• 제목/요약/키워드: Perfectly reflecting sphere

검색결과 3건 처리시간 0.018초

Analytical approximation of optical force on a perfectly reflecting sphere: ray-optics regime

  • Kim, Sang Bok;Song, Dong Keun
    • 한국입자에어로졸학회지
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    • 제14권1호
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    • pp.1-8
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    • 2018
  • The optical force on a perfectly reflecting sphere in a ray-optics regime is considered. With the assumption of geometric optics and a sphere smaller than the minimum waist of the illuminating beam, closed-form analytic expressions of the optical force are derived. Both axial and radial forces are expressed by a modified Bessel function of the first kind. The derived analytic expressions are compared to precise numerical computations of the exact optical force equations derived previously. In addition the error due to the small sphere assumption is estimated analytically.

곡면패치 물리광학법을 이용한 곡면체의 RCS 및 TES 계산 (Computation of RCS and TES of Curved Objects Using a Curved-Patch Physical Optics Method)

  • 부성윤
    • 대한조선학회논문집
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    • 제38권1호
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    • pp.62-71
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    • 2001
  • 레이다 반사면적(RCS)은 레이더 탐지에, 그리고 음향 표적강도(TES)는 소나 탐지에 직접 관련이 있기 때문에 이 두 신호는 함정설계 초기단계에서 검토되어야 하는 중요한 요소 중의 하나이다. 따라서 본 연구에서는 곡면패치 물리광학법을 도입하여 완전반사 곡면구조물의 RCS와 TES를 계략적으로 예측하는 기법을 개발하였다. 수치기법의 검증을 위하여 원형 실린더, 구, NACA3317 날개의 RCS를 계산한 후 가용한 자료와 비교 검토하였다. 또한 본 연구의 기법을 잠수함에 확장 적용하여 수상 항해시의 RCS와 잠수 항해시의 TES를 각각 계산하였다. 그리고 레이더 파와 소나 음파의 입사방위와 고각에 따른 주요 반사구조물의 위치를 확인하였다.

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형상요소분석을 통한 레이더단면적의 추정 (An Estimation of RCS through Configuring Element Analysis)

  • 권태준;신보현
    • 한국군사과학기술학회지
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    • 제15권4호
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    • pp.417-423
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    • 2012
  • Radar Cross Section(RCS) is a measure of how detectable an object is with a radar. A larger RCS indicates that an object is more easily detected. Informally, the RCS of an object is the cross-sectional area of a perfectly reflecting sphere that would produce the same amount of reflection strength as the object in question would. In order to estimate RCS of aircraft weapons the external surface is modeled as a collection of simple shape elements. And the overall RCS is estimated as a vector sum of configuring elements' cross-sections which are well known given by analytic formulae. A RCS estimation code is developed for a typical shape of Air-To-Surface bombs and missiles. Size of weapons and location of fins are implemented in the code in addition to the presence of canards. The ability to predict radar return from flying vehicles becomes a critical technology issue in the development of stealth configurations. This simplified method of RCS estimation is known to be fast and accurate enough in an optical region of high frequency incident radio wave.