Fr.: fréquence de Nyquist
The highest frequency that can be determined in a Fourier analysis of a discrete sampling of data.
Nyquist-Shannon sampling theorem
farbin-e nemunân-giri-ye Nyquist-Shannon
Fr.: théorème d'échantillonnage de Nyquist-Shannon
The minimum number of resolution elements required to properly sample a signal, such as a star image, without causing erroneous effects known as aliasing. For electronic imaging, this number is generally taken as 2 pixels across the seeing disk diameter at the half intensity points. Also called → Shannon's sampling theorem and → sampling theorem.
Named after Harry Nyquist (1889-1976), a Swedish-born American physicist, who made important contributions to information theory, and Claude Elwood Shannon (1916-2001), an American mathematician and pioneer of information theory; → theorem.