Integration of Rotation Estimation and High-Order Compensation for Ultrahigh-Resolution Microwave Photonic ISAR Imagery

Yang, Lichao; Xing, Mengdao; Zhang, Lei; Sun, Guang-Cai; Gao, Yuexin; Zhang, Zijing; Bao, Zheng

doi:10.1109/tgrs.2020.2994337

Cited by 32 publications

(10 citation statements)

References 42 publications

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“…Through range frequency resampling, the decoupling of range frequency

{f}_{r}

and virtual slow time quadratic term

{\tau }_{m}^{2}

can be completed. As

{\omega }^{2}

can be estimated and

{\tau }_{m}^{2}

is known, the authors propose to complete the non‐uniform frequency sampling of the echo by non‐uniform Fourier transform [27].…”

Section: Algorithm Solvingmentioning

confidence: 99%

A bistatic inverse synthetic aperture radar sparse aperture high‐resolution imaging algorithm with migration compensation

Zhu

Guo

et al. 2022

IET Radar Sonar & Navi

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In recent years, bistatic inverse synthetic aperture radar (Bi‐ISAR) imaging of targets with sparse aperture has attracted more and more attention. One of the critical issues is that the Bi‐ISAR imaging of some large targets with rotational motions is prone to migration through resolution cells, which increases the imaging difficulty. In order to enhance the compensation for through resolution cell migration in those scenarios and improve the accuracy and resolution of Bi‐ISAR images under sparse aperture, that is, improving the target recognition of Bi‐ISAR, the authors aimed at the high‐order migration term and the high‐order phase error term and proposed a Bi‐ISAR sparse aperture high‐resolution imaging algorithm based on complex Bayesian compressed sensing and frequency resampling. The algorithm was solved by ‘distributed’ iteration. The migration compensation under the sparse aperture conditions was completed, and the quality of the reconstructed images was improved. Simulation results verified the effectiveness and superiority of the proposed algorithm.

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“…Through range frequency resampling, the decoupling of range frequency

{f}_{r}

and virtual slow time quadratic term

{\tau }_{m}^{2}

can be completed. As

{\omega }^{2}

can be estimated and

{\tau }_{m}^{2}

is known, the authors propose to complete the non‐uniform frequency sampling of the echo by non‐uniform Fourier transform [27].…”

Section: Algorithm Solvingmentioning

confidence: 99%

A bistatic inverse synthetic aperture radar sparse aperture high‐resolution imaging algorithm with migration compensation

Zhu

Guo

et al. 2022

IET Radar Sonar & Navi

View full text Add to dashboard Cite

show abstract

“…In this case, more terms in (3 ) should be considered to acquire accurate range profiles. When the first‐order keystone transform with an eight‐point truncated sinc interpolation is used to compensate for the migration [7 ], the obtained image is shown in Fig. 3 b , where the focusing accuracy is apparently improved for the scatters close to the rotation centre.…”

Section: Isar Imaging With Rd Algorithmmentioning

confidence: 99%

“…Although the RD algorithm is widely used in narrow‐band radar imaging, it may not be the best choice for photonics‐based broadband radar imaging in which the migration effect is serious because of the high range resolution. Migration compensation techniques, such as the keystone transform [7 ], provide possible solutions to this problem, but the compensation accuracy is limited and the increased computation complexity will reduce the imaging speed. On the other hand, radar imaging with time‐domain back‐projection (BP) algorithm can solve the migration problem with accurate coherent accumulation.…”

Section: Introductionmentioning

confidence: 99%

Frequency‐domain versus time‐domain imaging for photonics‐based broadband radar

et al. 2020

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Photonics‐based radar enables a large operation bandwidth that is particularly favourable for high‐resolution synthetic aperture imaging. However, how to implement fast and high‐accuracy imaging with photonics‐based broadband radar is still an open question. In this Letter, the performance of photonics‐based inverse synthetic aperture radar imaging with frequency‐domain and time‐domain algorithms are experimentally investigated and compared. The results show that, frequency‐domain range–Doppler algorithm has fast imaging capability, but the image suffers from defocusing and distortions. Although migration compensation techniques can be applied to improve the imaging accuracy, the imaging speed is significantly reduced. On the other hand, using time‐domain back‐projection (BP) algorithm can achieve well‐focused images, and the imaging speed can be enhanced with fast BP methods. Therefore, the time‐domain imaging method is found to be the best choice for fast and high‐accuracy synthetic aperture imaging with photonics‐based broadband radars.

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“…Motion errors usually consist of an envelope error and a phase one, and both types of errors satisfy the linear mapping relationship, that is, the ratio of the phase error to the envelope error is 4π/. Some researchers calculate the phase error by estimating the envelope error [14][15][16][17], but others convert the phase error estimated by phase autofocusing methods into the envelope error [2,6,18,19]. In the first class methods, the cross-correlation method based on oversampled data of range profiles is employed to estimate the envelope error.…”

Section: Introductionmentioning

confidence: 99%

A High-Resolution Airborne SAR Autofocusing Approach Based on SR-PGA and Subimage Resampling With Precise Hyperbolic Model

Deng

Wang

Sun

et al. 2023

IEEE J. Sel. Top. Appl. Earth Observations Remote Sensing

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High-resolution airborne synthetic aperture radar (SAR) imaging requires long synthetic aperture time (LSAT). However, the LSAT invalidates the Fresnel approximation in the traditional autofocusing method, leaving a residual signal phase in the motion error. To solve the problem, a signal-reconstructionbased phase gradient autofocus (SR-PGA) and a sub-image resampling (SIR) methods are proposed. They are developed on the hyperbolic model. First, a sub-aperture division strategy divides the full-aperture high-order error into multiple low-order sub-aperture errors. Then, the SR-PGA is developed to estimate the sub-aperture error (SPE), in which the precise deramping is reconstructed to eliminate the residual signal phase in the SPE. Third, the SIR is proposed to eliminate residual Doppler-variant shift of the adjacent sub-images, improving the accuracy of the SPE combination. Finally, simulation and actual data processing verify the effectiveness and validity of the algorithm.

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Integration of Rotation Estimation and High-Order Compensation for Ultrahigh-Resolution Microwave Photonic ISAR Imagery

Cited by 32 publications

References 42 publications

A bistatic inverse synthetic aperture radar sparse aperture high‐resolution imaging algorithm with migration compensation

A bistatic inverse synthetic aperture radar sparse aperture high‐resolution imaging algorithm with migration compensation

Frequency‐domain versus time‐domain imaging for photonics‐based broadband radar

A High-Resolution Airborne SAR Autofocusing Approach Based on SR-PGA and Subimage Resampling With Precise Hyperbolic Model

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