基于布里渊激光雷达的海水温度和盐度反演

Inversion of Seawater Temperature and Salinity Based on Brillouin Lidar

作为一种新型的激光探测雷达,布里渊激光雷达可以用于海水参数的监测。针对现有的布里渊激光雷达反演模型存在反演精度和参数范围较小的缺点,将频移和线宽作为自变量,采用最小二乘法对温度与盐度进行了拟合,提出了新的温度与盐度的反演模型。该模型提高了海水温度和盐度的反演精度与范围,并从灵敏度、误差、不确定度三个方面对反演模型进行了分析。结果表明,利用布里渊频移和线宽可以实现海洋温度和盐度的同步监测。在温度反演模型中,布里渊线宽对温度的影响要大于频移对温度的影响,新的模型温度反演范围从15℃≤T≤30℃扩大为10℃≤T≤30℃,最大误差为0.17℃,平均误差为0.07℃,平均相对误差为0.27%,比现有模型的精度提高了63.16%;在盐度反演模型中,布里渊频移对盐度的影响要大于线宽对盐度的影响,该模型的反演范围也从30‰≤S≤35‰扩大为15‰≤S≤35‰,最大误差为0.20‰,平均误差为0.09‰,平均相对误差为0.29%,比现有模型的精度提高了77.50%。研究结果对布里渊激光雷达探测海水温度和盐度具有指导意义。

As a new type of laser detection radar,Brillouin lidar can be used for monitoring seawater parameters.In view of the disadvantage of the existing Brillouin lidar inversion models that have smaller inversion accuracy and parameter range,the new inversion model for temperature and salinity is proposed by using the least squares method with frequency shift and linewidth as independent variables.This model improves the inversion accuracy and inversion range of temperature and salinity,and the inversion model is analyzed in terms of sensitivity,error and uncertainty.The results show that the Brillouin frequency shift and linewidth can be used to achieve simultaneous monitoring of ocean temperature and salinity.In the temperature inversion model,the effect of Brillouin linewidth on temperature is greater than that of frequency shift,and the temperature inversion range of the new model is extended from 15℃≤T<30℃ to 10℃≤T≤30℃ with a maximum error of 0.17℃,an average error of 0.07°C and an average relative error is 0.27%,which is 63.16%better than the accuracy of the existing model.In the salinity inversion model,the effect of Brillouin frequency shift on salinity is greater than that of linewidth,and the inversion range of the model is expanded from 3‰≤S<35‰ to 15‰≤S<35‰,with a maximum error of 0.2‰,an average error of 0.09‰ and an average relative error is 0.29%,which is 77.50%better than the accuracy of the existing model.The research results in this paper have guiding significance for Brillouin lidar to detect seawater temperature and salinity.