Effective Magnitude
Statistical measurements of signal power require an averaging method that accounts for both positive and negative fluctuations. The root mean square noise provides a single value that represents the heating power of the interference. It is calculated by squaring the instantaneous values, finding the mean, and taking the square root.
Statistical Weight
This metric gives more weight to large, infrequent spikes than a simple average would. In many applications, the root mean square noise is the best predictor of the total error in a measurement. It allows for the addition of independent noise sources by taking the root of the sum of their squares.
Crest Factor
Peak values can be much higher than the average power, especially in signals with high kurtosis. The ratio between the peak noise and the root mean square noise defines the crest factor of the interference. This ratio is important for ensuring that the signal does not clip the amplifier rails.
Bandwidth Limit
Filtering a signal reduces the total energy and lowers the observed magnitude. Standardized measurements specify the frequency range over which the root mean square noise is integrated. This value is used to calculate the signal to noise ratio of the system.
