Printable View
I typically vertical fish over structure. Often times I am not moving at all unless the wind is blowing and even then I try to stay stationary over the structure. My DI mode does not look much different than regular sonar. It is not creating an actual image of what I am over. Is it because I am stationary or does someone out there have the magical set of settings for producing and image when fishing this way.
Thanks
Technically, yes .... you're not going to get that "picture" with a DI unit, unless you are moving. DI units have a different shaped cone than "regular sonar" (ie - 2d). 2d cones are an ever expanding circle, whereas a DI cone is an elongated fan shaped slice of water. When you are stationary, your pings are hitting the same obstacles from the same direction ... so the return signal is going to be the same (constant), and your "image" is going to be drawn out across the screen. When you're moving, the signals are hitting the obstacles from different angles as you move, so the image is drawn from that info. This is more understandable, if you realize that the image you see on the screen is not a "camera" picture of what's underneath the transducer, but a composite picture of the return signals per their distance from the transducer. Only the portion of the image that shows on the far right of the screen is "new" & relevant information (at that instance), and the rest of the screen is showing "history" (the unit's program's composition of info turned into an image).Quote:
Originally Posted by PoleNHand
Best use of DI is to locate the cover you intend to fish .... then use the 2d sonar to stay in contact with it (or use marker bouys).
That's just my take on it .... others may have a different take. Check out the Electronics/Trolling Motor Forum for more precise answers, from those with more electronic & technological knowledge.
... cp :cool:
Yep, if your sitting still your seeing less than you would on an 80$ black and white unit
2d cone shaped sonar beam vs DI fan shaped sonar beam...
Each time the unit pings.. It processes the echo data in the sonar beam shape and plots that info onto the unit screen to the far right of the screen (a few pixels wide) pushing the "previous" pings data info to the left on the screen (history)...
If the fan shaped DI sonar beam is not moving... The unit is "pinging" the exact same small "slice" of water plotting "copies" of the same echo data onto the screen again and again...
The fan shaped DI sonar beam has to ping a "new" slice of water each time so that when the processor "stacks" these slices together on the screen... The slices will build an image that we see as a DI image...
http://www.crappie.com/crappie/attac...enshots-1-.jpg
http://www.crappie.com/crappie/attac...0-45c336a5.jpg
Rickie
Pappy.. I went back and read your post and my post and I think you explained it better than I did...:)
You are more of a sonar "guru" than you give yourself credit for...
Rickie
Rofl ... I don't know about that, Rickie ... but, I'm learning from ya'll & trying to wrap my head around this technology.Quote:
Originally Posted by rnvinc
... cp :cool: