scholarly journals An Efficient Maritime Target Joint Detection and Imaging Method with Airborne ISAR System

2022 ◽  
Vol 14 (1) ◽  
pp. 193
Author(s):  
Haodong Li ◽  
Guisheng Liao ◽  
Jingwei Xu ◽  
Lan Lan
Keyword(s):  
Target Detection ◽  
Target Location ◽  
Doppler Frequency ◽  
Target Range ◽  
Imaging Method ◽  
Clutter Suppression ◽  
Range Resolution ◽  
Target Imaging ◽  
Isar Imaging ◽  
Imaging Approach

In this paper, a joint maritime moving target detection and imaging approach, referred to as the fast inverse synthetic aperture radar (ISAR) imaging approach, based on the multi-resolution space−time adaptive processing (STAP), is proposed to improve the target detection performance and the target imaging efficiency in an airborne radar system. In the target detection stage, the sub-band STAP is introduced to improve the robustness of clutter suppression and to enhance the target output power with the decreased range resolution, by which the coarse estimation of target range-Doppler (R-D) location is obtained as the prior knowledge. In the following target imaging stage, the ISAR imaging is applied in the localized R-D zone surrounding with the target location. However, it is difficult to directly apply ISAR imaging with the conventional R-D algorithm because the slow-moving maritime target cannot be separated from the clutter interference in the Doppler frequency dimension. In this regard, the full-band STAP is applied in the R-D two-dimensional frequency domain for the simultaneous clutter suppression and high-resolution ISAR imaging, in which the envelope alignment and phase compensation are achieved by adaptive match filtering with the target Doppler frequency coarse estimation. Moreover, the reduced-dimension STAP applied in the target-surrounded localized Doppler frequency zone gives facilities for alleviating the computation burden. Simulation results corroborate the effectiveness of the proposed method.

A New ISAR Imaging Method of Ballistic Midcourse Target

2011 ◽  
Vol 65 ◽  
pp. 485-490
Author(s):  
Teng Lei ◽  
Jin Mang Liu ◽  
Gang Wang ◽  
Song Li
Keyword(s):  
Azimuth Angle ◽  
Imaging Method ◽  
Cross Term ◽  
Imaging Algorithm ◽  
Sparse Decomposition ◽  
Range Resolution ◽  
Range Cell ◽  
Target Imaging ◽  
Isar Imaging ◽  
Micro Motion

A new micro-motion ISAR imaging algorithm based on the MP sparse decomposition is proposed in this paper. The algorithm use the changes of azimuth angle caused by micro-motion to achieve high cross range resolution, and decompose the echoes of the same range cell before Wigner-Ville transformation to eliminate the cross-term interference. Compared with the traditional Range-Doppler algorithm and the Wigner-Ville imaging algorithm, the new algorithm considered here exhibits better imaging precision and is without cross-term interference. The simulated results have demonstrated that it is an effective method for the micro-motion target imaging.

scholarly journals Low-Altitude and Slow-Speed Small Target Detection Based on Spectrum Zoom Processing

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xuwang Zhang ◽  
Songtao Lu ◽  
Jinping Sun ◽  
Wei Shangguan
Keyword(s):  
Target Detection ◽  
Doppler Frequency ◽  
Real Data ◽  
Detection Algorithm ◽  
Clutter Suppression ◽  
Slow Speed ◽  
Small Target Detection ◽  
Ground Clutter ◽  
Radar Systems ◽  
Low Altitude

This paper proposes a spectrum zoom processing based target detection algorithm for detecting the weak echo of low-altitude and slow-speed small (LSS) targets in heavy ground clutter environments, which can be used to retrofit the existing radar systems. With the existing range-Doppler frequency images, the proposed method firstly concatenates the data from the same Doppler frequency slot of different images and then applies the spectrum zoom processing. After performing the clutter suppression, the target detection can be finally implemented. Through the theoretical analysis and real data verification, it is shown that the proposed algorithm can obtain a preferable spectrum zoom result and improve the signal-to-clutter ratio (SCR) with a very low computational load.

Micro-Motion ISAR Imaging Method Based on MP Sparse Decomposition for Fast Moving Target

2013 ◽  
Vol 760-762 ◽  
pp. 1482-1485 ◽  
Author(s):  
Jian Gong ◽  
Teng Lei ◽  
Zhi Long Li ◽  
Chuang Li
Keyword(s):  
Azimuth Angle ◽  
Imaging Method ◽  
Moving Target ◽  
Cross Term ◽  
Imaging Algorithm ◽  
Sparse Decomposition ◽  
Range Resolution ◽  
Range Cell ◽  
Isar Imaging ◽  
Micro Motion

In this paper, a new micro-motion ISAR imaging algorithm is proposed, which achieve high cross range resolution by using the changes of azimuth angle caused by micro-motion. Before Wigner-Ville transformation to eliminate the cross-term interference, the echoes of the same range cell are decomposed. Comparing to traditional the Wigner-Ville imaging algorithm and Range-Doppler algorithm, this new algorithm in this paper has better imaging precision and no cross-term interference is existed. At last, the effectivity of the proposed algorithm is demonstrated by the simulated results.

