Astrophysics (index)

Signal-To-Noise Ratio

(SNR, S/N)
(ratio of the power of a signal to the power of the background noise)

Signal-To-Noise Ratio is a measure of a receiver's intended signal as opposed to background noise, expressed as a ratio of the average power of each. The power (of each) is directly related to the square of its root-mean-square amplitude i.e., the mean of the amplitude squared.

Signal-To-Noise Ratio is also expressed in Decibels, as 10 times the log 10 of the power ratio above.

In astrophysics, the signal-to-noise ratio may be used to characterize the possibility of sensing the output of an astrophysical phenomenon above the background signal and distortion.


Referenced by:
Radiometer Equation
Speckle Suppression