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Took these with the Touch 7. White bass with crappie and smalllies mixed in. Still fine tuning, and I can not figure out interpreting side imaging to save my soul.
http://i49.photobucket.com/albums/f2...psc38a211d.png
http://i49.photobucket.com/albums/f2...psc4f20159.png
http://i49.photobucket.com/albums/f2...psbe35e2ea.png
http://i49.photobucket.com/albums/f2...psb7df9f88.png
Next time slide the info on the right side off, get a full screen
Yeah I was trying to find them with side scan, but struggled and switched to downscan. Got these instead. Spotlocked over the top and it was game on.
Good pics,you must have been going slow,now show us your si in action
zummy...are you having trouble picking out fish and structure on the SI image...or are you having trouble visualizing how that SI image actually lays under the boat...??
Here's a short video I made that shows how the SI processor morphs the 3 dimensional underwater world into the 2 dimensional SI image...
http://youtu.be/gsS-Lgg4HD0
Rickie
Pretty much every aspect of SI I am struggling with. These are some I took 2 weeks ago.
http://i49.photobucket.com/albums/f2...pscbc680f5.png
http://i49.photobucket.com/albums/f2...ps79086d57.png
http://i49.photobucket.com/albums/f2...pscbc680f5.png
Go SI full screen, it's working,
Make sure and raise the motor abit if it's in the way of the transducer.
Mark something," go to it".
Check it out on DI, you got it.
Ps , go left and right view full screen
Let's use this one as an example (but just speaking of the SI image side)...
http://i49.photobucket.com/albums/f2...ps79086d57.png
There are 2 side pointing SI beams (one pointing left 30° from horizontal...one pointing right 30° from horizontal)...
These sonar beams are very narrow front to back...but very wide top to bottom...(picture a Chinese folding fan opened upside down under your xducer...)
Each time the unit pings, the unit takes the echo information in that thin slice and plots that echo information on the SI image across the very top of the SI image in a thin line...1 pixel thick horizontally across the display...
The very next ping echo information is plotted at the top of that same SI image... Pushing the previous echo Information down on the image...into the "History"...or "what you have already passed over"...
It is this pinging, plotting, stacking (of the thin lines of echo information on the image) .... That builds the SI image on the screen...( it is not a camera snapshot of the bottom)...
It is very similar to how an MRI works...pictures of individual slices...and then those slices are stacked together by the processor to make a "compiled" image of the whole....
The vertical centerline is your boat's track...
Everything to the left of the centerline is being "pinged" by the "left pointing" SI sonar beam...
Everything to the right of the centerline is being "pinged" by the "right pointing" SI sonar beam..
The wide dark strip on each side of the centerline is the water column between your xducer and where that side's SI beam 1st contacts the bottom...
The wide lighter strips to the outside of the dark water column is the bottom detail from where that side's SI beam 1st contacts the bottom and continuing out thru the possible "reach" of that SI beams ping strength...(the ping is a sound pulse and it only carried out so far before it fades to nothing)...
Now...help me help you...which part of my gobbledygook can I break down into something that can help you...??
Rickie
I was running along the dam of a small community lake and didn't see the need for it to be going 360 so I just ran it so it was looking out away from the dam.Quote:
Originally Posted by brettw
I'll get some screen shots of SI this afternoon. Interpreting what I am seeing is the thing I have the most issue with. Currently if I see something that I think is fish I chuck a marker buoy out in the approximate area then switch to DI and go try to find them.
Does the side image beam go out at 90deg. angle or at a lesser degree?
Your DI pics of those fish are great :ThumbsUp I'm still trying to understand what I'm seeing on the SS also.
