地质B超中聚束波的振幅与频率特征研究

地质B超是基于医学上的B超思想,采用相控超声激发方式,使用多个波源,通过相控,使波在地下探测点聚焦,以增强能量,并采用连续扫描的观测方式成像.本文根据这种思想,分析了聚焦波的振幅特性和频率特性,由理论分析可知,聚束波相当于一个线性系统,具有低通滤波效应,当单波相位差较小时,聚束波能量显著增强,高频成分损失不大.

THE AMPLITUDE AND FREQUENCY CHARACTERISTICS OF THE WAVE BEAM BASED ON THE IDEA OF GEOLOGIC B-ULTRASONIC

B--ultrasonic in Geology is based on the idea of B--ultrasonic in medicine, and adopts phase control to explode. This method uses a series of wave sources, and focuses the waves from different sources to produce wave beam to swell the wave energy at the point underground by phase control. Meanwhile this method adopts the mode of sequence scan to image. Based on this theory, this paper analyses the amplitude and frequency characteristics of the wave beam, and points out that the wave beam is almost equal to a linearity system with low frequency filter. Once the phase offset is small, the energy of the wave beam is big, and the attenuation of high frequency of wave is small.