The speed of sound doesn't vary with freq but it is dependent
on temperature and the density of the material medium. Perhaps you
are thinking of the tendency of higher frequencies to dissipate
faster than lower over a given distance...
thanks for the BatSystem pointer -- looks like it could be useful.
MS
Urs Hunkeler wrote:
Hi,
If you control the noise source, then I would do as Michael suggests.
The project I remember is called ActiveBAT:
http://www.cl.cam.ac.uk/research/dtg/research/wiki/BatSystem
If you can't control the source and in particular don't know when the
sound source started emitting, you can't use timing with a single node.
You still could triangulate the sound source's position if you have
several nodes whose position you know and with which you manage to
establish the phase difference of the received signal.
If you have a fairly good idea of the characteristics of the sound
source, especially the amplitude of the signal it emits, you could
probably estimate its distance by measuring the amplitude of the
received signal. This would be extremely imprecise.
I seem to vaguely remember that the propagation speed of sound depends
on its frequency (maybe only true for underwater?). In that case if you
know the characteristics of the original sound you could probably
calculate the sound source's distance by measuring the distortion of the
signal.
Cheers,
Urs
Michael Schippling schrieb:
_never_ use IE....heh...
My memory fails on the details, but there are some examples of timing
the difference in reception time of an audio ping with a simultaneous
radio message. Perhaps three or four years ago...
I can't even come up with a good set of keywords right now, but some
grueling google or list searching should get you pointers.
MS
Mohammad Allouh wrote:
hi
sorry for the previous email, it is becuase of IE, any way ....
I am using tinyos 1.1.13 , MIB510, MTS300 from crossbow
I have implemented an application to read the MIC reading from the
sensor node and dispay this value while it is changing
my question is: Can I use the MIC readingto estimate a relative
distance between the wireless sensor and the sound source ?? if so ,
HOW ????????????
thanx in advance
------------------------------------------
Mohammad Sa'ad Allouh
Mobile: 0788131024
Email: [EMAIL PROTECTED]
Irbid - Jordan
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