基于多项式模型和方位重采样的中高轨斜视滑动聚束SAR成像方法
收稿日期: 2024-01-03
修回日期: 2024-03-26
网络出版日期: 2024-04-07
基金资助
电子学会第六届青托(E2H2160202)
Imaging algorithm for squint sliding spotlight SAR operating in medium-earth-orbit based on polynomial and azimuth resampling method
Received date: 2024-01-03
Revised date: 2024-03-26
Online published: 2024-04-07
中高轨道合成孔径雷达（MEO SAR）具备短重访周期、高空间分辨率和宽测绘带宽的能力，在军民领域都有良好应用前景。MEO SAR通过滑动聚束模式提高方位分辨率，并通过斜视的工作模式提升系统灵活性。然而，轨道高度的提高使得方位平移不变假设不再成立，斜视滑聚工作模式也会导致频谱扭曲。对此，基于多项式信号模型建模方法，推导成像参数的计算过程。通过引入一种新的模型拟合方法和去斜函数，将只适用于条带模式的方位时域重采样方法推广到滑动聚束模式下，用于校正方位空变性。提出非线性平移法结合两步式的处理流程，解决斜视滑聚模式下的频谱混叠问题。最后通过仿真实验进行验证。
郭艺琼 , 任明山 , 张衡 , 岳海霞 . 基于多项式模型和方位重采样的中高轨斜视滑动聚束SAR成像方法[J]. 中国科学院大学学报, 2026 , 43(1) : 61 -69 . DOI: 10.7523/j.ucas.2024.009
The medium-earth-orbit synthetic aperture radar （MEO SAR） possesses the capability of short revisit period， high spatial resolution， and wide coverage， which has promising applications in both military and civilian fields. The MEO SAR can improve azimuth resolution by operating in sliding spotlight mode， and can enhance system flexibility through squint imaging mode. However， the increase in orbit height invalidates the assumption of azimuth invariance and the squint mode causes spectrum distortion. In this paper， first， we derive the calculation process of imaging parameters based on the polynomial signal model. Then， by introducing a new model fitting method and a deramp function， we extend the azimuth time-domain resampling method from the stripmap mode to the sliding spotlight mode， correcting the azimuth space-variant characteristics. We further propose a processing flow by combining the two-step method and the non-linear range walk correction to solve the spectrum aliasing in the squint sliding spotlight mode. Finally， the proposed method is verified through simulation experiments.
| [1] | 黄丽佳. 中高轨道SAR成像算法研究［D］. 北京： 中国科学院研究生院， 2011. |
| [2] | 刘文康. 中高轨合成孔径雷达成像关键技术研究［D］. 西安： 西安电子科技大学， 2020. |
| [3] | Matar J， Rodriguez-Cassola M， Krieger G， et al. MEO SAR： system concepts and analysis［J］. IEEE Transactions on Geoscience and Remote Sensing， 2020， 58（2）： 1313-1324. DOI： 10.1109/TGRS.2019.2945875 . |
| [4] | Matar J， Rodriguez-Cassola M. Mission considerations for future MEO SAR systems［C］//EUSAR 2018， 12th European Conference on Synthetic Aperture Radar. Aachen， Germany. VDE， 2018：1-5. |
| [5] | Cumming I G， Wong F H C. Digital processing of synthetic aperture radar data： algorithms and implementation［M］. Boston： Artech House， 2005. |
| [6] | Huang L J， Qiu X L， Hu D H， et al. Focusing of medium-earth-orbit SAR with advanced nonlinear chirp scaling algorithm［J］. IEEE Transactions on Geoscience and Remote Sensing， 2011， 49（1）： 500-508. DOI： 10.1109/TGRS.2010.2053211 . |
| [7] | Wang P B， Liu W， Chen J， et al. A high-order imaging algorithm for high-resolution spaceborne SAR based on a modified equivalent squint range model［J］. IEEE Transactions on Geoscience and Remote Sensing， 2015， 53（3）： 1225-1235. DOI： 10.1109/TGRS.2014.2336241 . |
| [8] | Wu Y， Sun G C， Yang C， et al. Processing of very high resolution spaceborne sliding spotlight SAR data using velocity scaling［J］. IEEE Transactions on Geoscience and Remote Sensing， 2016， 54（3）： 1505-1518. DOI： 10.1109/TGRS.2015.2481923 . |
| [9] | Sun G C， Wu Y， Yang J， et al. Full-aperture focusing of very high resolution spaceborne-squinted sliding spotlight SAR data［J］. IEEE Transactions on Geoscience and Remote Sensing， 2017， 55（6）： 3309-3321. DOI： 10.1109/TGRS.2017.2669205 . |
