# Translations:Prewhitening - book/1/en

In geophysical signal processing, most signals are truncated, which means that the tails of the signals are cut off and lost. If a valid autocorrelation is truncated, the resulting power spectrum might have negative values. In such a case, the truncated autocorrelation function is not an autocorrelation function in its own right. Such a truncated autocorrelation would lead to significant errors in processing. Thus, the truncated autocorrelation must be modified to make it legitimate. One way to modify the truncated autocorrelation is to taper it. Another way, called *prewhitening*, is to boost the value of its zero-lag coefficient. The goal is to make the power spectrum positive for all frequencies. Treitel and Lines (1982)^{[1]} show the relationship of prewhitening to inverse theory.

- ↑ Treitel, S., and L. Lines, 1982, Linear inverse theory and deconvolution: Geophysics,
**47**, 1153-1159.