scholarly journals Simulation of Moving Target Indication Radar System Based on VisSim/Comm Application

2021 ◽  
Vol 5 (2) ◽  
pp. 38-45
Author(s):  
Ghassan A. QasMarrogy ◽  
Husham J. Ahmad
Keyword(s):  
Mechanical Properties ◽  
Delay Line ◽  
Radar System ◽  
Moving Target ◽  
Moving Targets ◽  
Simulation Design ◽  
Stationary Target ◽  
Know How ◽  
Radar Signals

Moving target indication (MTI) is mainly designed to detect moving targets and while unmoving targets are filtered out. It focuses on the technique of the modern stationary target indication (STI), by using directly the signal details to determine the reflecting object’s mechanical properties, after that it becomes easier to find moving or non-moving targets. This paper presents the simulation design of the MTI radar system. The main purpose of this design is to help students in understanding the radar system subject and help teachers to explain this subject in a simpler approach. Both students and teachers need to know how the signals inside the MTI radar processor are working and how they are generated and related to each other. This paper introduces a method of simulation of MTI radar signals including, A-scope radar display, transmitted and returned radar pulses with constant and multiple PRF, n-delay line cancellers.

Ocular Tracking of Moving Targets: Effects of Perturbing the Background

2004 ◽  
Vol 91 (6) ◽  
pp. 2474-2483 ◽  
Author(s):  
Yasushi Kodaka ◽  
Kenichiro Miura ◽  
Kazuyo Suehiro ◽  
Aya Takemura ◽  
Kenji Kawano
Keyword(s):  
Opposite Direction ◽  
Direction Selectivity ◽  
Moving Target ◽  
Moving Targets ◽  
Progressive Reduction ◽  
Stationary Target ◽  
Ocular Tracking ◽  
Per Se ◽  
Background Motion ◽  
Stationary Background

Primates are able to track a moving target with their eyes, even when the target is seen against a stationary textured background. In this situation, the tracking eye movement induces motion of the background images on the retina (reafference) that competes with the motion of the target's retinal image, potentially disrupting the tracking of the target. Previous work on humans reported that brief perturbations of the background in the opposite direction to pursuit were much less disruptive than perturbations in the same direction as pursuit. Furthermore, if the background moved together with the pursuit target—so as to effectively eliminate the reafference—then the effects of a subsequent background perturbation showed less dependence on direction. This suggested that the direction selectivity to background perturbations during pursuit against a stationary background was due, at least in part, to the prior motion of the background secondary to the pursuit. We now report similar findings in monkeys, and in addition, have investigated the effect of moving the background while the animal was fixating a stationary target. In this situation, the ocular tracking responses to subsequent brief perturbations of the moving background were weaker when the perturbations were in the same direction as the prior background motion than when in the opposite direction. This suggests that the selective insensitivity to the reafferent visual input associated with pursuit across a stationary background is, at least in part, independent of pursuit per se and attributable to a progressive reduction in the sensitivity to sustained background motion.

scholarly journals A Low-Complexity FMCW Surveillance Radar Algorithm Using Two Random Beat Signals

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 608 ◽  
Author(s):  
Bong-seok Kim ◽  
Youngseok Jin ◽  
Sangdong Kim ◽  
Jonghun Lee
Keyword(s):  
Fourier Transform ◽  
Continuous Wave ◽  
Low Complexity ◽  
Radar System ◽  
Moving Target ◽  
Moving Targets ◽  
One Dimensional ◽  
Fmcw Radar ◽  
Target Indicator ◽  
Simulation Results

This paper proposes a low-complexity frequency-modulated continuous wave (FMCW) surveillance radar algorithm using random dual chirps in order to overcome the blind-speed problem and reduce the computational complexity. In surveillance radar algorithm, the most widely used moving target indicator (MTI) algorithm is proposed to effectively remove clutter. However, the MTI algorithm has a so-called ‘blind-speed problem’ that cannot detect a target of a specific velocity. In this paper, we try to solve the blind-speed problem of MTI algorithm by randomly selecting two beat signals selected for MTI for each frame. To further reduce the redundant complexity, the proposed algorithm first performs one-dimensional fast Fourier transform (FFT) for range detection and performs multidimensional FFT only when it is determined that a target exists at each frame. The simulation results show that despite low complexity, the proposed algorithm detects moving targets well by avoiding the problem of blind speed. Furthermore, the effectiveness of the proposed algorithm was verified by performing an experiment using the FMCW radar system in a real environment.

scholarly journals Azimuth Multichannel Reconstruction for Moving Targets in Geosynchronous Spaceborne–Airborne Bistatic SAR

