舰船科学技术  2020, Vol. 42 Issue (8): 162-166    DOI: 10.3404/j.issn.1672-7649.2020.08.030 PDF

Spatial correlation analysis of electric field in the marine environment of typical shallow sea
CHEN Xing, YUE Rui-yong, JIANG Kai-na, ZHAO Zhe
Dalian Scientific Test and Control Technology Institute, Dalian 116013, china
Abstract: The electric field of marine environment is the background field and interference field of ship electric field detection. The study and analysis of the frequency and spatial correlation characteristics of the electric field in the marine environment can provide support for the effective extraction of the electric field signal characteristics of ships in the ocean. This paper analyzes the observation data of the marine environment in a certain area of the North Yellow Sea of china, the electric field data of four typical frequency bands are obtained by the frequency division filtering associated with the field source factors. The time-domain and polarization characteristics of each frequency band are analyzed, and the data correlation of different measurement objects in the same frequency band is studied. The analysis results show that: 0.1–1 Hz、5–10 Hz bands has a good correlation with the environment electric field; DC–0.1 Hz、1–5 Hz bands has a bad correlation with the environment electric field; there is a certain phase shift in the electric field of different positions in space, the consistency of environmental electric field signal can be improved by phase compensation, it can provide a basis for the suppression of environmental electric field.
Key words: marine environmental electric field     time-frequency characteristics     spatial correlation
0 引　言

1 海洋环境电场数据预处理

2 环境电场信号的时频特性、矢量极化方向特征分析

2.1 信号的时域特征分析

 图 1 不同测量体、不同频段、不同分量样本数据时域分析曲线 Fig. 1 Time domain analysis curves of sample data of different measuring bodies, different frequency bands, and different components

2.2 信号的频域特征分析

 图 2 不同频段样本数据频域分析曲线 Fig. 2 Frequency domain analysis curves of sample data of different measuring bodies, different frequency bands, and different components

2.3 信号的极化方向特征分析

 图 3 不同测量体、不同频段、不同分量样本数据极化图 Fig. 3 Polarization diagram of sample data of different measuring bodies, different frequency bands, and different components

3 环境电场信号归一化相关性分析

 $R_{x y}(\tau)=\lim\limits _{T \rightarrow \infty} \frac{1}{T} \int_{0}^{T} x(t) \cdot y(t+\tau) {\rm{d}} t{\text{。}}$ (1)

 图 4 不同分量环境电场归一化相关性曲线 Fig. 4 Normalized correlation curves of environmental electric fields with different components

4 环境电场信号的相位补偿

 图 5 三个频段的相位补偿 Fig. 5 Phase compensation for three frequency bands

1） $\mathrm{D}\mathrm{C}\sim0.1\;\mathrm{H}\mathrm{z}$ ，两环境电场信号相位补偿后发现信号趋势大致相似，但相关性较差。

2） $0.1\sim1\;\mathrm{H}\mathrm{z}$ , 两环境电场信号相位补偿后发现分布趋势基本一致，相关性较好。

3） $1\sim5\;\mathrm{H}\mathrm{z}$ , 两环境电场信号相位补偿后，发现信号同步性相对较差。

4） $5\sim10\;\mathrm{H}\mathrm{z}$ ，两环境电场信号相位补偿后，呈现较为一致的分布趋势。

5 结　语

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