Accession Number : AD0689742

Title :   SEAMOUNT DETECTION BY CROSS CORRELATION OF REVERBERATION ECHOES.

Descriptive Note : Technical rept.,

Corporate Author : COLUMBIA UNIV DOBBS FERRY N Y HUDSON LABS

Personal Author(s) : Hardy,Wilton A.

Report Date : MAR 1969

Pagination or Media Count : 63

Abstract : A 300-lb TNT explosive charge was used as an acoustic source to excite underwater reverberation in several ocean areas. The echoes returned from ranges of more than 40 miles from the source were primarily due to reflections from prominent slopes of the bathymetry of well-defined seamounts. The signals were analyzed by cross correlation across the members of several shipboard-suspended hydrophone pairs to determine the relative time delays of the signals and hence the azimuthal orientation of the echo arrivals with respect to the hydrophones. The ranges of the echoes were determined from the round-trip travel time of the acoustic signals from the source back to the detecting hydrophones. The results, presented in this paper, show that prominent bathymetric reflectors can be located in the insonified ocean region at ranges up to, and sometimes more than, 300 miles from the source. (Author)

Descriptors :   (*OCEAN BOTTOM TOPOGRAPHY, ECHO RANGING), TNT, UNDERWATER EXPLOSIONS, BATHYTHERMOGRAPH DATA, REFLECTION, HYDROPHONES, UNDERWATER SOUND SIGNALS, AMPLIFIERS, CORRELATION TECHNIQUES, FOURIER ANALYSIS, SOUND TRANSMISSION, UNDERWATER SOUND

Subject Categories : Physical and Dynamic Oceanography
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE