Assuming constant speed of sound, this problem amounts to finding the
intersection of 6 (=3D 4 choose 3) hyperboloids. The differences in the
times of arrival of the sound at the different hydrophones gives the
difference in the distances of the sound source from the hydrophones;
the collection of points equi-distant from two given points is a
hyperboloid.
Since measurements won't be exact, you'll probably need some sort of
least-squares procedure to find an approximate solution.
If that's enough of a hint, great! Or, feel free to email me directly if
I can help with explicit formulae, computer code, etc.
Steve P
Gianni Pavan wrote:
>Hi all,
> I have some multichannel recordings made with 4 hydrophones, 3 of wh=
ich
>are mounted on a same plane and the fourth higher then the other 3.
>I'm in search of an algorithm to calculate the direction (bearing and
>elevation) of an acoustic source given the time delays I measure on among
>the four hydrophones and their 3D coordinates.
>Any hint will be much appreciated!
>
>Gianni
>--------------------------------------------------------------
>Gianni Pavan
>Email
>Centro Interdisciplinare di Bioacustica e Ricerche Ambientali
>Universita' degli Studi di Pavia
>Via Taramelli 24, 27100 PAVIA, ITALIA
>Tel +39-0382-987874
>Fax +39-02-700-32921
>Web http://www.unipv.it/cibra
>
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>
>
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