High-resolution deepwater survey sonar

Conference · Tue May 01 04:00:00 EDT 1984 · Proc., Annu. Offshore Technol. Conf.; (United States)

OSTI ID:6457800

Robinson, G R

As survey requirements moved into water depths greater than 2.500 meters, new technology was required to obtain high resolution geophysical data along precise grid lines. This paper discusses a unique bottom referenced tow system that provides 100 kHz side scan and 3.5 7.0 kHz subbottom sonars; multiplexed over an 8.500 meter single coax tow cable. This design provides a stable towing platform that maintains a constant optimum height over the sea floor which requires minimum cable length alterations that affect the tow fish causing imperfections in the data. This system is meant to provide high quality, distortion-free mosiacs with uniform bottom and sub-bottom features recorded at a constant tow speed and height above the sea floor. Because the towing concept is bottom referenced, the topographic features are lost as the tow fish flies over a high relief area at a constant height off the sea floor. With enhanced electronic techniques, combined with a depth sensor in the fish, the topographic detail of the sea floor is recorded on the sub-bottom record; thus, the survey package provides the complete high resolution record of the true sea floor and sub-bottom features with resolution and quality never achieved before. Another important facet of this system is positioning of the tow fish. With 8.500 meters of cable out, it is imperative for record correlation to know where the tow fish is. A precise ultra-short baseline positioning system integrated with the tow fish telemeters the tow fish position back to the vessel. The position is then correlated to the vessel navigation system to allow position plotting along the survey grid.

• Research Organization: EDO Corp.
• OSTI ID: 6457800
• Report Number(s): CONF-8405208-
• Conference Information: Journal Name: Proc., Annu. Offshore Technol. Conf.; (United States) Journal Volume: 2
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
423000* -- Engineering-- Marine Engineering-- (1980-)
58 GEOSCIENCES
580500 -- Oceanography-- (1980-1989)
CABLES
COAXIAL CABLES
CONDUCTOR DEVICES
DEPTH
DEPTH 6-9 KM
DESIGN
DIMENSIONS
ELECTRIC CABLES
ELECTRICAL EQUIPMENT
ELECTRONIC EQUIPMENT
EQUIPMENT
FREQUENCY RANGE
GEOPHYSICAL SURVEYS
HEIGHT
KHZ RANGE
KHZ RANGE 01-100
LENGTH
MARINE SURVEYS
MEASURING INSTRUMENTS
NAVIGATIONAL INSTRUMENTS
OFFSHORE PLATFORMS
POSITIONING
RANGE FINDERS
RESOLUTION
SEA BED
SONAR
SURVEYS
TOPOGRAPHY
VELOCITY