Accession Number : ADA327339

Title :   An Investigation of the Sources and Characteristics of the Noise Component in SeaMarc II Echo Signals.

Descriptive Note : Final rept.,

Corporate Author : HAWAII UNIV HONOLULU SCHOOL OF OCEAN AND EARTH SCIENCE AND TECHNOLOGY

Personal Author(s) : Zisk, Stanley

PDF Url : ADA327339

Report Date : 28 JAN 1996

Pagination or Media Count : 5

Abstract : As is well known, the SeaMarc II towfish system was lost at sea during a scientific survey cruise in the Southern Ocean near the beginning of this project. Work was immediately begun on the design and construction of a replacement mapping system to be called HAWAII MR1. The signal processing for this system was designed based on the crude and incomplete information obtained earlier from one short series of noise measurements that had been made on SeaMarc II with experimental modifications. In the new MR1 system, the recorded signal consisted of digital, complex samples of the acoustic echo (i.e. in-phase and quadrature components, referenced to transmitter sinusoidal waveform). The entire duration of the echo signal was recorded, including the entire water column reverberation and the subsequent seafloor echoes, usually out to 70 - 80 degrees incidence angle.

Descriptors :   *ECHOES, *REVERBERATION, *ACOUSTIC RECORDING SYSTEMS, SIGNAL PROCESSING, SIGNAL TO NOISE RATIO, SHALLOW WATER, BATHYMETRY, REPLACEMENT, MAPPING, NOISE, DEEP WATER, OCEAN BOTTOM, ACOUSTIC IMPEDANCE, DIGITAL RECORDING SYSTEMS, DEEP SCATTERING LAYERS.

Subject Categories : Physical and Dynamic Oceanography
      Recording and Playback Devices
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE