Astrophysics (index)

Red Noise

(Brown Noise, Brownian Noise)
(noise tending toward lower frequencies)

Red Noise is a term for randomness in signals that is not totally uncorrelated (e.g., White Noise) but rather correlated to lower Frequencies (so-named because the color red comprises the lower frequencies of Visible Light). It is also called Brown Noise or Brownian Noise because Brownian Motion has this quality.

The term is used in discussion of signal detection. One example is the detection of Extra Solar Planets through Astrometry, for which measurement noise is due to equipment and Atmospheric anomalies.

For random noise that emphasizes other frequency ranges, the analogous terms Pink Noise, Blue Noise, and Violet Noise are used.