Signal averaging is a
signal processing
Signal processing is an electrical engineering subfield that focuses on analyzing, modifying and synthesizing ''signals'', such as sound, images, and scientific measurements. Signal processing techniques are used to optimize transmissions, ...
technique applied in the
time domain
Time domain refers to the analysis of mathematical functions, physical signals or time series of economic or environmental data, with respect to time. In the time domain, the signal or function's value is known for all real numbers, for the c ...
, intended to increase the strength of a
signal
In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The '' IEEE Transactions on Signal Processing' ...
relative to
noise
Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference aris ...
that is obscuring it. By averaging a set of
replicate measurements, the
signal-to-noise ratio (SNR) will be increased, ideally in proportion to the square root of the number of measurements.
Deriving the SNR for averaged signals
Assumed that
* Signal
is uncorrelated to noise, and noise
is uncorrelated :
.
* Signal power