海缆是海缆基础设施供电和通信的关键载体,海缆监测对于保障海缆基础设施安全稳定运行具有重要工程意义。针对海缆扰动监测需求开展海缆扰动探测试验研究。首先,搭建基于分布式光纤传感技术的海缆扰动探测试验系统,并接入南海深海海底...海缆是海缆基础设施供电和通信的关键载体,海缆监测对于保障海缆基础设施安全稳定运行具有重要工程意义。针对海缆扰动监测需求开展海缆扰动探测试验研究。首先,搭建基于分布式光纤传感技术的海缆扰动探测试验系统,并接入南海深海海底观测网试验系统海缆暗光纤进行扰动探测试验,试验结果表明本系统能够有效探测铁锹拍击、车辆振动、海水冲刷及台风影响引起的海缆扰动。然后,根据海缆光纤瑞利背向散射(Rayleigh Backscattering,RBS)幅度信号特征,提出一种基于双向长短期记忆(Bidirectional Long Short-Term Memory,BiLSTM)神经网络的海缆扰动定位方法,本方法以海缆光纤RBS幅度信号的谱熵和瞬时频率作为特征参量输入,使用海缆光纤RBS幅度信号样本对本方法进行测试,结果表明本方法对海缆沿线扰动信号和非扰动信号的平均检测准确率高于99.6%。将海缆扰动探测试验系统与海缆扰动定位方法结合应用于海缆监测可有效探测海缆沿线扰动。展开更多
A novel scheme for all-optical broadcast ultra-wideband(UWB) monocycle pulses generation based on cross-phase modulation(XPM) in semiconductor fiber ring laser(SFRL) is proposed, in which three UWB positive or negativ...A novel scheme for all-optical broadcast ultra-wideband(UWB) monocycle pulses generation based on cross-phase modulation(XPM) in semiconductor fiber ring laser(SFRL) is proposed, in which three UWB positive or negative monocycle pulses can be generated simultaneously. A comprehensive broad-band dynamic model for this kind of all-optical broadcast UWB monocycle sources is established, which is further applied to numerically analyze the impacts of injection current of semiconductor optical amplifier(SOA), the power and wavelength of the signal light on the performance of the UWB positive monocycle pulses with higher power spectral density. The results show that the spectra of the UWB positive and negative monocycle pulses generated by this scheme match the Federal Communications Commission(FCC) definition quite well. Three UWB positive monocycle pulses with better performance can be obtained when the power of signal light is at a high level, and three other UWB positive monocycle pulses with good tolerance to both the injection current of the SOA and the wavelength of the signal light can be obtained. In addition, the powers of the lasing light coupled into the SFRL should not be strong to obtain three UWB positive monocycle pulses with better performance.展开更多
An adaptive nonlinear prediction algorithm is proposed to predict ocean reverberation based on the phase space reconstruction of nonlinear dynamic system. The prediction algorithm is tested by experimental reverberati...An adaptive nonlinear prediction algorithm is proposed to predict ocean reverberation based on the phase space reconstruction of nonlinear dynamic system. The prediction algorithm is tested by experimental reverberation data measured in two areas, and the one-step forward prediction results are in good agreement with the experimental data. If the errors between the predicted and experimental data are chosen as the variable to detect the target in the reverberation series, the reverberation is suppressed and the signal-to-reverberation ratio is improved.展开更多
文摘海缆是海缆基础设施供电和通信的关键载体,海缆监测对于保障海缆基础设施安全稳定运行具有重要工程意义。针对海缆扰动监测需求开展海缆扰动探测试验研究。首先,搭建基于分布式光纤传感技术的海缆扰动探测试验系统,并接入南海深海海底观测网试验系统海缆暗光纤进行扰动探测试验,试验结果表明本系统能够有效探测铁锹拍击、车辆振动、海水冲刷及台风影响引起的海缆扰动。然后,根据海缆光纤瑞利背向散射(Rayleigh Backscattering,RBS)幅度信号特征,提出一种基于双向长短期记忆(Bidirectional Long Short-Term Memory,BiLSTM)神经网络的海缆扰动定位方法,本方法以海缆光纤RBS幅度信号的谱熵和瞬时频率作为特征参量输入,使用海缆光纤RBS幅度信号样本对本方法进行测试,结果表明本方法对海缆沿线扰动信号和非扰动信号的平均检测准确率高于99.6%。将海缆扰动探测试验系统与海缆扰动定位方法结合应用于海缆监测可有效探测海缆沿线扰动。
基金supported by the Hainan Provincial Natural Science Foundation of China(No.620MS078).
文摘A novel scheme for all-optical broadcast ultra-wideband(UWB) monocycle pulses generation based on cross-phase modulation(XPM) in semiconductor fiber ring laser(SFRL) is proposed, in which three UWB positive or negative monocycle pulses can be generated simultaneously. A comprehensive broad-band dynamic model for this kind of all-optical broadcast UWB monocycle sources is established, which is further applied to numerically analyze the impacts of injection current of semiconductor optical amplifier(SOA), the power and wavelength of the signal light on the performance of the UWB positive monocycle pulses with higher power spectral density. The results show that the spectra of the UWB positive and negative monocycle pulses generated by this scheme match the Federal Communications Commission(FCC) definition quite well. Three UWB positive monocycle pulses with better performance can be obtained when the power of signal light is at a high level, and three other UWB positive monocycle pulses with good tolerance to both the injection current of the SOA and the wavelength of the signal light can be obtained. In addition, the powers of the lasing light coupled into the SFRL should not be strong to obtain three UWB positive monocycle pulses with better performance.
基金supported by the National Natural Science Foundation of China(10734100)supportedby the Knowledge Innovation Program of the Chinese Academy of Sciences.
文摘An adaptive nonlinear prediction algorithm is proposed to predict ocean reverberation based on the phase space reconstruction of nonlinear dynamic system. The prediction algorithm is tested by experimental reverberation data measured in two areas, and the one-step forward prediction results are in good agreement with the experimental data. If the errors between the predicted and experimental data are chosen as the variable to detect the target in the reverberation series, the reverberation is suppressed and the signal-to-reverberation ratio is improved.
