The Journal of Korean Institute of Electromagnetic Engineering and Science (한국전자파학회논문지)

The Korean Institute of Electromagnetic Engineering and Science (한국전자파학회)
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A Study on the Rotational Motion Compensation Method for ISAR Imaging

ISAR 영상 형성을 위한 회전운동보상 기법 연구

  • Kang, Byung-Soo (Department of Electronic Engineering, Pohang University of Science and Technology) ;
  • Bae, Ji-Hoon (Department of Electronic Engineering, Pohang University of Science and Technology) ;
  • Chung, Sung-Eun (Department of Electronic Engineering, Pohang University of Science and Technology) ;
  • Kim, Chan-Hong (Agency for Defense Development) ;
  • Kim, Kyung-Tae (Department of Electronic Engineering, Pohang University of Science and Technology)
  • 강병수 (포항공과대학교 전자공학과) ;
  • 배지훈 (포항공과대학교 전자공학과) ;
  • 정성은 (포항공과대학교 전자공학과) ;
  • 김찬홍 (국방과학연구소) ;
  • 김경태 (포항공과대학교 전자공학과)
  • Received : 2015.10.07
  • Accepted : 2015.12.24
  • Published : 2016.01.31
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Abstract

In this paper, we propose a inverse synthetic aperture radar(ISAR) rotational motion compensation(RMC) method to remove residual blurring caused by non-uniform rotational motion of a target. First, a range bin having an isolated scatterer is selected. Next, polynomial phase signal in the selected range bin is estimated by using both Fourier transform(FT) and polynomial-phase transform(PPT). Finally, a new slow time variable that uniformly samples radar signal along the aspect angle directions is defined by using the estimated phase signal, and we interpolate radar signal in terms of the new time variable. As a result, rotational motion to blurr ISAR images is removed, and focused ISAR images are obtained. Simulation results using battleship model validate the robustness and effectiveness of our proposed RMC method.

본 논문에서는 표적의 관측각도 변화율이 일정하지 않은 표적의 회전운동 성분의 결과로 인한, 역합성 개구면 레이다(Inverse Synthetic Aperture Radar: ISAR) 영상의 초점 저하 현상을 해결하는 회전운동보상(Rotational Motion Compensation: RMC) 기법을 제안한다. 먼저, 하나의 산란원이 존재하는 레인지 빈(range bin)을 선택한다. 다음으로, 퓨리에 변환(Fourier Transform: FT)과 다항식-위상 변환(Polynomial-Phase Transform: PPT)를 활용하여, 선택된 레인지 빈에 대한 위상함수를 추정한다. 마지막으로, 관측 각도의 변화율을 일정하게 하는 새로운 시간 변수를 정의한 후, 보간법(interpolation)을 통해 새롭게 정의된 시간변수에 대한 레이다 신호를 획득한다. 이에 대한 결과로, 관측 각도의 변화율을 일정하지 않게 하는 표적의 회전운동 성분을 제거함으로써, 초점이 맞는 ISAR 영상을 획득할 수 있다. 전함(battleship) 모델을 사용한 시뮬레이션을 통해 본 논문에서 제안된 RMC 기법의 효용성을 검증하였다.

Keywords

References

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