheme that incorporates the direction dependent guided Lamb wave speed in cylindrical plates is developed. The optimization is carried out using the experimentally obtained wave speed as a function of propagation direction. The maximum value in the beamforming plot corresponds to the predicted point of impact. The proposed technique is experimentally verified by comparing the predicted points with the exact points of impact on a cylindrical aluminum plate and a cylindrical composite shell. For randomly chosen points of impact the beamforming technique successfully predicts the location of the acoustic source.

scholarly journals DOA Estimation for Mixed Uncorrelated and Coherent Sources in Multipath Environment

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Heping Shi ◽  
Wen Leng ◽  
Anguo Wang ◽  
Tongfeng Guo
Keyword(s):  
Linear Array ◽  
Estimation Method ◽  
Doa Estimation ◽  
Spatial Smoothing ◽  
Uniform Linear Array ◽  
Performance Simulation ◽  
Coherent Sources ◽  
Multipath Environment ◽  
Simulation Results ◽  
Effectiveness And Efficiency

A novel direction-of-arrival (DOA) estimation method is proposed to cope with the scenario where a number of uncorrelated and coherent narrowband sources simultaneously impinge on the far-field of a uniform linear array (ULA). In the proposed method, the DOAs of uncorrelated sources are firstly estimated by utilizing the property of the moduli of eigenvalues of the DOA matrix. Afterwards, the contributions of uncorrelated sources and the interference of noise are eliminated completely by exploiting the improved spatial differencing technique and only the coherent components remain in the spatial differencing matrix. Finally, the remaining coherent sources can be resolved by performing the improved spatial smoothing scheme on the spatial differencing matrix. The presented method can resolve more number of sources than that of the array elements and distinguish the uncorrelated and coherent sources that come from the same direction as well as improving the estimation performance. Simulation results demonstrate the effectiveness and efficiency of the proposed method.

scholarly journals Off-Grid DoA Estimation on Non-Uniform Linear Array Using Constrained Hermitian Matrix

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5775
Author(s):  
Hyeonjin Chung ◽  
Jeungmin Joo ◽  
Sunwoo Kim
Keyword(s):  
Toeplitz Matrix ◽  
Linear Array ◽  
Hermitian Matrix ◽  
Estimation Algorithm ◽  
Doa Estimation ◽  
Estimation Accuracy ◽  
Uniform Linear Array ◽  
Atomic Norm ◽  
Array Structures ◽  
Simulation Results

In this paper, an off-grid direction-of-arrival (DoA) estimation algorithm which can work on a non-uniform linear array (NULA) is proposed. The original semidefinite programming (SDP) representation of the atomic norm exploits a summation of one-rank matrices constructed by atoms, where the summation of one-rank matrices equals a Hermitian Toeplitz matrix when using the uniform linear array (ULA). On the other hand, when the antennas in the array are placed arbitrarily, the summation of one-rank matrices is a Hermitian matrix whose diagonal elements are equivalent. Motivated by this property, the proposed algorithm replaces the Hermitian Toeplitz matrix in the original SDP with the constrained Hermitian matrix. Additionally, when the antennas are placed symmetrically, the performance can be enforced by adding extra constraints to the Hermitian matrix. The simulation results show that the proposed algorithm achieves higher estimation accuracy and resolution than other algorithms on both array structures; i.e., the arbitrary array and the symmetric array.

Configuration of Random Transducer Array in Irregular Region Based on Delaunay Triangulation

2010 ◽  
Vol 29-32 ◽  
pp. 1085-1090
Author(s):  
Shi Lin Wu ◽  
Qi Zhang ◽  
Zhi Ping Huang
Keyword(s):  
Delaunay Triangulation ◽  
Linear Array ◽  
Minimum Variance ◽  
Uniform Linear Array ◽  
Transducer Array ◽  
Irregular Region ◽  
Random Array ◽  
Minimum Variance Distortionless Response ◽  
Uniform Plane ◽  
Better Than

To realize the configuration of a cymbal transducer array in an irregular region, Delaunay triangulation is adopted to mesh the irregular region and the vertices of the Delaunay triangular mesh are regarded as the positions of the array elements. In this way, a random array of cymbal transducers is formed. Minimum Variance Distortionless Response (MVDR) beamformer is used to optimize the beam of the random array, and the directivity simulation is carried out in MATLAB. The results show that the directivity of the random array within the irregular region is better than that of the uniform linear array and that of the uniform plane array configured in the same region.

An Elevation Cosine Derivation Based Updating STAP Method for Non-Sidelooking Uniform Linear Array

2014 ◽  
Vol 556-562 ◽  
pp. 3662-3665
Author(s):  
Xing Hui Chen ◽  
Shi Qiao Gao
Keyword(s):  
Linear Array ◽  
Airborne Radar ◽  
Uniform Linear Array ◽  
Array Antennas ◽  
Compensation Methods ◽  
Simulation Results ◽  
Independent Identically Distributed

The clutter distribution of airborne radar with non-sidelooking uniform linear array antennas varies with ranges and interference in different range gates are not independent identically distributed vectors, so the performance of statistical STAP methods degrade heavily. In this paper, the range dependency problem is studied and a clutter nonstationarity reducing method is proposed. This method involves in the pre-processing of elevation cosine based vector extending and subsequently statistical STAP technique. Simulation results show the proposed method can reduce the clutter dispersion significantly and outperform conventional compensation methods.

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.

scholarly journals Polarized Uniform Linear Array System: Beam Radiation Pattern, Beamforming Diversity Order, and Channel Capacity

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Xin Su ◽  
KyungHi Chang
Keyword(s):  
Radiation Pattern ◽  
Channel Capacity ◽  
Linear Array ◽  
Outdoor Environment ◽  
Channel Gain ◽  
Diversity Order ◽  
Uniform Linear Array ◽  
Beam Radiation ◽  
Antenna Polarization ◽  
Beamforming Technique

There have been many studies regarding antenna polarization; however, there have been few publications on the analysis of the channel capacity for polarized antenna systems using the beamforming technique. According to Chung et al., the channel capacity is determined by the density of scatterers and the transmission power, which is obtained based on the assumption that scatterers are uniformly distributed on a 3D spherical scattering model. However, it contradicts the practical scenario, where scatterers may not be uniformly distributed under outdoor environment, and lacks the consideration of fading channel gain. In this study, we derive the channel capacity of polarized uniform linear array (PULA) systems using the beamforming technique in a practical scattering environment. The results show that, for PULA systems, the channel capacity, which is boosted by beamforming diversity, can be determined using the channel gain, beam radiation pattern, and beamforming diversity order (BDO), where the BDO is dependent on the antenna characteristics and array configurations.

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