The law that is the basis for sampling continuous information. It states that the frequency of data sampling should be at least twice the maximum frequency at which the information might vary. This theorem should be observed in order to preserve patterns in the information or data, without introducing artificial, lower frequency patterns.
If we sample a signal more than two times it's maximum frequency component, the signal may be fully recovered.
A sampling theory law that states that to create an accurate digital representation of a sampled waveform you must sample the waveform, at least twice as fast as the highest frequency component contained in the waveform. Note that this is a minimum condition. In most applications, it is preferable to sample at a minimum of 3 to 4 times the highest expected frequency component.
the basic tenet in digital audio systems, stating that the highest throughput frequency in a sampling system must be equal to or less than one-half the sampling frequency. Theoretically, the highest frequency reproducible (without generating undesirable aliasing noise) by a system operating at a sampling rate of 48 kHz is 24 kHz. In practice, with the need for brickwall anti-aliasing filters, the actual upper-frequency response of such a system is somewhat less.
A theorem that, applied to image processing systems, states that the original image can be reconstructed without distortion if it is sampled at a spatial frequency (2f) at least twice that of the maximum constituent frequency (f).
The rule which states that a digital sampling system must have a sample rate at least twice as high as that of the highest frequency being sampled in order to avoid aliasing. Because anti-aliasing filters aren't perfect, the sampling frequency has usually to t be made more than twice that of the maximum input frequency.
The Nyquist theorem demands that a signal be sampled at at least twice its maximum frequency. To get an accurate picture of a waveform however, a sampling rate of 10 - 20 times the highest frequency is better.
