• Title/Summary/Keyword: Clutter

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A Study on the Performance of a Radar Clutter Suppression Algorithm Based on the Adaptive Clutter Prewhitening Filter and Droppler Filter Bank (Adaptive Clutter Prewhitening Filter와 Doppler Filter Bank를 이용한 레이다 Clutter 제거 알고리듬의 성능에 관한 연구)

  • Kim, Yong-Ho;Lee, Hwang-Soo;Un, Chong-Kwan;Lee, Won-Kil
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.6
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    • pp.140-146
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    • 1989
  • In many situations, radar targets are embedded in a clutter environment and clutter rejection is required. The clutter is unwanted radar echoes and may arise owing to reflections from ground and weather disturbances and statistical properties of the clutter vary with range and azimuth as well as time. That is, adaptive signal processing is required. In this paper, a clutter suppression algorithm based on the clutter whitening filter (WF) and doppler filter bank(DFB) is described which provides improved performance compared with conventional nonadaptive clutter suppression algorithm that is the cascaded moving target indicator (MTI) and (DFB). The clutter whitening filter algorithm is based on the Burg's maximum entropy method.

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Adaptive Gaussian Model Based Ground Clutter Mitigation Method for Wind Profiler

  • Lim, Sanghun;Allabakash, Shaik;Jang, Bong-Joo
    • Journal of Korea Multimedia Society
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    • v.22 no.12
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    • pp.1396-1403
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    • 2019
  • The radar wind profiler data contaminates with various non-atmospheric components that produce errors in moments and wind velocity estimations. This study implemented an adaptive Gaussian model to detect and remove the clutter from the radar return. This model includes DC filtering, ground clutter recognition, Gaussian fitting, and cost function to mitigate the clutter component. The adaptive model tested for the various types of clutter components and found that it is effective in clutter removal process. It is also applied for the both time series and spectrum datasets. The moments estimated using this method are compared with those derived using conventional DC-filtering clutter removal method. The comparisons show that the proposed method effectively removes the clutter and produce reliable moments.

Clutter Suppression Method for Altitude and Mainlobe Clutter In Moving Platform Radar (이동 플랫폼 레이더에서 고도 클러터와 주엽 클러터 억제 기법)

  • Jeon, Hyeonmu;Bae, Chang-sik;Yang, Hoon-gee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.22 no.10
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    • pp.1386-1391
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    • 2018
  • The radar in the moving platform is interfered by the mainlobe clutter as well as the altitude clutter that is received from sidelobe. The altitude clutter is relatively short range compared to mainlobe clutter and therefore enters the radar with a strong signal. As these clutters are major reason making the probability of false alarm high, it is required to suppress both altitude clutter and mainlobe clutter. In this paper, It is proposed the clutter suppression method consisted of two pulse canceller to suppress the clutters being two frequency area in moving platform. It is analyzed the correlation of output signals according to the use of pulse canceller and provided the structure of staggered pulse canceller considered the correlation. Finally, it shows that altitude clutter and mainlobe clutter are suppressed by proposed staggered pulse canceller using the simulation.

Estimation of Ground Clutter Reflectivity based on the CFT(Captive Flight Test) (항공기 탑재 시험을 통한 지상 클러터 반사계수 추정)

  • Son, Chang-Hee
    • Journal of the Korea Institute of Military Science and Technology
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    • v.9 no.2 s.25
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    • pp.87-95
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    • 2006
  • The performance of a microwave missile seeker and radar operating in an air-to-air look-down mode is strongly influenced by the presence of ground clutter In order to correctly account for the effects of ground clutter, it is required to develop a model capable of representing clutter characteristics as a function of range and/or frequency. In this paper, a program to estimate the clutter reflectivity for various ground conditions is developed, using the actually measured data and the data available from open literatures. In addition, clutter characteristics measured for various ground conditions such as sea, agricultural area, urban city and industrial area through the captive flight tests are presented.

Hough Transform Clutter Reduction Algorithm for Piecewise Linear Path Active Sonar Target Detection and Tracking Improvement (구간선형기동 능동소나표적 탐지 추적 성능향상을 위한 허프변환 클러터제거 알고리즘)

  • Kim, Seong-Weon
    • The Journal of the Acoustical Society of Korea
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    • v.32 no.4
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    • pp.354-360
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    • 2013
  • In this paper, it is discussed that the detection and tracking performance of the piecewise linear path underwater target is improved using clutter reduction algorithm in heavy clutter density environment. Through clutter reduction algorithm using Hough Transform, measurements which represent clutter features are removed and the performance of target tracking on the remaining measurements is demonstrated applying CMKF-L(Converted Measurement Kalman Filter with Linearization) as tracking filter. Algorithm performance test is conducted using simulation data and real sea-trial data and by applying the proposed algorithm in heavy clutter density environment, it is confirmed that the target is tracked consistently and stably with clutter rejected measurements.

