Seafloor Scattering in Three Dimensions by Time Domain Finite Differences

摘要

We were unsuccessful at making progress with the 3-D SEM research. As a complementary effort, we have packaged our 2-D TDFD code for distribution through the Ocean Acoustics Library (http://oalib.saic.com/). At a recent workshop on 'Seismoacoustic applications in marine geology &; geophysics' it was recognized that long range acoustic propagation in the ocean is not completely trapped in the SOFAR channel even in very deep water. The evidence comes from 2 disciplines: long-range controlled-source acoustic propagation experiments at frequencies around 75Hz & marine seismology. Under the finding for this TDFD grant we pursued 3 aspects of the long range acoustic propagation problem: (a) observations of SOFAR channel propagation in shadow zones well outside the channel, (b) securing OBS's for the LOAPEX experiment to enable controlled simultaneous observations of signals in the sound channel and on the deep seafloor, & (c) TDFD modeling of long range acoustic propagation.