Patch Test for Sidescan?

[Jon]

Hi there,

for some time now, I have been searching for acceptable methods of patch testing a side scan? Are there any industry standards on field calibrating a side scan short of imaging a known target in different swaths and a different speeds?

Thank you

Jon

[John K]

Jon,
This may be redundant to your knowledge, but I used to tune my Wesmar 700 by hanging it off a dock, similar to the patch testing you are seeking. Find a steady target like a boat or piling, set the range from 300 to 600 ft (depending on distance). Then I would go through each receiver and individually tweak each pot until that target was as strong as possible. The guys at Wesmar have a test tank so they can get a better tune, but they recommended this to me years ago and I've done it about once a year since.

This is what I call 'field calibration' and I believe it has worked without any problems. Just make sure you and the target are both steady. Also, my towfish had adjustable transducers so it was easy to turn them forward without having to move the towfish before testing each side.

I do not know about testing the speeds but since I have never once been able to get the same picture twice, this is the prefered method for me. Don't attempt to tune your sidescan unless you have a clue about what you are doing. Good luck
JK