Finding the aliased version of a signal

[Manchot]

Hey everyone. I've got a question pertaining to aliased signals. Is there a general method for finding what signal a function would alias to at a certain sampling rate? For example, suppose that you have a time-varying voltage V=sin(1/t), and you take data at a rate of 100 Hz, starting from when t=0. I picked this function because the initial frequency is infinite, and subsequently decreases.Therefore, what should happen is that at some point in time, whatever doing the sampling should eventually "get" the correct function. However, I'm more interested how one would interpolate the data in those first few moments when the signal does all kinds of crazy stuff. Is it possible to interpolate a function which "fits" those data points? Thanks!

 

[chroot]

If you perform an FFT of the signal, the power that really exists in bins past half the sampling rate will appear folded back into the Nyquist band.

- Warren

 

[Manchot]

Could you elaborate on that? I'm only a first year EE student, and I'm not clear on what you mean when you say "folded back into the Nyquist band."