基于椭圆模型与改进NLCS的一站固定式大基线双站SAR成像算法

钟华; 胡剑; 张松; 孙闽红

doi:10.11999/JEIT161016

基于椭圆模型与改进NLCS的一站固定式大基线双站SAR成像算法

doi: 10.11999/JEIT161016

钟华^1, ,,
胡剑¹,
张松¹,
孙闽红¹

基金项目:

国家自然科学基金(61301248, 61271214)，中国航天科技创新基金

计量
- 文章访问数: 1282
- HTML全文浏览量: 101
- PDF下载量: 273
- 被引次数: 0
出版历程
- 收稿日期: 2016-09-30
- 修回日期: 2016-11-25
- 刊出日期: 2016-12-19

Improved NLCS Algorithm Based on Ellipse Model for One-stationary Bistatic SAR with Large Baseline

Funds:

The National Natural Science Foundation of China (61301248, 61271214), Chinese Innovation Foundation of Aerospace Science and Technology

摘要

摘要: 在一站固定式双站SAR成像处理中，该文针对距离-方位2维空变描述不够准确导致成像性能迅速下降的问题，提出一种新的椭圆模型精确描述一站固定式大基线双站SAR的距离-方位空变特性，并基于此推导了改进的非线性调频变标(NLCS)成像算法。在距离向，首先利用相位去斜完成距离去走动和多普勒中心矫正，接着对剩余距离单元徙动和距离方位高次耦合项进行了去除处理。在方位向，根据一站固定式双站SAR的2维空变特性，提出了一种用于描述回波距离-方位空变特性的椭圆模型，基于该模型对空变的回波方位调频率进行了分析，并重新推导NLCS算法的方位变标函数和方位压缩系数。理论分析与仿真结果证明，所提出的模型不仅揭示了一站固定式大基线双站SAR数据的2维空变特性，而且对回波的距离-方位空变给出了更精确的解析式描述，使得基于该模型改进的NLCS算法可以获得更好的成像处理效果。
- SAR成像 /
- 双站SAR /
- 一站固定式 /
- 非线性调频变标 /
- 椭圆模型
Abstract: In One-Stationary Bistatic Synthetic Aperture Radar (OS-BiSAR) imaging, imprecise description of 2-D range-azimuth space-variant property usually leads to deterioration of final SAR image rapidly. In order to solve this issue, a new ellipse model is proposed to precisely describe range-azimuth space-variant property of OS-BiSAR with large baseline, and an improved Non-Linear Chirp Scaling (NLCS) algorithm is also derived based on this model. First, a phase de-ramp operation is performed to remove the linear Range Cell Migration (RCM) and Doppler centroid in range frequency domain. Then, the residual RCM and high order range-azimuth coupling terms are removed. Thirdly, a new ellipse model is established to describe range-azimuth space-variant property of OS-BiSAR, and then the azimuth frequency modulation rate of space-variant echo is analyzed. Moreover, azimuth scaling function of NLCS and azimuth compression factors are re-derived. Theoretical analysis and simulation results show that the proposed model not only reveals the property of 2-D azimuth-variant in OS-BiSAR, but also provides a precise analytical expression to depict the 2-D range-azimuth space-variant property of OS-BiSAR. Furthermore, simulation results validate that the improved NLCS algorithm based on this new model has high imaging performance.
- SAR imaging /
- Bistatic SAR /
- One-stationary /
- Non-Linear Chirp Scaling (NLCS) /
- Ellipse model

HTML全文

参考文献(18)

杨建宇. 双基地合成孔径雷达技术[J]. 电子科技大学学报, 2016, 45(4): 482-501. doi: 10.3969/J.issn.1001-0548.2016.04. 001.

YANG J Y. Bistatic synthetic aperture radar technology[J]. Journal of University of Electronic Science and Technology of China, 2016, 45(4): 482-501. doi: 10.3969/J.issn.1001-0548. 2016.04.001.

曾涛. 双基地合成孔径雷达发展现状与趋势分析[J]. 雷达学报, 2012, 1(4): 329-341. doi: 10.3724/SP.J.1300.2012.20093.

