一种新型的低频高分辨率水声成像方法研究

项目名称： 一种新型的低频高分辨率水声成像方法研究

项目编号： No.61471353

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 何先忠

作者单位： 中国科学院声学研究所

项目金额： 83万元

中文摘要： 本申请创造性地提出了一种新型的低频高分辨率水声成像方法，采用低频信号在水中传播以减少声波的传播损失，用高频泵波将低频回波信号变换成高频回波信号，用高频换能器阵接收高频回波信号，从而实现在同样阵长条件下相对于低频回波信号大幅度地提高接收波束的角度分辨率。为了验证该成像方法的可行性，本研究项目提出采用20～30kHz的线性调频波作为发射信号，用475kHz的单频信号作为泵波将低频回波信号变换成495～505kHz线性调频高频和频波信号，用高频换能器阵接收该高频和频波信号，从而实现高分辨率成像。根据上述方法和参数搭建一套低频高分辨率成像装置,通过湖、海试的方式实地验证在浑浊水中高分辨率探测的有效性和探测海底掩埋物的能力。本研究项目提出了两种低频声场变换成高频声场的方法，并对声－电－声变换提高声场的转换效率进行了探讨。

中文关键词： 水声成像；高分辨率；泵波；非线性调制

英文摘要： This application is a creative way of a novel low-frequency high-resolution underwater acoustic imaging method, using low-frequency signals in the water to reduce the loss of sound wave propagation, changing low frequency echo signal into high frequency echo signal by high-frequency pump wave. So the same length of the array under conditions to improve significantly the reception beam angle resolution of the low-frequency echo signal. In order to verify the feasibility of the imaging method, this research project uses 20～30kHz chirp wave transmitter signal as transmitted signal, uses 475kHz with a single-frequency signal as a pump wave echo signal to change low-frequency signal into 495～505kHz high-frequency and LFM wave signal, receiving the high-frequency sum frequency-wave signal by high-frequency transducer, so achieves high-resolution imaging. According to the method and frequency parameters to build a high-resolution imaging appraratus, by the field-proven way of lake and sea trials in the muddy water, the ability to detect high-resolution seabed effectiveness and explore buried objects. This research project proposes two methods that a low-frequency sound field is converted into a high-frequency field, and sound-electric-acoustic sound field transform improves the conversion efficiency were discussed.

英文关键词： underwater acoustic imaging;high resolution;pump wave;nonlinear modulation