• Title/Summary/Keyword: Array Shape Estimation

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Performance Analysis of the Array Shape Estimation Methods Based on the Nearfield Signal Modeling (근거리 신호 모델링을 기반으로 한 어레이 형상 추정 기법들의 성능 분석)

  • Park, Hee-Young;Lee, Chung-Yong
    • The Journal of the Acoustical Society of Korea
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    • v.27 no.5
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    • pp.221-228
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    • 2008
  • To estimate array shape with reference sources in SONAR systems, nearfield signal modeling is required for the reference sources near a towed array. Array shape estimation method based on the nearfield signal modeling generally exploits the spatial covariance matrix of the received reference sources. Among those method, nearfield eigenvector method uses the eigenvector corresponding to the maximum eigenvalue as a steering vector of the reference source. In this paper, we propose a simplified subspace fitting method based on the nearfield signal modeling with spherical wave modeling. Furthermore, we analyze performance of the array shape estimation methods based on the nearfield signal modeling for various environments. The results of the numerical experiments indicate that the simplified subspace fitting method and the nearfield eigenvector method with single reference source shows almost similar performance. Furthermore, the simplified subspace fitting method with 2 reference sources consistently estimates the shape of the array regardless of the incident angle of the reference sources, whereas the nearfield eigenvector method cannot apply for the case of 2 reference sources.

The Performance Improvement of Towed Array Shape Estimation Using Kalman Filters (견인 어레이 형상 추정의 칼만 필터 접근 방법에 대한 성능 개선)

  • 박민수;도경철;오원천;윤대희;이충용
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.691-694
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    • 1999
  • This paper presents a performance improvement technique of 2-D towed array shape estimation using Kalman filters. The proposed algorithm by linear model approximation corrects the position errors caused by the Kalman filter results. However, since the assumed linear model makes errors at bending parts, the spline interpolation algorithm based on curve is proposed to reduce the errors.

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A Study on Three Dimensional Array Shape Calibration of the Bottom Mounted Array by Iterative Least Squares (최소자승법을 이용한 해저고정형 선배열 센서의 3차원 배열형상 추정기법 연구)

  • Choi, jae-Yong;Son, Kweon
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.5
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    • pp.370-375
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    • 2004
  • This paper proposes an algorithm that estimates three dimensional array shape calibration about the bottom-mounted sensor array. under the assumption that the active sources are in the far-field with unknown positions. Under some assumptions. we calculate the sensor positions via an algebraic solutions of a least squares problem that the linear equations are related to the sensor positions and directions or arrival. We give examples of algorithm performance from both computer simulations and sea test. We also illustrate the performance of sensor positions estimation as a function of time delay estimation variance and the distribution of the localizing sources.

Psychophysical Experiment for Shape Recognition by Vibratory Tactile Stimulated Array (진동자극배열에 의한 형상 인식의 정신물리학적 실험)

  • Yoon Myoung-Jong;Kim Nam-Gyun;Yu Kee-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.11
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    • pp.943-949
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    • 2005
  • For the psychophysical experiment of tactile perception of shapes, experimental system consists of vibrator, tactile stimulation array, measurement and control system is designed and prepared. The psychophysical experiment for the tactile perception of shape is carried out by the estimation of the subject group. Through the experiment the threshold of tactile perception to multi-stimuli with some line shape is obtained. Also the appropriate tactile stimulus intensity and frequency of the tactile stimulation array to recognize arbitrary shapes effectively are derived and discussed.

Performance Evaluation of Cascade AOA Estimation Algorithm Based on Square Array Antenna (정방배열 안테나 기반 캐스케이드 도래각 추정 알고리즘 성능평가)

  • Kim, Tae-Yun;Hwang, Suk-Seung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.6
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    • pp.1053-1060
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    • 2019
  • The satellite antenna for collecting information is mainly classified into reflector antenna, lens antenna, and phased array antenna. Among them, the phased array antenna with the excellent antenna pattern control performance for a multi-beam system is frequently used. Although the terrestrial signal information collection based on the satellite is not much effected geographically, it requires the accurate angle-of-arrival (AOA) information of the interesting signal. In this paper, we discuss the characteristics and the advantages/disadvantages of the antenna array shape employed in the phased array antenna. In addition, we present the Cascade AOA estimation algorithm based on a square array antenna mounted on the satellite receiver, and show the performance evaluation results through the computer simulation.

