Microphones position for sound source localization

Hello,

I've recently studied some papers about sound source localization method.
As I know, 3D sound source localization can be done by Time Difference of
Arrivals (TDOA) & Generalized Cross Correlation (GCC) methods with four
microphones placed on different plane.

Its a question about microphone position, how can I place them well for
optimization ?!

If the environment is a public square outside, can I put them at corners,
spaced more than 10m apart from each other ?!
This question arised coz all papers which I surveyed keep them apart just
no more than 50cm. 
I dont know whats the effect of putting them at so different distance. 

Thanks

Ryan

lapidarylee wrote:
> Hello,
> 
> I've recently studied some papers about sound source localization method.
> As I know, 3D sound source localization can be done by Time Difference of
> Arrivals (TDOA) & Generalized Cross Correlation (GCC) methods with four
> microphones placed on different plane.
> 
> Its a question about microphone position, how can I place them well for
> optimization ?!
> 
> If the environment is a public square outside, can I put them at corners,
> spaced more than 10m apart from each other ?!
> This question arised coz all papers which I surveyed keep them apart just
> no more than 50cm. 
> I dont know whats the effect of putting them at so different distance. 

General antenna theory applies. Beam width ~ wavelength/spacing. However 
if the spacing is more then half of the wavelength, then the directional 
pattern will have multiple beams. You will have to resolve the ambiguity.


Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

On May 8, 3:17 am, "lapidarylee" <Ryan_...@ali.com.tw> wrote:
> Hello,
>
> I've recently studied some papers about sound source localization method.
> As I know, 3D sound source localization can be done by Time Difference of
> Arrivals (TDOA) & Generalized Cross Correlation (GCC) methods with four
> microphones placed on different plane.
>
> Its a question about microphone position, how can I place them well for
> optimization ?!
>
> If the environment is a public square outside, can I put them at corners,
> spaced more than 10m apart from each other ?!
> This question arised coz all papers which I surveyed keep them apart just
> no more than 50cm.
> I dont know whats the effect of putting them at so different distance.
>
> Thanks
>
> Ryan

When doing TDOA with GCC via DFT by the most straightforward approach,
remember that the DFT time window must span an interval big enough to
hold the duration of the signal you with to locate plus the longest
element to element transit time at speed of sound.

Dale B. Dalrymple

On May 8, 3:17&#4294967295;am, "lapidarylee" <Ryan_...@ali.com.tw> wrote:
> Hello,
>
> I've recently studied some papers about sound source localization method.
> As I know, 3D sound source localization can be done by Time Difference of
> Arrivals (TDOA) & Generalized Cross Correlation (GCC) methods with four
> microphones placed on different plane.
>
> Its a question about microphone position, how can I place them well for
> optimization ?!
>
> If the environment is a public square outside, can I put them at corners,
> spaced more than 10m apart from each other ?!
> This question arised coz all papers which I surveyed keep them apart just
> no more than 50cm.
> I dont know whats the effect of putting them at so different distance.
>
> Thanks
>
> Ryan

Tricky - the more mics the better. Depends on the locus of the unknown
source wrt the array.


Hardy