distance from probe?

Would you please to tell me that how the SSC influences the detection of the bottom of Sontek Vector?  
In my field data, I found that sometimes the Vector can detect the bottom. However,sometimes it would report a zero distance from the probe to the bottom. I want to know the reason of it. Is it affected by SSC? When the SSC is too high, the vector can not detect the bottom, so it will report a zero distance from the probe to the bottom? Can you tell me with what SSC it could work properly

Thank you!

Well, let's hope it is a Nortek Vector...... 

 

 

The SSC will influence the ability of the acoustic signal to distinguish between the bottom and the water.  To simplify things a little, you can think of it as a problem where the reflection from the bottom is constant for a given site whereas the acoustic water return is proportional to the SSC. In order to identify the position the bottom, the bottom scattering must be stronger than the water return.  As the SSC increases this becomes more difficult and at some level the Vector can no longer identify the bottom position.

 

In the latest version of the Vector firmware, we record the acoustic scattering profile at the beginning of every burst.  This allows you to see the data for yourself.  If you work off a complete data set (and not just individual profiles as we do), it is fully possible that you can come up with an algorithm that finds the bottom at times where our software does not   

 

 

Best regards,

 

Atle Lohrmann

Thank you very much.

Would you like to tell me what's the latest version of the Vector firmware which record the acoustic scattering profile at the beginning of every burst? And for the old version, can it be updated with the new version of the Vector firmware.

Thanks again.

Hi there

 

The first version of the Vector firmware that will measure the distance to the bottom at the beginning each burst is version 1.20.  There were a few beta version sent out early in the year but this is the first publically released version.

 

Any Vector can be updated to use version 1.20 . 

   Just go to the support area on our WEB site and download the firmware and the corresponding software.

 

Best regards, Atle Lohrmann

Hi Atle,

Thanks!

Best regards,

dekeete

How can I see the distance to the bottom with version 1.20 if I'm logging continuously?  In the hdr file, I do not see a reference to distance to bottom in either the sen or dat files.

Thanks,

-Jon

 

Dear Jon, I don't think you can.  The distance (i.e. echosounder data) is only collected at the beginning of each burst.

Best regards, Atle Lohrmann