A method for estimating the shape of a finite cylindrical radiator from its pressure field (방사 음장을 이용한 원통형 방사체의 형상 추정)

  • Kim, Koo-Hwan;Kim, Yang-Hann
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.718-722
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    • 2014
  • A method for estimating the cylindrical shape of a sound radiator is presented. It assumes that sound field can be measured by a linear array. A sound field, due to the radiator vibrating with uniform velocity, can be determined by its shape, size, and orientations. Measured data also can be varying from the array's position. To predict the shape of radiators from these measured data, mathematical relation between geometric parameter and measured information is needed. Assume that a radiator is cylinder, the magnitude and phase of measured pressure is related with the length and diameter of radiator, respectively. In this paper, the method for estimating length and shape of a finite cylinder by using its radiated pressure is proposed and verified through experiment.

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An Experimental Study on Synthetic Aperture Sonar under Korean Littoral Environment (한국 근해에서의 실측 데이터를 이용한 합성 어퍼쳐 소나 실험에 관한 연구)

  • 박희영;도경철;강현우
    • The Journal of the Acoustical Society of Korea
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    • v.23 no.6
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    • pp.428-436
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    • 2004
  • Synthetic Aperture Sonar is a technique of extending Physically limited length of an array by signal processing to enhance bearing resolution of a system. The previous techniques estimate most or away shapes as linear. so when towed array shapes are distorted. this can create a deviation from actual situation. In this paper. we estimated perturbed away shapes. and compensated distortion by using estimated array shapes and synthesized arrays in aperture domain. As experimental data, we used the one obtained from towed array in neighboring waters of the Korean peninsula. We extended array by compensating differences in time and spatial position between overlapped subarrays by using SAS techniques. In simulation results. we confirmed that the bearing resolution was enhanced.

Adaptive Beamforming System Based on Combined Array Antenna (혼합 배열 안테나 기반의 적응 빔형성 시스템)

  • Kim, Tae-Yun;Hwang, Suk-Seung
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.1
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    • pp.9-18
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    • 2021
  • The 5G communication system employs the millimeter wave with the extremely high frequency. Since the high frequency signal has the strong straightness, the beamforming technology based on the multiple base stations is required for services covering wide range. The beamformer needs the angle-of-arrival(AOA) information of the signal incident to the antenna, and it is generally estimated through the high resolution AOA estimation algorithm such as Multiple Signal Classification (MUSIC) or Estimation of Signal Parameters via Rotational Invariacne Technique (ESPRIT). Although various antenna array shapes can be employed for the beamformer, a single shape (square, circle, or hexagonal) is typically utilized. In this paper, we introduce a transmitting/receiving beamforming system based on the combined array antenna with square and circular shapes, which is proper to various frequency signals, and evaluate its performance. For evaluating the performance of the proposed beamforming system based on the combined array antenna, we implement the computer simulation employing various scenarios.

Comparison of the Normalized SNRs between the LPA Beamformer and the Conventional Beamformer for a Moving Source

  • Seokjin Sung;Hyunduk Kang;Kim, Kiseon
    • Proceedings of the IEEK Conference
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    • 2003.07a
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    • pp.190-193
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    • 2003
  • The DOA(Direction Of Arrival) estimation to select a best beam for receiving a particular signal in switched beam antenna systems, and to shape the optimal beam in adaptive array antenna systems, is typically performed under the assumption that the target user motion is almost negligible. In this paper, we model the user as the time-varying source and adopt the LPA(Local Polynomial Approximation) tracking algorithm, proposed by Katkovnik, to solve the time-varying DOA estimation problem. Then, we compare the power spectrum functions between the LPA beamformer and the conventional beamformer, also, the normalized SNRs of each beamformer. The results show that the LPA beamformer is robuster than the conventional beamformer in tine-varying environments. In addition, in case of the conventional beamformer, more array elements give rise to more degradation in the aspect of SNR.

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Robust Beamforming Method by Linear Array Shape Estimation using Kanlman Filter (칼만필터 선배열 형상 추정에 의한 견실한 빔형성 기법 연구)

  • 한정우
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1996.06a
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    • pp.18-21
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    • 1996
  • 예인형 선배열 소나에서 기존의 선배열 빔형성 기법을 적용하면 예인함 기동시 선배열 형상 변형에 의해 심각한 성능 저하 현상이 나타난다. 이러한 문제 해결을 위해 센서배열 변형을 고려한 견실한 빔형성 기법은 선배열 형상 추정을 위해 칼만필터를 이용한 형상 추정기법을 이용하고, 변형보상 빔형성을 위해 선배열 세그먼트 기울기 추정값을 이용하는 변형보상 빔형성 알고리즘을 제안하였다. 제안된 기법을 기존의 빔형성 기법을 적용하여 시뮬레이션에 의해 제안된 기법의 보상성능을 입증 하였다.

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