DI snapshot of bridge piling

I posted this a while back but we have new members now....

This is a bridge piling that I captured using the 800kHz beam of my 1197...

Remember now that the DI (in a HB SI unit like my 1197) is rendered from the SI crystals in the xducer...
Also remember that the 800kHz only covers 135 degrees (not all the way to the surface like the 455kHz 180 degree SI beam)...therefore the upper portion of the bridge piling was not physically in the SI beam ...so the snapshot shows the upper part of the piling as absent...

http://i477.photobucket.com/albums/r...c/892ccd9c.jpg

Rickie

ok, I see the 4 pilings.

Are the pilings laying on their sides or upright?

Is this bridge standing or on its side?

What is the solid yellow line that runs all the way across just above the pilings ?

What is the yellow "canvas" or cover above the solid yellow line I referred to above ?? part of the roadway??

New at this DI/SI, have seen lots of the pictures but never studied them much but since I have a HDS 8 now, gotta learn what I'm looking at now.

See if this helps understand the perspective of the actual bridge piling as it compares to the DI image..

(Remember this is a DI image..even tho my 1197 uses the SI crystals to get the sonar information to render into the DI image...the 1197 processor displays the DI image is as if you were standing on the lake bottom looking sideways at the piling...)

(Also remember I used the 130° 800kHz SI/DI sonar beam to scan this bridge piling...so the portion of the piling above the upper scan line of the 130° beam does not collect data so it cannot display data that is not in the 130° beam...)

http://i477.photobucket.com/albums/r...c/892ccd9c.jpg

http://i477.photobucket.com/albums/r...inc/piling.jpg

Rickie

I like the diagram. It helps to understand the image. Thanks!

rickie, that helps