Refocusing and Motion Parameter Estimation for Ground Moving Targets Based on Improved Axis Rotation-Time Reversal Transform

et al. 2019

IET signal process.

In this study, a ground moving target focusing and motion parameter estimation method based on modified secondorder keystone transform (MSOKT) have been proposed for a synthetic aperture radar. Firstly, a cross-track velocity matching compensation function is derived to remove range walk migration and estimate the cross-track velocity of the moving target. Secondly, an MSOKT is proposed to remove the range curvature and Doppler frequency migration simultaneously. Lastly, a well-focused result of the moving target is obtained, and the motion parameters of the moving target are estimated. Compared with the traditional KT-based method, the proposed method works well in situations where Doppler centre blur and Doppler spectrum ambiguity are present. The computational complexity of the proposed method is considerably lower than that of the traditional optimum method, such as Radon-Lv's distribution. Simulation and real data processing results validate the effectiveness of the proposed method.

Section: Proposed Methods Descriptionmentioning

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Ground moving target focusing and motion parameter estimation method via MSOKT for synthetic aperture radar

Wan

Zhou

et al. 2019

IET signal process.

“…Note that there is LRCM brought by the azimuth position. In order to correct the LRCM, the one-step keystone transform is adopted, which is shown below [26,27]:…”

Section: Imaging Processing For the Moving Targetmentioning

confidence: 99%

Ground Moving Target Indication for the Geosynchronous-Low Earth Orbit Bistatic Multichannel SAR System

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

Gao

Xing

et al. 2021

In this paper, an effective clutter suppression and moving target imaging approach is proposed for the geosynchronous-low earth orbit (GEO-LEO) bi-static multi-channel SAR system, which is robust for the fast moving target with Doppler centroid ambiguity. For the GEO-LEO bi-static multi-channel SAR system, the characteristic of baseline with azimuth invariant in Doppler Fourier transform domain isn't tenable. It is difficulty to implement clutter suppression by the unified baseline compensation in azimuth Doppler Fourier transform domain. Fortunately, we discover that the baseline can be approximately regarded as a constant in chirp Fourier transform domain for the GEO-LEO bi-static multi-channel SAR system. Hence, the corresponding baseline compensation can be achieved in the azimuth chirp Fourier transform domain for the clutter. With an orthogonality vector of clutter, the clutter can be well-suppressed and the moving target is extracted. After that, the moving target imaging approach is developed with the baseband Doppler centroid estimation and Doppler ambiguity number estimation. Finally, the theoretical investigations and the proposed approach in this paper is validated by some the experiments, where the experiments for clutter suppression and experiments for fast moving targets are included. Especially, an experiment with real SAR scattering scene is involved. In addition, some discussions for blind velocity targets are presented. 1 IndexTerms-bistatic multi-channel SAR, the geosynchronous-low earth orbit (GEO-LEO), clutter suppression, blind velocity, chirp Fourier transform, Doppler centroid estimation, Doppler centroid ambiguity.

“…W. A. Kuperman et al [20,21] verified the focusing ability of TR in real acoustic environments with ocean experiments. More recently, there is a growing research on TR in several applications domains, such as detection [22,23], communication [24,25], localization [26,27], or imaging [28]. For ranging system, time reversal methods can be divided into three categories, i.e., active time reversal (ATR) [29], passive time reversal (PTR) [30], and active virtual time reversal (AVTR) [31].…”

Section: Introductionmentioning

confidence: 99%

Pulse Ranging Method Based on Active Virtual Time Reversal in Underwater Multi-Path Channel

Wang

Yao

2020

JMSE

Aiming at improving the accuracy of pulse ranging measurement in underwater multi-path environment, this paper proposes a novel pulse ranging algorithm based on active virtual time reversal (AVTR). By using the focusing characteristics of AVTR, the received signal can be focused at the receiving end, which eliminates the negative influence of multiple pseudo-peaks. In order to extract the received signal, we propose an energy-based adaptive windowed method which preserves the signal focus peak while truncates the side peak component. Numerical simulations are provided and outfield experiments are conducted. The results demonstrate the effectiveness of the proposed method comparing with correlation-based method.