• Title/Summary/Keyword: Stepped Chirp Waveform

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Inverse Synthetic Aperture Radar Imaging Using Stepped Chirp Waveform (계단 첩 파형(Stepped Chirp Waveform)을 이용한 ISAR 영상 형성)

  • Lee, Seong-Hyeon;Kang, Min-Suk;Park, Sang-Hong;Shin, Seung-Yong;Yang, Eunjung;Kim, Kyung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.9
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    • pp.930-937
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    • 2014
  • Inverse synthetic aperture radar (ISAR) images can be generated by radar which radiates the electromagnetic wave to a target and receives signal reflected from the target. ISAR images can be widely used to target detection and recognition. This paper proposed a method of generation of high resolution ISAR images by synthesizing frequency spectrums of each stepped chirp waveform in one burst and sub-sampling in frequency domain. This process is performed over entire bursts during coherent processing interval. Conventional ISAR image generation method using stepped frequency waveform has a severe problem of short unambiguous range, loading to ghost phenomenon. However, this problem can be resolved by the proposed method. In simulations, we generate high resolution ISAR image of the moving target which is Boeing-737 aircraft model composed of several ideal point scatterers.

Inter-Pulse Motion Compensation of an ISAR Image Generated by Stepped Chirp Waveform Using Improved Particle Swarm Optimization (펄스 간 이동 성분을 갖는 계단 첩 파형의 개선된 PSO를 이용한 ISAR 영상 요동 보상)

  • Kang, Min-Seok;Lee, Seong-Hyeon;Park, Sang-Hong;Shin, Seung-Yong;Yang, Eunjung;Kim, Kyung-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.2
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    • pp.218-225
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    • 2015
  • Inverse synthetic aperture radar(ISAR) is coherent imaging system formed by conducting signal processing of received data which consists of radar cross section(RCS) reflected from maneuvering target. A novel algorithm is proposed to compensate inter-pulse motion(IPM) for the purpose of forming an well-focused ISAR image through signals generated by stepped chirp waveform( SCW). The velocity and acceleration of the target related to IPM are estimated based on particle swarm optimization (PSO) which has been widely used in optimization technique. Furthermore, a modified PSO which enables us to improve the performance of PSO is used to compensate IPM in a very short-time. Simulation results using point scatterer model of a Boeing-737 aircraft validate the performance of the proposed algorithm.