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.

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 Focusing of Spotlight Tandem-Configuration Bistatic Data with Frequency Scaling Algorithm

2016 ◽  
Vol 2016 ◽  
pp. 1-15
Author(s):  
Shichao Chen ◽  
Ming Liu ◽  
Jun Wang ◽  
Fugang Lu ◽  
Mengdao Xing
Keyword(s):  
Cell Migration ◽  
Data Processing ◽  
High Precision ◽  
Frequency Scaling ◽  
Tandem Configuration ◽  
Imaging Algorithm ◽  
Bistatic Sar ◽  
Range Cell ◽  
Sar Data ◽  
Range Cell Migration

A frequency scaling (FS) imaging algorithm is proposed for spotlight bistatic SAR data processing. Range cell migration correction (RCMC) is realized through phase multiplication. The proposed algorithm is insensitive to the length of the baseline due to the high precision of the point target (PT) spectrum that we are based on. It is capable of handling bistatic SAR data with a large baseline to range ratio. The algorithms suitable for small and high squint angles are both discussed according to whether the range dependence of the second range compression (SRC) can be neglected or not. Simulated experiments validate the effectiveness of the proposed algorithm.

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

scholarly journals Squint Mode GEO SAR Imaging Using Bulk Range Walk Correction on Received Signals

2018 ◽  
Vol 11 (1) ◽  
pp. 17
Author(s):  
Jiwen Geng ◽  
Ze Yu ◽  
Chunsheng Li ◽  
Wei Liu
Keyword(s):  
Imaging Method ◽  
Sensing Applications ◽  
Imaging Result ◽  
Range Cell ◽  
Sar Imaging ◽  
Disaster Monitoring ◽  
Imaging Mode ◽  
Range Cell Migration ◽  
Long Term Observation

Geosynchronous synthetic aperture radar (GEO SAR) has the potential for conducting long-term observation of target zones, which is essential for remote sensing applications such as disaster monitoring and vegetation measurements. The squint imaging mode is crucial for long-term observation using GEO SAR. However, this type of SAR imaging is problematic because the squint mode introduces a nonzero range cell walk, which increases the prevalence of invalid data in echoes and intensifies the coupling between the azimuth and range. Therefore, this paper proposes a novel squint mode GEO SAR imaging method based on the correction of the bulk range walk of received signals. Adjusting the starting time of the receiving window significantly reduces the redundancy in echoes. Then, first-order filtering, range cell migration correction, range compression, partial dechirp, and azimuth compression are used to obtain the imaging result. Simulation results for the GEO SAR imaging of Wenchuan County in China demonstrate that the proposed algorithm can achieve a resolution of 5 m within a 30 × 30 km swath over 48% of the orbital period.

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