| 释义 |
frequency spectrum
frequency spectrum[′frē·kwən·sē ‚spek·trəm] (physics) A plot of the distribution of the intensity of some type of electromagnetic or acoustic radiation as a function of frequency. (systems engineering) In the analysis of a random function of time, such as the amplitude of noise in a system, the limit as T approaches infinity of 1/(2π T) times the ensemble average of the squared magnitude of the amplitude of the Fourier transform of the function from -T to T. Also known as power-density spectrum; power spectrum; spectral density. frequency spectrum
fre·quen·cy spec·trumthe range of frequencies in a signal, used to describe the resolving power of an imaging system in radiology.See FREQSPEC
See FREQSPEC |