Thread: Here you go!

Why the black line down the middle of the ship image?

Canada identifies ship from British Arctic expedition | Fox News

That's a cool story ...



The "black line down the middle of the ship" is the "Range distance" from the xducer down to the deck of the ship...
(Their SI Image does not have the boat track "graphic" vertically drawn in the center in the SI image as most SI units do)....

Because there were no echoes in the water column between the xducer and the deck of the ship...the unit "paints" this as "no data" = black...(it just looks unfamiliar without the boat track graphic that we are accustomed to seeing in SI images)...

It's the same as this bridge being cross scanned....(if we removed the boat track graphic line ... The bridge would look like it had the same black gap vertically down the middle as the ship from above)...



Rickie

Good info here!

I should used that one as a sonar quiz...



Rickie

Pretty cool find. Look at the gaping hole in the ( I'm guessing) bow.

cant you take out the water column and make it show just the bottom image and there would not be a void in the center of the picture?

Originally Posted by Knappy

cant you take out the water column and make it show just the bottom image and there would not be a void in the center of the picture?

The HB SI units can remove the water column in the SI image ...

It's called "Contour Mode"...under the SI Enhance sub menu...

Rickie

Very interesting article and thanks for posting the link.