UWB Automobile Short Range Radar Receivers Performance In a Log-Normal Clutter Background (Log-Normal Clutter 환경에서 차량용 UWB 단거리 레이더 수신기의 성능분석)

  • Kumaravelu, Nandeeshkumar;Ko, Seok-Jun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.48 no.9
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    • pp.59-64
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    • 2011
  • Ultra wideband radars attract considerable attention as a short range automotive radar because of its high range resolution. Radar signal reflected from a target often contains unwanted echoes called as clutter, so the detection of target is difficult due to clutter echoes. Therefore, it is important to investigate the radar detector for better detecting from the reflected signals. In this paper, the optimal detector is obtained for various mean and variance value in log-normal clutter environment. The types of non-coherent detectors used are square law detector, linear detector, and logarithmic detector. The performances of detectors are compared in log normal clutter environment and the suitable detector is determined for automotive short range radar application.

Measurement and Analysis of Clutter Loss in Urban/Suburban below 24 GHz (24 GHz 이하 도심/부도심의 클러터 손실 측정 및 분석)

  • Kang, Young-Heung;Lee, Haeng-Seon;Park, Sung-Won;Lee, Il-Yong;Lim, Jong-Hyuk;Yoon, Dea-Hwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.6
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    • pp.441-448
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    • 2018
  • Recently, measurements on clutter loss due to buildings in urban/suburban areas at 3, 6, 10, 18, and 24 GHz have been performed by the Radio Research Agency with the purpose of predicting the clutter loss close to actual urban/suburban propagation for 5G mobile communication. In this work, we have compared the urban clutter loss to suburban clutter loss for a transmit antenna height of 85 m. Furthermore, we have estimated the error between the predicted loss as per ITU-R P.2108 and the measured clutter loss. Our results indicate that for higher frequencies, the measured clutter loss in urban/suburban areas is higher and so lower than the predicted clutter loss. In conclusion, it is necessary to improve the prediction model for clutter loss by taking into account the measured clutter loss in urban/suburban areas in the prediction model.

IRF Analysis Considering Clutter Background for SAR Image Qualification

  • Jung, Chul-H.;Oh, Tae-B.;Song, Sun-H.;Kwag, Young-K.
    • International Journal of Aeronautical and Space Sciences
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    • v.10 no.1
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    • pp.83-90
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    • 2009
  • A new IRF (Impulse Response Function) analysis technique in high resolution SAR image is presented by taking into account the real clutter environment. In order to investigate the realistic effect of clutter background on the impulse response function of SAR image, an ideally generated impulse response function is superimposed with a large number of background clutter data which are extracted from the various regions of an actual SAR image. As a performance measure, PSLR (Peak Sidelobe Ratio) of the clutter-contained IRF is presented in the various groups of clutter background, and finally the results are compared with the stochastic model.

The Estimation of the Surface Sidelobe Clutter Distribution for the HPRF Waveform of the M/W Seeker (마이크로파 탐색기의 HPRF 파형에 대한 지표면 부엽 클러터 분포의 추정)

  • Kim, Tae-Hyung;Byun, Young-Jin;Yi, Jae-Woong
    • Journal of the Korea Institute of Military Science and Technology
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    • v.12 no.1
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    • pp.1-7
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    • 2009
  • Tracking and detecting targets by the M/W seeker is affected by the clutter reflecting from the earth's surface. In order to detect the look-down retreating targets, which appear in the sidelobe clutter region, in the M/W seeker of High PRF mode, it is necessary to understand statistical characteristics of the surface sidelobe clutter. Statistical analysis of sidelobe clutter is conducted for several configurations of the surface using data obtained by the CFT (Captive Flight Test) of the M/W seeker in High PRF mode. The probability density function(PDF) fitting is conducted for several configuration and conditions of the surface. PDFs and PDF parameters, which best describe statistical distribution of sidelobe clutter, are estimated.

Time-Domain Model of Surface Clutter for Airborne Phase-Array Radar (항공기 위상 배열 레이더에서 시간 영역의 지상클러터 생성 모델)

  • Kim, Tae-Hyung;Kim, Eun-Hee;Kim, Seon-Joo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.7
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    • pp.730-736
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    • 2013
  • Time-domain clutter generation model for airborne pulse doppler phase-array radar is presented. Time-domain surface clutter signal is generated assuming earth of a sphere and considering geometry of a clutter patch, and generation of sub-array clutter signal is presented. The generated sub-array clutter signal can be used by simulation input signal in various radar applications of DBF(Digital Beamforming), ABF(Adaptive Beamforming), Stap(Space-Time Adaptive Processing) and etc.