随机噪声对海洋布里渊激光雷达测量的影响

为了分析激光雷达系统中随机噪声对海水布里渊散射谱以及温度反演精度的影响,依据布里渊散射理论及系统噪声特性,对带噪布里渊散射频谱进行了理论分析,并进行了信噪比从1dB~100dB的仿真实验。结果表明,当信噪比大于16dB时,频移和线宽的平均误差和不确定度能够控制在兆赫兹量级,温度误差和不确定度能够控制在0.2℃以内;采用实际应用中多次测量取平均的方法,10次平均能够保证0.2℃的测量精度对信噪比的要求下降到7dB。这为激光雷达在海水高精度遥感提供了指导。

Effect of random noise on oceanic Brillouin lidar measurement

In order to analyze effect of random noise of lidar system on oceanic Brillouin scattering spectroscopy and temperature inversion precision, Brillouin scattering spectrum with noise was analyzed theoretically based on Brillouin scattering theory and system noise characteristics. Simulation experiment of signal-to-noise ratio (SNR) from 1dB to 100dB was conducted. The results showed that average error and uncertainty of frequency shift and linewidth can be controlled to the order of MHz when SNR is greater than 16dB. Temperature error and uncertainty can be controlled within 0.2℃. In actual application, the average of multiple measurements is taken. The average of 10 times can ensure the requirement of SNR is smaller than 7dB with measurement accuracy of 0.2℃. The study provides the guidance for lidar remote sensing precision in seawater.