水下复杂形状目标回声的过渡特性

Transition Characteristics of Echoes from Complex Shape Targets in Water

对水下复杂目标进行多个子目标积木式建模 .利用近场板块元方法研究目标近场、远场的过渡规律 ,并运用了目标相互干涉理论 ,对复杂目标近场回声强度出现的干涉现象进行了物理解释 .获得了频率为 3 k Hz和 5 k Hz的平面波正横入射和斜入射水下复杂目标时 ,回声强度随距离变化的规律 .与简单形状目标相比 ,复杂目标的回声强度随频率和距离的变化更为复杂 .

The near field echo characteristics of the complex shape targets were investigated. The complex shape targets were modeled with several simple shape sub-targets. The near field planar element method was applied for the complex shape targets to calculate the transition characteristics from near field to far field. The interference phenomena of the near field echoes from the complex shape targets was explained by using the sub-targets interference theory. Numerical results of echo strength at frequency 3 kHz and 5 kHz were obtained in the case of the plane wave normal incidence and oblique incidence. By comparison with simple shape targets, the echo strength of the complex targets versus frequency and range is more complex.