Thread: Sonar Quiz #24

IF I UNDERSTAND U RIGHT RICKIE, I THINK THE ROPE TO DRIFT SOCK IS STAYING IN SI BEAM ALL TIME

If I am figuring it correctly isn't it 30" in diameter? Maybe that is something else to address, how big is the actual object appearing on the snapshot?

Originally Posted by vic n

I think that as Spearfish III is trolling, he is making course corrections, which causes the wind sock to drift in and out

Originally Posted by Redge

Because the sock is moving left to right? Ie steering corrections?

As we don't really know how Spearfish III trolls for trout ... We can't be sure if the sock is moving away from the xducer (maybe sinking with no float)... or the xducer is moving away from the sock (as the boat turns)...

We can be sure that the distance between the xducer and the sock is changing ...

Rickie

Okay....now let's talk about the shadow. I was over on BBC and saw virtually the same shadow on another SI shot

I don't have a clue on the shadow! Looking forward to learning something new.

"Dark lines" aka "Ghost Lines" aka "Washboard lines" anomalies show up in side scanning images most commonly in examples of side scan images captured while using an xducer that has both "side pointing" SI piezoes and a "down pointing" DI piezo ...

LSS 1

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LSS 2 (not as prominent but still there) ...

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Onix

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Garmin


Overlapping slice beams can create an effect similar to this beam form example which end up showing in the SI image as the dark lines ...



Rickie

Thanks Rickie!!

There is another SI anomaly that shows up sometimes as a matching left and right SI dark line called the "null sector" of the beam form ... But it's usually less prominent and not necessarily in an xducer with both "side pointing" SI piezoes and a "down pointing" DI piezo ...



Rickie