ZENG T. Bistatic SAR: State of the art and development trend[J]. Journal of Radars, 2012, 1(4): 329-341. doi: 10. 3724/SP.J.1300.2012.20093.

孟自强, 李亚超, 邢孟道, 等. 基于斜视等效的弹载双基前视SAR相位空变校正方法[J]. 电子与信息学报, 2016, 38(3): 613-621. doi: 10.11999/JEIT150782.

MENG Ziqiang, LI Yachao, XING Mengdao, et al. Phase space-variance correction method for missile-borne bistatic forward-looking SAR based on equivalent range equation[J]. Journal of Electronics Information Technology, 2016, 38(3): 613-621. doi: 10.11999/JEIT150782.

LI Z Y, WU J J, HUANG Y L, et al. Ground-moving target imaging and velocity estimation based on mismatched compression for bistatic forward-looking SAR[J]. IEEE Transactions on Geoscience and Remote Sensing, 2016, 54(6): 3277-3291. doi: 10.1109/TGRS.2016.2514494.

CHEN S, YUAN Y, ZHANG S N, et al. A new imaging algorithm for forward-looking missile-borne bistatic SAR[J]. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2016, 9(4): 1543-1552. doi: 10.1109/JSTARS.2015.2507260.

ZHANG H, DENG Y K, WANG R, et al. Spaceborne/ stationary bistatic SAR imaging with TerraSAR-X as an illuminator in staring-spotlight mode[J]. IEEE Transactions on Geoscience and Remote Sensing, 2016, 54(9): 5203-5216. doi: 10.1109/TGRS.2016.2558294.

WANG R, WANG W, SHAO Y F, et al. First bistatic demonstration of digital beamforming in elevation with TerraSAR-X as an illuminator[J]. IEEE Transactions on Geoscience and Remote Sensing, 2016, 54(2): 842-849. doi: 10.1109/TGRS.2015.2467176.

ZENG T, HU C, WU L X, et al. Extended NLCS algorithm of BiSAR systems with a squinted transmitter and a fixed receiver: Theory and experimental confirmation[J]. IEEE Transactions on Geoscience and Remote Sensing, 2013, 51(10): 5019-5030. doi: 10.1109/TGRS.2013.2276048.

QIU X L, HU D H, and DING C B. An improved NLCS algorithm with capability analysis for one-stationary BiSAR [J]. IEEE Transactions on Geoscience and Remote Sensing, 2008, 46(10): 3179-3186. doi: 10.1109/TGRS.2008.921569.

WONG F H and YEO T S. New applications of nonlinear chirp scaling in SAR data processing[J]. IEEE Transactions on Geoscience and Remote Sensing, 2001, 39(5): 946-953. doi: 10.1109/36.921412.

WONG F H, CUMMING I G, and NEO Y L. Focusing bistatic SAR data using the nonlinear chirp scaling algorithm[J]. IEEE Transactions on Geoscience and Remote Sensing, 2008, 46(9): 2493-2505. doi: 10.1109/TGRS.2008. 917599.

LI D, LIAO G S, WANG W, et al. Extended azimuth nonlinear chirp scaling algorithm for bistatic SAR processing in high-resolution highly squinted mode[J]. IEEE Geoscience and Remote Sensing Letters, 2014, 11(6): 1134-1138. doi: 10.1109/LGRS.2013.2288292.

WANG W, LIAO G S, LI D, et al. Focus improvement of squint bistatic SAR data using azimuth nonlinear chirp scaling[J]. IEEE Geoscience and Remote Sensing Letters, 2014, 11(1): 229-233. doi: 10.1109/LGRS.2013.2254106.

LI Z Y, WU J J, YI Q Y, et al. Bistatic forward-looking SAR ground moving target detection and imaging[J]. IEEE Transactions on Aerospace and Electronic Systems, 2015, 51(2): 1000-1016. doi: 10.1109/TAES.2014.130539.

NEO Y L, WONG F H, and CUMMING I G. A two- dimensional spectrum for bistatic SAR processing using series reversion[J]. IEEE Geoscience and Remote Sensing Letters, 2007, 4(1): 93-96. doi: 10.1109/LGRS.2006.885862.

施引文献

资源附件(0)

访问统计