声速剖面对不同深度声源定位的影响

Influences of sound speed profile on the source localization of different depths

在对一次试验数据进行匹配场定位处理时发现,选取声速剖面有轻微失配的情形下,水面弱声源显现,水下强声源反而消失.基于该现象研究了声速剖面失配对不同深度声源定位的影响.首先通过仿真试验排除海上试验中不确定因素的影响,进一步得出深处声源定位受声速剖面失配影响较大的结论,并针对夏季负跃层情形进行跃层深度失配的仿真,初步得出在跃层下边界以下10 m附近处的声源对声速剖面失配最敏感.最后从简正波的角度进行理论分析,分两点对这一现象进行了合理解释.

It is found in the data processing of matched filed source localization experiment that in the case of the slight mismatch of sound speed profile, the louder source below disappears while the weaker source above comes out. Based on the experimental phenomenon, the influences of the sound speed profile on the source localization of different depths are investigated. Firstly, the simulation is conducted in order to extract the influence of the uncertain factors in the sea test, from which it is further concluded that the deeper source is greatly affected. Then another simulation about the mismatch of the depth of the thermocline is conducted in the typical shallow-water negative gradient environment, from which a preliminary conclusion is drawn that the most sensitive depth to the mismatch of the sound speed profile is around 10 meters below the lower boundary thermocline. Finally, this pheonomenon is reasonably explained through a theoretical analysis from two aspects of the normal mode theory.