Topic: DI if mounted on its side

[ctf58]

I was reading in another post and came across this post from Rgecy

"Basically Down Imaging is nothing but Side Imaging in a verticle or traditional 2D view.  The two SI images are combined and filtered to give you the view under the boat.  Some people have a harder time understanding SI and for them the DI is more of what they are use to with traditional sonar.  I think there are some very good advantages to DI, especially for fishermen, but as I have stated before, you really are not gaining any new data from the DI view. "

So it made me think, could I in theory mount my DI transducer say 45 degrees to the left and have Side scan imaging  to the left? Just wondering if anyone else every thought of it or tried it. I know it sounds odd?

[rnvinc]

In effect you can point a xducer in any direction and get echo returns....(as long as it is in water)....

You would just need to know how to interpret the images...

You would not get the same SI "look from above" layout image from a dedicated DI xducer..
The SI image is as if you were hovering above the water looking straight down into the water...
The DI image is as if you were down in the water looking sideways across the lake bottom...

Below is a depiction of the dedicated DI sonar beam...so picture this fan shaped beam pointed in any direction you choose... While you could gain echo returns more out to the sides by tilting the xducer... The image on the screen will still look like regular DI (with an incorrect bottom reading)...

[Rickard]

This has been tested by our russian friend Alex (and perhaps by some other people too):
http://forums.sideimagingsoft.com/index.php?topic=2563.0
I don't know how far he pushed his project, if he ever tried with a y-cable.
 
Rickard

[ctf58]

thanks guys! I posted a question to Alex_under on his topic.

I was also wondering if manually setting the depth would limit the distance, sort of like on a SI unit setting to read 100 ft to the side.

The whole reason for this post is two fold.

1. I like to tinker with stuff.
2. DI is great if the water is deep enough. I typically fish in less than 20ft of water so I'm not seeing a large area. If I were jigging under the boat that would be fine, but I bass fish and thought if I could "see" to the side out, say 75ft then I could cast to something without having to first drive directly over it to find it and possibly disturb the fish. I understand the depth reading would be off but I think a person could learn to adjust for that. I also thought about manually setting the depth to see if the unit reacted somewhat like setting a SI unit to scan 100ft out to the side.

I have my ducer mounter to the trolling motor so I was in theory thinking as Alex_under. angle it about 30 degrees off vertical plus with it being on the trolling motor I could literally look around 360 degrees by slowly turning the motor..

I'm not having buyer remorse, I just did not think about the area  I could see in DI under the boat and I bought the unit for "Finding" structure. I can not afford a SI unit and thought this might be a "poorboy's" solution.

Thanks again
Clint

[Roddy]

CTF58, check out interphase.com. They have all kinds of forward scanning units. It will save you a headache too.

I use a twin scope, works for me.

[ctf58]

CTF58, check out interphase.com. They have all kinds of forward scanning units. It will save you a headache too.

I use a twin scope, works for me.

Thanks but the even refurbished stuff is a little out of my price range

$1,699.00
Refurbished Color Twinscope with two Transom transducers.

If I could afford that I'd get a Humminbird® 898c and still have $200 in my pocket.

[rnvinc]

I saw a video by a gentleman on another forum that took a regular 2d xducer and mounted it in on a pivot with a servo motor...

When the servo motor activated...the xducer pivoted 90 degrees where he could scan under boat docks for suspended fish...

The unit did, in fact, mark fish with depths (more like distances to) each fish echo return...

Sonar only measures time and then calculates that time into distance....

Sonar doesnt care which way it measures this time (distance)... The user decides which way to "aim" it...

Rickie

[ctf58]

Thanks Rickie, that is what I was trying to get at but for structure as much as fish in the DI mode. If I mount it angled on the trolling motor I could "look" around the boat instead of under it. I might just have to give it a try!

[sonar2000]

We have done that with the 200 kHz transducers just to look under docks and back in crevices. With the side image we dont seem to use that much any more but it will work. You just have to get you head straight that you are looking sideways and not down.
Remember the beam cone size also..

chuck

[Humminbird_Greg]

Clint,
Try using the Max Depth and Lower Range menus to limit the distance that the unit will look and display to in the DI sonar.  This should do what you are looking for.

[sonar2000]

That will limit the screen display but remember the recording will go all the way.... so if viewing on an external it will show the max depth..
Chuck