Hi @Lulu,
Apologies for the late response - I just stumbled across this and saw I had missed an update from you.
If this is still relevant, sure, or something like it (e.g. with typed text so it looks a little more formal) 
The processing is proprietary, so I’m not sure, but I don’t believe the “strength of response” values can be directly correlated with pressure dB -
If it’s relevant, there’s now an open source sonar firmware that you could use to run your own processing/filtering (or lack thereof) to try to get closer to the data you want, although if you remove the temporal sub-sampling and return strength processing you may not be able to use the existing protocol messages, at least not as intended.
Interesting application! 
I see - that’s likely better implemented inside the sonar if possible, rather than trying to send the full soundwave samples out and process them in post.
Again, apologies for overshooting this - I hope you were somehow able to perform the analysis you were intending to 
Presumably that would be easier to do now with the open firmware option, if the project (or its offshoots) happen to still be ongoing…
We’re always interested in understanding how our components are being used in research and interesting applications. If you’ve got an available paper or thesis we’d be happy to add it to the Subsea Scholar (research paper directory) section of our website