  We show that intermittency of noiselike emission, after propagation through a
scattering medium, affects the distribution of noise in the observed
correlation function. Intermittency also affects correlation of noise among
channels of the spectrum, but leaves the average spectrum, average correlation
function, and distribution of noise among channels of the spectrum unchanged.
Pulsars are examples of such sources: intermittent and affected by interstellar
propagation. We assume that the source emits Gaussian white noise, modulated by
a time-envelope. Propagation convolves the resulting time series with an
impulse-response function that represents effects of dispersion, scattering,
and absorption. We assume that this propagation kernel is shorter than the time
for an observer to accumulate a single spectrum. We show that rapidly-varying
intermittent emission tends to concentrate noise near the central lag of the
correlation function. We derive mathematical expressions for this effect, in
terms of the time envelope and the propagation kernel. We present examples,
discuss effects of background noise, and compare our results with observations.

Astrophysics of Galaxies;Instrumentation and Methods for Astrophysics