Twenty-Five Sound Propagation Tests on the Continental Shelf between Long Island, New York and Cape Canaveral, Florida.

摘要

In 1954 and in 1955 sound propagation measurements were made combined with seismic refraction profiles, bathythermograph profiles, and continuous echo soundings over more than 42 different tracks that lie partly or wholly within the 200-meter depth contour of the U.S. east coast continental shelf between latitude 26 N and 40 N. Spectrum levels of propagation loss (PL) have been computed for octave frequency bands 50 to 100 Hz, 200 to 400 Hz, 800 to 1600 Hz, and 2400 to 4800 Hz. In general PL is greatest for the 50 to 100 cps band. PL for the other bands tends to be high if that for the 50 to 100 band is high. At ranges much less than 10 km PL is commonly frequency independent. At ranges of 10 km or greater for the 50-100 Hz band PL becomes greater than the higher bands by amounts varying from 3 dB to more than 20 dB in 18 out of 32 sound propagation profiles used in this study. 17 of the 32 also displayed as optimum frequency band either the 200-400 Hz or the 800-1600 Hz bands employed in the analysis. The remaining 12 or 13 profiles either do not display frequency dependence among the 4 bands used, or they display high-pass, low-pass, or band rejection behavior.