深海甚低频水声与地震波场的联合探测试验

A deep-sea, self-contained, three-component seismic wave sensing system is designed in this work to provide the feasibility basis of combined fuze technology of very low frequency (VLF) acoustic and seismic wavefields. A real ship target sensing test is conducted in the South China Sea (depth:1825 m) with a deep-sea bottom-sitting subsurface buoy sensing system. The test data of the acoustic field and seismic wave field of a moving ship are obtained by setting a survey line. Comparative analysis of these data indicates that the contributions to target detection by the acoustic and seismic wave fields have similarities and differences. The underwater acoustic field is more dominant because of its abundant periodical narrow-band information, while the seismic wave field is superior to the acoustic field in terms of the detection of near field pass of target; there are even some unique spectral lines that cannot be found in the acoustic field. The real ship noise envelope spectrum analysis of three-component seismic wave also indicates that it has an advantage in sensing the key characteristics of propeller shaft frequency and blade frequency. Thus, the combined analysis of ship VLF acoustic field and seismic wave field has a critical role in the target detection, mine sweeping resistance, decoy resistance, and so on, of the underwater armament. This is a feasible and necessary component of developing deep-sea VLF combined fuze technology.