this is my first post here and I am also new in signal processing.
Let's say I have a hydrophone with amplifier which is connected to a sound card plugged in to a computer. I gather the sounds to a WAV file every 3 seconds and analyze each file in a Python program. The system is supposed to detect loud events which are dangerous for sea animals.
I would like to know how to reliably measure acoustic pressure (loudness?) of events occuring under water based on WAV data. I am not sure if I should use exactly the same formulas as measuring SPL in air. I do not have the hydrophone yet so I can not really tell anything about it at this moment, but I am pretty sure the catalog notes of the hydrophone will be available for me when I finally get it.
It would be good enough if the measurement had an error under 5 dB SPL. It does not have to be perfect, I just want it to be relative and adapted to under water characteristics.
Could the simple measurement be calibrated by shifting measures by single constant in dB?
I found a similar solution in Determine Sound Intensity in SPL. But the problem is I do not know if I will be able to have all the data needed for this, mainly about amplification levels. Would the calibration-like solution be good in this case? How can I do it?