How to transform data from space domain to wavenumber domain through Fourier Transform?

I have a range of data of velocity in function of x,y (position) and time (t) [space domain] and I want to transform it into a range of data of frequency in function of kx and ky (wavenumbers) [wavenumber domain]. I read I can do it through 2D-Fourier Transform but I don't find the way.

In other words, I have a wavefield image at a given time instant in space domain (x,y) and I want to convert it in a wavefield image in wavenumber domain (kx,ky).

Thank you very much for the help!

Answer 1

[David Ding]

Hi Mo,

I see that you have a 2D wavefield in time domain, and you would like to convert the image into wavenumber domain.

In this case, you may simply call the "fft2" function, as follows:

% Assuming "I" is your data:
Y = fft2(X);

% Viewing the resulting wavenumber image
imagesc(abs(fftshift(Y)));

More information about MATLAB's "fft2" function is found below:

https://www.mathworks.com/help/matlab/ref/fft2.html?s_tid=doc_ta

Thanks,

David