基于改进sinc插值的变PRF采样聚束SAR成像

陈世阳; 黄丽佳; 俞雷

doi:10.12000/JR18095

基于改进sinc插值的变PRF采样聚束SAR成像

doi: 10.12000/JR18095

陈世阳^1,2,3,4,,
黄丽佳^1,2, ,,
俞雷^4,

①.
中国科学院电子学研究所北京 100190
②.
中国科学院空间信息处理与应用系统技术重点实验室北京 100190
③.
中国科学院大学电子电气与工程学院北京 100049
④.
北京航空航天大学电子信息工程学院北京 100191

基金项目: 国家自然科学基金(61331017)

详细信息

作者简介:
陈世阳(1994–)，男，硕士研究生，研究方向为合成孔径雷达信号处理。Email: m15528309300@163.com

黄丽佳(1984–)，女，博士，副研究员，硕士生导师，研究方向为合成孔径雷达信号处理与图像分析。Email: iecas8huanglijia@163.com

俞雷：俞雷(1979–)，男，博士生，高级工程师。研究方向为合成孔径雷达系统、雷达信号处理和遥感应用处理。E-mail: ylanlei@buaa.edu.cn

通讯作者:
黄丽佳 iecas8huanglijia@163.com

中图分类号: TN958
计量
- 文章访问数: 3190
- HTML全文浏览量: 1217
- PDF下载量: 235
- 被引次数: 0
出版历程
- 收稿日期: 2018-11-14
- 修回日期: 2019-02-22
- 网络出版日期: 2019-08-28

A Novel sinc Interpolation for Continuous PRF Sampled Sequences Reconstruction in Spotlight SAR

CHEN Shiyang^{1,2,3,4
,},
HUANG Lijia^{1,2
, ,},
YU Lei^4
,

①.
Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China
②.
Key Laboratory of Technology in Geo-Spatial Information Processing and Application System, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China
③.
School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
④.
School of Electronics and Information Engineering, Beihang University, Beijing 100191, China

Funds: The National Science Foundation of China (61331017)

More Information

Corresponding author: HUANG Lijia, iecas8huanglijia@163.com

摘要

摘要: 该文针对周期性变PRF采样高分辨率聚束模式合成孔径雷达(SAR)提出了一种改进的两步成像算法。变脉冲重复频率(PRF)设计可解决固定盲区等问题，是解决星载SAR高分宽幅矛盾的一种有效手段，但变PRF采样会引起频谱混叠和虚假目标等问题。该文从离散非均匀傅里叶变换原理出发，推导改进sinc插值核函数并建立了时域-时域的回波重建方法，将变PRF采样回波重构为均匀采样回波。此外将改进sinc插值与两步式成像算法结合，据此发展出针对非均匀采样回波的改进两步式聚束SAR成像算法，拓展了传统两步式成像算法的使用范围。仿真数据和实际数据处理结果验证了成像算法的有效性和精确性，并且改进sinc插值具备更高的计算效率。
- 聚束SAR /
- 改进sinc插值 /
- 变PRF采样 /
- 高分辨率 /
- 宽测绘带
Abstract: This paper focuses on an improved imaging-algorithm for the spotlight Synthetic Aperture Radar (spotlight SAR) with continuous Pulse Repetition Frequency (PRF) variation in extremely high-resolution imaging-process. PRI variation is conventionally employed to resolve the problem of fixed blind ranges as well as the conflict of high-resolution and wide-swath; however, there are problems such as spectrum aliasing and ambiguous targets caused by nonuniform sampling. In this study, a novel sinc interpolation method is proposed to reconstruct a uniformly sampled signal from non-uniform Fourier Transform samples. Then a two-step processing approach combined with the novel sinc interpolation method is presented in the process of non-uniformly sampled echo imaging. The simulation proves the validity and accuracy of the proposed imaging algorithm. In addition, the computational cost of the novel sinc interpolation is further reduced compared to that of non-uniform Fourier transformation.
- Spotlight SAR /
- Modified sinc-interpolation /
- PRF Variation /
- High resolution /
- Wide swath

HTML全文

图 1 固定PRF时，排除星下点干扰和发射干扰后的时序图

Figure 1. Illustration of PRF excluded zones as a result of transmit and nadir interference

下载: 全尺寸图片幻灯片

图 2 给定参数下的盲区分布图

Figure 2. Blind ranges location for a given parameters of different PRI variations

下载: 全尺寸图片幻灯片

图 3 基于改进sinc插值的两步式成像算法流程图

Figure 3. Procedure of the two-step processing approach based on the modified sinc interpolation

