摘要 :
Millimeter wave imaging radar is indispensible for collision avoidance of self-driving system, especially in optically blurred visions. The range points migration (RPM) is one of the most promising imaging algorithms, which provid...
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Millimeter wave imaging radar is indispensible for collision avoidance of self-driving system, especially in optically blurred visions. The range points migration (RPM) is one of the most promising imaging algorithms, which provides a number of advantages from synthetic aperture radar (SAR), in terms of accuracy, computational complexity, and potential for multifunctional imaging. The inherent problem in the RPM is that it suffers from lower angular resolution in narrower frequency band even if higher frequency e.g. millimeter wave, signal is exploited. To address this problem, the k-space decomposition based RPM has been developed. This paper focuses on the experimental validation of this method using the X-band or millimeter wave radar system, and demonstrated that our method significantly enhances the reconstruction accuracy in three-dimensional images for the two simple spheres and realistic vehicle targets,
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摘要 :
Millimeter wave imaging radar is indispensible for collision avoidance of self-driving system, especially in optically blurred visions. The range points migration (RPM) is one of the most promising imaging algorithms, which provid...
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Millimeter wave imaging radar is indispensible for collision avoidance of self-driving system, especially in optically blurred visions. The range points migration (RPM) is one of the most promising imaging algorithms, which provides a number of advantages from synthetic aperture radar (SAR), in terms of accuracy, computational complexity, and potential for multifunctional imaging. The inherent problem in the RPM is that it suffers from lower angular resolution in narrower frequency band even if higher frequency e.g. millimeter wave, signal is exploited. To address this problem, the k-space decomposition based RPM has been developed. This paper focuses on the experimental validation of this method using the X-band or millimeter wave radar system, and demonstrated that our method significantly enhances the reconstruction accuracy in three-dimensional images for the two simple spheres and realistic vehicle targets,
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摘要 :
With the requirements of radar resolution improving, the aperture of traditional radar has become the bottleneck of its development. In order to overcome this problem, phased array radar and virtual aperture radar are proposed. Vi...
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With the requirements of radar resolution improving, the aperture of traditional radar has become the bottleneck of its development. In order to overcome this problem, phased array radar and virtual aperture radar are proposed. Virtual Aperture Radar can be divided into Synthetic Aperture Radar (SAR) and Inverse Synthetic Aperture Radar (ISAR). The ISAR has the advantages of all-day, all-weather, long-distance, and high resolution, and is widely used in military and civil fields. This paper first briefly introduces the principle of ISAR imaging, the concepts of range resolution and azimuth resolution, then introduces the common methods of envelope alignment and self-focusing, and finally analyzes several ISAR imaging methods, such as large angle imaging algorithm, compressed sensing imaging algorithm, and micromotion target imaging algorithm.
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摘要 :
With the requirements of radar resolution improving, the aperture of traditional radar has become the bottleneck of its development. In order to overcome this problem, phased array radar and virtual aperture radar are proposed. Vi...
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With the requirements of radar resolution improving, the aperture of traditional radar has become the bottleneck of its development. In order to overcome this problem, phased array radar and virtual aperture radar are proposed. Virtual Aperture Radar can be divided into Synthetic Aperture Radar (SAR) and Inverse Synthetic Aperture Radar (ISAR). The ISAR has the advantages of all-day, all-weather, long-distance, and high resolution, and is widely used in military and civil fields. This paper first briefly introduces the principle of ISAR imaging, the concepts of range resolution and azimuth resolution, then introduces the common methods of envelope alignment and self-focusing, and finally analyzes several ISAR imaging methods, such as large angle imaging algorithm, compressed sensing imaging algorithm, and micromotion target imaging algorithm.
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摘要 :
ISAR 2D imaging is obtained by projecting the 3D structure target onto a 2D imaging plane. The angle between the imaging plane and the target spinning axis has a great influence on the projection result. Generally, this angle is n...
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ISAR 2D imaging is obtained by projecting the 3D structure target onto a 2D imaging plane. The angle between the imaging plane and the target spinning axis has a great influence on the projection result. Generally, this angle is neglected, which results in the target imaging has smaller size than the real target. This is not conducive to the further application of target detection and target recognition. In a short observation time, this angle cannot be estimated by monostatic radar. In order to solve such a problem, this letter proposes a method using bistatic radar to estimate the angle and accomplish accurate calibration. First, bistatic ISAR model and bistatic echo signal of spinning target are modeled. Then combining monostatic and bistatic 2D imaging, the angle can be calculated based on several prominent scatterers. Recalibration is performed based on this angle. Finally, the effectiveness of the proposed method is verified by different simulation experiments.
