时间：2013年7月3日14:30

讲座人：姜龙玉

地点：海韵行政楼C505

题目：Separation and detection raypaths in a shallow-water waveguide

摘要：As the studies on shallow-water acoustics became an active field again, this presentation focuses on studying the separation and detection of raypaths in the context of shallow-water ocean acoustic tomography. As a first step of our work, we have given a brief review on the existing array processing techniques in underwater acoustics so as to find the difficulty still faced by this type of methods. Consequently,  we made a conclusion that it is still necessary to improve the separation resolution in order to provide more useful information for the inverse step of ocean acoustic tomography. Thus, a survey on high-resolution method are provided to discover the technique which can be extended to separate the raypaths in our application background. Finally, we proposed a high-resolution method called smoothing-MUSICAL (MUSIC Active Large), which combines the spatial-frequency smoothing with MUSICAL algorithm, for efficient separation of coherent or fully correlated raypaths. However, this method is based on the prior knowledge of the number of raypaths. Thus, we introduce an exponential fitting test (EFT) using short-length samples to determine the number of raypaths. These two methods are both applied to synthetic data and real data acquired in a tank at small scale. Their performances are compared with the relevant conventional methods respectively.

讲座人简介：姜龙玉，法国格勒诺布尔综合理工工学博士，近期主要研究方向为：多维信号处理快速算法，多维源分离，多维源定位，海洋声层析术等。提出了多维离散Hartley变换快速算法，smoothing-MUSICAL等算法，其中2维分裂基 2／8－Hartley变换快速算法仍为该领域国际上综合性能最优的算法。博士学位论文获得了专家评审人的高度评价：“论文综述文献翔实，言简意赅，深入浅出，提出的算法，解决了阵列处理技术的难点，推动了技术的进步，作者已经成为阵列处理领域的专家。”以第一作者身份，在IEEE trans on circuits and systems I等国际知名学术期刊或会议发表论文多篇。为The Journal of the American Acoustical Society: Express letter等知名学术期刊的审稿人。