Edgetech 3200-XS User Manual page 74

B-2
APPENDIX B:
6.
How does the 3200-XS Sub-Bottom Profiling System interface to a navigation device?
The COM 1-NAV or the COM3 RS-232 serial port can be used to interface with a
navigation device.
7.
How do the environmental conditions affect the performance of the 3200-XS
Sub-Bottom Profiling System?
There are several environmental factors that affect performance:
Geological conditions—The 3200-XS Sub-Bottom Profiling System operating
parameters and listed specifications are greatly affected by the geologic conditions
that the acoustic energy transmitted from the tow vehicle encounters. A very dense
geologic interface, such as rock, coral, sand, stone, shell beds, and so on, will limit the
sound penetration into the sub-bottom. This limitation is caused by the density
interface reflecting most, if not all, normal incidence acoustic energy back to the
receiving hydrophone which results in little penetration.
Air/water interface— The air/water interface reflects 99.8 percent of the acoustic
energy it receives. Therefore when air or gas is encountered in the water column or in
the sub-bottom, almost all of the transmitted acoustic energy will be reflected back to
the tow vehicle resulting in little or no penetration into the seabed.
Survey vessel's wake—The ship's wake is a very turbulent area that is located
immediately behind the ship. When towing the tow vehicle in or near this wake, the
transmitted acoustic energy encounters highly charged aerated water caused by the
cavitation of the ship's propellers. If the tow vehicle is operated in this area, most of the
acoustic energy from the aerated water is reflected back to its source, similar to that
exhibited by an air/water interface. The tow vehicle is designed to operate in a
horizontal position relative to the sea floor. The turbulence encountered when
operated in or near the ship's wake will cause instability in the tow vehicle and reduce
the effectiveness of the output energy in penetrating the sub-bottom sediments.
Noise—Operating other nearby acoustic devices at frequencies within the operating
frequency bandwidth of the 3200-XS Sub-Bottom Profiling System can result in data
distortion.
Survey vessel's motion—The tow vehicle is designed to tow in a stable horizontal
plane. Excessive ship motion can cause instability in the tow vehicle attitude resulting
in reduced performance. Rough sea conditions, sharp turns of the ship and any similar
external induced motions on the tow vehicle will have a similar effect on the system
operation.
3200-XS Sub-Bottom Profiling System User's Manual
Frequently Asked Questions
Doc. No. 990-0000026-1000, Rev. 2.3