2020 ◽  
Vol 12 (11) ◽  
pp. 1703
Author(s):  
Wei Xu ◽  
Zhengbin Wei ◽  
Pingping Huang ◽  
Weixian Tan ◽  
Bo Liu ◽  
...  
Keyword(s):  
Velocity Estimation ◽  
Target Velocity ◽  
Moving Target ◽  
Reconstruction Method ◽  
Moving Targets ◽  
Raw Data ◽  
Stationary Target ◽  
Slant Range ◽  
Geometry Model ◽  
Imaging Results

In a multichannel geosynchronous spaceborne–airborne bistatic synthetic aperture radar (GEO-SA-BiSAR) system, the airborne receiver can obtain high-resolution microwave images with good signal-to-noise ratios (SNRs) by passively receiving echoes from the desired area. Since the Doppler modulation and range history of a moving target are obviously different from a stationary target, a signal geometry model for moving targets in multichannel GEO-SA-BiSAR is established in this paper. According to simulation results, the along track velocity introduces target defocusing in azimuth, and the slant range velocity mainly causes multiple false targets. To resolve these problems, a modified multichannel reconstruction method in azimuth channel GEO-SA-BiSAR is proposed according to the azimuth multichannel impulse response of the imaged moving target. Before azimuth multichannel raw data combination, both spatial-variant range cell migration correction (RCMC) and azimuth nonlinear chirp scaling (ANLCS) should be performed to reduce the influence of the range offset and lower the Doppler bandwidth of the whole raw data, respectively. Afterward, a novel azimuth multichannel reconstruction algorithm is carried out via the modified reconstruction matrix based on the estimated target velocity. The target slant range velocity estimation is implemented by introducing the signal intensity ratio (SIR). Compared with the conventional method for the stationary target to handle the raw data of the moving target, the false targets could be obviously suppressed by using the proposed approach. Imaging results on both simulated point and distributed scene targets validate the proposed multichannel reconstruction approach.

scholarly journals High-Accuracy Recognition and Localization of Moving Targets in an Indoor Environment Using Binocular Stereo Vision

2021 ◽  
Vol 10 (4) ◽  
pp. 234
Author(s):  
Jing Ding ◽  
Zhigang Yan ◽  
Xuchen We
Keyword(s):  
Stereo Vision ◽  
Stereo Matching ◽  
Three Dimensional ◽  
Target Localization ◽  
Parallel Structure ◽  
Moving Target ◽  
Target Area ◽  
Moving Targets ◽  
Binocular Stereo Vision ◽  
Binocular Stereo

To obtain effective indoor moving target localization, a reliable and stable moving target localization method based on binocular stereo vision is proposed in this paper. A moving target recognition extraction algorithm, which integrates displacement pyramid Horn–Schunck (HS) optical flow, Delaunay triangulation and Otsu threshold segmentation, is presented to separate a moving target from a complex background, called the Otsu Delaunay HS (O-DHS) method. Additionally, a stereo matching algorithm based on deep matching and stereo vision is presented to obtain dense stereo matching points pairs, called stereo deep matching (S-DM). The stereo matching point pairs of the moving target were extracted with the moving target area and stereo deep matching point pairs, then the three dimensional coordinates of the points in the moving target area were reconstructed according to the principle of binocular vision’s parallel structure. Finally, the moving target was located by the centroid method. The experimental results showed that this method can better resist image noise and repeated texture, can effectively detect and separate moving targets, and can match stereo image points in repeated textured areas more accurately and stability. This method can effectively improve the effectiveness, accuracy and robustness of three-dimensional moving target coordinates.

Adjustable impact-time-control guidance law against non-maneuvering target under limited field of view

2021 ◽  
pp. 095441002110129
Author(s):  
Jun-Yong Lee ◽  
Hyeong-Guen Kim ◽  
H Jin Kim
Keyword(s):  
Field Of View ◽  
Control Technique ◽  
Moving Target ◽  
Time Error ◽  
Stationary Target ◽  
Impact Time ◽  
Maneuvering Target ◽  
Time Control ◽  
Guidance Law ◽  
Intercept Point

This article proposes an impact-time-control guidance law that can keep a non-maneuvering moving target in the seeker’s field of view (FOV). For a moving target, the missile calculates a predicted intercept point (PIP), designates the PIP as a new virtual stationary target, and flies to the PIP at the desired impact time. The main contribution of the article is that the guidance law is designed to always lock onto the moving target by adjusting the guidance gain. The guidance law for the purpose is based on the backstepping control technique and designed to regulate the defined impact time error. In this procedure, the desired look angle, which is a virtual control, is designed not to violate the FOV limit, and the actual look angle of the missile is kept within the FOV by tracking the desired look angle. To validate the performance of the guidance law, numerical simulation is conducted with different impact times. The result shows that the proposed guidance law intercepts the moving target at the desired impact time maintaining the target lock-on condition.

