• Title/Summary/Keyword: GMTI

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Analysis of SAR Processing Performances with FJB Waveforms (FJB 파형을 이용한 SAR 영상 생성 기법 분석)

  • Kim, Eun-Hee;Roh, Ji-Eun;Park, Joon-Yong;Kim, Soo-Bum
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.3
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    • pp.195-207
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    • 2017
  • Recently, the SAR-GMTI mode is becoming increasingly essential in airborne radar systems. While SAR requires wideband waveforms for high resolution imaging, GMTI requires narrowband waveforms for doppler processing, which makes general LFM waveforms difficult to use for SAR-GMTI. This paper analyses the FJB(Frequency Jump Burst) waveform, which is studied for the SAR-GMTI waveform, and presents the method for the pulse compression and SAR image formation using FJB waveforms. Simulation results show that there is little difference in performances between the FJB waveform and the LFM waveform.

Application Design and Performance Analysis Simulation of Sigma-Delta STAP for GMTI Mode of Airborne Radar (항공기 레이다의 GMTI 모드를 위한 Sigma-Delta STAP의 적용 설계와 성능 분석 시뮬레이션)

  • Kim, Tae-Hyung;Yoon, Jong-Suk;Jung, Jae-Hoon;Ryu, Seong-Hyun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.4
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    • pp.336-346
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    • 2017
  • Applications of Sigma-Delta STAP, and a method of GMTI processing are presented for GMTI(Ground Moving Target Indication) mode of airborne radar with sigma, delta, and guard channels. We showed results of performance analyses of presented methods by clutter simulation with ICM(Internal Clutter Motion), signal processing simulation and MDV(Minimum Detectable Velocity). Presented methods for Sigma-Delta STAP and GMTI processing are easy to apply practically in GMTI mode of airborne radar without restriction by specific airborne radar system.

GMTI Two Channel Raw Data Processing and Analysis (GMTI 2채널 원시데이터 처리 및 분석)

  • Kim, So-Yeon;Yoon, Sang-Ho;Shin, Hyun-Ik;Youn, Jae-Hyuk;Kim, Jin-Woo;You, Eung-Noh
    • Korean Journal of Remote Sensing
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    • v.34 no.6_1
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    • pp.847-855
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    • 2018
  • GMTI (Ground Moving Target Indicator) is a kind of airborne radar function that is used widely in military applications to detect the moving targets on the ground. In this paper, GMTI signal processing technique was presented and its performance was verified using sum and difference channels raw data obtained by the captive flight test.

Target Position Correction Method in Monopulse GMTI Radar (GMTI 표적의 위치 보정 방법)

  • Kim, So-Yeon
    • Korean Journal of Remote Sensing
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    • v.36 no.3
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    • pp.441-448
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    • 2020
  • GMTI (Ground Moving Target Indication) radar system can detect ground moving targets and can provide position and velocity information of each target. However, the azimuth position of target has some offset because of the hardware errors such as mechanical tolerances. In this case, an error occurs no matter how accurate the monopulse ratio is. In this paper, target position correction method in azimuth direction has been proposed. The received sum and difference signals of monopulse GMTI system are post-processed to correct the target azimuth angle error. This method is simple and adaptive for nonhomogeneous area because it can be implemented by using only software without any hardware modification or addition.

Demonstration of Optimizing the CFAR Threshold for Development of GMTI System (GMTI 시스템 개발을 위한 CFAR 임계치 최적화)

  • Kim, So-Yeon;Yoon, Sang-Ho;Shin, Hyun-Ik
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.2
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    • pp.141-146
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    • 2018
  • The Ground Moving Target Indication(GMTI) technique can detect the moving targets on land using its Doppler returns. Also, the GMTI system can work in night regardless of the weather condition because it is an active sensor that uses the electromagnetic waves as its source. In order to develop the GMTI system, Constant False Alarm Rate(CFAR) threshold optimization is important because the main performances like detection probability, false alarm rate and Minimum Detectable Velocity(MDV) are related deeply with CFAR threshold. These key variables are used to calculate CFAR threshold and then trade-off between the variables is performed. In this paper, CFAR threshold optimization procedures are introduced, and the optimization results are demonstrated.

