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Studies on the Effects of Random Irregularities of Medium on Radars

Research Project

Project/Area Number 02650248
Research Category

Grant-in-Aid for General Scientific Research (C)

Allocation TypeSingle-year Grants
Research Field 電子通信系統工学
Research InstitutionKyushu University

Principal Investigator

TATEIBA Mitsuo  Kyushu University Faculty of Engineering Professor, 工学部, 教授 (40037924)

Co-Investigator(Kenkyū-buntansha) NANBU Yukihisa  Sasebo College of Technology Electrical Engineering Lecturer, 電気工学科, 講師 (00228115)
KUDO Takato  Kyushu University Faculty of Engineering Research Associate, 工学部, 助手 (60225159)
Project Period (FY) 1990 – 1991
Project Status Completed (Fiscal Year 1991)
Budget Amount *help
¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1991: ¥700,000 (Direct Cost: ¥700,000)
KeywordsRandom Media / Backscattering Enhancement / Scattering Theory / Pulse Spread / Image Resolution / Holographic Radars / Medium Effects / Effective Dielectric Constant / ランダム媒基 / 後方散乱 / 強調現象 / 多重散乱
Research Abstract

This project is
1. to present a theory of wave scattering from a target in random media,
2. to formulate (2-1) the-scattering cross-section of a conducting cylinder in turbulent media, (2-2) the mean pulse waveform of received waves in a FM chirp radar, which waves passed through turbulence, (2-3) the reconstructed image in holographic radars, and (2-4) the iiacroscopic characteristics of discrete random media,
3. to analyze (2-1) to (2-4) numerically for some practical models and make clear the effects of random irregularities.
Subject 1 :
We present a general method applicable to most practical cases, by which method the wave scattering can be exactly analyzed as boundary value problems for a conducting target of arbitrary shape and size. That is, it can be solved through two independent analyses of current generators on the target in free space and of wave propagation in random media.
Subject 2 and 3 :
(3-1) In strong turbulence, the backscattering cross-section sigma becomes about two times compared with sigma in free space if the spatial coherence length l of waves on the target is very larger than the size a of target, but sigma takes very large values at the frequency bands close to the internal resonance frequencies of target. (3-2) A FM chirp radar system, one of satellite microwave sensing systems, is insusceptible to the atmospheric turbulence and the ionospheric turbulence. (3-3) Holographic images smeared due to turbulence can be reconstructed with negligible distortion by a spatial filtering of amplitudes of received waves. (3-4) The condition for many dielectric spheres to be randomly distributed for coherent waves is presented, and the effective dielectric constant and the coherence attenuation rate are precisely analyzed compared with the conventional results.

Report

(3 results)
  • 1991 Annual Research Report   Final Research Report Summary
  • 1990 Annual Research Report
  • Research Products

    (24 results)

All Other

All Publications (24 results)

