In this 2d and downvu pic of the same spot, what is 2d doing in this situation with the ghost-like representation of the rock?
Is it just a matter of the rock being on the outside edge of the cone?
In this 2d and downvu pic of the same spot, what is 2d doing in this situation with the ghost-like representation of the rock?
Is it just a matter of the rock being on the outside edge of the cone?
Last edited by Chief Brody; 06-16-2019 at 08:09 AM.
I agree it looks a little strange. Really sharp looking down image.
Wayne Purdum
Charlottesville, Va.
Helix 12 CHIRP MEGA+ SI G3N/G4N, Helix 15 CHIRP MEGA SI+ GPS G4N
SOLIX 12 SI/G3, Helix 8 CHIRP MEGA SI+ G4N, Ultrex 80/LINK, MEGA360,
MEGA LIVE, LIVE TL
Wayne, your downvision shot is even crazier looking than mine
this is awesome down image!
Tangrine Orange Key 16604126S1
Looks like a termite eaten tree trunk!!
John
I dropped the ball on this one: my shot is from Homeport, but I didnt use it much because its about useless for sidescan. But i couldve got some good 2d and downvu recordings with shots like mine
??? Is Homeport useless for side scan on is the unit?
ya still pretty much useless for sidescan. I didnt realize it was still useable for 2d and downvu, though.
Tangrine Orange Key 16604126S1
Tangrine Orange Key 16604126S1
Whats going on is a result of how downsvu works vrs 2D.
You have to remember that a downvu image is basically what you get if you draw both sides of a sidevu image on top of each other at the same time. Downvu "sees" off to both sides of the boat using a very narrow (front to back) cone - just like sidevu. The difference is that sidevu draws the right and left images on opposite sides of the screen - and it scrolls down from the top.
Downvu "sees" the exact same returns - but - it draws them both at the same time right on top of each other. That can often make for muddy, confused, and distorted images. When the structure is mostly or only on one side, then you get the pretty pics.
Heres an example of a 2D, sidevu and downvu images of the same piece of bottom that shows whats happening with some logs that were almost dead center when I passed over. You can see what was an almost straight log that looks bent and under the ground, but its really just the two sides of the same log on sidevu drawn on top of each other.
The 2D looks totally different because it is also drawing things from both sides, PLUS, its drawing things that are ahead of and well behind the transducer - all at the same time. In my case, there isnt as much difference as your pics mostly because the bottom where I was was really flat.
Last edited by Larry3215; 06-21-2019 at 12:08 AM.
Smokercraft Phantom 202 Yamaha F115/Merc 9.9
Garmin 7610xsv/GT51M-TM/Panoptix PS21/LiveScope
Why am I hanging out here when I could be fishing.....
Sorry, grabbed the wrong 2D image. Fixed now.
Smokercraft Phantom 202 Yamaha F115/Merc 9.9
Garmin 7610xsv/GT51M-TM/Panoptix PS21/LiveScope
Why am I hanging out here when I could be fishing.....
Thanks Larry
Ya it was the 2d image that had me wondering. i always thought the 2d cone would see the edge of an object that was higher up and draw it as the bottom. But in my case it drew it along with the actual bottom.
Wayne Purdum
Charlottesville, Va.
Helix 12 CHIRP MEGA+ SI G3N/G4N, Helix 15 CHIRP MEGA SI+ GPS G4N
SOLIX 12 SI/G3, Helix 8 CHIRP MEGA SI+ G4N, Ultrex 80/LINK, MEGA360,
MEGA LIVE, LIVE TL
Tangrine Orange Key 16604126S1
Tangrine Orange Key 16604126S1