Effects of Sampling Interval and Signal Length

Since the Nyquist frequency is half the sampling frequency, a higher sampling frequency will yield a spectrum in a wider frequency band.

This is an advantage because higher frequencies may then be examined. However, this necessitates the gathering and storage of larger amounts of data, and also increases computation time for the FFT or the DFT.

The resolution of the frequency spectrum is inversely proportional to the signal duration. For example, a 2 second long signal will have a frequency resolution of 0.5 Hz. This is desirable because then the frequency spectrum is smoother and has actual data at more frequencies. Once again, the drawback of having a long duration is increased storage space and computation time.