High Accuracy Velocity Measurement Based on Keystone Transform Using Entropy Minimization

Dai, Zuoning; Zhang, Xinggan; Fang, Hui; Bai, Yechao

doi:10.1049/cje.2016.06.009

Cited by 14 publications

(13 citation statements)

References 7 publications

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“…In Refs. [10,11], the values of Ricean LOS component change from 1.49-6dB. In this paper, the mean value of K-factor (7.26dB) indicates that the viaduct reduces the strength of the received scatter components, that leads to a high value of K-factor.…”

Section: K-factormentioning

confidence: 70%

Wireless Channel Measurements and Modeling of LTE Broadband System for High‐Speed Railway Scenarios

et al. 2018

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Section: K-factormentioning

confidence: 70%

Wireless Channel Measurements and Modeling of LTE Broadband System for High‐Speed Railway Scenarios

et al. 2018

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“…In these situations, the Doppler spectrum split of moving targets is shown. The Doppler ambiguity of the moving target signal (containing Doppler center blur and spectrum split) results in difficulty in the refocusing of moving targets by the traditional frequency-domain methods, such as transitional KT-, SOKT-and stationary phase-based methods [15,16,[19][20][21][22][23][24]. On this basis, a new method for SAR refocusing of moving targets with Doppler ambiguity is developed to deal with the aforementioned problems.…”

Section: Signal Modelmentioning

confidence: 99%

“…However, they suffer from the problem of high computational complexity. The keystone transform [19][20][21] has been proposed to remove RWM without searching the trajectory of ground moving targets. Although this method can correct RWM without knowing priori motion information of ground moving targets, it suffers from the effect of RCM.…”

Section: Introductionmentioning

confidence: 99%

Refocusing of Ground Moving Targets with Doppler Ambiguity Using Keystone Transform and Modified Second-Order Keystone Transform for Synthetic Aperture Radar

et al. 2021

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Ground moving targets will typically be defocused because of the range migration (RM) and Doppler frequency migration (DFM) caused by the unknown relative motions between the platform of synthetic aperture radar (SAR) and the ground moving targets. The received signal of the ground moving target easily exhibits the Doppler ambiguity, and the Doppler ambiguity leads to the refocusing difficulty of ground moving targets. To address these problems, a SAR refocusing method of ground moving targets with Doppler ambiguity based on modified second-order keystone transform (MSOKT) and keystone transform (KT) is presented in this paper. Firstly, the second-order phase is separated by the time reversing process. Secondly, MSOKT is performed to compensate the range curvature migration and DFM, and then the coefficient of the second-order phase is estimated. Finally, a well-refocused result of the moving target is achieved after KT and the estimated Doppler ambiguity number are used to eliminate residual range walk migration. The proposed method can accurately remove RM and DFM and effectively focus the moving targets without residual correction errors. Moreover, the effects of Doppler ambiguity (including Doppler center blur and spectrum split) and blind speed sidelobe are further avoided. On the basis of the analysis of cross-term for the multiple target case, the identification strategy of spurious peak of cross-term is proposed. Additionally, the developed method can be sped up by nonuniform fast Fourier transform without the interpolation operation. The effectiveness of the proposed method is verified by both airborne and spaceborne real data processing results.

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“…Thus, compared to (21), another benefit of ( 36) is that the smallest dimension of the data matrix is shrunk to reduce the computational load of calculating the spectral norm. There are many algorithms to perform the eigendecomposition of a Hermitian matrix; here we propose using the simple power iteration algorithm since only the largest eigenvalue is needed [44].…”

Section: Efficient Implementationmentioning

confidence: 99%

“…Coherent methods are usually performed usingthe matched filter (MF) bank, e.g., W-Capon, W-APES [16], time-reversing transform [17], [18], scaled inverse Fourier transform [19], modified location rotation transform [20] and iterative adaptive algorithm (IAA), the latter of which is extended to wideband waveforms [9]. Keystone transform along with some focussing criteria can also be applied to the unambiguous velocity extraction [21]- [23]. Another famous coherent integration method is Radon Fourier transform (RFT) achieved by the coupling term compensation and coherent integration.…”

Section: Introductionmentioning

confidence: 99%

Joint Features Extraction for Multiple Moving Targets Using (Ultra-)Wideband FMCW Signals in the Presence of Doppler Ambiguity

Yarovoy

2020

IEEE Trans. Signal Process.

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This article addresses the joint estimation of range, velocity and azimuth for multiple fast-moving targets using (ultra-)wideband (UWB) frequency-modulated continuous-wave (FMCW) radar with a phased array in the presence of Doppler ambiguities. The range migration of moving targets is described with the coupling of the fast-time and slow-time (chirp index), leading to the smearing of the target Doppler spectrum. This phenomenon degrades the performance of conventional detection and estimation techniques. As with range-Doppler processing, the estimation accuracy for direction-of-arrival (DOA) with conventional narrowband-based algorithms significantly degrades if a UWB signal is deployed. For the FMCW waveform, the wideband DOA differs from the narrowband DOA due to an extra coupling term, similar to the range migration problem. A novel spectral normbased algorithm for joint estimation of range, velocity and DOA of fast-moving targets is proposed, taking the appropriate wideband signal model with the coupling terms into account. The proposed spectral norm-based algorithm avoids off-grid peak search and can be easily accelerated with power iteration; it outperforms conventional coherent integration methods in both accuracy and efficiency when using moderate data size. The advantages of the proposed algorithm and its super-resolution capability are validated with numerical simulations.

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High Accuracy Velocity Measurement Based on Keystone Transform Using Entropy Minimization

Cited by 14 publications

References 7 publications

Wireless Channel Measurements and Modeling of LTE Broadband System for High‐Speed Railway Scenarios

Wireless Channel Measurements and Modeling of LTE Broadband System for High‐Speed Railway Scenarios

Refocusing of Ground Moving Targets with Doppler Ambiguity Using Keystone Transform and Modified Second-Order Keystone Transform for Synthetic Aperture Radar

Joint Features Extraction for Multiple Moving Targets Using (Ultra-)Wideband FMCW Signals in the Presence of Doppler Ambiguity

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