| [10] | Ding Z G， Zheng P N， Li H， et al. Spaceborne high-squint high-resolution SAR imaging based on two-dimensional spatial-variant range cell migration correction［J］. IEEE Transactions on Geoscience and Remote Sensing， 2022， 60： 5240114. DOI： 10.1109/TGRS.2022.3222230 . |
| [11] | Zhao B J， Qi X Y， Song H J， et al. An accurate range model based on the fourth-order Doppler parameters for geosynchronous SAR［J］. IEEE Geoscience and Remote Sensing Letters， 2014， 11（1）： 205-209. DOI： 10.1109/LGRS.2013.2252878 . |
| [12] | Liu W K， Sun G C， Xia X G， et al. A modified CSA based on joint time-Doppler resampling for MEO SAR stripmap mode［J］. IEEE Transactions on Geoscience and Remote Sensing， 2018， 56（6）： 3573-3586. DOI： 10.1109/TGRS.2018.2802545 . |
| [13] | Liu W K， Sun G C， Xia X G， et al. Highly squinted MEO SAR focusing based on extended omega-K algorithm and modified joint time and Doppler resampling［J］. IEEE Transactions on Geoscience and Remote Sensing， 2019， 57（11）： 9188-9200. DOI： 10.1109/TGRS.2019.2925385 . |
| [14] | Huang L J， Qiu X L， Hu D H， et al. Medium-earth-orbit SAR focusing using range Doppler algorithm with integrated two-step azimuth perturbation［J］. IEEE Geoscience and Remote Sensing Letters， 2015， 12（3）： 626-630. DOI： 10.1109/LGRS.2014.2353674 . |
| [15] | D’Aria D， Monti Guarnieri A. High-resolution spaceborne SAR focusing by SVD-stolt［J］. IEEE Geoscience and Remote Sensing Letters， 2007， 4（4）： 639-643. DOI： 10.1109/LGRS.2007.903081 . |
| [16] | Chen J L， Sun G C， Wang Y， et al. A TSVD-NCS algorithm in range-doppler domain for geosynchronous synthetic aperture radar［J］. IEEE Geoscience and Remote Sensing Letters， 2016， 13（11）： 1631-1635. DOI： 10.1109/LGRS.2016.2599224 . |
| [17] | 谈璐璐， 盛磊. 中轨SAR系统设计及关键技术研究［J］.雷达科学与技术， 2017， 15（2）： 148-152， 158. DOI：10.3969/j.issn.1672-2337.2017.02.007 . |
| [18] | Mittermayer J， Moreira A， Loffeld O. Spotlight SAR data processing using the frequency scaling algorithm［J］. IEEE Transactions on Geoscience and Remote Sensing， 1999， 37（5）： 2198-2214. DOI： 10.1109/36.789617 . |
| [19] | Prats P， Scheiber R， Mittermayer J， et al. Processing of sliding spotlight and TOPS SAR data using baseband azimuth scaling［J］. IEEE Transactions on Geoscience and Remote Sensing， 2010， 48（2）： 770-780. DOI： 10.1109/TGRS.2009.2027701 . |
| [20] | Moreira A， Mittermayer J， Scheiber R. Extended chirp scaling algorithm for air-and spaceborne SAR data processing in stripmap and ScanSAR imaging modes［J］. IEEE Transactions on Geoscience and Remote Sensing， 1996， 34（5）： 1123-1136. DOI：10.1109/36.536528 . |
| [21] | Lanari R， Zoffoli S， Sansosti E， et al. New approach for hybrid strip-map∕spotlight SAR data focusing［J］. IEE Proceedings - Radar， Sonar and Navigation， 2001， 148（6）： 363-372. DOI： 10.1049/ip-rsn：20010662 . |
| [22] | Lanari R， Tesauro M， Sansosti E， et al. Spotlight SAR data focusing based on a two-step processing approach［J］. IEEE Transactions on Geoscience and Remote Sensing， 2001， 39（9）： 1993-2004. DOI：10.1109/36.951090 . |
| [23] | 安道祥. 高分辨率SAR成像处理技术研究［D］. 长沙： 国防科学技术大学， 2011. |
| [24] | Xing M D， Wu Y F， Zhang Y D， et al. Azimuth resampling processing for highly squinted synthetic aperture radar imaging with several modes［J］. IEEE Transactions on Geoscience and Remote Sensing， 2014， 52（7）： 4339-4352. DOI： 10.1109/TGRS.2013.2281454 . |
/
| 〈 |
|
〉 |
