Nyquist rate

Definition: In signal processing theory: the sampling rate needed to turn an analogue signal to into an accurate digital representation of it is twice the highest frequency found in the analogue signal. * For example: if the highest frequency we want to record is 20kHz, then the Nyquist rate is 2 x 20kHZ = 40kHz = the sampling rate. * If the sampling rate is less than the Nyquist rate, artefacts are introduced: this is the cause of stair-stepping or jaggies seen in images. * Also known as Nyquist limit.* Harry Nyquist is the man to blame.

Related Terms: quality factor

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