A rolling line source for a seismic sonar

Abstract

This thesis builds on ideas of a seismo-acoustic sonar as a mine detection tool and is part of an ongoing Naval Postgraduate School (NPS) research project. Building on this foundation of research, a source was developed to enable mobility. The previous NPS array [Sheetz] design employed an array of sources, buried in the sediment in a line. This arrangement is somewhat cumbersome for direct application. A practical device should be mobile and create a high source signal similar to the previous NPS array. A rolling cylinder provided the solution. The cylinder houses two shakers, identical to the previous NPS array elements, mounted directly to the cylinder wall. The source for a single buried array element, from the previous NPS array, and a single rolling cylinder, placed on the surface, were shown to provide similar seismic velocity at ten meters range. Using this rolling source, we measured wave speed at 83 m/s by signal correlation methods. Employing two rolling cylinder sources against a buried 1000 lb bomb at five meters range resulted in echo detection with only internal signal analyzer algorithms. The ability to send and receive signals on the go was proven to be attainable with a rolling line source.http://archive.org/details/arollinglinesour109455874Lieutenant, United States Naval ReserveApproved for public release; distribution is unlimited