scholarly journals An Inter-Subband Processing Algorithm for Complex Clutter Suppression in Passive Bistatic Radar

2021 ◽  
Vol 13 (23) ◽  
pp. 4954
Author(s):  
Luo Zuo ◽  
Jun Wang ◽  
Jinxin Sui ◽  
Nan Li
Keyword(s):  
Frequency Domain ◽  
Target Detection ◽  
Detection Performance ◽  
Bistatic Radar ◽  
Time Varying ◽  
Clutter Suppression ◽  
Range Resolution ◽  
Novel Method ◽  
Subband Processing ◽  
Passive Bistatic Radar

Clutter suppression is a challenging problem for passive bistatic radar systems, given the complexity of actual clutter scenarios (stationary, time-varying and fractional-order clutter). Such complex clutter induces intense sidelobes in the entire range-Doppler plane and thus degrades target-detection performance, especially for low-observable targets. In this paper, a novel method, denominated as the batch version of the extensive cancellation algorithm (ECA) in the frequency domain (ECA-FB), is presented for the first time, to suppress stationary clutter and its sidelobes. Specifically, in this method, the received signal is first divided into short batches in the frequency domain to coarsen the range resolution, and then the clutter is removed over each batch via ECA. Further, to suppress the time-varying clutter, a Doppler-shifted version of ECA-FB (ECA-FBD) is proposed. Compared with the popular ECA and ECA-B methods, the proposed ECA-FB and ECA-FBD obtained superior complex clutter suppression and slow-moving target detection performance with lower computational complexity. A series of simulation and experimental results are provided to demonstrate the validity of the proposed methods.

scholarly journals A Fast Bistatic ISAR Imaging Approach for Rapidly Spinning Targets via Exploiting SAR Technique

2020 ◽  
Vol 12 (13) ◽  
pp. 2077
Author(s):  
Zhijun Yang ◽  
Dong Li ◽  
Xiaoheng Tan ◽  
Hongqing Liu ◽  
Guisheng Liao
Keyword(s):  
Synthetic Aperture Radar ◽  
Signal To Noise Ratio ◽  
Doppler Frequency ◽  
Synthetic Aperture ◽  
Coherent Integration ◽  
Range Cell ◽  
Isar Imaging ◽  
Imaging Approach ◽  
Spinning Targets ◽  
Aperture Radar

Because of the large range of cell migration (RCM) and nonstationary Doppler frequency modulation (DFM) produced by non-cooperative targets with rapid spinning motions, it is difficult to efficiently generate a well-focused bistatic inverse synthetic aperture radar (ISAR) by use of the conventional imaging algorithms. Utilizing the property of the inherent azimuth spatial invariance in strip-map synthetic aperture radar (SAR) imaging mode, in this work, an efficient bistatic ISAR imaging approach based on circular shift operation in the range-Doppler (RD) domain is proposed. First, echoes of rapidly spinning targets are transformed into the RD domain, whose exact analytical is derived on the basis of the principle of stationary phase (POSP). Second, the RCM is corrected by using an efficient circular shift operation in the RD domain. By doing so, the energies of a scatterer that span multiple range cells are concentrated into the same range cell, and the time-varying DFM can also be compensated along the rotating radius direction. Compared with existing methods, the proposed method has advantages in its computational complexity, avoiding the interpolation and multi-dimensional search operation, and in its satisfactory imaging performance under low signal to noise ratio (SNR) conditions thanks to the two-dimensional coherent integration gain utilized. Finally, several numerical simulations are conducted to show the validity of the proposed algorithm.

scholarly journals Robust Clutter Suppression and Ground Moving Target Imaging Method for a Multichannel SAR with High-Squint Angle Mounted on Hypersonic Vehicle

2021 ◽  
Vol 13 (11) ◽  
pp. 2051
Author(s):  
Jiusheng Han ◽  
Yunhe Cao ◽  
Tat-Soon Yeo ◽  
Fengfei Wang
Keyword(s):  
Hypersonic Vehicle ◽  
Imaging Method ◽  
Moving Target ◽  
Clutter Suppression ◽  
Range Cell ◽  
Target Imaging ◽  
Moving Target Imaging ◽  
Suppression Method ◽  
Range Cell Migration ◽  
First Order Phase

This paper investigates a robust clutter suppression and detection of ground moving target (GMT) imaging method for a multichannel synthetic aperture radar (MC-SAR) with high-squint angle mounted on hypersonic vehicle (HSV). A modified coarse-focused method with cubic chirp Fourier transform (CFT) is explored first that permits the coarsely focused imageries to be recovered, thus alleviated the impacts of GMT Doppler ambiguity and range cell migration (RCM). After that, in combination with joint-pixel model, a robust clutter suppression method which enhances the GMT integration, and improving the accuracy of radial speed (RS) recovery by modifying the matching between the beamformer center and GMT, is proposed. Due to that the first-order phase compensation and RS retrieval are predigested, the proposed algorithm has lower the algorithmic complexity. Finally, the feasibility of our proposed method are verified via experimental results based on simulated and real measured data.

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