scholarly journals Moving Target Imaging Using GNSS-Based Passive Bistatic Synthetic Aperture Radar

2020 ◽  
Vol 12 (20) ◽  
pp. 3356
Author(s):  
Zhen-Yu He ◽  
Yang Yang ◽  
Wu Chen ◽  
Duo-Jie Weng
Keyword(s):  
Parameter Estimation ◽  
Cell Migration ◽  
Synthetic Aperture ◽  
Moving Target ◽  
Chirp Rate ◽  
Range Cell ◽  
Target Imaging ◽  
Moving Target Imaging ◽  
Bistatic Synthetic Aperture Radar ◽  
Range Cell Migration

Current studies of global navigation satellite systems (GNSS)-based bistatic synthetic aperture radar (GNSS-SAR) is focused on static objects on land. However, moving target imaging is also very significant for modern SAR systems. Imaging a moving target has two main problems. One is the unknown range cell migration; the other is the motion parameter estimation, such as the target’s velocity. This paper proposes a moving target imaging formation algorithm for GNSS-SAR. First, an approximate bistatic range history is derived to describe the phase variation of the target signal along the azimuth time. Then, a keystone transform is employed to correct the range cell migration. To address the motion parameter estimation, a chirp rate estimation method based on short-time Fourier transform and random sample consensus is proposed with high processing efficiency and robust estimation errors in low signal-to-noise ratio scenes. The estimated chirp rate can calculate the target’s velocity. Finally, azimuth compression derivation is performed to accomplish GNSS-SAR imaging. A maritime experimental campaign is conducted to validate the effectiveness of the proposed algorithm. The two cargo ships in the SAR images have good accordance with the ground truth in terms of the target-to-receiver vertical distances along the range and the ships’ length along the cross-range.

scholarly journals Imaging Formation Algorithm of the Ground and Space-Borne Hybrid BiSAR Based on Parameters Estimation from Direct Signal

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Qingjun Zhang ◽  
Cheng Hu ◽  
Lixin Wu ◽  
Tao Zeng ◽  
Teng Long
Keyword(s):  
Cell Migration ◽  
Parameters Estimation ◽  
Chirp Rate ◽  
Limited Information ◽  
Direct Signal ◽  
Range Cell ◽  
Centroid Frequency ◽  
Bistatic Synthetic Aperture Radar ◽  
Range Cell Migration ◽  
Peak Phase

This paper proposes a novel image formation algorithm for the bistatic synthetic aperture radar (BiSAR) with the configuration of a noncooperative transmitter and a stationary receiver in which the traditional imaging algorithm failed because the necessary imaging parameters cannot be estimated from the limited information from the noncooperative data provider. In the new algorithm, the essential parameters for imaging, such as squint angle, Doppler centroid, and Doppler chirp-rate, will be estimated by full exploration of the recorded direct signal (direct signal is the echo from satellite to stationary receiver directly) from the transmitter. The Doppler chirp-rate is retrieved by modeling the peak phase of direct signal as a quadratic polynomial. The Doppler centroid frequency and the squint angle can be derived from the image contrast optimization. Then the range focusing, the range cell migration correction (RCMC), and the azimuth focusing are implemented by secondary range compression (SRC) and the range cell migration, respectively. At last, the proposed algorithm is validated by imaging of the BiSAR experiment configured with china YAOGAN 10 SAR as the transmitter and the receiver platform located on a building at a height of 109 m in Jiangsu province. The experiment image with geometric correction shows good accordance with local Google images.

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.

scholarly journals Analysis of Moving Object Imaging from Compressively Sensed SAR Data in the Presence of Dictionary Mismatch

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Ahmed Shaharyar Khwaja ◽  
Muhammad Naeem ◽  
Alagan Anpalagan
Keyword(s):  
Iterative Scheme ◽  
Reconstruction Error ◽  
Synthetic Aperture ◽  
Moving Target ◽  
Target Imaging ◽  
Cause Of Error ◽  
Moving Target Imaging ◽  
Velocity Mismatch ◽  
Object Imaging ◽  
Better Than

We present compressed sensing (CS) synthetic aperture radar (SAR) moving target imaging in the presence of dictionary mismatch. Unlike existing work on CS SAR moving target imaging, we analyze the sensitivity of the imaging process to the mismatch and present an iterative scheme to cope with dictionary mismatch. We analyze and investigate the effects of mismatch in range and azimuth positions, as well as range velocity. The analysis reveals that the reconstruction error increases with the mismatch and range velocity mismatch is the major cause of error. Instead of using traditional Laplacian prior (LP), we use Gaussian-Bernoulli prior (GBP) for CS SAR imaging mismatch. The results show that the performance of GBP is much better than LP. We also provide the Cramer-Rao Bounds (CRB) that demonstrate theoretically the lowering of mean square error between actual and reconstructed result by using the GBP. We show that a combination of an upsampled dictionary and the GBP for reconstruction can deal with position mismatch effectively. We further present an iterative scheme to deal with the range velocity mismatch. Numerical and simulation examples demonstrate the accuracy of the analysis as well as the effectiveness of the proposed upsampling and iterative scheme.

Presenting a New Technique for Multi-Target Tracking in Inverse Synthetic Aperture Radar based on PHD Filter in the Presence of Clutters

Frequenz ◽  
2018 ◽  
Vol 72 (7-8) ◽  
pp. 391-399 ◽  
Author(s):  
Hamid Dehghani ◽  
Navid Daryasafar
Keyword(s):  
Cell Migration ◽  
Synthetic Aperture Radar ◽  
Synthetic Aperture ◽  
Moving Targets ◽  
Inverse Synthetic Aperture Radar ◽  
Probability Hypothesis Density ◽  
Implementation Phase ◽  
Range Cell ◽  
Range Cell Migration ◽  
Aperture Radar

Abstract Using Probability Hypothesis Density (PHD) filtering, a novel approach is proposed in this paper for simultaneous tracking of multiple moving targets in received data by Inverse Synthetic Aperture Radar (ISAR) system. Since PHD filtering approach is implemented successively in prediction and update steps, its performance quality will obviously be higher in “Spotlight” imaging mode than in “Stripmap”. Thus, its application to Spotlight mode is generally more logical. The idea to integrate tracking capability into ISAR system processor is to sort radar received data to correct Range Cell Migration (RCM) prior to tracking operations. Clearly, Range Cell Migration Compensation (RCMC) approach is different from this approach in image formation process, in terms of their implementation phase. However, they are implemented in a similar way. As simulation results reveal, applying Range Cell Migration Compensation to the raw data received by ISAR before tracking operation, results in high quality tracking of moving targets.

Sign in / Sign up

Export Citation Format

Share Document