Discrete Fourier Transform from Noisy Sample
Drag points A, B, C in the Frequency Domain to set the amplitude and frequency of the signal components. Use the sliders to see how the Discrete Fourier Transform (DFT) is affected by the number of samples, sampling interval, and level of background noise. Use the slider to re-draw the output if it appears incorrect.
What happens to the Nyquist Frequency when you increase the Sampling Interval?
Aliasing is when the signal contains components higher than the Nyquist frequency. Slowly increase the frequency of component C (drag the point to the right) to the Nyquist frequency then beyond. What happens to the peak associated with this component?
Introduce some random noise using the slider. What happens to the DFT output?