Humminbird Side Imaging Forums
Other Interest => DIY - Side Scan Sonar and towfish => Topic started by: abraquelebout on June 11, 2011, 07:07:03 PM
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2 days scaning in salt wather over 30 m, towfish with 60 m cable
i thing that scaning in salt water is possible in 455 khz but difficult in 800 because in 800 a little wave or interference make a very bad picture, problem with current to take the target in 8 or 10 meter range
i join sample[attachment=1] in 455 khz, good picture
[attachment=2]
in 800 khz there's more noise (wave, motor...) the picture is not good
800 khz is very nice in river
i hope that a double ducer in 455 khz is a good solution in salt water...
as anybody get experience in this type of search
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picture in 455[attachment=1]
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Hi Abra,
Interesting to see your experiences. I seems as if waves is the main issue when scanning at sea. I mostly scan in lakes and in the Baltic where conditions are rather easy to cope with (some days conditions are terrible, though..).
When I see your results I recall having seen systems where the towfish is almost boyant and towed 10 - 20 m behind a heavy depressor. Waves which affect the boat will affect the depressor, but the effect on the towfish will be small. Perhaps this would enhance the results more than a doubleducer would?
Regards,
Rickard
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ok rickard
i think making a eavy profiled lest 15 m behind towfish (5 kg seem's a good solution)
towfish 5,7 kg an 5 kg lest i hope that it may be working...
i test it and publy result...
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Abra,
Here you have one among many examples of how this can be arranged.
http://www.openseas.com/stabs-tow.htm (http://www.openseas.com/stabs-tow.htm)
They say a neutrally boyant towfish is ideal.
Rickard