• Title, Summary, Keyword: Micro-Doppler

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Efficient Measurement System to Investigate Micro-Doppler Signature of Ballistic Missile

  • Choi, In-O;Kim, Kyung-Tae;Jung, Joo-Ho;Kim, Si-Ho;Park, Sang-Hong
    • International Journal of Aeronautical and Space Sciences
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    • v.17 no.4
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    • pp.614-621
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    • 2016
  • Micro-Doppler (MD) shift caused by the micro-motion of a ballistic missile (BM) can be very useful to identify it. In this paper, the MD signatures of three scale-model BMs are investigated using a portable measurement system. The measurement system consists of an X-band 2-by-2 phase comparison mono-pulse radar, and a mechanical device that can impart controlled spinning and coning motions simultaneously to a model to yield the MD signature that replicates the characteristic of each target and the corresponding micro-motion. The coning motion determined the overall period of MD, and the spinning motion increased its amplitude. MD was also dependent on aspect angle. The designed system is portable, and can implement many micro-motions; it will contribute to analysis of MD in various situations.

Analysis of Micro-Doppler Signatures from Rotating Propellers Using Modified HHT Method (수정된 HHT 기법을 이용하여 회전하는 프로펠러 날개에 의한 마이크로 도플러 신호의 해석)

  • Park, Ji-Hoon;Choi, Ik-Hwan;Myung, Noh-Hoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.9
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    • pp.1100-1106
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    • 2012
  • This paper has presented the analysis of the micro-Doppler signatures scattered from the blades of the rotating propeller using the modified HHT method, one of the joint time-frequency analysis methods. The field scattered from the blade edge of the propeller was calculated using equivalent current method(ECM). After the acquisition of the scattered field data in the time domain, the modified HHT method was applied to analyze the micro-Doppler signature. The analysis results showed not only a good agreement with the realistic dynamic characteristic of the blade but also sinusoidally varing characteristics of the micro-Doppler signatures generated from rotating objects. It could be concluded that the joint time-frequency analysis via the modified HHT provided the discriminative characteristics for recognizing a small aircraft target with small RCS value.

Efficient Translational Motion Compensation for Micro-Doppler Extraction of Ballistic Missiles

  • Jung, Joo-Ho;Kim, Si-Ho;Choi, In-O;Kim, Kyung-Tae;Park, Sang-Hong
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.1
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    • pp.129-137
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    • 2017
  • When the micro-Doppler (MD) image of a ballistic missile is derived, the translational motion compensation (TMC) method is usually applied to the inverse synthetic aperture radar (ISAR) image, but yields poor results because of the micro-motion of the ballistic missile. This paper proposes an efficient TMC method to obtain a focused MD image of a ballistic missile engaged in complicated micro-motion. During range alignment, range profiles (RPs) are coarsely aligned by using the 1D entropy cost function of RPs as a mark, then the coarsely-aligned RPs are fine-aligned by using the minimum 2D entropy of the MD image. During phase adjustment, the gradient of the phase error is appropriately weighted and added to the previous phase error to further fine-tune the aligned RPs. In simulations using the point scatterer model and the measured data from the real missile model, the proposed method provided better image focus than the existing method.

Multi-Target Position Estimation Technique Using Micro Doppler in FMCW Radar System (FMCW 레이다 시스템에서 마이크로 도플러를 이용한 다중 목표물 위치 추정 기법)

  • Yoo, Kyungwoo;Chun, Joohwan;Ryu, Chung-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.11
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    • pp.996-1003
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    • 2016
  • Trilateration technique using time of arrival(TOA) is generally used for single target position estimation in radar system. However, trilateration technique has limitation in case of multiple targets, since it is difficult to distinguish the measurements corresponding to the respective targets. In this study, to eliminate ambiguity of relation between measurements and targets, micromotion of each target is measured by micro Doppler which is actively studied in radar industry nowadays and these information are used to distinguish measurements used at trilateration technique. Resultingly, the trilateration technique is applied successfully for each target. The targets are considered as multiple submissiles separated from the missile. Simulation results shows the performance of the proposed algorithm.

Experimental Study of Drone Detection and Classification through FMCW ISAR and CW Micro-Doppler Analysis (고해상도 FMCW 레이더 영상 합성과 CW 신호 분석 실험을 통한 드론의 탐지 및 식별 연구)

  • Song, Kyoungmin;Moon, Minjung;Lee, Wookyung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.2
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    • pp.147-157
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    • 2018
  • There are increasing demands to provide early warning against intruding drones and cope with potential threats. Commercial anti-drone systems are mostly based on simple target detection by radar reflections. In real scenario, however, it becomes essential to obtain drone radar signatures so that hostile targets are recognized in advance. We present experimental test results that micro-Doppler radar signature delivers partial information on multi-rotor platforms and exhibits limited performance in drone recognition and classification. Afterward, we attempt to generate high resolution profile of flying drone targets. To this purpose, wide bands radar signals are employed to carry out inverse synthetic aperture radar(ISAR) imaging against moving drones. Following theoretical analysis, experimental field tests are carried out to acquire real target signals. Our preliminary tests demonstrate that high resolution ISAR imaging provides effective measures to detect and classify multiple drone targets in air.

