From May 2nd to 3rd, Dr. T. C. Yang from the Nat. Sun Yat-Sen University gave two lectures at IOA.
In his first lecture, Dr. Yang introduced a clutter reduction method using Doppler sonar in a harbor environment. Experimental results show that Doppler processing can be used to separate the environmental reverberation from the echoes of the expected target. Doppler detection in the high Doppler space is practically reverberation free.
For the second lecture, Dr. Yang presented the sound intensity fluctuations in the presence of non-linear internal waves. A Mode-coupling-matrix approach is proposed to calculate the sound field due to the activities of solitary internal waves. As the internal wave moves, it changes the interference structure of the sound field. With a fixed-source-receiver system, the velocity of the internal wave can be estimated by the range-frequency spectrum of the sound field. This is a novel idea to get environmental parameters through acoustic inversion.
Dr. Yang’s researches cover a wide field of underwater acoustics. With many contents the audiences interested in, both of his lectures were followed by heated discussions.
Dr. T. C. Yang is a national science counsel chair professor at the Inst. of Applied Marine Physics and Undersea Technology, Nat. Sun Yat-Sen Univ. Kaohsiung, Taiwan. He spent 32 years working at and has recently retired from the Naval Research Laboratory, Washington, DC.His current research focuses on environmental impacts on underwater acoustic communications and networking, exploiting the channel physics to characterize and improve performance, and environmental acoustic sensing and signal processing issues aimed at improving the effectiveness of distributed networked sensing. In earlier years, he pioneered matched mode processing for a vertical line array, and matched-beam processing for a horizontal line array. Other areas of research included geoacoustic inversions, waveguide invariants, effects of internal waves on sound propagation in shallow water, Arctic acoustics, etc. He is a fellow of the Acoustical Society of America.
Dr. T. C. Yang is lecturing