• Title/Summary/Keyword: 지면 클러터

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Surface Clutter RCS Analysis for Ground-Based Radar (지면 기반 레이다에 대한 지표면 클러터 RCS 분석)

  • Moon, Chang-Man;An, Do-Jin;Lee, Joon-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.6
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    • pp.433-440
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    • 2018
  • A radar receives reflected signals from various objects to detect a target. Undesired object, called clutter, as well as the target generates reflected signals. The clutter radar cross section(RCS) is dependent on many factors, which are the antenna pattern, distance between the radar and the target, and the height of the target and the radar. Herein, surface clutter RCS for ground-based radar is analyzed, and the effect of the surface clutter RCS on the received signal is investigated.

Ground Clutter Modelling and Its Effect of Detection Performance in FOD FMCW Radar (FOD 탐지 FMCW 레이다에서 지면 클러터 모델링 및 탐지성능에 대한 영향 분석)

  • Song, Seungeon;Kim, Bong-seok;Kim, Sangdong;Kim, Minsoo;Kim, Yoonseob;Lee, Jonghun
    • Journal of the Korea Society for Simulation
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    • v.27 no.4
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    • pp.61-68
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    • 2018
  • This paper deals with ground clutter model for FOD (foreign object debris) surveillance FMCW (frequency modulated continuous waveform) radar. In the FOD surveillance radar, it has received not only the signals reflected by FOD, but also the clutters of the surface of the runway and the grassland simultaneously. However, to detect the FOD, the clutter rejection algorithm is necessary because the RCS (radar cross section) of FOD is nearly same to RCS of the grassland. In addition, it is difficult to apply the MTI (moving target indicator) algorithm as the clutter rejection algorithm because both the FOD and the clutter coexist stationarily. Hence, to remove the stationary clutter, it is crucial to accurately generate clutter map considering the surface of road. In this paper, in order to generate the clutter map, the respective beat signal at every range bin is generated in the case of only the surface without FOD, and then the beat signal accumulated 100 times. And also, Weibull distribution is applied to the RCS value to take the scattering distribution of clutter into consideration. The simulation results show that FOD can be well detected by applying the generated clutter map to the FOD FMCW radar.

Design and Fabrication of a W-band FMCW Radar for the Metal Target Detection Under the Ground Clutter Environment (지면 클러터 환경에서 금속표적감지를 위한 W-대역 FMCW 레이더의 설계 및 제작)

  • Park Jung-Dong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.7 no.3 s.18
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    • pp.93-100
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    • 2004
  • In this paper, we describe the design, fabrication, and test results of a W-band FMCW radar for the metal target detection under the ground clutter environment. In order to detect metal targets on the ground, we used a single cassegrain antenna with the beamwidth of $1.45^{\circ}$ which forms pencil-beam footprint on the ground. A log envelope detector was applied to improve radar performance in the severe ground clutter known as Weibull and log normal clutter. The designed FMCW radar can acquire altitude information from the ground clutter with $\sigma_0=-23dB$ at the height of 160m. The fabricated W-band FMCW radar transmits 11 dBm power and the dynamic range of the receiver is from -106dBm to -30dBm. The performances of the fabricated sensors were tested out in the fields and detected a car target of 200m apart on the grass.

Development of Real-Time Generation Methods of Simulated Surface Clutter Signals for Airborne Radar (항공기 레이다를 위한 모의 지상 클러터 신호의 실시간 생성 방법 개발)

  • Kim, Tae-Hyung;Moon, Hyun-Wook;Lee, Sung-Won;Ryu, Seong-Hyun;Yang, Eunjung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.2
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    • pp.176-187
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    • 2016
  • It takes considerable time to generate accurate clutter signal using conventional clutter generation scheme. In this paper, real-time schemes are proposed, which have reasonable accuracy and are applicable to testing the radar performance. Proposed methods are compared through the simulation, which represented that clutter signal can be generated in real-time when using proposed methods for simulated signal generator.

Method for Robust Ground Ranging Using Monopulse Radar in Heterogeneous Clutter Environment (모노펄스 레이다를 이용한 비균질 클러터 환경에서의 강건한 지면거리측정 방법)

  • Son, Jegyung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.6
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    • pp.602-609
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    • 2021
  • Aircraft radar has special function which is ranging from aircraft to ground of antenna boresight. Because ranging information is used to calibrate altitude of aircraft or to drop a conventional bomb, the measuring have to be precise and robust. Therefore, we propose a simple and efficient method using monopulse radar for ground ranging. Proposed method calculates balancing weight according to linearity of monopulse ratio and mixes two ranging measurements in proportional to the weight. By exploiting balancing weight, radar is able to react to various environment as monopulse ratio contains characteristics of clutter environment. As a result, robust ranging information can be achieved. We use DEM(Digital Elevation Model) in order to simulate heterogeneous environment. In experimental result, it is shown that proposed method shows better accuracy and precision in any environment.

