Aliasing phenomenon

1. What is aliasing phenomenon?
2. What causes aliasing?
3. What is aliasing effect in sampling?
4. What is aliasing and how it is reduced?

What is aliasing phenomenon?

Aliasing is a phenomenon inherent to Doppler modalities which utilize intermittent sampling in which an insufficient sampling rate results in an inability to record direction and velocity accurately.

What causes aliasing?

Aliasing is the effect of new frequencies appearing in the sampled signal after reconstruction, that were not present in the original signal. It is caused by too low sample rate for sampling a particular signal or too high frequencies present in the signal for a particular sample rate.

What is aliasing effect in sampling?

Aliasing is an undesirable effect that is seen in sampled systems. When the input frequency is greater than half the sample frequency, the sampled points do not adequately represent the input signal. Inputs at these higher frequencies are observed at a lower, aliased frequency.

What is aliasing and how it is reduced?

Aliasing is characterized by the altering of output compared to the original signal because resampling or interpolation resulted in a lower resolution in images, a slower frame rate in terms of video or a lower wave resolution in audio. Anti-aliasing filters can be used to correct this problem.