How to read a fish finder display

[jtexas]

Maybe I'm just too dense to understand....<br /><br />The signal return from the transducer to the F/F represents a more-or-less horizontal circular plane under the T/D, right? A cross-section of the cone-shaped area where the bottom (or whatever) intersects the T/D signal?<br /><br />The display is a representation of a vertical plane, surface to bottom. <br /><br />So, the question is:<br />How does the F/F translate the horizontal plane to a vertical plane on the display? How does it "decide" which vertical cross-section of the T/D return to show? I mean, when I see structure or fish or bottom contours scrolling past on the display, how do I determine where they are in relation to the boat?<br /><br />I just couldn't find a website that explained it in language I could understand.<br /><br />Any insight would be appreciated.<br /><br />thanks,<br />jtw

 

[18rabbit]

Re: How to read a fish finder display

It is simple sonar. Try here for an answer to your question:<br /><br /> http://www.sidefinding.com/site/html/htmlsite/how_fishfinders.htm

 

[Boatist]

Re: How to read a fish finder display

J Texas<br />Pretty easy really. You can not tell where the fish are in relation to the boat.<br />All you can tell is what is in the cone of the transducer, what is directly under the transducer. That is displayed as the far right row of dots from top to bottom. That image then moves one pixes to the left and what is in cone angle of the boat now is displayed on the far right. The far right row of pixels from top to bottom is what is under transducer now. Every thing to the left of the right most row is history. The way you find out where the fish are is by moving the boat until you see marks above the bottom. Check this tutor and watch how the fish arch is made it might help. If you are trolling and the fish are staying in the same place then the arches you see in the middle of the screen are behind the boat. Those to the far left are way behind the boat. The one on the far right are under the transducer.<br />Hope that helps some.<br /><br /> http://www.lowrance.com/Tutorials/Sonar/sonar_tutorial_01.asp

 

[jtexas]

Re: How to read a fish finder display

Okay, I think I got it now - everything in the transducer cone area gets mashed into the first pixel column and everything else is history. I'm really not as stupid as I look .<br /><br />thanks guys, that was helpful,<br />jtw