  • [Publications] M.Tateiba,K.Fujisaki: "Analysis of turbulent medium effects on holographic image resolution in airborne radar" Proc.Japan-China Joint Meeting on OFSET. EMT-90-58. 97-104 (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] M.Tateiba: "The Lorentz recciprocity in random-media-The derivation from Maxwll's equations" Raido Science. 26. 499-503 (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] M.Tateiba,Y.Nanbu: "The condition for the distribution of dielectric cylinders to be random-The derivation from the anlysis f coherent fields" IEICE Transaction. E74. 1055-1058 (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] M.tateiba,E.Tomita: "Coherent eletromagnetic waves scattered from a conducting cylinder surrounded by turbulent media" IEICE Transaction. E74. 1288-1292 (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] 立居場 光生,南部 幸久: "コヒ-レント界において多数の誘電体円柱の配置がランダムとみなせるための条件の数値解析" 九州大学工学集報. 64. 463-469 (1991)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] M.Tateiba,E.Tomita: "Theory of scalar wave scattering from a conducting target in random media" IEICE Transation,Electronics. E75-C. 101-106 (1992)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] M. Tateiba and K. Fujisaki: "Analysis of turbulent medium effects on holographic image resolution in airborne radar" Proc. Japan-China Joint Meeting on OFSET. EMT-90-58. 97-104 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] M. Tateiba: "The Lorentz reciprocity in random media - The derivation from Maxwell's equations" Radio Science. 26. 499-503 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] M. Tateiba and Y. Nanbu: "The condition for the distribution of dielectric cylinders to be random - The derivation from the analysis of coherent fields" IEICE Trans.E74. 1055-1058 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] M. Tateiba and E. Tomita: "Coherent electromagnetic waves scattered from a conducting cylinder surrounded by turbulent media" IEICE Trans.E74. 1288-1292 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] M. Tateiba and Y. Nanbu: "Numerical analysis of conditions for distribution of dielectric cylinders to be random for coherent waves" Tech. Reports Kyushu Univ.64. 463-469 (1991)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] M. Tateiba and E. Tomita: "Theory of scalar wave scattering from a conducting target in random media" IEICE Trans. Electronics. E75-C. 101-106 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1991 Final Research Report Summary
  • [Publications] 立居場 光生,藤崎 清孝: "空間フィルタリングによるホログラフィックレ-ダ-解像度の向上に関する研究" 電気学会電磁界理論研究会資料. EMTー91ー98. 31-40 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] 立居場 光生,鹿倉 義一: "乱流媒質に囲まれた導体内柱の共振領域における後方散乱断面積" 電気学会電磁界理論研究会資料. EMTー91ー137. 39-46 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] 立居場 光生,高山 一生,南部 幸久: "コヒ-レント果において多数の誘電体球の配置がランダムとみなせるための条件" 電気学会電磁界理論研究会資料. EMTー91ー138. 41-56 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] 立居場 光生,南部 幸久: "コヒ-レント界において多数の誘電体円柱の配置がランダムとみなせるための条件の数値解析" 九州大学工学集報. 64. 463-469 (1991)

    • Related Report
      1991 Annual Research Report
  • [Publications] M.Tateiba,E.Tomita: "Theory of scalar wave scattering from a conducting target in random media" IEICE Trans.Electron.E75ーC. 101-106 (1992)

    • Related Report
      1991 Annual Research Report
  • [Publications] M.Tateiba,K.Fujisaki: "Analysis of pulse distortion due to ionospheric turbulence in FM chirp radar systems" Proc.1992 Int.Symp.on Antennas and Propagation. (1992)

    • Related Report
      1991 Annual Research Report
  • [Publications] 立居場 光生;藤崎 清孝: "ホログラフィックレ-ダ再生像への大気乱流の影響の解析" 電子情報通信学会技術研究報告. SANE90ー49. 39-44 (1990)

    • Related Report
      1990 Annual Research Report
  • [Publications] 立居場 光生;藤崎 清孝: "空間フィルタリングによるホログラフィックレ-ダ解像度の向上について(I)" 電子情報通信学会技術研究報告. A・P90ー107. 83-90 (1991)

    • Related Report
      1990 Annual Research Report
  • [Publications] 立居場 光生;富田 英一;鹿倉 義一: "乱流媒質に囲まれた導体円柱の散乱断面積" 電子情報通信学会技術研究報告. A・P90ー124. 57-62 (1991)

    • Related Report
      1990 Annual Research Report
  • [Publications] M.Tateiba;Y.Nanbu: "The condition for the distribution of dielectric cylinders to be randomーthe derivation from the analysis of coherent fields" 電子情報通信学会論文誌. (1991)

    • Related Report
      1990 Annual Research Report
  • [Publications] M.Tateiba;E.Tomita;Y.Kakura: "Analysis of backscattering crossーsection of a conducting cylinder surrounded by turbulent media" Proc.of 1991 Progress in Electromagnetic Research Symposium. (1991)

    • Related Report
      1990 Annual Research Report
  • [Publications] M.Tateiba;E.Tomita: "Coherent electromagnetic waves scattered from a conducting cylinder surrounded by turbulent media" 電子情報通信学会論文誌. (1991)

    • Related Report
      1990 Annual Research Report

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Published: 1991-04-01   Modified: 2016-04-21  

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