下载: 全尺寸图片幻灯片

图 4 慢变PRI序列两步式成像方位包络

Figure 4. Azimuth envelope of slow PRI change by different two-step algorithms

下载: 全尺寸图片幻灯片

图 5 快变PRI序列两步式成像方位包络

Figure 5. Azimuth envelope of fast PRI change by different two-step algorithms

下载: 全尺寸图片幻灯片

图 6 高分三号数据处理结果

Figure 6. Experiments on GF-3 data

下载: 全尺寸图片幻灯片

表 1 快变慢变仿真参数

Table 1. SAR parameters of two types of PRI variation

参数	值
视角(°)	49
慢变PRF变化范围(Hz)	3243～3355
快变PRF变化范围(Hz)	3243～5964
方位向瞬时多普勒带宽(Hz)^*	2703
方位向总带宽(Hz)^**	72703
脉冲持续时间(μs)	30
慢变序列的一周期内脉冲数量	110
快变序列的一周期内脉冲数量	64
方位向分辨率	0.1
成像场景宽度(km)	8
表示聚束成像模式中的方位向瞬时带宽，*表示聚束成像模式中的方位向总带宽，即瞬时带宽与场景固定带宽之和

下载: 导出CSV

表 2 计算量对比

Table 2. Complexity of calculation

算法	乘法运算量	加法运算量	总运算量
NUDFT	N_a ²	N_a(N_a–1)	N_a(2N_a–1)
改进sinc插值	N_aL	N_a(L–1)	N_a(2L–1)

下载: 导出CSV

表 3 虚假电平指标测量结果

Table 3. Estimation of false targets level

PRF变化方式	算法	近距目标(dB)	中距目标(dB)	远距目标(dB)
慢变PRF	传统两步式成像算法	–20.56	–48.44	–22.11
	两步式成像结合NUDFT	–71.56	–72.91	–72.57
	两步式成像结合sinc插值	–49.38	–50.17	–49.87
	两步式成像结合改进sinc插值	–67.22	–66.89	–71.61
快变PRF	传统两步式成像算法	–12.33	–31.98	–12.04
	两步式成像结合NUDFT	–54.03	–54.25	–54.57
	两步式成像结合sinc插值	–26.05	–26.11	–26.02
	两步式成像结合改进sinc插值	–56.48	–53.36	–54.95

下载: 导出CSV

参考文献(16)

