Topic: how to determin the size of a wreck

[sjefsrafsern]

hi guys, we just stumbled across a wreck while fishing. and have tried diffrent methods to determin the size of the ship, but get diffrent results from eatch image. so if anybody can help it would be nice. 

[sjefsrafsern]

2

[sjefsrafsern]

3

[sjefsrafsern]

1

[sonar2000]

If you install humviewer (available here from this forum) you can view a recorded sonar scan and then when reviewing an object you can use the measuring tool in humviewer.

Also look at #3 and you can see that the boat starts at just about 75 feet on the range lines and goes to about 110. So approximately the boat is 35 feet long..

Chuck

[Rickard]

But Chuck,
I think it's about 90 feet long... The stern seems to be located directly below the transducer so the horizontal distance to the stern from the boat track is zero. Slant range from the transducer to the bow is about 110 feet. Then slant range correction shows the horizontal distance to the bow must be 80 feet. The wreck is oriented at about 30 degrees from a direction perpendicular to the heading of the transducer so the wreck must be a bit longer than 90 feet.

Rickard
 

[sonar2000]

Rickard, you are right, I was thinking slant range from a different view.
Yes it does look like the boat is directly beneath the surface craft and goes out to almost 110 feet.
thanks for looking closely at the picture and pointing this out..
It seems the DI picture also points this out..

Hmmm. now where did I put those reading glasses.. 

Chuck

[sjefsrafsern]

thank you guys.  im going to download the humviewer, so i can do this my self next time something interesting comes up. and thanks for the calculation. 

stig

[sonar2000]

Stig, I think you will find humviewer a very useful program.
for a hint with recordings, it is best to keep then time to not more than 30 minutes.    This way the file will not be too big and easier to manage and view.

You might want to read the followingn also..

http://forums.sideimagingsoft.com/index.php?topic=937.0

http://forums.sideimagingsoft.com/index.php?topic=628.msg11764#msg11764

chuck