海水温盐垂直结构的声反射回波模型及应用

The acoustic echo model of vertical structure of seawater temperature and salinity and its application

基于等时厚分层假设,建立海水温盐垂直结构的声反射回波计算模型,并对实际海洋层结状态的声反射回波特征进行了详细分析。结果表明:声反射回波幅度变化的位置和海水介质温盐梯度变化不为零的位置一致,回波幅度和梯度变化幅度成正比;而回波的极性反映了梯度变化的趋势。将该模型用于反演试验,能够直接得到海水温、盐垂直结构反演结果,效果较好,克服了以往反演算法中不便于密度和声速分离的缺点。

Based on assumptions of layered media with equal time layer thickness, a model which can be used to com- pute the acoustic reflected echo of seawater thermohaline profile is built. The characteristics of the reflected echo of the seawater profile are analyzed in detail. The results are summarized as follows. The amplitude of the reflected echo changes where there is a variation in the thermohaline gradient. The amplitude of reflected echo is proportion- al to the change range of thermohaline gradient, and the polarity of the echo reflects the change trend of the gradi- ent. The model is used in inversion experimentation of the vertical structure of ocean temperature and salinity. The model is verified by the measurements and overcomes the shortcomings of the previous inversion algorithm which does not facilitate the separation of density and velocity of sound.