Highly Squinted MEO SAR Focusing Based on Extended Omega-K Algorithm and Modified Joint Time and Doppler Resampling

Wenkang Liu; Guang Cai Sun; Xiang Gen Xia; Dong You; Mengdao Xing; Zheng Bao

doi:10.1109/TGRS.2019.2925385

Highly Squinted MEO SAR Focusing Based on Extended Omega-K Algorithm and Modified Joint Time and Doppler Resampling

Wenkang Liu, Guang Cai Sun^*, Xiang Gen Xia, Dong You, Mengdao Xing, Zheng Bao

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

23 Citations (Scopus)

Abstract

A squinted observation geometry along with long integration time significantly aggravates the range walk and spatial variation of a medium-earth-orbit (MEO) synthetic aperture radar (SAR) signal. Variable pulse repeating frequency (PRF) is recommended to avoid the blockage in echo recording and save storage space. The existing wavenumber algorithms cannot handle the nonlinear and range-azimuth-coupled spatial variation (RACSP) over a large scene. In this paper, we propose a modified Stolt mapping method along with a modified joint time and Doppler resampling (JTDR) for highly squinted MEO SAR data processing. An azimuth timescale transformation is used to deal with the nonlinear spatial variation of the azimuth frequency-modulation (FM) rate. An extended Omega-K is used to linearize the range frequency and achieve range cell migration correction (RCMC). To address the RACSP, the Doppler is linearized in the range-Doppler domain using a range-dependent Doppler scale transformation. The computational complexity and geometry distortion correction (GDC) are also discussed. Simulation results are shown to verify the effectiveness of the developed focusing approaches.

Original language	English
Article number	8793224
Pages (from-to)	9188-9200
Number of pages	13
Journal	IEEE Transactions on Geoscience and Remote Sensing
Volume	57
Issue number	11
DOIs	https://doi.org/10.1109/TGRS.2019.2925385
Publication status	Published - Nov 2019
Externally published	Yes

Keywords

Highly squinted 2-D spatial variation
Omega-K
joint time and Doppler resampling (JTDR)
medium-earth-orbit synthetic aperture radar (MEO SAR)

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10.1109/TGRS.2019.2925385

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title = "Highly Squinted MEO SAR Focusing Based on Extended Omega-K Algorithm and Modified Joint Time and Doppler Resampling",

abstract = "A squinted observation geometry along with long integration time significantly aggravates the range walk and spatial variation of a medium-earth-orbit (MEO) synthetic aperture radar (SAR) signal. Variable pulse repeating frequency (PRF) is recommended to avoid the blockage in echo recording and save storage space. The existing wavenumber algorithms cannot handle the nonlinear and range-azimuth-coupled spatial variation (RACSP) over a large scene. In this paper, we propose a modified Stolt mapping method along with a modified joint time and Doppler resampling (JTDR) for highly squinted MEO SAR data processing. An azimuth timescale transformation is used to deal with the nonlinear spatial variation of the azimuth frequency-modulation (FM) rate. An extended Omega-K is used to linearize the range frequency and achieve range cell migration correction (RCMC). To address the RACSP, the Doppler is linearized in the range-Doppler domain using a range-dependent Doppler scale transformation. The computational complexity and geometry distortion correction (GDC) are also discussed. Simulation results are shown to verify the effectiveness of the developed focusing approaches.",

keywords = "Highly squinted 2-D spatial variation, Omega-K, joint time and Doppler resampling (JTDR), medium-earth-orbit synthetic aperture radar (MEO SAR)",

author = "Wenkang Liu and Sun, {Guang Cai} and Xia, {Xiang Gen} and Dong You and Mengdao Xing and Zheng Bao",

note = "Publisher Copyright: {\textcopyright} 2019 IEEE.",

year = "2019",

month = nov,

doi = "10.1109/TGRS.2019.2925385",

language = "English",

volume = "57",

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T1 - Highly Squinted MEO SAR Focusing Based on Extended Omega-K Algorithm and Modified Joint Time and Doppler Resampling

AU - Liu, Wenkang

AU - Sun, Guang Cai

AU - Xia, Xiang Gen

AU - You, Dong

AU - Xing, Mengdao

AU - Bao, Zheng

PY - 2019/11

Y1 - 2019/11

N2 - A squinted observation geometry along with long integration time significantly aggravates the range walk and spatial variation of a medium-earth-orbit (MEO) synthetic aperture radar (SAR) signal. Variable pulse repeating frequency (PRF) is recommended to avoid the blockage in echo recording and save storage space. The existing wavenumber algorithms cannot handle the nonlinear and range-azimuth-coupled spatial variation (RACSP) over a large scene. In this paper, we propose a modified Stolt mapping method along with a modified joint time and Doppler resampling (JTDR) for highly squinted MEO SAR data processing. An azimuth timescale transformation is used to deal with the nonlinear spatial variation of the azimuth frequency-modulation (FM) rate. An extended Omega-K is used to linearize the range frequency and achieve range cell migration correction (RCMC). To address the RACSP, the Doppler is linearized in the range-Doppler domain using a range-dependent Doppler scale transformation. The computational complexity and geometry distortion correction (GDC) are also discussed. Simulation results are shown to verify the effectiveness of the developed focusing approaches.

AB - A squinted observation geometry along with long integration time significantly aggravates the range walk and spatial variation of a medium-earth-orbit (MEO) synthetic aperture radar (SAR) signal. Variable pulse repeating frequency (PRF) is recommended to avoid the blockage in echo recording and save storage space. The existing wavenumber algorithms cannot handle the nonlinear and range-azimuth-coupled spatial variation (RACSP) over a large scene. In this paper, we propose a modified Stolt mapping method along with a modified joint time and Doppler resampling (JTDR) for highly squinted MEO SAR data processing. An azimuth timescale transformation is used to deal with the nonlinear spatial variation of the azimuth frequency-modulation (FM) rate. An extended Omega-K is used to linearize the range frequency and achieve range cell migration correction (RCMC). To address the RACSP, the Doppler is linearized in the range-Doppler domain using a range-dependent Doppler scale transformation. The computational complexity and geometry distortion correction (GDC) are also discussed. Simulation results are shown to verify the effectiveness of the developed focusing approaches.

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ER -

Highly Squinted MEO SAR Focusing Based on Extended Omega-K Algorithm and Modified Joint Time and Doppler Resampling

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Keywords

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