Howtosignalprocessing
- What is aliasing in DFT?
- How aliasing is avoided while taking DFT of a sequence?
- What is aliasing in vibration analysis?
- What is aliasing in FFT?
What is aliasing in DFT?
Usually only a single period of the DTFT is plotted: In other words, when you use a sampling rate of , the frequencies 1 and are indistinguishable. This is called aliasing. In general, the continuous-time frequency is indistinguishable from any other frequency of the form , where is an integer.
How aliasing is avoided while taking DFT of a sequence?
Aliasing is generally avoided by applying low-pass filters or anti-aliasing filters (AAF) to the input signal before sampling and when converting a signal from a higher to a lower sampling rate.
What is aliasing in vibration analysis?
Aliasing occurs when an oscilloscope does not sample the signal fast enough to construct an accurate waveform record. The signal frequency is misidentified, and the waveforms displayed on an oscilloscope become indistinguishable. Aliasing is basically a form of undersampling.
What is aliasing in FFT?
Recognizing Aliasing in the FFT
It is common to have acquired signals with a fundamental frequency less than half the sample rate, but the harmonics of that signal may be greater than half the sample rate and they will alias. This shows up in the FFT as frequencies that fold back into the display.
