Plotting Frequency vs. Wavenumber for Multiple Signals

I have three signals from an acoustic data set that I am trying to plot on a frequency vs. wavenumber basis. I am very new to MatLab and need guidance.

I have looked into this answer, but I need help relating it to my data: http://www.mathworks.com/matlabcentral/answers/40500-fft2-frequency-and-wavenumber

I followed this example: http://www.mathworks.com/help/matlab/ref/audioread.html

...So that my three signals (y1,y2,y3) are 66194100x2, and sample rate Fs=44100. How would I relate this to the above example to plot the three signals with the sample rate? I know this involves Fourier transform.

Again, I am not very savvy with MatLab, and I am looking for a simple explanation. I apologize, and thanks in advance.

Answer 1

[Star Strider]

Since Wavenumber is the spatial frequency, you would have to know the spatial separation of your signals (and if the two channels in each recording were equally spatially separated and the distance between all signals). The problem with three (or even six) recorded signals is that the number of samples would likely not give good spatial resolution with fft2.

As signals sampled in time, you have enough data for good time frequency resolution.

[yabby24]

How would I go about this though?

[Star Strider]

Use fft across the channels as well as with respect to time, or fft2.

You will need much more data to do a spatial fft (across channels or across time). You will not have any useful results with only three or six records.