cross correlation

[Do_Tech]

Hi, add an attachment with the code and an example of wav. The purpose of this code is to obtain the delay between the signal acquired by MIC1 and the same signal acquired by the MIC2. The whom are separated at a distance known, so the signal to reach one before the other. As I unlock both the cross-correlation and coherence the cross-correlation does not give the true delay between a signal to another. The final application is to build an array of microphones for the detection of the angle of arrival.

The analysis is done by pieces of the signal sample.
(Control) "Time Signal" = specify the time signal where we want to perform the cross-correlation. Ex. : Time signal = 1.5 (seconds)
(Control) "Length" points = length of the correlation. Ex. : Length = 100 (points)

Greetings...

[DavidOna]

Hi Do_Tech,

I don't really understand why you use correlation when developing your application. Could you please give me your reasons? It seems to me the typical problem in calculating the delay a certain wavefront takes to arrive from one position to another. If the distance between both microphones is small enough you can consider the wavefront to be a flat and you only need to compare the acquired signals with a bit of signal processing. However, you must be sure you've done a synchronized acquisition.

Concerning your code, I don't understand some details: I get the idea but I don't know exactly how it works. Anyway, I recommend you to check Context/Labview Help when using a VI, because there are lots of disconnected inputs in your VIs that are probably taken the default values and, as a result, the VIs aren't working as you expect to do it.

Regards,