[1]	丁赤飚, 刘佳音, 雷斌, 等. 高分三号SAR卫星系统级几何定位精度初探[J]. 雷达学报, 2017, 6(1): 11–16. doi: 10.12000/JR17024 DING Chibiao, LIU Jiayin, LEI Bin, et al. Preliminary exploration of systematic geolocation accuracy of GF-3 SAR satellite system[J]. Journal of Radars, 2017, 6(1): 11–16. doi: 10.12000/JR17024
[2]	洪峻, 雷大力, 王宇, 等. 宽带宽方位波束对高分辨率SAR辐射定标的影响分析[J]. 雷达学报, 2015, 4(3): 276–286. doi: 10.12000/JR15015 HONG Jun, LEI Dali, WANG Yu, et al. Wide band and wide azimuth beam effect on high-resolution synthetic aperture radar radiometric calibration[J]. Journal of Radars, 2015, 4(3): 276–286. doi: 10.12000/JR15015
[3]	聂鑫. 变波门大斜视滑动聚束SAR成像关键技术分析[J]. 电子与信息学报, 2016, 38(12): 3122–3128. doi: 10.11999/JEIT160812 NIE Xin. Research on key technique of highly squinted sliding spotlight SAR imaging with varied receiving range bin[J]. Journal of Electronics &Information Technology, 2016, 38(12): 3122–3128. doi: 10.11999/JEIT160812
[4]	赵庆超, 张毅, 王宇, 等. 基于多帧超分辨率的方位向多通道星载SAR非均匀采样信号重建方法[J]. 雷达学报, 2017, 6(4): 408–419. doi: 10.12000/JR17035 ZHAO Qingchao, ZHANG Yi, WANG R, et al. Signal reconstruction approach for multichannel SAR in azimuth based on multiframe super resolution[J]. Journal of Radars, 2017, 6(4): 408–419. doi: 10.12000/JR17035
[5]	赵耀, 邓云凯, 王宇, 等. 原始数据压缩对方位向多通道SAR系统影响研究[J]. 雷达学报, 2017, 6(4): 397–407. doi: 10.12000/JR17030 ZHAO Yao, DENG Yunkai, WANG Yu, et al. Study of effect of raw data compression on azimuth multi-channel SAR system[J]. Journal of Radars, 2017, 6(4): 397–407. doi: 10.12000/JR17030
[6]	武其松, 井伟, 邢孟道, 等. MIMO-SAR大测绘带成像[J]. 电子与信息学报, 2009, 31(4): 772–775. doi: 10.3724/SP.J.1146.2007.01959 WU Qisong, JING Wei, XING Mengdao, et al. Wide swath imaging with MIMO-SAR[J]. Journal of Electronics &Information Technology, 2009, 31(4): 772–775. doi: 10.3724/SP.J.1146.2007.01959
[7]	VILLANO M, KRIEGER G, and MOREIRA A. Staggered-SAR for high-resolution wide-swath imaging[C]. Proceedings of the IET International Conference on Radar Systems, Glasgow, UK, 2012: 1–6. doi: 10.1049/CP.2012.1600.
[8]	VILLANO M, JÄGER M, STEINBRECHER U, et al. Staggered SAR: Imaging a wide continuous swath by continuous PRI variation[C]. Proceedings of the Kleinheubacher Tagung, Miltenberg, Germany, 2014.
[9]	罗绣莲, 徐伟, 郭磊. 捷变PRF技术在斜视聚束SAR中的应用[J]. 雷达学报, 2015, 4(1): 70–77. doi: 10.12000/JR14149 LUO Xiulian, XU Wei, and GUO Lei. The application of PRF variation to squint spotlight SAR[J]. Journal of Radars, 2015, 4(1): 70–77. doi: 10.12000/JR14149
[10]	唐江文, 邓云凯, 王宇, 等. 高分辨率滑动聚束SAR BP成像及其异构并行实现[J]. 雷达学报, 2017, 6(4): 368–375. doi: 10.12000/JR16053 TANG Jiangwen, DENG Yunkai, WANG R, et al. High-resolution slide spotlight SAR imaging by BP algorithm and heterogeneous parallel implementation[J]. Journal of Radars, 2017, 6(4): 368–375. doi: 10.12000/JR16053
[11]	刘艳阳, 李真芳, 杨桃丽, 等. 一种单星方位多通道高分辨率宽测绘带SAR系统通道相位偏差时域估计新方法[J]. 电子与信息学报, 2012, 34(12): 2913–2919. doi: 10.3724/SP.J.1146.2012.00562 LIU Yanyang, LI Zhenfang, YANG Taoli, et al. A novel channel phase bias estimation method for spaceborne along-track multi-channel HRWS SAR in time-domain[J]. Journal of Electronics &Information Technology, 2012, 34(12): 2913–2919. doi: 10.3724/SP.J.1146.2012.00562
[12]	刘艳阳, 李真芳, 索志勇, 等. 一种星载多通道高分辨率宽测绘带SAR系统通道相位偏差估计新方法[J]. 电子与信息学报, 2013, 35(8): 1862–1868. doi: 10.3724/SP.J.1146.2012.01424 LIU Yanyang, LI Zhenfang, SUO Zhiyong, et al. A novel channel phase bias estimation method for spaceborne multi-channel high-resolution and wide-swath SAR[J]. Journal of Electronics &Information Technology, 2013, 35(8): 1862–1868. doi: 10.3724/SP.J.1146.2012.01424
[13]	王沛, 王翔宇, 李宁, 等. 超高分辨率机载SAR高精度子带拼接与处理方法研究[J]. 电子与信息学报, 2017, 39(10): 2325–2331. doi: 10.11999/JEIT170093 WANG Pei, WANG Xiangyu, LI Ning, et al. Investigation on high precision sub-band synthesizing and processing method for very-high-resolution airborne SAR[J]. Journal of Electronics &Information Technology, 2017, 39(10): 2325–2331. doi: 10.11999/JEIT170093
[14]	吴玉峰, 孙光才, 杨军, 等. 周期性非均匀采样实现星载SAR高分辨宽测绘带成像[J]. 电子与信息学报, 2012, 34(2): 279–286. doi: 10.3724/SP.J.1146.2011.00498 WU Yufeng, SUN Guangcai, YANG Jun, et al. High-resolution wide-swath imaging for spaceborne SAR based on periodic non-uniform sampling[J]. Journal of Electronics &Information Technology, 2012, 34(2): 279–286. doi: 10.3724/SP.J.1146.2011.00498
[15]	QIU Xue, LI Chunsheng, LI Jingwen, et al. A CZT-based continuous varying PRF polar format algorithm for highly squinted spotlight SAR[C]. Proceedings of 2015 IEEE International Geoscience and Remote Sensing Symposium, Milan, Italy, 2015: 4494–4497. doi: 1109/IGARSS.2015.7326826.
[16]	DUTT A and ROKHLIN V. Fast fourier transforms for nonequispaced data[J]. SIAM Journal on Scientific Computing, 1993, 14(6): 1368–1393. doi: 10.1137/0914081