A Novel Azimuth Spectrum Reconstruction and Imaging Method for Moving Targets in Geosynchronous Spaceborne–Airborne Bistatic Multichannel SAR

Zhang, Ying; Xiong, Wei; Dong, Xichao; Hu, Cheng

doi:10.1109/tgrs.2020.2974531

Cited by 25 publications

(23 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, since we first investigated the incomplete echo moving target imaging problem in this paper, our proposed method only considers the uniform motion situation. The incomplete echo SAR imaging for more complex target moving models, or the moving target based on more complex SAR configurations will be a logical next step for our further works [20], [23]- [26].…”

Section: Discussionmentioning

confidence: 99%

SAR Imaging Method for Moving Target With Azimuth Missing Data

Jiang

Wang

Feng

et al. 2022

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

View full text Add to dashboard Cite

To solve the problem of the moving target SAR imaging from an incomplete echo, we proposed a novel SAR imaging method for the moving target with the azimuth missing data (MTIm-AMD). Instead of directly reconstructing the moving target image using the sparse SAR imaging method, we estimate and reconstruct the non-cooperative moving target's complete echo from the azimuth incomplete echo based on its sparsity. At first, the non-cooperative moving target's motion parameters are estimated from the incomplete echo. Then, to ensure that the complete echo can be well reconstructed using the compressed sensing method, these parameters are exploited to design a phase compensation function. Finally, using the reconstructed data, the fine-focused moving target can be obtained via the traditional SAR imaging algorithm. The simulation and experiment data results verify the effectiveness of the proposed MTIm-AMD method and demonstrate that the moving target can be fineimaging when the echo SNR is higher than −20 dB and the azimuth missing ratio (AMR) is less than 70%. This implies that the proposed MTIm-AMD method achieves satisfactory robustness to echo SNR and can handle most AMR cases.

show abstract

Section: Discussionmentioning

confidence: 99%

SAR Imaging Method for Moving Target With Azimuth Missing Data

Jiang

Wang

Feng

et al. 2022

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

View full text Add to dashboard Cite

show abstract

“…In [22], the azimuth aliasing characteristics of GEO-SA-BiSAR were analyzed and multichannel reconstruction technique was applied to suppress the ambiguity. Thereafter, the imaging method [23,24] and moving target imaging [25,26] of GEO-SA-BiSAR were further studied.…”

Section: Introductionmentioning

confidence: 99%

A Novel Frequency-Domain Focusing Method for Geosynchronous Low-Earth-Orbit Bistatic SAR in Sliding-Spotlight Mode

et al. 2022

View full text Add to dashboard Cite

The low-earth-orbit synthetic aperture radar (SAR) can achieve enhanced remote-sensing capabilities by exploiting the large-scale and long-duration beam coverage of a geosynchronous (GEO) SAR illuminator. Different bistatic imaging modes can be implemented by the steering of an antenna beam onboard the LEO receiver, such as high-resolution sliding-spotlight mode. In this paper, the accurate focusing of GEO-LEO bistatic SAR (GEO-LEO BiSAR) in sliding-spotlight mode is investigated. First, the two major problems of the accurate bistatic range model, i.e., curved trajectory within long integration time and ‘stop-and-go’ assumption error, for sliding-spotlight GEO-LEO BiSAR are analyzed. Then, a novel bistatic range model based on equivalent circular orbit trajectory is proposed to accurately represent the range history of GEO-LEO BiSAR in sliding-spotlight mode. Based on the proposed range model, a frequency-domain imaging method is put forward. First, a modified two-step preprocessing method is implemented to remove the Doppler aliasing caused by azimuth variance of Doppler centroid and beam steering. Then, an azimuth trajectory scaling is formulated to remove the azimuth variance of motion parameters due to curved trajectory. A modified frequency-domain imaging method is derived to eliminate the 2-D spatial variance and achieve accurate focusing of the echo data. Finally, imaging results and analysis on both simulated data and real data from an equivalent BiSAR experiment validate the effectiveness of the proposed method.

show abstract

“…To acquire images at fair spatial resolution over a wide swath [1], low pulse repetition frequency is required to avoid range ambiguity. However, the effects of azimuth Doppler ambiguity (ADA) and azimuth spectrum aliasing (ASA) will emerge if the pulse repetition frequency is lower than the Doppler bandwidth of the backscattered signals from the targets [2], resulting in multiple ghost targets and range error.…”

Section: Introductionmentioning

confidence: 99%

“…The ASA issue is more complicated than the ADA issue since a moving target is associated with only one N d , but multiple spectrum segments are associated with multiple N s 's. The ASA issue has been tackled in [1,2]. In [1], a deramp space-time adaptive process (STAP) was applied on a multi-channel SAR system, composed of one transmitter and an array of receivers, to tackle the ASA issue and coarsely focus the ground moving targets (GMTs) in a Doppler frequency-angle domain.…”

Section: Introductionmentioning

confidence: 99%

Multi-Channel SAR Imaging on Cruising Ships with Sub-Orbital Spaceplane

Kiang

2022

Remote Sensing

View full text Add to dashboard Cite

A multi-channel synthetic aperture radar (SAR) on board a spaceplane orbiting near the top of the atmosphere is proposed to acquire images of cruising ships. Low pulse repetition frequency (PRF) is required for high-resolution wide-swath (HRWS) imaging, leading to inevitable problems of azimuth spectrum aliasing (ASA) and azimuth Doppler ambiguity (ADA). In this work, we propose a phase matching technique to solve the ASA problem in restoring the azimuth spectrum. A multi-stage compressive-sensing (CS) technique is also proposed to solve both ADA and ASA problems. Five similar types of cruising ship are simulated to verify the efficacy of the proposed approach, at different levels of signal-to-noise ratio. Indices of geometry match, intensity match, and structural similarity are used to identify different ships from the acquired SAR images.

show abstract

A Novel Azimuth Spectrum Reconstruction and Imaging Method for Moving Targets in Geosynchronous Spaceborne–Airborne Bistatic Multichannel SAR

Cited by 25 publications

References 54 publications

SAR Imaging Method for Moving Target With Azimuth Missing Data

SAR Imaging Method for Moving Target With Azimuth Missing Data

A Novel Frequency-Domain Focusing Method for Geosynchronous Low-Earth-Orbit Bistatic SAR in Sliding-Spotlight Mode

Multi-Channel SAR Imaging on Cruising Ships with Sub-Orbital Spaceplane

Contact Info

Product

Resources

About