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微多普勒特征提取作为一种常用的时频分析工具, 对微动目标特征的提取重构具有重要意义. 为了更好地研究多运动的微多普勒效应, 提出了一种运动姿态分类方法. 按照目标频移是否随时间变化可以将运动姿态分为频移时变运动和频移时不变运动. 频移时变运动包括平移、翻滚和振动. 针对这种运动应分析对比不同时间对应的瞬态频移, 频移时不变运动主要为旋转运动. 本文通过微多普勒效应理论结合电磁波频域模型, 实现3D运动目标微动特性提取的仿真建立目标, 分析不同环境条件例如晴天阴天、有无湍流对探测的影响, 为后续实验研究奠定理论基础. 开展基于收发同置系统的多特征运动目标的微多普勒频移探测实验, 实验结果表明, 不同目标位置上频移的幅度、正负性和谱线宽度旨在反演目标形状、运动姿态、运动方向和速度. 利用FFTshift函数对一维数据进行解调分析, 实现三维时间-频率-强度关系的研究. 本研究实现了对目标宏观形状特性的测量以及微观运动信息的提取, 为雷达探测和识别奠定基础.
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关键词:
- 微多普勒效应 /
- 多特征运动 /
- 目标识别 /
- 时间-频率-强度关系
The micro-Doppler effect is a physical phenomenon generated by the micro-motion of objects and their components, which have a significant influence on improving radar detection and resolution capability and also enhancing the radar imaging and target recognition performance. The extraction of micro-Doppler frequency, as a commonly used time-frequency analysis tool, is of great significance in extracting and reconstructing the signal with micro-motion targets. The micro-motion characteristics for moving targets can be verified by using simulation through combining the theory of micro-Doppler effect with the frequency domain model of electromagnetic waves. The simulation research on the micro-motion characteristics of a three-dimensional target is conducted by using the finite element method. The influences of environmental conditions such as relative humidity, visibility, and the presence or absence of turbulence on echo intensity and time-frequency relationship are investigated theoretically. The simulation results indicate that parameters such as relative humidity and visibility, which affect the atmospheric attenuation coefficient, can reduce echo intensity and the period of time-frequency curve. By triggering off beam drift in the transmission path, turbulence can lead to “frequency shift deformation” of the time-frequency curve, degrading the extraction of target motion attitude. A motion attitude classification method is proposed in order to study the micro-Doppler effect better. According to whether the frequency shift changes with time, the motion attitude can be divided into frequency shift time-invariant motion and time-variant motion. Frequency shift time-variant motion includes translation, rolling and vibration. Vibration and rolling are motions that periodically change with time, requiring the comparison of instantaneous frequency shifts at any three times within a cycle. Translation is a time-variant motion with irregular frequency shifts over time, which involves studying instantaneous frequency shifts at any three times. Transient frequency shifts should be analyzed and compared at different times for these motions. The frequency shift time-invariant motion is mainly rotation obtained experimental results indicate that the amplitude, plus-minus, and spectral width of frequency shift at different positions are aimed at inverting the target shape, attitude, direction and velocity. Demodulating one-dimensional data obtained from the FFTshift function can obtain the time-frequency-intensity relationship. This multi-parameter analysis method is a multi-dimensional processing method widely used in the fields of radar, sonar, and communication. The above research is conductive to the measurement of target macroscopic shape properties and the extraction of microscopic motion information, which lays the foundation for radar detection and recognition.-
