Accession Number : ADA311204

Title :   Backscatter Data Acquisition for Hydrosweep-DS Aboard R.V. Ewing.

Descriptive Note : Final rept. 1 May 92-31 Dec 93,

Corporate Author : TRUSTEES OF COLUMBIA UNIV NEW YORK

Personal Author(s) : Chayes, Dale N.

PDF Url : ADA311204

Report Date : 04 SEP 1996

Pagination or Media Count : 6

Abstract : This work focuses on continuing to develop an effective interface to capture and log the raw hydrophone and supporting data. The objectives are to design and implement a data acquisition scheme that preserves calibrated base banded quadrature samples of the output of individual hydrophone staves and the required supporting data for use with modern signal processing and swath mapping techniques. The initial approach consisted of tapping the pre-existing digital output of each hydrophone channel, performing a base banding operation and retaining enough samples to provide about twice the Nyquist rate for later processing. Due to the limited dynamic range of the existing converters, this design was not suitable. A prototype which acquired raw analog data at the output of the existing preamplifier using Crystal Semiconductor (CS-5336) dual channel, 16-bit delta sigma converters with a high quality differential amplifier front end was built and tested briefly, but a full system was not built due to lack of resources.

Descriptors :   *BEAM FORMING, *HYDROPHONES, SIGNAL PROCESSING, DIGITAL SYSTEMS, PREAMPLIFIERS, SEMICONDUCTOR DEVICES, CRYSTALS, BACKSCATTERING, CALIBRATION, DUAL CHANNEL, ANALOG SIGNALS, DYNAMIC RANGE.

Subject Categories : Acoustic Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE