• Title/Summary/Keyword: Moving target

Search Result 830, Processing Time 0.038 seconds

Moving-Target Tracking Based on Particle Filter with TDOA/FDOA Measurements

  • Cho, Jeong-A;Na, Han-Byeul;Kim, Sun-Woo;Ahn, Chun-Soo
    • ETRI Journal
    • /
    • v.34 no.2
    • /
    • pp.260-263
    • /
    • 2012
  • In this letter, we propose a moving-target tracking algorithm based on a particle filter that uses the time difference of arrival (TDOA)/frequency difference of arrival (FDOA) measurements acquired by distributed sensors. It is shown that the performance of the proposed algorithm, based on the particle filter, outperforms the one based on the extended Kalman filter. The use of both the TDOA and FDOA measurements is shown to be effective in the moving-target tracking. It is proven that the particle filter deals with the nonlinear nature of the movingtarget tracking problem successfully.

Research on Synthesis of Radiation Noise from Moving Target (이동하는 표적의 방사소음 합성기법 연구)

  • 배재휘
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.3 no.1
    • /
    • pp.58-65
    • /
    • 2000
  • A target signal simulation method for passive sonar systems is introduced. The method uses multirate signal processing techniques to simulate moving target signals in the multi-path sound propagation environment by introducing Lloyd's mirror and Doppler effect. Time and frequency variation of target signal due to the target maneuvering is also considered to provide realistic ship signatures in the LOFAR gram so that the simulated target is used for sonar operator training. Synthesized target characteristics is analyzed and compared with real target signal in terms of interference pattern and frequency variation in the LOFAR gram.

  • PDF

A Study on Model for Target Assignment and Gun Ammunition Required for Naval Surface Warfar (수상전에서의 표적할당 및 포탄소요양 결정모형)

  • Min Gye-Ryo;Kim Heung-Man
    • Journal of the military operations research society of Korea
    • /
    • v.13 no.1
    • /
    • pp.28-44
    • /
    • 1987
  • This thesis presents a model to assign targets and to determine gun ammunitions required for naval surface warfare. Delivery errors of weapon systems and vulnerability of moving targets are analyzed, then probability to kill moving battle sihps is computed. A weapon-target allocation model is proposed by using the Out of Kilter technique. A model to determine ammunitions required for killing moving targets is also designed. The models are evaluated by simulation and sensitivity analysis.

  • PDF

VELOCITY ESTIMATION OF MOVING TARGETS BY AZIMUTH DIFFERENTIALS OF SAR IMAGES;PRELIMINARY RESULTS

  • Park, Jeong-Won;Jung, Hyung-Sup;Won, Joong-Sun
    • Proceedings of the KSRS Conference
    • /
    • 2007.10a
    • /
    • pp.625-628
    • /
    • 2007
  • We present an efficient and robust technique to estimate the velocity of moving targets from a single SAR image. In SAR images, azimuth image shift is a well known phenomenon, which is observed in moving targets having slant-range velocity. Most methods estimated the velocity of moving targets from the distance difference between the road and moving targets or between ship and the ship wake. However, the methods could not be always applied to moving targets because it is difficult to find the road and the ship wake. We adopted a method estimating the velocity of moving targets from azimuth differentials of range-compressed image. This method is based on an assumption that Doppler center frequency shift of moving target causes a phase difference in azimuth differential values. The phase difference is linearly distorted by Doppler rate due to the geometry of SAR image. The linear distortion is eliminated from phase removal procedure, and the constant phase difference is estimated. Finally, range velocity estimates for moving targets are retrieved. This technique is tested using an ENVISAT ASAR image in which several unknown ships are presented. The theoretical accuracy of this technique is discussed by SAR simulation. The advantages and disadvantages of this method over the conventional method are also discussed.

  • PDF

Velocity Estimation of Moving Targets by Azimuth Differentials of SAR Images (SAR 영상의 Azimuth 차분을 이용한 움직이는 물체의 속도측정방법)

  • Park, Jeong-Won;Jung, Hyung-Sup;Won, Joong-Sun
    • Korean Journal of Remote Sensing
    • /
    • v.24 no.2
    • /
    • pp.91-98
    • /
    • 2008
  • We present an efficient and robust technique to estimate the velocity of moving targets from a single SAR image. In SAR images, azimuth image shift is a well blown phenomenon, which is observed in moving targets having slant-range velocity. Most methods estimated the velocity of moving targets from the distance difference between the road and moving targets or between ship and the ship wake. However, the methods could not be always applied to moving targets because it is difficult to find the road and the ship wake. We propose a method for estimating the velocity of moving targets from azimuth differentials of range-compressed image. This method is based on a phenomenon that Doppler center frequency shift of moving target causes a phase difference in azimuth differential values. The phase difference is linearly distorted by Doppler rate due to the geometry of SAR image. The linear distortion is eliminated from phase removal procedure, and then the constant phase difference is estimated. Finally, range velocity estimates for moving targets are retrieved from the constant phase difference. This technique was tested using an ENVISAT ASAR image in which several unknown ships are presented. In the case of a isolated target, the result was nearly coincident with the result from conventional method. However, in the case of a target which is located near non-target material, the difference of the result between from our algorithm and from conventional method was more than 1m/s.

