Statistics of refractive pulsar scintillation - Effect of limited data length

Abstract

The dependence of the apparent modulation in the observed intensities of pulsars and extragalactic sources on the observing time/refractive time ratio is investigated using a direct simulation. As expected, the apparent modulation is found to decrease with the observing time/refractive time ratio. The calculations allow for the variance in the estimate and for the effect of using the sample mean rather than the true mean. The correction of the apparent modulation index is suggested in order to obtain a more meaningful estimate of the strength of modulation.