Two-Dimensional Autofocus Combined With the TSA for Spotlight SAR
For high-resolution spotlight synthetic aperture radar, Doppler aliasing is always introduced in the long synthetic aperture observation time. The existence of signal Doppler aliasing will greatly affect the accuracy of motion compensation. To avoid Doppler aliasing, it is an effective strategy to u...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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IEEE
2023-01-01
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| Series: | IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/10266692/ |
| _version_ | 1797635459906535424 |
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| author | Hao Lin Xiaoyu Xue Ning Li Mengdao Xing |
| author_facet | Hao Lin Xiaoyu Xue Ning Li Mengdao Xing |
| author_sort | Hao Lin |
| collection | DOAJ |
| description | For high-resolution spotlight synthetic aperture radar, Doppler aliasing is always introduced in the long synthetic aperture observation time. The existence of signal Doppler aliasing will greatly affect the accuracy of motion compensation. To avoid Doppler aliasing, it is an effective strategy to use the subaperture (SA) approach. However, it will introduce the long synthetic aperture time stitching problem of signal and phase error. Compared with the SA approach, the two-step approach (TSA) based on the full aperture not only eliminates the Doppler aliasing but also avoids the signal splicing problem. Therefore, a two-dimensional (2-D) frequency-domain autofocus combined with the TSA is adopted in this article. First, TSA is used to perform dealiasing and coarse focusing imaging on full-aperture (FA) data. Second, the phase error history and the phase error form in the TSA process are analyzed and deduced, and an accurate prior structure of the phase errors is established. Then, the accurate inversion of the common 2-D phase errors is realized based on this prior structure. Finally, the autofocus process of the FA signal combined with the TSA is realized in the nonaliasing 2-D frequency domain. The validity of the recommended algorithm is verified by simulation and experimental results. |
| first_indexed | 2024-03-11T12:22:18Z |
| format | Article |
| id | doaj.art-f0dea1e0915f4ed1a027d4900471b041 |
| institution | Directory Open Access Journal |
| issn | 2151-1535 |
| language | English |
| last_indexed | 2024-03-11T12:22:18Z |
| publishDate | 2023-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing |
| spelling | doaj.art-f0dea1e0915f4ed1a027d4900471b0412023-11-07T00:00:42ZengIEEEIEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing2151-15352023-01-01169563957310.1109/JSTARS.2023.332055510266692Two-Dimensional Autofocus Combined With the TSA for Spotlight SARHao Lin0https://orcid.org/0009-0002-1533-791XXiaoyu Xue1https://orcid.org/0009-0008-1563-386XNing Li2https://orcid.org/0000-0003-3389-981XMengdao Xing3https://orcid.org/0000-0002-4084-0915National Key Laboratory of Radar Signal Processing and the Collaborative Innovation Center of Information Sensing and Understanding, Xidian University, Xi'an, ChinaNational Key Laboratory of Radar Signal Processing and the Collaborative Innovation Center of Information Sensing and Understanding, Xidian University, Xi'an, ChinaAcademy of Advanced Interdisciplinary Research, Xidian University, Xi'an, ChinaNational Key Laboratory of Radar Signal Processing, the Collaborative Innovation Center of Information Sensing and Understanding, and the Academy of Advanced Interdisciplinary Research, Xidian University, Xi'an, ChinaFor high-resolution spotlight synthetic aperture radar, Doppler aliasing is always introduced in the long synthetic aperture observation time. The existence of signal Doppler aliasing will greatly affect the accuracy of motion compensation. To avoid Doppler aliasing, it is an effective strategy to use the subaperture (SA) approach. However, it will introduce the long synthetic aperture time stitching problem of signal and phase error. Compared with the SA approach, the two-step approach (TSA) based on the full aperture not only eliminates the Doppler aliasing but also avoids the signal splicing problem. Therefore, a two-dimensional (2-D) frequency-domain autofocus combined with the TSA is adopted in this article. First, TSA is used to perform dealiasing and coarse focusing imaging on full-aperture (FA) data. Second, the phase error history and the phase error form in the TSA process are analyzed and deduced, and an accurate prior structure of the phase errors is established. Then, the accurate inversion of the common 2-D phase errors is realized based on this prior structure. Finally, the autofocus process of the FA signal combined with the TSA is realized in the nonaliasing 2-D frequency domain. The validity of the recommended algorithm is verified by simulation and experimental results.https://ieeexplore.ieee.org/document/10266692/2-D autofocus processmotion compensation (MoCo)synthetic aperture radar (SAR)two-step approach (TSA) |
| spellingShingle | Hao Lin Xiaoyu Xue Ning Li Mengdao Xing Two-Dimensional Autofocus Combined With the TSA for Spotlight SAR IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 2-D autofocus process motion compensation (MoCo) synthetic aperture radar (SAR) two-step approach (TSA) |
| title | Two-Dimensional Autofocus Combined With the TSA for Spotlight SAR |
| title_full | Two-Dimensional Autofocus Combined With the TSA for Spotlight SAR |
| title_fullStr | Two-Dimensional Autofocus Combined With the TSA for Spotlight SAR |
| title_full_unstemmed | Two-Dimensional Autofocus Combined With the TSA for Spotlight SAR |
| title_short | Two-Dimensional Autofocus Combined With the TSA for Spotlight SAR |
| title_sort | two dimensional autofocus combined with the tsa for spotlight sar |
| topic | 2-D autofocus process motion compensation (MoCo) synthetic aperture radar (SAR) two-step approach (TSA) |
| url | https://ieeexplore.ieee.org/document/10266692/ |
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