How can I find the attenuation of the pressure signal
 

Hi all,,

I have of pressure signal data obtained by sudden closing of valve along the pipe line i,e it is pressure surge or water hammer.

According to the theory , pressure signal obtained is attenuated. My question is how to find out the attenuation of the pressure signal obtained for me. I simulated water hammer problem by solving differential equations. I got pressure signal simulated.
I want to apply attenuation for this signal also.. How I can apply attenuation to this signals?

Please advise me some articles or some hints to find out the attenuation of both the signals (experimental and simulated)..

Thank you in advance