Investigation of the Performance of Spectral Domain Optical Doppler Tomography with High-speed Line Scanning CMOS Camera and Its Application to the Blood Flow Measurement in a Micro-tube

  • Park, Cheol Woo;Lee, Changho;Lim, SooHee;Ni, Aleksey;An, Jin Hyo;Lee, Ho;Bae, Jae Sung;Kim, Jeehyun
    • Journal of the Optical Society of Korea
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    • v.16 no.2
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    • pp.174-180
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    • 2012
  • In this study, the feasibility of spectral domain optical Doppler tomography for measuring blood flow characteristics in a micro-tube was demonstrated through several experiments. The use of an SD-ODT system in blood flow measurement can provide high resolution images (5 microns resolution). We prepared three capillary tubes to reveal the effect of different concentrations of hematocrit ratio (HR). One tube serves as the control. The two other tubes contained different concentrations of HR (5%, 25%). Three different capillary tube inlet flow velocities were tested in the present study. The Reynolds number (Re) which is based on the capillary tube inner diameter ranges from Re=6 to 48. We calculated a Doppler shift of the power spectrum of the temporal interference fringes with Kasai autocorrelation function to achieve the velocity profile of the flow. As a result, SD-ODT systems could not detect the cell depletion layer in the present study due to the limitation of spatial resolution. Nevertheless, these systems were proven to be capable of observing the RBCs of blood.

Multifrequency Imaging of Radar Turntable by Phase and Amplitude Measurement (다주파수 신호를 사용한 회전물체의 위상과 진폭측정에 의한 영상)

  • Suh, Kyoung-Whoan;Lee, Kyoung-Soo;Kim, Se-Youn;Ra, Jung-Woong
    • Proceedings of the KIEE Conference
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    • pp.392-397
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    • 1987
  • This paper concerns a method for micro-wave imaging. The image reconstruction of a perfect conducting cylinder by phase and amplitude measurement using the X-Band multifrequency is presented troll the simulated data. The high degree of range resolution is achieved using large signal band-width and cross-range resolution is obtained by doppler processing. The comparison of image reconstruction between range doppler processing and circular convolution algorithm is also shown.

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A Study of Micro Displacement Measurement of Micro System using the Laser Interferometer (레이저 간섭계를 이용한 마이크로 시스템의 미소변위 측정에 관한 연구)

  • Choi, Kyung-Hyun;Kim, Chang-Jong;Cho, Su-Jeong
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.5 no.2
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    • pp.22-26
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    • 2006
  • This paper addresses the development of a laser interferometer to measure micro displacement for a micro system. The laser interferometer is able to measure micro displacement during a few micro seconds with non-contact. In order to employ the interferometer, the displacement calibration experiment should be required. For the experiment, a laser probe installed on the optical table with optical devices and a micro stage. The velocity decoding board is also added to calculate doppler shift frequency directly. The output signal is processed by LabView. Finally experiments are found out the relation between displacement and output signal.

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A Study on the Portable Micro Displacement Measurement Using Laser Interferometer (레이저 간섭계를 이용한 이동형 미세 변위 측정에 관한 연구)

  • Choi, K.H.;Yang, H.C.
    • Journal of the Korea Society For Power System Engineering
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    • v.10 no.2
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    • pp.99-103
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    • 2006
  • The laser interferometer has been used for measurement of the micro displacement error. Although the laser interferometer is widely accepted as a tool for measurement of motion accuracy, the set-up procedure is time-consuming because of the strict requirement on alignment between a laser head and optic units. This paper addresses the development of a laser interferometer to measure the micro displacement for a micro machine. The portable laser interferometer which integrates a laser probe and optics, is developed for the convenient measurement. For the experiment, moving mirror set up on the micro stage. The velocity decoding board is also added to calculate doppler shift frequency directly. The output signal is obtained and analyzed by LabView. Finally experiments are found out the relation between micro displacement and output signal.

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Human Walking Detection and Background Noise Classification by Deep Neural Networks for Doppler Radars (사람 걸음 탐지 및 배경잡음 분류 처리를 위한 도플러 레이다용 딥뉴럴네트워크)

  • Kwon, Jihoon;Ha, Seoung-Jae;Kwak, Nojun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.7
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    • pp.550-559
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    • 2018
  • The effectiveness of deep neural networks (DNNs) for detection and classification of micro-Doppler signals generated by human walking and background noise sources is investigated. Previous research included a complex process for extracting meaningful features that directly affect classifier performance, and this feature extraction is based on experiences and statistical analysis. However, because a DNN gradually reconstructs and generates features through a process of passing layers in a network, the preprocess for feature extraction is not required. Therefore, binary classifiers and multiclass classifiers were designed and analyzed in which multilayer perceptrons (MLPs) and DNNs were applied, and the effectiveness of DNNs for recognizing micro-Doppler signals was demonstrated. Experimental results showed that, in the case of MLPs, the classification accuracies of the binary classifier and the multiclass classifier were 90.3% and 86.1%, respectively, for the test dataset. In the case of DNNs, the classification accuracies of the binary classifier and the multiclass classifier were 97.3% and 96.1%, respectively, for the test dataset.