Moving target detection in HRWS mode

Guo, Xiaojiang; Gao, Yesheng; Liu, Xingzhao

doi:10.1109/igarss.2017.8127165

Cited by 3 publications

(4 citation statements)

References 12 publications

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“…This typical phenomenon is called the scene folding in this paper. According to (21), when the azimuth moment η c characterizing the position of a stationary target exceeds a specific interval, i.e., [− f r /2K a , f r /2K a ], the scene will be folded. Therefore, taking the size of the scene into account, ( 21) is more accurately expressed as…”

Section: Coarse-focused Image Domainmentioning

confidence: 99%

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A Method of Marine Moving Targets Detection in Multi-Channel ScanSAR System

et al. 2020

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Azimuth multi-channel Synthetic Aperture Radar (SAR) system operated in burst mode makes high-resolution ultrawide-swath (HRUS) imaging become a reality. This kind of imaging mode has excellent application value for the maritime scenarios requiring wide-area monitoring. This paper suggests a moving target detection (MTD) method of marine scenes based on sparse recovery, which integrates detection, velocity estimation, and relocation. Firstly, the typical phenomenon of scene folding in the coarse-focused domain is introduced in detail. Given that the spatial distribution of moving vessels is highly sparse, the idea of sparse recovery is utilized to acquire the azimuth time characterizing the position of the moving target reasonably. Subsequently, the radial velocity and position information about the targets are obtained simultaneously. What makes the proposed method effective are two characteristics of the moving targets in ocean scenes, high signal-to-clutter ratio (SCR) and sparsity of the spatial distribution. Then, estimation performances under different SCR are analyzed by Monte Carlo experiments. And the actual SCR of the vessels in the ocean scene obtained by GaoFen-3 dual-receive channel mode is invoked as a reference value to verify the effectiveness. Besides, some simulation experiments demonstrate the capability to indicate marine moving targets.

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Section: Coarse-focused Image Domainmentioning

confidence: 99%

“…It reflects in the image as several pairs of false targets. In contrast, the imaging result of the static targets is free from ambiguity after reconstruction [21,22]. If the moving target detection works in the image domain, the false alarm rate will increase considerably.…”

Section: Introductionmentioning

confidence: 99%

A Method of Marine Moving Targets Detection in Multi-Channel ScanSAR System

et al. 2020

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“…The Doppler frequency of the background clutters is located at

f_{normalC} = f_{normala} + l_{n} \cdot PRF

and the spectral peak of the moving target is located at

f_{normalT} = f_{normala} + i \cdot PRF + 2 v_{normalr} / λ

. In [7], unambiguous SAR images of moving targets and clutters can be simultaneously obtained by a digital beamforming (DBF) technique. According to the positions of the clutters, the frequency of the clutters can be easily obtained and thus

{bold-italicA}_{normalC}

will be a known constant.…”

Section: Maximum Likelihood Estimationmentioning

confidence: 99%

Radial velocity estimation of moving target based on maximum likelihood estimation

2018

Self Cite

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For conventional multichannel synthetic aperture radar (SAR) systems, the pulse repetition frequency is greater than the azimuth Doppler bandwidth. Therefore, each receive channel can obtain unambiguous SAR image and the moving target usually overlaps with no more than one clutter. However, for high‐resolution wide‐swath (HRWS) SAR systems, the PRF is usually much less than the Doppler bandwidth and thus the moving target may overlap with quite a few clutters, which will severely affect the estimation of the radial velocity of the moving target. A novel radial velocity estimation method based on maximum likelihood estimation (MLE) for HRWS SAR systems is presented. Even if the moving target overlaps with quite a few clutters, the proposed MLE method can still effectively estimate the radial velocity. In order to reduce the computational load, the proposed method transforms the multi‐dimensional spectral peak searching of MLE into one‐dimensional peak searching and reduces the times of matrix inversion by a block matrix method. Theoretical analysis and experiments demonstrate the feasibility of the proposed method.

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“…However, in traditional single-channel spaceborne SAR, the limitation on the minimum antenna area makes it impossible to enhance the azimuth resolution and enlarge the range swath simultaneously. For this problem, one method is to use azimuth multi-channel technology, that is, to first obtain the radar echo signal with no aliasing of the azimuth spectrum through azimuth multi-channel signal reconstruction and then use standard imaging algorithms to achieve precise focusing, therefore achieving HRWS imaging [13][14][15][16][17]. However, with the continuous improvement in imaging indicators, the number of azimuth channels may increase significantly, and it will be insufficient to rely on azimuth multichannel technology to improve imaging performance.…”

Section: Introductionmentioning

confidence: 99%

Accuracy Improvement of High-Resolution Wide-Swath Spaceborne Synthetic Aperture Radar Imaging with Low Pule Repetition Frequency

Wang,

Ruan,

Zhang

2023

Remote Sensing

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For a single-channel spaceborne synthetic aperture radar (SAR), the usage of a low pulse repetition frequency (PRF) is an effective technical way to extend the range swath. The sub-aperture imaging strategy is usually used to solve the problem of azimuth spectrum aliasing under the condition of a low PRF. However, the required up-sampling processing before the coherent synthesis of sub-images will lead to spectrum discontinuity between adjacent sub-images, which leads to an obvious grating lobe phenomenon after the process of sub-image synthesis, resulting in a significant decrease in image quality. For this issue, a high-resolution wide-swath (HRWS) imaging algorithm for a spaceborne SAR with a low PRF is proposed in this paper based on optimal spectrum shift processing. First, each sub-aperture is imaged using the typical range migration algorithm (RMA), and then all sub-images are up-sampled at the same time. Then, based on the criterion of the minimum grating lobe, the optimal spectrum shift is estimated. Finally, the spectrum of all sub-images is shifted and then all the shifted sub-images are synthesized coherently. The simulation data processing results verify the effectiveness of the proposed method.

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Moving target detection in HRWS mode

Cited by 3 publications

References 12 publications

A Method of Marine Moving Targets Detection in Multi-Channel ScanSAR System

A Method of Marine Moving Targets Detection in Multi-Channel ScanSAR System

Radial velocity estimation of moving target based on maximum likelihood estimation

Accuracy Improvement of High-Resolution Wide-Swath Spaceborne Synthetic Aperture Radar Imaging with Low Pule Repetition Frequency

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