Accession Number : AD0439416


Title :   DIRECTIONAL, SPECTRAL, AND STATISTICAL PROPERTIES OF THE UNDER-ICE NOISE IN THE ARCTIC,


Corporate Author : GM DEFENSE RESEARCH LABS SANTA BARBARA CALIF


Personal Author(s) : Greene,C R


Report Date : Mar 1964


Pagination or Media Count : 23


Abstract : Results of the analysis of ambient noise recordings are presented. The average pressure spectrum level observed over the 15-day period was about 5 db over Knudsen's sea state zero extended. As a function of time, the pressure spectrum level correlated significantly with wind speed. There was little difference in ambient noise received by vertical seismometers in thick ice or thin ice. Crosscorrelation of horizontally spaced hydrophones showed that the noise was anisotropic in azimuth, and that the degree of anisotropy was correlated with wind speed delayed by one day. The amplitude probability density function was found to be non-normal by virtue of higher probabilities for high amplitude noise, although this was less for periods of low noise or deep hydrophones than for high noise or shallow hydrophones. (Author)


Descriptors :   *HYDROPHONES , *UNDERWATER SOUND , ARCTIC OCEAN , NOISE , ICE , ARCTIC REGIONS , BACKGROUND , PRESSURE , WIND , CORRELATION TECHNIQUES


Distribution Statement : APPROVED FOR PUBLIC RELEASE