Calibrating a 90-kHz Multibeam Sonar

reportActive / Technical Report | Accession Number: ADA497551 | Open PDF

Abstract:

Quantitative use of multibeam sonar requires calibration. Protocols for calibrating multibeam sonar in an absolute sense by means of a standard target are being developed. These protocols are illustrated for the Simrad SM2000 Multibeam Echo Sounder, with 90-kHz operating frequency and 300 beams over a 90-deg sector -45 deg, each of nominal beamwidth 1.5x1.5 deg. In a sea well on Iselin Dock at the Woods Hole Oceanographic Institution, directional characteristics of the sonar were measured at the farfield range of 23 m in a sea well. At the large freshwater indoor tank at the University of New Hampshire, similar characteristics of directivity were measured at the nearfield range of 11.7 m. Beamforming was accomplished by digital signal processing. Beam patterns are presented and compared at both ranges. In addition, measurements of the on-axis response were made for each available time-varied-gain function, enabling linearity and dynamic range to be assessed.

Author(s):
Chu, Dezhang ; Foote, Kenneth G. ; Hufnagle, Jr., Lawrence C. ; Hammar, Terence R. ; Libertore, Stephen P. ; Baldwin, Kenneth C. ; Mayer, Larry A. ; Mcleod, Andrew
Author Organization(s):
WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
Descriptive Note:
Conference paper
Supplementary Note:
See also ADM002146. Presented at the Oceans 2003 MTS/IEEE Conference held in San Diego, California on 22-26 Sep 2003. Published in the Oceans 2003 MTS/IEEE Conference Proceedings, p1633-1636, Sep 2003. U.S. Government or Federal Purpose Rights License, The original document contains color images.
Pagination:
0005

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release; Distribution Is Unlimited.

RECORD

Collection: TR
Identifying Numbers
Contract/Grant Number(s):
OCE-0002664
Monitor Series:
NSF
 Subject Terms
Joint Capability Areas:
JCA_6_Net Centric; JCA_6.1_Information Transport; JCA_8_Building Partnerships
Communities of Interest:
No COI(s) Identified
Descriptor(s):
*CALIBRATION, *MULTIPLE BEAMS(RADIATION), *SONAR, FRESH WATER, BEAM FORMING, RADIATION PATTERNS, DYNAMIC RANGE, NEAR FIELD, FAR FIELD, DIGITAL SYSTEMS, SIGNAL PROCESSING
Field(s)/Group(s):
Test Facilities, Equipment and Methods, Acoustic Detection and Detectors
Report Date:
2003 Sep 01
Creation Date:
2009 May 13