对流层散射传输损耗与大气折射率结构常数相关性研究

Research on the Correlation of Troposcatter Transmission Loss and Structure Constant of the Refractive Index

基于大气湍流非相干散射理论,采用泰勒方法对湍流谱函数进行近似,推导获得了对流层散射传输损耗与大气折射率结构常数的关系,即L-C模型;开展了对流层散射传播试验,基于WRF(Weather Research and Forecasting)数值模式对试验期间大气折射率结构常数进行预报;基于预报的大气折射率结构常数数据应用L-C模型预测对流层散射传输损耗,并与试验测试损耗值进行对比研究.结果表明,应用L-C模型预测的损耗值与实测值变化趋势吻合较好,均方根误差不超过6dB,并且传输损耗与大气折射率结构常数间的相关系数均大于0.7,表明了对流层散射传输损耗与大气折射率结构常数之间较强的相关性.这种对流层散射与大气折射率结构常数之间的相关性对于对流层散射传输的机理和建模研究都有重要意义.

Based on the incoherent scatter theory of atmospheric turbulence,the turbulence spectrum is approximated by the Taylor method,and the relationship between the tropospheric scattering transmission loss and the atmospheric structure constant of the refractive index is obtained,that is,L-C model.The troposcatter propagation experiment was carried out,and the atmospheric structure constant of the refractive index during the test was predicted based on the numerical weather prediction model of WRF(Weather Research and Forecasting).Based on the forecasted data of the atmospheric structure constant of the refractive index,the L-C model is used to predict the troposcatter transmission loss,and compared with the measured loss.It is shown that the variation tendency of the predicted loss and the measured loss are in good agreement,and the RMS(root mean square)errors are no more than 6dB.On the other hand,the correlation coefficients between the transmission loss and the structure constant of the refractive index are all greater than 0.7.All of these show that there is indeed a strong correlation between troposcatter transmission loss and structure constant of the refractive index,and this correlation is of great value for the investigation of the mechanism and modeling on troposcatter transmission.