Estimation and correction of vibration-induced range cell migration for FMCW synthetic aperture ladar

2020 ◽  
Vol 59 (9) ◽  
pp. 2874
Author(s):  
Guangzuo Li ◽  
Zenghui Zhang ◽  
Yifei Zhang ◽  
Sujuan Fang ◽  
Wen Hong ◽  
...  
Keyword(s):  
Cell Migration ◽  
Synthetic Aperture ◽  
Range Cell ◽  
Range Cell Migration ◽  
Estimation And Correction

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.

scholarly journals High-Resolution Squinted SAR Imaging Algorithm Applied in the Near-Field Environment

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Shijia Wang ◽  
Shibo Wang ◽  
Wanli Liu
Keyword(s):  
Cell Migration ◽  
Near Field ◽  
Synthetic Aperture ◽  
Distortion Compensation ◽  
Imaging Algorithm ◽  
Field Environment ◽  
Imaging Result ◽  
Range Cell ◽  
Sar Imaging ◽  
Range Cell Migration

In the squinted synthetic aperture radar (SAR) imaging of the near-field environment, range-dependent characteristic of squint angle cannot be ignored, which causes azimuth-dependent range cell migration (RCM) after linear range walk correction (LRWC). In this study, an efficient SAR imaging algorithm applied in the near-field environment is proposed. In the processing of the range focusing, LRWC is firstly used to remove the linear RCM. Then, the residual LRCM is expanded into azimuth-invariant and azimuth-variant terms in consideration of the residual LRCM of azimuth-dependent. Range cell migration azimuth scaling (RCMAS) is designed to remove the azimuth-variant term before secondary range compression (SRC) and range compression (RC). In the azimuth focusing, azimuth distortion compensation (ADC) is performed to compensate the azimuth distortion, following which azimuth nonlinear chirp scaling (ANCS) is applied to equalize the frequency modulation (FM) rate for azimuth compression (AC). The simulated results show that more accurate and improved imaging result can be obtained with the proposed algorithm.

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.

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