Ground Moving Target Displacement Compensation and Performance Analysis in the DPCA Based SAR-GMTI System (DPCA 기법을 이용한 SAR-GMTI 시스템에서 지상 이동 표적 오차 보상 기법 및 성능 분석)

  • Jung, Jae-Hoon;Jung, Jung-Soo;Jung, Chul-Ho;Kwag, Young-Kil
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.11
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    • pp.1138-1144
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    • 2009
  • The velocity and acceleration of the ground moving target can cause the target position to be displaced and defocused in the SAR image. In this paper, the displacement compensation scheme is presented to correct the displaced position and defocused moving target image in the DPCA based SAR-GMTI system. The influence of the ground moving target due to the velocity and acceleration is analyzed in range and azimuth directions, and its compensation method is presented with the simulation results. The performance of the proposed method is compared with respect to the estimated velocity and defocused quantity in both range and azimuth directions.

SAR-GMTI 기술의 원리

  • Jeon, Ju-Hwan
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.6
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    • pp.68-79
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    • 2011
  • 본 논문은 tutorial로서 synthetic aperture radar(SAR) 및 ground moving target indicator(GMTI)의 원리 및 이들이 왜 함께 사용되어야 하는지를 설명하고자 한다. 우선 SAR의 영상 형성 방법을 설명하고, 지상에서 움직이는 점 표적(point target)이 SAR 영상에서 어떻게 나타나는지를 이해하고, 마지막으로 GMTI 목적으로 사용될 수 있는 space-time adaptive processing(STAP)의 기본원리를 소개한다. 최신기술 동향은 생략하고 기본원리만 깊이 다루고자 한다.

Preliminary Simulation on Spaceborne Sparse Array Millimeter Wave Radar for GMTI

  • Kang, Xueyan;Zhang, Yunhua
    • Journal of electromagnetic engineering and science
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    • v.10 no.4
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    • pp.322-327
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    • 2010
  • Spaceborne sparse array radar for ground moving targets indication (GMTI) has outstanding advantage over full array radar for constructing ultra-large aperture. Rapid development of millimeter wave (MMW) technology make it possible for realizing MMW GMTI radar, which is much more sensitive to slow moving ground target. The paper presented the system model of a multi-carrier frequency sparse array MMW radar as well as preliminary simulation results, which showed future application of the system is very promising.

Omni Scanning DPCA using Two Passive Antennas with Vertical Separation

  • Kim Man-Jo;Kho Bo-Yeon;Yoon Sang-Ho
    • Korean Journal of Remote Sensing
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    • v.22 no.3
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    • pp.229-234
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    • 2006
  • In tactical theater, it is crucial to detect ground moving targets and to locate them precisely. This problem can be resolved by using SAR (Synthetic Aperture Radar) sensors providing GMTI (Ground Moving Target Indication) capability. In general, to implement a robust GMTI sensor is not simple because of the strong competitions between target signals and clutter signals from the ground, and low speed of moving targets. Contrary to the case that a delay canceller is mostly suitable for ground surveillance radars, DPCA (Displaced Phase Centered Antenna) or STAP (Space Time Adaptive Processing) techniques have been widely adapted for GMTI function of modern airborne radars. In this paper, a new scheme of DPCA using two passive antennas with vertical separation is proposed, which also provides good clutter cancellation performance. The proposed scheme realizes full azimuth coverage for DPCA operation on an airborne platform, which is impossible with classical DPCA configuration. Simulations using various conditions have been performed to validate the proposed scheme, and the results are acceptable.

Ground Moving Target's Velocity Estimation in SAR-GMTI (SAR-GMTI에서 지상이동표적의 속도 추정 기법)

  • Bae, Chang-Sik;Jeon, Hyeon-Mu;Yang, Dong-Hyeuk;Yang, Hoon-Gee
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.2
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    • pp.139-146
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    • 2017
  • A ground moving target's velocity estimation algorithm applicable for a SAR-GMTI system using 2 channel displaced phase center antenna(DPCA) is proposed. In this algorithm, we assume target's across-track velocity can be estimated by along-track interferometry (ATI) and present a method to estimate target's along-track velocity. To accomplish this method, we first transform a radar-target geometry in which a moving target has zero velocity via altering a radar velocity such that target's velocity is reflected into it and next manipulate the spectral centers of the subapertures within the synthetic aperture. The validity of the proposed algorithm is demonstrated through simulation results showing the performance of the target's velocity estimation and the enhancement of reconstructed target image quality in terms of resolution and SINR.