Publications
Analysis of low-mode arrivals at 500 and 1000-km ranges in the North Pacific
Abstract
Experimental measurements of low mode signals in the deep ocean are needed to verify statistical models and to design improved processing algorithms for these signals. Several long-range propagation experiments provided estimates of low mode statistics at ranges between 3 and 5 megameters [Wage et al., J. Acoust. Soc. Am. 117, pp. 1565-1581 (2005)]. The 2004-2005 SPICE experiment included measurements at shorter ranges and a higher frequency than previous experiments. A 40-element vertical line array (VLA) received signals from two broadband sources at ranges of 500 km and 1000 km. Both sources were moored at depths near the sound channel axis, thus they directly excited the lowest modes. The VLA was designed to spatially resolve 20 modes at the center frequency of 250 Hz. In addition to hydrophones the SPICE array included temperature and salinity sensors, which can be used to infer sound speed, and hence modeshapes, at the VLA. This talk describes an analysis of the low mode arrivals in the SPICE data set. The presentation will include a discussion of mode filter design, focusing on how often the filter coefficients need to be updated to avoid problems with environmental mismatch. [Work supported by ONR.]
© 2006 Acoustical Society of America. This abstract may be downloaded for personal use only. Any other use requires the permission of the author and the Acoustical Society of America. The abstract appeared in the Journal of the Acoustical Society of America, vol. 120(5), p. 3021, November, 2006 and may also be found on the JASA website.