Pekeris波导中垂直发射阵的阵增益快速估计

为了利用单换能器的声强级估计垂直发射阵的声强级,研究了Pekeris波导中快速估计发射阵增益的方法。首先,基于等效深度简正波理论,计算了Pekeris波导中垂直发射阵的平均声强,进而得到用模态阶数求和表示的发射阵增益的表达式。然后对模态阶数用积分代替求和,并对引入的误差进行修,得到3/2次方衰减场区发射阵增益的快速估计表达式;有效声影区声场由于只剩1阶简正模态,可直接简化得到发射阵增益的快速估计表达式,在海底参数未知时可用海深近似代替等效深度来估计有效声影区的发射阵增益。计算机仿真和海上实验得到的阵增益快速估计误差均小于1 dB,验证了快速估计方法的有效性,这一发射阵增益快速估计方法可以为工程应用提供参考。 

Fast estimation of array gain of vertical transmit array in Pekeris waveguide

In order to estimate the sound intensity level of Vertical Transmit Array (VTA) from that of single transducer,a fast estimation method of Transmit Array Gain (TAG) in Pekeris waveguide is studied.At first,the average sound intensity of VTA is calculated on the basis of normal mode theory with effective depth,and the TAG expressed by the summation of modes is derived.Then by using integral instead of summation of modes order,the fast estimation expression of TAG in 3/2 power field is derived after error correction.Because only the first mode exists in Effective Shadow Zone (ESZ),the fast estimation expression of TAG in ESZ is derived by directly simplifying the former expression.The effective depth can be approximately replaced by the depth of water when the seafloor geoacoustic parameters are unknown.All of the fast estimation errors of computer simulations and experiment in shallow water are less than 1 dB,which can verify the validity of the fast estimation method.This fast estimation method of TAG can provide references for practical application.