充液球的聚焦增益及其频率特性与脉宽壳厚的关系

充液聚焦球形反射体（简称充液球）是一种理想的标准反射体。它有几何尺寸小、目标强度大、频率特性好、方向性均匀、成本低、海上布设方便等优点。常用于水声学测量和水声设备的检验,校准及有关人员训练之用。
在文献^[1]中研究了充液球的目标强度,聚焦增益与频率、方位、折射率的关系,着重研究在温度变化的情况下提高聚焦增益的问题。国外对充液球的目标强度作过研究^[2-4],但这些工作都是在短脉冲情况下做的。而实际工作中常常使用长脉冲,因此仅有短脉冲结果是很不够的,所以本文着重研究了长脉冲情况下的聚焦增益及其频率特性。

RELATIONSHIP BETWEEN FOCUSING GAIN OF FOCUSED LIQUID-FILLED SPHERE AND ITS PROPERTY OF FREQUENCY WITH WIDTH OF PULSE AND WALL THICK OF SPHERE

In this paper, relationship between focusing gain of focused liquid-filled sphere vs frequency in different width of pulse was studied. Formula of outstanding focusing gain difference was deduced. The change of focusing gain of long pulse vs frequency is described with this formula. Corresponding experiment was made. Its results explain that the change of focusing gain of short pulse with frequency is small. Frequency property of focusing gain of long pulse relate to size of focusing gain of short pulse. Experimental results are in good agreement with theoretical results. In order to obtain big target strength and better frequency property must great as much as possible focusing gain of short pulse.
Experiment of focusing gain vs wall thick of sphere was made too. Experimental results explain that wall thick of sphere clearly effects focusing gain of focused liquid-filled sphere and its frequency property.