High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRF
Synthetic Aperture Radar (SAR) is a well-established and powerful imaging technique for acquiring high-spatial-resolution images of the Earth’s surface. With the development of beam steering techniques, sliding spotlight and staring spotlight modes have been employed to support high-spatial-resoluti...
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| Format: | Article |
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MDPI AG
2017-07-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/17/8/1700 |
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| author | Zhirong Men Pengbo Wang Chunsheng Li Jie Chen Wei Liu Yue Fang |
| author_facet | Zhirong Men Pengbo Wang Chunsheng Li Jie Chen Wei Liu Yue Fang |
| author_sort | Zhirong Men |
| collection | DOAJ |
| description | Synthetic Aperture Radar (SAR) is a well-established and powerful imaging technique for acquiring high-spatial-resolution images of the Earth’s surface. With the development of beam steering techniques, sliding spotlight and staring spotlight modes have been employed to support high-spatial-resolution applications. In addition to this strengthened high-spatial-resolution and wide-swath capability, high-temporal-resolution (short repeat-observation interval) represents a key capability for numerous applications. However, conventional SAR systems are limited in that the same patch can only be illuminated for several seconds within a single pass. This paper considers a novel high-squint-angle system intended to acquire high-spatial-resolution spaceborne SAR images with repeat-observation intervals varying from tens of seconds to several minutes within a single pass. However, an exponentially increased range cell migration would arise and lead to a conflict between the receive window and ‘blind ranges’. An efficient data acquisition technique for high-temporal-resolution, high-spatial-resolution and high-squint-angle spaceborne SAR, in which the pulse repetition frequency (PRF) is continuously varied according to the changing slant range, is presented in this paper. This technique allows echo data to remain in the receive window instead of conflicting with the transmitted pulse or nadir echo. Considering the precision of hardware, a compromise and practical strategy is also proposed. Furthermore, a detailed performance analysis of range ambiguities is provided with respect to parameters of TerraSAR-X. For strong point-like targets, the range ambiguity of this technique would be better than that of uniform PRF technique. For this innovative technique, a resampling strategy and modified imaging algorithm have been developed to handle the non-uniformly sampled echo data. Simulations are performed to validate the efficiency of the proposed technique and the associated imaging algorithm. |
| first_indexed | 2024-12-10T07:16:52Z |
| format | Article |
| id | doaj.art-8f6ca51d04dd485fba00438e788aaa1e |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-12-10T07:16:52Z |
| publishDate | 2017-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-8f6ca51d04dd485fba00438e788aaa1e2022-12-22T01:57:54ZengMDPI AGSensors1424-82202017-07-01178170010.3390/s17081700s17081700High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRFZhirong Men0Pengbo Wang1Chunsheng Li2Jie Chen3Wei Liu4Yue Fang5School of Electronic and Information Engineering, Beihang University, Beijing 100191, ChinaSchool of Electronic and Information Engineering, Beihang University, Beijing 100191, ChinaSchool of Electronic and Information Engineering, Beihang University, Beijing 100191, ChinaSchool of Electronic and Information Engineering, Beihang University, Beijing 100191, ChinaElectronic and Electronic Engineering Department, University of Sheffield, Sheffield S1-3JD, UKSchool of Electronic and Information Engineering, Beihang University, Beijing 100191, ChinaSynthetic Aperture Radar (SAR) is a well-established and powerful imaging technique for acquiring high-spatial-resolution images of the Earth’s surface. With the development of beam steering techniques, sliding spotlight and staring spotlight modes have been employed to support high-spatial-resolution applications. In addition to this strengthened high-spatial-resolution and wide-swath capability, high-temporal-resolution (short repeat-observation interval) represents a key capability for numerous applications. However, conventional SAR systems are limited in that the same patch can only be illuminated for several seconds within a single pass. This paper considers a novel high-squint-angle system intended to acquire high-spatial-resolution spaceborne SAR images with repeat-observation intervals varying from tens of seconds to several minutes within a single pass. However, an exponentially increased range cell migration would arise and lead to a conflict between the receive window and ‘blind ranges’. An efficient data acquisition technique for high-temporal-resolution, high-spatial-resolution and high-squint-angle spaceborne SAR, in which the pulse repetition frequency (PRF) is continuously varied according to the changing slant range, is presented in this paper. This technique allows echo data to remain in the receive window instead of conflicting with the transmitted pulse or nadir echo. Considering the precision of hardware, a compromise and practical strategy is also proposed. Furthermore, a detailed performance analysis of range ambiguities is provided with respect to parameters of TerraSAR-X. For strong point-like targets, the range ambiguity of this technique would be better than that of uniform PRF technique. For this innovative technique, a resampling strategy and modified imaging algorithm have been developed to handle the non-uniformly sampled echo data. Simulations are performed to validate the efficiency of the proposed technique and the associated imaging algorithm.https://www.mdpi.com/1424-8220/17/8/1700high-temporal-resolutionhigh-spatial-resolutionhigh-squint-anglesynthetic aperture radar (SAR)continuously varying PRF (CVPRF)high-order imaging algorithm |
| spellingShingle | Zhirong Men Pengbo Wang Chunsheng Li Jie Chen Wei Liu Yue Fang High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRF Sensors high-temporal-resolution high-spatial-resolution high-squint-angle synthetic aperture radar (SAR) continuously varying PRF (CVPRF) high-order imaging algorithm |
| title | High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRF |
| title_full | High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRF |
| title_fullStr | High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRF |
| title_full_unstemmed | High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRF |
| title_short | High-Temporal-Resolution High-Spatial-Resolution Spaceborne SAR Based on Continuously Varying PRF |
| title_sort | high temporal resolution high spatial resolution spaceborne sar based on continuously varying prf |
| topic | high-temporal-resolution high-spatial-resolution high-squint-angle synthetic aperture radar (SAR) continuously varying PRF (CVPRF) high-order imaging algorithm |
| url | https://www.mdpi.com/1424-8220/17/8/1700 |
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