基于半分析声线模型计算顺风环境对大气声传遍的影响

本文建立了顺风条件下大气声传播的声线半分析模型，等效声速为对数声速剖面。本模型采用分析迭代的方法，通过积分得到声线轨迹的解析解，并对声线进行分组，每组都由四条声线组成，从而计算出远场声压的超额衰减。较其他方法而言，该模型计算时间较短，最终得到了考虑地面反射和大气折射影响的超额衰减频率响应曲线。

The computation of effects on the atmosphere sound propagation produced by the downwind based on the semianalytical ray model

The semi analytical ray model of the atmosphere sound propagation under the downwind condition has been established in this paper, the equivalent sound profile is replaced by the power profile of the sound speed. The analysis and iterative method have been employed in this model to solve the analytic solution of the ray tracks through integral, which takes the advantage of the fact that ray paths are ordered in groups of four, therefore the far field excess attenuation can be calculated. Compared with other methods, and this model requires a very small computation time. Ground reflections and atmosphere refractions are taken into account to evaluate the excess attenuation and other solutions in this model. Finaly, the curve of excess attenuation versus frequency have been plotted.