中文摘要：

基于太湖实测散射系数数据估算水下平均散射次数，结合Hydrolight软件模拟水下平均余弦，对二者的相关关系进行分析；根据单个样点、各个水层求算的水下平均余弦经验模型。确定水下平均余弦估算的最佳模式为二次方程，利用二次方程的二次项、一次项和常数项系数与平均散射次数的高度相关性，建立了利用平均散射次数估算二次方程系数的模型，从而建立了利用平均散射次数计算水下平均余弦的经验模型。模型检验表明：0．6m深度平均误差不高于1．712％，0．9m深度平均误差不高于1．982％．1．2m深度平均误差不高于2．05％，1．5m深度平均误差不高于4．22％，4个深度总的平均误差不高于2．491％。

英文摘要：

Base on the average scattering times that calculate through the measured data and the mean cosine value from the HYDROLIGHT simulation, the correlativity between them was analyzed; Secondly, the mean cosine calculation model at each depth of single example point was sought, and the best confirmed model for estimating the mean cosine is the quadratic equation. Ulteriorly, utilizing the high correlation between the average scattering times and the quadratic equation coefficient to build the model that using the average scattering times to calculate the quadratic equation coefficient, consequently establish the estimate model computing the mean cosine from the average scattering times. The proof-test of the model indicates that the average error at 0. 6m depth is smaller than 1. 712%, at 0.9m depth is smaller than 1. 982%, at 1.2m depth is smaller than 2.05%, at 1.5m depth is smaller than 4.22%, and the total average error at four depths is smaller than 2. 491%.