Discretiseringsartefact

Discretiseringsartefact, also known as aliasing, is a phenomenon that occurs when a continuous signal is sampled at a rate lower than the Nyquist rate, which is twice the highest frequency present in the signal. This process of converting a continuous signal into a discrete signal is known as discretisation. The Nyquist rate is the minimum sampling rate required to accurately reconstruct the original signal from its samples. When the sampling rate is below this threshold, the higher frequencies in the signal are not adequately captured, leading to the introduction of spurious frequencies in the sampled signal. These spurious frequencies are the discretiseringsartefakter, or aliasing artefacts, which can distort the signal and introduce errors in subsequent processing or analysis. To avoid aliasing, it is essential to sample the signal at a rate that is at least twice the highest frequency present in the signal. This can be achieved through various techniques, such as low-pass filtering the signal before sampling or using anti-aliasing filters.