A Survey on Moving Target Indication Techniques for Small UAVs : Parametric Approach (소형 무인항공기용 이동표적 표시기법에 대한기술 동향 분석 : 매개변수방식)

  • Yun, Seung Gyu;Kang, Seung Eun;Ko, Sang Ho
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.42 no.7
    • /
    • pp.576-585
    • /
    • 2014
  • In this paper, we survey the Moving Target Indication(MTI) techniques for small UAVs. MTI consists of image alignment phase and frame differencing correction phase, and image alignment has two ways of parametric approach which is mainly focused in this paper and non-parametric approach. Since small UAVs are operated in the low altitude, the parallax is considerable and the epipolar geometry is applied to compensate the parallax. The related works and future works are presented.

Analysis of High Resolution Range Estimation for Moving Target Using Stepped Frequency Radar with Coherent Pulse Train (코히어런트 펄스열을 갖는 계단 주파수 레이더를 이용한 이동표적의 고해상도 거리 추정 분석)

  • Sim, Jae-Hun;Bae, Keun-Sung
    • Journal of IKEEE
    • /
    • v.22 no.3
    • /
    • pp.599-604
    • /
    • 2018
  • A Stepped Frequency Radar(SFR) is a method that realizes high resolution range estimation by increasing the frequency of transmission pulses at regular intervals to generate a wide synthetic bandwidth. However, in the case of a moving target, accurate range estimation becomes difficult due to the range-Doppler coupling. In this paper, the process of high resolution range estimation by compensation of the range-Doppler coupling with estimated velocity of the moving target using the SFR waveform with Coherent Pulse Train(CPT) is analyzed and it was verified through simulation.

Design of a Protected Server Network with Decoys for Network-based Moving Target Defense

  • Park, Tae-Keun;Park, Kyung-Min;Moon, Dae-Sung
    • Journal of the Korea Society of Computer and Information
    • /
    • v.23 no.9
    • /
    • pp.57-64
    • /
    • 2018
  • In recent years, a new approach to cyber security, called the moving target defense, has emerged as a potential solution to the challenge of static systems. In this paper, we design a protected server network with a large number of decoys to anonymize the protected servers that dynamically mutate their IP address and port numbers according to Hidden Tunnel Networking, which is a network-based moving target defense scheme. In the network, a protected server is one-to-one mapped to a decoy-bed that generates a number of decoys, and the decoys share the same IP address pool with the protected server. First, the protected server network supports mutating the IP address and port numbers of the protected server very frequently regardless of the number of decoys. Second, it provides independence of the decoy-bed configuration. Third, it allows the protected servers to freely change their IP address pool. Lastly, it can reduce the possibility that an attacker will reuse the discovered attributes of a protected server in previous scanning. We believe that applying Hidden Tunnel Networking to protected servers in the proposed network can significantly reduce the probability of the protected servers being identified and compromised by attackers through deploying a large number of decoys.

Target Velocity Estimation Technique Using CPA Analysis at the Moving Receiver (CPA분석을 이용한 기동하는 수신기에서의 표적 속도 추정기법)

  • Lee, Su-Hyoung;Kim, Jeong-Soo;Lee, Kyun-Kyung
    • The Journal of the Acoustical Society of Korea
    • /
    • v.28 no.4
    • /
    • pp.336-342
    • /
    • 2009
  • A conventional Closest Point of Approach (CPA) analysis allows a non-maneuvering moving source that is radiating a constant frequency tone to be located using doppler shifted frequency measurements obtained by a stationary receiver. The original frequency, relative speed of the target, time at the CPA, and range from the CPA to the sensor are estimated by the conventional CPA. However, this paper proposes a new CPA analysis that allows the motion parameters of a target to be estimated using the bearing and frequency measurements obtained by a moving receiver that has a constant velocity. The validity of the proposed estimation scheme is confirmed through a performance analysis and simulation study.

A Study on Robust Moving Target Detection for Background Environment (배경환경에 강인한 이동표적 탐지기법 연구)

  • Kang, Suk-Jong;Kim, Do-Jong;Bae, Hyeon-Deok
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.48 no.5
    • /
    • pp.55-63
    • /
    • 2011
  • This paper describes new moving target detection technique combining two algorithms to detect targets and reject clutters in video frame images for surveillance system: One obtains the region of moving target using phase correlation method using $N{\times}M$ sub-block images in frequency domain. The other uses adaptive threshold using learning weight for extracting target candidates in subtracted image. The block region with moving target can be obtained using the characteristics that the highest value of phase correlation depends on the movement of largest image in block. This technique can be used in camera motion environment calculating and compensating camera movement using FFT phase correlation between input video frame images. The experimental results show that the proposed algorithm accurately detects target(s) with a low false alarm rate in variety environment using the receiver operating characteristics (ROC) curve.