• Title/Summary/Keyword: 역합성개구레이더

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Interannual Changes of Bar Morphology in the Han River Estuary Using Satellite Imagery (인공위성에 의한 한강 하구역 퇴적상 경년 변동 특성 조사)

  • Yang, Chan-Su
    • Proceedings of KOSOMES biannual meeting
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    • 2007.11a
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    • pp.57-60
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    • 2007
  • The Han River is divided into North and South Korea by NLL(Northern Limit Line) and its area has been blocked by CCL(Civil Control Line) since the Korean War in 1950. Satellite remote sensing, therefore, is uniquely suited to monitoring bar transformation in the region. In river with bar, the characteristics of its physical conditions have a close relationship with bar morphology. In this paper, a monitoring approach of bar transformation in the Han River Estuary is presented using RADARSAT/SAR images from 2000 to 2005 and spatial patterns of bar morphology are presented. It could be said that in the estuary vegetated area and natural levees are developed well, but bars are shifted after an event like a flood. It is also showed that suspended solids such as silt transported through the estuary could contribute highly to a sedimentation environment around Incheon.

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Improvement of ISAR Autofocusing Performance Based on PGA (PGA(Phase Gradient Autofocus)기반 ISAR영상 자동초점기법 성능개선)

  • Kim, Kwan Sung;Yang, Eun Jung;Kim, Chan Hong;Park, Sung Chul
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.5
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    • pp.680-687
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    • 2014
  • PGA(phase gradient autofocus) has been widely used to remove motion induced phase errors in the ISAR(inverse synthetic aperture radar) imaging. The critical process for the processing time and image quality is windowing stage in PGA. In this paper, the new method to determine window size based on polynomial least square approximation is proposed. Moreover, dominant range bins are selected for efficient phase error estimation, which improve image quality and speed up convergence. The simulation results show that the proposed algorithm provides high quality ISAR images while computational efficiency of inherent PGA is retained.

RF Seeker Measurement modeling using ISAR Image (ISAR 영상을 이용한 RF탐색기 측정치 모델링)

  • Ha, Hyun-Jong;Park, Woosung;Jung, Ki-Hwan;Park, Sang-Sup;Koh, Il-Suek;Ryoo, Chang-Kyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.1
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    • pp.40-48
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    • 2015
  • In this paper, we suggest a measurement modeling of the RF seeker using the ISAR(Inverse Synthetic Aperture Radar) image. Reference scattering points are extracted first from ISAR images which are changed according to target attitude. And then uncertainties included in RF seeker measurement such as noise strength, blink, and boresight error are added to the reference scattering points. The proposed measurement model of the RF seeker can be used to develop various kinds of target tracking algorithms.

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.

Radar Target Recognition Using a Fusion of Monostatic/Bistatic ISAR Images (모노스태틱/바이스태틱 ISAR 영상 융합을 통한 표적식별 연구)

  • Cha, Sang-Bin;Yoon, Se-Won;Hwang, Seok-Hyun;Kim, Min;Jung, Joo-Ho;Lim, Jin-Hwan;Park, Sang-Hong
    • The Journal of Korean Institute of Information Technology
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    • v.16 no.12
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    • pp.93-100
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    • 2018
  • Inverse Synthetic Aperture Radar(ISAR) image is 2-dimensional radar cross section distributions of a target. For target approaching along radar's line of sight(LOS), the bistatic ISAR can compensate for the weakness of the monostatic ISAR which can not obtain the vertical resolution of the image. However, bistatic ISAR have longer processing times and variability in scattering mechanisms than monostatic ISAR, so target identification using only bistatic ISAR images can be inefficient. Therefore, this paper analyzes target identification performance using monostatic and bistatic ISAR images of targets approaching along radar's LOS and proposes a method of target identification through fusion of two radars. Simulation results demonstrate that identification performance through fusion is more efficient than identification performance using only monostatic, bistatic ISAR images.