Simplify Side-Imaging!

This is how i interpret what i am seeing on Side-Imaging Sonar. I do not have all the answers and there are still many questions I have myself. I tell you what I believe side-imaging is showing and try to show actual footage of why I believe what I believe. This video is 100% my opinion.

[tavaftw]

I really appreciate your efforts, and I'm literally checking your new videos daily. Regarding the mark on the 4 ft pass, it's actually the buoy, similar to the pontoon you scanned at the docks. Also, you should have noticed a mark on the 20-foot mark for the bottle, which is positioned 20 feet from the transducer. Think of the fish finder and transducer in this way: any mark represents the combined signal reflected from the same distance to the transducer. The screen simply registers the distances of these signals based on the time it takes for them to be transmitted and received.
Imagine a mark on the 20-foot mark on your screen. Picture a 20-foot circle centered at the transducer left element; any object on the perimeter of that circle is displayed on the left side of the screen at that 20-foot . This is why we consistently get the strongest signal at the vertical bottom area. Try drawing circles around the transducer at 1-foot intervals and then mapping to the screen, and you'll understand what I mean.

[boydlittou]

If anyone knows how they really work its the manufacturer. But they dont tell or give us the detailed view or info. Which they should for what we pay for these units. I seem to remember reading they do use side and down both to create the image. I have also read that the water column is downscan which makes sense because its exactly what you see on downscan. I also believe the side andcdown beams overlap some. We need a clear video from the manufacturer's and its past time they provide it.

[macEboy]

Wow is all I got wow.
Thank you so much. This helps me more than any other explanation I've seen.

[murphysforms]

Great (OPINION) Mr.Squirrel. Helps clear up my thinking. Thank You

[sprinter]

Interesting topic. I love that you did this experiment. Having watched here are my thoughts: I have my doubts the sidescan and downscan are stitched together to make the image because we all know that live sonar uses multiple beams and the stitching is pretty obvious. I think the 3d image are drawn on a 2d chart and the distance an object is from the transducer is calculated by the computer and it draws it on the graph. This is done without depth as a factor. So the water bottles were shown in the water column, which they were and 4 feet away, which they were. Again without depth as a factor. If depth would have been a factor then it would have shown the bottles a little more than 20 feet away (the hypotenuse of a right triangle).

[wantboutdoors]

I appreciate the explanation brother..gives me a clearer picture of what to look for

[michaeltorpea]

The area under the boat that isn’t covered by the side imaging beam is very small (approximately 5 degrees to either side of vertical). The conventional down-looking sonar that is built into the side imaging transducer covers the areas below the boat and the Side Imaging Units allow you to view a split screen that will show both 2D coverage and Side Imaging sonar simultaneously.

[wmcknigify]

Thank you for your video, I also struggle with these things trying to figure what's what. My 2 cents worth for what's it worth -
The transducer really only knows distance, it doesn't know anything about angles or depth. Remember how these things work, they send out a ping and wait on it to come back, the time it takes for that return tells it the distance, give or take. There is no way to know depth based on that data. This is why your distance verifications are pretty accurate.

[Pilot]

Great experiment on the lake!😁👍👍. Thankyou Squirrel

[longpointfishmaster]

i like the experiment. i thought of doing something similar.
it seems like your chart is only showing distance away and is calculated out to make it easier for people to figure out. just simple programing. says object is 100 ft to the left move boat 100ft to the left and and you will be on top of it.
. so its some thing is 100 ft to the left. its 100 ft to the left and straight down.

maybe try the way point feature then move to weigh point and see where u end up,


but lets throw a curve ball into the mix.

you ever see the same item in the image on both sides at the edge of the black and orange. when its shows a mirror image on both sides. that means it right under the boat.

[cuttlefishpie]

How about finding a big rock underwater with traditional sonar and waypointing it. Then pregressively drive your boat parallel to it at incremental or decreasing distances from it with side scan until it just shows up right at the interface between the dark area and light area? That will help you ‘calibrate’ your mental image of what is going on I think??!!

[officialWWM]

This is an awesome video. Thanks for taking the time to make it!

[thelizardshaman]

Great video. I've been so confused about this topic too. Everything made clear sense except for how you were able to see that bottle 4ft to the left 20ft down. I don't think it's down imaging in conjugation with side imaging because you would see the bottom and structure in that black area. I am baffled as to how that showed up. My theory is that the return you got was the rope going down to the bottles. That's why that mark looked so linear. That should be the only possible explanation right? Please do some more testing on getting returns inside that "dead zone" triangle area.

What's funny to me is that all the manufacturers videos are incorrect in saying the black area is the water column directly UNDER your boat. Which is mind blowing. How could they all have that wrong? But my evidence and yours points to the "dead zone" triangle being what is truly shown, and if you do get a return in the black area, it has to be above the 45° line.

[simtsoz]

More confused now than I was before. 😂

[jimbugs]

subscribed even though the Clemson hat go dawgs

[mikesampson]

Thank u 🐿️. For a awesome video of side views keep up the great videos. Sampy

[JimmyGFishing]

Slant range, horizontal range, height of the concrete column, depth, speed... so many factors you seem to forget. Slant/Horizontal tells the truth.

[briancorrell]

Thank you for doing these experiments. I've been striking out when trying to find shad with the net. I see them on screen in the water column and throw directly behind my kayak and come up your answers here may be what I was missing.

However, I have a question about that bait ball that was shown in your video at the 6:00 minute mark. That bait ball appears on both left and right side, so wouldn't that indicate that it is directly below the transducer? That would indicate that the paper method and folding to get a vertical water column would be correct. But I also see your proof that the bottles suspended 20 ft down but only 4 feet to the left of the transducer. I'm still missing something. KEEP AT IT great experiments!

[chriss]

I love my site scan sonar I bought this technology when it 1st came out it was out for a week at bass pro when I purchased it I have the same model I purchased 20 years ago almost actually 20 years ago a little bit more I think it's the greatest thing since slice bread life scope is great but I really love my side scan

[Christian_Johansson]

How come you, if you run right over it, can see a small sunken boat on the bottom in say 30ft and you can see it on both sides of the sidescan? I can't see that your theory is right either then, although I agree that what they normally teach that sidescan looks like is inaccurate too.