Approaching Target above Ground Tracking Technique Based on Noise Covariance Estimation Method-Kalman Filter (잡음 공분산 추정 방식을 적용한 칼만필터 기반 지면밀착 접근표적 추적기법)

  • Park, Young-Sik
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.10
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    • pp.810-818
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    • 2017
  • This paper presents the approaching target above ground tracking based on Kalman filter applied to the proximity sensor for the active defense system. The proximity sensor located on the front of the countermeasure is not easy to detect when the anti-tank threat enters a fragment dispersion range due to limited antenna beamwidth. In addition, it is difficult for the proximity sensor to detect the anti-tank threat accurately at a terrestrial environment including various clutters. To solve these problems, this study presents the approaching target above ground tracking based on Kalman filter and applies the novel estimation method for a noise covariance matrix to improve a tracking performance. Then, a high tracking performance of Kalman filter applied the proposed noise covariance matrix is presented through field firing test results and the validity of the proposed study is examined.

다중표적용 추적 기술

  • 임상석
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.1
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    • pp.43-56
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    • 1997
  • 다중 표적 추적(MTT:Multiple Target Tracking)은 한 개 또는 그 이상의 센서들을 사용하는 감시(sureillance) 시스템을 위해서 컴퓨터와 마찬가지로 주변상황을 해석하는데 없어서는 안되는 중 요한 요소이다. 레이다, IR(Infrared) 및 Sonar등과 같은 전형적인 센서 시스템들은 여러 가지 신호원 (sources): 문제의 표적, 레이다 지면 클러터(clutter)같은 후면잡음 또는 열잡음같은 내부 오차 요인 으로부터 측정치(measurement)를 만들어 준다. 다중표적용 추적방식의 목적은 센서가 제공하는 측 정 데이터들을 동일한 신호원으로부터 나온 여러 세트의 관측치(observations) 또는 트랙(track)으로 구분해내는 것이다. 이와 같이 일단 트랙이 구성되고 확정되면 후면잡음이나 허위표적을 제거할 수 있 도록 표적의 수를 추산하고 표적의 속도나 예상위치 및 표적의 종류와 기타특성을 계산해낼 수 있다.

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SAR(Synthetic Aperture Radar) 3-Dimensional Scatterers Point Cloud Target Model and Experiments on Bridge Area (영상레이더(SAR)용 3차원 산란점 점구름 표적모델의 교량 지역에 대한 적용)

  • Jong Hoo Park;Sang Chul Park
    • Journal of the Korea Society for Simulation
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    • v.32 no.3
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    • pp.1-8
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    • 2023
  • Modeling of artificial targets in Synthetic Aperture radar (SAR) mainly simulates radar signals reflected from the faces and edges of the 3D Computer Aided Design (CAD) model with a ray-tracing method, and modeling of the clutter on the Earth's surface uses a method of distinguishing types with similar distribution characteristics through statistical analysis of the SAR image itself. In this paper, man-made targets on the surface and background clutter on the terrain are integrated and made into a three-dimensional (3D) point cloud scatterer model, and SAR image were created through computational signal processing. The results of the SAR Stripmap image generation of the actual automobile based SAR radar system and the results analyzed using EM modeling or statistical distribution models are compared with this 3D point cloud scatterer model. The modeling target is selected as an bridge because it has the characteristic of having both water surface and ground terrain around the bridge and is also a target of great interest in both military and civilian use.

Monopulse Secondary Surveillance Radar Antenna with Sum/Difference/SLS Channels (합/차/부엽 억제 채널을 갖는 모노펄스 보조 감시 레이더(용) 안테나)

  • Choi, Jong-Hwan;Chae, Hee-Duck;Park, Jong-Kuk;Na, Hyung-Gi
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.7
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    • pp.720-728
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    • 2011
  • In this paper, development of the monopulse secondary surveillance radar antenna which can be used for IFF system is presented. This antenna that is passive linear array is comprised of the row-feeder and several array-elements. The row-feeder provides sum, different and SLS(Sidelobe Supression) channels which are optimized the distribution of the power and phase ratio. The azimuthe sidelobe level of the sum channel beam pattern is -20 dBc or less. The SLS channel covers the sidelobe of the sum-chanel in the whole azimuth angle range. And the difference channel is used to perform the mono-pulse function, improves the detection accuracy in the azimuth direction. Meanwhile, the arrayelement makes shaped beam in the elevation angle, in order to eliminate the clutter and multipath effects from the ground. Performance of the antenna developed is verified by the measurement of S-parameters and far-field beam pattern, and satisfies all of the development specifications well.