一種基于極坐標(biāo)格式算法的高分辨SAR成像自聚焦算法
doi: 10.11999/JEIT141131
基金項(xiàng)目:
中央高?；究蒲袠I(yè)務(wù)費(fèi)專(zhuān)項(xiàng)資金(K5051302046)和國(guó)家自然科學(xué)基金優(yōu)秀青年基金(61222108)資助課題
Autofocus Algorithm of High Resolution SAR Based on Polar Format Algorithm Processing
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摘要: 針對(duì)機(jī)載聚束合成孔徑雷達(dá)(SAR)慣導(dǎo)精度無(wú)法滿(mǎn)足高分辨SAR成像的問(wèn)題，該文提出了一種結(jié)合極坐標(biāo)格式算法(PFA)的自聚焦算法，即由粗到精的混合多階段參數(shù)化最小熵(Hybrid Multistage Parameterized Minimum Entropy, HMPME)距離單元徙動(dòng)校正方法和基于圖像對(duì)比度增強(qiáng)(Contrast Enhancement, CE)的變步長(zhǎng)迭代相位誤差校正方法。該自聚焦算法可以直接嵌入到PFA處理中，精確地補(bǔ)償了慣導(dǎo)測(cè)量精度不足引起的越距離單元徙動(dòng)(Range Cell Migration, RCM)和相位誤差，且對(duì)于低對(duì)比度、低信噪比場(chǎng)景數(shù)據(jù)有良好的聚焦性能。最后，利用仿真實(shí)驗(yàn)和實(shí)測(cè)機(jī)載聚束SAR數(shù)據(jù)驗(yàn)證了所提算法的有效性。
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關(guān)鍵詞:
- 合成孔徑雷達(dá) /
- 極坐標(biāo)格式算法 /
- 自聚焦 /
- 參數(shù)化最小熵 /
- 對(duì)比度增強(qiáng)
Abstract: Equipped with an airborne spotlight SAR, inertia navigation system can not measure the motion errors with the required accuracy for high resolution SAR imaging, which may degrade severely the quality of a SAR image. In this paper, a novel autofocus algorithm that can be directly embedded in Polar Format Algorithm (PFA) is proposed, that is, a Hybrid Multistage Parameterized Minimum Entropy (HMPME) algorithm to proceed Range Cell Migration (RCM) correction and a scaled-stepsize iterative phase correction method based on Contrast Enhancement (CE). The autofocus processing accurately compensates the effects of range cell migration and phase errors. Also, this algorithm is most robust in processing images of low contrast and low signal-to-noise ratio. Finally, simulations and experiments with real spotlight SAR data validate the effectiveness of the proposed algorithm.-
Key words:
- SAR /
- Polar Format Algorithm (PFA) /
- Autofocus /
- Parameterized minimum entropy /
- Contrast enhancement
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張磊. 高分辨SAR/ISAR成像及誤差補(bǔ)償技術(shù)研究[D]. [博士論文], 西安電子科技大學(xué), 2012. Zhang Lei. Study on high resolution SAR/ISAR imaging and error correction[D]. [Ph.D. dissertation], Xidian University, 2012. Yang Lei, Xing Meng-dao, Wang Yong, et al.. Compensation for the NsRCM and phase error after polar format resampling for airborne spotlight SAR raw data of high resolution[J]. IEEE Geoscience and Remote Sensing Letters, 2013, 10(1): 165-169. Carrara G, Goodman S, and Majewski M. Spotlight Synthetic Aperture Radar: Signal Processing Algorithm[M]. Boston, MA: Artech House, 1995: 200-244. Xu Gang, Xing Meng-dao, Zhang Lei, et al.. Robust autofocusing approach for highly squinted SAR imagery using the extended wavenumber algorithm[J]. IEEE Transactions on Geoscience and Remote Sensing, 2013, 51(10): 5031-5046. 黃大榮, 張磊, 邢孟道, 等. 基于加權(quán)最大范數(shù)的SAR自聚焦方法[J].?電子與信息學(xué)報(bào),?2014,?36(1):?202-208. Huang Da-rong, Zhang Lei, Xing Meng-dao, et al.. A weighted maximize norm method for SAR autofocus[J]. Journal of Electronics Information Technology, 2014, 36(1): 202-208. Wahl D E, Eichel P H, Ghiglia D C, et al.. Phase gradient autofocus-a robust tool for high resolution phase correction[J]. IEEE Transactions on Aerospace and Electronic Systems, 1994, 30(3): 827-835. Ye Wei, Yeo T S, and Bao Zheng. Weighted least-squares estimation of phase errors for SAR/ISAR autofocus[J]. IEEE Transactions on Geoscience and Remote Sensing, 1999, 37(5): 2487-2494. Xiong Tao, Xing Meng-dao, Wang Yong, et al.. Minimum- entropy-based autofocus algorithm for SAR data using Chebyshev approximation and method of series reversion, and its implementation in a data processor[J]. IEEE Transactions on Geoscience and Remote Sensing, 2014, 52(3): 1719-1728. Gao Yang, Yu Wei-dong, Liu Ya-bo, et al.. Sharpness-based autofocus for stripmap SAR using an adaptive-order polynomial model[J]. IEEE Geoscience and Remote Sensing Letters, 2014, 11(6): 1086-1090. Doerry A W. Autofocus correction of excessive migration in synthetic aperture radar images[R]. Sandia Laboratory, 2004. Thomas K J and Alaa K A. Monotonic iterative algorithm for minimum-entropy autofocus[C]. IEEE International Conference on Image Processing, Atlanta, USA, 2006: 645-648. Josse K. Image reconstruction and restoration using constrained optimization algorithms[D]. [Ph.D. dissertation], Purdue University, 1996. -
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