scholarly journals Extended GLRT Detection of Moving Targets for Multichannel SAR Based on Generalized Steering Vector

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1478
Author(s):  
Chong Song ◽  
Bingnan Wang ◽  
Maosheng Xiang ◽  
Wei Li
Keyword(s):  
Likelihood Ratio ◽  
Likelihood Ratio Test ◽  
Moving Target ◽  
Ratio Test ◽  
Constant False Alarm Rate ◽  
Moving Targets ◽  
Sar Images ◽  
Steering Vector ◽  
Current Cell ◽  
Data Vector

A generalized likelihood ratio test (GLRT) with the constant false alarm rate (CFAR) property was recently developed for adaptive detection of moving targets in focusing synthetic aperture radar (SAR) images. However, in the multichannel SAR-ground moving-target indication (SAR-GMTI) system, image defocus is inevitable, which will remarkably degrade the performance of the GLRT detector, especially for the lower radar cross-section (RCS) and slower radial velocity moving targets. To address this issue, based on the generalized steering vector (GSV), an extended GLRT detector is proposed and its performance is evaluated by the optimum likelihood ratio test (LRT) in the Neyman-Pearson (NP) criterion. The joint data vector formulated by the current cell and its adjacent cells is used to obtain the GSV, and then the extended GLRT is derived, which coherently integrates signal and accomplishes moving-target detection and parameter estimation. Theoretical analysis and simulated SAR data demonstrate the effectiveness and robustness of the proposed detector in the defocusing SAR images.

Researching a Moving Target Detection Method Based on Magnetic Flux Induction Technology

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1967
Author(s):  
Chaoqun Xu ◽  
Li Yang ◽  
Kui Huang ◽  
Yang Gao ◽  
Shaohua Zhang ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Magnetic Dipole ◽  
Target Detection ◽  
Electromotive Force ◽  
Detection Method ◽  
Field Tests ◽  
Moving Target ◽  
Moving Targets ◽  
Moving Target Detection ◽  
Modern Warfare

The ocean is a very important arena in modern warfare where all marine powers deploy their military forces. Due to the complex environment of the ocean, underwater equipment has become a very threatening means of surprise attack in modern warfare. Therefore, the timely and effective detection of underwater moving targets is the key to obtaining warfare advantages and has important strategic significance for national security. In this paper, magnetic flux induction technology was studied with regard to the difficulty of detecting underwater concealed moving targets. Firstly, the characteristics of a magnetic target were analyzed and an equivalent magnetic dipole model was established. Secondly, the structure of the rectangular induction coil was designed according to the model, and the relationship between the target’s magnetism and the detection signal was deduced. The variation curves of the magnetic flux and the electromotive force induced in the coil were calculated by using the numerical simulation method, and the effects of the different motion parameters of the magnetic dipole and the size parameters of the coil on the induced electromotive force were analyzed. Finally, combined with the wavelet threshold filter, a series of field tests were carried out using ships of different materials in shallow water in order to verify the moving target detection method based on magnetic flux induction technology. The results showed that this method has an obvious response to moving targets and can effectively capture target signals, which verifies the feasibility of the magnetic flux induction detection technology.

scholarly journals Phase-Based GLRT Detection of Moving Targets with Pixel Tracking in Low-Resolution SAR Image Sequences

2021 ◽  
Vol 13 (19) ◽  
pp. 3855
Author(s):  
Yulun Li ◽  
Chunsheng Li ◽  
Xiaodong Peng ◽  
Shuo Li ◽  
Hongcheng Zeng ◽  
...  
Keyword(s):  
Image Sequences ◽  
Moving Target ◽  
Ratio Test ◽  
Moving Targets ◽  
Low Resolution ◽  
Motion Signal ◽  
Resolution Imaging ◽  
Noise Statistics ◽  
The Cost ◽  
Area Monitoring

Spaceborne synthetic aperture radar (SAR) can provide ground area monitoring with large coverage. However, achieving a wide observation scope comes at the cost of resolution reduction owing to the trade-off between these parameters in conventional SAR. In low-resolution imaging, the moving target appears unresolved, weakly scattered, and slow moving in the image sequence, which can be generated by the subaperture technique. This article proposes a novel moving target detection method. First, interferometric phase statistics are combined with the generalized likelihood ratio test detector. A pixel tracking strategy is further exploited to determine whether a motion signal is present. These methods rely on the approximation of both clutter and noise statistics using Gaussian distributions in a low-resolution scenario. In addition, the motion signals are imaged with a subpixel offset. The proposed method is primarily validated using four real image sequences from TerraSAR-X data, which represent two types of homogeneous areas. The results reveal that moving targets can be detected in nearby areas using this strategy. The method is compared with the stack averaged coherence change detection and particle-filter-based tracking strategies.

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