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摘要 :
ISAR 2D imaging is obtained by projecting the 3D structure target onto a 2D imaging plane. The angle between the imaging plane and the target spinning axis has a great influence on the projection result. Generally, this angle is n...
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ISAR 2D imaging is obtained by projecting the 3D structure target onto a 2D imaging plane. The angle between the imaging plane and the target spinning axis has a great influence on the projection result. Generally, this angle is neglected, which results in the target imaging has smaller size than the real target. This is not conducive to the further application of target detection and target recognition. In a short observation time, this angle cannot be estimated by monostatic radar. In order to solve such a problem, this letter proposes a method using bistatic radar to estimate the angle and accomplish accurate calibration. First, bistatic ISAR model and bistatic echo signal of spinning target are modeled. Then combining monostatic and bistatic 2D imaging, the angle can be calculated based on several prominent scatterers. Recalibration is performed based on this angle. Finally, the effectiveness of the proposed method is verified by different simulation experiments.
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摘要 :
In this paper, we review recent and emerging Synthetic Aperture Radar (SAR) applications using mm-Wave radar, ranging from concealed item detection to autonomous systems. Furthermore, relevant machine learning (ML) concepts are in...
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In this paper, we review recent and emerging Synthetic Aperture Radar (SAR) applications using mm-Wave radar, ranging from concealed item detection to autonomous systems. Furthermore, relevant machine learning (ML) concepts are introduced and the review of ML applications in high-resolution mmWave SAR image enhancement and generation are presented. The paper is concluded with challenges and expectations of mmWave SAR imaging with emphasis on autonomous vehicles.
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摘要 :
In this paper, we review recent and emerging Synthetic Aperture Radar (SAR) applications using mm-Wave radar, ranging from concealed item detection to autonomous systems. Furthermore, relevant machine learning (ML) concepts are in...
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In this paper, we review recent and emerging Synthetic Aperture Radar (SAR) applications using mm-Wave radar, ranging from concealed item detection to autonomous systems. Furthermore, relevant machine learning (ML) concepts are introduced and the review of ML applications in high-resolution mmWave SAR image enhancement and generation are presented. The paper is concluded with challenges and expectations of mmWave SAR imaging with emphasis on autonomous vehicles.
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摘要 :
Forward-looking imaging systems are mainly divided into phased-array (PA) radar and multiple-input-multiple-output (MIMO) radar according to whether the transmitted signals are coherent or not. Since PA radar can improve the signa...
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Forward-looking imaging systems are mainly divided into phased-array (PA) radar and multiple-input-multiple-output (MIMO) radar according to whether the transmitted signals are coherent or not. Since PA radar can improve the signal-to-noise ratio (SNR) through beamforming, while MIMO radar can achieve higher spatial resolution through channel separation at the receiver. In this paper, the noise-robustness and super-resolution performance of the two systems are analyzed. A fair comparison is conducted under the equal conditions, including algorithm, hardware, etc. We use a half-wavelength uniform array to transmit linear frequency modulation (LFM) signals for PA radar and orthogonal signals for MIMO radar. We first establishes signal models of PA system and MIMO system respectively, where the sparse Bayesian learning algorithm is used for the scene imaging. The simulation results show that the imaging quality of phased array radar is better than that of MIMO radar under low SNR, but worse than MIMO radar under high SNR, which shows that the PA radar is more suitable for imaging under low SNR, while MIMO radar is better under high SNR.
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摘要 :
In this paper, a novel 3-D imaging method of aerospace targets based on linear array radar is proposed. The traditional ISAR imaging can only show the scattering centers’ projection on the imaging plane, which is hard to be used ...
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In this paper, a novel 3-D imaging method of aerospace targets based on linear array radar is proposed. The traditional ISAR imaging can only show the scattering centers’ projection on the imaging plane, which is hard to be used for target recognition. To overcome this shortcoming, this paper proposes realizing 3-D imaging by a linear array. The key parameters of linear array radar are obtained by analyzing the relationship between of the azimuth ambiguity and the resolution. In the far-field condition, the resolutions of the target image in three dimensions including range, azimuth and height are obtained by using the backward projection algorithm. Experiment based on simulated data shows that the method can achieve accurate 3-D imaging of space objects and have good performance.
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