Range-Variant Channel Errors Calibration Algorithm for Multichannel HRWS SAR Imaging

Zhang, Tianjian; Qiu, Xiaoyan; Xu, Yanzhang; Tang, Zhenhua; Tian, Yuan

doi:10.1109/sars.2018.8552024

Cited by 3 publications

(2 citation statements)

References 11 publications

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“…To maximize the sharpness of the reconstructed Doppler spectrum, one can take advantage of the sharpness optimization technique for phase calibration. The phase error parameters yield the highest level of sharpness optimization and is given by the following: κ, δ = arg max F(κ, δ) (23) The sharpness optimization is generally convex within a local range, without any constraint. It is important to note that additional metric functions can be used to characterize the intensity distribution feature of the reconstructed Doppler spectrum.…”

Section: Range-dependent Calibration With the Maximum Sharpness Optim...mentioning

confidence: 99%

“…It is generally acceptable to simplify the time-variant imbalance in a constant model during a system operation period. However, in real HRWS SAR systems [ 23 , 24 , 25 ], there may be spatially dependent channel imbalance. The antenna pattern can be significantly inconsistent in both phase and amplitude, especially when some channels gradually degrade over time.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Range-Dependent Channel Calibration for High-Resolution Wide-Swath Synthetic Aperture Radar Imagery

Zhang,

Meng,

Wang

et al. 2024

Sensors

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High-resolution and wide-swath (HRWS) synthetic aperture radar (SAR) imaging with azimuth multi-channel always suffers from channel phase and amplitude errors. Compared with spatial-invariant error, the range-dependent channel phase error is intractable due to its spatial dependency characteristic. This paper proposes a novel parameterized channel equalization approach to reconstruct the unambiguous SAR imagery. First, a linear model is established for the range-dependent channel phase error, and the sharpness of the reconstructed Doppler spectrum is used to measure the unambiguity quality. Furthermore, the intrinsic relationship between the channel phase errors and the sharpness is revealed, which allows us to estimate the optimal parameters by maximizing the sharpness of the reconstructed Doppler spectrum. Finally, the results from real-measured data show that the suggested method performs exceptionally for ambiguity suppression in HRWS SAR imaging.

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Section: Range-dependent Calibration With the Maximum Sharpness Optim...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Range-Dependent Channel Calibration for High-Resolution Wide-Swath Synthetic Aperture Radar Imagery

Zhang,

Meng,

Wang

et al. 2024

Sensors

View full text Add to dashboard Cite

show abstract

A two-step channel mismatch estimation and compensation method for distributed MC SAR

Zhang

Ding

Dong

2021

International Journal of Remote Sensing

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Elevation Multi-Channel Imbalance Calibration Method of Digital Beamforming Synthetic Aperture Radar

Chen

Ming

et al. 2022

Remote Sensing

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The digital beamforming synthetic aperture radar (DBF-SAR) is proposed by scholars as a promising solution to overcome the constraint of the minimum antenna area of the traditional single-channel SAR to achieve high resolution and wide swath (HRWS) by scan-on-receive (SCORE) in the elevation multiple channel. However, the inevitable channel imbalance between the elevation channels of DBF-SAR will degrade the DBF-SAR image quality. In this paper, we present a method to estimate the sampling time delay error, amplitude error and phase error based on the external calibration data. For the sampling time delay deviation, we adopt to calculate the statistical average of the position deviation of several external calibration points in the reference channel image with that of the error channel image. To avoid noise interference, we image the DBF-SAR original echo-carrying amplitude information to obtain the amplitude error between channels by dividing the absolute values of the complex image data of the error channel. Due to the phase error between channels, the image contrast will decrease. Therefore, the problem of estimating the phase error can be transformed into the problem of maximizing the image contrast. So, in this paper, we use the gradient descent method to optimally estimate the phase error. Finally, the effectiveness of the method is verified by the simulation of airborne measured data and simulation data.

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Range-Variant Channel Errors Calibration Algorithm for Multichannel HRWS SAR Imaging

Cited by 3 publications

References 11 publications

Range-Dependent Channel Calibration for High-Resolution Wide-Swath Synthetic Aperture Radar Imagery

Range-Dependent Channel Calibration for High-Resolution Wide-Swath Synthetic Aperture Radar Imagery

A two-step channel mismatch estimation and compensation method for distributed MC SAR

Elevation Multi-Channel Imbalance Calibration Method of Digital Beamforming Synthetic Aperture Radar

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