An Accelerated Backprojection Algorithm for Monostatic and Bistatic SAR Processing
The backprojection (BP) algorithm has been applied to every SAR mode due to its great focusing quality and adaptability. However, the BP algorithm suffers from immense computational complexity. To improve the efficiency of the conventional BP algorithm, several fast BP (FBP) algorithms, such as the...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2018-01-01
|
| Series: | Remote Sensing |
| Subjects: | |
| Online Access: | http://www.mdpi.com/2072-4292/10/1/140 |
| _version_ | 1819002997228699648 |
|---|---|
| author | Heng Zhang Jiangwen Tang Robert Wang Yunkai Deng Wei Wang Ning Li |
| author_facet | Heng Zhang Jiangwen Tang Robert Wang Yunkai Deng Wei Wang Ning Li |
| author_sort | Heng Zhang |
| collection | DOAJ |
| description | The backprojection (BP) algorithm has been applied to every SAR mode due to its great focusing quality and adaptability. However, the BP algorithm suffers from immense computational complexity. To improve the efficiency of the conventional BP algorithm, several fast BP (FBP) algorithms, such as the fast factorization BP (FFBP) and Block_FFBP, have been developed in recent studies. In the derivation of Block_FFBP, range data are divided into blocks, and the upsampling process is performed using an interpolation kernel instead of a fast Fourier transform (FFT), which reduces the processing efficiency. To circumvent these limitations, an accelerated BP algorithm based on Block_FFBP is proposed. In this algorithm, a fixed number of pivots rather than the beam centers is applied to construct the relationship of the propagation time delay between the “new” and “old” subapertures. Partition in the range dimension is avoided, and the range data are processed as a bulk. This accelerated BP algorithm benefits from the integrated range processing scheme and is extended to bistatic SAR processing. In this sense, the proposed algorithm can be referred to simply as MoBulk_FFBP for the monostatic SAR case and BiBulk_FFBP for the bistatic SAR case. Furthermore, for monostatic and azimuth-invariant bistatic SAR cases where the platform runs along a straight trajectory, the slant range mapping can be expressed in a continuous and analytical form. Real data from the spaceborne/stationary bistatic SAR experiment with TerraSAR-X operating in the staring spotlight mode and from the airborne spotlight SAR experiment acquired in 2016 are used to validate the performances of BiBulk_FFBP and MoBulk_FFBP, respectively. |
| first_indexed | 2024-12-20T23:13:59Z |
| format | Article |
| id | doaj.art-e9dfc4e3e4394bd89228c0995248d948 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-12-20T23:13:59Z |
| publishDate | 2018-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-e9dfc4e3e4394bd89228c0995248d9482022-12-21T19:23:41ZengMDPI AGRemote Sensing2072-42922018-01-0110114010.3390/rs10010140rs10010140An Accelerated Backprojection Algorithm for Monostatic and Bistatic SAR ProcessingHeng Zhang0Jiangwen Tang1Robert Wang2Yunkai Deng3Wei Wang4Ning Li5Department of Space Microwave Remote Sensing Systems, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, ChinaDepartment of Space Microwave Remote Sensing Systems, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, ChinaDepartment of Space Microwave Remote Sensing Systems, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, ChinaDepartment of Space Microwave Remote Sensing Systems, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, ChinaDepartment of Space Microwave Remote Sensing Systems, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, ChinaDepartment of Space Microwave Remote Sensing Systems, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, ChinaThe backprojection (BP) algorithm has been applied to every SAR mode due to its great focusing quality and adaptability. However, the BP algorithm suffers from immense computational complexity. To improve the efficiency of the conventional BP algorithm, several fast BP (FBP) algorithms, such as the fast factorization BP (FFBP) and Block_FFBP, have been developed in recent studies. In the derivation of Block_FFBP, range data are divided into blocks, and the upsampling process is performed using an interpolation kernel instead of a fast Fourier transform (FFT), which reduces the processing efficiency. To circumvent these limitations, an accelerated BP algorithm based on Block_FFBP is proposed. In this algorithm, a fixed number of pivots rather than the beam centers is applied to construct the relationship of the propagation time delay between the “new” and “old” subapertures. Partition in the range dimension is avoided, and the range data are processed as a bulk. This accelerated BP algorithm benefits from the integrated range processing scheme and is extended to bistatic SAR processing. In this sense, the proposed algorithm can be referred to simply as MoBulk_FFBP for the monostatic SAR case and BiBulk_FFBP for the bistatic SAR case. Furthermore, for monostatic and azimuth-invariant bistatic SAR cases where the platform runs along a straight trajectory, the slant range mapping can be expressed in a continuous and analytical form. Real data from the spaceborne/stationary bistatic SAR experiment with TerraSAR-X operating in the staring spotlight mode and from the airborne spotlight SAR experiment acquired in 2016 are used to validate the performances of BiBulk_FFBP and MoBulk_FFBP, respectively.http://www.mdpi.com/2072-4292/10/1/140accelerated backprojection algorithmbistatic SARmonostatic SARbulk processing |
| spellingShingle | Heng Zhang Jiangwen Tang Robert Wang Yunkai Deng Wei Wang Ning Li An Accelerated Backprojection Algorithm for Monostatic and Bistatic SAR Processing Remote Sensing accelerated backprojection algorithm bistatic SAR monostatic SAR bulk processing |
| title | An Accelerated Backprojection Algorithm for Monostatic and Bistatic SAR Processing |
| title_full | An Accelerated Backprojection Algorithm for Monostatic and Bistatic SAR Processing |
| title_fullStr | An Accelerated Backprojection Algorithm for Monostatic and Bistatic SAR Processing |
| title_full_unstemmed | An Accelerated Backprojection Algorithm for Monostatic and Bistatic SAR Processing |
| title_short | An Accelerated Backprojection Algorithm for Monostatic and Bistatic SAR Processing |
| title_sort | accelerated backprojection algorithm for monostatic and bistatic sar processing |
| topic | accelerated backprojection algorithm bistatic SAR monostatic SAR bulk processing |
| url | http://www.mdpi.com/2072-4292/10/1/140 |
| work_keys_str_mv | AT hengzhang anacceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT jiangwentang anacceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT robertwang anacceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT yunkaideng anacceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT weiwang anacceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT ningli anacceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT hengzhang acceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT jiangwentang acceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT robertwang acceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT yunkaideng acceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT weiwang acceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing AT ningli acceleratedbackprojectionalgorithmformonostaticandbistaticsarprocessing |