• 제목/요약/키워드: agency for defense development

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CDGPS의 요동 측정 결과를 이용한 Spotlight SAR 영상 형성에 관한 연구 (A Study on Spotlight SAR Image Formation by using Motion Measurement Results of CDGPS)

  • 황정훈;고영창;김소연;권경일;윤상호;김형석;신현익
    • 한국군사과학기술학회지
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    • 제21권2호
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    • pp.166-172
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    • 2018
  • To develop and evaluate the real-time SAR(Synthetic Aperture Radar) motion measurement system, true antenna phase center(APC) positions during SAT(Synthetic Aperture Time) are needed. In this paper, CDGPS(Carrier phase Differential Global Positioning System) post processing method is proposed to get the true APC position for spotlight SAR image formation. The CDGPS position is smoothed to remove high frequency noise which exists inherently in the carrier phase measurement. This paper shows smoothed CDGPS data is enough to provide the true APC for high-quality SAR image formation through motion measurement result, phase error estimation and IRF(Impulse Response Function) analysis.

거리측정용 고반복 Nd:YAG 레이저 발진부 설계 (Design of High Repetition Nd:YAG Laser Transmitter Module for Rangefinder)

  • 박용찬;최영수;김현규;권우근;강응철
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 A
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    • pp.460-463
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    • 1993
  • In this paper, The laser transmitter module is designed as the subsystem of the high repetitive laser rangefinder. The module consists of high voltage power supply, high voltage control circuits, high voltage discharger, electro-optic Q-switch driver, and laser resonator. The high voltage power supply is composed of 2-phase flyback converter. And it has 220W power level and 78% conversion efficiency. From the Q-switch driver of the crossed porro resonator, the phase retardation voltage is switched from 600V to -1500V with 200ns falling time. The module can be operated up to 15Hz. And it generates the laser pulse which has 20ns width and 80mJ.

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X-대역 LFM 신호생성을 위한 진행파형 전광변조기의 설계 및 제작 (Design and Manufacture of Traveling-wave Electro-optic Modulator for X-band LFM Signal Generation)

  • 이민우;류성준;배영석;장성훈;유준형;신진우
    • 한국군사과학기술학회지
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    • 제24권6호
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    • pp.610-618
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    • 2021
  • In this paper, a photonic-based microwave system technology is described, and a traveling-wave electro-optic modulator is designed and manufactured as a key component. The fabricated modulator is composed of a metal diffusion waveguide for optical transmission and a planar waveguide electrode on lithium niobate substrate for microwave transmission. The electro-optic response bandwidth of I and Q channels in a fabricated dual parallel Mach-Zehnder modulator were measured for 27.67 and 28.11 GHz, respectively. Photonic four times up-converted X-band frequency and linear frequency modulated signal were confirmed using the fabricated electro-optic modulator by S-band input signal. The confirmed broadband signal can be applied to a microwave system for surveillance and high-resolution ISAR imaging.

활공탄의 안전분리 해석을 위한 지상투하시험 (Ground Ejection Tests for the Safe Separation Analysis of a Gliding Bomb)

  • 이기두;이인원;박영근;백승욱;정나현;정상준
    • 한국항공우주학회지
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    • 제41권6호
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    • pp.502-508
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    • 2013
  • 새로이 개발된 유도키트를 장착한 모의 활공탄에 대하여 지상투하시험을 수행하였다. 사출형 분리장치의 카트리지와 오리피스 조합에 따른 사출력을 측정한 결과, 오리피스 직경이 클수록 사출력이 크게 작용하였으며, 투하된 후 날개 전개장치를 비롯하여 탄의 내부에 탑재된 시험 장치들의 정상 작동을 확인하였다. 또한 영상자료로부터 활공탄의 피치각은 전방과 후방의 사출력 분포 즉 카트리지와 오리피스 조합에 따라 증가 또는 감소하는 것으로 분석되었다.

선체진동신호를 이용한 3차원 수중방사소음 패턴 산출에 대한 수치해석 연구 (A Numerical Analysis Study on the Estimation of the 3D Underwater Radiated Noise Pattern using the Hull Vibration Signals)

  • 이종주;강명환;한승진;배수룡;김재호;정우진
    • 한국소음진동공학회논문집
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    • 제24권10호
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    • pp.770-779
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    • 2014
  • In this study, a numerical estimation method for 3D underwater radiated noise pattern using hull vibration and total acoustic power of the vibrating structure in the far-field is proposed. The underwater radiated noise pattern is known to be predicted using the vibration signals and radiation efficiency of each surface patch. But it is very difficult to know radiation efficiency of each surface patch which is one of important factors to calculate the 3D underwater radiated noise pattern. Instead of using radiation efficiency of each patch, the underwater radiated noise level is modified with the total acoustic power of the vibrating structure. The suggested estimation method for underwater radiated noise pattern is discussed with numerical model.

적외선 센서를 이용한 열상장비의 구현 (Thermal Imager Implementation Using Infrared Sensor)

  • 유위경;윤은숙;김창우;송인섭;홍석민
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1992년도 하계학술대회 논문집 B
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    • pp.1250-1254
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    • 1992
  • This paper describes the designed and fabricated thermal imaging system with the SPRITE(Signal PRocessing in The Element) detector, operating in the 3-12 micron band. This system consists of an afocal telescope, a scan unit containing the SPRITE detector, an electronic processor unit and a cooler. The optical scan system utilizing rotating polygon and oscillating mirror, is 2-dimensional serial/parallel scan type using five elements of the detector. And the electronic processor unit performs digital scan conversion to reform the parallel data stream into serial analog data compatable with conventional RS-170 video. The scan field of view is 40 ${\times}$ 26.7 and the MRTD(Minium Resolvable Temperature Difference) is 0.6 K at 7.5 cycles/mm. The acquired thermal image indicates that this system has a satisfactory performance.

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전자력 가속기 성능해석에 관한 연구 (A Study on The Performance Analysis of Electromagnetic Launcher)

  • 이주;김진성;안충호;문갑태;문상규
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1992년도 하계학술대회 논문집 B
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    • pp.703-705
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    • 1992
  • In this paper, we calculate the inductance and resistance of the electromagnetic launcher by means of the 3D FEM and the analytical method. And, the dynamic models of the electromagnetic launcher are presented to calculate it's performance. We compared the analysis results with the experimental results and conclude that the presented analysis methods are reasonable.

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비행표적에 대한 대공포 위협도 분석 연구 (A Study on the Anti-Air-Artillery Threat Envelop Analysis)

  • 양창덕;홍영석;양지연;김천영;류태규
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 2011년도 한국컴퓨터종합학술대회논문집 Vol.38 No.1(A)
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    • pp.9-12
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    • 2011
  • 본 논문에서는 지대공 교전모의를 위한 대공포 모델을 설계하였다. 교전모의를 위한 대공포 모델은 조준점을 획득하기 위해 비행표적의 현재 상태에 대해서 표적 비행경로를 예측해야 한다. 비행표적으로 발포하는 포탄의 조준 정보을 계산하기 위해 비행표적에 대한 조준점 예측 기법을 소개하였다. 비행표적의 살상확률을 Calton Function을 이용하여 계산하였다. 표적의 속도, 위치 변화에 따른 대공 살상영역을 분석하였다. 본 연구에서 설계한 대공포의 분석결과를 MSA 프로그램의 결과와 비교하였다.