Keywords:
- micro-Doppler effect /
- multi-feature motion /
- target recognition /
- time-frequency-intensity relationship
[1] 郭力仁, 胡以华, 董骁, 李敏乐 2018 67 150701Google Scholar
Guo L R, Hu Y H, Dong X, Li M L 2018 Acta Phys. Sin. 67 150701Google Scholar
[2] Peng J Q, Xu W F, Liang B, Wu A G 2018 IEEE Sens. J. 19 8Google Scholar
[3] 高飞, 南恒帅, 黄波, 汪丽, 李仕春, 王玉峰, 刘晶晶, 闫庆, 宋跃辉, 华灯鑫 2018 67 030701Google Scholar
Gao F, Nan H S, Huang B, Wang L, Li S C, Wang Y F, Liu J J, Yan Q, Song Y H, Hua D X 2018 Acta Phys. Sin. 67 030701Google Scholar
[4] 李艳辉, 吴振森, 宫彦军, 张耿, 王明军 2010 59 6988Google Scholar
Li Y H, Wu Z S, Gong Y J, Zhang G, Wang M J 2010 Acta Phys. Sin. 59 6988Google Scholar
[5] Liu Y, Zhang Z, Burla M, Eggleton B J 2022 Laser Photonics Rev. 4 16Google Scholar
[6] Bradley M, Sabatier J M 2012 J. Acoust. Soc. Am. 131 3Google Scholar
[7] Thayaparan T, Stanković L, Djurović I 2008 J. Franklin. I 345 700Google Scholar
[8] Anderson M G 2008 Ph. D. Dissertation (Austin: The university of Texas at Austin
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[10] Terras R 1981 J. Conput. Phys. 39 233Google Scholar
[11] Antar M M Y, Hendry A 1985 Electron. Lett. 21 22Google Scholar
[12] Zhao Y C, Su Y 2021 IET. Microw. Antenna P. 15 7Google Scholar
[13] Inomata H, Igarashi T 1975 Jpn. J. Appl. Phys. 14 11Google Scholar
[14] Chen V C, Li F, Ho S S, Wechsler H 2006 IEEE T. Aero. Elec. Sys. 42 1Google Scholar
[15] Chen V C 1997 Opt. Eng. 4 36
[16] 王童, 童创明, 李西敏, 李昌泽 2015 64 210301Google Scholar
Wang T, Tong C M, Li X M, Li C Z 2015 Acta Phys. Sin. 64 210301Google Scholar
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[19] Chen S, Zhang H Y, Jin F H, Zhao C M, Wang L 2023 Heliyon 9 e16728Google Scholar
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[23] Kim J, Baik J 2004 Atmos. Environ. 38 19Google Scholar
[24] 陈燕 2009 气象与环境科学 32 4Google Scholar
Chen Y 2009 Meteor. Environ. Sci. 32 4Google Scholar
[25] 冷长林 2007 博士学位论文 (天津: 天津大学)
Leng C L 2007 Ph. D. Dissertation (Tianjin: Tianjin University
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图 8 自旋1锥体上位置的频移示意图 (a)—(c)顺时针自旋1锥体上位置①—⑤的频移; (d)—(f)逆时针自旋1锥体上位置①—⑤的频移
Fig. 8. Diagrams of micro-Doppler at different positions of the cone with rotation 1: (a)—(c) Frequency shift of a cone at positions ①—⑤ with the clockwise rotation 1; (d)—(f) frequency shift of a cone at positions ①—⑤ with the counterclockwise rotation 1.
图 10 振动目标上图2(a)中位置①处一个周期内三个时刻对应的频移
Fig. 10. Frequency shift at three times in a cycle on position ① in Fig. 2 (a) of a vibrating target.
图 11 翻滚目标不同位置的微多普勒频移图 (a)—(e)顺时针翻滚圆锥上位置①—⑤处的频移; (f)—(j)逆时针翻滚圆锥上位置①—⑤处的频移
Fig. 11. Diagrams of micro-Doppler frequency shift at different positions of rolling targets: (a)—(e) Frequency shifts at positions ①—⑤ of a clockwise rolling cone; (f)—(j) frequency shifts at positions ①—⑤ of a counterclockwise rolling cone.
表 1 不同位置上的频移和频谱宽度
Table 1. Frequency shift and spectrum width at different locations.
物理意义 赋值 备注 温度 298 K 实验室温度为25 ℃ 相对湿度 0.5 晴天 0.8 阴天 能见度 23 km 晴天 12 km 阴天 室内风速 ~0.1 m/s — 材料 空气 — 铝 — 欧拉角 (20°, 30°, 50°) — 光斑半径 0.2 cm — 表 2 仿真中使用的大气湍流模型参数
Table 2. Parameters used in numerical simulations.
参数 Cε1 Cε2 Cμ σk σε 赋值 1.44 1.92 0.09 1 1.3 表 3 不同位置上的频移和频谱宽度
Table 3. Frequency shift and spectral width at different positions.
