Comparing the amplitude of two signals

[akash90]

Hey guys,

I'm looking for some help with comparing two similar signals (acquired using two different sensors). I would like to compare (point-by-point) amplitudes of the two acquired signals and get a normalized result, a number between 0 and 1 (1 implying a perfect match and 0 a non-match).

I did find something similar on the internet that I have attached here as an example. Any help/leads are appreciated 🙂

[GerdW]

Hi akash,

sounds like you want to cross correlate two signals...

[Kyle97330]

Right now this doesn't sound like a "LabVIEW problem", it sounds like an "Algorithm problem".  While sometimes those of us here are generally helpful fellows who enjoy giving advice, this may be stretching it too far, as you could have posted this problem on a message board for any given computer language. 

If you have problems collecting the data, or problems syncing the sensor signals, or you have an algorithm but can't figure out how to write it in LabVIEW, that's a lot more along the lines of what we generally assist with.

For now though, I will point out that there are 3 different correlation VIs on the "Probability & Statistics" palette, you could see if they do what you want already...

[Henrik_Volkers]

Looking at your past posts, it seems that you want to do some investigations on MEMS accelerometer using LabVIEW .....

If you cite someone, you should note the source! 

So, after looking at the source , my question is: What is your question you want to answer?

(or what is YOUR task?)

(I'm missing the cohenrence measurement between two equal sensors at the setup shown in this paper, (maybe also with swappped sensor positions)  and some words about uncertainties ... 🙂 )

[akash90]

Hello Henrik 🙂

Yes, indeed I'm doing some investigations on a MEMS accelerometer using LabView (and that is the reason why I posted this question here @Kyle97330 :).)

I agree that I should have cited the source, my bad! Thanks for pointing that out.

Well, in my case,I'm doing a similar thing as in the source document. I have a measurement of the same signal by two different accelerometers (using LabView ofcourse) and now I want to compare those two signals to see the similarities in their output. I'm seeking a similar way of getting the correlation coefficients (and hence the figure 2.10 in the source document) in LabView.

[GerdW]

Hi akash,

I'm seeking a similar way of getting the correlation coefficients (and hence the figure 2.10 in the source document) in LabView.

I guess this "source document" explains how the authors calculated that figure…

(Btw. the correct spelling is LabVIEW. :D)

[Henrik_Volkers]

Well, the 'source' doesn't do it, but the a (self) reference

I had a look, again no investigation on uncertainty , I question the result unless it's not repeated with swapped sensor positions 😄 

In my opinion the influence of the setup (sensor positions and coupling, resonances of the fixure) is more relevant...

(and in Fig 7 .. a phase unwrap  would have been nice....)