k-Wave

1. weigler
   

   Member
   Joined: Nov '16
   Posts: 3

   Hi all,

   I'm simulating simple wave propagation in lossy media. A single source is emitting a sinusoidal signal which is meassured with to sensors in some distance from the source. Said sensors are 1m apart from each other.
   The maximum frequency is at 3kHz.

   Choosing medium.alpha_coeff = 0.1 and alpha_power = 0 should lead to 10dB attenuation between both sensors. This seems to be true for frequencys between 300Hz and 3kHz. Below 300Hz the attenuation drops rapidly.

   Can anyone explain this behaviour? Is it possible to turn off frequency dependence by choosing y=0 at all, as the formula suggests?

   Thanks a lot and merry Christmas to all of you
   Tobias

   Posted 8 years ago #

2. Bradley Treeby
   

   Developer
   Joined: Mar '10
   Posts: 1,643

   Hi Tobias,

   Practically, I haven't worked much with power law values outside the range seen in biological tissue, where 1 <= y <= 2. I agree that in principle, it should work.

   Using the Modelling Power Law Absorption Example with the alpha_power values set to 0 seems to give approximately the correct behaviour (remember to change the example_number at the beginning of the script). What happens if you adjust this example to use the frequency range and sampling parameters you're interested in?

   It could also be a issue related to how you're sampling or processing the data.

   Brad.

   Posted 7 years ago #

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