位置 峰值
/MHz正负性 谱线宽度
/MHz注释 ① 0.112 正值 0.192 轴对称 ② 0.122 0.117 ①' –0.083 负值 0.123 ②' -0.095 0.060 ③ 0.199 正值 0.100 轴对称 ④ –0.143 负值 0.145 ③' –0.088 负值 0.061 ④' 0.720 正值 0.057 ⑤ –0.012 约为 0 0.130 位于对称轴上 ⑥ 0.002 0.117 ⑦ 0.020 0.0017 -
[1] 郭力仁, 胡以华, 董骁, 李敏乐 2018 67 150701Google Scholar
Guo L R, Hu Y H, Dong X, Li M L 2018 Acta Phys. Sin. 67 150701Google Scholar
[2] Peng J Q, Xu W F, Liang B, Wu A G 2018 IEEE Sens. J. 19 8Google Scholar
[3] 高飞, 南恒帅, 黄波, 汪丽, 李仕春, 王玉峰, 刘晶晶, 闫庆, 宋跃辉, 华灯鑫 2018 67 030701Google Scholar
Gao F, Nan H S, Huang B, Wang L, Li S C, Wang Y F, Liu J J, Yan Q, Song Y H, Hua D X 2018 Acta Phys. Sin. 67 030701Google Scholar
[4] 李艳辉, 吴振森, 宫彦军, 张耿, 王明军 2010 59 6988Google Scholar
Li Y H, Wu Z S, Gong Y J, Zhang G, Wang M J 2010 Acta Phys. Sin. 59 6988Google Scholar
[5] Liu Y, Zhang Z, Burla M, Eggleton B J 2022 Laser Photonics Rev. 4 16Google Scholar
[6] Bradley M, Sabatier J M 2012 J. Acoust. Soc. Am. 131 3Google Scholar
[7] Thayaparan T, Stanković L, Djurović I 2008 J. Franklin. I 345 700Google Scholar
[8] Anderson M G 2008 Ph. D. Dissertation (Austin: The university of Texas at Austin
[9] Ji J Z, Jiang J X, Allann A A, Shu C, Huang P 2017 Optik 150 1Google Scholar
[10] Terras R 1981 J. Conput. Phys. 39 233Google Scholar
[11] Antar M M Y, Hendry A 1985 Electron. Lett. 21 22Google Scholar
[12] Zhao Y C, Su Y 2021 IET. Microw. Antenna P. 15 7Google Scholar
[13] Inomata H, Igarashi T 1975 Jpn. J. Appl. Phys. 14 11Google Scholar
[14] Chen V C, Li F, Ho S S, Wechsler H 2006 IEEE T. Aero. Elec. Sys. 42 1Google Scholar
[15] Chen V C 1997 Opt. Eng. 4 36
[16] 王童, 童创明, 李西敏, 李昌泽 2015 64 210301Google Scholar
Wang T, Tong C M, Li X M, Li C Z 2015 Acta Phys. Sin. 64 210301Google Scholar
[17] Li T M, Wen B Y, Tian Y W, Wang S J, Yin Y K 2019 IEEE Access 7 101527Google Scholar
[18] Chen S, Zhang H Y, Zhao C M, Chen H, Fan Y, Wang L 2022 Def. Technol. 28 146Google Scholar
[19] Chen S, Zhang H Y, Jin F H, Zhao C M, Wang L 2023 Heliyon 9 e16728Google Scholar
[20] Jia J F, Kim H K, Hielscher A H 2015 J. Quant. Spectrosc. Ra. 167 10Google Scholar
[21] Abushagur A A G, Abbou F M, Abdullah M, Misran N 2011 Opt. Eng. 50 7
[22] Cheng X, Zhang D Z, Li X, Li X T, Chen R J 2021 J. Phys. Conf. Ser. 1971 1Google Scholar
[23] Kim J, Baik J 2004 Atmos. Environ. 38 19Google Scholar
[24] 陈燕 2009 气象与环境科学 32 4Google Scholar
Chen Y 2009 Meteor. Environ. Sci. 32 4Google Scholar
[25] 冷长林 2007 博士学位论文 (天津: 天津大学)
Leng C L 2007 Ph. D. Dissertation (Tianjin: Tianjin University
[26] Philip G, Sammy W H, Thomson J A, Dale L B 2000 Proc. Spie. 4035 2000Google Scholar
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