Doug does a good job explaining side scan in this video. Doesn't matter what brand, the concept is the same.Quote:
Originally Posted by zummy
https://www.youtube.com/watch?v=3xe6pLPdMKc
The center "Main Axis" of each SI sound pulse is emitting at 30° from horizontal....the sound pulse is strongest at this "Main Axis" ...and then the sound radiates out and away from the xducer in an "ever-decreasing" sound strength....Quote:
Originally Posted by minnowtime
Below is the beam form of the right SI sound pulse....mirror this with the left SI sound pulse...(and remember...the SI sound pulse is a thin slice...so the beam form shape below is only a couple inches thick front to back....with each single ping)....
http://i477.photobucket.com/albums/r...pshmz3szda.jpg
Rickie
See if this helps zummy...
I took this screenshot of yours...
http://i477.photobucket.com/albums/r...pshkmvomhq.png
-----------------------
I edited the screenshot...
*The green circles are fish (white echoes)....
*The blue circles are depressions in the lake bottom...
http://i477.photobucket.com/albums/r...ps0xa9vmy6.png
Rickie
Here are some from today
I see a fish just to the left of the boat in this one
http://i49.photobucket.com/albums/f2...ps719b1cd7.png
I don't see much of anything here
http://i49.photobucket.com/albums/f2...psb0c3cc7c.png
These two are obvious
http://i49.photobucket.com/albums/f2...ps85103de1.png
http://i49.photobucket.com/albums/f2...psd23838f4.png
Here's your 2nd shot again...
http://i477.photobucket.com/albums/r...psmczmgyu2.png
Rickie
IMO turn your contrast down some.
Rickie,on 800 khz,what do first null mean?
Keep looking, decrease range a bit, (to 60) , you'll find cool stuff soon.
And go full screen
Rickard at sideimagingsoft explains it much better than I can...Quote:
Originally Posted by genec
The null is a mathematical thing and in theory no sound at all is transmitted or received in that particular direction. However, in a practical transducer this silent point doesn't really exist. It is filled to some extent with sound, but weaker than in other directions. The effect of the null is a dark or dull band, usually near the middle of the sonar image.
--------------------
I think most would see this darker band in the image and think that it's simply a different bottom composition....
I wish I knew an small iota of the "wave theory" that Rickard knows...and he's a great guy too...always willing to help...
Rickie
Rnvinc,
You took this screen shot and determined his SI was showing depressions on the lake floor. How did you come to that conclusion and not think they were rocks or humps. The only reason I am asking is because I don't know
a hole leaves a dark spot whereas a stump would show shadow behind the stump,rickie will explain it better
Like Gene mentioned ...a hole or depression leaves a dark spot on the edge closest to the beam...Quote:
Originally Posted by brush pile
Because the SI beam is travelling at an angle away from the xducer...the inside edge of any depression would not have any sound pulse data for it...because the lip of the depression closest to the beam travel is blocking the sound from getting down into the hole enough to show data for this area of the hole...
Imaging shining a flashlight at an angle across any dark hole...the leading inside edge of the hole would still be dark...
In sonar (2d/DI and SI)...a shadow is nothing more than a "void" ...of which there is no data....(our mind simply interprets this "void of data" as a shadow in the image)...
Rickie
rnvinc Thanks for all your helpful info.
If I understand it right with side imaging the 30 deg. angle, the signal would run aground in about 21 feet if you were setting in 10 feet of water. If this is true it would be hard to see suspended fish unless they were real close to boat.
We have to remember that the 30° number is the "Main Axis" of the thin slice beam...or the strongest part of the sound pulse...(just like standing in front of a speaker...the sound is louder directly in front of the speaker and weaker at any angle away from the speaker)...Quote:
Originally Posted by minnowtime
The sound not only radiates along the "Main Axis"...it also radiates laterally away from the "Main Axis" at the same time...
While your calculation is probably correct that the "Main Axis" will run aground at 21ft away from the xducer in 10ft of water...:
There are still weaker parts of the sound wave are that hitting the ground closer than 21ft (under the 30° "Main Axis" angle...and farther than 21ft (above the 30° "Main Axis" angle)...
The processor and the algorithms designed in the unit determine which echoes in the weaker parts of the sound wave are worthy of being "painted" into the image....and whether those weaker echoes should be painted as fish, structure, or bottom detail...
Rickie