signaalihäiriösuhteen

Signaalihäiriösuhde, often abbreviated as SNR or S/N, is a measurement used in science and engineering that compares the level of a desired signal to the level of background noise. It is defined as the ratio of signal power to noise power. A high signal-to-noise ratio indicates that the signal is strong relative to the noise, while a low signal-to-noise ratio means that the noise is significant compared to the signal.

The signal-to-noise ratio is typically expressed in decibels (dB). In mathematical terms, SNR in decibels is calculated as 10 times the logarithm (base 10) of the ratio of signal power to noise power. Alternatively, if the amplitudes of the signal and noise are known, and assuming they have the same impedance, the SNR can be calculated as 20 times the logarithm of the ratio of their amplitudes.

SNR is a crucial parameter in many fields, including telecommunications, audio engineering, and digital imaging. In telecommunications, a higher SNR generally leads to more reliable data transmission, as it reduces the likelihood of errors caused by noise. In audio systems, a high SNR means that the desired sound is clear and free from distracting background hum or hiss. In digital imaging, it relates to the clarity and detail of an image, with higher SNR indicating less grain or noise. Improving the SNR often involves reducing the noise sources or amplifying the signal.