Moving target detection of array antennas based on time reversal

Self Cite

Polarisation diversity radar enhances the performance of target detection. Time reversal exploits the multipath effect by adaptively matching propagation channels to improve the signal-to-noise ratio (SNR) and realise high detectability. This work combines polarisation diversity and time-reversal technology to propose a time-reversal detector suitable for a polarisation array radar. The maximum likelihood estimate is carried out for the timevarying channel response to solve the channel mismatch problem, which may cause the degradation of time-reversal performance. In addition, a conventional polarisation detector is developed under the same varying channel scenario to benchmark the timereversal detector, and furthermore, the SNR gain of the time-reversal detector over the conventional detector is derived. Numerical simulations demonstrate the superiority of the time-reversal detector. Both the polarisation detectors proposed can take advantage of the channel variations to improve the detectability, and the greater the energy brought by the channel changes, the better the detection performance achieved.

Section: Poltr-glrt Detectormentioning

confidence: 99%

“…Based on (38), the PolTR-GLRT detector in which the channel responses G and � G are obtained by the maximum likelihood estimate can be derived as follows:…”

Section: Poltr-glrt Detectormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Target detection based on time reversal with polarisation array antennas

Zhang

Chen

Yang

et al. 2021

Self Cite

“…The time reversal [7–11] algorithm can realize the space‐time focussing of the MP signals and effectively improve the radar detection performance. However, the reciprocity condition of the TR algorithm requires that the channel response function remains unchanged during the transmitting and receiving process of the radar antenna.…”

Section: Introductionmentioning

confidence: 99%

Adaptive detection for resolvable multipath signal under heterogeneous clutter

Cao

Fan

et al. 2022

In the urban environment, the radar is easily affected by multipath (MP) returns. The problem of detecting point-like targets in the urban environment with the existence of resolvable MP returns under the background of heterogeneous clutter is addressed. Two adaptive detectors have been devised with a combination of prior information on the environment and echoes of target. The detectors can use the MP echoes in all MP prediction range cells for detection or in some available paths for signal detection by the available path selection algorithm that eliminates the weak signal propagation paths. Remarkably, the proposed decision schemes exhibit the desirable constant false alarm rate property with respect to the unknown parameters of the heterogeneous interference. The performance assessment, conducted on simulated data in terms of detection probability also in comparison with conventional solutions, highlights the effectiveness of the MP exploitation, while the MP signal is strong and shows the detection performance enhancement potential.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

“…However, in actual situations, the scattering environment often changes on a short time scale due to target motion, although this variation may not be significant. For moving targets, authors in [39, 40] studied TR algorithms aimed at detecting targets based on the Doppler frequency in single‐antenna and antenna array systems, respectively, but the channel environment was still assumed to be stationary and reciprocal. For varying channels, the authors in [41] demonstrated that TR is still effective from information theoretic.…”

Section: Introductionmentioning

confidence: 99%

Time reversal detection in a multistatic radar system with a varying environment

Zhang

Chen

Yang

2021

Self Cite

Multistatic radar has the advantage of spatial diversity, but its detection performance is decreased in dense multipath scattering environments. This problem can be solved by using the time reversal (TR) technique to take advantage of the multipath effect to improve target detection; however, this usually requires a stationary channel response that is difficult to achieve in practice. This article studies a TR detection algorithm for a multistatic radar system in a varying multipath channel environment. We establish a varying channel response model and derive a time reversal likelihood ratio test (TR-LRT) detector to utilise the characteristics of multiple paths when the multipath environment is changing during the detection process. We use Monte Carlo simulations and theoretical analysis to show the superior performance of the proposed TR detector compared with a conventional detector. Our proposed TR-LRT detector shows good robustness to environmental variations. Simulation results show that better detection results are achieved in a more severe multipath scattering environment.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.