snr - Computer Definition
The ratio of the power of the wanted signal power to the power of the unwanted noise at a given point in a given system at a given time. SNR is expressed in decibels (dB). Impulse noise generally is measured in peak-signal to peak-noise ratio, and random noise in root-mean-square (RMS) signal to root-mean-square noise. See also dB, noise, power, and signal.